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• Memory mapped files and "soft" page faults. Unavoidable?

  - by Robert Oschler

  I have two applications (processes) running under Windows XP that share data via a memory mapped file. Despite all my efforts to eliminate per iteration memory allocations, I still get about 10 soft page faults per data transfer. I've tried every flag there is in CreateFileMapping() and CreateFileView() and it still happens. I'm beginning to wonder if it's just the way memory mapped files work. If anyone there knows the O/S implementation details behind memory mapped files I would appreciate comments on the following theory: If two processes share a memory mapped file and one process writes to it while another reads it, then the O/S marks the pages written to as invalid. When the other process goes to read the memory areas that now belong to invalidated pages, this causes a soft page fault (by design) and the O/S knows to reload the invalidated page. Also, the number of soft page faults is therefore directly proportional to the size of the data write. My experiments seem to bear out the above theory. When I share data I write one contiguous block of data. In other words, the entire shared memory area is overwritten each time. If I make the block bigger the number of soft page faults goes up correspondingly. So, if my theory is true, there is nothing I can do to eliminate the soft page faults short of not using memory mapped files because that is how they work (using soft page faults to maintain page consistency). What is ironic is that I chose to use a memory mapped file instead of a TCP socket connection because I thought it would be more efficient. Note, if the soft page faults are harmless please note that. I've heard that at some point if the number is excessive, the system's performance can be marred. If soft page faults intrinsically are not significantly harmful then if anyone has any guidelines as to what number per second is "excessive" I'd like to hear that. Thanks.

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• Algorithms for finding a numerical record in a list of ordered numbers

  - by Ankur

  I have a list of incomplete ordered numbers. I want to find a particular number with as few steps as possible. Are there any improvements on this algorithm, I assume you can count the set size without difficulty - it will be stored and updated every time a new item is added. Your object is to get your cursor over the value x The first number (smallest) is s, and the last number (greatest) is g. Take the midpoint m1 of the set: calculate is x < m1, If yes then s <= x < m1 If no then m1 < x <= g If m1 = x then you're done. Keep repeating till you find x. Basically dividing the set into two parts with each iteration till you hit x. The purpose is to retrieve a numerical id from a very large table to then find the associated other records. I would imagine this is the most trivial kind of indexing available, are there improvements?

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• Building simple Reddit scraper

  - by Bazant Fundator

  Let's say that I would like to make a collection of images from reddit for my own amusement. I have ran the code on my development env and It haven't gone past the first page of posts (anything beyond requries the after string from the JSON. Additionally, When I turn on the validation, the whole loop breaks if the item doesn't pass it, not just the current iteration. I would be glad If you helped me understand mistakes I made. class Link include Mongoid::Document include Mongoid::Timestamps field :author, type: String field :url, type: String validates_uniqueness_of :url, # no duplicates validates :url, uniqueness :true end def fetch (count, after) count_s = count.to_s # convert count to string link = "http://reddit.com/r/aww/.json?count="+count_s+"&after="+after #so it can be used there res = HTTParty.get(link) # GET req. to the reddit server json = JSON.parse(res.body) # Parse the response if json['kind'] == "Listing" then # check if the retrieved item is a Listing for i in 1...(count) do # for each list item datum = json['data']['children'][i]['data'] #i-th element properties if datum['domain'].in?(["imgur.com", "i.imgur.com"]) then # fetch only imgur links Link.create!(author: datum['author'], url: datum['url']) # save to db end end count += 25 fetch(count, json['data']['after']) # if it retrieved the right kind of object, move on to the next page end end fetch(25," ") # run it

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• Cooperative/Non-preemptive threading avoiding threadlooks?

