Search Results

Search found 7891 results on 316 pages for 'multi layer perceptron'.

Page 275/316 | < Previous Page | 271 272 273 274 275 276 277 278 279 280 281 282  | Next Page >

  • Hibernate Session flush behaviour [ and Spring @Transactional ]

    - by EugeneP
    I use Spring and Hibernate in a web-app, SessionFactory is injected into a DAO bean, and then this DAO is used in a Servlet through webservicecontext. DAO methods are transactional, inside one of the methods I use ... getCurrentSession().save(myObject); One servlet calls this method with an object passed. The update seems to not be flushed at once, it takes about 5 seconds to see the changes in the database. The servlet's method in which that DAO's update method is called, takes a fraction of second to complete. After the @Transactional method of DAO is completed, flushing may NOT happen ? It does not seem to be a rule [ I already see it ]. Then the question is this: what to do to force the session to flush after every DAO method? It may not be a good thing to do, but talking about a Service layer, some methods must end with immediate flush, and Hibernate Session behavior is not predictable. So what to do to guarantee that my @Transactional method persists all the changes after the last line of that method code? getCurrentSession().flush() is the only solution? p.s. I read somewhere that @Transactional IS ASSOCIATED with a DB Transaction. Method returns, transaction must be committed. I do not see this happens.

    Read the article

  • How do I make JavaScript to set these element values?

    - by dmanexe
    I have two fields that need to multiply each other and fill a 3rd form's value. Here's the HTML: <input type="text" name="estimate[concrete][price]" value="" onBlur="calc_concreteprice(document.forms.mainform);" /> per SF <strong>times</strong> <input type="text" name="estimate[concrete][sqft]" value="" onBlur="calc_concreteprice(document.forms.mainform);" /> SF = <input type="text" name="estimate[concrete][quick_total]" value="" /> Here's my JavaScript: function calc_concreteprice(mainform) { var oprice; var ototal; oprice = ((mainform.estimate[concrete][sqft].value) * (mainform.estimate[concrete][price].value)); ototal = (oprice); mainform.estimate[concrete][quick_total].value = ototal; } I want the first two forms to be multiplied together and output to the third. I think my problem may be within how I am referencing the input field names, with brackets (I'm taking results from this form as an array so I'm already used to working with the results as a multi-dimensional array). Thanks for the help!

    Read the article

  • Exception when click DataGridview tab c#, .Net 4.0

    - by Nguyen Nam
    My winform app have two tab and multi thread, one is main tab and other is log tab. I only use log tab to show logs in a datagridview control. Exception is random occurred when click to log tab (Not click to row or colunm), i have try but can not find anyway to fix it. This is the error log: Message : Object reference not set to an instance of an object. Source : System.Windows.Forms TargetSite : System.Windows.Forms.DataGridViewElementStates GetRowState(Int32) StackTrace : at System.Windows.Forms.DataGridViewRowCollection.GetRowState(Int32 rowIndex) at System.Windows.Forms.DataGridView.ComputeHeightOfFittingTrailingScrollingRows(Int32 totalVisibleFrozenHeight) at System.Windows.Forms.DataGridView.GetOutOfBoundCorrectedHitTestInfo(HitTestInfo& hti, Int32& mouseX, Int32& mouseY, Int32& xOffset, Int32& yOffset) at System.Windows.Forms.DataGridView.OnMouseMove(MouseEventArgs e) at System.Windows.Forms.Control.WmMouseMove(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.DataGridView.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) Message : Object reference not set to an instance of an object. Source : System.Windows.Forms TargetSite : Void ClearInternal(Boolean) StackTrace : at System.Windows.Forms.DataGridViewRowCollection.ClearInternal(Boolean recreateNewRow) at System.Windows.Forms.DataGridView.OnClearingColumns() at System.Windows.Forms.DataGridViewColumnCollection.Clear() at System.Windows.Forms.DataGridView.Dispose(Boolean disposing) at System.ComponentModel.Component.Dispose() at System.Windows.Forms.Control.Dispose(Boolean disposing) at System.ComponentModel.Component.Dispose() at System.Windows.Forms.Control.Dispose(Boolean disposing) at System.Windows.Forms.TabControl.Dispose(Boolean disposing) at System.ComponentModel.Component.Dispose() at System.Windows.Forms.Control.Dispose(Boolean disposing) at System.Windows.Forms.Form.Dispose(Boolean disposing) Update status code: private void updateMessage(int index, string message) { try { this.dgForums.Rows[index].Cells["ColStatus"].Value = message; System.Windows.Forms.Application.DoEvents(); } catch { } }

