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  • Optimizing a lot of Scanner.findWithinHorizon(pattern, 0) calls

    - by darvids0n
    I'm building a process which extracts data from 6 csv-style files and two poorly laid out .txt reports and builds output CSVs, and I'm fully aware that there's going to be some overhead searching through all that whitespace thousands of times, but I never anticipated converting about about 50,000 records would take 12 hours. Excerpt of my manual matching code (I know it's horrible that I use lists of tokens like that, but it was the best thing I could think of): public static String lookup(List<String> tokensBefore, List<String> tokensAfter) { String result = null; while(_match(tokensBefore)) { // block until all input is read if(id.hasNext()) { result = id.next(); // capture the next token that matches if(_matchImmediate(tokensAfter)) // try to match tokensAfter to this result return result; } else return null; // end of file; no match } return null; // no matches } private static boolean _match(List<String> tokens) { return _match(tokens, true); } private static boolean _match(List<String> tokens, boolean block) { if(tokens != null && !tokens.isEmpty()) { if(id.findWithinHorizon(tokens.get(0), 0) == null) return false; for(int i = 1; i <= tokens.size(); i++) { if (i == tokens.size()) { // matches all tokens return true; } else if(id.hasNext() && !id.next().matches(tokens.get(i))) { break; // break to blocking behaviour } } } else { return true; // empty list always matches } if(block) return _match(tokens); // loop until we find something or nothing else return false; // return after just one attempted match } private static boolean _matchImmediate(List<String> tokens) { if(tokens != null) { for(int i = 0; i <= tokens.size(); i++) { if (i == tokens.size()) { // matches all tokens return true; } else if(!id.hasNext() || !id.next().matches(tokens.get(i))) { return false; // doesn't match, or end of file } } return false; // we have some serious problems if this ever gets called } else { return true; // empty list always matches } } Basically wondering how I would work in an efficient string search (Boyer-Moore or similar). My Scanner id is scanning a java.util.String, figured buffering it to memory would reduce I/O since the search here is being performed thousands of times on a relatively small file. The performance increase compared to scanning a BufferedReader(FileReader(File)) was probably less than 1%, the process still looks to be taking a LONG time. I've also traced execution and the slowness of my overall conversion process is definitely between the first and last like of the lookup method. In fact, so much so that I ran a shortcut process to count the number of occurrences of various identifiers in the .csv-style files (I use 2 lookup methods, this is just one of them) and the process completed indexing approx 4 different identifiers for 50,000 records in less than a minute. Compared to 12 hours, that's instant. Some notes (updated): I don't necessarily need the pattern-matching behaviour, I only get the first field of a line of text so I need to match line breaks or use Scanner.nextLine(). All ID numbers I need start at position 0 of a line and run through til the first block of whitespace, after which is the name of the corresponding object. I would ideally want to return a String, not an int locating the line number or start position of the result, but if it's faster then it will still work just fine. If an int is being returned, however, then I would now have to seek to that line again just to get the ID; storing the ID of every line that is searched sounds like a way around that. Anything to help me out, even if it saves 1ms per search, will help, so all input is appreciated. Thankyou! Usage scenario 1: I have a list of objects in file A, who in the old-style system have an id number which is not in file A. It is, however, POSSIBLY in another csv-style file (file B) or possibly still in a .txt report (file C) which each also contain a bunch of other information which is not useful here, and so file B needs to be searched through for the object's full name (1 token since it would reside within the second column of any given line), and then the first column should be the ID number. If that doesn't work, we then have to split the search token by whitespace into separate tokens before doing a search of file C for those tokens as well. Generalised code: String field; for (/* each record in file A */) { /* construct the rest of this object from file A info */ // now to find the ID, if we can List<String> objectName = new ArrayList<String>(1); objectName.add(Pattern.quote(thisObject.fullName)); field = lookup(objectSearchToken, objectName); // search file B if(field == null) // not found in file B { lookupReset(false); // initialise scanner to check file C objectName.clear(); // not using the full name String[] tokens = thisObject.fullName.split(id.delimiter().pattern()); for(String s : tokens) objectName.add(Pattern.quote(s)); field = lookup(objectSearchToken, objectName); // search file C lookupReset(true); // back to file B } else { /* found it, file B specific processing here */ } if(field != null) // found it in B or C thisObject.ID = field; } The objectName tokens are all uppercase words with possible hyphens or apostrophes in them, separated by spaces. Much like a person's name. As per a comment, I will pre-compile the regex for my objectSearchToken, which is just [\r\n]+. What's ending up happening in file C is, every single line is being checked, even the 95% of lines which don't contain an ID number and object name at the start. Would it be quicker to use ^[\r\n]+.*(objectname) instead of two separate regexes? It may reduce the number of _match executions. The more general case of that would be, concatenate all tokensBefore with all tokensAfter, and put a .* in the middle. It would need to be matching backwards through the file though, otherwise it would match the correct line but with a huge .* block in the middle with lots of lines. The above situation could be resolved if I could get java.util.Scanner to return the token previous to the current one after a call to findWithinHorizon. I have another usage scenario. Will put it up asap.

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  • datalist edit mode.

    - by Ranjana
    i have a datalist control <ItemTemplate> <tr> <td height="31px"> <asp:Label ID="lblStudentName" runat="server" Text="StudentName :" Font-Bold="true"></asp:Label> <%# DataBinder.Eval(Container.DataItem, "StudentName") %> </td> <td height="31px"> <asp:LinkButton ID="lnkEdit" runat="server" CommandName="edit">Edit</asp:LinkButton> </td> </tr> <tr> <td> <asp:Label ID="lblAdmissionNo" runat="server" Text="AdmissionNo :" Font-Bold="true"></asp:Label> <%# DataBinder.Eval(Container.DataItem, "AdmissionNo")%> </td> </tr> <tr> <td height="31px"> <asp:Label ID="lblStudentRollNo" runat="server" Text="StdentRollNo :" Font-Bold="true"></asp:Label> <%# DataBinder.Eval(Container.DataItem, "StdentRollNo") %> </td> <td height="31px"> <asp:LinkButton ID="lnkEditroll" runat="server" CommandName="edit">Edit</asp:LinkButton> </td> </tr> </ItemTemplate> <EditItemTemplate> <tr> <td height="31px"> <asp:Label ID="lblStudentName" runat="server" Text="StudentName :" Font-Bold="true"></asp:Label> <asp:TextBox ID="txtProductName" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "StudentName") %>'></asp:TextBox> </td> <td> <asp:LinkButton ID="lnkUpdate" runat="server" CommandName="update">Update</asp:LinkButton> <asp:LinkButton ID="lnkCancel" runat="server" CommandName="cancel">Cancel</asp:LinkButton> </td> </tr> <tr> <td height="31px"> <asp:Label ID="lblAdmissionNo" runat="server" Text="AdmissionNo :" Font-Bold="true"></asp:Label> <%# DataBinder.Eval(Container.DataItem, "AdmissionNo")%> </td> </tr> <tr> <td height="31px"> <asp:Label ID="lblStudentRollNo" runat="server" Text="StudentRollNo :" Font-Bold="true"></asp:Label> <asp:TextBox ID="txtStudentRollNo" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "StdentRollNo") %>'></asp:TextBox> </td> <td> <asp:LinkButton ID="LinkButton1" runat="server" CommandName="update">Update</asp:LinkButton> <asp:LinkButton ID="LinkButton2" runat="server" CommandName="cancel">Cancel</asp:LinkButton> </td> </tr> </EditItemTemplate> <FooterTemplate> </table> </FooterTemplate> </asp:DataList> code behind: protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { DataTable dt = new DataTable(); dt = obj.GetSamples(); DataList1.DataSource = dt; DataList1.DataBind(); } } public void DataBind() { DataTable dt = new DataTable(); dt = obj.GetSamples(); DataList1.DataSource = dt; DataList1.DataBind(); } protected void DataList1_EditCommand1(object source, DataListCommandEventArgs e) { DataList1.EditItemIndex = e.Item.ItemIndex; DataBind(); } protected void DataList1_CancelCommand1(object source, DataListCommandEventArgs e) { DataList1.EditItemIndex = -1; DataBind(); } protected void DataList1_UpdateCommand1(object source, DataListCommandEventArgs e) { // Get the DataKey value associated with current Item Index. // int AdmissionNo = Convert.ToInt32(DataList1.DataKeys[e.Item.ItemIndex]); string AdmissionNo = DataList1.DataKeys[e.Item.ItemIndex].ToString(); // Get updated value entered by user in textbox control for // ProductName field. TextBox txtProductName; txtProductName = (TextBox)e.Item.FindControl("txtProductName"); TextBox txtStudentRollNo; txtStudentRollNo = (TextBox)e.Item.FindControl("txtStudentRollNo"); // string variable to store the connection string // retrieved from the connectionStrings section of web.config string connectionString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; // sql connection object SqlConnection mySqlConnection = new SqlConnection(connectionString); // sql command object initialized with update command text SqlCommand mySqlCommand = new SqlCommand("update SchoolAdmissionForm set StudentName=@studentname ,StdentRollNo=@studentroll where AdmissionNo=@admissionno", mySqlConnection); mySqlCommand.Parameters.Add("@studentname", SqlDbType.VarChar).Value = txtProductName.Text; mySqlCommand.Parameters.Add("@admissionno", SqlDbType.VarChar).Value = AdmissionNo; mySqlCommand.Parameters.Add("@studentroll", SqlDbType.VarChar).Value = txtStudentRollNo.Text; // check the connection state and open it accordingly. if (mySqlConnection.State == ConnectionState.Closed) mySqlConnection.Open(); // execute sql update query mySqlCommand.ExecuteNonQuery(); // check the connection state and close it accordingly. if (mySqlConnection.State == ConnectionState.Open) mySqlConnection.Close(); // reset the DataList mode back to its initial state DataList1.EditItemIndex = -1; DataBind(); // BindDataList(); } But it works fine.... but when i click edit command both the Fields 1.StudentName 2.StudentRollNo im getting textboxes to all the fields where i placed textbox when i click 'edit' command and not the particular field alone . but i should get oly the textbox visible to the field to which i clik as 'edit' , and the rest remain same without showing textboxes even though it is in editmode

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  • Something is making my page perform an Ajax call multiple times... [read: I've never been more frust

    - by Jack Webb-Heller
    NOTE: This is a long question. I've explained all the 'basics' at the top and then there's some further (optional) information for if you need it. Hi folks Basically last night this started happening at about 9PM whilst I was trying to restructure my code to make it a bit nicer for the designer to add a few bits to. I tried to fix it until 2AM at which point I gave up. Came back to it this morning, still baffled. I'll be honest with you, I'm a pretty bad Javascript developer. Since starting this project Javascript has been completely new to me and I've just learn as I went along. So please forgive me if my code structure is really bad (perhaps give a couple of pointers on how to improve it?). So, to the problem: to reproduce it, visit http://furnace.howcode.com (it's far from complete). This problem is a little confusing but I'd really appreciate the help. So in the second column you'll see three tabs The 'Newest' tab is selected by default. Scroll to the bottom, and 3 further results should be dynamically fetched via Ajax. Now click on the 'Top Rated' tab. You'll see all the results, but ordered by rating Scroll to the bottom of 'Top Rated'. You'll see SIX results returned. This is where it goes wrong. Only a further three should be returned (there are 18 entries in total). If you're observant you'll notice two 'blocks' of 3 returned. The first 'block' is the second page of results from the 'Newest' tab. The second block is what I just want returned. Did that make any sense? Never mind! So basically I checked this out in Firebug. What happens is, from a 'Clean' page (first load, nothing done) it calls ONE POST request to http://furnace.howcode.com/code/loadmore . But every time you load a new one of the tabs, it makes an ADDITIONAL POST request each time where there should normally only be ONE. So, can you help me? I'd really appreciate it! At this point you could start independent investigation or read on for a little further (optional) information. Thanks! Jack Further Info (may be irrelevant but here for reference): It's almost like there's some Javascript code or something being left behind that duplicates it each time. I thought it might be this code that I use to detect when the browser is scrolled to the bottom: var col = $('#col2'); col.scroll(function(){ if (col.outerHeight() == (col.get(0).scrollHeight - col.scrollTop())) loadMore(1); }); So what I thought was that code was left behind, and so every time you scroll #col2 (which contains different data for each tab) it detected that and added it for #newest as well. So, I made each tab click give #col2 a dynamic class - either .newestcol, .featuredcol, or .topratedcol. And then I changed the var col=$('.newestcol');dynamically so it would only detect it individually for each tab (makin' any sense?!). But hey, that didn't do anything. Another useful tidbit: here's the PHP for http://furnace.howcode.com/code/loadmore: $kind = $this->input->post('kind'); if ($kind == 1){ // kind is 1 - newest $start = $this->input->post('currentpage'); $data['query'] = "SELECT code.id AS codeid, code.title AS codetitle, code.summary AS codesummary, code.author AS codeauthor, code.rating AS rating, code.date, code_tags.*, tags.*, users.firstname AS authorname, users.id AS authorid, GROUP_CONCAT(tags.tag SEPARATOR ', ') AS taggroup FROM code, code_tags, tags, users WHERE users.id = code.author AND code_tags.code_id = code.id AND tags.id = code_tags.tag_id GROUP BY code_id ORDER BY date DESC LIMIT $start, 15 "; $this->load->view('code/ajaxlist',$data); } elseif ($kind == 2) { // kind is 2 - featured So my jQuery code sends a variable 'kind'. If it's 1, it runs the query for Newest, etc. etc. The PHP code for furnace.howcode.com/code/ajaxlist is: <?php // Our query base // SELECT * FROM code ORDER BY date DESC $query = $this->db->query($query); foreach($query->result() as $row) { ?> <script type="text/javascript"> $('#title-<?php echo $row->codeid;?>').click(function() { var form_data = { id: <?php echo $row->codeid; ?> }; $('#col3').fadeOut('slow', function() { $.ajax({ url: "<?php echo site_url('code/viewajax');?>", type: 'POST', data: form_data, success: function(msg) { $('#col3').html(msg); $('#col3').fadeIn('fast'); } }); }); }); </script> <div class="result"> <div class="resulttext"> <div id="title-<?php echo $row->codeid; ?>" class="title"> <?php echo anchor('#',$row->codetitle); ?> </div> <div class="summary"> <?php echo $row->codesummary; ?> </div> <!-- Now insert the 5-star rating system --> <?php include($_SERVER['DOCUMENT_ROOT']."/fivestars/5star.php");?> <div class="bottom"> <div class="author"> Submitted by <?php echo anchor('auth/profile/'.$row->authorid,''.$row->authorname);?> </div> <?php // Now we need to take the GROUP_CONCATted tags and split them using the magic of PHP into seperate tags $tagarray = explode(", ", $row->taggroup); foreach ($tagarray as $tag) { ?> <div class="tagbutton" href="#"> <span><?php echo $tag; ?></span> </div> <?php } ?> </div> </div> </div> <?php } echo "&nbsp;";?> <script type="text/javascript"> var newpage = <?php echo $this->input->post('currentpage') + 15;?>; </script> So that's everything in PHP. The rest you should be able to view with Firebug or by viewing the Source code. I've put all the Tab/clicking/Ajaxloading bits in the tags at the very bottom. There's a comment before it all kicks off. Thanks so much for your help!

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  • Please help to clean up my RoR development environment

    - by PeterWong
    I started RoR development a few months ago, and being new to Mac... Time flies and now I have a lot different ruby versions, rails versions and gems versions located everywhere......And currently I installed rvm and things got even worst, all things messed! And so I started want to clean all things and use rvm again! I want to uninstall all gems, all rails, and all ruby versions, except the system's default one (the very old one born with the mac). Or any other better solutions or suggestions!? Please help! there is some info that I think will be useful: which -a ruby /opt/local/bin/ruby /opt/local/bin/ruby /usr/local/bin/ruby /usr/bin/ruby /usr/local/bin/ruby which -a rails /usr/local/bin/rails /usr/bin/rails /usr/local/bin/rails which -a compass # simliar for rspec and many other gems /usr/local/bin/compass /usr/local/bin/compass gem list *** LOCAL GEMS *** abstract (1.0.0) actionmailer (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4) actionpack (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4) activemodel (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2) activerecord (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4) activeresource (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4) activesupport (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4) addressable (2.2.2) arel (2.0.6, 1.0.1, 1.0.0.rc1) authlogic (2.1.6, 2.1.3) aws-s3 (0.6.2) base32 (0.1.2) block_helpers (0.3.3) bluecloth (2.0.9) bowline (0.9.4) bowline-bundler (0.0.4) bson (1.1.2) builder (2.1.2) bundler (1.0.2, 1.0.0) compass (0.10.6) crack (0.1.7) devise (1.1.3) diff-lcs (1.1.2) differ (0.1.1) dynamic_form (1.1.3) engineyard (1.3.1) engineyard-serverside-adapter (1.3.3) erubis (2.6.6) escape (0.0.4) extlib (0.9.15) facebooker (1.0.75) faker (0.3.1) faraday (0.5.3, 0.5.2) fast_gettext (0.5.10, 0.4.17) fastercsv (1.5.3) fastthread (1.0.7) ffi (0.6.3) formatize (1.0.1) formtastic (1.1.0, 1.0.1) gemcutter (0.5.0) gettext (2.1.0) git (1.2.5) gosu (0.7.25 universal-darwin) haml (3.0.24, 3.0.23, 3.0.22, 3.0.21, 3.0.18) haml-rails (0.3.4) heroku (1.10.13, 1.9.13) highline (1.5.2) hirb (0.3.4, 0.3.3) hpricot (0.8.2) i18n (0.5.0, 0.4.2, 0.4.1, 0.3.7) jeweler (1.4.0) json (1.4.6) json_pure (1.4.3) linkedin (0.1.8) locale (2.0.5) mail (2.2.12, 2.2.11, 2.2.10, 2.2.9, 2.2.7, 2.2.6.1) memcache-client (1.8.5) meta_search (0.9.8, 0.9.7.2, 0.9.7.1, 0.9.6, 0.9.4) mime-types (1.16) mongo (1.1.2) mongoid (2.0.0.beta.20) multi_json (0.0.5) multipart-post (1.0.1) mysql (2.8.1) mysql2 (0.2.6, 0.2.4, 0.2.3) net-ldap (0.1.1) nice-ffi (0.4) nokogiri (1.4.4, 1.4.2) oa-basic (0.1.6) oa-core (0.1.6) oa-enterprise (0.1.6) oa-oauth (0.1.6) oa-openid (0.1.6) oauth (0.4.4, 0.4.3, 0.4.1) oauth-plugin (0.4.0.pre1) oauth2 (0.1.0) omniauth (0.1.6) paperclip (2.3.6, 2.3.4, 2.3.1.1) passenger (2.2.12) polyglot (0.3.1) pyu-ruby-sasl (0.0.3.2) querybuilder (0.9.2, 0.5.9) rack (1.2.1, 1.1.0, 1.0.1) rack-cache (0.5.3) rack-cache-purge (0.0.2, 0.0.1) rack-mount (0.6.13) rack-openid (1.2.0) rack-test (0.5.6, 0.5.4) railroady (0.11.2) rails (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2, 2.3.9, 2.3.5, 2.3.4) railties (3.0.3, 3.0.1, 3.0.0, 3.0.0.rc2) rake (0.8.7) RedCloth (3.0.4) rest-client (1.6.1) roxml (3.1.5) rscribd (1.2.0) rspec (2.3.0, 2.2.0, 2.1.0, 2.0.1) rspec-core (2.3.0, 2.2.1, 2.1.0, 2.0.1) rspec-expectations (2.3.0, 2.2.0, 2.1.0, 2.0.1) rspec-mocks (2.3.0, 2.2.0, 2.1.0, 2.0.1) rspec-rails (2.3.0, 2.2.0, 2.1.0, 2.0.1) ruby-hmac (0.4.0) ruby-mysql (2.9.3) ruby-ole (1.2.10.1) ruby-openid (2.1.8) ruby-openid-apps-discovery (1.2.0) ruby-recaptcha (1.0.2, 1.0.0) ruby-sdl-ffi (0.3) ruby-termios (0.9.6) ruby_parser (2.0.5) rubyforge (2.0.4) rubygame (2.6.4) rubygems-update (1.3.7) rubyless (0.7.0, 0.6.0, 0.3.5) rubyntlm (0.1.1) rubyzip2 (2.0.1) scribd_fu (2.0.6) searchlogic (2.4.27, 2.4.23) sequel (3.16.0, 3.15.0, 3.13.0) sexp_processor (3.0.5) shoulda (2.11.3) sinatra (1.0) slim (0.8.0) slim-rails (0.1.2) spreadsheet (0.6.4.1) sqlite3-ruby (1.3.2, 1.3.1) ssl_requirement (0.1.0) subdomain-fu (1.0.0.beta2, 0.5.4) supermodel (0.1.4) syntax (1.0.0) taps (0.3.13, 0.3.11) templater (1.0.0) temple (0.1.6) text-format (1.0.0) text-hyphen (1.0.0) thor (0.14.6, 0.14.4, 0.14.3, 0.14.1, 0.14.0) tilt (1.1) treetop (1.4.9, 1.4.8) tzinfo (0.3.23) uuidtools (2.1.1, 2.0.0) validates_timeliness (3.0.0.beta.4, 2.3.1) warden (0.10.7) will_paginate (3.0.pre2, 2.3.15, 2.3.14) xml-simple (1.0.12) ya2yaml (0.30) yajl-ruby (0.7.8, 0.7.7) yamltest (0.7.0) zena (0.16.9, 0.16.8) ====== I have ran sudo rvm implode and sudo rm -rf ~/.rvm, so no rvm now. gem env RubyGems Environment: - RUBYGEMS VERSION: 1.3.7 - RUBY VERSION: 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10.2.0] - INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/1.8 - RUBY EXECUTABLE: /usr/local/bin/ruby - EXECUTABLE DIRECTORY: /usr/local/bin - RUBYGEMS PLATFORMS: - ruby - x86-darwin-10 - GEM PATHS: - /usr/local/lib/ruby/gems/1.8 - /Users/peter/.gem/ruby/1.8 - GEM CONFIGURATION: - :update_sources => true - :verbose => true - :benchmark => false - :backtrace => false - :bulk_threshold => 1000 - :sources => ["http://rubygems.org/", "http://gems.github.com"] - REMOTE SOURCES: - http://rubygems.org/ - http://gems.github.com === ls -al /usr/local/lib/ total 5704 drwxr-xr-x 7 root wheel 238 Jun 1 2010 . drwxr-xr-x 9 root wheel 306 Dec 15 16:20 .. -rw-r--r-- 1 root wheel 1717208 Jun 1 2010 libruby-static.a -rwxr-xr-x 1 root wheel 1191880 Jun 1 2010 libruby.1.8.7.dylib lrwxrwxrwx 1 root wheel 19 Jun 1 2010 libruby.1.8.dylib -> libruby.1.8.7.dylib lrwxrwxrwx 1 root wheel 19 Jun 1 2010 libruby.dylib -> libruby.1.8.7.dylib drwxr-xr-x 6 root wheel 204 Jun 1 2010 ruby

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  • Passing XML markers to Google Map

    - by djmadscribbler
    I've been creating a V3 Google map based on this example from Mike Williams http://www.geocodezip.com/v3_MW_example_map3.html I've run into a bit of a problem though. If I have no parameters in my URL then I get the error "id is undefined idmarkers [id.toLowerCase()] = marker;" in Firebug and only one marker will show up. If I have a parameter (?id=105 for example) then all the sidebar links say 105 (or whatever the parameter in the URL was) instead of their respective label as listed in the XML file and a random infowindow will be opened instead of the window for the id in the URL. Here is my javascript: var map = null; var lastmarker = null; // ========== Read paramaters that have been passed in ========== // Before we go looking for the passed parameters, set some defaults // in case there are no parameters var id; var index = -1; // these set the initial center, zoom and maptype for the map // if it is not specified in the query string var lat = 42.194741; var lng = -121.700301; var zoom = 18; var maptype = google.maps.MapTypeId.HYBRID; function MapTypeId2UrlValue(maptype) { var urlValue = 'm'; switch (maptype) { case google.maps.MapTypeId.HYBRID: urlValue = 'h'; break; case google.maps.MapTypeId.SATELLITE: urlValue = 'k'; break; case google.maps.MapTypeId.TERRAIN: urlValue = 't'; break; default: case google.maps.MapTypeId.ROADMAP: urlValue = 'm'; break; } return urlValue; } // If there are any parameters at eh end of the URL, they will be in location.search // looking something like "?marker=3" // skip the first character, we are not interested in the "?" var query = location.search.substring(1); // split the rest at each "&" character to give a list of "argname=value" pairs var pairs = query.split("&"); for (var i = 0; i < pairs.length; i++) { // break each pair at the first "=" to obtain the argname and value var pos = pairs[i].indexOf("="); var argname = pairs[i].substring(0, pos).toLowerCase(); var value = pairs[i].substring(pos + 1).toLowerCase(); // process each possible argname - use unescape() if theres any chance of spaces if (argname == "id") { id = unescape(value); } if (argname == "marker") { index = parseFloat(value); } if (argname == "lat") { lat = parseFloat(value); } if (argname == "lng") { lng = parseFloat(value); } if (argname == "zoom") { zoom = parseInt(value); } if (argname == "type") { // from the v3 documentation 8/24/2010 // HYBRID This map type displays a transparent layer of major streets on satellite images. // ROADMAP This map type displays a normal street map. // SATELLITE This map type displays satellite images. // TERRAIN This map type displays maps with physical features such as terrain and vegetation. if (value == "m") { maptype = google.maps.MapTypeId.ROADMAP; } if (value == "k") { maptype = google.maps.MapTypeId.SATELLITE; } if (value == "h") { maptype = google.maps.MapTypeId.HYBRID; } if (value == "t") { maptype = google.maps.MapTypeId.TERRAIN; } } } // this variable will collect the html which will eventually be placed in the side_bar var side_bar_html = ""; // arrays to hold copies of the markers and html used by the side_bar // because the function closure trick doesnt work there var gmarkers = []; var idmarkers = []; // global "map" variable var map = null; // A function to create the marker and set up the event window function function createMarker(point, icon, label, html) { var contentString = html; var marker = new google.maps.Marker({ position: point, map: map, title: label, icon: icon, zIndex: Math.round(point.lat() * -100000) << 5 }); marker.id = id; marker.index = gmarkers.length; google.maps.event.addListener(marker, 'click', function () { lastmarker = new Object; lastmarker.id = marker.id; lastmarker.index = marker.index; infowindow.setContent(contentString); infowindow.open(map, marker); }); // save the info we need to use later for the side_bar gmarkers.push(marker); idmarkers[id.toLowerCase()] = marker; // add a line to the side_bar html side_bar_html += '<a href="javascript:myclick(' + (gmarkers.length - 1) + ')">' + id + '<\/a><br>'; } // This function picks up the click and opens the corresponding info window function myclick(i) { google.maps.event.trigger(gmarkers[i], "click"); } function makeLink() { var mapinfo = "lat=" + map.getCenter().lat().toFixed(6) + "&lng=" + map.getCenter().lng().toFixed(6) + "&zoom=" + map.getZoom() + "&type=" + MapTypeId2UrlValue(map.getMapTypeId()); if (lastmarker) { var a = "/about/map/default.aspx?id=" + lastmarker.id + "&" + mapinfo; var b = "/about/map/default.aspx?marker=" + lastmarker.index + "&" + mapinfo; } else { var a = "/about/map/default.aspx?" + mapinfo; var b = a; } document.getElementById("idlink").innerHTML = '<a href="' + a + '" id=url target=_new>- Link directly to this page by id</a> (id in xml file also entry &quot;name&quot; in sidebar menu)'; document.getElementById("indexlink").innerHTML = '<a href="' + b + '" id=url target=_new>- Link directly to this page by index</a> (position in gmarkers array)'; } function initialize() { // create the map var myOptions = { zoom: zoom, center: new google.maps.LatLng(lat, lng), mapTypeId: maptype, mapTypeControlOptions: { style: google.maps.MapTypeControlStyle.DROPDOWN_MENU }, navigationControl: true, mapTypeId: google.maps.MapTypeId.HYBRID }; map = new google.maps.Map(document.getElementById("map_canvas"), myOptions); var stylesarray = [ { featureType: "poi", elementType: "labels", stylers: [ { visibility: "off" } ] }, { featureType: "landscape.man_made", elementType: "labels", stylers: [ { visibility: "off" } ] } ]; var options = map.setOptions({ styles: stylesarray }); // Make the link the first time when the page opens makeLink(); // Make the link again whenever the map changes google.maps.event.addListener(map, 'maptypeid_changed', makeLink); google.maps.event.addListener(map, 'center_changed', makeLink); google.maps.event.addListener(map, 'bounds_changed', makeLink); google.maps.event.addListener(map, 'zoom_changed', makeLink); google.maps.event.addListener(map, 'click', function () { lastmarker = null; makeLink(); infowindow.close(); }); // Read the data from example.xml downloadUrl("example.xml", function (doc) { var xmlDoc = xmlParse(doc); var markers = xmlDoc.documentElement.getElementsByTagName("marker"); for (var i = 0; i < markers.length; i++) { // obtain the attribues of each marker var lat = parseFloat(markers[i].getAttribute("lat")); var lng = parseFloat(markers[i].getAttribute("lng")); var point = new google.maps.LatLng(lat, lng); var html = markers[i].getAttribute("html"); var label = markers[i].getAttribute("label"); var icon = markers[i].getAttribute("icon"); // create the marker var marker = createMarker(point, icon, label, html); } // put the assembled side_bar_html contents into the side_bar div document.getElementById("side_bar").innerHTML = side_bar_html; // ========= If a parameter was passed, open the info window ========== if (id) { if (idmarkers[id]) { google.maps.event.trigger(idmarkers[id], "click"); } else { alert("id " + id + " does not match any marker"); } } if (index > -1) { if (index < gmarkers.length) { google.maps.event.trigger(gmarkers[index], "click"); } else { alert("marker " + index + " does not exist"); } } }); } var infowindow = new google.maps.InfoWindow( { size: new google.maps.Size(150, 50) }); google.maps.event.addDomListener(window, "load", initialize); And here is an example of my XML formatting <marker lat="42.196175" lng="-121.699224" html="This is the information about 104" iconimage="/about/map/images/104.png" label="104" />

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  • Implementing a robust async stream reader

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output, but that is a detail and does not play an important role. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

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  • Ideas for multiplatform encrypted java mobile storage system

    - by Fernando Miguélez
    Objective I am currently designing the API for a multiplatform storage system that would offer same interface and capabilities accross following supported mobile Java Platforms: J2ME. Minimum configuration/profile CLDC 1.1/MIDP 2.0 with support for some necessary JSRs (JSR-75 for file storage). Android. No minimum platform version decided yet, but rather likely could be API level 7. Blackberry. It would use the same base source of J2ME but taking advantage of some advaced capabilities of the platform. No minimum configuration decided yet (maybe 4.6 because of 64 KB limitation for RMS on 4.5). Basically the API would sport three kind of stores: Files. These would allow standard directory/file manipulation (read/write through streams, create, mkdir, etc.). Preferences. It is a special store that handles properties accessed through keys (Similar to plain old java properties file but supporting some improvements such as different value data types such as SharedPreferences on Android platform) Local Message Queues. This store would offer basic message queue functionality. Considerations Inspired on JSR-75, all types of stores would be accessed in an uniform way by means of an URL following RFC 1738 conventions, but with custom defined prefixes (i.e. "file://" for files, "prefs://" for preferences or "queue://" for message queues). The address would refer to a virtual location that would be mapped to a physical storage object by each mobile platform implementation. Only files would allow hierarchical storage (folders) and access to external extorage memory cards (by means of a unit name, the same way as in JSR-75, but that would not change regardless of underlying platform). The other types would only support flat storage. The system should also support a secure version of all basic types. The user would indicate it by prefixing "s" to the URL (i.e. "sfile://" instead of "file://"). The API would only require one PIN (introduced only once) to access any kind of secure object types. Implementation issues For the implementation of both plaintext and encrypted stores, I would use the functionality available on the underlying platforms: Files. These are available on all platforms (J2ME only with JSR-75, but it is mandatory for our needs). The abstract File to actual File mapping is straight except for addressing issues. RMS. This type of store available on J2ME (and Blackberry) platforms is convenient for Preferences and maybe Message Queues (though depending on performance or size requirements these could be implemented by means of normal files). SharedPreferences. This type of storage, only available on Android, would match Preferences needs. SQLite databases. This could be used for message queues on Android (and maybe Blackberry). When it comes to encryption some requirements should be met: To ease the implementation it will be carried out on read/write operations basis on streams (for files), RMS Records, SharedPreferences key-value pairs, SQLite database columns. Every underlying storage object should use the same encryption key. Handling of encrypted stores should be the same as the unencrypted counterpart. The only difference (from the user point of view) accessing an encrypted store would be the addressing. The user PIN provides access to any secure storage object, but the change of it would not require to decrypt/re-encrypt all the encrypted data. Cryptographic capabilities of underlying platform should be used whenever it is possible, so we would use: J2ME: SATSA-CRYPTO if it is available (not mandatory) or lightweight BoncyCastle cryptographic framework for J2ME. Blackberry: RIM Cryptographic API or BouncyCastle Android: JCE with integraced cryptographic provider (BouncyCastle?) Doubts Having reached this point I was struck by some doubts about what solution would be more convenient, taking into account the limitation of the plataforms. These are some of my doubts: Encryption Algorithm for data. Would AES-128 be strong and fast enough? What alternatives for such scenario would you suggest? Encryption Mode. I have read about the weakness of ECB encryption versus CBC, but in this case the first would have the advantage of random access to blocks, which is interesting for seek functionality on files. What type of encryption mode would you choose instead? Is stream encryption suitable for this case? Key generation. There could be one key generated for each storage object (file, RMS RecordStore, etc.) or just use one for all the objects of the same type. The first seems "safer", though it would require some extra space on device. In your opinion what would the trade-offs of each? Key storage. For this case using a standard JKS (or PKCS#12) KeyStore file could be suited to store encryption keys, but I could also define a smaller structure (encryption-transformation / key data / checksum) that could be attached to each storage store (i.e. using addition files with the same name and special extension for plain files or embedded inside other types of objects such as RMS Record Stores). What approach would you prefer? And when it comes to using a standard KeyStore with multiple-key generation (given this is your preference), would it be better to use a record-store per storage object or just a global KeyStore keeping all keys (i.e. using the URL identifier of abstract storage object as alias)? Master key. The use of a master key seems obvious. This key should be protected by user PIN (introduced only once) and would allow access to the rest of encryption keys (they would be encrypted by means of this master key). Changing the PIN would only require to reencrypt this key and not all the encrypted data. Where would you keep it taking into account that if this got lost all data would be no further accesible? What further considerations should I take into account? Platform cryptography support. Do SATSA-CRYPTO-enabled J2ME phones really take advantage of some dedicated hardware acceleration (or other advantage I have not foreseen) and would this approach be prefered (whenever possible) over just BouncyCastle implementation? For the same reason is RIM Cryptographic API worth the license cost over BouncyCastle? Any comments, critics, further considerations or different approaches are welcome.