  - by Wayne

  Any creative ideas to avoid deadlocks on a yield or sleep with cooperative/non-preemptive multitasking without doing an O/S Thread.Sleep(10)? Typically the yield or sleep call will call back into the scheduler to run other tasks. But this can sometime produce deadlocks. Some background: This application has enormous need for speed and, so far, it's extremely fast as compared to other systems in the same industry. One of the speed techniques is cooperative/non-preemptive threading rather then the cost of a context switch from O/S threads. The high level design a priority manager which calls out to tasks depending on priority and processing time. Each task does one "iteration" of work and returns to wait its turn again in the priority queue. The tricky thing with non-preemptive threading is what to do when you want to a particular task to stop in the middle of work and wait for some other event from a different task before continuing. In this case, we have 3 tasks, A B and C where A is a controller that must synchronize the activity of B and C. First, A starts both B and C. Then B yields so C gets invoked. When C yields, A sees they are both inactive, decides it's time for B to run but not time for C yet. Well B is now stuck in a yield that has called C, so it can never run. Sincerely, Wayne

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• Write to file using CopyHere without using WScript.Sleep

  - by mlevit

  Hi guys, I've written a small VBScript to creates a .zip file and then copies the contents of a specified folder into that .zip file. I copy the files over one by one for a reason (I know I can do the whole lot at once). However my problem is when I try to copy them one by one without a WScript.Sleep between each loop iteration I get a "File not found or no read permission." error; if I place a WScript.Sleep 200 after each write it works but not 100% of the time. Pretty much I'd like to get rid of the Sleep function and not rely on that because depending on the file size it may take longer to write therefore 200 milliseconds may not be enough etc. As you can see with the small piece of code below, I loop through the files, then if they match the extension I place them into the .zip (zipFile) For Each file In folderToZip.Items For Each extension In fileExtensions if (InStr(file, extension)) Then zipFile.CopyHere(file) WScript.Sleep 200 Exit For End If Next Next Any suggestions on how I can stop relying on the Sleep function? Thanks

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• Data in linux FIFO seems lost

  - by Utoah

  Hi, I have a bash script which wants to do some work in parallel, I did this by putting each job in an subshell which is run in the background. While the number of job running simultaneously should under some limit, I achieve this by first put some lines in a FIFO, then just before forking the subshell, the parent script is required to read a line from this FIFO. Only after it gets a line can it fork the subshell. Up to now, everything works fine. But when I tried to read a line from the FIFO in the subshell, it seems that only one subshell can get a line, even if there are apparently more lines in the FIFO. So I wonder why cannot other subshell(s) read a line even when there are more lines in the FIFO. My testing code looks something like this: #!/bin/sh fifo_path="/tmp/fy_u_test2.fifo" mkfifo $fifo_path #open fifo for r/w at fd 6 exec 6 $fifo_path process_num=5 #put $process_num lines in the FIFO for ((i=0; i<${process_num}; i++)); do echo "$i" done &6 delay_some(){ local index="$1" echo "This is what u can see. $index \n" sleep 20; } #In each iteration, try to read 2 lines from FIFO, one from this shell, #the other from the subshell for i in 1 2 do date /tmp/fy_date #If a line can be read from FIFO, run a subshell in bk, otherwise, block. read -u6 echo " $$ Read --- $REPLY --- from 6 \n" /tmp/fy_date { delay_some $i #Try to read a line from FIFO read -u6 echo " $$ This is in child # $i, read --- $REPLY --- from 6 \n" /tmp/fy_date } & done And the output file /tmp/fy_date has content of: Mon Apr 26 16:02:18 CST 2010 32561 Read --- 0 --- from 6 \n Mon Apr 26 16:02:18 CST 2010 32561 Read --- 1 --- from 6 \n 32561 This is in child # 1, read --- 2 --- from 6 \n

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• Appending data to NSFetchedResultsController during find or create loop