    Read the article

  • TableTools only exporting single header row

    - by Rakeesh
    I am using the DataTable jquery plugin from: http://datatables.net/ I have a DataTable that has multi-row table header with colspan. Something like: <thead> <tr> <th>Level 1</th> <th colspan='2'>Level 1 - Item 1</th> <th colspan='2'>Level 1 - Item 2</th> </tr> <tr> <th>Level 2</th> <th>Level 2 - Item 1a</th> <th>Level 2 - Item 1b</th> <th>Level 2 - Item 2a</th> <th>Level 2 - Item 2b</th> </tr> </thead> However when I use the TableTools plugin to export then except for the "Print" option all the rest (Excel, CSV, Pdf etc) only has the "Level 2" header row and not the Level 1. Any suggestions on how to get it to export also Level 1?

    Read the article

  • Seperating two graphs based on connectivity and coordinates

    - by martin
    I would like to separate existing data of vertices and edges into two or more graphs that are not connected. I would like to give the following as example: Imagine two hexagons on top of each other but are lying in different Z. Hexagon 1 has the following vertices A(0,0,1), B(1,0,2), C(2,1,2), D(1,2,1), E(0,2,1), F(-1,2,1). The connectivity is as following: A-B, B-C, C-D, D-E, E-F, F-A. This part of Graph 1 as all the vertices are connected in this layer. Hexagon2 has the following vertices A1(0,0,6), B1(1,0,7), C1(2,1,7), D1(1,2,8), E1(0,2,7), F1(-1,2,6). The connectivity is as following: A1-B1, B1-C1, C1-D1, D1-E1, E1-F1, F1-A1. This is part of Graph 2 My data is in the following form: list of Vertices and list of Edges that i can form graphs with. I would like to eliminate graph 2 and give only vertices and connectivity of graph 1 to polygon determination part of my algorithm. My real data contains around 1000 connected polygons as graph 1 and around 100 (much larger in area) polygons as graph 2. I would like to eliminate graph 2. I am programming this in python. Thanks in advance.

    Read the article

  • Servlet File Upload Memory Consumption

    - by Scott
    Hi, I'm using a servlet to do a multi fileupload (using apache commons fileupload to help). A portion of my code is posted below. My problem is that if I upload several files at once, the memory consumption of the app server jumps rather drastically. This is probably OK if it were only until the file upload is finished, but the app server seems to hang on to the memory and never return it to the OS. I'm worried that when I put this into production I'll end up getting an out of memory exception on the server. Any ideas on why this is happening? I'm thinking the server may have started a session and will give the memory back after it expires, but I'm not 100% positive. if(ServletFileUpload.isMultipartContent(request)) { ServletFileUpload upload = new ServletFileUpload(); FileItemIterator iter = upload.getItemIterator(request); while(iter.hasNext()) { FileItemStream license = iter.next(); if(license.getFieldName().equals("upload_button") || license.getName().equals("")) continue; //DataInputStream stream = new DataInputStream(license.openStream()); InputStream stream = license.openStream(); ArrayList<Integer> byteArray = new ArrayList<Integer>(); int tempByte; do { tempByte = stream.read(); byteArray.add(tempByte); }while(tempByte != -1); stream.close(); byteArray.remove(byteArray.size()-1); byte[] bytes = new byte[byteArray.size()]; int i = 0; for(Integer tByte : byteArray) { bytes[i++] = tByte.byteValue(); } Thanks in advanced!!