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  • How to retrive message list from p2p

    - by cre-johnny07
    Hello friends I have a messaging system that uses p2p. Each peer has a incoming message list and a outgoing message list. What I need to do is whenever a new peer will join the mesh he will get the all the incoming messages from other peers and add those into it's own incoming message list. Now I know when I get the other peer info from I can ask them to give their own list to me. But I'm not finding the way how..? Any suggestion on this or help would be highly appreciated. I'm giving my code below. Thanking in Advance Johnny #region Instance Fields private string strOrigin = ""; //the chat member name private string m_Member; //the channel instance where we execute our service methods against private IServerChannel m_participant; //the instance context which in this case is our window since it is the service host private InstanceContext m_site; //our binding transport for the p2p mesh private NetPeerTcpBinding m_binding; //the factory to create our chat channel private ChannelFactory<IServerChannel> m_channelFactory; //an interface provided by the channel exposing events to indicate //when we have connected or disconnected from the mesh private IOnlineStatus o_statusHandler; //a generic delegate to execute a thread against that accepts no args private delegate void NoArgDelegate(); //an object to hold user details private IUserService userService; //an Observable Collection of object to get all the Application Instance Details in databas ObservableCollection<AppLoginInstance> appLoginInstances; // an Observable Collection of object to get all Incoming Messages types ObservableCollection<MessageType> inComingMessageTypes; // an Observable Collection of object to get all Outgoing Messages ObservableCollection<PDCL.ERP.DataModels.Message> outGoingMessages; // an Observable Collection of object to get all Incoming Messages ObservableCollection<PDCL.ERP.DataModels.Message> inComingMessages; //an Event Aggregator to publish event for other modules to subscribe private readonly IEventAggregator eventAggregator; /// <summary> /// an IUnityCOntainer to get the container /// </summary> private IUnityContainer container; private RefreshConnectionStatus refreshConnectionStatus; private RefreshConnectionStatusEventArgs args; private ReplyRequestMessage replyMessageRequest; private ReplyRequestMessageEventArgs eventsArgs; #endregion public P2pMessageService(IUserService UserService, IEventAggregator EventAggregator, IUnityContainer container) { userService = UserService; this.container = container; appLoginInstances = new ObservableCollection<AppLoginInstance>(); inComingMessageTypes = new ObservableCollection<MessageType>(); inComingMessages = new ObservableCollection<PDCL.ERP.DataModels.Message>(); outGoingMessages = new ObservableCollection<PDCL.ERP.DataModels.Message>(); this.args = new RefreshConnectionStatusEventArgs(); this.eventsArgs = new ReplyRequestMessageEventArgs(); this.eventAggregator = EventAggregator; this.refreshConnectionStatus = this.eventAggregator.GetEvent<RefreshConnectionStatus>(); this.replyMessageRequest = this.eventAggregator.GetEvent<ReplyRequestMessage>(); } #region IOnlineStatus Event Handlers void ostat_Offline(object sender, EventArgs e) { // we could update a status bar or animate an icon to //indicate to the user they have disconnected from the mesh //currently i don't have a "disconnect" button but adding it //should be trivial if you understand the rest of this code } void ostat_Online(object sender, EventArgs e) { try { m_participant.Join(userService.AppInstance); } catch (Exception Ex) { Logger.Exception(Ex, Ex.TargetSite.Name + ": " + Ex.TargetSite + ": " + Ex.Message); } } #endregion #region IServer Members //this method gets called from a background thread to //connect the service client to the p2p mesh specified //by the binding info in the app.config public void ConnectToMesh() { try { m_site = new InstanceContext(this); //use the binding from the app.config with default settings m_binding = new NetPeerTcpBinding("P2PMessageBinding"); m_channelFactory = new DuplexChannelFactory<IServerChannel>(m_site, "P2PMessageEndPoint"); m_participant = m_channelFactory.CreateChannel(); o_statusHandler = m_participant.GetProperty<IOnlineStatus>(); o_statusHandler.Online += new EventHandler(ostat_Online); o_statusHandler.Offline += new EventHandler(ostat_Offline); //m_participant.InitializeMesh(); //this.appLoginInstances.Add(this.userService.AppInstance); BackgroundWorkerHelper.DoWork<object>(() => { //this is an empty unhandled method on the service interface. //why? because for some reason p2p clients don't try to connect to the mesh //until the first service method call. so to facilitate connecting i call this method //to get the ball rolling. m_participant.InitializeMesh(); //SynchronizeMessage(this.inComingMessages); return new object(); }, arg => { }); this.appLoginInstances.Add(this.userService.AppInstance); } catch (Exception Ex) { Logger.Exception(Ex, Ex.TargetSite.Name + ": " + Ex.TargetSite + ": " + Ex.Message); } } public void Join(AppLoginInstance obj) { try { // Adding Instance to the PeerList if (appLoginInstances.SingleOrDefault(a => a.InstanceId == obj.InstanceId)==null) { appLoginInstances.Add(obj); this.refreshConnectionStatus.Publish(new RefreshConnectionStatusEventArgs() { Status = m_channelFactory.State }); } //this will retrieve any new members that have joined before the current user m_participant.SynchronizeMemberList(userService.AppInstance); } catch(Exception Ex) { Logger.Exception(Ex,Ex.TargetSite.Name + ": " + Ex.TargetSite + ": " + Ex.Message); } } /// <summary> /// Synchronizes member list /// </summary> /// <param name="obj">The AppLoginInstance Param</param> public void SynchronizeMemberList(AppLoginInstance obj) { //as member names come in we simply disregard duplicates and //add them to the member list, this way we can retrieve a list //of members already in the chatroom when we enter at any time. //again, since this is just an example this is the simplified //way to do things. the correct way would be to retrieve a list //of peernames and retrieve the metadata from each one which would //tell us what the member name is and add it. we would want to check //this list when we join the mesh to make sure our member name doesn't //conflict with someone else try { if (appLoginInstances.SingleOrDefault(a => a.InstanceId == obj.InstanceId) == null) { appLoginInstances.Add(obj); } } catch (Exception Ex) { Logger.Exception(Ex, Ex.TargetSite.Name + ": " + Ex.TargetSite + ": " + Ex.Message); } } /// <summary> /// This methos broadcasts the mesasge to all peers. /// </summary> /// <param name="msg">The whole message which is to be broadcasted</param> /// <param name="securityLevels"> Level of security</param> public void BroadCastMsg(PDCL.ERP.DataModels.Message msg, List<string> securityLevels) { try { foreach (string s in securityLevels) { if (this.userService.IsInRole(s)) { if (this.inComingMessages.Count == 0 && msg.CreatedByApp != this.userService.AppInstanceId) { this.inComingMessages.Add(msg); } else if (this.inComingMessages.SingleOrDefault(a => a.MessageId == msg.MessageId) == null && msg.CreatedByApp != this.userService.AppInstanceId) { this.inComingMessages.Add(msg); } } } } catch (Exception Ex) { Logger.Exception(Ex, Ex.TargetSite.Name + ": " + Ex.TargetSite + ": " + Ex.Message); } } /// <summary> /// /// </summary> /// <param name="msg">The Message to denyed</param> public void BroadCastReplyMsg(PDCL.ERP.DataModels.Message msg) { try { //if (this.inComingMessages.SingleOrDefault(a => a.MessageId == msg.MessageId) != null) //{ this.replyMessageRequest.Publish(new ReplyRequestMessageEventArgs() { Message = msg }); this.inComingMessages.Remove(this.inComingMessages.SingleOrDefault(o => o.MessageId == msg.MessageId)); //} } catch (Exception ex) { Logger.Exception(ex, ex.TargetSite.Name + ": " + ex.TargetSite + ": " + ex.Message); } } //again we need to sync the worker thread with the UI thread via Dispatcher public void Whisper(string Member, string MemberTo, string Message) { } public void InitializeMesh() { //do nothing } public void Leave(AppLoginInstance obj) { if (this.appLoginInstances.SingleOrDefault(a => a.InstanceId == obj.InstanceId) != null) { this.appLoginInstances.Remove(this.appLoginInstances.Single(a => a.InstanceId == obj.InstanceId)); } } //public void SynchronizeRemoveMemberList(AppLoginInstance obj) //{ // if (appLoginInstances.SingleOrDefault(a => a.InstanceId == obj.InstanceId) != null) // { // appLoginInstances.Remove(obj); // } //} #endregion

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  • Implementing a robust async stream reader for a console

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. Edit: There are comments below correctly stating that since the data is coming from a stream, there is absolutely nothing that the receiver can infer about the structure of the data unless it is fully prepared to parse it. What I am trying to do here is leverage the "flush the output" "structure" that the owner of the console imparts while writing on it. I am prepared to assume (better: allow my caller to have the option to assume) that the OS will pass me the data written between two flushes of the stream in exactly one piece. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

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  • (PHP) Validation, Security and Speed - Does my app have these?

    - by Devner
    Hi all, I am currently working on a building community website in PHP. This contains forms that a user can fill right from registration to lot of other functionality. I am not an Object-oriented guy, so I am using functions most of the time to handle my application. I know I have to learn OOPS, but currently need to develop this website and get it running soon. Anyway, here's a sample of what I let my app. do: Consider a page (register.php) that has a form where a user has 3 fields to fill up, say: First Name, Last Name and Email. Upon submission of this form, I want to validate the form and show the corresponding errors to the users: <form id="form1" name="form1" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> <label for="name">Name:</label> <input type="text" name="name" id="name" /><br /> <label for="lname">Last Name:</label> <input type="text" name="lname" id="lname" /><br /> <label for="email">Email:</label> <input type="text" name="email" id="email" /><br /> <input type="submit" name="submit" id="submit" value="Submit" /> </form> This form will POST the info to the same page. So here's the code that will process the POST'ed info: <?php require("functions.php"); if( isset($_POST['submit']) ) { $errors = fn_register(); if( count($errors) ) { //Show error messages } else { //Send welcome mail to the user or do database stuff... } } ?> <?php //functions.php page: function sql_quote( $value ) { if( get_magic_quotes_gpc() ) { $value = stripslashes( $value ); } else { $value = addslashes( $value ); } if( function_exists( "mysql_real_escape_string" ) ) { $value = mysql_real_escape_string( $value ); } return $value; } function clean($str) { $str = strip_tags($str, '<br>,<br />'); $str = trim($str); $str = sql_quote($str); return $str; } foreach ($_POST as &$value) { if (!is_array($value)) { $value = clean($value); } else { clean($value); } } foreach ($_GET as &$value) { if (!is_array($value)) { $value = clean($value); } else { clean($value); } } function validate_name( $fld, $min, $max, $rule, $label ) { if( $rule == 'required' ) { if ( trim($fld) == '' ) { $str = "$label: Cannot be left blank."; return $str; } } if ( isset($fld) && trim($fld) != '' ) { if ( isset($fld) && $fld != '' && !preg_match("/^[a-zA-Z\ ]+$/", $fld)) { $str = "$label: Invalid characters used! Only Lowercase, Uppercase alphabets and Spaces are allowed"; } else if ( strlen($fld) < $min or strlen($fld) > $max ) { $curr_char = strlen($fld); $str = "$label: Must be atleast $min character &amp; less than $max char. Entered characters: $curr_char"; } else { $str = 0; } } else { $str = 0; } return $str; } function validate_email( $fld, $min, $max, $rule, $label ) { if( $rule == 'required' ) { if ( trim($fld) == '' ) { $str = "$label: Cannot be left blank."; return $str; } } if ( isset($fld) && trim($fld) != '' ) { if ( !eregi('^[a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\.([a-zA-Z]{2,4})$', $fld) ) { $str = "$label: Invalid format. Please check."; } else if ( strlen($fld) < $min or strlen($fld) > $max ) { $curr_char = strlen($fld); $str = "$label: Must be atleast $min character &amp; less than $max char. Entered characters: $curr_char"; } else { $str = 0; } } else { $str = 0; } return $str; } function val_rules( $str, $val_type, $rule='required' ){ switch ($val_type) { case 'name': $val = validate_name( $str, 3, 20, $rule, 'First Name'); break; case 'lname': $val = validate_name( $str, 10, 20, $rule, 'Last Name'); break; case 'email': $val = validate_email( $str, 10, 60, $rule, 'Email'); break; } return $val; } function fn_register() { $errors = array(); $val_name = val_rules( $_POST['name'], 'name' ); $val_lname = val_rules( $_POST['lname'], 'lname', 'optional' ); $val_email = val_rules( $_POST['email'], 'email' ); if ( $val_name != '0' ) { $errors['name'] = $val_name; } if ( $val_lname != '0' ) { $errors['lname'] = $val_lname; } if ( $val_email != '0' ) { $errors['email'] = $val_email; } return $errors; } //END of functions.php page ?> OK, now it might look like there's a lot, but lemme break it down target wise: 1. I wanted the foreach ($_POST as &$value) and foreach ($_GET as &$value) loops to loop through the received info from the user submission and strip/remove all malicious input. I am calling a function called clean on the input first to achieve the objective as stated above. This function will process each of the input, whether individual field values or even arrays and allow only tags and remove everything else. The rest of it is obvious. Once this happens, the new/cleaned values will be processed by the fn_register() function and based on the values returned after the validation, we get the corresponding errors or NULL values (as applicable). So here's my questions: 1. This pretty much makes me feel secure as I am forcing the user to correct malicious data and won't process the final data unless the errors are corrected. Am I correct? Does the method that I follow guarantee the speed (as I am using lots of functions and their corresponding calls)? The fields of a form differ and the minimum number of fields I may have at any given point of time in any form may be 3 and can go upto as high as 100 (or even more, I am not sure as the website is still being developed). Will having 100's of fields and their validation in the above way, reduce the speed of application (say upto half a million users are accessing the website at the same time?). What can I do to improve the speed and reduce function calls (if possible)? 3, Can I do something to improve the current ways of validation? I am holding off object oriented approach and using FILTERS in PHP for the later. So please, I request you all to suggest me way to improve/tweak the current ways and suggest me if the script is vulnerable or safe enough to be used in a Live production environment. If not, what I can do to be able to use it live? Thank you all in advance.

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  • What arguments do I send a function being called by a button in python?

    - by Jared
    I have a UI, in that UI is 4 text fields and 1 int field, then I have a function that calls to another function based on what's inside of the text fields, this function has (self, *args). My function that is being called to takes five arguments and I don't know what to put in it to make it actually work with my UI because python button's send an argument of their own. I have tried self and *args, but it doesn't work. Here is my code, didn't include most of the UI code since it is self explanatory: def crBC(self, IKJoint, FKJoint, bindJoint, xQuan, switch): ''' You should have a controller with an attribute 'ikFkBlend' - The name can be changed after the script executes. Controller should contain an enum - FK/DYN(0), IK(1). Specify the IK joint, then either the dynamic or FK joint, then the bind joint. Then a quantity of joints to pass through and connect. Tested currently on 600 joints (200 x 3), executed in less than a second. Returns nothing. Please open your script editor for details. ''' import itertools # gets children joints of the selected joint chHipIK = cmds.listRelatives(IKJoint, ad = True, type = 'joint') chHipFK = cmds.listRelatives(FKJoint, ad = True, type = 'joint') chHipBind = cmds.listRelatives(bindJoint, ad = True, type = 'joint') # list is built backwards, this reverses the list chHipIK.reverse() chHipFK.reverse() chHipBind.reverse() # appends the initial joint to the list chHipIK.append(IKJoint) chHipFK.append(FKJoint) chHipBind.append(bindJoint) # puts the last joint at the start of the list because the initial joint # was added to the end chHipIK.insert(0, chHipIK.pop()) chHipFK.insert(0, chHipFK.pop()) chHipBind.insert(0, chHipBind.pop()) # pops off the remaining joints in the list the user does not wish to be blended chHipBind[xQuan:] = [] chHipIK[xQuan:] = [] chHipFK[xQuan:] = [] # goes through the bind joints, makes a blend colors for each one, connects # the switch to the blender for a, b, c in itertools.izip(chHipBind, chHipIK, chHipFK): rotBC = cmds.shadingNode('blendColors', asUtility = True, n = a + 'rotate_BC') tranBC = cmds.shadingNode('blendColors', asUtility = True, n = a + 'tran_BC') scaleBC = cmds.shadingNode('blendColors', asUtility = True, n = a + 'scale_BC') cmds.connectAttr(switch + '.ikFkSwitch', rotBC + '.blender') cmds.connectAttr(switch + '.ikFkSwitch', tranBC + '.blender') cmds.connectAttr(switch + '.ikFkSwitch', scaleBC + '.blender') # goes through the ik joints, connects to the blend colors cmds.connectAttr(b + '.rotate', rotBC + '.color1', force = True) cmds.connectAttr(b + '.translate', tranBC + '.color1', force = True) cmds.connectAttr(b + '.scale', scaleBC + '.color1', force = True) # connects FK joints to the blend colors cmds.connectAttr(c + '.rotate', rotBC + '.color2') cmds.connectAttr(c + '.translate', tranBC + '.color2') cmds.connectAttr(c + '.scale', scaleBC + '.color2') # connects blend colors to bind joints cmds.connectAttr(rotBC + '.output', a + '.rotate') cmds.connectAttr(tranBC + '.output', a + '.translate') cmds.connectAttr(scaleBC + '.output', a + '.scale') ------------------- def execCrBC(self, *args): g.crBC(cmds.textField(self.ikJBC, q = True, tx = True), cmds.textField(self.fkJBC, q = True, tx = True), cmds.textField(self.bindJBC, q = True, tx = True), cmds.intField(self.bQBC, q = True, v = True), cmds.textField(self.sCBC, q = True, tx = True)) ------------------- self.bQBC = cmds.intField() cmds.text(l = '') self.sCBC = cmds.textField() cmds.text(l = '') cmds.button(l = 'Help Docs', c = self.crBC.__doc__) cmds.setParent('..') cmds.button(l = 'Create', c = self.execCrBC) Here is the code causing the problem as requested: import maya.cmds as cmds import jtRigUI.createDummyRig as dum import jtRigUI.createSkeleton as sk import jtRigUI.generalUtilities as gu import jtRigUI.createLegRig as lr import jtRigUI.createArmRig as ar class RUI(dum.Dict, dum.Dummy, sk.Skel, sk.FiSkel, lr.LeanLocs, lr.LegRig, ar.ArmRig, gu.Gutils): def __init__(self, charNameUI, gScaleUI, fingButtonGrp, thumbCheckBox, spineButtonGrp, neckButtonGrp, ikJBC, fkJBC, bindJBC, bQBC, sCBC): rigUI = 'rigUI' if cmds.window(rigUI, exists = True): cmds.deleteUI(rigUI) rigUI = cmds.window(rigUI, t = 'JT Rigging UI', sizeable = False, tb = True, mnb = False, mxb = False, menuBar = True, tlb = True, nm = 5) form = cmds.formLayout() tabs = cmds.tabLayout(innerMarginWidth = 1, innerMarginHeight = 1) rigUIMenu = cmds.menu('Help', hm = True) aboutMenu = cmds.menuItem('about') cmds.popupMenu('about', button = 1) deleteUIMenu = cmds.menu('Delete', hm = True) cmds.menuItem('dummySkeleton') cmds.formLayout(form, edit = True, attachForm = ((tabs, 'top', 0), (tabs, 'left', 0), (tabs, 'bottom', 0), (tabs, 'right', 0)), w = 30) tab1 = cmds.rowColumnLayout('Dummy') #cmds.columnLayout(rowSpacing = 10) #cmds.setParent('..') cmds.frameLayout(l = 'A: Dummy Skeleton Setup', w = 400) self.charNameUI = cmds.textFieldGrp (label="Optional Character Name:", ann="Insert a name for the character or leave empty.", tx = '', w = 1) fingJUI = cmds.frameLayout(l = 'B: Number of Fingers', w = 10) cmds.text('\n', h = 5) self.fingButtonGrp = cmds.radioButtonGrp('fingRadio', p = fingJUI, l = 'Fingers: ', sl = 4, w = 1, numberOfRadioButtons = 4, labelArray4 = ['One', 'Two', 'Three', 'Four'], ct2 = ('left', 'left'), cw5 = [60,60,60,60,60]) self.thumbCheckBox = cmds.checkBoxGrp(l = 'Thumb: ', v1 = True) cmds.text('\n', h = 5) spineJUI = cmds.frameLayout(l = 'C: Number of Spine Joints') cmds.text('\n', h = 5) self.spineButtonGrp = cmds.radioButtonGrp('spineRadio', p = spineJUI, l = 'Spine Joints: ', sl = 2, w = 1, numberOfRadioButtons = 3, labelArray3 = ['Three', 'Five', 'Ten'], ct2 = ('left', 'left'), cw4 = [95,95,95,95]) cmds.text('\n', h = 5) neckJUI = cmds.frameLayout(l = 'D: Number of Neck Joints') cmds.text('\n', h = 5) self.neckButtonGrp = cmds.radioButtonGrp('neckRadio', p = neckJUI, l = 'Neck Joints: ', sl = 0, w = 1, numberOfRadioButtons = 3, labelArray3 = ['Two', 'Three', 'Four'], ct2 = ('left', 'left'), cw4 = [95,95,95,95]) cmds.text('\n', h = 5) cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') cmds.frameLayout('E: Creation') cmds.text('SAVE FIRST: CAN NOT UNDO', bgc = (0.2,0.2,0.2)) cmds.button(l = '\nCreate Dummy Skeleton\n', c = self.build) # also have it make char name field grey cmds.text('Elbows and Knees must have bend.', bgc = (0.2,0.2,0.2)) cmds.columnLayout() cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') tab2 = cmds.rowColumnLayout('Skeleton') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'A: Skeleton Setup') cmds.text('SAVE FIRST: CAN NOT UNDO', bgc = (0.2,0.2,0.2)) cmds.button(l = '\nConvert to Skeleton - Orient - Set LRA\n', c = self.buildSkel) self.gScaleUI = cmds.textFieldGrp (label="Scale Multiplier:", ann="Scale multipler of Character: basis for all further base controllers", tx = '1.0', w = 1, ed = False, en = False, visible = True) cmds.frameLayout('B: Manual Orientation') cmds.text('You must manually check finger, thumb, leg, foot orientation specifically.\nConfirm rest of joints.\nSpine: X aim, Y point backwards from spine, Z to the side.\nFingers: X is aim, Y points upwards, Z to the side - Spread on Y, curl on Z.\nFoot: Pivots on Y, rolls on Z, leans on X.') cmds.columnLayout() cmds.setParent('..') cmds.frameLayout('C: Finalize Creation of Skeleton') cmds.button(l = '\nFinalize Skeleton\n', c = self.finishS) cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') tab3 = cmds.rowColumnLayout('Legs') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'A: Leg Rig Setup') cmds.button(l = '\nGenerate Foot Lean Locators\n', c = self.makeLean) cmds.text('Place on either side of the foot.\nDo not rotate: Automatic orientation in place.') cmds.frameLayout(l = 'B: Rig Legs') cmds.button(l = '\nRig Legs\n', c = self.makeLegs) cmds.setParent('..') cmds.setParent('..') cmds.setParent('..') tab4 = cmds.rowColumnLayout('Arms') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'A: Arm Rig Setup') cmds.button(l = '\nA: Rig Arms\n', c = self.makeArms) cmds.setParent('..') cmds.setParent('..') tab5 = cmds.rowColumnLayout('Spine and Head') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'Spine Rig Setup') cmds.setParent('..') cmds.setParent('..') tab6 = cmds.rowColumnLayout('Stretchy IK') cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'Stretchy Setup') cmds.setParent('..') cmds.setParent('..') tab6 = cmds.rowColumnLayout('Extras') cmds.scrollLayout(saw = 600, sah = 600, cr = True) cmds.columnLayout(columnAttach = ('both', 5), rowSpacing = 10, columnWidth = 150) cmds.setParent('..') cmds.frameLayout(l = 'General Utitlities') cmds.text('\nHere are all my general utilities for various things') cmds.frameLayout(l = 'Automatic Blend Colors Creation and Connection') cmds.rowColumnLayout(nc = 5, w = 10) cmds.text('IK Joint:') cmds.text(l = '') cmds.text('FK/Dyn Joint:') cmds.text(l = '') cmds.text('Bind Joint:') self.ikJBC = cmds.textField() cmds.text(l = '') self.fkJBC = cmds.textField() cmds.text(l = '') self.bindJBC = cmds.textField() cmds.text(' \nBlend Quantity:') cmds.text(l = '') cmds.text(' \nSwitch Control:') cmds.text(l = '') cmds.text(l = '') self.bQBC = cmds.intField() cmds.text(l = '') self.sCBC = cmds.textField() cmds.text(l = '') cmds.button(l = 'Help Docs', c = self.crBC.__doc__) cmds.setParent('..') cmds.button(l = 'Create', c = self.execCrBC) cmds.text(l = '') cmds.setParent('..') cmds.frameLayout(l = 'Make Spline IK Curve Stretch And Squash') cmds.rowColumnLayout(nc = 5, w = 10) cmds.text('Curve Name:') cmds.text(l = '') cmds.text('Setup Name:') cmds.text(l = '') cmds.text('Joint Quantity:') self.ikJBC = cmds.textField() cmds.text(l = '') self.fkJBC = cmds.textField() cmds.text(l = '') self.bindJBC = cmds.textField() cmds.text(' \nSwitch Control:') cmds.text(l = '') cmds.text(' \nGlobal Control:') cmds.text(l = '') cmds.text(l = '') self.bQBC = cmds.intField() cmds.text(l = '') self.sCBC = cmds.textField() cmds.text(l = '') cmds.button(l = 'Help Docs', c = self.crBC.__doc__) cmds.setParent('..') cmds.button(l = 'Create', c = self.execCrBC) cmds.setParent('..') cmds.showWindow(rigUI) r = RUI('charNameUI', 'gScaleUI', 'fingButtonGrp', 'thumbCheckBox', 'spineButtonGrp', 'neckButtonGrp', 'ikJBC', 'fkJBC', 'bindJBC', 'bQBC', 'sCBC') # last modified at 6.20 pm 29th June 2011

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  • XSD and plain text

    - by Paul Knopf
    I have a rest/xml service that gives me the following... <verse-unit unit-id="38009001"> <marker class="begin-verse" mid="v38009001"/> <begin-chapter num="9"/><heading>Judgment on Israel&apos;s Enemies</heading> <begin-block-indent/> <begin-paragraph class="line-group"/> <begin-line/><verse-num begin-chapter="9">1</verse-num>The burden of the word of the <span class="divine-name">Lord</span> is against the land of Hadrach<end-line class="br"/> <begin-line class="indent"/>and Damascus is its resting place.<end-line class="br"/> <begin-line/>For the <span class="divine-name">Lord</span> has an eye on mankind<end-line class="br"/> <begin-line class="indent"/>and on all the tribes of Israel,<footnote id="f1"> A slight emendation yields <i> For to the <span class="divine-name">Lord</span> belongs the capital of Syria and all the tribes of Israel </i> </footnote><end-line class="br"/> </verse-unit> I used visual studio to generate a schema from this and used XSD.EXE to generate classes that I can use to deserialize this mess into programmable stuff. I got everything to work and it is deserialized perfectly (almost). The problem I have is with the random text mixed throughout the child nodes. The generated verse-unit objects gives me a list of objects (begin-line, begin-block-indent, etc), and also another list of string objects that represent the bits of string throughout the xml. Here is my schema <xs:element maxOccurs="unbounded" name="verse-unit"> <xs:complexType mixed="true"> <xs:sequence> <xs:choice maxOccurs="unbounded"> <xs:element name="marker"> <xs:complexType> <xs:attribute name="class" type="xs:string" use="required" /> <xs:attribute name="mid" type="xs:string" use="required" /> </xs:complexType> </xs:element> <xs:element name="begin-chapter"> <xs:complexType> <xs:attribute name="num" type="xs:unsignedByte" use="required" /> </xs:complexType> </xs:element> <xs:element name="heading"> <xs:complexType mixed="true"> <xs:sequence minOccurs="0"> <xs:element name="span"> <xs:complexType> <xs:simpleContent> <xs:extension base="xs:string"> <xs:attribute name="class" type="xs:string" use="required" /> </xs:extension> </xs:simpleContent> </xs:complexType> </xs:element> </xs:sequence> </xs:complexType> </xs:element> <xs:element name="begin-block-indent" /> <xs:element name="begin-paragraph"> <xs:complexType> <xs:attribute name="class" type="xs:string" use="required" /> </xs:complexType> </xs:element> <xs:element name="begin-line"> <xs:complexType> <xs:attribute name="class" type="xs:string" use="optional" /> </xs:complexType> </xs:element> <xs:element name="verse-num"> <xs:complexType> <xs:simpleContent> <xs:extension base="xs:unsignedByte"> <xs:attribute name="begin-chapter" type="xs:unsignedByte" use="optional" /> </xs:extension> </xs:simpleContent> </xs:complexType> </xs:element> <xs:element name="end-line"> <xs:complexType> <xs:attribute name="class" type="xs:string" use="optional" /> </xs:complexType> </xs:element> <xs:element name="end-paragraph" /> <xs:element name="end-block-indent" /> <xs:element name="end-chapter" /> </xs:choice> </xs:sequence> <xs:attribute name="unit-id" type="xs:unsignedInt" use="required" /> </xs:complexType> </xs:element> WHAT I NEED IS THIS. I need the random text that is NOT surrounded by an xml node to be represented by an object so I know the order that everything is in. I know this is complicated, so let me try to simplify it. <field name="test_field_0"> Some text I'm sure you don't want. <subfield>Some text.</subfield> More text you don't want. </field> I need the xsd to generate a field object with items that can have either a text object, or a subfield object. I need to no where the random text is within the child nodes.

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  • Trouble passing a template function as an argument to another function in C++

    - by Darel
    Source of the problem -Accelerated C++, problem 8-5 I've written a small program that examines lines of string input, and tallies the number of times a word appears on a given line. The following code accomplishes this: #include <map> #include <iostream> #include <string> #include <vector> #include <list> #include <cctype> #include <iterator> using std::vector; using std::string; using std::cin; using std::cout; using std::endl; using std::getline; using std::istream; using std::string; using std::list; using std::map; using std::isspace; using std::ostream_iterator; using std::allocator; inline void keep_window_open() { cin.clear(); cout << "Please enter EOF to exit\n"; char ch; cin >> ch; return; } template <class Out> void split(const string& s, Out os) { vector<string> ret; typedef string::size_type string_size; string_size i = 0; // invariant: we have processed characters `['original value of `i', `i)' while (i != s.size()) { // ignore leading blanks // invariant: characters in range `['original `i', current `i)' are all spaces while (i != s.size() && isspace(s[i])) ++i; // find end of next word string_size j = i; // invariant: none of the characters in range `['original `j', current `j)' is a space while (j != s.size() && !isspace(s[j])) ++j; // if we found some nonwhitespace characters if (i != j) { // copy from `s' starting at `i' and taking `j' `\-' `i' chars *os++ = (s.substr(i, j - i)); i = j; } } } // find all the lines that refer to each word in the input map<string, vector<int> > xref(istream& in) // works // now try to pass the template function as an argument to function - what do i put for templated type? //map<string, vector<int> > xref(istream& in, void find_words(vector<string, typedef Out) = split) #LINE 1# { string line; int line_number = 0; map<string, vector<int> > ret; // read the next line while (getline(in, line)) { ++line_number; // break the input line into words vector<string> words; // works // #LINE 2# split(line, back_inserter(words)); // #LINE 3# //find_words(line, back_inserter(words)); // #LINE 4# attempting to use find_words as an argument to function // remember that each word occurs on the current line for (vector<string>::const_iterator it = words.begin(); it != words.end(); ++it) ret[*it].push_back(line_number); } return ret; } int main() { cout << endl << "Enter lines of text, followed by EOF (^Z):" << endl; // call `xref' using `split' by default map<string, vector<int> > ret = xref(cin); // write the results for (map<string, vector<int> >::const_iterator it = ret.begin(); it != ret.end(); ++it) { // write the word cout << it->first << " occurs on line(s): "; // followed by one or more line numbers vector<int>::const_iterator line_it = it->second.begin(); cout << *line_it; // write the first line number ++line_it; // write the rest of the line numbers, if any while (line_it != it->second.end()) { cout << ", " << *line_it; ++line_it; } // write a new line to separate each word from the next cout << endl; } keep_window_open(); return 0; } As you can see, the split function is a template function to handle various types of output iterators as desired. My problem comes when I try to generalize the xref function by passing in the templated split function as an argument. I can't seem to get the type correct. So my question is, can you pass a template function to another function as an argument, and if so, do you have to declare all types before passing it? Or can the compiler infer the types from the way the templated function is used in the body? To demonstrate the errors I get, comment out the existing xref function header, and uncomment the alternate header I'm trying to get working (just below the following commment line.) Also comment the lines tagged LINE 2 and LINE 3 and uncomment LINE 4, which is attempting to use the argument find_words (which defaults to split.) Thanks for any feedback!