  - by Justin Williams

  I have a table view that is managed by an NSFetchedResultsController. I am having an issue with a find-or-create operation, however. When the user hits the bottom of my table view, I am querying my server for another batch of content. If it doesn't exist in the local cache, we create it and store it. If it does exist, however, I want to append that data to the fetched results controller and display it. I can't quite figure that part out. Here's what I'm doing thus far: Passing the returned array of values from my server to an NSOperation to process. In the operation, create a new managed object context to work with. In the operation, I iterate through the array and execute a fetch request to see if the object exists (based on its server id). If the object doesn't exist, we create it and insert it into the operations' managed object context. After the iteration completes, we save the managed object context, which triggers a merge notification on my main thread. At this point, any objects that weren't locally cached in my Core Data store before will appear, but the ones that previously existed do not come along for the ride. I feel like it's something simple I'm missing, and could use a nudge in the right direction.

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• How to create a magic square in PHP?

  - by TerranRich

  I'd like to try my hand at creating a Magic Square in PHP (i.e. a grid of numbers that all add up to the same value), but I really don't know where to start. I know of the many methods that create magic square, such as starting "1" at a fixed position, then moving in a specific direction with each iteration. But that doesn't create a truly randomized Magic Square, which is what I'm aiming for. I want to be able to generate an N-by-N Magic Square of N² numbers where each row and column adds up to N(N²+1)/2 (e.g. a 5x5 square where all rows/columns add up to 65 — the diagonals don't matter). Can anybody provide a starting point? I don't want anybody to do the work for me, I just need to know how to start such a project? I know of one generator, written in Java (http://www.dr-mikes-math-games-for-kids.com/how-to-make-a-magic-square.html) but the last Java experience I had was over 10 years ago before I quickly abandoned it. Therefore, I don't really understand what the code is actually doing. I did notice, however, that when you generate a new square, it shows the numbers 1-25 (for a 5x5 square), in order, before quickly generating a fresh randomized square.

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• Iterator performance contract (and use on non-collections)

  - by polygenelubricants

  If all that you're doing is a simple one-pass iteration (i.e. only hasNext() and next(), no remove()), are you guaranteed linear time performance and/or amortized constant cost per operation? Is this specified in the Iterator contract anywhere? Are there data structures/Java Collection which cannot be iterated in linear time? java.util.Scanner implements Iterator<String>. A Scanner is hardly a data structure (e.g. remove() makes absolutely no sense). Is this considered a design blunder? Is something like PrimeGenerator implements Iterator<Integer> considered bad design, or is this exactly what Iterator is for? (hasNext() always returns true, next() computes the next number on demand, remove() makes no sense). Similarly, would it have made sense for java.util.Random implements Iterator<Double>? Should a type really implement Iterator if it's effectively only using one-third of its API? (i.e. no remove(), always hasNext())

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• Why does 12:20 PM parse to 0:20 on the next day?

  - by Hanno Fietz

  I'm using java.text.SimpleDateFormat to parse string representations of date/time values inside an XML document. I'm seeing all times that have an hour value of 12 shifted by 12 hours into the future, i. e. 20 minutes past noon gets parsed to mean 20 minutes past midnight the following day. I wrote a unit test which seems to confirm that the error is made upon parsing (I checked the return values from getTime() with the linux shell command date). Now I'm wondering: is there a bug in the parse() method? is there something wrong with the input string? am I using the wrong format string for the input? The input data is taken from Yahoo's YWeather service. Here's the test and its output: public class YWeatherReaderTest { public static final String[] rgDateSamples = { "Thu, 08 Apr 2010 12:20 PM CEST", "Thu, 08 Apr 2010 12:20 AM CEST" }; public void dateParsing() throws ParseException { DateFormat formatter = new SimpleDateFormat("EEE, dd MMM yyyy K:m a z", Locale.US); for (String dtsSrc : YWeatherReaderTest.rgDateSamples) { Date dt = formatter.parse(dtsSrc); String dtsDst = formatter.format(dt); System.out.println(dtsSrc); System.out.println(dtsDst); System.out.println(); } } } Thu, 08 Apr 2010 12:20 PM CEST Fri, 09 Apr 2010 0:20 AM CEST Thu, 08 Apr 2010 12:20 AM CEST Thu, 08 Apr 2010 0:20 PM CEST The second output line of the second iteration is slightly weird, because 00:20 isn't PM. The milliseconds value of the Date object, however, corresponds to the (wrong) time of 20 minutes past noon.