    Read the article

  • Tiny MCE (jquery plugin version) not showing toolbar in IE (works fine in other browsers)

    - by I am Wonder
    I had an implementation working well but for some reason IE decided it was tired of playing nice. I have an advanced implementation of TinyMCE (the jquery plugin version - see http://tinymce.moxiecode.com/examples/example_23.php for details). It still works great in all browsers but IE. In IE it shows the drop-down options for Format, Font family, and Font size, but only as text.. not as a drop down normally looks. All other buttons on the toolbar are missing. (I've tried IE8 and IE8 Compatibility Mode) I get a javascript error: Syntax error Line 36 Char 1. Unfortunately the javascript is being loaded dynamically so this doesn't help me. Here is my implementation code for the TinyMCE editor: $(function () { $('#InputStuffHere').tinymce({ // General options theme: "advanced", plugins: "safari,pagebreak,style,layer,table,save,advhr,advimage,advlink,inlinepopups,preview,media,searchreplace,contextmenu,paste,fullscreen,noneditable,visualchars,nonbreaking,template", // Theme options theme_advanced_buttons1: "bold,italic,underline,strikethrough,|,justifyleft,justifycenter,justifyright,justifyfull,formatselect,fontselect,fontsizeselect,|,hr,removeformat", theme_advanced_buttons2: "cut,copy,paste,pastetext,pasteword,|,search,replace,|,bullist,numlist,|,outdent,indent,blockquote,|,undo,redo,|,link,unlink,image,|,forecolor,backcolor,|,spellchecker", theme_advanced_buttons3 : "", theme_advanced_toolbar_location: "top", theme_advanced_toolbar_align: "left", theme_advanced_statusbar_location: "bottom", theme_advanced_resizing: true, // Drop lists for link/image/media/template dialogs template_external_list_url: "lists/template_list.js", external_link_list_url: "lists/link_list.js", external_image_list_url: "lists/image_list.js", media_external_list_url: "lists/media_list.js", //initialization callback init_instance_callback: "TinyMCEReady", add_form_submit_trigger : false }); }); So... anyone seen anything like this or have any ideas for me? Thank you so much everyone!

    Read the article

  • Textarea (asp:Textbox TextMode="Multiline") overlapping buttons

    - by Gogster
    Hi all, I'm having this problem with form buttons overlapping an asp:Texbox with TextMode set to multi-line: Here is the code: <asp:Panel ID="pnlGiftStep" Visible="false" runat="server"> <img src="/images/shopping-cart/form-separator.png" alt="separator" /> <div class="form-title">GIFT OPTIONS</div> <div class="row"> <asp:TextBox ID="txtGiftName" Height="31" Width="323" BorderStyle="None" Font-Names="Arial" Font-Size="116.7%" runat="server"></asp:TextBox> <cc1:TextBoxWatermarkExtender ID="wmeGiftName" TargetControlID="txtGiftName" WatermarkText="Gift Name" WatermarkCssClass="watermark" runat="server"></cc1:TextBoxWatermarkExtender> </div> <br class="clear" /> <div class="row"> <asp:TextBox ID="txtGiftMessage" Rows="5" Width="323" BorderStyle="None" Font-Names="Arial" TextMode="MultiLine" Font-Size="116.7%" runat="server"></asp:TextBox> <cc1:TextBoxWatermarkExtender ID="wmeGiftMessage" TargetControlID="txtGiftMessage" WatermarkText="Gift Message" WatermarkCssClass="watermark" runat="server"></cc1:TextBoxWatermarkExtender> </div> <br class="clear" /> <div class="button-row"> <asp:ImageButton ID="imbShippingDetails" ImageUrl="/images/shopping-cart/ship-details-btn.png" OnClick="ReturnToShipping" ValidationGroup="shipping" runat="server" /> <asp:ImageButton ID="imbPayDetails" ImageUrl="/images/shopping-cart/pay-details-btn.png" ValidationGroup="pay" runat="server" /> </div> <br class="clear" /> </asp:Panel> Here is the CSS: .row { float:left; height:40px; } .button-row { float:left; width:323px; text-align:right; } Any ideas how I can stop this? Thanks.