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  • Problems with real-valued input deep belief networks (of RBMs)

    - by Junier
    I am trying to recreate the results reported in Reducing the dimensionality of data with neural networks of autoencoding the olivetti face dataset with an adapted version of the MNIST digits matlab code, but am having some difficulty. It seems that no matter how much tweaking I do on the number of epochs, rates, or momentum the stacked RBMs are entering the fine-tuning stage with a large amount of error and consequently fail to improve much at the fine-tuning stage. I am also experiencing a similar problem on another real-valued dataset. For the first layer I am using a RBM with a smaller learning rate (as described in the paper) and with negdata = poshidstates*vishid' + repmat(visbiases,numcases,1); I'm fairly confident I am following the instructions found in the supporting material but I cannot achieve the correct errors. Is there something I am missing? See the code I'm using for real-valued visible unit RBMs below, and for the whole deep training. The rest of the code can be found here. rbmvislinear.m: epsilonw = 0.001; % Learning rate for weights epsilonvb = 0.001; % Learning rate for biases of visible units epsilonhb = 0.001; % Learning rate for biases of hidden units weightcost = 0.0002; initialmomentum = 0.5; finalmomentum = 0.9; [numcases numdims numbatches]=size(batchdata); if restart ==1, restart=0; epoch=1; % Initializing symmetric weights and biases. vishid = 0.1*randn(numdims, numhid); hidbiases = zeros(1,numhid); visbiases = zeros(1,numdims); poshidprobs = zeros(numcases,numhid); neghidprobs = zeros(numcases,numhid); posprods = zeros(numdims,numhid); negprods = zeros(numdims,numhid); vishidinc = zeros(numdims,numhid); hidbiasinc = zeros(1,numhid); visbiasinc = zeros(1,numdims); sigmainc = zeros(1,numhid); batchposhidprobs=zeros(numcases,numhid,numbatches); end for epoch = epoch:maxepoch, fprintf(1,'epoch %d\r',epoch); errsum=0; for batch = 1:numbatches, if (mod(batch,100)==0) fprintf(1,' %d ',batch); end %%%%%%%%% START POSITIVE PHASE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% data = batchdata(:,:,batch); poshidprobs = 1./(1 + exp(-data*vishid - repmat(hidbiases,numcases,1))); batchposhidprobs(:,:,batch)=poshidprobs; posprods = data' * poshidprobs; poshidact = sum(poshidprobs); posvisact = sum(data); %%%%%%%%% END OF POSITIVE PHASE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% poshidstates = poshidprobs > rand(numcases,numhid); %%%%%%%%% START NEGATIVE PHASE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% negdata = poshidstates*vishid' + repmat(visbiases,numcases,1);% + randn(numcases,numdims) if not using mean neghidprobs = 1./(1 + exp(-negdata*vishid - repmat(hidbiases,numcases,1))); negprods = negdata'*neghidprobs; neghidact = sum(neghidprobs); negvisact = sum(negdata); %%%%%%%%% END OF NEGATIVE PHASE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% err= sum(sum( (data-negdata).^2 )); errsum = err + errsum; if epoch>5, momentum=finalmomentum; else momentum=initialmomentum; end; %%%%%%%%% UPDATE WEIGHTS AND BIASES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% vishidinc = momentum*vishidinc + ... epsilonw*( (posprods-negprods)/numcases - weightcost*vishid); visbiasinc = momentum*visbiasinc + (epsilonvb/numcases)*(posvisact-negvisact); hidbiasinc = momentum*hidbiasinc + (epsilonhb/numcases)*(poshidact-neghidact); vishid = vishid + vishidinc; visbiases = visbiases + visbiasinc; hidbiases = hidbiases + hidbiasinc; %%%%%%%%%%%%%%%% END OF UPDATES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% end fprintf(1, '\nepoch %4i error %f \n', epoch, errsum); end dofacedeepauto.m: clear all close all maxepoch=200; %In the Science paper we use maxepoch=50, but it works just fine. numhid=2000; numpen=1000; numpen2=500; numopen=30; fprintf(1,'Pretraining a deep autoencoder. \n'); fprintf(1,'The Science paper used 50 epochs. This uses %3i \n', maxepoch); load fdata %makeFaceData; [numcases numdims numbatches]=size(batchdata); fprintf(1,'Pretraining Layer 1 with RBM: %d-%d \n',numdims,numhid); restart=1; rbmvislinear; hidrecbiases=hidbiases; save mnistvh vishid hidrecbiases visbiases; maxepoch=50; fprintf(1,'\nPretraining Layer 2 with RBM: %d-%d \n',numhid,numpen); batchdata=batchposhidprobs; numhid=numpen; restart=1; rbm; hidpen=vishid; penrecbiases=hidbiases; hidgenbiases=visbiases; save mnisthp hidpen penrecbiases hidgenbiases; fprintf(1,'\nPretraining Layer 3 with RBM: %d-%d \n',numpen,numpen2); batchdata=batchposhidprobs; numhid=numpen2; restart=1; rbm; hidpen2=vishid; penrecbiases2=hidbiases; hidgenbiases2=visbiases; save mnisthp2 hidpen2 penrecbiases2 hidgenbiases2; fprintf(1,'\nPretraining Layer 4 with RBM: %d-%d \n',numpen2,numopen); batchdata=batchposhidprobs; numhid=numopen; restart=1; rbmhidlinear; hidtop=vishid; toprecbiases=hidbiases; topgenbiases=visbiases; save mnistpo hidtop toprecbiases topgenbiases; backpropface; Thanks for your time

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  • Need help with copy constructor for very basic implementation of singly linked lists

    - by Jesus
    Last week, we created a program that manages sets of strings, using classes and vectors. I was able to complete this 100%. This week, we have to replace the vector we used to store strings in our class with simple singly linked lists. The function basically allows users to declare sets of strings that are empty, and sets with only one element. In the main file, there is a vector whose elements are a struct that contain setName and strSet (class). HERE IS MY PROBLEM: It deals with the copy constructor of the class. When I remove/comment out the copy constructor, I can declare as many empty or single sets as I want, and output their values without a problem. But I know I will obviously need the copy constructor for when I implement the rest of the program. When I leave the copy constructor in, I can declare one set, either single or empty, and output its value. But if I declare a 2nd set, and i try to output either of the first two sets, i get a Segmentation Fault. Moreover, if i try to declare more then 2 sets, I get a Segmentation Fault. Any help would be appreciated!! Here is my code for a very basic implementation of everything: Here is the setcalc.cpp: (main file) #include <iostream> #include <cctype> #include <cstring> #include <string> #include "help.h" #include "strset2.h" using namespace std; // Declares of structure to hold all the sets defined struct setsOfStr { string nameOfSet; strSet stringSet; }; // Checks if the set name inputted is unique bool isSetNameUnique( vector<setsOfStr> strSetArr, string setName) { for(unsigned int i = 0; i < strSetArr.size(); i++) { if( strSetArr[i].nameOfSet == setName ) { return false; } } return true; } int main(int argc, char *argv[]) { char commandChoice; // Declares a vector with our declared structure as the type vector<setsOfStr> strSetVec; string setName; string singleEle; // Sets a loop that will constantly ask for a command until 'q' is typed while (1) { // declaring a set to be empty if(commandChoice == 'd') { cin >> setName; // Check that the set name inputted is unique if (isSetNameUnique(strSetVec, setName) == true) { strSet emptyStrSet; setsOfStr set1; set1.nameOfSet = setName; set1.stringSet = emptyStrSet; strSetVec.push_back(set1); } else { cerr << "ERROR: Re-declaration of set '" << setName << "'\n"; } } // declaring a set to be a singleton else if(commandChoice == 's') { cin >> setName; cin >> singleEle; // Check that the set name inputted is unique if (isSetNameUnique(strSetVec, setName) == true) { strSet singleStrSet(singleEle); setsOfStr set2; set2.nameOfSet = setName; set2.stringSet = singleStrSet; strSetVec.push_back(set2); } else { cerr << "ERROR: Re-declaration of set '" << setName << "'\n"; } } // using the output function else if(commandChoice == 'o') { cin >> setName; if(isSetNameUnique(strSetVec, setName) == false) { // loop through until the set name is matched and call output on its strSet for(unsigned int k = 0; k < strSetVec.size(); k++) { if( strSetVec[k].nameOfSet == setName ) { (strSetVec[k].stringSet).output(); } } } else { cerr << "ERROR: No such set '" << setName << "'\n"; } } // quitting else if(commandChoice == 'q') { break; } else { cerr << "ERROR: Ignoring bad command: '" << commandChoice << "'\n"; } } return 0; } Here is the strSet2.h: #ifndef _STRSET_ #define _STRSET_ #include <iostream> #include <vector> #include <string> struct node { std::string s1; node * next; }; class strSet { private: node * first; public: strSet (); // Create empty set strSet (std::string s); // Create singleton set strSet (const strSet &copy); // Copy constructor // will implement destructor later void output() const; strSet& operator = (const strSet& rtSide); // Assignment }; // End of strSet class #endif // _STRSET_ And here is the strSet2.cpp (implementation of class) #include <iostream> #include <vector> #include <string> #include "strset2.h" using namespace std; strSet::strSet() { first = NULL; } strSet::strSet(string s) { node *temp; temp = new node; temp->s1 = s; temp->next = NULL; first = temp; } strSet::strSet(const strSet& copy) { cout << "copy-cst\n"; node *n = copy.first; node *prev = NULL; while (n) { node *newNode = new node; newNode->s1 = n->s1; newNode->next = NULL; if (prev) { prev->next = newNode; } else { first = newNode; } prev = newNode; n = n->next; } } void strSet::output() const { if(first == NULL) { cout << "Empty set\n"; } else { node *temp; temp = first; while(1) { cout << temp->s1 << endl; if(temp->next == NULL) break; temp = temp->next; } } } strSet& strSet::operator = (const strSet& rtSide) { first = rtSide.first; return *this; }

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  • Problems with real-valued deep belief networks (of RBMs)

    - by Junier
    I am trying to recreate the results reported in Reducing the dimensionality of data with neural networks of autoencoding the olivetti face dataset with an adapted version of the MNIST digits matlab code, but am having some difficulty. It seems that no matter how much tweaking I do on the number of epochs, rates, or momentum the stacked RBMs are entering the fine-tuning stage with a large amount of error and consequently fail to improve much at the fine-tuning stage. I am also experiencing a similar problem on another real-valued dataset. For the first layer I am using a RBM with a smaller learning rate (as described in the paper) and with negdata = poshidstates*vishid' + repmat(visbiases,numcases,1); I'm fairly confident I am following the instructions found in the supporting material but I cannot achieve the correct errors. Is there something I am missing? See the code I'm using for real-valued visible unit RBMs below, and for the whole deep training. The rest of the code can be found here. rbmvislinear.m: epsilonw = 0.001; % Learning rate for weights epsilonvb = 0.001; % Learning rate for biases of visible units epsilonhb = 0.001; % Learning rate for biases of hidden units weightcost = 0.0002; initialmomentum = 0.5; finalmomentum = 0.9; [numcases numdims numbatches]=size(batchdata); if restart ==1, restart=0; epoch=1; % Initializing symmetric weights and biases. vishid = 0.1*randn(numdims, numhid); hidbiases = zeros(1,numhid); visbiases = zeros(1,numdims); poshidprobs = zeros(numcases,numhid); neghidprobs = zeros(numcases,numhid); posprods = zeros(numdims,numhid); negprods = zeros(numdims,numhid); vishidinc = zeros(numdims,numhid); hidbiasinc = zeros(1,numhid); visbiasinc = zeros(1,numdims); sigmainc = zeros(1,numhid); batchposhidprobs=zeros(numcases,numhid,numbatches); end for epoch = epoch:maxepoch, fprintf(1,'epoch %d\r',epoch); errsum=0; for batch = 1:numbatches, if (mod(batch,100)==0) fprintf(1,' %d ',batch); end %%%%%%%%% START POSITIVE PHASE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% data = batchdata(:,:,batch); poshidprobs = 1./(1 + exp(-data*vishid - repmat(hidbiases,numcases,1))); batchposhidprobs(:,:,batch)=poshidprobs; posprods = data' * poshidprobs; poshidact = sum(poshidprobs); posvisact = sum(data); %%%%%%%%% END OF POSITIVE PHASE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% poshidstates = poshidprobs > rand(numcases,numhid); %%%%%%%%% START NEGATIVE PHASE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% negdata = poshidstates*vishid' + repmat(visbiases,numcases,1);% + randn(numcases,numdims) if not using mean neghidprobs = 1./(1 + exp(-negdata*vishid - repmat(hidbiases,numcases,1))); negprods = negdata'*neghidprobs; neghidact = sum(neghidprobs); negvisact = sum(negdata); %%%%%%%%% END OF NEGATIVE PHASE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% err= sum(sum( (data-negdata).^2 )); errsum = err + errsum; if epoch>5, momentum=finalmomentum; else momentum=initialmomentum; end; %%%%%%%%% UPDATE WEIGHTS AND BIASES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% vishidinc = momentum*vishidinc + ... epsilonw*( (posprods-negprods)/numcases - weightcost*vishid); visbiasinc = momentum*visbiasinc + (epsilonvb/numcases)*(posvisact-negvisact); hidbiasinc = momentum*hidbiasinc + (epsilonhb/numcases)*(poshidact-neghidact); vishid = vishid + vishidinc; visbiases = visbiases + visbiasinc; hidbiases = hidbiases + hidbiasinc; %%%%%%%%%%%%%%%% END OF UPDATES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% end fprintf(1, '\nepoch %4i error %f \n', epoch, errsum); end dofacedeepauto.m: clear all close all maxepoch=200; %In the Science paper we use maxepoch=50, but it works just fine. numhid=2000; numpen=1000; numpen2=500; numopen=30; fprintf(1,'Pretraining a deep autoencoder. \n'); fprintf(1,'The Science paper used 50 epochs. This uses %3i \n', maxepoch); load fdata %makeFaceData; [numcases numdims numbatches]=size(batchdata); fprintf(1,'Pretraining Layer 1 with RBM: %d-%d \n',numdims,numhid); restart=1; rbmvislinear; hidrecbiases=hidbiases; save mnistvh vishid hidrecbiases visbiases; maxepoch=50; fprintf(1,'\nPretraining Layer 2 with RBM: %d-%d \n',numhid,numpen); batchdata=batchposhidprobs; numhid=numpen; restart=1; rbm; hidpen=vishid; penrecbiases=hidbiases; hidgenbiases=visbiases; save mnisthp hidpen penrecbiases hidgenbiases; fprintf(1,'\nPretraining Layer 3 with RBM: %d-%d \n',numpen,numpen2); batchdata=batchposhidprobs; numhid=numpen2; restart=1; rbm; hidpen2=vishid; penrecbiases2=hidbiases; hidgenbiases2=visbiases; save mnisthp2 hidpen2 penrecbiases2 hidgenbiases2; fprintf(1,'\nPretraining Layer 4 with RBM: %d-%d \n',numpen2,numopen); batchdata=batchposhidprobs; numhid=numopen; restart=1; rbmhidlinear; hidtop=vishid; toprecbiases=hidbiases; topgenbiases=visbiases; save mnistpo hidtop toprecbiases topgenbiases; backpropface; Thanks for your time

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  • c# Unable to open file for reading

    - by Maks
    I'm writing a program that uses FileSystemWatcher to monitor changes to a given directory, and when it recieves OnCreated or OnChanged event, it copies those created/changed files to a specified directorie(s). At first I had problems with the fact that OnChanged/OnCreated events can be sent twice (not acceptable in case it needed to process 500MB file) but I made a way around this and with what I'm REALLY STUCKED with is getting the following IOException: The process cannot access the file 'C:\Where are Photos\bookmarks (11).html' because it is being used by another process. Thus, preventing the program from copying all the files it should. So as I mentioned, when user uses this program he/she specifes monitored directory, when user copies/creates/changes file in that directory, program should get OnCreated/OnChanged event and then copy that file to few other directories. Above error happens in all casess, if user copies few files that needs to owerwrite other ones in folder being monitored or when copying bulk of several files or even sometimes when copying one file in a monitored directory. Whole program is quite big so I'm sending the most important parts. OnCreated: private void OnCreated(object source, FileSystemEventArgs e) { AddLogEntry(e.FullPath, "created", ""); // Update last access data if it's file so the same file doesn't // get processed twice because of sending another event. if (fileType(e.FullPath) == 2) { lastPath = e.FullPath; lastTime = DateTime.Now; } // serves no purpose now, it will be remove soon string fileName = GetFileName(e.FullPath); // copies file from source to few other directories Copy(e.FullPath, fileName); Console.WriteLine("OnCreated: " + e.FullPath); } OnChanged: private void OnChanged(object source, FileSystemEventArgs e) { // is it directory if (fileType(e.FullPath) == 1) return; // don't mind directory changes itself // Only if enough time has passed or if it's some other file // because two events can be generated int timeDiff = ((TimeSpan)(DateTime.Now - lastTime)).Seconds; if ((timeDiff < minSecsDiff) && (e.FullPath.Equals(lastPath))) { Console.WriteLine("-- skipped -- {0}, timediff: {1}", e.FullPath, timeDiff); return; } // Update last access data for above to work lastPath = e.FullPath; lastTime = DateTime.Now; // Only if size is changed, the rest will handle other handlers if (e.ChangeType == WatcherChangeTypes.Changed) { AddLogEntry(e.FullPath, "changed", ""); string fileName = GetFileName(e.FullPath); Copy(e.FullPath, fileName); Console.WriteLine("OnChanged: " + e.FullPath); } } fileType: private int fileType(string path) { if (Directory.Exists(path)) return 1; // directory else if (File.Exists(path)) return 2; // file else return 0; } Copy: private void Copy(string srcPath, string fileName) { foreach (string dstDirectoy in paths) { string eventType = "copied"; string error = "noerror"; string path = ""; string dirPortion = ""; // in case directory needs to be made if (srcPath.Length > fsw.Path.Length) { path = srcPath.Substring(fsw.Path.Length, srcPath.Length - fsw.Path.Length); int pos = path.LastIndexOf('\\'); if (pos != -1) dirPortion = path.Substring(0, pos); } if (fileType(srcPath) == 1) { try { Directory.CreateDirectory(dstDirectoy + path); //Directory.CreateDirectory(dstDirectoy + fileName); eventType = "created"; } catch (IOException e) { eventType = "error"; error = e.Message; } } else { try { if (!overwriteFile && File.Exists(dstDirectoy + path)) continue; // create new dir anyway even if it exists just to be sure Directory.CreateDirectory(dstDirectoy + dirPortion); // copy file from where event occured to all specified directories using (FileStream fsin = new FileStream(srcPath, FileMode.Open, FileAccess.Read, FileShare.Read)) { using (FileStream fsout = new FileStream(dstDirectoy + path, FileMode.Create, FileAccess.Write)) { byte[] buffer = new byte[32768]; int bytesRead = -1; while ((bytesRead = fsin.Read(buffer, 0, buffer.Length)) > 0) fsout.Write(buffer, 0, bytesRead); } } } catch (Exception e) { if ((e is IOException) && (overwriteFile == false)) { eventType = "skipped"; } else { eventType = "error"; error = e.Message; // attempt to find and kill the process locking the file. // failed, miserably System.Diagnostics.Process tool = new System.Diagnostics.Process(); tool.StartInfo.FileName = "handle.exe"; tool.StartInfo.Arguments = "\"" + srcPath + "\""; tool.StartInfo.UseShellExecute = false; tool.StartInfo.RedirectStandardOutput = true; tool.Start(); tool.WaitForExit(); string outputTool = tool.StandardOutput.ReadToEnd(); string matchPattern = @"(?<=\s+pid:\s+)\b(\d+)\b(?=\s+)"; foreach (Match match in Regex.Matches(outputTool, matchPattern)) { System.Diagnostics.Process.GetProcessById(int.Parse(match.Value)).Kill(); } Console.WriteLine("ERROR: {0}: [ {1} ]", e.Message, srcPath); } } } AddLogEntry(dstDirectoy + path, eventType, error); } } I checked everywhere in my program and whenever I use some file I use it in using block so even writing event to log (class for what I ommited since there is probably too much code already in post) wont lock the file, that is it shouldn't since all operations are using using statement block. I simply have no clue who's locking the file if not my program "copy" process from user through Windows or something else. Right now I have two possible "solutions" (I can't say they are clean solutions since they are hacks and as such not desireable). Since probably the problem is with fileType method (what else could lock the file?) I tried changing it to this, to simulate "blocking-until-ready-to-open" operation: fileType: private int fileType(string path) { FileStream fs = null; int ret = 0; bool run = true; if (Directory.Exists(path)) ret = 1; else { while (run) { try { fs = new FileStream(path, FileMode.Open); ret = 2; run = false; } catch (IOException) { } finally { if (fs != null) { fs.Close(); fs.Dispose(); } } } } return ret; } This is working as much as I could tell (test), but... it's hack, not to mention other deficients. The other "solution" I could try (I didn't test it yet) is using GC.Collect() somewhere at the end of fileType() method. Maybe even worse "solution" than previous one. Can someone pleas tell me, what on earth is locking the file, preventing it from opening and how can I fix that? What am I missing to see? Thanks in advance.

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  • Building applications with WPF, MVVM and Prism(aka CAG)

    - by skjagini
    In this article I am going to walk through an application using WPF and Prism (aka composite application guidance, CAG) which simulates engaging a taxi (cab).  The rules are simple, the app would have3 screens A login screen to authenticate the user An information screen. A screen to engage the cab and roam around and calculating the total fare Metered Rate of Fare The meter is required to be engaged when a cab is occupied by anyone $3.00 upon entry $0.35 for each additional unit The unit fare is: one-fifth of a mile, when the cab is traveling at 6 miles an hour or more; or 60 seconds when not in motion or traveling at less than 12 miles per hour. Night surcharge of $.50 after 8:00 PM & before 6:00 AM Peak hour Weekday Surcharge of $1.00 Monday - Friday after 4:00 PM & before 8:00 PM New York State Tax Surcharge of $.50 per ride. Example: Friday (2010-10-08) 5:30pm Start at Lexington Ave & E 57th St End at Irving Pl & E 15th St Start = $3.00 Travels 2 miles at less than 6 mph for 15 minutes = $3.50 Travels at more than 12 mph for 5 minutes = $1.75 Peak hour Weekday Surcharge = $1.00 (ride started at 5:30 pm) New York State Tax Surcharge = $0.50 Before we dive into the app, I would like to give brief description about the framework.  If you want to jump on to the source code, scroll all the way to the end of the post. MVVM MVVM pattern is in no way related to the usage of PRISM in your application and should be considered if you are using WPF irrespective of PRISM or not. Lets say you are not familiar with MVVM, your typical UI would involve adding some UI controls like text boxes, a button, double clicking on the button,  generating event handler, calling a method from business layer and updating the user interface, it works most of the time for developing small scale applications. The problem with this approach is that there is some amount of code specific to business logic wrapped in UI specific code which is hard to unit test it, mock it and MVVM helps to solve the exact problem. MVVM stands for Model(M) – View(V) – ViewModel(VM),  based on the interactions with in the three parties it should be called VVMM,  MVVM sounds more like MVC (Model-View-Controller) so the name. Why it should be called VVMM: View – View Model - Model WPF allows to create user interfaces using XAML and MVVM takes it to the next level by allowing complete separation of user interface and business logic. In WPF each view will have a property, DataContext when set to an instance of a class (which happens to be your view model) provides the data the view is interested in, i.e., view interacts with view model and at the same time view model interacts with view through DataContext. Sujith, if view and view model are interacting directly with each other how does MVVM is helping me separation of concerns? Well, the catch is DataContext is of type Object, since it is of type object view doesn’t know exact type of view model allowing views and views models to be loosely coupled. View models aggregate data from models (data access layer, services, etc) and make it available for views through properties, methods etc, i.e., View Models interact with Models. PRISM Prism is provided by Microsoft Patterns and Practices team and it can be downloaded from codeplex for source code,  samples and documentation on msdn.  The name composite implies, to compose user interface from different modules (views) without direct dependencies on each other, again allowing  loosely coupled development. Well Sujith, I can already do that with user controls, why shall I learn another framework?  That’s correct, you can decouple using user controls, but you still have to manage some amount of coupling, like how to do you communicate between the controls, how do you subscribe/unsubscribe, loading/unloading views dynamically. Prism is not a replacement for user controls, provides the following features which greatly help in designing the composite applications. Dependency Injection (DI)/ Inversion of Control (IoC) Modules Regions Event Aggregator  Commands Simply put, MVVM helps building a single view and Prism helps building an application using the views There are other open source alternatives to Prism, like MVVMLight, Cinch, take a look at them as well. Lets dig into the source code.  1. Solution The solution is made of the following projects Framework: Holds the common functionality in building applications using WPF and Prism TaxiClient: Start up project, boot strapping and app styling TaxiCommon: Helps with the business logic TaxiModules: Holds the meat of the application with views and view models TaxiTests: To test the application 2. DI / IoC Dependency Injection (DI) as the name implies refers to injecting dependencies and Inversion of Control (IoC) means the calling code has no direct control on the dependencies, opposite of normal way of programming where dependencies are passed by caller, i.e inversion; aside from some differences in terminology the concept is same in both the cases. The idea behind DI/IoC pattern is to reduce the amount of direct coupling between different components of the application, the higher the dependency the more tightly coupled the application resulting in code which is hard to modify, unit test and mock.  Initializing Dependency Injection through BootStrapper TaxiClient is the starting project of the solution and App (App.xaml)  is the starting class that gets called when you run the application. From the App’s OnStartup method we will invoke BootStrapper.   namespace TaxiClient { /// <summary> /// Interaction logic for App.xaml /// </summary> public partial class App : Application { protected override void OnStartup(StartupEventArgs e) { base.OnStartup(e);   (new BootStrapper()).Run(); } } } BootStrapper is your contact point for initializing the application including dependency injection, creating Shell and other frameworks. We are going to use Unity for DI and there are lot of open source DI frameworks like Spring.Net, StructureMap etc with different feature set  and you can choose a framework based on your preferences. Note that Prism comes with in built support for Unity, for example we are deriving from UnityBootStrapper in our case and for any other DI framework you have to extend the Prism appropriately   namespace TaxiClient { public class BootStrapper: UnityBootstrapper { protected override IModuleCatalog CreateModuleCatalog() { return new ConfigurationModuleCatalog(); } protected override DependencyObject CreateShell() { Framework.FrameworkBootStrapper.Run(Container, Application.Current.Dispatcher);   Shell shell = new Shell(); shell.ResizeMode = ResizeMode.NoResize; shell.Show();   return shell; } } } Lets take a look into  FrameworkBootStrapper to check out how to register with unity container. namespace Framework { public class FrameworkBootStrapper { public static void Run(IUnityContainer container, Dispatcher dispatcher) { UIDispatcher uiDispatcher = new UIDispatcher(dispatcher); container.RegisterInstance<IDispatcherService>(uiDispatcher);   container.RegisterType<IInjectSingleViewService, InjectSingleViewService>( new ContainerControlledLifetimeManager());   . . . } } } In the above code we are registering two components with unity container. You shall observe that we are following two different approaches, RegisterInstance and RegisterType.  With RegisterInstance we are registering an existing instance and the same instance will be returned for every request made for IDispatcherService   and with RegisterType we are requesting unity container to create an instance for us when required, i.e., when I request for an instance for IInjectSingleViewService, unity will create/return an instance of InjectSingleViewService class and with RegisterType we can configure the life time of the instance being created. With ContaienrControllerLifetimeManager, the unity container caches the instance and reuses for any subsequent requests, without recreating a new instance. Lets take a look into FareViewModel.cs and it’s constructor. The constructor takes one parameter IEventAggregator and if you try to find all references in your solution for IEventAggregator, you will not find a single location where an instance of EventAggregator is passed directly to the constructor. The compiler still finds an instance and works fine because Prism is already configured when used with Unity container to return an instance of EventAggregator when requested for IEventAggregator and in this particular case it is called constructor injection. public class FareViewModel:ObservableBase, IDataErrorInfo { ... private IEventAggregator _eventAggregator;   public FareViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; InitializePropertyNames(); InitializeModel(); PropertyChanged += OnPropertyChanged; } ... 3. Shell Shells are very similar in operation to Master Pages in asp.net or MDI in Windows Forms. And shells contain regions which display the views, you can have as many regions as you wish in a given view. You can also nest regions. i.e, one region can load a view which in itself may contain other regions. We have to create a shell at the start of the application and are doing it by overriding CreateShell method from BootStrapper From the following Shell.xaml you shall notice that we have two content controls with Region names as ‘MenuRegion’ and ‘MainRegion’.  The idea here is that you can inject any user controls into the regions dynamically, i.e., a Menu User Control for MenuRegion and based on the user action you can load appropriate view into MainRegion.    <Window x:Class="TaxiClient.Shell" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Regions="clr-namespace:Microsoft.Practices.Prism.Regions;assembly=Microsoft.Practices.Prism" Title="Taxi" Height="370" Width="800"> <Grid Margin="2"> <ContentControl Regions:RegionManager.RegionName="MenuRegion" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" />   <ContentControl Grid.Row="1" Regions:RegionManager.RegionName="MainRegion" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" /> <!--<Border Grid.ColumnSpan="2" BorderThickness="2" CornerRadius="3" BorderBrush="LightBlue" />-->   </Grid> </Window> 4. Modules Prism provides the ability to build composite applications and modules play an important role in it. For example if you are building a Mortgage Loan Processor application with 3 components, i.e. customer’s credit history,  existing mortgages, new home/loan information; and consider that the customer’s credit history component involves gathering data about his/her address, background information, job details etc. The idea here using Prism modules is to separate the implementation of these 3 components into their own visual studio projects allowing to build components with no dependency on each other and independently. If we need to add another component to the application, the component can be developed by in house team or some other team in the organization by starting with a new Visual Studio project and adding to the solution at the run time with very little knowledge about the application. Prism modules are defined by implementing the IModule interface and each visual studio project to be considered as a module should implement the IModule interface.  From the BootStrapper.cs you shall observe that we are overriding the method by returning a ConfiguratingModuleCatalog which returns the modules that are registered for the application using the app.config file  and you can also add module using code. Lets take a look into configuration file.   <?xml version="1.0"?> <configuration> <configSections> <section name="modules" type="Microsoft.Practices.Prism.Modularity.ModulesConfigurationSection, Microsoft.Practices.Prism"/> </configSections> <modules> <module assemblyFile="TaxiModules.dll" moduleType="TaxiModules.ModuleInitializer, TaxiModules" moduleName="TaxiModules"/> </modules> </configuration> Here we are adding TaxiModules project to our solution and TaxiModules.ModuleInitializer implements IModule interface   5. Module Mapper With Prism modules you can dynamically add or remove modules from the regions, apart from that Prism also provides API to control adding/removing the views from a region within the same module. Taxi Information Screen: Engage the Taxi Screen: The sample application has two screens, ‘Taxi Information’ and ‘Engage the Taxi’ and they both reside in same module, TaxiModules. ‘Engage the Taxi’ is again made of two user controls, FareView on the left and TotalView on the right. We have created a Shell with two regions, MenuRegion and MainRegion with menu loaded into MenuRegion. We can create a wrapper user control called EngageTheTaxi made of FareView and TotalView and load either TaxiInfo or EngageTheTaxi into MainRegion based on the user action. Though it will work it tightly binds the user controls and for every combination of user controls, we need to create a dummy wrapper control to contain them. Instead we can apply the principles we learned so far from Shell/regions and introduce another template (LeftAndRightRegionView.xaml) made of two regions Region1 (left) and Region2 (right) and load  FareView and TotalView dynamically.  To help with loading of the views dynamically I have introduce an helper an interface, IInjectSingleViewService,  idea suggested by Mike Taulty, a must read blog for .Net developers. using System; using System.Collections.Generic; using System.ComponentModel;   namespace Framework.PresentationUtility.Navigation {   public interface IInjectSingleViewService : INotifyPropertyChanged { IEnumerable<CommandViewDefinition> Commands { get; } IEnumerable<ModuleViewDefinition> Modules { get; }   void RegisterViewForRegion(string commandName, string viewName, string regionName, Type viewType); void ClearViewFromRegion(string viewName, string regionName); void RegisterModule(string moduleName, IList<ModuleMapper> moduleMappers); } } The Interface declares three methods to work with views: RegisterViewForRegion: Registers a view with a particular region. You can register multiple views and their regions under one command.  When this particular command is invoked all the views registered under it will be loaded into their regions. ClearViewFromRegion: To unload a specific view from a region. RegisterModule: The idea is when a command is invoked you can load the UI with set of controls in their default position and based on the user interaction, you can load different contols in to different regions on the fly.  And it is supported ModuleViewDefinition and ModuleMappers as shown below. namespace Framework.PresentationUtility.Navigation { public class ModuleViewDefinition { public string ModuleName { get; set; } public IList<ModuleMapper> ModuleMappers; public ICommand Command { get; set; } }   public class ModuleMapper { public string ViewName { get; set; } public string RegionName { get; set; } public Type ViewType { get; set; } } } 6. Event Aggregator Prism event aggregator enables messaging between components as in Observable pattern, Notifier notifies the Observer which receives notification it is interested in. When it comes to Observable pattern, Observer has to unsubscribes for notifications when it no longer interested in notifications, which allows the Notifier to remove the Observer’s reference from it’s local cache. Though .Net has managed garbage collection it cannot remove inactive the instances referenced by an active instance resulting in memory leak, keeping the Observers in memory as long as Notifier stays in memory.  Developers have to be very careful to unsubscribe when necessary and it often gets overlooked, to overcome these problems Prism Event Aggregator uses weak references to cache the reference (Observer in this case)  and releases the reference (memory) once the instance goes out of scope. Using event aggregator is very simple, declare a generic type of CompositePresenationEvent by inheriting from it. using Microsoft.Practices.Prism.Events; using TaxiCommon.BAO;   namespace TaxiCommon.CompositeEvents { public class TaxiOnMoveEvent:CompositePresentationEvent<TaxiOnMove> { } }   TaxiOnMove.cs includes the properties which we want to exchange between the parties, FareView and TotalView. using System;   namespace TaxiCommon.BAO { public class TaxiOnMove { public TimeSpan MinutesAtTweleveMPH { get; set; } public double MilesAtSixMPH { get; set; } } }   Lets take a look into FareViewodel (Notifier) and how it raises the event.  Here we are raising the event by getting the event through GetEvent<..>() and publishing it with the payload private void OnAddMinutes(object obj) { TaxiOnMove payload = new TaxiOnMove(); if(MilesAtSixMPH != null) payload.MilesAtSixMPH = MilesAtSixMPH.Value; if(MinutesAtTweleveMPH != null) payload.MinutesAtTweleveMPH = new TimeSpan(0,0,MinutesAtTweleveMPH.Value,0);   _eventAggregator.GetEvent<TaxiOnMoveEvent>().Publish(payload); ResetMinutesAndMiles(); } And TotalViewModel(Observer) subscribes to notifications by getting the event through GetEvent<..>() namespace TaxiModules.ViewModels { public class TotalViewModel:ObservableBase { .... private IEventAggregator _eventAggregator;   public TotalViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; ... }   private void SubscribeToEvents() { _eventAggregator.GetEvent<TaxiStartedEvent>() .Subscribe(OnTaxiStarted, ThreadOption.UIThread,false,(filter) => true); _eventAggregator.GetEvent<TaxiOnMoveEvent>() .Subscribe(OnTaxiMove, ThreadOption.UIThread, false, (filter) => true); _eventAggregator.GetEvent<TaxiResetEvent>() .Subscribe(OnTaxiReset, ThreadOption.UIThread, false, (filter) => true); }   ... private void OnTaxiMove(TaxiOnMove taxiOnMove) { OnMoveFare fare = new OnMoveFare(taxiOnMove); Fares.Add(fare); SetTotalFare(new []{fare}); }   .... 7. MVVM through example In this section we are going to look into MVVM implementation through example.  I have all the modules declared in a single project, TaxiModules, again it is not necessary to have them into one project. Once the user logs into the application, will be greeted with the ‘Engage the Taxi’ screen which is made of two user controls, FareView.xaml and TotalView.Xaml. As you can see from the solution explorer, each of them have their own code behind files and  ViewModel classes, FareViewMode.cs, TotalViewModel.cs Lets take a look in to the FareView and how it interacts with FareViewModel using MVVM implementation. FareView.xaml acts as a view and FareViewMode.cs is it’s view model. The FareView code behind class   namespace TaxiModules.Views { /// <summary> /// Interaction logic for FareView.xaml /// </summary> public partial class FareView : UserControl { public FareView(FareViewModel viewModel) { InitializeComponent(); this.Loaded += (s, e) => { this.DataContext = viewModel; }; } } } The FareView is bound to FareViewModel through the data context  and you shall observe that DataContext is of type Object, i.e. the FareView doesn’t really know the type of ViewModel (FareViewModel). This helps separation of View and ViewModel as View and ViewModel are independent of each other, you can bind FareView to FareViewModel2 as well and the application compiles just fine. Lets take a look into FareView xaml file  <UserControl x:Class="TaxiModules.Views.FareView" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Toolkit="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit" xmlns:Commands="clr-namespace:Microsoft.Practices.Prism.Commands;assembly=Microsoft.Practices.Prism"> <Grid Margin="10" > ....   <Border Style="{DynamicResource innerBorder}" Grid.Row="0" Grid.Column="0" Grid.RowSpan="11" Grid.ColumnSpan="2" Panel.ZIndex="1"/>   <Label Grid.Row="0" Content="Engage the Taxi" Style="{DynamicResource innerHeader}"/> <Label Grid.Row="1" Content="Select the State"/> <ComboBox Grid.Row="1" Grid.Column="1" ItemsSource="{Binding States}" Height="auto"> <ComboBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding Name}"/> </DataTemplate> </ComboBox.ItemTemplate> <ComboBox.SelectedItem> <Binding Path="SelectedState" Mode="TwoWay"/> </ComboBox.SelectedItem> </ComboBox> <Label Grid.Row="2" Content="Select the Date of Entry"/> <Toolkit:DatePicker Grid.Row="2" Grid.Column="1" SelectedDate="{Binding DateOfEntry, ValidatesOnDataErrors=true}" /> <Label Grid.Row="3" Content="Enter time 24hr format"/> <TextBox Grid.Row="3" Grid.Column="1" Text="{Binding TimeOfEntry, TargetNullValue=''}"/> <Button Grid.Row="4" Grid.Column="1" Content="Start the Meter" Commands:Click.Command="{Binding StartMeterCommand}" />   <Label Grid.Row="5" Content="Run the Taxi" Style="{DynamicResource innerHeader}"/> <Label Grid.Row="6" Content="Number of Miles &lt;@6mph"/> <TextBox Grid.Row="6" Grid.Column="1" Text="{Binding MilesAtSixMPH, TargetNullValue='', ValidatesOnDataErrors=true}"/> <Label Grid.Row="7" Content="Number of Minutes @12mph"/> <TextBox Grid.Row="7" Grid.Column="1" Text="{Binding MinutesAtTweleveMPH, TargetNullValue=''}"/> <Button Grid.Row="8" Grid.Column="1" Content="Add Minutes and Miles " Commands:Click.Command="{Binding AddMinutesCommand}"/> <Label Grid.Row="9" Content="Other Operations" Style="{DynamicResource innerHeader}"/> <Button Grid.Row="10" Grid.Column="1" Content="Reset the Meter" Commands:Click.Command="{Binding ResetCommand}"/>   </Grid> </UserControl> The highlighted code from the above code shows data binding, for example ComboBox which displays list of states has it’s ItemsSource bound to States property, with DataTemplate bound to Name and SelectedItem  to SelectedState. You might be wondering what are all these properties and how it is able to bind to them.  The answer lies in data context, i.e., when you bound a control, WPF looks for data context on the root object (Grid in this case) and if it can’t find data context it will look into root’s root, i.e. FareView UserControl and it is bound to FareViewModel.  Each of those properties have be declared on the ViewModel for the View to bind correctly. To put simply, View is bound to ViewModel through data context of type object and every control that is bound on the View actually binds to the public property on the ViewModel. Lets look into the ViewModel code (the following code is not an exact copy of FareViewMode.cs, pasted relevant code for this section)   namespace TaxiModules.ViewModels { public class FareViewModel:ObservableBase, IDataErrorInfo { public List<USState> States { get { return USStates.StateList; } }   public USState SelectedState { get { return _selectedState; } set { _selectedState = value; RaisePropertyChanged(_selectedStatePropertyName); } }   public DateTime? DateOfEntry { get { return _dateOfEntry; } set { _dateOfEntry = value; RaisePropertyChanged(_dateOfEntryPropertyName); } }   public TimeSpan? TimeOfEntry { get { return _timeOfEntry; } set { _timeOfEntry = value; RaisePropertyChanged(_timeOfEntryPropertyName); } }   public double? MilesAtSixMPH { get { return _milesAtSixMPH; } set { _milesAtSixMPH = value; RaisePropertyChanged(_distanceAtSixMPHPropertyName); } }   public int? MinutesAtTweleveMPH { get { return _minutesAtTweleveMPH; } set { _minutesAtTweleveMPH = value; RaisePropertyChanged(_minutesAtTweleveMPHPropertyName); } }   public ICommand StartMeterCommand { get { if(_startMeterCommand == null) { _startMeterCommand = new DelegateCommand<object>(OnStartMeter, CanStartMeter); } return _startMeterCommand; } }   public ICommand AddMinutesCommand { get { if(_addMinutesCommand == null) { _addMinutesCommand = new DelegateCommand<object>(OnAddMinutes, CanAddMinutes); } return _addMinutesCommand; } }   public ICommand ResetCommand { get { if(_resetCommand == null) { _resetCommand = new DelegateCommand<object>(OnResetCommand); } return _resetCommand; } }   } private void OnStartMeter(object obj) { _eventAggregator.GetEvent<TaxiStartedEvent>().Publish( new TaxiStarted() { EngagedOn = DateOfEntry.Value.Date + TimeOfEntry.Value, EngagedState = SelectedState.Value });   _isMeterStarted = true; OnPropertyChanged(this,null); } And views communicate user actions like button clicks, tree view item selections, etc using commands. When user clicks on ‘Start the Meter’ button it invokes the method StartMeterCommand, which calls the method OnStartMeter which publishes the event to TotalViewModel using event aggregator  and TaxiStartedEvent. namespace TaxiModules.ViewModels { public class TotalViewModel:ObservableBase { ... private IEventAggregator _eventAggregator;   public TotalViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator;   InitializePropertyNames(); InitializeModel(); SubscribeToEvents(); }   public decimal? TotalFare { get { return _totalFare; } set { _totalFare = value; RaisePropertyChanged(_totalFarePropertyName); } } .... private void SubscribeToEvents() { _eventAggregator.GetEvent<TaxiStartedEvent>().Subscribe(OnTaxiStarted, ThreadOption.UIThread,false,(filter) => true); _eventAggregator.GetEvent<TaxiOnMoveEvent>().Subscribe(OnTaxiMove, ThreadOption.UIThread, false, (filter) => true); _eventAggregator.GetEvent<TaxiResetEvent>().Subscribe(OnTaxiReset, ThreadOption.UIThread, false, (filter) => true); }   private void OnTaxiStarted(TaxiStarted taxiStarted) { Fares.Add(new EntryFare()); Fares.Add(new StateTaxFare(taxiStarted)); Fares.Add(new NightSurchargeFare(taxiStarted)); Fares.Add(new PeakHourWeekdayFare(taxiStarted));   SetTotalFare(Fares); }   private void SetTotalFare(IEnumerable<IFare> fares) { TotalFare = (_totalFare ?? 0) + TaxiFareHelper.GetTotalFare(fares); } ....   } }   TotalViewModel subscribes to events, TaxiStartedEvent and rest. When TaxiStartedEvent gets invoked it calls the OnTaxiStarted method which sets the total fare which includes entry fee, state tax, nightly surcharge, peak hour weekday fare.   Note that TotalViewModel derives from ObservableBase which implements the method RaisePropertyChanged which we are invoking in Set of TotalFare property, i.e, once we update the TotalFare property it raises an the event that  allows the TotalFare text box to fetch the new value through the data context. ViewModel is communicating with View through data context and it has no knowledge about View, helping in loose coupling of ViewModel and View.   I have attached the source code (.Net 4.0, Prism 4.0, VS 2010) , download and play with it and don’t forget to leave your comments.  