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• How to delete duplicate vectors within a multidimensional vector?

  - by David

  I have a vector of vectors: vector< vector<int> > BigVec; It contains an arbitrary number of vectors, each of an arbitrary size. I want to delete not duplicate elements of each vector, but any vectors that are the exact same as another. I don't need to preserve the order of the vectors so I can sort etc.. It should be a really simple problem to solve but I'm new to this, my (not-working) best effort: for (int i = 0; i < BigVec.size(); i++) { for (int j = 1; j < BigVec.size() ; j++ ) { if (BigVec[i][0] == BigVec [j][i]); { BigVec.erase(BigVec.begin() + j); i = 0; // because i get the impression deleting a j = 1; // vector messes up a simple iteration through } } } I think there might be a solution using Unique(), but I can't get that to work either.

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• PHPUnit - multiple stubs of same class

  - by keithjgrant

  I'm building unit tests for class Foo, and I'm fairly new to unit testing. A key component of my class is an instance of BarCollection which contains a number of Bar objects. One method in Foo iterates through the collection and calls a couple methods on each Bar object in the collection. I want to use stub objects to generate a series of responses for my test class. How do I make the Bar stub class return different values as I iterate? I'm trying to do something along these lines: $stubs = array(); foreach ($array as $value) { $barStub->expects($this->any()) ->method('GetValue')) ->will($this->returnValue($value)); $stubs[] = $barStub; } // populate stubs into `Foo` // assert results from `Foo->someMethod()` So Foo->someMethod() will produce data based on the results it receives from the Bar objects. But this gives me the following error whenever the array is longer than one: There was 1 failure: 1) testMyTest(FooTest) with data set #2 (array(0.5, 0.5)) Expectation failed for method name is equal to <string:GetValue> when invoked zero or more times. Mocked method does not exist. /usr/share/php/PHPUnit/Framework/MockObject/Mock.php(193) : eval()'d code:25 One thought I had was to use ->will($this->returnCallback()) to invoke a callback method, but I don't know how to indicate to the callback which Bar object is making the call (and consequently what response to give). Another idea is to use the onConsecutiveCalls() method, or something like it, to tell my stub to return 1 the first time, 2 the second time, etc, but I'm not sure exactly how to do this. I'm also concerned that if my class ever does anything other than ordered iteration on the collection, I won't have a way to test it.

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• Copy whole SQL Server database into JSON from Python

  - by Oli

  I facing an atypical conversion problem. About a decade ago I coded up a large site in ASP. Over the years this turned into ASP.NET but kept the same database. I've just re-done the site in Django and I've copied all the core data but before I cancel my account with the host, I need to make sure I've got a long-term backup of the data so if it turns out I'm missing something, I can copy it from a local copy. To complicate matters, I no longer have Windows. I moved to Ubuntu on all my machines some time back. I could ask the host to send me a backup but having no access to a machine with MSSQL, I wouldn't be able to use that if I needed to. So I'm looking for something that does: db = {} for table in database: db[table.name] = [row for row in table] And then I could serialize db off somewhere for later consumption... But how do I do the table iteration? Is there an easier way to do all of this? Can MSSQL do a cross-platform SQLDump (inc data)? For previous MSSQL I've used pymssql but I don't know how to iterate the tables and copy rows (ideally with column headers so I can tell what the data is). I'm not looking for much code but I need a poke in the right direction.

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• extjs how to make a nested child using xTemplate when we don't know how deep is it?