    Read the article

  • For each result in MySQL query, push to array (complicated)

    - by Dylan Taylor
    Okay, here's what I'm trying to do. I am running a MySQL query for the most recent posts. For each of the returned rows, I need to push the ID of the row to an array, then within that ID in the array, I need to add more data from the rows. A multi-dimensional array. Here's my code thus far. $query = "SELECT * FROM posts ORDER BY id DESC LIMIT 10"; $result = mysql_query($query); while($row = mysql_fetch_array($result)){ $id = $row["id"]; $post_title = $row["title"]; $post_text = $row["text"]; $post_tags = $row["tags"]; $post_category = $row["category"]; $post_date = $row["date"]; } As you can see I haven't done anything with arrays yet. Here's an ideal structure I'm looking for, just incase you're confused. The master array I guess you could call it. We'll just call this array $posts. Within this array, I have one array for each row returned in my MySQL query. Within those arrays there is the $post_title, $post_text, etc. How do I do this? I'm so confused.. an example would be really appreciated. -Dylan

    Read the article

  • Stopping Filter Display in Dynamic Data Entity Web App

    - by bert
    I'm currently experimenting with the Dynamic Data Entity Web App Project type in VS2008 SP1 and after reading many tutorials which offer helpful advice for problems I so far have no need of a solution to I have fallen at the first hurdle. In the DB I have made my entity model from I decided to start small with a table called "Companies" just to see if I could tweak the display into a satisfactory shape for this small table. The Companies table has a column called "contactid" which leads to a record filled with various contact information in a "contacts" table. The default created Entity Data Model has guessed that One companies could have many contact records. So it tries to be helpful and add a "Contact" filter onto the page that allows you to see all the Companies that share a particular set of contact info indexed by the "Contact Name" field. Unfortunately the contact table is a multi-purpose one that also stores contact info for customers and there are about 1000 times more customers than there are companies. So the Dropdown makes the page load time increase exponentially and produces no benefit. So I'd like to just stop the filter from appearing. Only problem is I don't have a clue how to switch it off. Google is so far proving recalcitrant on the matter so I wondered if anyone in here knew how to get rid of a useless filter.

    Read the article

  • perl multithreading issue for autoincrement

    - by user3446683
    I'm writing a multi threaded perl script and storing the output in a csv file. I'm trying to insert a field called sl.no. in the csv file for each row entered but as I'm using threads, the sl. no. overlaps in most. Below is an idea of my code snippet. for ( my $count = 1 ; $count <= 10 ; $count++ ) { my $t = threads->new( \&sub1, $count ); push( @threads, $t ); } foreach (@threads) { my $num = $_->join; } sub sub1 { my $num = shift; my $start = '...'; #distributing data based on an internal logic my $end = '...'; #distributing data based on an internal logic my $next; for ( my $x = $start ; $x <= $end ; $x++ ) { my $count = $x + 1; #part of code from which I get @data which has name and age my $j = 0; if ( $x != 0 ) { $count = $next; } foreach (@data) { #j is required here for some extra code flock( OUTPUT, LOCK_EX ); print OUTPUT $count . "," . $name . "," . $age . "\n"; flock( OUTPUT, LOCK_UN ); $j++; $count++; } $next = $count; } return $num; } I need the count to be incremented which is the serial number for the rows that would be inserted in the csv file. Any help would be appreciated.

    Read the article

  • How can I keep the the logic to translate a ViewModel's values to a Where clause to apply to a linq query out of My Controller?