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  • 26 Days: Countdown to Oracle OpenWorld 2012

    - by Michael Snow
    Welcome to our countdown to Oracle OpenWorld! Oracle OpenWorld 2012 is just around the corner. In less than 26 days, San Francisco will be invaded by an expected 50,000 people from all over the world. Here on the Oracle WebCenter team, we’ve all been working to help make the experience a great one for all our WebCenter customers. For a sneak peak  – we’ll be spending this week giving you a teaser of what to look forward to if you are joining us in San Francisco from September 30th through October 4th. We have Oracle WebCenter sessions covering all topics imaginable. Take a look and use the tools we provide to build out your schedule in advance and reserve your seats in your favorite sessions.  That gives you plenty of time to plan for your week with us in San Francisco. If unfortunately, your boss denied your request to attend - there are still some ways that you can join in the experience virtually On-Demand. This year - we are expanding even more up North of Market Street and will be taking over Union Square as well. Check out this map of San Francisco to get a sense of how much of a footprint Oracle OpenWorld has grown to this year. With so much to see and so many sessions to learn from - its no wonder that people get excited. Add to that a good mix of fun and all of the possible WebCenter sessions you could attend - you won't want to sleep at all to take full advantage of such an opportunity. We'll also have our annual WebCenter Customer Appreciation reception - stay tuned this week for some more info on registration to make sure you'll be able to join us. If you've been following the America's Cup at all and believe in EXTREME PERFORMANCE you'll definitely want to take a look at this video from last year's OpenWorld Keynote. 12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Important OpenWorld Links:  Attendee / Presenters Toolkit Oracle Schedule Builder WebCenter Sessions (listed in the catalog under Fusion Middleware as "Portals, Sites, Content, and Collaboration" ) Oracle Music Festival - AMAZING Line up!!  Oracle Customer Appreciation Night -LOOK HERE!! Oracle OpenWorld LIVE On-Demand Here are all the WebCenter sessions broken down by day for your viewing pleasure. Monday, October 1st CON8885 - Simplify CRM Engagement with Contextual Collaboration Are your sales teams disconnected and disengaged? Do you want a tool for easily connecting expertise across your organization and providing visibility into the complete sales process? Do you want a way to enhance and retain organization knowledge? Oracle Social Network is the answer. Attend this session to learn how to make CRM easy, effective, and efficient for use across virtual sales teams. Also learn how Oracle Social Network can drive sales force collaboration with natural conversations throughout the sales cycle, promote sales team productivity through purposeful social networking without the noise, and build cross-team knowledge by integrating conversations with CRM and other business applications. CON8268 - Oracle WebCenter Strategy: Engaging Your Customers. Empowering Your Business Oracle WebCenter is a user engagement platform for social business, connecting people and information. Attend this session to learn about the Oracle WebCenter strategy, and understand where Oracle is taking the platform to help companies engage customers, empower employees, and enable partners. Business success starts with ensuring that everyone is engaged with the right people and the right information and can access what they need through the channel of their choice—Web, mobile, or social. Are you giving customers, employees, and partners the best-possible experience? Come learn how you can! ¶ HOL10208 - Add Social Capabilities to Your Enterprise Applications Oracle Social Network enables you to add real-time collaboration capabilities into your enterprise applications, so that conversations can happen directly within your business systems. In this hands-on lab, you will try out the Oracle Social Network product to collaborate with other attendees, using real-time conversations with document sharing capabilities. Next you will embed social capabilities into a sample Web-based enterprise application, using embedded UI components. Experts will also write simple REST-based integrations, using the Oracle Social Network API to programmatically create social interactions. ¶ CON8893 - Improve Employee Productivity with Intuitive and Social Work Environments Social technologies have already transformed the ways customers, employees, partners, and suppliers communicate and stay informed. Forward-thinking organizations today need technologies and infrastructures to help them advance to the next level and integrate social activities with business applications to deliver a user experience that simplifies business processes and enterprise application engagement. Attend this session to hear from an innovative Oracle Social Network customer and learn how you can improve productivity with intuitive and social work environments and empower your employees with innovative social tools to enable contextual access to content and dynamic personalization of solutions. ¶ CON8270 - Oracle WebCenter Content Strategy and Vision Oracle WebCenter provides a strategic content infrastructure for managing documents, images, e-mails, and rich media files. With a single repository, organizations can address any content use case, such as accounts payable, HR onboarding, document management, compliance, records management, digital asset management, or Website management. In this session, learn about future plans for how Oracle WebCenter will address new use cases as well as new integrations with Oracle Fusion Middleware and Oracle Applications, leveraging your investments by making your users more productive and error-free. ¶ CON8269 - Oracle WebCenter Sites Strategy and Vision Oracle’s Web experience management solution, Oracle WebCenter Sites, enables organizations to use the online channel to drive customer acquisition and brand loyalty. It helps marketers and business users easily create and manage contextually relevant, social, interactive online experiences across multiple channels on a global scale. In this session, learn about future plans for how Oracle WebCenter Sites will provide you with the tools, capabilities, and integrations you need in order to continue to address your customers’ evolving requirements for engaging online experiences and keep moving your business forward. ¶ CON8896 - Living with SharePoint SharePoint is a popular platform, but it’s not always the best fit for Oracle customers. In this session, you’ll discover the technical and nontechnical limitations and pitfalls of SharePoint and learn about Oracle alternatives for collaboration, portals, enterprise and Web content management, social computing, and application integration. The presentation shows you how to integrate with SharePoint when business or IT requirements dictate and covers cloud-based (Office 365) and on-premises versions of SharePoint. Presented by a former Microsoft director of SharePoint product management and backed by independent customer research, this session will prepare you to answer the question “Why don’t we just use SharePoint for that?’ the next time it comes up in your organization. ¶ CON7843 - Content-Enabling Enterprise Processes with Oracle WebCenter Organizations today continually strive to automate business processes, reduce costs, and improve efficiency. Many business processes are content-intensive and unstructured, requiring ad hoc collaboration, and distributed in nature, requiring many approvals and generating huge volumes of paper. In this session, learn how Oracle and SYSTIME have partnered to help a customer content-enable its enterprise with Oracle WebCenter Content and Oracle WebCenter Imaging 11g and integrate them with Oracle Applications. ¶ CON6114 - Tape Robotics’ Newest Superhero: Now Fueled by Oracle Software For small, midsize, and rapidly growing businesses that want the most energy-efficient, scalable storage infrastructure to meet their rapidly growing data demands, Oracle’s most recent addition to its award-winning tape portfolio leverages several pieces of Oracle software. With Oracle Linux, Oracle WebLogic, and Oracle Fusion Middleware tools, the library achieves a higher level of usability than previous products while offering customers a familiar interface for management, plus ease of use. This session examines the competitive advantages of the tape library and how Oracle software raises customer satisfaction. Learn how the combination of Oracle engineered systems, Oracle Secure Backup, and Oracle’s StorageTek tape libraries provide end-to-end coverage of your data. ¶ CON9437 - Mobile Access Management With more than five billion mobile devices on the planet and an increasing number of users using their own devices to access corporate data and applications, securely extending identity management to mobile devices has become a hot topic. This session focuses on how to extend your existing identity management infrastructure and policies to securely and seamlessly enable mobile user access. CON7815 - Customer Experience Online in Cloud: Oracle WebCenter Sites, Oracle ATG Apps, Oracle Exalogic Oracle WebCenter Sites and Oracle’s ATG product line together can provide a compelling marketing and e-commerce experience. When you couple them with the extreme performance of Oracle Exalogic, you’ll see unmatched scalability that provides you with a true cloud-based solution. In this session, you’ll learn how running Oracle WebCenter Sites and ATG applications on Oracle Exalogic delivers both a private and a public cloud experience. Find out what it takes to get these systems working together and delivering engaging Web experiences. Even if you aren’t considering Oracle Exalogic today, the rich Web experience of Oracle WebCenter, paired with the depth of the ATG product line, can provide your business full support, from merchandising through sale completion. ¶ CON8271 - Oracle WebCenter Portal Strategy and Vision To innovate and keep a competitive edge, organizations need to leverage the power of agile and responsive Web applications. Oracle WebCenter Portal enables you to do just that, by delivering intuitive user experiences for enterprise applications to drive innovation with composite applications and mashups. Attend this session to learn firsthand from customers how Oracle WebCenter Portal extends the value of existing enterprise applications, business processes, and content; delivers a superior business user experience; and maximizes limited IT resources. ¶ CON8880 - The Connected Customer Experience Begins with the Online Channel There’s a lot of talk these days about how to connect the customer journey across various touchpoints—from Websites and e-commerce to call centers and in-store—to provide experiences that are more relevant and engaging and ultimately gain competitive edge. Doing it all at once isn’t a realistic objective, so where do you start? Come to this session, and hear about three steps you can take that can help you begin your journey toward delivering the connected customer experience. You’ll hear how Oracle now has an integrated digital marketing platform for your corporate Website, your e-commerce site, your self-service portal, and your marketing and loyalty campaigns, and you’ll learn what you can do today to begin executing on your customer experience initiatives. ¶ GEN11451 - General Session: Building Mobile Applications with Oracle Cloud With the prevalence of smart mobile devices, companies are facing an increased demand to provide access to data and applications from new channels. However, developing applications for mobile devices poses some unique challenges. Come to this session to learn how Oracle addresses these challenges, offering a simpler way to develop and deploy cross-device mobile applications. See how Oracle Cloud enables you to access applications, data, and services from mobile channels in an easier way.  CON8272 - Oracle Social Network Strategy and Vision One key way of increasing employee productivity is by bringing people, processes, and information together—providing new social capabilities to enable business users to quickly correspond and collaborate on business activities. Oracle WebCenter provides a user engagement platform with social and collaborative technologies to empower business users to focus on their key business processes, applications, and content in the context of their role and process. Attend this session to hear how the latest social capabilities in Oracle Social Network are enabling organizations to transform themselves into social businesses.  --- Tuesday, October 2nd HOL10194 - Enterprise Content Management Simplified: Oracle WebCenter Content’s Next-Generation UI Regardless of the nature of your business, unstructured content underpins many of its daily functions. Whether you are working with traditional presentations, spreadsheets, or text documents—or even with digital assets such as images and multimedia files—your content needs to be accessible and manageable in convenient and intuitive ways to make working with the content easier. Additionally, you need the ability to easily share documents with coworkers to facilitate a collaborative working environment. Come to this session to see how Oracle WebCenter Content’s next-generation user interface helps modern knowledge workers easily manage personal and enterprise documents in a collaborative environment.¶ CON8877 - Develop a Mobile Strategy with Oracle WebCenter: Engage Customers, Employees, and Partners Mobile technology has gone from nice-to-have to a cornerstone of user engagement. Mobile access enables users to have information available at their fingertips, enabling them to take action the moment they make a decision, interact in the moment of convenience, and take advantage of new service offerings in their preferred channels. All your employees have your mobile applications in their pocket; now what are you going to do? It is a critical step for companies to think through what their employees, customers, and partners really need on their devices. Attend this session to see how Oracle WebCenter enables you to better engage your customers, employees, and partners by providing a unified experience across multiple channels. ¶ CON9447 - Enabling Access for Hundreds of Millions of Users How do you grow your business by identifying, authenticating, authorizing, and federating users on the Web, leveraging social identity and the open source OAuth protocol? How do you scale your access management solution to support hundreds of millions of users? With social identity support out of the box, Oracle’s access management solution is also benchmarked for 250-million-user deployment according to real-world customer scenarios. In this session, you will learn about the social identity capability and the 250-million-user benchmark testing of Oracle Access Manager and Oracle Adaptive Access Manager running on Oracle Exalogic and Oracle Exadata. ¶ HOL10207 - Build an Intranet Portal with Oracle WebCenter In this hands-on lab, you’ll work with Oracle WebCenter Portal and Oracle WebCenter Content to build out an enterprise portal that maximizes the productivity of teams and individual contributors. Using browser-based tools, you’ll manage site resources such as page styles, templates, and navigation. You’ll edit content stored in Oracle WebCenter Content directly from your portal. You’ll also experience the latest features that promote collaboration, social networking, and personal productivity. ¶ CON2906 - Get Proactive: Best Practices for Maintaining Oracle Fusion Middleware You chose Oracle Fusion Middleware products to help your organization deliver superior business results. Now learn how to take full advantage of your software with all the great tools, resources, and product updates you’re entitled to through Oracle Support. In this session, Oracle product experts provide proven best practices to help you work more efficiently, plan and prepare for upgrades and patching more effectively, and manage risk. Topics include configuration management tools, remote diagnostics, My Oracle Support Community, and My Oracle Support Lifecycle Advisors. New users and Oracle Fusion Middleware experts alike are guaranteed to leave with fresh ideas and practical, easy-to-implement next steps. ¶ CON8878 - Oracle WebCenter’s Cloud Strategy: From Social and Platform Services to Mashups Cloud computing represents a paradigm shift in how we build applications, automate processes, collaborate, and share and in how we secure our enterprise. Additionally, as you adopt cloud-based services in your organization, it’s likely that you will still have many critical on-premises applications running. With these mixed environments, multiple user interfaces, different security, and multiple datasources and content sources, how do you start evolving your strategy to account for these challenges? Oracle WebCenter offers a complete array of technologies enabling you to solve these challenges and prepare you for the cloud. Attend this session to learn how you can use Oracle WebCenter in the cloud as well as create on-premises and cloud application mash-ups. ¶ CON8901 - Optimize Enterprise Business Processes with Oracle WebCenter and Oracle BPM Do you have business processes that span multiple applications? Are you grappling with how to have visibility across these business processes; how to manage content that is associated with these processes; and, most importantly, how to model and optimize these business processes? Attend this session to hear how Oracle WebCenter and Oracle Business Process Management provide a unique set of integrated solutions to provide a composite application dashboard across these business processes and offer a solution for content-centric business processes. ¶ CON8883 - Deliver Engaging Interfaces to Oracle Applications with Oracle WebCenter Critical business processes live within enterprise applications, and application users need to manage and execute these processes as effectively as possible. Oracle provides a comprehensive user engagement platform to increase user productivity and optimize overall processes within Oracle Applications—Oracle E-Business Suite and Oracle’s Siebel, PeopleSoft, and JD Edwards product families—and third-party applications. Attend this session to learn how you can integrate these applications with Oracle WebCenter to deliver composite application dashboards to your end users—whether they are your customers, partners, or employees—for enhanced usability and Web 2.0–enabled enterprise portals.¶ Wednesday, October 3rd CON8895 - Future-Ready Intranets: How Aramark Re-engineered the Application Landscape There are essential techniques and technologies you can use to deliver employee portals that garner higher productivity, improve business efficiency, and increase user engagement. Attend this session to learn how you can leverage Oracle WebCenter Portal as a user engagement platform for bringing together business process management, enterprise content management, and business intelligence into a highly relevant and integrated experience. Hear how Aramark has leveraged Oracle WebCenter Portal and Oracle WebCenter Content to deliver a unified workspace providing simpler navigation and processing, consolidation of tools, easy access to information, integrated search, and single sign-on. ¶ CON8886 - Content Consolidation: Save Money, Increase Efficiency, and Eliminate Silos Organizations are looking for ways to save money and be more efficient. With content in many different places, it’s difficult to know where to look for a document and whether the document is the most current version. With Oracle WebCenter, content can be consolidated into one best-of-breed repository that is secure, scalable, and integrated with your business processes and applications. Users can find the content they need, where they need it, and ensure that it is the right content. This session covers content challenges that affect your business; content consolidation that can lead to savings in storage and administration costs and can lower risks; and how companies are realizing savings. ¶ CON8911 - Improve Online Experiences for Customers and Partners with Self-Service Portals Are you able to provide your customers and partners an easy-to-use online self-service experience? Are you processing high-volume transactions and struggling with call center bottlenecks or back-end systems that won’t integrate, causing order delays and customer frustration? Are you looking to target content such as product and service offerings to your end users? This session shares approaches to providing targeted delivery as well as strategies and best practices for transforming your business by providing an intuitive user experience for your customers and partners. ¶ CON6156 - Top 10 Ways to Integrate Oracle WebCenter Content This session covers 10 common ways to integrate Oracle WebCenter Content with other enterprise applications and middleware. It discusses out-of-the-box modules that provide expanded features in Oracle WebCenter Content—such as enterprise search, SOA, and BPEL—as well as developer tools you can use to create custom integrations. The presentation also gives guidance on which integration option may work best in your environment. ¶ HOL10207 - Build an Intranet Portal with Oracle WebCenter In this hands-on lab, you’ll work with Oracle WebCenter Portal and Oracle WebCenter Content to build out an enterprise portal that maximizes the productivity of teams and individual contributors. Using browser-based tools, you’ll manage site resources such as page styles, templates, and navigation. You’ll edit content stored in Oracle WebCenter Content directly from your portal. You’ll also experience the latest features that promote collaboration, social networking, and personal productivity. ¶ CON7817 - Migration to Oracle WebCenter Imaging 11g Customers today continually strive to automate business processes, reduce costs, and improve efficiency. The accounts payable process—which is often distributed in nature, requires many approvals, and generates huge volumes of paper invoices—is automated by many customers. In this session, learn how Oracle and SYSTIME have partnered to help a customer migrate its existing Oracle Imaging and Process Management Release 7.6 to the latest Oracle WebCenter Imaging 11g and integrate it with Oracle’s JD Edwards family of products. ¶ CON8910 - How to Engage Customers Across Web, Mobile, and Social Channels Whether on desktops at the office, on tablets at home, or on mobile phones when on the go, today’s customers are always connected. To engage today’s customers, you need to make the online customer experience connected and consistent across a host of devices and multiple channels, including Web, mobile, and social networks. Managing this multichannel environment can result in lots of headaches without the right tools. Attend this session to learn how Oracle WebCenter Sites solves the challenge of multichannel customer engagement. ¶ HOL10206 - Oracle WebCenter Sites 11g: Transforming the Content Contributor Experience Oracle WebCenter Sites 11g makes it easy for marketers and business users to contribute to and manage Websites with the new visual, contextual, and intuitive Web authoring interface. In this hands-on lab, you will create and manage content for a sports-themed Website, using many of the new and enhanced features of the 11g release. ¶ CON8900 - Building Next-Generation Portals: An Interactive Customer Panel Discussion Social and collaborative technologies have changed how people interact, learn, and collaborate, and providing a modern, social Web presence is imperative to remain competitive in today’s market. Can your business benefit from a more collaborative and interactive portal environment for employees, customers, and partners? Attend this session to hear from Oracle WebCenter Portal customers as they share their strategies and best practices for providing users with a modern experience that adapts to their needs and includes personalized access to content in context. The panel also addresses how customers have benefited from creating next-generation portals by migrating from older portal technologies to Oracle WebCenter Portal. ¶ CON9625 - Taking Control of Oracle WebCenter Security Organizations are increasingly looking to extend their Oracle WebCenter portal for social business, to serve external users and provide seamless access to the right information. In particular, many organizations are extending Oracle WebCenter in a business-to-business scenario requiring secure identification and authorization of business partners and their users. This session focuses on how customers are leveraging, securing, and providing access control to Oracle WebCenter portal and mobile solutions. You will learn best practices and hear real-world examples of how to provide flexible and granular access control for Oracle WebCenter deployments, using Oracle Platform Security Services and Oracle Access Management Suite product offerings. ¶ CON8891 - Extending Social into Enterprise Applications and Business Processes Oracle Social Network is an extensible social platform that enables contextual collaboration within enterprise applications and business processes, providing relevant data from across various enterprise systems in one place. Attend this session to see how an Oracle Social Network customer is integrating multiple applications—such as CRM, HCM, and business processes—into Oracle Social Network and Oracle WebCenter to enable individuals and teams to solve complex cross-organizational business problems more effectively by utilizing the social enterprise. ¶ Thursday, October 4th CON8899 - Becoming a Social Business: Stories from the Front Lines of Change What does it really mean to be a social business? How can you change our organization to embrace social approaches? What pitfalls do you need to avoid? In this lively panel discussion, customer and industry thought leaders in social business explore these topics and more as they share their stories of the good, the bad, and the ugly that can happen when embracing social methods and technologies to improve business success. Using moderated questions and open Q&A from the audience, the panel discusses vital topics such as the critical factors for success, the major issues to avoid, how to gain senior executive support for social efforts, how to handle undesired behavior, and how to measure business impact. It takes a thought-provoking look at becoming a social business from the inside. ¶ CON6851 - Oracle WebCenter and Oracle Business Intelligence Enterprise Edition to Create Vendor Portals Large manufacturers of grocery items routinely find themselves depending on the inventory management expertise of their wholesalers and distributors. Inventory costs can be managed more efficiently by the manufacturers if they have better insight into the inventory levels of items carried by their distributors. This creates a unique opportunity for distributors and wholesalers to leverage this knowledge into a revenue-generating subscription service. Oracle Business Intelligence Enterprise Edition and Oracle WebCenter Portal play a key part in enabling creation of business-managed business intelligence portals for vendors. This session discusses one customer that implemented this by leveraging Oracle WebCenter and Oracle Business Intelligence Enterprise Edition. ¶ CON8879 - Provide a Personalized and Consistent Customer Experience in Your Websites and Portals Your customers engage with your company online in different ways throughout their journey—from prospecting by acquiring information on your corporate Website to transacting through self-service applications on your customer portal—and then the cycle begins again when they look for new products and services. Ensuring that the customer experience is consistent and personalized across online properties—from branding and content to interactions and transactions—can be a daunting task. Oracle WebCenter enables you to speak and interact with your customers with one voice across your Websites and portals by providing an integrated platform for delivery of self-service and engagement that unifies and personalizes the online experience. Learn more in this session. ¶ CON8898 - Land Mines, Potholes, and Dirt Roads: Navigating the Way to ECM Nirvana Ten years ago, people were predicting that by this time in history, we’d be some kind of utopian paperless society. As we all know, we’re not there yet, but are we getting closer? What is keeping companies from driving down the road to enterprise content management bliss? Most people understand that using ECM as a central platform enables organizations to expedite document-centric processes, but most business processes in organizations are still heavily paper-based. Many of these processes could be automated and improved with an ECM platform infrastructure. In this panel discussion, you’ll hear from Oracle WebCenter customers that have already solved some of these challenges as they share their strategies for success and roads to avoid along your journey. ¶ CON8908 - Oracle WebCenter Portal: Creating and Using Content Presenter Templates Oracle WebCenter Portal applications use task flows to display and integrate content stored in the Oracle WebCenter Content server. Among the most flexible task flows is Content Presenter, which renders various types of content on an Oracle WebCenter Portal page. Although Oracle WebCenter Portal comes with a set of predefined Content Presenter templates, developers can create their own templates for specific rendering needs. This session shows the lifecycle of developing Content Presenter task flows, including how to create, package, import, modify at runtime, and use such templates. In addition to simple examples with Oracle Application Development Framework (Oracle ADF) UI elements to render the content, it shows how to use other UI technologies, CSS files, and JavaScript libraries. ¶ CON8897 - Using Web Experience Management to Drive Online Marketing Success Every year, the online channel becomes more imperative for driving organizational top-line revenue, but for many companies, mastering how to best market their products and services in a fast-evolving online world with high customer expectations for personalized experiences can be a complex proposition. Come to this panel discussion, and hear directly from online marketers how they are succeeding today by using Web experience management to drive marketing success, using capabilities such as targeting and optimization, user-generated content, mobile site publishing, and site visitor personalization to deliver engaging online experiences. ¶ CON8892 - Oracle’s Journey to Social Business Social business is a revolution, one that is causing rapidly accelerating change in how companies and customers engage with one another and how employees work together. Oracle’s goal in becoming a social business is to create a socially connected organization in which working collaboratively across geographical locations, lines of business, and management chains is second nature, enabling innovative solutions to business challenges. We can achieve this by connecting the right people, finding the right content, communicating with the right people, collaborating at the right time, and building the right communities in the right context—all ready in the CLOUD. Attend this session to see how Oracle is transforming itself into a social business. ¶  ------------ If you've read all the way to the end here - we are REALLY looking forward to seeing you in San Francisco.