  - by Ebo the gordon

  first, sorry if my english bad,.... in my script, variable tplData below is dynamic,... (lets say it generates from database) so, every chid, can have another child. and so on,.... now, i'm stack how to iteration it,.. var tplData = [{ name : 'Naomi White' },{ name : 'Yoko Ono' },{ name : 'John Smith', child : [{ name:'Michael (John\'s son)', child: [{ name : 'Brad (Michael\'s son,John\'s grand son)' },{ name : 'Brid (Michael\'s son,John\'s grand son)', child: [{ name:'Buddy (Brid\'s son,Michael\'s grand son)' }] },{ name : 'Brud (Michael\'s son,John\'s grand son)' }] }] }]; var myTpl = new Ext.XTemplate( '<tpl for=".">', '<div style="background-color: {color}; margin: 10px;">', '<b> Name :</b> {name}<br />', // how to make this over and over every child (while it has ) '<tpl if="typeof child !=\'undefined\'">', '<b> Child : </b>', '<tpl for="child">', '{name} <br />', '</tpl>', '</tpl>', /////////////////////////////////////// '</div>', '</tpl>' ); myTpl.compile(); myTpl.overwrite(document.body, tplData);

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• In languages which create a new scope each time in a loop block, a new local copy of the local loop

  - by Jian Lin

  It seems that in language like C, Java, and Ruby (as opposed to Javascript), a new scope is created for each iteration of a loop block, and the local variable defined for the loop is actually made into a local variable every single time and recorded in this new scope? For example, in Ruby: p RUBY_VERSION $foo = [] (1..5).each do |i| $foo[i] = lambda { p i } end (1..5).each do |j| $foo[j].call() end the print out is: [MacBook01:~] $ ruby scope.rb "1.8.6" 1 2 3 4 5 [MacBook01:~] $ So, it looks like when a new scope is created, a new local copy of i is also created and recorded in this new scope, so that when the function is executed at a later time, the "i" is found in those scope chains as 1, 2, 3, 4, 5 respectively. Is this true? (It sounds like a heavy operation). Contrast that with p RUBY_VERSION $foo = [] i = 0 (1..5).each do |i| $foo[i] = lambda { p i } end (1..5).each do |j| $foo[j].call() end This time, the i is defined before entering the loop, so Ruby 1.8.6 will not put this i in the new scope created for the loop block, and therefore when the i is looked up in the scope chain, it always refer to the i that was in the outside scope, and give 5 every time: [MacBook01:~] $ ruby scope2.rb "1.8.6" 5 5 5 5 5 [MacBook01:~] $ I heard that in Ruby 1.9, i will be treated as a local defined for the loop even when there is an i defined earlier? The operation of creating a new scope, creating a new local copy of i each time through the loop seems heavy, as it seems it wouldn't have matter if we are not invoking the functions at a later time. So when the functions don't need to be invoked at a later time, could the interpreter and the compiler to C / Java try to optimize it so that there is not local copy of i each time?

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• How to create a Binary Tree from a General Tree?

  - by mno4k

  I have to solve the following constructor for a BinaryTree class in java: BinaryTree(GeneralTree<T> aTree) This method should create a BinaryTree (bt) from a General Tree (gt) as follows: Every Vertex from gt will be represented as a leaf in bt. If gt is a leaf, then bt will be a leaf with the same value as gt If gt is not a leaf, then bt will be constructed as an empty root, a left subTree (lt) and a right subTree (lr). Lt is a stric binary tree created from the oldest subtree of gt (the left-most subtree) and lr is a stric binary tree created from gt without its left-most subtree. The frist part is trivial enough, but the second one is giving me some trouble. I've gotten this far: public BinaryTree(GeneralTree<T> aTree){ if (aTree.isLeaf()){ root= new BinaryNode<T>(aTree.getRootData()); }else{ root= new BinaryNode<T>(null); // empty root LinkedList<GeneralTree<T>> childs = aTree.getChilds(); // Childs of the GT are implemented as a LinkedList of SubTrees child.begin(); //start iteration trough list BinaryTree<T> lt = new BinaryTree<T>(childs.element(0)); // first element = left-most child this.addLeftChild(lt); aTree.DeleteChild(hijos.elemento(0)); BinaryTree<T> lr = new BinaryTree<T>(aTree); this.addRightChild(lr); } } Is this the right way? If not, can you think of a better way to solve this? Thank you!