    - by Mr. Manager
    This same problem keeps cropping up. I have a viewModel that doesn't have any persistent backing. It is just a ViewModel to generate a search input form. I want to build a large where clause from the values the user entered. If the Action Accepts as a parameter SearchViewModel How do I do this without passing my viewModel to my service layer? Service shouldn't know about ViewModels right? Oh and if I serialize it, then it would be a big string and the key/values would be strongly typed. SearchViewModel this is just a snippet. [Display(Name="Address")] public string AddressKeywords { get; set; } /// <summary> /// Gets or sets the census. /// </summary> public string Census { get; set; } /// <summary> /// Gets or sets the lot block sub. /// </summary> public string LotBlockSub { get; set; } /// <summary> /// Gets or sets the owner keywords. /// </summary> [Display(Name="Owner")] public string OwnerKeywords { get; set; } In my controller action I was thinking of something like this. but I would think all this logic doesn't belong in my Controller. ActionResult GetSearchResults(SearchViewModel model){ var query = service.GetAllParcels(); if(model.Census != null){ query = query.Where(x=>x.Census == model.Census); } if (model.OwnerKeywords != null){ query = query.Where(x=>x.Owners == model.OwnerKeywords); } return View(query.ToList()); }

    Read the article

  • Print UITableView that has content off screen?

    - by Daniel
    Hi I have an iOS app that has the ability to print a UITableView. However, only th part of the tableview that is shown is printed. Is there a way to print the whole tableview, even if it has not been drawn yet? Here is the code I am using to print: UIGraphicsBeginImageContext(self.mainTableView.contentSize); [self.mainTableView.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); UIPrintInteractionController *printer = [UIPrintInteractionController sharedPrintController]; printer.printingItem = viewImage; UIPrintInfo *info = [UIPrintInfo printInfo]; printer.printInfo = info; UIPrintInteractionCompletionHandler completionHandler = ^(UIPrintInteractionController *pic, BOOL completed, NSError *error) { if (!completed && error) NSLog(@"FAILED! due to error in domain %@ with error code %u: %@", error.domain, error.code, [error localizedDescription]); }; UIButton * printButton = (UIButton *)sender; if(UIUserInterfaceIdiomPad == [[UIDevice currentDevice] userInterfaceIdiom]){ [printer presentFromRect:printButton.frame inView:self.view animated:YES completionHandler:completionHandler]; } else { [printer presentAnimated:YES completionHandler:completionHandler]; }

    Read the article

  • How to write curiously recurring templates with more than 2 layers of inheritance?

    - by Kyle
    All the material I've read on Curiously Recurring Template Pattern seems to one layer of inheritance, ie Base and Derived : Base<Derived>. What if I want to take it one step further? #include <iostream> using std::cout; template<typename LowestDerivedClass> class A { public: LowestDerivedClass& get() { return *static_cast<LowestDerivedClass*>(this); } void print() { cout << "A\n"; } }; template<typename LowestDerivedClass> class B : public A<LowestDerivedClass> { public: void print() { cout << "B\n"; } }; class C : public B<C> { public: void print() { cout << "C\n"; } }; int main() { C c; c.get().print(); // B b; // Intentionally bad syntax, // b.get().print(); // to demonstrate what I'm trying to accomplish return 0; } How can I rewrite this code to compile without errors (and output "C\nB\n")?

    Read the article

  • Where should I put validation code?

    - by D Lawson
    I'm creating interfaces and abstract classes that represent a messaging framework for short text-based messages like SMS, email, twitter, xml, etc.. and I was wondering where I should put the message validation code. The thing is that I am only writing the superclasses and interfaces, so I'm not putting the actual implementation in, I'll just put the hooks in that allow others to validate the content of the messages. The way I see it, I could do it several ways: in the abstract superclass "Message", have an abstract method 'isValid'. A variation on this would be to have isValid be called when the Message constructor is called, throwing a MalformedMessageException if the message is formatted incorrectly. in the transport layer, immediately before sending, validate the message. I would have a send(Message) method that calls an isValid(Message) method immediately before it sends. have a singleton message validator with a static method isValid(Message) that is called at some point. I'm sure there are other options that I'm missing. Currently, I'm leaning towards the first one, but it doesn't feel right to me to have validation code in what should be a domain object.