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  • Capturing and Transforming ASP.NET Output with Response.Filter

    - by Rick Strahl
    During one of my Handlers and Modules session at DevConnections this week one of the attendees asked a question that I didn’t have an immediate answer for. Basically he wanted to capture response output completely and then apply some filtering to the output – effectively injecting some additional content into the page AFTER the page had completely rendered. Specifically the output should be captured from anywhere – not just a page and have this code injected into the page. Some time ago I posted some code that allows you to capture ASP.NET Page output by overriding the Render() method, capturing the HtmlTextWriter() and reading its content, modifying the rendered data as text then writing it back out. I’ve actually used this approach on a few occasions and it works fine for ASP.NET pages. But this obviously won’t work outside of the Page class environment and it’s not really generic – you have to create a custom page class in order to handle the output capture. [updated 11/16/2009 – updated ResponseFilterStream implementation and a few additional notes based on comments] Enter Response.Filter However, ASP.NET includes a Response.Filter which can be used – well to filter output. Basically Response.Filter is a stream through which the OutputStream is piped back to the Web Server (indirectly). As content is written into the Response object, the filter stream receives the appropriate Stream commands like Write, Flush and Close as well as read operations although for a Response.Filter that’s uncommon to be hit. The Response.Filter can be programmatically replaced at runtime which allows you to effectively intercept all output generation that runs through ASP.NET. A common Example: Dynamic GZip Encoding A rather common use of Response.Filter hooking up code based, dynamic  GZip compression for requests which is dead simple by applying a GZipStream (or DeflateStream) to Response.Filter. The following generic routines can be used very easily to detect GZip capability of the client and compress response output with a single line of code and a couple of library helper routines: WebUtils.GZipEncodePage(); which is handled with a few lines of reusable code and a couple of static helper methods: /// <summary> ///Sets up the current page or handler to use GZip through a Response.Filter ///IMPORTANT:  ///You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() {     HttpResponse Response = HttpContext.Current.Response;     if(IsGZipSupported())     {         stringAcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"];         if(AcceptEncoding.Contains("deflate"))         {             Response.Filter = newSystem.IO.Compression.DeflateStream(Response.Filter,                                        System.IO.Compression.CompressionMode.Compress);             Response.AppendHeader("Content-Encoding", "deflate");         }         else        {             Response.Filter = newSystem.IO.Compression.GZipStream(Response.Filter,                                       System.IO.Compression.CompressionMode.Compress);             Response.AppendHeader("Content-Encoding", "gzip");                            }     }     // Allow proxy servers to cache encoded and unencoded versions separately    Response.AppendHeader("Vary", "Content-Encoding"); } /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } GZipStream and DeflateStream are streams that are assigned to Response.Filter and by doing so apply the appropriate compression on the active Response. Response.Filter content is chunked So to implement a Response.Filter effectively requires only that you implement a custom stream and handle the Write() method to capture Response output as it’s written. At first blush this seems very simple – you capture the output in Write, transform it and write out the transformed content in one pass. And that indeed works for small amounts of content. But you see, the problem is that output is written in small buffer chunks (a little less than 16k it appears) rather than just a single Write() statement into the stream, which makes perfect sense for ASP.NET to stream data back to IIS in smaller chunks to minimize memory usage en route. Unfortunately this also makes it a more difficult to implement any filtering routines since you don’t directly get access to all of the response content which is problematic especially if those filtering routines require you to look at the ENTIRE response in order to transform or capture the output as is needed for the solution the gentleman in my session asked for. So in order to address this a slightly different approach is required that basically captures all the Write() buffers passed into a cached stream and then making the stream available only when it’s complete and ready to be flushed. As I was thinking about the implementation I also started thinking about the few instances when I’ve used Response.Filter implementations. Each time I had to create a new Stream subclass and create my custom functionality but in the end each implementation did the same thing – capturing output and transforming it. I thought there should be an easier way to do this by creating a re-usable Stream class that can handle stream transformations that are common to Response.Filter implementations. Creating a semi-generic Response Filter Stream Class What I ended up with is a ResponseFilterStream class that provides a handful of Events that allow you to capture and/or transform Response content. The class implements a subclass of Stream and then overrides Write() and Flush() to handle capturing and transformation operations. By exposing events it’s easy to hook up capture or transformation operations via single focused methods. ResponseFilterStream exposes the following events: CaptureStream, CaptureString Captures the output only and provides either a MemoryStream or String with the final page output. Capture is hooked to the Flush() operation of the stream. TransformStream, TransformString Allows you to transform the complete response output with events that receive a MemoryStream or String respectively and can you modify the output then return it back as a return value. The transformed output is then written back out in a single chunk to the response output stream. These events capture all output internally first then write the entire buffer into the response. TransformWrite, TransformWriteString Allows you to transform the Response data as it is written in its original chunk size in the Stream’s Write() method. Unlike TransformStream/TransformString which operate on the complete output, these events only see the current chunk of data written. This is more efficient as there’s no caching involved, but can cause problems due to searched content splitting over multiple chunks. Using this implementation, creating a custom Response.Filter transformation becomes as simple as the following code. To hook up the Response.Filter using the MemoryStream version event: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformStream += filter_TransformStream; Response.Filter = filter; and the event handler to do the transformation: MemoryStream filter_TransformStream(MemoryStream ms) { Encoding encoding = HttpContext.Current.Response.ContentEncoding; string output = encoding.GetString(ms.ToArray()); output = FixPaths(output); ms = new MemoryStream(output.Length); byte[] buffer = encoding.GetBytes(output); ms.Write(buffer,0,buffer.Length); return ms; } private string FixPaths(string output) { string path = HttpContext.Current.Request.ApplicationPath; // override root path wonkiness if (path == "/") path = ""; output = output.Replace("\"~/", "\"" + path + "/").Replace("'~/", "'" + path + "/"); return output; } The idea of the event handler is that you can do whatever you want to the stream and return back a stream – either the same one that’s been modified or a brand new one – which is then sent back to as the final response. The above code can be simplified even more by using the string version events which handle the stream to string conversions for you: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; and the event handler to do the transformation calling the same FixPaths method shown above: string filter_TransformString(string output) { return FixPaths(output); } The events for capturing output and capturing and transforming chunks work in a very similar way. By using events to handle the transformations ResponseFilterStream becomes a reusable component and we don’t have to create a new stream class or subclass an existing Stream based classed. By the way, the example used here is kind of a cool trick which transforms “~/” expressions inside of the final generated HTML output – even in plain HTML controls not HTML controls – and transforms them into the appropriate application relative path in the same way that ResolveUrl would do. So you can write plain old HTML like this: <a href=”~/default.aspx”>Home</a>  and have it turned into: <a href=”/myVirtual/default.aspx”>Home</a>  without having to use an ASP.NET control like Hyperlink or Image or having to constantly use: <img src=”<%= ResolveUrl(“~/images/home.gif”) %>” /> in MVC applications (which frankly is one of the most annoying things about MVC especially given the path hell that extension-less and endpoint-less URLs impose). I can’t take credit for this idea. While discussing the Response.Filter issues on Twitter a hint from Dylan Beattie who pointed me at one of his examples which does something similar. I thought the idea was cool enough to use an example for future demos of Response.Filter functionality in ASP.NET next I time I do the Modules and Handlers talk (which was great fun BTW). How practical this is is debatable however since there’s definitely some overhead to using a Response.Filter in general and especially on one that caches the output and the re-writes it later. Make sure to test for performance anytime you use Response.Filter hookup and make sure it' doesn’t end up killing perf on you. You’ve been warned :-}. How does ResponseFilterStream work? The big win of this implementation IMHO is that it’s a reusable  component – so for implementation there’s no new class, no subclassing – you simply attach to an event to implement an event handler method with a straight forward signature to retrieve the stream or string you’re interested in. The implementation is based on a subclass of Stream as is required in order to handle the Response.Filter requirements. What’s different than other implementations I’ve seen in various places is that it supports capturing output as a whole to allow retrieving the full response output for capture or modification. The exception are the TransformWrite and TransformWrite events which operate only active chunk of data written by the Response. For captured output, the Write() method captures output into an internal MemoryStream that is cached until writing is complete. So Write() is called when ASP.NET writes to the Response stream, but the filter doesn’t pass on the Write immediately to the filter’s internal stream. The data is cached and only when the Flush() method is called to finalize the Stream’s output do we actually send the cached stream off for transformation (if the events are hooked up) and THEN finally write out the returned content in one big chunk. Here’s the implementation of ResponseFilterStream: /// <summary> /// A semi-generic Stream implementation for Response.Filter with /// an event interface for handling Content transformations via /// Stream or String. /// <remarks> /// Use with care for large output as this implementation copies /// the output into a memory stream and so increases memory usage. /// </remarks> /// </summary> public class ResponseFilterStream : Stream { /// <summary> /// The original stream /// </summary> Stream _stream; /// <summary> /// Current position in the original stream /// </summary> long _position; /// <summary> /// Stream that original content is read into /// and then passed to TransformStream function /// </summary> MemoryStream _cacheStream = new MemoryStream(5000); /// <summary> /// Internal pointer that that keeps track of the size /// of the cacheStream /// </summary> int _cachePointer = 0; /// <summary> /// /// </summary> /// <param name="responseStream"></param> public ResponseFilterStream(Stream responseStream) { _stream = responseStream; } /// <summary> /// Determines whether the stream is captured /// </summary> private bool IsCaptured { get { if (CaptureStream != null || CaptureString != null || TransformStream != null || TransformString != null) return true; return false; } } /// <summary> /// Determines whether the Write method is outputting data immediately /// or delaying output until Flush() is fired. /// </summary> private bool IsOutputDelayed { get { if (TransformStream != null || TransformString != null) return true; return false; } } /// <summary> /// Event that captures Response output and makes it available /// as a MemoryStream instance. Output is captured but won't /// affect Response output. /// </summary> public event Action<MemoryStream> CaptureStream; /// <summary> /// Event that captures Response output and makes it available /// as a string. Output is captured but won't affect Response output. /// </summary> public event Action<string> CaptureString; /// <summary> /// Event that allows you transform the stream as each chunk of /// the output is written in the Write() operation of the stream. /// This means that that it's possible/likely that the input /// buffer will not contain the full response output but only /// one of potentially many chunks. /// /// This event is called as part of the filter stream's Write() /// operation. /// </summary> public event Func<byte[], byte[]> TransformWrite; /// <summary> /// Event that allows you to transform the response stream as /// each chunk of bytep[] output is written during the stream's write /// operation. This means it's possibly/likely that the string /// passed to the handler only contains a portion of the full /// output. Typical buffer chunks are around 16k a piece. /// /// This event is called as part of the stream's Write operation. /// </summary> public event Func<string, string> TransformWriteString; /// <summary> /// This event allows capturing and transformation of the entire /// output stream by caching all write operations and delaying final /// response output until Flush() is called on the stream. /// </summary> public event Func<MemoryStream, MemoryStream> TransformStream; /// <summary> /// Event that can be hooked up to handle Response.Filter /// Transformation. Passed a string that you can modify and /// return back as a return value. The modified content /// will become the final output. /// </summary> public event Func<string, string> TransformString; protected virtual void OnCaptureStream(MemoryStream ms) { if (CaptureStream != null) CaptureStream(ms); } private void OnCaptureStringInternal(MemoryStream ms) { if (CaptureString != null) { string content = HttpContext.Current.Response.ContentEncoding.GetString(ms.ToArray()); OnCaptureString(content); } } protected virtual void OnCaptureString(string output) { if (CaptureString != null) CaptureString(output); } protected virtual byte[] OnTransformWrite(byte[] buffer) { if (TransformWrite != null) return TransformWrite(buffer); return buffer; } private byte[] OnTransformWriteStringInternal(byte[] buffer) { Encoding encoding = HttpContext.Current.Response.ContentEncoding; string output = OnTransformWriteString(encoding.GetString(buffer)); return encoding.GetBytes(output); } private string OnTransformWriteString(string value) { if (TransformWriteString != null) return TransformWriteString(value); return value; } protected virtual MemoryStream OnTransformCompleteStream(MemoryStream ms) { if (TransformStream != null) return TransformStream(ms); return ms; } /// <summary> /// Allows transforming of strings /// /// Note this handler is internal and not meant to be overridden /// as the TransformString Event has to be hooked up in order /// for this handler to even fire to avoid the overhead of string /// conversion on every pass through. /// </summary> /// <param name="responseText"></param> /// <returns></returns> private string OnTransformCompleteString(string responseText) { if (TransformString != null) TransformString(responseText); return responseText; } /// <summary> /// Wrapper method form OnTransformString that handles /// stream to string and vice versa conversions /// </summary> /// <param name="ms"></param> /// <returns></returns> internal MemoryStream OnTransformCompleteStringInternal(MemoryStream ms) { if (TransformString == null) return ms; //string content = ms.GetAsString(); string content = HttpContext.Current.Response.ContentEncoding.GetString(ms.ToArray()); content = TransformString(content); byte[] buffer = HttpContext.Current.Response.ContentEncoding.GetBytes(content); ms = new MemoryStream(); ms.Write(buffer, 0, buffer.Length); //ms.WriteString(content); return ms; } /// <summary> /// /// </summary> public override bool CanRead { get { return true; } } public override bool CanSeek { get { return true; } } /// <summary> /// /// </summary> public override bool CanWrite { get { return true; } } /// <summary> /// /// </summary> public override long Length { get { return 0; } } /// <summary> /// /// </summary> public override long Position { get { return _position; } set { _position = value; } } /// <summary> /// /// </summary> /// <param name="offset"></param> /// <param name="direction"></param> /// <returns></returns> public override long Seek(long offset, System.IO.SeekOrigin direction) { return _stream.Seek(offset, direction); } /// <summary> /// /// </summary> /// <param name="length"></param> public override void SetLength(long length) { _stream.SetLength(length); } /// <summary> /// /// </summary> public override void Close() { _stream.Close(); } /// <summary> /// Override flush by writing out the cached stream data /// </summary> public override void Flush() { if (IsCaptured && _cacheStream.Length > 0) { // Check for transform implementations _cacheStream = OnTransformCompleteStream(_cacheStream); _cacheStream = OnTransformCompleteStringInternal(_cacheStream); OnCaptureStream(_cacheStream); OnCaptureStringInternal(_cacheStream); // write the stream back out if output was delayed if (IsOutputDelayed) _stream.Write(_cacheStream.ToArray(), 0, (int)_cacheStream.Length); // Clear the cache once we've written it out _cacheStream.SetLength(0); } // default flush behavior _stream.Flush(); } /// <summary> /// /// </summary> /// <param name="buffer"></param> /// <param name="offset"></param> /// <param name="count"></param> /// <returns></returns> public override int Read(byte[] buffer, int offset, int count) { return _stream.Read(buffer, offset, count); } /// <summary> /// Overriden to capture output written by ASP.NET and captured /// into a cached stream that is written out later when Flush() /// is called. /// </summary> /// <param name="buffer"></param> /// <param name="offset"></param> /// <param name="count"></param> public override void Write(byte[] buffer, int offset, int count) { if ( IsCaptured ) { // copy to holding buffer only - we'll write out later _cacheStream.Write(buffer, 0, count); _cachePointer += count; } // just transform this buffer if (TransformWrite != null) buffer = OnTransformWrite(buffer); if (TransformWriteString != null) buffer = OnTransformWriteStringInternal(buffer); if (!IsOutputDelayed) _stream.Write(buffer, offset, buffer.Length); } } The key features are the events and corresponding OnXXX methods that handle the event hookups, and the Write() and Flush() methods of the stream implementation. All the rest of the members tend to be plain jane passthrough stream implementation code without much consequence. I do love the way Action<t> and Func<T> make it so easy to create the event signatures for the various events – sweet. A few Things to consider Performance Response.Filter is not great for performance in general as it adds another layer of indirection to the ASP.NET output pipeline, and this implementation in particular adds a memory hit as it basically duplicates the response output into the cached memory stream which is necessary since you may have to look at the entire response. If you have large pages in particular this can cause potentially serious memory pressure in your server application. So be careful of wholesale adoption of this (or other) Response.Filters. Make sure to do some performance testing to ensure it’s not killing your app’s performance. Response.Filter works everywhere A few questions came up in comments and discussion as to capturing ALL output hitting the site and – yes you can definitely do that by assigning a Response.Filter inside of a module. If you do this however you’ll want to be very careful and decide which content you actually want to capture especially in IIS 7 which passes ALL content – including static images/CSS etc. through the ASP.NET pipeline. So it is important to filter only on what you’re looking for – like the page extension or maybe more effectively the Response.ContentType. Response.Filter Chaining Originally I thought that filter chaining doesn’t work at all due to a bug in the stream implementation code. But it’s quite possible to assign multiple filters to the Response.Filter property. So the following actually works to both compress the output and apply the transformed content: WebUtils.GZipEncodePage(); ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; However the following does not work resulting in invalid content encoding errors: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; WebUtils.GZipEncodePage(); In other words multiple Response filters can work together but it depends entirely on the implementation whether they can be chained or in which order they can be chained. In this case running the GZip/Deflate stream filters apparently relies on the original content length of the output and chokes when the content is modified. But if attaching the compression first it works fine as unintuitive as that may seem. Resources Download example code Capture Output from ASP.NET Pages © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

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  • Upload File to Windows Azure Blob in Chunks through ASP.NET MVC, JavaScript and HTML5

    - by Shaun
    Originally posted on: http://geekswithblogs.net/shaunxu/archive/2013/07/01/upload-file-to-windows-azure-blob-in-chunks-through-asp.net.aspxMany people are using Windows Azure Blob Storage to store their data in the cloud. Blob storage provides 99.9% availability with easy-to-use API through .NET SDK and HTTP REST. For example, we can store JavaScript files, images, documents in blob storage when we are building an ASP.NET web application on a Web Role in Windows Azure. Or we can store our VHD files in blob and mount it as a hard drive in our cloud service. If you are familiar with Windows Azure, you should know that there are two kinds of blob: page blob and block blob. The page blob is optimized for random read and write, which is very useful when you need to store VHD files. The block blob is optimized for sequential/chunk read and write, which has more common usage. Since we can upload block blob in blocks through BlockBlob.PutBlock, and them commit them as a whole blob with invoking the BlockBlob.PutBlockList, it is very powerful to upload large files, as we can upload blocks in parallel, and provide pause-resume feature. There are many documents, articles and blog posts described on how to upload a block blob. Most of them are focus on the server side, which means when you had received a big file, stream or binaries, how to upload them into blob storage in blocks through .NET SDK.  But the problem is, how can we upload these large files from client side, for example, a browser. This questioned to me when I was working with a Chinese customer to help them build a network disk production on top of azure. The end users upload their files from the web portal, and then the files will be stored in blob storage from the Web Role. My goal is to find the best way to transform the file from client (end user’s machine) to the server (Web Role) through browser. In this post I will demonstrate and describe what I had done, to upload large file in chunks with high speed, and save them as blocks into Windows Azure Blob Storage.   Traditional Upload, Works with Limitation The simplest way to implement this requirement is to create a web page with a form that contains a file input element and a submit button. 1: @using (Html.BeginForm("About", "Index", FormMethod.Post, new { enctype = "multipart/form-data" })) 2: { 3: <input type="file" name="file" /> 4: <input type="submit" value="upload" /> 5: } And then in the backend controller, we retrieve the whole content of this file and upload it in to the blob storage through .NET SDK. We can split the file in blocks and upload them in parallel and commit. The code had been well blogged in the community. 1: [HttpPost] 2: public ActionResult About(HttpPostedFileBase file) 3: { 4: var container = _client.GetContainerReference("test"); 5: container.CreateIfNotExists(); 6: var blob = container.GetBlockBlobReference(file.FileName); 7: var blockDataList = new Dictionary<string, byte[]>(); 8: using (var stream = file.InputStream) 9: { 10: var blockSizeInKB = 1024; 11: var offset = 0; 12: var index = 0; 13: while (offset < stream.Length) 14: { 15: var readLength = Math.Min(1024 * blockSizeInKB, (int)stream.Length - offset); 16: var blockData = new byte[readLength]; 17: offset += stream.Read(blockData, 0, readLength); 18: blockDataList.Add(Convert.ToBase64String(BitConverter.GetBytes(index)), blockData); 19:  20: index++; 21: } 22: } 23:  24: Parallel.ForEach(blockDataList, (bi) => 25: { 26: blob.PutBlock(bi.Key, new MemoryStream(bi.Value), null); 27: }); 28: blob.PutBlockList(blockDataList.Select(b => b.Key).ToArray()); 29:  30: return RedirectToAction("About"); 31: } This works perfect if we selected an image, a music or a small video to upload. But if I selected a large file, let’s say a 6GB HD-movie, after upload for about few minutes the page will be shown as below and the upload will be terminated. In ASP.NET there is a limitation of request length and the maximized request length is defined in the web.config file. It’s a number which less than about 4GB. So if we want to upload a really big file, we cannot simply implement in this way. Also, in Windows Azure, a cloud service network load balancer will terminate the connection if exceed the timeout period. From my test the timeout looks like 2 - 3 minutes. Hence, when we need to upload a large file we cannot just use the basic HTML elements. Besides the limitation mentioned above, the simple HTML file upload cannot provide rich upload experience such as chunk upload, pause and pause-resume. So we need to find a better way to upload large file from the client to the server.   Upload in Chunks through HTML5 and JavaScript In order to break those limitation mentioned above we will try to upload the large file in chunks. This takes some benefit to us such as - No request size limitation: Since we upload in chunks, we can define the request size for each chunks regardless how big the entire file is. - No timeout problem: The size of chunks are controlled by us, which means we should be able to make sure request for each chunk upload will not exceed the timeout period of both ASP.NET and Windows Azure load balancer. It was a big challenge to upload big file in chunks until we have HTML5. There are some new features and improvements introduced in HTML5 and we will use them to implement our solution.   In HTML5, the File interface had been improved with a new method called “slice”. It can be used to read part of the file by specifying the start byte index and the end byte index. For example if the entire file was 1024 bytes, file.slice(512, 768) will read the part of this file from the 512nd byte to 768th byte, and return a new object of interface called "Blob”, which you can treat as an array of bytes. In fact,  a Blob object represents a file-like object of immutable, raw data. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system. For more information about the Blob please refer here. File and Blob is very useful to implement the chunk upload. We will use File interface to represent the file the user selected from the browser and then use File.slice to read the file in chunks in the size we wanted. For example, if we wanted to upload a 10MB file with 512KB chunks, then we can read it in 512KB blobs by using File.slice in a loop.   Assuming we have a web page as below. User can select a file, an input box to specify the block size in KB and a button to start upload. 1: <div> 2: <input type="file" id="upload_files" name="files[]" /><br /> 3: Block Size: <input type="number" id="block_size" value="512" name="block_size" />KB<br /> 4: <input type="button" id="upload_button_blob" name="upload" value="upload (blob)" /> 5: </div> Then we can have the JavaScript function to upload the file in chunks when user clicked the button. 1: <script type="text/javascript"> 1: 2: $(function () { 3: $("#upload_button_blob").click(function () { 4: }); 5: });</script> Firstly we need to ensure the client browser supports the interfaces we are going to use. Just try to invoke the File, Blob and FormData from the “window” object. If any of them is “undefined” the condition result will be “false” which means your browser doesn’t support these premium feature and it’s time for you to get your browser updated. FormData is another new feature we are going to use in the future. It could generate a temporary form for us. We will use this interface to create a form with chunk and associated metadata when invoked the service through ajax. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: if (window.File && window.Blob && window.FormData) { 4: alert("Your brwoser is awesome, let's rock!"); 5: } 6: else { 7: alert("Oh man plz update to a modern browser before try is cool stuff out."); 8: return; 9: } 10: }); Each browser supports these interfaces by their own implementation and currently the Blob, File and File.slice are supported by Chrome 21, FireFox 13, IE 10, Opera 12 and Safari 5.1 or higher. After that we worked on the files the user selected one by one since in HTML5, user can select multiple files in one file input box. 1: var files = $("#upload_files")[0].files; 2: for (var i = 0; i < files.length; i++) { 3: var file = files[i]; 4: var fileSize = file.size; 5: var fileName = file.name; 6: } Next, we calculated the start index and end index for each chunks based on the size the user specified from the browser. We put them into an array with the file name and the index, which will be used when we upload chunks into Windows Azure Blob Storage as blocks since we need to specify the target blob name and the block index. At the same time we will store the list of all indexes into another variant which will be used to commit blocks into blob in Azure Storage once all chunks had been uploaded successfully. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10:  11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: var blockSizeInKB = $("#block_size").val(); 14: var blockSize = blockSizeInKB * 1024; 15: var blocks = []; 16: var offset = 0; 17: var index = 0; 18: var list = ""; 19: while (offset < fileSize) { 20: var start = offset; 21: var end = Math.min(offset + blockSize, fileSize); 22:  23: blocks.push({ 24: name: fileName, 25: index: index, 26: start: start, 27: end: end 28: }); 29: list += index + ","; 30:  31: offset = end; 32: index++; 33: } 34: } 35: }); Now we have all chunks’ information ready. The next step should be upload them one by one to the server side, and at the server side when received a chunk it will upload as a block into Blob Storage, and finally commit them with the index list through BlockBlobClient.PutBlockList. But since all these invokes are ajax calling, which means not synchronized call. So we need to introduce a new JavaScript library to help us coordinate the asynchronize operation, which named “async.js”. You can download this JavaScript library here, and you can find the document here. I will not explain this library too much in this post. We will put all procedures we want to execute as a function array, and pass into the proper function defined in async.js to let it help us to control the execution sequence, in series or in parallel. Hence we will define an array and put the function for chunk upload into this array. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4:  5: // start to upload each files in chunks 6: var files = $("#upload_files")[0].files; 7: for (var i = 0; i < files.length; i++) { 8: var file = files[i]; 9: var fileSize = file.size; 10: var fileName = file.name; 11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: ... ... 14:  15: // define the function array and push all chunk upload operation into this array 16: blocks.forEach(function (block) { 17: putBlocks.push(function (callback) { 18: }); 19: }); 20: } 21: }); 22: }); As you can see, I used File.slice method to read each chunks based on the start and end byte index we calculated previously, and constructed a temporary HTML form with the file name, chunk index and chunk data through another new feature in HTML5 named FormData. Then post this form to the backend server through jQuery.ajax. This is the key part of our solution. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: blocks.forEach(function (block) { 15: putBlocks.push(function (callback) { 16: // load blob based on the start and end index for each chunks 17: var blob = file.slice(block.start, block.end); 18: // put the file name, index and blob into a temporary from 19: var fd = new FormData(); 20: fd.append("name", block.name); 21: fd.append("index", block.index); 22: fd.append("file", blob); 23: // post the form to backend service (asp.net mvc controller action) 24: $.ajax({ 25: url: "/Home/UploadInFormData", 26: data: fd, 27: processData: false, 28: contentType: "multipart/form-data", 29: type: "POST", 30: success: function (result) { 31: if (!result.success) { 32: alert(result.error); 33: } 34: callback(null, block.index); 35: } 36: }); 37: }); 38: }); 39: } 40: }); Then we will invoke these functions one by one by using the async.js. And once all functions had been executed successfully I invoked another ajax call to the backend service to commit all these chunks (blocks) as the blob in Windows Azure Storage. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.series(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); That’s all in the client side. The outline of our logic would be - Calculate the start and end byte index for each chunks based on the block size. - Defined the functions of reading the chunk form file and upload the content to the backend service through ajax. - Execute the functions defined in previous step with “async.js”. - Commit the chunks by invoking the backend service in Windows Azure Storage finally.   Save Chunks as Blocks into Blob Storage In above we finished the client size JavaScript code. It uploaded the file in chunks to the backend service which we are going to implement in this step. We will use ASP.NET MVC as our backend service, and it will receive the chunks, upload into Windows Azure Bob Storage in blocks, then finally commit as one blob. As in the client side we uploaded chunks by invoking the ajax call to the URL "/Home/UploadInFormData", I created a new action under the Index controller and it only accepts HTTP POST request. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: } 8: catch (Exception e) 9: { 10: error = e.ToString(); 11: } 12:  13: return new JsonResult() 14: { 15: Data = new 16: { 17: success = string.IsNullOrWhiteSpace(error), 18: error = error 19: } 20: }; 21: } Then I retrieved the file name, index and the chunk content from the Request.Form object, which was passed from our client side. And then, used the Windows Azure SDK to create a blob container (in this case we will use the container named “test”.) and create a blob reference with the blob name (same as the file name). Then uploaded the chunk as a block of this blob with the index, since in Blob Storage each block must have an index (ID) associated with so that finally we can put all blocks as one blob by specifying their block ID list. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var index = int.Parse(Request.Form["index"]); 9: var file = Request.Files[0]; 10: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 11:  12: var container = _client.GetContainerReference("test"); 13: container.CreateIfNotExists(); 14: var blob = container.GetBlockBlobReference(name); 15: blob.PutBlock(id, file.InputStream, null); 16: } 17: catch (Exception e) 18: { 19: error = e.ToString(); 20: } 21:  22: return new JsonResult() 23: { 24: Data = new 25: { 26: success = string.IsNullOrWhiteSpace(error), 27: error = error 28: } 29: }; 30: } Next, I created another action to commit the blocks into blob once all chunks had been uploaded. Similarly, I retrieved the blob name from the Request.Form. I also retrieved the chunks ID list, which is the block ID list from the Request.Form in a string format, split them as a list, then invoked the BlockBlob.PutBlockList method. After that our blob will be shown in the container and ready to be download. 1: [HttpPost] 2: public JsonResult Commit() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var list = Request.Form["list"]; 9: var ids = list 10: .Split(',') 11: .Where(id => !string.IsNullOrWhiteSpace(id)) 12: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 13: .ToArray(); 14:  15: var container = _client.GetContainerReference("test"); 16: container.CreateIfNotExists(); 17: var blob = container.GetBlockBlobReference(name); 18: blob.PutBlockList(ids); 19: } 20: catch (Exception e) 21: { 22: error = e.ToString(); 23: } 24:  25: return new JsonResult() 26: { 27: Data = new 28: { 29: success = string.IsNullOrWhiteSpace(error), 30: error = error 31: } 32: }; 33: } Now we finished all code we need. The whole process of uploading would be like this below. Below is the full client side JavaScript code. 1: <script type="text/javascript" src="~/Scripts/async.js"></script> 2: <script type="text/javascript"> 3: $(function () { 4: $("#upload_button_blob").click(function () { 5: // assert the browser support html5 6: if (window.File && window.Blob && window.FormData) { 7: alert("Your brwoser is awesome, let's rock!"); 8: } 9: else { 10: alert("Oh man plz update to a modern browser before try is cool stuff out."); 11: return; 12: } 13:  14: // start to upload each files in chunks 15: var files = $("#upload_files")[0].files; 16: for (var i = 0; i < files.length; i++) { 17: var file = files[i]; 18: var fileSize = file.size; 19: var fileName = file.name; 20:  21: // calculate the start and end byte index for each blocks(chunks) 22: // with the index, file name and index list for future using 23: var blockSizeInKB = $("#block_size").val(); 24: var blockSize = blockSizeInKB * 1024; 25: var blocks = []; 26: var offset = 0; 27: var index = 0; 28: var list = ""; 29: while (offset < fileSize) { 30: var start = offset; 31: var end = Math.min(offset + blockSize, fileSize); 32:  33: blocks.push({ 34: name: fileName, 35: index: index, 36: start: start, 37: end: end 38: }); 39: list += index + ","; 40:  41: offset = end; 42: index++; 43: } 44:  45: // define the function array and push all chunk upload operation into this array 46: var putBlocks = []; 47: blocks.forEach(function (block) { 48: putBlocks.push(function (callback) { 49: // load blob based on the start and end index for each chunks 50: var blob = file.slice(block.start, block.end); 51: // put the file name, index and blob into a temporary from 52: var fd = new FormData(); 53: fd.append("name", block.name); 54: fd.append("index", block.index); 55: fd.append("file", blob); 56: // post the form to backend service (asp.net mvc controller action) 57: $.ajax({ 58: url: "/Home/UploadInFormData", 59: data: fd, 60: processData: false, 61: contentType: "multipart/form-data", 62: type: "POST", 63: success: function (result) { 64: if (!result.success) { 65: alert(result.error); 66: } 67: callback(null, block.index); 68: } 69: }); 70: }); 71: }); 72:  73: // invoke the functions one by one 74: // then invoke the commit ajax call to put blocks into blob in azure storage 75: async.series(putBlocks, function (error, result) { 76: var data = { 77: name: fileName, 78: list: list 79: }; 80: $.post("/Home/Commit", data, function (result) { 81: if (!result.success) { 82: alert(result.error); 83: } 84: else { 85: alert("done!"); 86: } 87: }); 88: }); 89: } 90: }); 91: }); 92: </script> And below is the full ASP.NET MVC controller code. 1: public class HomeController : Controller 2: { 3: private CloudStorageAccount _account; 4: private CloudBlobClient _client; 5:  6: public HomeController() 7: : base() 8: { 9: _account = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("DataConnectionString")); 10: _client = _account.CreateCloudBlobClient(); 11: } 12:  13: public ActionResult Index() 14: { 15: ViewBag.Message = "Modify this template to jump-start your ASP.NET MVC application."; 16:  17: return View(); 18: } 19:  20: [HttpPost] 21: public JsonResult UploadInFormData() 22: { 23: var error = string.Empty; 24: try 25: { 26: var name = Request.Form["name"]; 27: var index = int.Parse(Request.Form["index"]); 28: var file = Request.Files[0]; 29: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 30:  31: var container = _client.GetContainerReference("test"); 32: container.CreateIfNotExists(); 33: var blob = container.GetBlockBlobReference(name); 34: blob.PutBlock(id, file.InputStream, null); 35: } 36: catch (Exception e) 37: { 38: error = e.ToString(); 39: } 40:  41: return new JsonResult() 42: { 43: Data = new 44: { 45: success = string.IsNullOrWhiteSpace(error), 46: error = error 47: } 48: }; 49: } 50:  51: [HttpPost] 52: public JsonResult Commit() 53: { 54: var error = string.Empty; 55: try 56: { 57: var name = Request.Form["name"]; 58: var list = Request.Form["list"]; 59: var ids = list 60: .Split(',') 61: .Where(id => !string.IsNullOrWhiteSpace(id)) 62: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 63: .ToArray(); 64:  65: var container = _client.GetContainerReference("test"); 66: container.CreateIfNotExists(); 67: var blob = container.GetBlockBlobReference(name); 68: blob.PutBlockList(ids); 69: } 70: catch (Exception e) 71: { 72: error = e.ToString(); 73: } 74:  75: return new JsonResult() 76: { 77: Data = new 78: { 79: success = string.IsNullOrWhiteSpace(error), 80: error = error 81: } 82: }; 83: } 84: } And if we selected a file from the browser we will see our application will upload chunks in the size we specified to the server through ajax call in background, and then commit all chunks in one blob. Then we can find the blob in our Windows Azure Blob Storage.   Optimized by Parallel Upload In previous example we just uploaded our file in chunks. This solved the problem that ASP.NET MVC request content size limitation as well as the Windows Azure load balancer timeout. But it might introduce the performance problem since we uploaded chunks in sequence. In order to improve the upload performance we could modify our client side code a bit to make the upload operation invoked in parallel. The good news is that, “async.js” library provides the parallel execution function. If you remembered the code we invoke the service to upload chunks, it utilized “async.series” which means all functions will be executed in sequence. Now we will change this code to “async.parallel”. This will invoke all functions in parallel. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallel(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); In this way all chunks will be uploaded to the server side at the same time to maximize the bandwidth usage. This should work if the file was not very large and the chunk size was not very small. But for large file this might introduce another problem that too many ajax calls are sent to the server at the same time. So the best solution should be, upload the chunks in parallel with maximum concurrency limitation. The code below specified the concurrency limitation to 4, which means at the most only 4 ajax calls could be invoked at the same time. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallelLimit(putBlocks, 4, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: });   Summary In this post we discussed how to upload files in chunks to the backend service and then upload them into Windows Azure Blob Storage in blocks. We focused on the frontend side and leverage three new feature introduced in HTML 5 which are - File.slice: Read part of the file by specifying the start and end byte index. - Blob: File-like interface which contains the part of the file content. - FormData: Temporary form element that we can pass the chunk alone with some metadata to the backend service. Then we discussed the performance consideration of chunk uploading. Sequence upload cannot provide maximized upload speed, but the unlimited parallel upload might crash the browser and server if too many chunks. So we finally came up with the solution to upload chunks in parallel with the concurrency limitation. We also demonstrated how to utilize “async.js” JavaScript library to help us control the asynchronize call and the parallel limitation.   Regarding the chunk size and the parallel limitation value there is no “best” value. You need to test vary composition and find out the best one for your particular scenario. It depends on the local bandwidth, client machine cores and the server side (Windows Azure Cloud Service Virtual Machine) cores, memory and bandwidth. Below is one of my performance test result. The client machine was Windows 8 IE 10 with 4 cores. I was using Microsoft Cooperation Network. The web site was hosted on Windows Azure China North data center (in Beijing) with one small web role (1.7GB 1 core CPU, 1.75GB memory with 100Mbps bandwidth). The test cases were - Chunk size: 512KB, 1MB, 2MB, 4MB. - Upload Mode: Sequence, parallel (unlimited), parallel with limit (4 threads, 8 threads). - Chunk Format: base64 string, binaries. - Target file: 100MB. - Each case was tested 3 times. Below is the test result chart. Some thoughts, but not guidance or best practice: - Parallel gets better performance than series. - No significant performance improvement between parallel 4 threads and 8 threads. - Transform with binaries provides better performance than base64. - In all cases, chunk size in 1MB - 2MB gets better performance.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • Design by Contract with Microsoft .Net Code Contract