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• Implementing subtables in JSF 1.1

  - by Xenon

  We're looking for a way to implement subtables in JSF 1.1. We cannot use Rich Faces due to the fact that out target server is WebSphere 6.1. I've tried JSTL and Tomahawk to no avail. Also, our project is using JSP's and not facelets. Here's my HTML/JSTL example: <table border="1" width="700px"> Header 1 Header 2 Header 3 Header 4 Header 5 ${item.value1} ${item.value2} ${item.value3} ${item.value4} ${item.value5} <tr> <td colspan="5"> <table border="1" width="100%"> <thead> <tr> <td>SubHeader 1</td> <td>SubHeader 2</td> <td>SubHeader 3</td> <td>SubHeader 4</td> <td>SubHeader 5</td> </tr> </thead> <!-- For loop iteration over subtable data --> <c:forEach var="subitem" items="${item.subtable}"> <tr> <td>${subitem.value1}</td> <td>${subitem.value2}</td> <td>${subitem.value2}</td> <td>${subitem.value2}</td> <td>${subitem.value2}</td> </tr> </c:forEach> </table> </td> </tr>

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• How to retrieve value from ViewData when the object is not a string?

  - by Richard77

  Hello, Here's the functionality I'd like to exploit: I've a class myClass and would like to iterate over a collection that contains all the properties of that class. I'd like to send the index of that collection along with the other data so that I can control the each sequence of the iteration. Here's simplified versions of a Action method and View (I'll use the same action-view for that functionality). 1) Action public ActionResult CreateHierarchy(int? index) { if(index < PropertiesOfMyClass.Lenght) { //Other code omitted ViewData["index"] = ((index == null) ? 1 : index++); Return View(); } } 2)View <% Using(Html.BeginForm()){%> //Other Code omitted <% = Html.Hidden("Index", ViewData["index"])%> <input type = "submit" value = "Do someting"/> <%}%> I've also placed this at the bottom of the page so that I can check the value of the index, <% = ViewData["index"]%> Unfortunately, its not working. I'm getting only the number 1. I'm missing something? such as a cast for the Viewdata? Should I write something like this: <% = Html.Hidden("index", (int)ViewData["index"])%> It's not working either Thanks for helping

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• syntax help required on templated static member function

  - by omatai

  I have a bunch of containers of object pointers that I want to iterate through in different contexts to produce diagnostics for them. I'm struggling with the syntax required to define the functions... which, on account of these objects filtering through diverse parts of my application, seem best encapsulated in a dedicated diagnostics class thus: // Code sketch only - detail fleshed out below... class ObjectListDiagnoser { public: static void GenerateDiagnostics( /* help required here! */ ); }; ... // Elsewhere in the system... ObjectListDiagnoser::GenerateDiagnostics( /* help required here! */ ); What I'd like to be able to do (in places across my application) is at least this: std::vector<MyObject *> objGroup1; std::list<MyObject *> objGroup2; ObjectListDiagnoser::GenerateDiagnostics( objGroup1.begin(), objGroup1.end() ); ObjectListDiagnoser::GenerateDiagnostics( objGroup2.begin(), objGroup2.end() ); ObjectListDiagnoser::GenerateDiagnostics( objGroup1.rbegin(), objGroup1.rend() ); I have tried to template my function in two ways, with no success: class ObjectListDiagnoser { public: // 1 - nope. template <class ObjIter> static void GenerateDiagnostics( ObjIter first, ObjIter last ); // 2. - nope. template <class Container, class ObjIter> static void GenerateDiagnostics( Container<MyObject *>::ObjIter first, Container<MyObject *>::ObjIter last ); }; Can someone provide the correct syntax for this? The container type will vary, and the direction of iteration will vary, but always for the same type of object.