    Read the article

  • Error in django using Apache & mod_wsgi

    - by Ignacio
    Hey, I've been doing some changes to my django develpment env, as some of you suggested. So far I've managed to configure and run it successfully with postgres. Now I'm trying to run the app using apache2 and mod_wsgi, but I ran into this little problem after I followed the guidelines from the django docs. When I access localhost/myapp/tasks this error raises: Request Method: GET Request URL: http://localhost/myapp/tasks/ Exception Type: TemplateSyntaxError Exception Value: Caught an exception while rendering: argument 1 must be a string or unicode object Original Traceback (most recent call last): File "/usr/local/lib/python2.6/dist-packages/django/template/debug.py", line 71, in render_node result = node.render(context) File "/usr/local/lib/python2.6/dist-packages/django/template/defaulttags.py", line 126, in render len_values = len(values) File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 81, in __len__ self._result_cache = list(self.iterator()) File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 238, in iterator for row in self.query.results_iter(): File "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/query.py", line 287, in results_iter for rows in self.execute_sql(MULTI): File "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/query.py", line 2369, in execute_sql cursor.execute(sql, params) File "/usr/local/lib/python2.6/dist-packages/django/db/backends/util.py", line 19, in execute return self.cursor.execute(sql, params) TypeError: argument 1 must be a string or unicode object ... ... ... And then it highlights a {% for t in tasks %} template tag, like the source of the problem is there, but it worked fine on the built-in server. The view associated with that page is really simple, just fetch all Task objects. And the template just displays them on a table. Also, some pages get rendered ok. Don't want to fill this Question with code, so if you need some more info I'd be glad to provide it. Thanks

    Read the article

  • (HTML) PNG on top of another PNG - possible to eliminate full transparency?

    - by MHTri
    I'd like to put a logo png onto of another coloured png. They both have transparent backgrounds. When I try this the images blend together. Curiously, in Photoshop the logo retains its opaque-ness - I put colours on the layers underneath it, another image, etc etc, the logo is still opaque. I'd like to do it this way so I can rotate the background images. How do I fix this? [edit]I've cooked up an example image: http://i.imgur.com/XtoGn.png The left is what I want to happen, the right is what happens on all browsers (I know the background isn't transparent but bear with me - they're both transparent pngs, with the background having a gradient layer mask). I've put the images like this <div> <img id="backgroundImg" style="position: absolute; top: 0;" src="/Images/background.png" /> <img id="logoImg" src="/Images/logo.png" /> </div> I'm not entirely sure what blending mode I'm using in PS.

    Read the article

  • Why would dynamically changing the stroke type of a GestureOverlayView cause unusual behaviour?

    - by Rob Kent
    I recently introduced multi-stroke gestures into my application. This is a preference so I set the StrokeType dynamically in Activity.OnCreate. What I have discovered is that if you change the StrokeType so that it is different to the setting in the layout file, it changes the behaviour of the GestureOverlayView in the following way. The normal behaviour is that you draw a gesture and it stays on the screen after it is drawn. When you change the stroke type dynamically however, any gesture drawn on the screen disappears immediately after the OnGestureEnded event has fired. I reloaded the sample GesturesBuilder application and confirmed it has the same problem if you add the second line shown here: GestureOverlayView overlay = (GestureOverlayView) findViewById(R.id.gestures_overlay); overlay.setGestureStrokeType(GestureOverlayView.GESTURE_STROKE_TYPE_SINGLE); overlay.addOnGestureListener(new GesturesProcessor()); } The default in the layout is MULTIPLE but changing it to single changes the behaviour. If you keep the above line but set it to what it already is, the behaviour is not affected. Is this a bug in the Android gestures library and does anyone know a workaround? Note that this is on an HTC Magic so it could also be a handset issue.