    - by Fredrik N
    I have done some talks on different events and summits about Defensive Programming and Design by Contract, last time was at Cornerstone’s Developer Summit 2010. Next time will be at SweNug (Sweden .Net User Group). I decided to write a blog post about of some stuffs I was talking about. Users are a terrible thing! Protect your self from them ”Human users have a gift for doing the worst possible thing at the worst possible time.” – Michael T. Nygard, Release It! The kind of users Michael T. Nygard are talking about is the users of a system. We also have users that uses our code, the users I’m going to focus on is the users of our code. Me and you and another developers. “Any fool can write code that a computer can understand. Good programmers write code that humans can understand.” – Martin Fowler Good programmers also writes code that humans know how to use, good programmers also make sure software behave in a predictable manner despise inputs or user actions. Design by Contract   Design by Contract (DbC) is a way for us to make a contract between us (the code writer) and the users of our code. It’s about “If you give me this, I promise to give you this”. It’s not about business validations, that is something completely different that should be part of the domain model. DbC is to make sure the users of our code uses it in a correct way, and that we can rely on the contract and write code in a way where we know that the users will follow the contract. It will make it much easier for us to write code with a contract specified. Something like the following code is something we may see often: public void DoSomething(Object value) { value.DoIKnowThatICanDoThis(); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Where “value” can be uses directly or passed to other methods and later be used. What some of us can easily forget here is that the “value” can be “null”. We will probably not passing a null value, but someone else that uses our code maybe will do it. I think most of you (including me) have passed “null” into a method because you don’t know if the argument need to be specified to a valid value etc. I bet most of you also have got the “Null reference exception”. Sometimes this “Null reference exception” can be hard and take time to fix, because we need to search among our code to see where the “null” value was passed in etc. Wouldn’t it be much better if we can as early as possible specify that the value can’t not be null, so the users of our code also know it when the users starts to use our code, and before run time execution of the code? This is where DbC comes into the picture. We can use DbC to specify what we need, and by doing so we can rely on the contract when we write our code. So the code above can actually use the DoIKnowThatICanDoThis() method on the value object without being worried that the “value” can be null. The contract between the users of the code and us writing the code, says that the “value” can’t be null.   Pre- and Postconditions   When working with DbC we are specifying pre- and postconditions.  Precondition is a condition that should be met before a query or command is executed. An example of a precondition is: “The Value argument of the method can’t be null”, and we make sure the “value” isn’t null before the method is called. Postcondition is a condition that should be met when a command or query is completed, a postcondition will make sure the result is correct. An example of a postconditon is “The method will return a list with at least 1 item”. Commands an Quires When using DbC, we need to know what a Command and a Query is, because some principles that can be good to follow are based on commands and queries. A Command is something that will not return anything, like the SQL’s CREATE, UPDATE and DELETE. There are two kinds of Commands when using DbC, the Creation commands (for example a Constructor), and Others. Others can for example be a Command to add a value to a list, remove or update a value etc. //Creation commands public Stack(int size) //Other commands public void Push(object value); public void Remove(); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   A Query, is something that will return something, for example an Attribute, Property or a Function, like the SQL’s SELECT.   There are two kinds of Queries, the Basic Queries  (Quires that aren’t based on another queries), and the Derived Queries, queries that is based on another queries. Here is an example of queries of a Stack: //Basic Queries public int Count; public object this[int index] { get; } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } To understand about some principles that are good to follow when using DbC, we need to know about the Commands and different Queries. The 6 Principles When working with DbC, it’s advisable to follow some principles to make it easier to define and use contracts. The following DbC principles are: Separate commands and queries. Separate basic queries from derived queries. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries. For each command, write a postcondition that specifies the value of every basic query. For every query and command, decide on a suitable precondition. Write invariants to define unchanging properties of objects. Before I will write about each of them I want you to now that I’m going to use .Net 4.0 Code Contract. I will in the rest of the post uses a simple Stack (Yes I know, .Net already have a Stack class) to give you the basic understanding about using DbC. A Stack is a data structure where the first item in, will be the first item out. Here is a basic implementation of a Stack where not contract is specified yet: public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } //Is related to Count and this[] Query public object Top() { return this[Count]; } //Creation commands public Stack(uint size) { Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { this[++Count] = value; } public void Remove() { this[Count] = null; Count--; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The Stack is implemented in a way to demonstrate the use of Code Contract in a simple way, the implementation may not look like how you would implement it, so don’t think this is the perfect Stack implementation, only used for demonstration.   Before I will go deeper into the principles I will simply mention how we can use the .Net Code Contract. I mention before about pre- and postcondition, is about “Require” something and to “Ensure” something. When using Code Contract, we will use a static class called “Contract” and is located in he “System.Diagnostics.Contracts” namespace. The contract must be specified at the top or our member statement block. To specify a precondition with Code Contract we uses the Contract.Requires method, and to specify a postcondition, we uses the Contract.Ensure method. Here is an example where both a pre- and postcondition are used: public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The contract above requires that the Count is greater than 0, if not we can’t get the item at the Top of a Stack. We also Ensures that the results (By using the Contract.Result method, we can specify a postcondition that will check if the value returned from a method is correct) of the Top query is equal to this[Count].   1. Separate Commands and Queries   When working with DbC, it’s important to separate Command and Quires. A method should either be a command that performs an Action, or returning information to the caller, not both. By asking a question the answer shouldn’t be changed. The following is an example of a Command and a Query of a Stack: public void Push(object value) public object Top() .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The Push is a command and will not return anything, just add a value to the Stack, the Top is a query to get the item at the top of the stack.   2. Separate basic queries from derived queries There are two different kinds of queries,  the basic queries that doesn’t rely on another queries, and derived queries that uses a basic query. The “Separate basic queries from derived queries” principle is about about that derived queries can be specified in terms of basic queries. So this principles is more about recognizing that a query is a derived query or a basic query. It will then make is much easier to follow the other principles. The following code shows a basic query and a derived query: //Basic Queries public uint Count; //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   We can see that IsEmpty will use the Count query, and that makes the IsEmpty a Derived query.   3. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries.   When the derived query is recognize we can follow the 3ed principle. For each derived query, we can create a postcondition that specifies what result our derived query will return in terms of one or more basic queries. Remember that DbC is about contracts between the users of the code and us writing the code. So we can’t use demand that the users will pass in a valid value, we must also ensure that we will give the users what the users wants, when the user is following our contract. The IsEmpty query of the Stack will use a Count query and that will make the IsEmpty a Derived query, so we should now write a postcondition that specified what results will be returned, in terms of using a basic query and in this case the Count query, //Basic Queries public uint Count; //Derived Queries public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } The Contract.Ensures is used to create a postcondition. The above code will make sure that the results of the IsEmpty (by using the Contract.Result to get the result of the IsEmpty method) is correct, that will say that the IsEmpty will be either true or false based on Count is equal to 0 or not. The postcondition are using a basic query, so the IsEmpty is now following the 3ed principle. We also have another Derived Query, the Top query, it will also need a postcondition and it uses all basic queries. The Result of the Top method must be the same value as the this[] query returns. //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count and this[] Query public object Top() { Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   4. For each command, write a postcondition that specifies the value of every basic query.   For each command we will create a postconditon that specifies the value of basic queries. If we look at the Stack implementation we will have three Commands, one Creation command, the Constructor, and two others commands, Push and Remove. Those commands need a postcondition and they should include basic query to follow the 4th principle. //Creation commands public Stack(uint size) { Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   As you can see the Create command will Ensures that Count will be 0 when the Stack is created, when a Stack is created there shouldn’t be any items in the stack. The Push command will take a value and put it into the Stack, when an item is pushed into the Stack, the Count need to be increased to know the number of items added to the Stack, and we must also make sure the item is really added to the Stack. The postconditon of the Push method will make sure the that old value of the Count (by using the Contract.OldValue we can get the value a Query has before the method is called)  plus 1 will be equal to the Count query, this is the way we can ensure that the Push will increase the Count with one. We also make sure the this[] query will now contain the item we pushed into the Stack. The Remove method must make sure the Count is decreased by one when the top item is removed from the Stack. The Commands is now following the 4th principle, where each command now have a postcondition that used the value of basic queries. Note: The principle says every basic Query, the Remove only used one Query the Count, it’s because this command can’t use the this[] query because an item is removed, so the only way to make sure an item is removed is to just use the Count query, so the Remove will still follow the principle.   5. For every query and command, decide on a suitable precondition.   We have now focused only on postcondition, now time for some preconditons. The 5th principle is about deciding a suitable preconditon for every query and command. If we starts to look at one of our basic queries (will not go through all Queries and commands here, just some of them) the this[] query, we can’t pass an index that is lower then 1 (.Net arrays and list are zero based, but not the stack in this blog post ;)) and the index can’t be lesser than the number of items in the stack. So here we will need a preconditon. public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Think about the Contract as an documentation about how to use the code in a correct way, so if the contract could be specified elsewhere (not part of the method body), we could simply write “return _array[index]” and there is no need to check if index is greater or lesser than Count, because that is specified in a “contract”. The implementation of Code Contract, requires that the contract is specified in the code. As a developer I would rather have this contract elsewhere (Like Spec#) or implemented in a way Eiffel uses it as part of the language. Now when we have looked at one Query, we can also look at one command, the Remove command (You can see the whole implementation of the Stack at the end of this blog post, where precondition is added to more queries and commands then what I’m going to show in this section). We can only Remove an item if the Count is greater than 0. So we can write a precondition that will require that Count must be greater than 0. public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   6. Write invariants to define unchanging properties of objects.   The last principle is about making sure the object are feeling great! This is done by using invariants. When using Code Contract we can specify invariants by adding a method with the attribute ContractInvariantMethod, the method must be private or public and can only contains calls to Contract.Invariant. To make sure the Stack feels great, the Stack must have 0 or more items, the Count can’t never be a negative value to make sure each command and queries can be used of the Stack. Here is our invariant for the Stack object: [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The ObjectInvariant method will be called every time after a Query or Commands is called. Here is the full example using Code Contract:   public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } set { Contract.Requires(index >= 1); Contract.Requires(index <= Count); _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } //Is related to Count and this[] Query public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } //Creation commands public Stack(uint size) { Contract.Requires(size > 0); Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Requires(value != null); Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Summary By using Design By Contract we can make sure the users are using our code in a correct way, and we must also make sure the users will get the expected results when they uses our code. This can be done by specifying contracts. To make it easy to use Design By Contract, some principles may be good to follow like the separation of commands an queries. With .Net 4.0 we can use the Code Contract feature to specify contracts.

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  • Red Gate Coder interviews: Alex Davies

    - by Michael Williamson
    Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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  • Oracle Support Master Note for Troubleshooting Advanced Queuing and Oracle Streams Propagation Issues (Doc ID 233099.1)