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• Assign a unique client ID to each <rich:dataTable /> row?

  - by Dolph Mathews

  I'm relatively new to working with the UI in Seam, so I'm hoping there is something simple I can replace the three instances of UNIQUE_ID with in the following example (such as #{object.uniqueId}). The goal is to have a <rich:dataTable /> wherein each row has the ability to show/hide a <rich:modalPanel /> with more details about the particular object instance. <rich:dataTable var="object" value="#{bean.myObject}"> <rich:column> <h:outputText value="#{object.summary}" /> </rich:column> <rich:column> <a onclick="Richfaces.showModalPanel('UNIQUE_ID');" href="#">Show Details in ModalPanel</a> <a4j:form> <rich:modalPanel id="UNIQUE_ID" > <a onclick="Richfaces.hideModalPanel('UNIQUE_ID');" href="#">Hide This ModalPanel</a> <h:outputText value="#{object.details}" /> </rich:modalPanel> </a4j:form> </rich:column> </rich:dataTable> If I only had one link/modalPanel pair, this would obviously be trivial, but I don't know what to do within the scope of the <rich:dataTable />'s iteration. Also, in case it complicates things further, the page will also contain many <rich:dataTable />'s, each implementing this behavior.

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• What is the best way to iterate over a large result set in JDBC/iBatis 3?

  - by paul_sns

  We're trying to iterate over a large number of rows from the database and convert those into objects. Behavior will be as follows: Result will be sorted by sequence id, a new object will be created when sequence id changes. The object created will be sent to an external service and will sometimes have to wait before sending another one (which means the next set of data will not be immediately used) We already have invested code in iBatis 3 so an iBatis solution will be the best approach for us (we've tried using RowBounds but haven't seen how it does the iteration under the hood). We'd like to balance minimizing memory usage and reducing number of DB trips. We're also open to pure JDBC approach but we'd like the solution to work on different databases. UPDATE: We need to make as few calls to DB as possible (1 call would be the ideal scenario) while also preventing the application to use too much memory. Are there any other solutions out there for this type of problem may it be pure JDBC or any other technology? Thanks and hope to hear your insights on this.

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• jQuery - Callback failing if there is no options parameter

  - by user249950

  Hi, I'm attempting to build a simple plugin like this (function($) { $.fn.gpSlideOut = function(options, callback) { // default options - these are used when no others are specified $.fn.gpSlideOut.defaults = { fadeToColour: "#ffffb3", fadeToColourSpeed: 500, slideUpSpeed: 400 }; // build main options before element iteration var o = $.extend({}, $.fn.gpSlideOut.defaults, options); this.each(function() { $(this) .animate({backgroundColor: o.fadeToColour},o.fadeToColourSpeed) .slideUp(o.SlideUpSpeed, function(){ if (typeof callback == 'function') { // make sure the callback is a function callback.call(this); // brings the scope to the callback } }); }); return this; }; // invoke the function we just created passing it the jQuery object })(jQuery); The confusion I'm having is that normally on jQuery plugins you can call something like this: $(this_moveable_item).gpSlideOut(function() { // Do stuff }); Without the options parameter, but it misses the callback if I do it like that so I have to always have var options = {} $(this_moveable_item).gpSlideOut(options, function() { // Do stuff }); Even if I only want to use the defaults. Is there anyway to make sure the callback function is called whether or not the options parameter is there? Cheers.