    Read the article

  • What is the best way to get a reference to a spring bean in the backend layers?

    - by java_pill
    I have two spring config files and I'm specifying them in my web.xml as in below. web.xml snippet .. <context-param> <param-name>contextConfigLocation</param-name> <param-value>WEB-INF/classes/domain-context.xml WEB-INF/classes/client-ws.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> .. From my domain object I have to invoke a Web Service Client and in order to get a reference to the Web Service client I do this: ApplicationContext context = new ClassPathXmlApplicationContext("client-ws.xml"); //b'cos I don't want to use WebApplicationContextUtils ProductServiceClient client = (ProductServiceClient) context.getBean("productClient"); .. client.find(prodID); //calls a Web Service .. However, I have concerns that looking up the client-ws.xml file and getting a reference to the ProductServiceClient bean is not efficient. I thought of getting it using WebApplicationContextUtils. However, I don't want my domain objects to have a dependency on the ServletContext (a web/control layer object) because WebApplicationContextUtils depends on ServletContext. What is the best way to get a reference to a spring bean in the backend layers? Thanks!

    Read the article

  • Periodically iterating over a collection that's constantly changing

    - by rwmnau
    I have a collection of objects that's constantly changing, and I want to display some information about objects (my application is multi-threaded, and differently threads are constantly submitting requests to modify an object in the collection, so it's unpredictable), and I want to display some information about what's currently in the collection. If I lock the collection, I can iterate over it and get my information without any problems - however, this causes problems with the other threads, since they could have submitted multiple requests to modify the collection in the meantime, and will be stalled. I've thought of a couple ways around this, and I'm looking for any advice. Make a copy of the collection and iterate over it, allowing the original to continue updating in the background. The collection can get large, so this isn't ideal, but it's safe. Iterate over it using a For...Next loop, and catch an IndexOutOfBounds exception if an item is removed from the collection while we're iterating. This may occasionally cause duplicates to appear in my snapshot, so it's not ideal either. Any other ideas? I'm only concerned about a moment-in-time snapshot, so I'm not concerned about reflecting changes in my application - my main concern is that the collection be able to be updated with minimal latency, and that updates never be lost.

    Read the article

  • Optimize SQL connection?

    - by user1484035
    I am building a multi-page web project in HTML and Javascript that is constantly reading from AND writing to an SQL database. I can connect to the database and successfully run my project with this type of connection. var connection = new ActiveXObject("ADODB.Connection") ; var connectionstring="Data Source=<server>;Initial Catalog=<catalog>;User ID=<user>; Password=<password>;Provider=SQLOLEDB"; connection.Open(connectionstring); var rs = new ActiveXObject("ADODB.Recordset"); rs.Open("SELECT * FROM table", connection); rs.MoveFirst while(!rs.eof) { document.write(rs.fields(1)); rs.movenext; } rs.close; connection.close; Works great and runs fine. BUT, the first 5 lines (from var connection = to var rs =) causes the whole browser to freeze for a few seconds while it establishes the connection. I need to speed that up since I am constantly connecting to the database throughout my project. Is there a more effective way of connecting to a SQL database? or is my computer just bad and this should run faster?

    Read the article

  • How do you handle huge if-conditions?

    - by Teifion
    It's something that's bugged me in every language I've used, I have an if statement but the conditional part has so many checks that I have to split it over multiple lines, use a nested if statement or just accept that it's ugly and move on with my life. Are there any other methods that you've found that might be of use to me and anybody else that's hit the same problem? Example, all on one line: if (var1 = true && var2 = true && var2 = true && var3 = true && var4 = true && var5 = true && var6 = true){ Example, multi-line: if (var1 = true && var2 = true && var2 = true && var3 = true && var4 = true && var5 = true && var6 = true){ Example-nested: if (var1 = true && var2 = true && var2 = true && var3 = true){     if (var4 = true && var5 = true && var6 = true)     {