    - by faye.todd(at)oracle.com
    Master Note for Troubleshooting Advanced Queuing and Oracle Streams Propagation Issues (Doc ID 233099.1) Copyright (c) 2010, Oracle Corporation. All Rights Reserved. In this Document  Purpose  Last Review Date  Instructions for the Reader  Troubleshooting Details     1. Scope and Application      2. Definitions and Classifications     3. How to Use This Guide     4. Basic AQ Propagation Troubleshooting     5. Additional Troubleshooting Steps for AQ Propagation of User-Enqueued and Dequeued Messages     6. Additional Troubleshooting Steps for Propagation in an Oracle Streams Environment     7. Performance Issues  References Applies to: Oracle Server - Enterprise Edition - Version: 8.1.7.0 to 11.2.0.2 - Release: 8.1.7 to 11.2Information in this document applies to any platform. Purpose This document presents a step-by-step methodology for troubleshooting and resolving problems with Advanced Queuing Propagation in both Streams and basic Advanced Queuing environments. It also serves as a master reference for other more specific notes on Oracle Streams Propagation and Advanced Queuing Propagation issues. Last Review Date December 20, 2010 Instructions for the Reader A Troubleshooting Guide is provided to assist in debugging a specific issue. When possible, diagnostic tools are included in the document to assist in troubleshooting. Troubleshooting Details 1. Scope and Application This note is intended for Database Administrators of Oracle databases where issues are being encountered with propagating messages between advanced queues, whether the queues are used for user-created messaging systems or for Oracle Streams. It contains troubleshooting steps and links to notes for further problem resolution.It can also be used a template to document a problem when it is necessary to engage Oracle Support Services. Knowing what is NOT happening can frequently speed up the resolution process by focusing solely on the pertinent problem area. This guide is divided into five parts: Section 2: Definitions and Classifications (discusses the different types and features of propagations possible - helpful for understanding the rest of the guide) Section 3: How to Use this Guide (to be used as a start part for determining the scope of the problem and what sections to consult) Section 4. Basic AQ propagation troubleshooting (applies to both AQ propagation of user enqueued and dequeued messages as well as Oracle Streams propagations) Section 5. Additional troubleshooting steps for AQ propagation of user enqueued and dequeued messages Section 6. Additional troubleshooting steps for Oracle Streams propagation Section 7. Performance issues 2. Definitions and Classifications Given the potential scope of issues that can be encountered with AQ propagation, the first recommended step is to do some basic diagnosis to determine the type of problem that is being encountered. 2.1. What Type of Propagation is Being Used? 2.1.1. Buffered Messaging For an advanced queue, messages can be maintained on disk (persistent messaging) or in memory (buffered messaging). To determine if a queue is buffered or not, reference the GV_$BUFFERED_QUEUES view. If the queue does not appear in this view, it is persistent. 2.1.2. Propagation mode - queue-to-dblink vs queue-to-queue As of 10.2, an AQ propagation can also be defined as queue-to-dblink, or queue-to-queue: queue-to-dblink: The propagation delivers messages or events from the source queue to all subscribing queues at the destination database identified by the dblink. A single propagation schedule is used to propagate messages to all subscribing queues. Hence any changes made to this schedule will affect message delivery to all the subscribing queues. This mode does not support multiple propagations from the same source queue to the same target database. queue-to-queue: Added in 10.2, this propagation mode delivers messages or events from the source queue to a specific destination queue identified on the database link. This allows the user to have fine-grained control on the propagation schedule for message delivery. This new propagation mode also supports transparent failover when propagating to a destination Oracle RAC system. With queue-to-queue propagation, you are no longer required to re-point a database link if the owner instance of the queue fails on Oracle RAC. This mode supports multiple propagations to the same target database if the target queues are different. The default is queue-to-dblink. To verify if queue-to-queue propagation is being used, in non-Streams environments query DBA_QUEUE_SCHEDULES.DESTINATION - if a remote queue is listed along with the remote database link, then queue-to-queue propagation is being used. For Streams environments, the DBA_PROPAGATION.QUEUE_TO_QUEUE column can be checked.See the following note for a method to switch between the two modes:Document 827473.1 How to alter propagation from queue-to-queue to queue-to-dblink 2.1.3. Combined Capture and Apply (CCA) for Streams In 11g Oracle Streams environments, an optimization called Combined Capture and Apply (CCA) is implemented by default when possible. Although a propagation is configured in this case, Streams does not use it; instead it passes information directly from capture to an apply receiver. To see if CCA is in use: COLUMN CAPTURE_NAME HEADING 'Capture Name' FORMAT A30COLUMN OPTIMIZATION HEADING 'CCA Mode?' FORMAT A10SELECT CAPTURE_NAME, DECODE(OPTIMIZATION,0, 'No','Yes') OPTIMIZATIONFROM V$STREAMS_CAPTURE; Also, see the following note:Document 463820.1 Streams Combined Capture and Apply in 11g 2.2. Queue Table Compatibility There are three types of queue table compatibility. In more recent databases, queue tables may be present in all three modes of compatibility: 8.0 - earliest version, deprecated in 10.2 onwards 8.1 - support added for RAC, asynchronous notification, secure queues, queue level access control, rule-based subscribers, separate storage of history information 10.0 - if the database is in 10.1-compatible mode, then the default value for queue table compatibility is 10.0 2.3. Single vs Multiple Consumer Queue Tables If more than one recipient can dequeue a message from a queue, then its queue table is multiple consumer. You can propagate messages from a multiple-consumer queue to a single-consumer queue. Propagation from a single-consumer queue to a multiple-consumer queue is not possible. 3. How to Use This Guide 3.1. Are Messages Being Propagated at All, or is the Propagation Just Slow? Run the following query on the source database for the propagation (assuming that it is running): select TOTAL_NUMBER from DBA_QUEUE_SCHEDULES where QNAME='<source_queue_name>'; If TOTAL_NUMBER is increasing, then propagation is most likely functioning, although it may be slow. For performance issues, see Section 7. 3.2. Propagation Between Persistent User-Created Queues See Sections 4 and 5 (and optionally Section 6 if performance is an issue). 3.3. Propagation Between Buffered User-Created Queues See Sections 4, 5, and 6 (and optionally Section 7 if performance is an issue). 3.4. Propagation between Oracle Streams Queues (without Combined Capture and Apply (CCA) Optimization) See Sections 4 and 6 (and optionally Section 7 if performance is an issue). 3.5. Propagation between Oracle Streams Queues (with Combined Capture and Apply (CCA) Optimization) Although an AQ propagation is not used directly in this case, some characteristics of the message transfer are inferred from the propagation parameters used. Some parts of Sections 4 and 6 still apply. 3.6. Messaging Gateway Propagations This note does not apply to Messaging Gateway propagations. 4. Basic AQ Propagation Troubleshooting 4.1. Double-check Your Code Make sure that you are consistent in your usage of the database link(s) names, queue names, etc. It may be useful to plot a diagram of which queues are connected via which database links to make sure that the logical structure is correct. 4.2. Verify that Job Queue Processes are Running 4.2.1. Versions 10.2 and Lower - DBA_JOBS Package For versions 10.2 and lower, a scheduled propagation is managed by DBMS_JOB package. The propagation is performed by job queue process background processes. Therefore we need to verify that there are sufficient processes available for the propagation process. We should have at least 4 job queue processes running and preferably more depending on the number of other jobs running in the database. It should be noted that for AQ specific work, AQ will only ever use half of the job queue processes available.An issue caused by an inadequate job queue processes parameter setting is described in the following note:Document 298015.1 Kwqjswproc:Excep After Loop: Assigning To Self 4.2.1.1. Job Queue Processes in Initalization Parameter File The parameter JOB_QUEUE_PROCESSES in the init.ora/spfile should be > 0. The value can be changed dynamically via connect / as sysdbaalter system set JOB_QUEUE_PROCESSES=10; 4.2.1.2. Job Queue Processes in Memory The following command will show how many job queue processes are currentlyin use by this instance (this may be different than what is in the init.ora/spfile): connect / as sysdbashow parameter job; 4.2.1.3. OS PIDs Corresponding to Job Queue Processes Identify the operating system process ids (spids) of job queue processes involved in propagation via select p.SPID, p.PROGRAM from V$PROCESS p, DBA_JOBS_RUNNING jr, V$SESSION s, DBA_JOBS j where s.SID=jr.SID and s.PADDR=p.ADDR and jr.JOB=j.JOBand j.WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%'; and these SPIDs can be used to check at the operating system level that they exist.In 8i a job queue process will have a name similar to: ora_snp1_<instance_name>.In 9i onwards you will see a coordinator process: ora_cjq0_ and multiple slave processes: ora_jnnn_<instance_name>, where nnn is an integer between 1 and 999. 4.2.2. Version 11.1 and Above - Oracle Scheduler In version 11.1 and above, Oracle Scheduler is used to perform AQ and Streams propagations. Oracle Scheduler automatically tunes the number of slave processes for these jobs based on the load on the computer system, and the JOB_QUEUE_PROCESSES initialization parameter is only used to specify the maximum number of slave processes. Therefore, the JOB_QUEUE_PROCESSES initialization parameter does not need to be set (it defaults to a very high number), unless you want to limit the number of slaves that can be created. If JOB_QUEUE_PROCESSES = 0, no propagation jobs will run.See the following note for a discussion of Oracle Streams 11g and Oracle Scheduler:Document 1083608.1 11g Streams and Oracle Scheduler 4.2.2.1. Job Queue Processes in Initalization Parameter File The parameter JOB_QUEUE_PROCESSES in the init.ora/spfile should be > 0, and preferably be left at its default value. The value can be changed dynamically via connect / as sysdbaalter system set JOB_QUEUE_PROCESSES=10; To set the JOB_QUEUE_PROCESSES parameter to its default value, run: connect / as sysdbaalter system reset JOB_QUEUE_PROCESSES; and then bounce the instance. 4.2.2.2. Job Queue Processes in Memory The following command will show how many job queue processes are currently in use by this instance (this may be different than what is in the init.ora/spfile): connect / as sysdbashow parameter job; 4.2.2.3. OS PIDs Corresponding to Job Queue Processes Identify the operating system process ids (SPIDs) of job queue processes involved in propagation via col PROGRAM for a30select p.SPID, p.PROGRAM, j.JOB_namefrom v$PROCESS p, DBA_SCHEDULER_RUNNING_JOBS jr, V$SESSION s, DBA_SCHEDULER_JOBS j where s.SID=jr.SESSION_ID and s.PADDR=p.ADDRand jr.JOB_name=j.JOB_NAME and j.JOB_NAME like '%AQ_JOB$_%'; and these SPIDs can be used to check at the operating system level that they exist.You will see a coordinator process: ora_cjq0_ and multiple slave processes: ora_jnnn_<instance_name>, where nnn is an integer between 1 and 999. 4.3. Check the Alert Log and Any Associated Trace Files The first place to check for propagation failures is the alert logs at all sites (local and if relevant all remote sites). When a job queue process attempts to execute a schedule and fails it will always write an error stack to the alert log. This error stack will also be written in a job queue process trace file, which will be written to the BACKGROUND_DUMP_DEST location for 10.2 and below, and in the DIAGNOSTIC_DEST location for 11g. The fact that errors are written to the alert log demonstrates that the schedule is executing. This means that the problem could be with the set up of the schedule. In this example the ORA-02068 demonstrates that the failure was at the remote site. Further investigation revealed that the remote database was not open, hence the ORA-03114 error. Starting the database resolved the problem. Thu Feb 14 10:40:05 2002 Propagation Schedule for (AQADM.MULTIPLEQ, SHANE816.WORLD) encountered following error:ORA-04052: error occurred when looking up Remote object [email protected]: error occurred at recursive SQL level 4ORA-02068: following severe error from SHANE816ORA-03114: not connected to ORACLEORA-06512: at "SYS.DBMS_AQADM_SYS", line 4770ORA-06512: at "SYS.DBMS_AQADM", line 548ORA-06512: at line 1 Other potential errors that may be written to the alert log can be found in the following notes:Document 827184.1 AQ Propagation with CLOB data types Fails with ORA-22990 (11.1)Document 846297.1 AQ Propagation Fails : ORA-00600[kope2upic2954] or Ora-00600[Kghsstream_copyn] (10.2, 11.1)Document 731292.1 ORA-25215 Reported on Local Propagation When Using Transformation with ANYDATA queue tables (10.2, 11.1, 11.2)Document 365093.1 ORA-07445 [kwqppay2aqe()+7360] Reported on Propagation of a Transformed Message (10.1, 10.2)Document 219416.1 Advanced Queuing Propagation Fails with ORA-22922 (9.0)Document 1203544.1 AQ Propagation Aborted with ORA-600 [ociksin: invalid status] on SYS.DBMS_AQADM_SYS.AQ$_PROPAGATION_PROCEDURE After Upgrade (11.1, 11.2)Document 1087324.1 ORA-01405 ORA-01422 reported by Advanced Queuing Propagation schedules after RAC reconfiguration (10.2)Document 1079577.1 Advanced Queuing Propagation Fails With "ORA-22370 incorrect usage of method" (9.2, 10.2, 11.1, 11.2)Document 332792.1 ORA-04061 error relating to SYS.DBMS_PRVTAQIP reported when setting up Statspack (8.1, 9.0, 9.2, 10.1)Document 353325.1 ORA-24056: Internal inconsistency for QUEUE <queue_name> and destination <dblink> (8.1, 9.0, 9.2, 10.1, 10.2, 11.1, 11.2)Document 787367.1 ORA-22275 reported on Propagating Messages with LOB component when propagating between 10.1 and 10.2 (10.1, 10.2)Document 566622.1 ORA-22275 when propagating >4K AQ$_JMS_TEXT_MESSAGEs from 9.2.0.8 to 10.2.0.1 (9.2, 10.1)Document 731539.1 ORA-29268: HTTP client error 401 Unauthorized Error when the AQ Servlet attempts to Propagate a message via HTTP (9.0, 9.2, 10.1, 10.2, 11.1)Document 253131.1 Concurrent Writes May Corrupt LOB Segment When Using Auto Segment Space Management (ORA-1555) (9.2)Document 118884.1 How to unschedule a propagation schedule stuck in pending stateDocument 222992.1 DBMS_AQADM.DISABLE_PROPAGATION_SCHEDULE Returns ORA-24082Document 282987.1 Propagated Messages marked UNDELIVERABLE after Drop and Recreate Of Remote QueueDocument 1204080.1 AQ Propagation Failing With ORA-25329 After Upgraded From 8i or 9i to 10g or 11g.Document 1233675.1 AQ Propagation stops after upgrade to 11.2.0.1 ORA-30757 4.3.1. Errors Related to Incorrect Network Configuration The most common propagation errors result from an incorrect network configuration. The list below contains common errors caused by tnsnames.ora file or database links being configured incorrectly: - ORA-12154: TNS:could not resolve service name- ORA-12505: TNS:listener does not currently know of SID given in connect descriptor- ORA-12514: TNS:listener could not resolve SERVICE_NAME - ORA-12541: TNS-12541 TNS:no listener 4.4. Check the Database Links Exist and are Functioning Correctly For schedules to remote databases confirm the database link exists via. SQL> col DBLINK for a45SQL> select QNAME, NVL(REGEXP_SUBSTR(DESTINATION, '[^@]+', 1, 2), DESTINATION) dblink2 from DBA_QUEUE_SCHEDULES3 where MESSAGE_DELIVERY_MODE = 'PERSISTENT';QNAME DBLINK------------------------------ ---------------------------------------------MY_QUEUE ORCL102B.WORLD Connect as the owner of the link and select across it to verify it works and connects to the database we expect. i.e. select * from ALL_QUEUES@ ORCL102B.WORLD; You need to ensure that the userid that scheduled the propagation (using DBMS_AQADM.SCHEDULE_PROPAGATION or DBMS_PROPAGATION_ADM.CREATE_PROPAGATION if using Streams) has access to the database link for the destination. 4.5. Has Propagation Been Correctly Scheduled? Check that the propagation schedule has been created and that a job queue process has been assigned. Look for the entry in DBA_QUEUE_SCHEDULES and SYS.AQ$_SCHEDULES for your schedule. For 10g and below, check that it has a JOBNO entry in SYS.AQ$_SCHEDULES, and that there is an entry in DBA_JOBS with that JOBNO. For 11g and above, check that the schedule has a JOB_NAME entry in SYS.AQ$_SCHEDULES, and that there is an entry in DBA_SCHEDULER_JOBS with that JOB_NAME. Check the destination is as intended and spelled correctly. SQL> select SCHEMA, QNAME, DESTINATION, SCHEDULE_DISABLED, PROCESS_NAME from DBA_QUEUE_SCHEDULES;SCHEMA QNAME DESTINATION S PROCESS------- ---------- ------------------ - -----------AQADM MULTIPLEQ AQ$_LOCAL N J000 AQ$_LOCAL in the destination column shows that the queue to which we are propagating to is in the same database as the source queue. If the propagation was to a remote (different) database, a database link will be in the DESTINATION column. The entry in the SCHEDULE_DISABLED column, N, means that the schedule is NOT disabled. If Y (yes) appears in this column, propagation is disabled and the schedule will not be executed. If not using Oracle Streams, propagation should resume once you have enabled the schedule by invoking DBMS_AQADM.ENABLE_PROPAGATION_SCHEDULE (for 10.2 Oracle Streams and above, the DBMS_PROPAGATION_ADM.START_PROPAGATION procedure should be used). The PROCESS_NAME is the name of the job queue process currently allocated to execute the schedule. This process is allocated dynamically at execution time. If the PROCESS_NAME column is null (empty) the schedule is not currently executing. You may need to execute this statement a number of times to verify if a process is being allocated. If a process is at some time allocated to the schedule, it is attempting to execute. SQL> select SCHEMA, QNAME, LAST_RUN_DATE, NEXT_RUN_DATE from DBA_QUEUE_SCHEDULES;SCHEMA QNAME LAST_RUN_DATE NEXT_RUN_DATE------ ----- ----------------------- ----------------------- AQADM MULTIPLEQ 13-FEB-2002 13:18:57 13-FEB-2002 13:20:30 In 11g, these dates are expressed in TIMESTAMP WITH TIME ZONE datatypes. If the NEXT_RUN_DATE and NEXT_RUN_TIME columns are null when this statement is executed, the scheduled propagation is currently in progress. If they never change it would suggest that the schedule itself is never executing. If the next scheduled execution is too far away, change the NEXT_TIME parameter of the schedule so that schedules are executed more frequently (assuming that the window is not set to be infinite). Parameters of a schedule can be changed using the DBMS_AQADM.ALTER_PROPAGATION_SCHEDULE call. In 10g and below, scheduling propagation posts a job in the DBA_JOBS view. The columns are more or less the same as DBA_QUEUE_SCHEDULES so you just need to recognize the job and verify that it exists. SQL> select JOB, WHAT from DBA_JOBS where WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%';JOB WHAT---- ----------------- 720 next_date := sys.dbms_aqadm.aq$_propaq(job); For 11g, scheduling propagation posts a job in DBA_SCHEDULER_JOBS instead: SQL> select JOB_NAME from DBA_SCHEDULER_JOBS where JOB_NAME like 'AQ_JOB$_%';JOB_NAME------------------------------AQ_JOB$_41 If no job exists, check DBA_QUEUE_SCHEDULES to make sure that the schedule has not been disabled. For 10g and below, the job number is dynamic for AQ propagation schedules. The procedure that is executed to expedite a propagation schedule runs, removes itself from DBA_JOBS, and then reposts a new job for the next scheduled propagation. The job number should therefore always increment unless the schedule has been set up to run indefinitely. 4.6. Is the Schedule Executing but Failing to Complete? Run the following query: SQL> select FAILURES, LAST_ERROR_MSG from DBA_QUEUE_SCHEDULES;FAILURES LAST_ERROR_MSG------------ -----------------------1 ORA-25207: enqueue failed, queue AQADM.INQ is disabled from enqueueingORA-02063: preceding line from SHANE816 The failures column shows how many times we have attempted to execute the schedule and failed. Oracle will attempt to execute the schedule 16 times after which it will be removed from the DBA_JOBS or DBA_SCHEDULER_JOBS view and the schedule will become disabled. The column DBA_QUEUE_SCHEDULES.SCHEDULE_DISABLED will show 'Y'. For 11g and above, the DBA_SCHEDULER_JOBS.STATE column will show 'BROKEN' for the job corresponding to DBA_QUEUE_SCHEDULES.JOB_NAME. Prior to 10g the back off algorithm for failures was exponential, whereas from 10g onwards it is linear. The propagation will become disabled on the 17th attempt. Only the last execution failure will be reflected in the LAST_ERROR_MSG column. That is, if the schedule fails 5 times for 5 different reasons, only the last set of errors will be recorded in DBA_QUEUE_SCHEDULES. Any errors need to be resolved to allow propagation to continue. If propagation has also become disabled due to 17 failures, first resolve the reason for the error and then re-enable the schedule using the DBMS_AQADM.ENABLE_PROPAGATION_SCHEDULE procedure, or DBMS_PROPAGATION_ADM.START_PROPAGATION if using 10.2 or above Oracle Streams. As soon as the schedule executes successfully the error message entries will be deleted. Oracle does not keep a history of past failures. However, when using Oracle Streams, the errors will be retained in the DBA_PROPAGATION view even after the schedule resumes successfully. See the following note for instructions on how to clear out the errors from the DBA_PROPAGATION view:Document 808136.1 How to clear the old errors from DBA_PROPAGATION view?If a schedule is active and no errors are being reported then the source queue may not have any messages to be propagated. 4.7. Do the Propagation Notification Queue Table and Queue Exist? Check to see that the propagation notification queue table and queue exist and are enabled for enqueue and dequeue. Propagation makes use of the propagation notification queue for handling propagation run-time events, and the messages in this queue are stored in a SYS-owned queue table. This queue should never be stopped or dropped and the corresponding queue table never be dropped. 10g and belowThe propagation notification queue table is of the format SYS.AQ$_PROP_TABLE_n, where 'n' is the RAC instance number, i.e. '1' for a non-RAC environment. This queue and queue table are created implicitly when propagation is first scheduled. If propagation has been scheduled and these objects do not exist, try unscheduling and rescheduling propagation. If they still do not exist contact Oracle Support. SQL> select QUEUE_TABLE from DBA_QUEUE_TABLES2 where QUEUE_TABLE like '%PROP_TABLE%' and OWNER = 'SYS';QUEUE_TABLE------------------------------AQ$_PROP_TABLE_1SQL> select NAME, ENQUEUE_ENABLED, DEQUEUE_ENABLED2 from DBA_QUEUES where owner='SYS'3 and QUEUE_TABLE like '%PROP_TABLE%';NAME ENQUEUE DEQUEUE------------------------------ ------- -------AQ$_PROP_NOTIFY_1 YES YESAQ$_AQ$_PROP_TABLE_1_E NO NO If the AQ$_PROP_NOTIFY_1 queue is not enabled for enqueue or dequeue, it should be so enabled using DBMS_AQADM.START_QUEUE. However, the exception queue AQ$_AQ$_PROP_TABLE_1_E should not be enabled for enqueue or dequeue.11g and aboveThe propagation notification queue table is of the format SYS.AQ_PROP_TABLE, and is created when the database is created. If they do not exist, contact Oracle Support. SQL> select QUEUE_TABLE from DBA_QUEUE_TABLES2 where QUEUE_TABLE like '%PROP_TABLE%' and OWNER = 'SYS';QUEUE_TABLE------------------------------AQ_PROP_TABLESQL> select NAME, ENQUEUE_ENABLED, DEQUEUE_ENABLED2 from DBA_QUEUES where owner='SYS'3 and QUEUE_TABLE like '%PROP_TABLE%';NAME ENQUEUE DEQUEUE------------------------------ ------- -------AQ_PROP_NOTIFY YES YESAQ$_AQ_PROP_TABLE_E NO NO If the AQ_PROP_NOTIFY queue is not enabled for enqueue or dequeue, it should be so enabled using DBMS_AQADM.START_QUEUE. However, the exception queue AQ$_AQ$_PROP_TABLE_E should not be enabled for enqueue or dequeue. 4.8. Does the Remote Queue Exist and is it Enabled for Enqueueing? Check that the remote queue the propagation is transferring messages to exists and is enabled for enqueue: SQL> select DESTINATION from USER_QUEUE_SCHEDULES where QNAME = 'OUTQ';DESTINATION-----------------------------------------------------------------------------"AQADM"."INQ"@M2V102.ESSQL> select OWNER, NAME, ENQUEUE_ENABLED, DEQUEUE_ENABLED from [email protected];OWNER NAME ENQUEUE DEQUEUE-------- ------ ----------- -----------AQADM INQ YES YES 4.9. Do the Target and Source Database Charactersets Differ? If a message fails to propagate, check the database charactersets of the source and target databases. Investigate whether the same message can propagate between the databases with the same characterset or it is only a particular combination of charactersets which causes a problem. 4.10. Check the Queue Table Type Agreement Propagation is not possible between queue tables which have types that differ in some respect. One way to determine if this is the case is to run the DBMS_AQADM.VERIFY_QUEUE_TYPES procedure for the two queues that the propagation operates on. If the types do not agree, DBMS_AQADM.VERIFY_QUEUE_TYPES will return '0'.For AQ propagation between databases which have different NLS_LENGTH_SEMANTICS settings, propagation will not work, unless the queues are Oracle Streams ANYDATA queues.See the following notes for issues caused by lack of type agreement:Document 1079577.1 Advanced Queuing Propagation Fails With "ORA-22370: incorrect usage of method"Document 282987.1 Propagated Messages marked UNDELIVERABLE after Drop and Recreate Of Remote QueueDocument 353754.1 Streams Messaging Propagation Fails between Single and Multi-byte Charactersets when using Chararacter Length Semantics in the ADT 4.11. Enable Propagation Tracing 4.11.1. System Level This is set it in the init.ora/spfile as follows: event="24040 trace name context forever, level 10" and restart the instanceThis event cannot be set dynamically with an alter system command until version 10.2: SQL> alter system set events '24040 trace name context forever, level 10'; To unset the event: SQL> alter system set events '24040 trace name context off'; Debugging information will be logged to job queue trace file(s) (jnnn) as propagation takes place. You can check the trace file for errors, and for statements indicating that messages have been sent. For the most part the trace information is understandable. This trace should also be uploaded to Oracle Support if a service request is created. 4.11.2. Attaching to a Specific Process We can also attach to an existing job queue processes that is running a propagation schedule and trace it individually using the oradebug utility, as follows:10.2 and below connect / as sysdbaselect p.SPID, p.PROGRAM from v$PROCESS p, DBA_JOBS_RUNNING jr, V$SESSION s, DBA_JOBS j where s.SID=jr.SID and s.PADDR=p.ADDR and jr.JOB=j.JOB and j.WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%';-- For the process id (SPID) attach to it via oradebug and generate the following traceoradebug setospid <SPID>oradebug unlimitoradebug Event 10046 trace name context forever, level 12oradebug Event 24040 trace name context forever, level 10-- Trace the process for 5 minutesoradebug Event 10046 trace name context offoradebug Event 24040 trace name context off-- The following command returns the pathname/filename to the file being written tooradebug tracefile_name 11g connect / as sysdbacol PROGRAM for a30select p.SPID, p.PROGRAM, j.JOB_NAMEfrom v$PROCESS p, DBA_SCHEDULER_RUNNING_JOBS jr, V$SESSION s, DBA_SCHEDULER_JOBS j where s.SID=jr.SESSION_ID and s.PADDR=p.ADDR and jr.JOB_NAME=j.JOB_NAME and j.JOB_NAME like '%AQ_JOB$_%';-- For the process id (SPID) attach to it via oradebug and generate the following traceoradebug setospid <SPID>oradebug unlimitoradebug Event 10046 trace name context forever, level 12oradebug Event 24040 trace name context forever, level 10-- Trace the process for 5 minutesoradebug Event 10046 trace name context offoradebug Event 24040 trace name context off-- The following command returns the pathname/filename to the file being written tooradebug tracefile_name 4.11.3. Further Tracing The previous tracing steps only trace the job queue process executing the propagation on the source. At times it is useful to trace the propagation receiver process (the session which is enqueueing the messages into the target queue) on the target database which is associated with the job queue process on the source database.These following queries provide ways of identifying the processes involved in propagation so that you can attach to them via oradebug to generate trace information.In order to identify the propagation receiver process you need to execute the query as a user with privileges to access the v$ views in both the local and remote databases so the database link must connect as a user with those privileges in the remote database. The <DBLINK> in the queries should be replaced by the appropriate database link.The queries have two forms due to the differences between operating systems. The value returned by 'Rem Process' is the operating system identifier of the propagation receiver on the remote database. Once identified, this process can be attached to and traced on the remote database using the commands given in Section 4.11.2.10.2 and below - Windows select pl.SPID "JobQ Process", pl.PROGRAM, sr.PROCESS "Rem Process" from v$PROCESS pl, DBA_JOBS_RUNNING jr, V$SESSION s, DBA_JOBS j, V$SESSION@<DBLINK> sr where s.SID=jr.SID and s.PADDR=pl.ADDR and jr.JOB=j.JOB and j.WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%' and pl.SPID=substr(sr.PROCESS, instr(sr.PROCESS,':')+1); 10.2 and below - Unix select pl.SPID "JobQ Process", pl.PROGRAM, sr.PROCESS "Rem Process" from V$PROCESS pl, DBA_JOBS_RUNNING jr, V$SESSION s, DBA_JOBS j, V$SESSION@<DBLINK> sr where s.SID=jr.SID and s.PADDR=pl.ADDR and jr.JOB=j.JOB and j.WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%' and pl.SPID=sr.PROCESS; 11g - Windows select pl.SPID "JobQ Process", pl.PROGRAM, sr.PROCESS "Rem Process" from V$PROCESS pl, DBA_SCHEDULER_RUNNING_JOBS jr, V$SESSION s, DBA_SCHEDULER_JOBS j, V$SESSION@<DBLINK> sr where s.SID=jr.SESSION_ID and s.PADDR=pl.ADDR and jr.JOB_NAME=j.JOB_NAME and j.JOB_NAME like '%AQ_JOB$_%%' and pl.SPID=substr(sr.PROCESS, instr(sr.PROCESS,':')+1); 11g - Unix select pl.SPID "JobQ Process", pl.PROGRAM, sr.PROCESS "Rem Process" from V$PROCESS pl, DBA_SCHEDULER_RUNNING_JOBS jr, V$SESSION s, DBA_SCHEDULER_JOBS j, V$SESSION@<DBLINK> sr where s.SID=jr.SESSION_ID and s.PADDR=pl.ADDR and jr.JOB_NAME=j.JOB_NAME and j.JOB_NAME like '%AQ_JOB$_%%' and pl.SPID=sr.PROCESS;   5. Additional Troubleshooting Steps for AQ Propagation of User-Enqueued and Dequeued Messages 5.1. Check the Privileges of All Users Involved Ensure that the owner of the database link has the necessary privileges on the aq packages. SQL> select TABLE_NAME, PRIVILEGE from USER_TAB_PRIVS;TABLE_NAME PRIVILEGE------------------------------ ----------------------------------------DBMS_LOCK EXECUTEDBMS_AQ EXECUTEDBMS_AQADM EXECUTEDBMS_AQ_BQVIEW EXECUTEQT52814_BUFFER SELECT Note that when queue table is created, a view called QT<nnn>_BUFFER is created in the SYS schema, and the queue table owner is given SELECT privileges on it. The <nnn> corresponds to the object_id of the associated queue table. SQL> select * from USER_ROLE_PRIVS;USERNAME GRANTED_ROLE ADM DEF OS_------------------------------ ------------------------------ ---- ---- ---AQ_USER1 AQ_ADMINISTRATOR_ROLE NO YES NOAQ_USER1 CONNECT NO YES NOAQ_USER1 RESOURCE NO YES NO It is good practice to configure central AQ administrative user. All admin and processing jobs are created, executed and administered as this user. This configuration is not mandatory however, and the database link can be owned by any existing queue user. If this latter configuration is used, ensure that the connecting user has the necessary privileges on the AQ packages and objects involved. Privileges for an AQ Administrative user Execute on DBMS_AQADM Execute on DBMS_AQ Granted the AQ_ADMINISTRATOR_ROLE Privileges for an AQ user Execute on DBMS_AQ Execute on the message payload Enqueue privileges on the remote queue Dequeue privileges on the originating queue Privileges need to be confirmed on both sites when propagation is scheduled to remote destinations. Verify that the user ID used to login to the destination through the database link has been granted privileges to use AQ. 5.2. Verify Queue Payload Types AQ will not propagate messages from one queue to another if the payload types of the two queues are not verified to be equivalent. An AQ administrator can verify if the source and destination's payload types match by executing the DBMS_AQADM.VERIFY_QUEUE_TYPES procedure. The results of the type checking will be stored in the SYS.AQ$_MESSAGE_TYPES table. This table can be accessed using the object identifier OID of the source queue and the address database link of the destination queue, i.e. [schema.]queue_name[@destination]. Prior to Oracle 9i the payload (message type) had to be the same for all the queue tables involved in propagation. From Oracle9i onwards a transformation can be used so that payloads can be converted from one type to another. The following procedural call made on the source database can verify whether we can propagate between the source and the destination queue tables. connect aq_user1/[email protected] serverout onDECLARErc_value number;BEGINDBMS_AQADM.VERIFY_QUEUE_TYPES(src_queue_name => 'AQ_USER1.Q_1', dest_queue_name => 'AQ_USER2.Q_2',destination => 'dbl_aq_user2.es',rc => rc_value);dbms_output.put_line('rc_value code is '||rc_value);END;/ If propagation is possible then the return code value will be 1. If it is 0 then propagation is not possible and further investigation of the types and transformations used by and in conjunction with the queue tables is required. With regard to comparison of the types the following sql can be used to extract the DDL for a specific type with' %' changed appropriately on the source and target. This can then be compared for the source and target. SET LONG 20000 set pagesize 50 EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'STORAGE',false); SELECT DBMS_METADATA.GET_DDL('TYPE',t.type_name) from user_types t WHERE t.type_name like '%'; EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'DEFAULT'); 5.3. Check Message State and Destination The first step in this process is to identify the queue table associated with the problem source queue. Although you schedule propagation for a specific queue, most of the meta-data associated with that queue is stored in the underlying queue table. The following statement finds the queue table for a given queue (note that this is a multiple-consumer queue table). SQL> select QUEUE_TABLE from DBA_QUEUES where NAME = 'MULTIPLEQ';QUEUE_TABLE --------------------MULTIPLEQTABLE For a small amount of messages in a multiple-consumer queue table, the following query can be run: SQL> select MSG_STATE, CONSUMER_NAME, ADDRESS from AQ$MULTIPLEQTABLE where QUEUE = 'MULTIPLEQ';MSG_STATE CONSUMER_NAME ADDRESS-------------- ----------------------- -------------READY AQUSER2 [email protected] AQUSER1READY AQUSER3 AQADM.INQ In this example we see 2 messages ready to be propagated to remote queues and 1 that is not. If the address column is blank, the message is not scheduled for propagation and can only be dequeued from the queue upon which it was enqueued. The MSG_STATE column values are discussed in Document 102330.1 Advanced Queueing MSG_STATE Values and their Interpretation. If the address column has a value, the message has been enqueued for propagation to another queue. The first row in the example includes a database link (@M2V102.ES). This demonstrates that the message should be propagated to a queue at a remote database. The third row does not include a database link so will be propagated to a queue that resides on the same database as the source queue. The consumer name is the intended recipient at the target queue. Note that we are not querying the base queue table directly; rather, we are querying a view that is available on top of every queue table, AQ$<queue_table_name>.A more realistic query in an environment where the queue table contains thousands of messages is8.0.3-compatible multiple-consumer queue table and all compatibility single-consumer queue tables select count(*), MSG_STATE, QUEUE from AQ$<queue_table_name>  group by MSG_STATE, QUEUE; 8.1.3 and 10.0-compatible queue tables select count(*), MSG_STATE, QUEUE, CONSUMER_NAME from AQ$<queue_table_name>group by MSG_STATE, QUEUE, CONSUMER_NAME; For multiple-consumer queue tables, if you did not see the expected CONSUMER_NAME , check the syntax of the enqueue code and verify the recipients are declared correctly. If a recipients list is not used on enqueue, check the subscriber list in the AQ$_<queue_table_name>_S view (note that a single-consumer queue table does not have a subscriber view. This view records all members of the default subscription list which were added using the DBMS_AQADM.ADD_SUBSCRIBER procedure and also those enqueued using a recipient list. SQL> select QUEUE, NAME, ADDRESS from AQ$MULTIPLEQTABLE_S;QUEUE NAME ADDRESS---------- ----------- -------------MULTIPLEQ AQUSER2 [email protected] AQUSER1 In this example we have 2 subscribers registered with the queue. We have a local subscriber AQUSER1, and a remote subscriber AQUSER2, on the queue INQ, owned by AQADM, at M2V102.ES. Unless overridden with a recipient list during enqueue every message enqueued to this queue will be propagated to INQ at M2V102.ES.For 8.1 style and above multiple consumer queue tables, you can also check the following information at the target: select CONSUMER_NAME, DEQ_TXN_ID, DEQ_TIME, DEQ_USER_ID, PROPAGATED_MSGID from AQ$<queue_table_name> where QUEUE = '<QUEUE_NAME>'; For 8.0 style queues, if the queue table supports multiple consumers you can obtain the same information from the history column of the queue table: select h.CONSUMER, h.TRANSACTION_ID, h.DEQ_TIME, h.DEQ_USER, h.PROPAGATED_MSGIDfrom AQ$<queue_table_name> t, table(t.history) h where t.Q_NAME = '<QUEUE_NAME>'; A non-NULL TRANSACTION_ID indicates that the message was successfully propagated. Further, the DEQ_TIME indicates the time of propagation, the DEQ_USER indicates the userid used for propagation, and the PROPAGATED_MSGID indicates the message ID of the message that was enqueued at the destination. 6. Additional Troubleshooting Steps for Propagation in an Oracle Streams Environment 6.1. Is the Propagation Enabled? For a propagation job to propagate messages, the propagation must be enabled. For Streams, a special view called DBA_PROPAGATION exists to convey information about Streams propagations. If messages are not being propagated by a propagation as expected, then the propagation might not be enabled. To query for this: SELECT p.PROPAGATION_NAME, DECODE(s.SCHEDULE_DISABLED, 'Y', 'Disabled','N', 'Enabled') SCHEDULE_DISABLED, s.PROCESS_NAME, s.FAILURES, s.LAST_ERROR_MSGFROM DBA_QUEUE_SCHEDULES s, DBA_PROPAGATION pWHERE p.DESTINATION_DBLINK = NVL(REGEXP_SUBSTR(s.DESTINATION, '[^@]+', 1, 2), s.DESTINATION) AND s.SCHEMA = p.SOURCE_QUEUE_OWNER AND s.QNAME = p.SOURCE_QUEUE_NAME AND MESSAGE_DELIVERY_MODE = 'PERSISTENT' order by PROPAGATION_NAME; At times, the propagation job may become "broken" or fail to start after an error has been encountered or after a database restart. If an error is indicated by the above query, an attempt to disable the propagation and then re-enable it can be made. In the examples below, for the propagation named STRMADMIN_PROPAGATE where the queue name is STREAMS_QUEUE owned by STRMADMIN and the destination database link is ORCL2.WORLD, the commands would be:10.2 and above exec dbms_propagation_adm.stop_propagation('STRMADMIN_PROPAGATE'); exec dbms_propagation_adm.start_propagation('STRMADMIN_PROPAGATE'); If the above does not fix the problem, stop the propagation specifying the force parameter (2nd parameter on stop_propagation) as TRUE: exec dbms_propagation_adm.stop_propagation('STRMADMIN_PROPAGATE',true); exec dbms_propagation_adm.start_propagation('STRMADMIN_PROPAGATE'); The statistics for the propagation as well as any old error messages are cleared when the force parameter is set to TRUE. Therefore if the propagation schedule is stopped with FORCE set to TRUE, and upon restart there is still an error message in DBA_PROPAGATION, then the error message is current.9.2 or 10.1 exec dbms_aqadm.disable_propagation_schedule('STRMADMIN.STREAMS_QUEUE','ORCL2.WORLD'); exec dbms.aqadm.enable_propagation_schedule('STRMADMIN.STREAMS_QUEUE','ORCL2.WORLD'); If the above does not fix the problem, perform an unschedule of propagation and then schedule_propagation: exec dbms_aqadm.unschedule_propagation('STRMADMIN.STREAMS_QUEUE','ORCL2.WORLD'); exec dbms_aqadm.schedule_propagation('STRMADMIN.STREAMS_QUEUE','ORCL2.WORLD'); Typically if the error from the first query in Section 6.1 recurs after restarting the propagation as shown above, further troubleshooting of the error is needed. 6.2. Check Propagation Rule Sets and Transformations Inspect the configuration of the rules in the rule set that is associated with the propagation process to make sure that they evaluate to TRUE as expected. If not, then the object or schema will not be propagated. Remember that when a negative rule evaluates to TRUE, the specified object or schema will not be propagated. Finally inspect any rule-based transformations that are implemented with propagation to make sure they are changing the data in the intended way.The following query shows what rule sets are assigned to a propagation: select PROPAGATION_NAME, RULE_SET_OWNER||'.'||RULE_SET_NAME "Positive Rule Set",NEGATIVE_RULE_SET_OWNER||'.'||NEGATIVE_RULE_SET_NAME "Negative Rule Set"from DBA_PROPAGATION; The next two queries list the propagation rules and their conditions. The first is for the positive rule set, the second is for the negative rule set: set long 4000select rsr.RULE_SET_OWNER||'.'||rsr.RULE_SET_NAME RULE_SET ,rsr.RULE_OWNER||'.'||rsr.RULE_NAME RULE_NAME,r.RULE_CONDITION CONDITION fromDBA_RULE_SET_RULES rsr, DBA_RULES rwhere rsr.RULE_NAME = r.RULE_NAME and rsr.RULE_OWNER = r.RULE_OWNER and RULE_SET_NAME in(select RULE_SET_NAME from DBA_PROPAGATION) order by rsr.RULE_SET_OWNER, rsr.RULE_SET_NAME;   set long 4000select c.PROPAGATION_NAME, rsr.RULE_SET_OWNER||'.'||rsr.RULE_SET_NAME RULE_SET ,rsr.RULE_OWNER||'.'||rsr.RULE_NAME RULE_NAME,r.RULE_CONDITION CONDITION fromDBA_RULE_SET_RULES rsr, DBA_RULES r ,DBA_PROPAGATION cwhere rsr.RULE_NAME = r.RULE_NAME and rsr.RULE_OWNER = r.RULE_OWNER andrsr.RULE_SET_OWNER=c.NEGATIVE_RULE_SET_OWNER and rsr.RULE_SET_NAME=c.NEGATIVE_RULE_SET_NAMEand rsr.RULE_SET_NAME in(select NEGATIVE_RULE_SET_NAME from DBA_PROPAGATION) order by rsr.RULE_SET_OWNER, rsr.RULE_SET_NAME; 6.3. Determining the Total Number of Messages and Bytes Propagated As in Section 3.1, determining if messages are flowing can be instructive to see whether the propagation is entirely hung or just slow. If the propagation is not in flow control (see Section 6.5.2), but the statistics are incrementing slowly, there may be a performance issue. For Streams implementations two views are available that can assist with this that can show the number of messages sent by a propagation, as well as the number of acknowledgements being returned from the target site: the V$PROPAGATION_SENDER view at the Source site and the V$PROPAGATION_RECEIVER view at the destination site. It is helpful to query both to determine if messages are being delivered to the target. Look for the statistics to increase.Source: select QUEUE_SCHEMA, QUEUE_NAME, DBLINK,HIGH_WATER_MARK, ACKNOWLEDGEMENT, TOTAL_MSGS, TOTAL_BYTESfrom V$PROPAGATION_SENDER; Target: select SRC_QUEUE_SCHEMA, SRC_QUEUE_NAME, SRC_DBNAME, DST_QUEUE_SCHEMA, DST_QUEUE_NAME, HIGH_WATER_MARK, ACKNOWLEDGEMENT, TOTAL_MSGS from V$PROPAGATION_RECEIVER; 6.4. Check Buffered Subscribers The V$BUFFERED_SUBSCRIBERS view displays information about subscribers for all buffered queues in the instance. This view can be queried to make sure that the site that the propagation is propagating to is listed as a subscriber address for the site being propagated from: select QUEUE_SCHEMA, QUEUE_NAME, SUBSCRIBER_ADDRESS from V$BUFFERED_SUBSCRIBERS; The SUBSCRIBER_ADDRESS column will not be populated when the propagation is local (between queues on the same database). 6.5. Common Streams Propagation Errors 6.5.1. ORA-02082: A loopback database link must have a connection qualifier. This error can occur if you use the Streams Setup Wizard in Oracle Enterprise Manager without first configuring the GLOBAL_NAME for your database. 6.5.2. ORA-25307: Enqueue rate too high. Enable flow control DBA_QUEUE_SCHEDULES will display this informational message for propagation when the automatic flow control (10g feature of Streams) has been invoked.Similar to Streams capture processes, a Streams propagation process can also go into a state of 'flow control. This is an informative message that indicates flow control has been automatically enabled to reduce the rate at which messages are being enqueued into at target queue.This typically occurs when the target site is unable to keep up with the rate of messages flowing from the source site. Other than checking that the apply process is running normally on the target site, usually no action is required by the DBA. Propagation and the capture process will be resumed automatically when the target site is able to accept more messages.The following document contains more information:Document 302109.1 Streams Propagation Error: ORA-25307 Enqueue rate too high. Enable flow controlSee the following document for one potential cause of this situation:Document 1097115.1 Oracle Streams Apply Reader is in 'Paused' State 6.5.3. ORA-25315 unsupported configuration for propagation of buffered messages This error typically occurs when the target database is RAC and usually indicates that an attempt was made to propagate buffered messages with the database link pointing to an instance in the destination database which is not the owner instance of the destination queue. To resolve the problem, use queue-to-queue propagation for buffered messages. 6.5.4. ORA-600 [KWQBMCRCPTS101] after dropping / recreating propagation For cause/fixes refer to:Document 421237.1 ORA-600 [KWQBMCRCPTS101] reported by a Qmon slave process after dropping a Streams Propagation 6.5.5. Stopping or Dropping a Streams Propagation Hangs See the following note:Document 1159787.1 Troubleshooting Streams Propagation When It is Not Functioning and Attempts to Stop It Hang 6.6. Streams Propagation-Related Notes for Common Issues Document 437838.1 Streams Specific PatchesDocument 749181.1 How to Recover Streams After Dropping PropagationDocument 368912.1 Queue to Queue Propagation Schedule encountered ORA-12514 in a RAC environmentDocument 564649.1 ORA-02068/ORA-03114/ORA-03113 Errors From Streams Propagation Process - Remote Database is Available and Unschedule/Reschedule Does Not ResolveDocument 553017.1 Stream Propagation Process Errors Ora-4052 Ora-6554 From 11g To 10201Document 944846.1 Streams Propagation Fails Ora-7445 [kohrsmc]Document 745601.1 ORA-23603 'STREAMS enqueue aborted due to low SGA' Error from Streams Propagation, and V$STREAMS_CAPTURE.STATE Hanging on 'Enqueuing Message'Document 333068.1 ORA-23603: Streams Enqueue Aborted Eue To Low SGADocument 363496.1 Ora-25315 Propagating on RAC StreamsDocument 368237.1 Unable to Unschedule Propagation. Streams Queue is InvalidDocument 436332.1 dbms_propagation_adm.stop_propagation hangsDocument 727389.1 Propagation Fails With ORA-12528Document 730911.1 ORA-4063 Is Reported After Dropping Negative Prop.RulesetDocument 460471.1 Propagation Blocked by Qmon Process - Streams_queue_table / 'library cache lock' waitsDocument 1165583.1 ORA-600 [kwqpuspse0-ack] In Streams EnvironmentDocument 1059029.1 Combined Capture and Apply (CCA) : Capture aborts : ORA-1422 after schedule_propagationDocument 556309.1 Changing Propagation/ queue_to_queue : false -> true does does not work; no LCRs propagatedDocument 839568.1 Propagation failing with error: ORA-01536: space quota exceeded for tablespace ''Document 311021.1 Streams Propagation Process : Ora 12154 After Reboot with Transparent Application Failover TAF configuredDocument 359971.1 STREAMS propagation to Primary of physical Standby configuation errors with Ora-01033, Ora-02068Document 1101616.1 DBMS_PROPAGATION_ADM.DROP_PROPAGATION FAILS WITH ORA-1747 7. Performance Issues A propagation may seem to be slow if the queries from Sections 3.1 and 6.3 show that the message statistics are not changing quickly. In Oracle Streams, this more usually is due to a slow apply process at the target rather than a slow propagation. Propagation could be inferred to be slow if the message statistics are changing, and the state of a capture process according to V$STREAMS_CAPTURE.STATE is PAUSED FOR FLOW CONTROL, but an ORA-25307 'Enqueue rate too high. Enable flow control' warning is NOT observed in DBA_QUEUE_SCHEDULES per Section 6.5.2. If this is the case, see the following notes / white papers for suggestions to increase performance:Document 335516.1 Master Note for Streams Performance RecommendationsDocument 730036.1 Overview for Troubleshooting Streams Performance IssuesDocument 780733.1 Streams Propagation Tuning with Network ParametersWhite Paper: http://www.oracle.com/technetwork/database/features/availability/maa-wp-10gr2-streams-performance-130059.pdfWhite Paper: Oracle Streams Configuration Best Practices: Oracle Database 10g Release 10.2, http://www.oracle.com/technetwork/database/features/availability/maa-10gr2-streams-configuration-132039.pdf, See APPENDIX A: USING STREAMS CONFIGURATIONS OVER A NETWORKFor basic AQ propagation, the network tuning in the aforementioned Appendix A of the white paper 'Oracle Streams Configuration Best Practices: Oracle Database 10g Release 10.2' is applicable. References NOTE:102330.1 - Advanced Queueing MSG_STATE Values and their InterpretationNOTE:102771.1 - Advanced Queueing Propagation using PL/SQLNOTE:1059029.1 - Combined Capture and Apply (CCA) : Capture aborts : ORA-1422 after schedule_propagationNOTE:1079577.1 - Advanced Queuing Propagation Fails With "ORA-22370: incorrect usage of method"NOTE:1083608.1 - 11g Streams and Oracle SchedulerNOTE:1087324.1 - ORA-01405 ORA-01422 reported by Adavanced Queueing Propagation schedules after RAC reconfigurationNOTE:1097115.1 - Oracle Streams Apply Reader is in 'Paused' StateNOTE:1101616.1 - DBMS_PROPAGATION_ADM.DROP_PROPAGATION FAILS WITH ORA-1747NOTE:1159787.1 - Troubleshooting Streams Propagation When It is Not Functioning and Attempts to Stop It HangNOTE:1165583.1 - ORA-600 [kwqpuspse0-ack] In Streams EnvironmentNOTE:118884.1 - How to unschedule a propagation schedule stuck in pending stateNOTE:1203544.1 - AQ PROPAGATION ABORTED WITH ORA-600[OCIKSIN: INVALID STATUS] ON SYS.DBMS_AQADM_SYS.AQ$_PROPAGATION_PROCEDURE AFTER UPGRADENOTE:1204080.1 - AQ Propagation Failing With ORA-25329 After Upgraded From 8i or 9i to 10g or 11g.NOTE:219416.1 - Advanced Queuing Propagation fails with ORA-22922NOTE:222992.1 - DBMS_AQADM.DISABLE_PROPAGATION_SCHEDULE Returns ORA-24082NOTE:253131.1 - Concurrent Writes May Corrupt LOB Segment When Using Auto Segment Space Management (ORA-1555)NOTE:282987.1 - Propagated Messages marked UNDELIVERABLE after Drop and Recreate Of Remote QueueNOTE:298015.1 - Kwqjswproc:Excep After Loop: Assigning To SelfNOTE:302109.1 - Streams Propagation Error: ORA-25307 Enqueue rate too high. Enable flow controlNOTE:311021.1 - Streams Propagation Process : Ora 12154 After Reboot with Transparent Application Failover TAF configuredNOTE:332792.1 - ORA-04061 error relating to SYS.DBMS_PRVTAQIP reported when setting up StatspackNOTE:333068.1 - ORA-23603: Streams Enqueue Aborted Eue To Low SGANOTE:335516.1 - Master Note for Streams Performance RecommendationsNOTE:353325.1 - ORA-24056: Internal inconsistency for QUEUE and destination NOTE:353754.1 - Streams Messaging Propagation Fails between Single and Multi-byte Charactersets when using Chararacter Length Semantics in the ADT.NOTE:359971.1 - STREAMS propagation to Primary of physical Standby configuation errors with Ora-01033, Ora-02068NOTE:363496.1 - Ora-25315 Propagating on RAC StreamsNOTE:365093.1 - ORA-07445 [kwqppay2aqe()+7360] reported on Propagation of a Transformed MessageNOTE:368237.1 - Unable to Unschedule Propagation. Streams Queue is InvalidNOTE:368912.1 - Queue to Queue Propagation Schedule encountered ORA-12514 in a RAC environmentNOTE:421237.1 - ORA-600 [KWQBMCRCPTS101] reported by a Qmon slave process after dropping a Streams PropagationNOTE:436332.1 - dbms_propagation_adm.stop_propagation hangsNOTE:437838.1 - Streams Specific PatchesNOTE:460471.1 - Propagation Blocked by Qmon Process - Streams_queue_table / 'library cache lock' waitsNOTE:463820.1 - Streams Combined Capture and Apply in 11gNOTE:553017.1 - Stream Propagation Process Errors Ora-4052 Ora-6554 From 11g To 10201NOTE:556309.1 - Changing Propagation/ queue_to_queue : false -> true does does not work; no LCRs propagatedNOTE:564649.1 - ORA-02068/ORA-03114/ORA-03113 Errors From Streams Propagation Process - Remote Database is Available and Unschedule/Reschedule Does Not ResolveNOTE:566622.1 - ORA-22275 when propagating >4K AQ$_JMS_TEXT_MESSAGEs from 9.2.0.8 to 10.2.0.1NOTE:727389.1 - Propagation Fails With ORA-12528NOTE:730036.1 - Overview for Troubleshooting Streams Performance IssuesNOTE:730911.1 - ORA-4063 Is Reported After Dropping Negative Prop.RulesetNOTE:731292.1 - ORA-25215 Reported On Local Propagation When Using Transformation with ANYDATA queue tablesNOTE:731539.1 - ORA-29268: HTTP client error 401 Unauthorized Error when the AQ Servlet attempts to Propagate a message via HTTPNOTE:745601.1 - ORA-23603 'STREAMS enqueue aborted due to low SGA' Error from Streams Propagation, and V$STREAMS_CAPTURE.STATE Hanging on 'Enqueuing Message'NOTE:749181.1 - How to Recover Streams After Dropping PropagationNOTE:780733.1 - Streams Propagation Tuning with Network ParametersNOTE:787367.1 - ORA-22275 reported on Propagating Messages with LOB component when propagating between 10.1 and 10.2NOTE:808136.1 - How to clear the old errors from DBA_PROPAGATION view ?NOTE:827184.1 - AQ Propagation with CLOB data types Fails with ORA-22990NOTE:827473.1 - How to alter propagation from queue_to_queue to queue_to_dblinkNOTE:839568.1 - Propagation failing with error: ORA-01536: space quota exceeded for tablespace ''NOTE:846297.1 - AQ Propagation Fails : ORA-00600[kope2upic2954] or Ora-00600[Kghsstream_copyn]NOTE:944846.1 - Streams Propagation Fails Ora-7445 [kohrsmc]

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  • Windows CE Chat Transcript (March 30, 2010)