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• "multiply frog enemy" timer and array AS3

  - by VideoDnd

  How can I use the counter value to multiply the frogs in the array? My counter goes from 0-100. I want to prove that I can increment the enemies using a counter. EXPLAINED BETTER I have 10 frogs in an array. I want to use a timer to add 10 more frogs on each iteration of the TimerEvent.TIMER firing. //currentCount var timer:Timer = new Timer(1000, 50); timer.addEventListener(TimerEvent.TIMER, countdown); timer.start(); function countdown(event:TimerEvent) { // myText.text = String(0 + timer.currentCount); } //Creates 10 enemies "I want enemies to multiply 0-100" var enemyArray:Array = new Array(); for (var i:int = 0; i < 10; i++) { var noname:FrogClass = new FrogClass(); noname.x = i*10; //this will just assign some different x and y value depending on i. noname.y = i*11; enemyArray.push(noname); //put the enemy into the array addChild(noname); //puts it on the stage } SYMBOL PROPERTIES NAME "noname" CLASS "FrogClass" WHY I need specific examples using strings and arrays, because I'm stuck in a learning curve. Stupid examples are more fun!

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• Python access an object byref / Need tagging

  - by Aaron C. de Bruyn

  I need to suck data from stdin and create a object. The incoming data is between 5 and 10 lines long. Each line has a process number and either an IP address or a hash. For example: pid=123 ip=192.168.0.1 - some data pid=123 hash=ABCDEF0123 - more data hash=ABCDEF123 - More data ip=192.168.0.1 - even more data I need to put this data into a class like: class MyData(): pid = None hash = None ip = None lines = [] I need to be able to look up the object by IP, HASH, or PID. The tough part is that there are multiple streams of data intermixed coming from stdin. (There could be hundreds or thousands of processes writing data at the same time.) I have regular expressions pulling out the PID, IP, and HASH that I need, but how can I access the object by any of those values? My thought was to do something like this: myarray = {} for each line in sys.stdin.readlines(): if pid and ip: #If we can get a PID out of the line myarray[pid] = MyData().pid = pid #Create a new MyData object, assign the PID, and stick it in myarray accessible by PID. myarray[pid].ip = ip #Add the IP address to the new object myarray[pid].lines.append(data) #Append the data myarray[ip] = myarray[pid] #Take the object by PID and create a key from the IP. <snip>do something similar for pid and hash, hash and ip, etc...</snip> This gives my an array with two keys (a PID and an IP) and they both point to the same object. But on the next iteration of the loop, if I find (for example) an IP and HASH and do: myarray[hash] = myarray[ip] The following is False: myarray[hash] == myarray[ip] Hopefully that was clear. I hate to admit that waaay back in the VB days, I remember being able handle objects byref instead of byval. Is there something similar in Python? Or am I just approaching this wrong?

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• multithreading issue

  - by vbNewbie

  I have written a multithreaded crawler and the process is simply creating threads and having them access a list of urls to crawl. They then access the urls and parse the html content. All this seems to work fine. Now when I need to write to tables in a database is when I experience issues. I have 2 declared arraylists that will contain the content each thread parse. The first arraylist is simply the rss feed links and the other arraylist contains the different posts. I then use a for each loop to iterate one while sequentially incrementing the other and writing to the database. My problem is that each time a new thread accesses one of the lists the content is changed and this affects the iteration. I tried using nested loops but it did not work before and this works fine using a single thread.I hope this makes sense. Here is my code: SyncLock dlock For Each l As String In links finallinks.Add(l) Next End SyncLock SyncLock dlock For Each p As String In posts finalposts.Add(p) Next End SyncLock ... Dim i As Integer = 0 SyncLock dlock For Each rsslink As String In finallinks postlink = finalposts.Item(i) i = i + 1 finallinks and finalposts are the two arraylists. I did not include the rest of the code which shows the threads working but this is the essential part where my error occurs which is basically here postlink = finalposts.Item(i) i = i + 1 ERROR: index was out of range. Must be non-negative and less than the size of the collection Is there an alternative?

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