    Read the article

  • Parallelizing L2S Entity Retrieval

    - by MarkB
    Assuming a typical domain entity approach with SQL Server and a dbml/L2S DAL with a logic layer on top of that: In situations where lazy loading is not an option, I have settled on a convention where getting a list of entities does not also get each item's child entities (no loading), but getting a single entity does (eager loading). Since getting a single entity also gets children, it causes a cascading effect in which each child then gets its children too. This sounds bad, but as long as the model is not too deep, I usually don't see performance problems that outweigh the benefits of the ease of use. So if I want to get a list in which each of the items is fully hydrated with children, I combine the GetList and GetItem methods. So I'll get a list and then loop through it getting each item with the full cascade. Even this is generally acceptable in many of the projects I've worked on - but I have recently encountered situations with larger models and/or more data in which it needs to be more efficient. I've found that partitioning the loop and executing it on multiple threads yields excellent results. In my first experiment with a list of 50 items from one particular project, I did 5 threads of 10 items each and got a 3X improvement in time. Of course, the mileage will vary depending on the project but all else being equal this is clearly a big opportunity. However, before I go further, I was wondering what others have done that have already been through this. What are some good approaches to parallelizing this type of thing?

    Read the article

  • EGODatabase does not retain inserted record

    - by user135775
    Hi Guy! I'm using EGODatabase to process my data. When I tried to insert data into the database which I created with Base and attached to the project, the data that was inserted programmatically will not show up when I restart my app.However the data inserted manually using Base will show up just fine. Following is the code for inserting data into the database: NSString *path = [[NSBundle mainBundle] pathForResource:@"Database" ofType:@"db"]; db = [EGODatabase databaseWithPath:path]; if ([db open]) { NSLog(@"Database is opened successfully!"); } else { NSLog(@"Database is failed to open!"); } NSArray *params = [NSArray arrayWithObjects:[aFeed feedID], [aFeed title], nil]; [db executeUpdate:@"Insert INTO Feed (FeedID, Title) VALUES (?, ?)" parameters:params]; EGODatabaseResult *results = [db executeQuery:@"SELECT * FROM Feed"]; for ( EGODatabaseRow * row in results) { NSLog(@"ID: %@ Title: %@", [row stringForColumn:@"FeedID"], [row stringForColumn:@"Title"]); } I appreciate if anyone can share me a working sample code for EGODatabase. I'm using EGODatabase because I might have multi-threading code that write to the database. Thank in advance.

    Read the article

  • Choosing approach for an IM client-server app

    - by John
    Update: totally re-wrote this to be more succint. I'm looking at a new application, one part of which will be very similar to standard IM clients, i.e text chat, ability to send attachments, maybe some real-time interaction like a multi-user whiteboard. It will be client-server, i.e all traffic goes through my central server. That means if I want to support cross-communication with other IM systems, I am still free to pick any protocol for my own client<--server communication - my server can use XMPP or whatever to talk to other systems. Clients are expected to include desktop apps, but probably also browser-based as well either through Flex/Silverlight or HTML/AJAX. I see 3 options for my own client-server communication layer: XMPP. The benefits are clients already exist as do open-source servers. However it requires the most up-front research/learning and also appears like it might raise legal issues due to GPL. Custom sockets. A server app makes connections with the clients, allowing any text/binary data to be sent very fast. However this approach requires building said server from scratch, and also makes a JS client tricky Servlets (or similar web server). Using tried and tested Java web-stack, clients send HTTP requests similar to AJAX-based websites. The benefit is the server is easy to write using well-established technologies, and easy to talk to. But what restrictions would this bring? Is it appropriate technology for real-time communication? Advice and suggests are welcome, especially what pros and cons surround using a web-server approach as compared to a socket-based approach.

    Read the article

< Previous Page | 271 272 273 274 275 276 277 278 279 280 281 282  | Next Page >