    - by Bruce Eitman
    For those of you who missed the chat today, here is the raw transcript.   By raw, I mean that I copied and pasted the discussion without any edits. This is divided into two parts, the top part is the answers from the Microsoft Experts and the bottom part is the questions from the audience. Answers from Microsoft:   Karel Danihelka [MS] (Expert)[2010-3-30 12:2]: Hi everyone, my name is Karel Danihelka and I am developer in partner response team. Sing Wee [MS] (Expert)[2010-3-30 12:2]: Hi, I'm Sing Wee, part of the CoreOS/BSP Test Team. GLanger_MS (Expert)[2010-3-30 12:2]: Hi, I'm Glen Langer, program manager on the Core Team. Karel Danihelka [MS] (Expert)[2010-3-30 12:3]: Q: I need to implement hardware timers on my windows CE 6.0 device to trigger events at microsecond intervals. Where should i start? A: Until you are using CPU with GHz frequency your only chance is use interrupt handler and implement all funcionality there. But it will be really tricky and may reduce system performance. If period will be near to millisecond timeframe you can use normal thread wait for event pattern. Karel Danihelka [MS] (Expert)[2010-3-30 12:5]: Q: I want to partition my NAND Flash device. One partition to use for hive ragistry and the other for the apps and data. The only way to do it is programmatically or setting some registry values ? A: It need to be set in registry - generally you need mark this partition as boot partition. Karel Danihelka [MS] (Expert)[2010-3-30 12:7]: Q: My CPU is Intel celeron M processor 1Ghz. A: In this case you can try use normal approach - in interrupt handler return SYSINTR and start thread in device driver which will spin thread waiting on event attached to this SYSINTR. Karel Danihelka [MS] (Expert)[2010-3-30 12:7]: Q: If i need to implement it using interrupt handlers, What are all the files that I should look at? A: Good quesiton - I would recommend documentation and there was BSP development book to download for free. mikehall_ms (Moderator)[2010-3-30 12:8]: Q: Hi guys, what's the formal way to report bugs back to the core team / product team? The mechanism of calling the support phone number every time is really onerous and time-consuming. Is there another mechanism? A: Using product support is the formal way to report bugs/issues - Product support can then create an issue that can be tracked. Karel Danihelka [MS] (Expert)[2010-3-30 12:9]: Q: But the operation for creating the partitions ? A: This is tricky - if you will make it autopartition & autoformat it will be created by filesystem. But generally it depends on your boot loader. mikehall_ms (Moderator)[2010-3-30 12:10]: Q: Is Windows Phone 7 related to Windows CE? If so, can you tell me what version of Windows CE is the basis? Is it in fact the new version of Windows Mobile? A: At MIX 2010 Charlie Kindel presented a session that described some of the core technologies that make up Windows Phone 7 Series, including the underlying operating system (Windows CE) and the new ISV programming model based on Silverlight and .NET - check out the Mix Online Videos to get more information. davbo-msft (Moderator)[2010-3-30 12:10]: Q: Is Windows Phone 7 related to Windows CE? If so, can you tell me what version of Windows CE is the basis? Is it in fact the new version of Windows Mobile? A: This forum is to discussed released products in the industry. Windows Mobile & Windows CE are based on the same Windows CE Kernel/system. Windows CE is focused on deliverying the OS for embedded customers in the market where Windows Mobile is focused on deliverying compelling Windows Phone platform. davbo-msft (Moderator)[2010-3-30 12:11]: Q: Is Windows Phone 7 related to Windows CE? If so, can you tell me what version of Windows CE is the basis? Is it in fact the new version of Windows Mobile? A: http://en.wikipedia.org/wiki/Windows_CE Wikipedia gives a good breakdown of the version history. Travis Hobrla [MS] (Expert)[2010-3-30 12:13]: Q: I created a OS design with KITL and kernel debugger enabled. But I am unable to connect to the target for debugging. I am getting the following error when i try to connect with the device. PB Debugger Cannot initialize the Kernel Debugger. PB Debugger Debugger could not initialize connection. PB Debugger The Kernel Debugger is waiting to connect with target. PB Debugger The Kernel Debugger has been disconnected successfully. A: One possibility is that a rogue cesvchost.exe has co-opted the debugger. I am assuming this is CE 6.0? Can you try exiting visual studio and manually killing the cesvchost.exe process from the Task Manager? davbo-msft (Moderator)[2010-3-30 12:14]: Q: Hi guys, what's the formal way to report bugs back to the core team / product team? The mechanism of calling the support phone number every time is really onerous and time-consuming. Is there another mechanism? A: For info on contacting Microsoft support refer to the support page on the Embedded website: http://msdn.microsoft.com/en-us/windowsembedded/dd897633.aspx Sing Wee [MS] (Expert)[2010-3-30 12:16]: Q: Do u mean ISR/IST implementation? How can i register an interrupt? What kind of interrupt should i register? A: A good introduction to interrupts in WinCE 6.0 can be found here (aside from the documentation on MSDN): http://download.microsoft.com/download/9/c/f/9cffaa58-4000-48d6-a4b2-5fed9e4e6410/Chapter%206%20-%20Developing%20Device%20Drivers.pdf mikehall_ms (Moderator)[2010-3-30 12:16]: Q: What will be different in Windows Compact 7 from CE 6.0? A: Unfortunately we cannot discuss unreleased products on this chat - keep an eye on the Windows Embedded web site and blogs to keep up to date with product announcements. Travis Hobrla [MS] (Expert)[2010-3-30 12:16]: Q: I am using CE 6.0. There is no cesvchost process running in my system. A: What operating system are you using? Karel Danihelka [MS] (Expert)[2010-3-30 12:16]: Q: So...I have to modify file system code to create 2 partition at system startup ?!! I haven't understood.... A: You don't need to modify code, there are registry settings to achive this (look to documentation). But you may need to create partition table in boot loader. Unfortunatelly there isn't simple way how to do it. davbo-msft (Moderator)[2010-3-30 12:18]: Q: I would like to get a handle to a Silverlight screen section, is that possiable? A: Windows Embedded CE 6.0 R3 includes Sliverlight for Windows Embedded. Refer to New Features overview on the embedded web site. http://www.microsoft.com/windowsembedded/en-us/products/windowsce/default.mspx. Silverlight - The power of Silverlight brought to Windows Embedded CE to create rich applications and user interfaces is new part of Windows CE Embedded. mikehall_ms (Moderator)[2010-3-30 12:20]: Q: The link for developing device drivers is not working. can u please check that? A: http://msdn.microsoft.com/en-us/library/ms923714.aspx davbo-msft (Moderator)[2010-3-30 12:20]: Q: I would like to get a handle to a Silverlight screen section, is that possiable? A: Sorry misunderstood the question I thought you were asking if embedded CE could handle Silverlight. Please repost so that the question goes back into the active queue because once answered no way to put the status back to open. Travis Hobrla [MS] (Expert)[2010-3-30 12:21]: Q: sorry! Windows XP SP3 A: Can you try exiting VS2005 and confirming cesvchost.exe is not running, then renaming C:\Documents and Settings\USERNAME\Local Settings\Application Data\Microsoft\CoreCon\1.0 to 1.0_backup, then restarting VS2005? Sing Wee [MS] (Expert)[2010-3-30 12:24]: Q: Can I have the book's name please? A: I believe the downloadable version is related to the last link I sent. If you go to the following website, I believe you can download the whole thing: http://msdn.microsoft.com/en-us/windowsembedded/ce/cc294468.aspx davbo-msft (Moderator)[2010-3-30 12:24]: Q: If one has an image on a Silverlight page, it seems to be cached. How would one refresh that cache after changing the underlying image? A: change the URI of the image or use a writeable bitmap if they want to manually toggle the pixels Sing Wee [MS] (Expert)[2010-3-30 12:25]: A: Whoops, hit [ENTER] too early. On the right side, you'll see there an "Exam Preparation Kit" link that can be downloaded in several different languages. Sing Wee [MS] (Expert)[2010-3-30 12:25]: Q: Can I have the book's name please? A: Whoops, hit [ENTER] too early. On the right side, you'll see there an "Exam Preparation Kit" link that can be downloaded in several different languages. Karel Danihelka [MS] (Expert)[2010-3-30 12:26]: Q: I have a NAND Flash on my target device. On this flash I have the hive registry and an application.I have observed that when the NAND flash is fully, the system startup time is longer....is there a degradation of NAND use that influences the startup time ? Why ? A: Yes - on boot flash abstraction library (old one) read metadata from all sectors to rebuild physical - logical mapping table. davbo-msft (Moderator)[2010-3-30 12:27]: Q: I would like to get a handle to a Silverlight screen section, is that possiable? A: Need addition info on this question. Can you provide more details on what you are trying to do in Silverlight? davbo-msft (Moderator)[2010-3-30 12:27]: Q: If one has an image on a Silverlight page, it seems to be cached. How would one refresh that cache after changing the underlying image? A: Additonal Info: if you want to manually touch the pixels use WriteableBitmap if you want to use the underlying HWND then use IXRVisualHost::GetHWND() davbo-msft (Moderator)[2010-3-30 12:28]: Q: Writable bitmap, is there an example of the syntax? A: if you want to manually touch the pixels use WriteableBitmap if you want to use the underlying HWND then use IXRVisualHost::GetHWND() davbo-msft (Moderator)[2010-3-30 12:29]: Q: I would like to get a handle to a Silverlight screen section, is that possiable? A: Can I get more information about this question about what you are trying to accomplish in Silverlight? davbo-msft (Moderator)[2010-3-30 12:31]: Q: IXRVisualHost::GetHWND() exactly what I needed Thanks, A: Your welcome Sing Wee [MS] (Expert)[2010-3-30 12:31]: Q: ok. thanks for the book's link A: No problem. Travis Hobrla [MS] (Expert)[2010-3-30 12:32]: Q: Typically for SoC devices you name your hardware specific libraries in the form "SOCDIRNAME_LIBNAME". In our platform "OMAP35XX_TPS659XX_TI_V1" if you do this we cause the catalog parser to die... For example if we have a library "Musbfn_OMAP35XX_TPS659XX_TI_V1.dll" entering this in the catalogs pbcxml file in a <module> section causes the XML parser to fail with : Error 3 The 'urn:Microsoft.PlatformBuilder/Catalog:Module' element is        invalid - The value '012345678901234567890123456789.dll' is invalid         according to its datatype         'urn:Microsoft.PlatformBuilder/Catalog:CatalogFileName' - The actual         length is greater than the MaxLength value. A: There are a couple workarounds I can think of. I believe the Module element is only used when doing SYSGEN parsing to make sure dependent SYSGENs are present when the item is selected, so I believe it is optional to the catalog. The other obvious workaround is to shorten the soc name. I realize neither of these solutions is ideal. This is not something we anticipated when we tested CE6.0, sorry. Travis Hobrla [MS] (Expert)[2010-3-30 12:33]: Q: I am getting this error only when I select the KdStub as the debugger in Target device connectivity. A: Right, but KdStub is the debugger that you should use. Have you tried the steps I suggested? Travis Hobrla [MS] (Expert)[2010-3-30 12:36]: Q: If I select Active KTIL, My OS doesn't boots. It says "loading NK.EXE at 0x<xxxxx> location" after that nothing comes in the debug log. A: Can you look at the serial debug output and see what is happening there? Often it can give you a clue to the KITL driver malfunctioning. Travis Hobrla [MS] (Expert)[2010-3-30 12:38]: Q: I have tried that and I am getting the same error. A: I am assuming you have a device created in Target -> Connectivity Options in Platform Builder. What are the Kernel download / Kernel transport for your device? Travis Hobrla [MS] (Expert)[2010-3-30 12:40]: Q: KITL: *** Device Name CEPC56059 *** WARN: KITL will run in polling mode VBridge:: built on [Jul 10 2009] time [10:20:14] VBridgeInit()...TX = [16384] bytes -- Rx = [16384] bytes Tx buffer [0xA1B84860] to [0xA1B88860]. Rx buffer [0xA1B88880] to [0xA1B8C880]. VBridge:: NK add MAC: [0-60-65-2-DA-FB] Connecting to Desktop KITL: Connected host IP: 1 Port: 1086 .. this is the output of the serial debug A: This looks reasonable and does not give clues as to why boot would halt at that point. If you capture a network trace or turn on KITL debug zones via dpCurSettings in kitl.dll, do you see KITL active after this? Travis Hobrla [MS] (Expert)[2010-3-30 12:41]: Q: Both is happening via Ethernet. A: Only thing I have left to suggest is a Platform Builder installation Repair, then. Karel Danihelka [MS] (Expert)[2010-3-30 12:42]: Q: Hi, I saw that the ATADISK is quite generic and des not have any optimizations. Do you have any advice to consider while tryin to improve the performance of it? A: If I remember correctly sample code has support for some specific hardware controllers (little obsolete now). This should be good start point (if you will not decide take existing driver as sample and write you own). Travis Hobrla [MS] (Expert)[2010-3-30 12:44]: Q: I didn't do that. I have to try. A: I think that's the next valid step. You need to figure out whether KITL is hanging or the device - use instrumented serial debug messages and network trace to determine this. Sing Wee [MS] (Expert)[2010-3-30 12:46]: Q: KITL: *** Device Name CEPC56059 *** WARN: KITL will run in polling mode VBridge:: built on [Jul 10 2009] time [10:20:14] VBridgeInit()...TX = [16384] bytes -- Rx = [16384] bytes Tx buffer [0xA1B84860] to [0xA1B88860]. Rx buffer [0xA1B88880] to [0xA1B8C880]. VBridge:: NK add MAC: [0-60-65-2-DA-FB] Connecting to Desktop KITL: Connected host IP: 1 Port: 1086 .. this is the output of the serial debug A: Neo, have you by any chance tried looking into your firewall to see if it might be blocking traffic on any particular ports? Wireshark/netmon might be able to help you here if that's the issue. davbo-msft (Moderator)[2010-3-30 12:48]: Q: I lost spell check, how can i get it back A: Hello - can you give additional details about your question? Is this related to a Windows CE Embedded application? masatos_MSFT (Expert)[2010-3-30 12:51]: Q: When attempting to run the CETK cellcore tests the documentation states the pre-requisites include "stinger.ini", "ltk.ini" but windows CE doesn't provide these or document what they fully need to contain. Implicitly you also need "datatrans.xml" which isn't supplied. If you get around this error and steal these from Windows Mobile instead, when you try and run the CETK tests you get a data abort in radiometricsdll.dll. How should we invoke the cellcore parts of CETK? A: Hi Pev, what version of Windows CE and CETK are you using? I do not have the expertise to answer this question, but can find somebody who can. Travis Hobrla [MS] (Expert)[2010-3-30 12:52]: Q: I don't see a kitlcore.dll in my OS. is my debug image fails to load because of that? A: kitl.dll should be all that's needed, kitlcore.lib is linked into that. Travis Hobrla [MS] (Expert)[2010-3-30 12:55]: Q: I've got a platform (not developed by myself) where I2C bus support has to be provided through the OAL as the kernel needs to talk to devices such as the power management IC and gas gauge so a 'proper' I2C driver hanging off device manager isn't possible. This happens to be a polled driver, so obviously it hits the system hard when either under lots of traffic or an error condition occurs and the driver constantly polls. I originally thought that there was no straightforward way to make such code interrupt driven in the kernel (as it's a cludge) but I realised that that's exactly what ETHDBG drivers do. Is there any reason why I shouldn't have a go at implementing a similar mechanism for our kernel resident I2C driver? If not, are there any obvious pitfalls - I've not seen any other BSP's do this in the past... A: You can make a 'proper' driver that calls down into the OAL to do the actual I2C transactions. Alternatively you can build an interrupt-based version in the OAL where you handle everything in the ISR. There is nothing wrong with that so long as the rest of your drivers and app threads can handle longer times with interrupts off while you are servicing I2C interrupts. Sing Wee [MS] (Expert)[2010-3-30 12:55]: Q: I am having trouble with my mouse, I have the microsoft wireless mobile mouse 3000, when I push the scroll button I am suppose to have autoscroll instead it shows other web pages,Can you help me out tell me what to do!!! A: Sorry, this current chat is about Windows Embedded Compact. Hope you're able to find an answer to your question elsewhere. davbo-msft (Moderator)[2010-3-30 12:56]: Q: Is the Silverlight Animation "Spline" a BezierSpline? A: Spline - http://msdn.microsoft.com/en-us/library/ee501495.aspx<BR< a>>   masatos_MSFT (Expert)[2010-3-30 12:57]: Thanks for the info Pev. I will follow up with the CETK experts here and get back to you. davbo-msft (Moderator)[2010-3-30 12:59]: Q: Spline- bad link A: http://msdn.microsoft.com/en-us/library/ee501495.aspx davbo-msft (Moderator)[2010-3-30 13:0]: Q: Sorry, got to tirm the ">" A: No Worries http://msdn.microsoft.com/en-us/library/ee501495.aspx davbo-msft (Moderator)[2010-3-30 13:0]: Hello everyone, we are just about out of time. Thank you for joining us for our Windows Embedded CE 6.0 chat today! <http://www.Microsoft.com/Embedded>; A special thank you to the product group members for coming out. The transcript of today’s chat will be posted online as soon as possible, to <http://msdn.microsoft.com/en-us/chats>;. We’ll see you again for another chat next month. Please check <http://msdn.microsoft.com/en-us/chats>; for the list of upcoming chats. If you still have unanswered questions, let me suggest that you post them on one of our newsgroups on <http://msdn.microsoft.com/en-us/windowsembedded/ce/default.aspx> -Windows Embedded CE 6.0 R3 Now Available! <http://msdn.microsoft.com/windowsembedded/ce/dd630616.aspx>; davbo-msft (Moderator)[2010-3-30 13:1]: Q: hi everybody. I would like to know if there is something know about a bug in RTC API (VOIP), especially when using SIP. According the to the analysis with application verifyier there is a heap link in rtcdllmedia.dll. All of the unreleased chunks seem to have a size of 6560 bytes. A: I will follow up with the Networking Team for a response. davbo-msft (Moderator)[2010-3-30 13:1]: Q: Hi, we've problems with debugging of applications (= breakpoints in Platform Builder will be ignored) over KITL on Windows CE 5.0, if the PDB files are large (over 60MB). Are there any limitations to size of the PDB files? A: I will follow up with the tools team for a response and post with the transcript. Sing Wee [MS] (Expert)[2010-3-30 13:1]: Q: I am unable to use the target control in my development environment. any ideas? A: Make sure you have SYSGEN_SHELL=1 set in your build environment. davbo-msft (Moderator)[2010-3-30 13:3]: Q: what are the main differences between Object Store and RAM disk ? They are both in RAM...are there performance differences ? access differences ? A: I will follow up with the Core Team and get a response posted with the transcript to MSDN  The Questions   [2010-3-30 12:57]: Thanks for the info Pev. I will follow up with the CETK experts here and get back to you. [2010-3-30 12:59]:   [2010-3-30 13:0]:   [2010-3-30 13:0]: Hello everyone, we are just about out of time. Thank you for joining us for our Windows Embedded CE 6.0 chat today! <http://www.Microsoft.com/Embedded>; A special thank you to the product group members for coming out. The transcript of today’s chat will be posted online as soon as possible, to <http://msdn.microsoft.com/en-us/chats>;. We’ll see you again for another chat next month. Please check <http://msdn.microsoft.com/en-us/chats>; for the list of upcoming chats. If you still have unanswered questions, let me suggest that you post them on one of our newsgroups on <http://msdn.microsoft.com/en-us/windowsembedded/ce/default.aspx> -Windows Embedded CE 6.0 R3 Now Available! <http://msdn.microsoft.com/windowsembedded/ce/dd630616.aspx>; [2010-3-30 13:1]: [2010-3-30 13:1]: [2010-3-30 13:1]: [2010-3-30 13:3]: neo (Guest)[2010-3-30 11:37]: Hi all KellyG (Guest)[2010-3-30 11:37]: Hi KellyG (Guest)[2010-3-30 11:37]: I have a question unrelated to windows Ce embedded, can you please help me?? neo (Guest)[2010-3-30 11:38]: I need to implement hardware timers on my windows CE 6.0 device to trigger events at microsecond intervals! c neo (Guest)[2010-3-30 11:38]: yes. post it. May be i cud give a try KellyG (Guest)[2010-3-30 11:38]: My Product key listed on my tower is not the product key I need for microsoft office, but that is the only product key listed. neo (Guest)[2010-3-30 11:39]: I hope this is a chat for windows embedded. please post ur queries in office forums KellyG (Guest)[2010-3-30 11:39]: it is but i could not find a forum for office neo (Guest)[2010-3-30 11:40]: I think moderators will help u out. @ davbo-msft: can u help this guy? neo (Guest)[2010-3-30 11:41]: Q: I need to implement hardware timers on my windows CE 6.0 device to trigger events at microsecond intervals. Where should i start? davbo-msft (Moderator)[2010-3-30 11:50]: Our chat today covers the topic of Windows Embedded CE! 1. This chat will last for one hour. During this hour, our Experts will respond to as many questions as they can. Please understand that there may be some questions we cannot respond to due to lack of information or because the information is not yet public. 2. We encourage you to submit questions for our Experts. To do so, type your questions in the send box, select the “ask the Experts” box and click SEND. Questions sent directly to the Guest Chat room will not be answered by the Experts, but we encourage other community members to assist. 3. We ask that you stay on topic for the duration of the chat. This helps the Guests and Experts follow the conversation more easily. We invite you to ask off topic questions after this chat is over, but not during. 4. Please abide by the Chat Code of Conduct. Chat code of conduct: <http://msdn.microsoft.com/chats/chatroom.aspx?ctl=hlp#Conduct>; Pev (Guest)[2010-3-30 11:54]: Evening! davbo-msft (Moderator)[2010-3-30 11:54]: Hello everyone this is Dave Boyce - I worked in the Multimedia area for Windows CE. neo (Guest)[2010-3-30 11:55]: hello dave neo (Guest)[2010-3-30 11:55]: The chat code of conduct link is not working! Pev (Guest)[2010-3-30 11:56]: Best be polite just in case then ;-) neo (Guest)[2010-3-30 11:56]: davbo-msft (Moderator)[2010-3-30 11:57]: I'll check out the issue w/ the link paolopat (Guest)[2010-3-30 12:0]: Hello davbo-msft (Moderator)[2010-3-30 12:0]: We are pleased to welcome our Experts for today’s chat. I will have them introduce themselves now. Chat will begin in a couple of minutes. <http://www.Microsoft.com/Embedded>; paolopat (Guest)[2010-3-30 12:3]: Hello Experts ! neo (Guest)[2010-3-30 12:3]: Welcome all! paolopat (Guest)[2010-3-30 12:3]: Q: I want to partition my NAND Flash device. One partition to use for hive ragistry and the other for the apps and data. The only way to do it is programmatically or setting some registry values ? neo (Guest)[2010-3-30 12:3]: Q: I need to implement hardware timers on my windows CE 6.0 device to trigger events at microsecond intervals. Where should i start? neo (Guest)[2010-3-30 12:5]: Q: My CPU is Intel celeron M processor 1Ghz. Pev (Guest)[2010-3-30 12:5]: neo: if your silicon has multiple general purpose timers, pick one that's not in use for the system timer / profiler and set it up to trigger irqs for your purpose. You can't guarantee hard realtime type responses though... GarySwalling (Guest)[2010-3-30 12:5]: Q: Is Windows Phone 7 related to Windows CE? If so, can you tell me what version of Windows CE is the basis? Is it in fact the new version of Windows Mobile? Pev (Guest)[2010-3-30 12:6]: Q: Hi guys, what's the formal way to report bugs back to the core team / product team? The mechanism of calling the support phone number every time is really onerous and time-consuming. Is there another mechanism? paolopat (Guest)[2010-3-30 12:6]: Q: But the operation for creating the partitions ? neo (Guest)[2010-3-30 12:6]: Q: If i need to implement it using interrupt handlers, What are all the files that I should look at? GPM (Guest)[2010-3-30 12:6]: Q: I would like to get a handle to a Silverlight screen section, is that possiable? Jhony (Guest)[2010-3-30 12:7]: Q: I created a OS design with KITL and kernel debugger enabled. But I am unable to connect to the target for debugging. I am getting the following error when i try to connect with the device. PB Debugger Cannot initialize the Kernel Debugger. PB Debugger Debugger could not initialize connection. PB Debugger The Kernel Debugger is waiting to connect with target. PB Debugger The Kernel Debugger has been disconnected successfully. Charles (Guest)[2010-3-30 12:7]: What will be different in Windows Compact 7 from CE 6.0? neo (Guest)[2010-3-30 12:8]: Can I have the book's name please? kiefs_dev (Guest)[2010-3-30 12:8]: Q: hi everybody. I would like to know if there is something know about a bug in RTC API (VOIP), especially when using SIP. According the to the analysis with application verifyier there is a heap link in rtcdllmedia.dll. All of the unreleased chunks seem to have a size of 6560 bytes. paolopat (Guest)[2010-3-30 12:10]: Q: So...I have to modify file system code to create 2 partition at system startup ?!! I haven't understood.... neo (Guest)[2010-3-30 12:10]: Q: Do u mean ISR/IST implementation? How can i register an interrupt? What kind of interrupt should i register? neo (Guest)[2010-3-30 12:11]: Q: Can I have the book's name please? Charles (Guest)[2010-3-30 12:11]: Q: What will be different in Windows Compact 7 from CE 6.0? PaulT (Guest)[2010-3-30 12:11]: neo: I'd say that you really need the docs for YOUR BSP, not generic documents for BSPs in general. Each BSP may be architected differently. If you're using the CEPC BSP, then the documentation that comes with Platform Builder is a reasonable place to look. GPM (Guest)[2010-3-30 12:11]: Q: If one has an image on a Silverlight page, it seems to be cached. How would one refresh that cache after changing the underlying image? Elektrobit (Guest)[2010-3-30 12:12]: Q: Hi, we've problems with debugging of applications (= breakpoints in Platform Builder will be ignored) over KITL on Windows CE 5.0, if the PDB files are large (over 60MB). Are there any limitations to size of the PDB files? Jhony (Guest)[2010-3-30 12:15]: Q: I am using CE 6.0. There is no cesvchost process running in my system. alexquisi (Guest)[2010-3-30 12:15]: Q: Hi, I saw that the ATADISK is quite generic and des not have any optimizations. Do you have any advice to consider while tryin to improve the performance of it? Jhony (Guest)[2010-3-30 12:17]: Windows XP service pack 1 Jhony (Guest)[2010-3-30 12:17]: Q: sorry! Windows XP SP3 neo (Guest)[2010-3-30 12:19]: Q: The link for developing device drivers is not working. can u please check that? paolopat (Guest)[2010-3-30 12:20]: Q: I have a NAND Flash on my target device. On this flash I have the hive registry and an application.I have observed that when the NAND flash is fully, the system startup time is longer....is there a degradation of NAND use that influences the startup time ? Why ? Pev (Guest)[2010-3-30 12:20]: Q: When attempting to run the CETK cellcore tests the documentation states the pre-requisites include "stinger.ini", "ltk.ini" but windows CE doesn't provide these or document what they fully need to contain. Implicitly you also need "datatrans.xml" which isn't supplied. If you get around this error and steal these from Windows Mobile instead, when you try and run the CETK tests you get a data abort in radiometricsdll.dll. How should we invoke the cellcore parts of CETK? Pev (Guest)[2010-3-30 12:21]: Hi all, Pev (Guest)[2010-3-30 12:21]: oops Pev (Guest)[2010-3-30 12:21]: :-D Pev (Guest)[2010-3-30 12:24]: Typically for SoC devices you name your hardware specific libraries in the form "SOCDIRNAME_LIBNAME". In our platform "OMAP35XX_TPS659XX_TI_V1" if you do this we cause the catalog parser to die... For example if we have a library "Musbfn_OMAP35XX_TPS659XX_TI_V1.dll" entering this in the catalogs pbcxml file in a <module> section causes the XML parser to fail with : Pev (Guest)[2010-3-30 12:25]: Q: Error 3 The 'urn:Microsoft.PlatformBuilder/Catalog:Module' element is        invalid - The value '012345678901234567890123456789.dll' is invalid         according to its datatype         'urn:Microsoft.PlatformBuilder/Catalog:CatalogFileName' - The actual         length is greater than the MaxLength value. GPM (Guest)[2010-3-30 12:25]: Q: Writable bitmap, is there an example of the syntax? Pev (Guest)[2010-3-30 12:25]: Q: Typically for SoC devices you name your hardware specific libraries in the form "SOCDIRNAME_LIBNAME". In our platform "OMAP35XX_TPS659XX_TI_V1" if you do this we cause the catalog parser to die... For example if we have a library "Musbfn_OMAP35XX_TPS659XX_TI_V1.dll" entering this in the catalogs pbcxml file in a <module> section causes the XML parser to fail with : Error 3 The 'urn:Microsoft.PlatformBuilder/Catalog:Module' element is        invalid - The value '012345678901234567890123456789.dll' is invalid         according to its datatype         'urn:Microsoft.PlatformBuilder/Catalog:CatalogFileName' - The actual         length is greater than the MaxLength value. Pev (Guest)[2010-3-30 12:25]: sorry, messed up submission there! GPM (Guest)[2010-3-30 12:26]: Q: I would like to get a handle to a Silverlight screen section, is that possiable? GPM (Guest)[2010-3-30 12:28]: Q: IXRVisualHost::GetHWND() exactly what I needed Thanks, PaulT (Guest)[2010-3-30 12:29]: GPM: You don't have to keep submitting the questions. The chat experts have an application that they're using to follow the chat and all Ask the Experts questions are logged. Jhony (Guest)[2010-3-30 12:29]: Q: I am getting this error only when I select the KdStub as the debugger in Target device connectivity. neo (Guest)[2010-3-30 12:30]: Q: ok. thanks for the book's link Pev (Guest)[2010-3-30 12:31]: Hm, did those two I submitted get picked up by anyone? neo (Guest)[2010-3-30 12:33]: Q: If I select Active KTIL, My OS doesn't boots. It says "loading NK.EXE at 0x<xxxxx> location" after that nothing comes in the debug log. PaulT (Guest)[2010-3-30 12:34]: Pev: PaulT (Guest)[2010-3-30 12:35]: Pev: I'm sure they did. The guys who are actually on the chat may not be experts in that part of things. That's usually the explanation when you don't get an answer in 10 minutes or so. Pev (Guest)[2010-3-30 12:36]: Ah, fair enough Susie (Guest)[2010-3-30 12:36]: My Outlook Express incoming mail is corrput. No ONE has been able to fix the problem, Dell or Norton. I have dial up I'm in a rural area Jhony (Guest)[2010-3-30 12:37]: Q: I have tried that and I am getting the same error. Pev (Guest)[2010-3-30 12:37]: Susie : Use Thunderbird instead :-D PaulT (Guest)[2010-3-30 12:37]: Susie: Sorry, but this chat is not about Windows, but Embedded (like what runs on a phone). Your best chance is to find a local expert or talk to your ISP. paolopat (Guest)[2010-3-30 12:37]: Q: what are the main differences between Object Store and RAM disk ? They are both in RAM...are there performance differences ? access differences ? Susie (Guest)[2010-3-30 12:38]: My computer knowlege is very limited, what is Thunderbird? Pev (Guest)[2010-3-30 12:38]: A different email client :-D neo (Guest)[2010-3-30 12:39]: Q: KITL: *** Device Name CEPC56059 *** WARN: KITL will run in polling mode VBridge:: built on [Jul 10 2009] time [10:20:14] VBridgeInit()...TX = [16384] bytes -- Rx = [16384] bytes Tx buffer [0xA1B84860] to [0xA1B88860]. Rx buffer [0xA1B88880] to [0xA1B8C880]. VBridge:: NK add MAC: [0-60-65-2-DA-FB] Connecting to Desktop KITL: Connected host IP: 1 Port: 1086 .. this is the output of the serial debug Susie (Guest)[2010-3-30 12:39]: Do I need to uninstall Outlook Express youngboyzie (Guest)[2010-3-30 12:39]: I need to start battery calibration for my new battery for my dell inspiron 1525 laptop and should be able to reach the BIOS screen by hitting f2 but this isnt working... help? Pev (Guest)[2010-3-30 12:39]: Nah, you can run it instead - you'll still need help from your ISP to configure it I expect Jhony (Guest)[2010-3-30 12:39]: Q: Both is happening via Ethernet. PaulT (Guest)[2010-3-30 12:40]: youngboyzie: You're off-topic. This is not a general chat for Windows and certainly not for Dell. You'll have to ask Dell how to get to setup; it's their machine. bill (Guest)[2010-3-30 12:41]: I lost spell check, how can i get et back neo (Guest)[2010-3-30 12:42]: Q: I didn't do that. I have to try. Jhony (Guest)[2010-3-30 12:43]: Q: Ok. I will do it then. bill (Guest)[2010-3-30 12:43]: Q: I lost spell check, how can i get it back PaulT (Guest)[2010-3-30 12:44]: bill: This isn't a general Windows chat. There are some Web forums that you might try. GarySwalling (Guest)[2010-3-30 12:45]: Q: Thanks, I found the Phone 7 presentation at http://live.visitmix.com/MIX10/Sessions/CL13 GPM (Guest)[2010-3-30 12:45]: Q: Is the Silverlight Animation "Spline" a BezierSpline? neo (Guest)[2010-3-30 12:46]: Q: ok. I'll do it. thanks Pev (Guest)[2010-3-30 12:46]: Whowever was asking about KITL connection : I've had this loads in the past. I think I started debugging last time by using wireshark to see what was happening on the network then setting up the OAL_ETHER and OAL_FUNC and OAL_VERBOSE as well as OAL_KITL flags to see what was actually happening in the driver.... Pev (Guest)[2010-3-30 12:47]: I'd generally make sure that you're testing though a 10baseT hub (instead of anything faster) and forcing Active KITL in polled mode too... neo (Guest)[2010-3-30 12:48]: Q: I disabled the firewall in my PC. Pev (Guest)[2010-3-30 12:50]: Q: I've got a platform (not developed by myself) where I2C bus support has to be provided through the OAL as the kernel needs to talk to devices such as the power management IC and gas gauge so a 'proper' I2C driver hanging off device manager isn't possible. This happens to be a polled driver, so obviously it hits the system hard when either under lots of traffic or an error condition occurs and the driver constantly polls. I originally thought that there was no straightforward way to make such code interrupt driven in the kernel (as it's a cludge) but I realised that that's exactly what ETHDBG drivers do. Is there any reason why I shouldn't have a go at implementing a similar mechanism for our kernel resident I2C driver? If not, are there any obvious pitfalls - I've not seen any other BSP's do this in the past... neo (Guest)[2010-3-30 12:51]: Q: I don't see a kitlcore.dll in my OS. is my debug image fails to load because of that? Pev (Guest)[2010-3-30 12:52]: Q: Hi masatos, I'm using Windows Embedded CE 6.0 with R3 and patched to feb 2010's QFE's (with it's associated CETK version) this is a machine with only CE 6.0 on (no conflicts with earlier CE or WM...) neo (Guest)[2010-3-30 12:54]: ok. Got it neo (Guest)[2010-3-30 12:54]: Q: ok. Got it Roundman (Guest)[2010-3-30 12:55]: Q: I am having trouble with my mouse, I have the microsoft wireless mobile mouse 3000, when I push the scroll button I am suppose to have autoscroll instead it shows other web pages,Can you help me out tell me what to do!!! Pev (Guest)[2010-3-30 12:55]: Hey neo, debugging kitl issues is really frustrating but dont lose heart :-) neo (Guest)[2010-3-30 12:55]: @ pev : u fixed the problem of KITL after that? neo (Guest)[2010-3-30 12:56]: I am getting the same error again and again. I even cleaned my environment and tried in a fresh PC. But didn't succeed yet Pev (Guest)[2010-3-30 12:56]: Well, eventually - my experiences probably won't help you as different platforms have different reasons for doing that neo (Guest)[2010-3-30 12:56]: I think so PaulT (Guest)[2010-3-30 12:58]: neo: Have you searched the old messages in microsoft.public.windowsce.platbuilder? It seems to me that there was a packet size situation where it was possible to have problems with KITL connections based on a setting on the PC. Google Groups, groups.google.com, Advanced Groups Search will allow you to search a single newsgroup or a set of newsgroups easily. GPM (Guest)[2010-3-30 12:58]: Q: Spline- bad link PaulT (Guest)[2010-3-30 12:58]: GPM: without the > at the end does it work? It seems to for me... neo (Guest)[2010-3-30 12:58]: But some times if i try to connect to the device again. The Image information is seen in the serial debug. what does that mean?Download BIN file information: ----------------------------------------------------- [0]: Base Address=0x220000 Length=0x18DAADC Received a broadcast message !CheckUDP: Not UDP (proto = 0x00000001) after this i am getting the old errors. PB debugger cannot initialize ... GPM (Guest)[2010-3-30 12:59]: Q: Sorry, got to tirm the ">" neo (Guest)[2010-3-30 12:59]: ok paul. I ll look into that. davbo-msft (Moderator)[2010-3-30 13:0]: Hello everyone, we are just about out of time. Thank you for joining us for our Windows Embedded CE 6.0 chat today! <http://www.Microsoft.com/Embedded>; A special thank you to the product group members for coming out. The transcript of today’s chat will be posted online as soon as possible, to <http://msdn.microsoft.com/en-us/chats>;. We’ll see you again for another chat next month. Please check <http://msdn.microsoft.com/en-us/chats>; for the list of upcoming chats. If you still have unanswered questions, let me suggest that you post them on one of our newsgroups on <http://msdn.microsoft.com/en-us/windowsembedded/ce/default.aspx> -Windows Embedded CE 6.0 R3 Now Available! <http://msdn.microsoft.com/windowsembedded/ce/dd630616.aspx>; neo (Guest)[2010-3-30 13:1]: Q: I am unable to use the target control in my development environment. any ideas? Pev (Guest)[2010-3-30 13:1]: Sure, if KITL isn't connected target control won't work as it runs over kitl... neo (Guest)[2010-3-30 13:1]: ok .thanks pev neo (Guest)[2010-3-30 13:2]: yes. sysgen_shell is set to 1 neo (Guest)[2010-3-30 13:2]: Q: yes. sysgen_shell is set to 1 Marcelovk (Guest)[2010-3-30 13:2]: Q: Is there any way to extract the default command lines of the tests in CETK? I want to have it running unconnected from the desktop.   Copyright © 2010 – Bruce Eitman All Rights Reserved

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