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• Split large repo into multiple subrepos and preserve history (Mercurial)

  - by Andrew

  We have a large base of code that contains several shared projects, solution files, etc in one directory in SVN. We're migrating to Mercurial. I would like to take this opportunity to reorganize our code into several repositories to make cloning for branching have less overhead. I've already successfully converted our repo from SVN to Mercurial while preserving history. My question: how do I break all the different projects into separate repositories while preserving their history? Here is an example of what our single repository (OurPlatform) currently looks like: /OurPlatform ---- Core ---- Core.Tests ---- Database ---- Database.Tests ---- CMS ---- CMS.Tests ---- Product1.Domain ---- Product1.Stresstester ---- Product1.Web ---- Product1.Web.Tests ---- Product2.Domain ---- Product2.Stresstester ---- Product2.Web ---- Product2.Web.Tests ==== Product1.sln ==== Product2.sln All of those are folders containing VS Projects except for the solution files. Product1.sln and Product2.sln both reference all of the other projects. Ideally, I'd like to take each of those folders, and turn them into separate Hg repos, and also add new repos for each project (they would act as parent repos). Then, If someone was going to work on Product1, they would clone the Product1 repo, which contained Product1.sln and subrepo references to ReferenceAssemblies, Core, Core.Tests, Database, Database.Tests, CMS, and CMS.Tests. So, it's easy to do this by just hg init'ing in the project directories. But can it be done while preserving history? Or is there a better way to arrange this?

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• Switch between multiple views while respecting orientation

  - by zoul

  Hello! I have an MVC application with a single model and several views (something like skins). I want the user to be able to switch the views and I can’t get it working with interface orientation. The most simple approach looks like this: - (void) switchToADifferentView: (UIView*) newView { // self is a descendant of UIViewController self.view = newView; } This does not work because the incoming view does not get rotated according to current orientation (until the next orientation change, test case). Is there a way to force the orientation on a view? It looks like the system is trying really hard to keep the interface controls for itself. (Or is it as simple as setting the right transform by hand?) I figured I’d better not switch the views directly and switch controllers instead. This makes sense, as it makes the initial code simpler. But how do I switch controllers that have no “navigation relation” between them? I guess I could use presentModalViewController:, but that seems like a hack. Same goes for navigation controller. If I exchange the controllers by hand, I get the wrong orientation again: - (void) switchToAController: (id) incoming { [currentController.view removeFromSuperview]; [window addSubview:incoming.view]; // does not respect current orientation } Now how the heck do I simply exchange the current controller for another one? Again, the controllers are something like “skins” operating above a shared model, so it really makes no sense to pretend that skin A is a “modal” dialog above skin B or that they’re a part of a navigation stack.

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• Security implications of writing files using PHP

  - by susmits

  I'm currently trying to create a CMS using PHP, purely in the interest of education. I want the administrators to be able to create content, which will be parsed and saved on the server storage in pure HTML form to avoid the overhead that executing PHP script would incur. Unfortunately, I could only think of a few ways of doing so: Setting write permission on every directory where the CMS should want to write a file. This sounds like quite a bad idea. Setting write permissions on a single cached directory. A PHP script could then include or fopen/fread/echo the content from a file in the cached directory at request-time. This could perhaps be carried out in a Mediawiki-esque fashion: something like index.php?page=xyz could read and echo content from cached/xyz.html at runtime. However, I'll need to ensure the sanity of $_GET['page'] to prevent nasty variations like index.php?page=http://www.bad-site.org/malicious-script.js. I'm personally not too thrilled by the second idea, but the first one sounds very insecure. Could someone please suggest a good way of getting this done?

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• How to unit test this simple ASP.NET MVC controller

  - by Frank Schwieterman

  Lets say I have a simple controller for ASP.NET MVC I want to test. I want to test that a controller action (Foo, in this case) simply returns a link to another action (Bar, in this case). How would you test this? (either the first or second link) My implementation has the same link twice. One passes the url throw ViewData[]. This seems more testable to me, as I can check the ViewData collection returned from Foo(). Even this way though, I don't know how to validate the url itself without making dependencies on routing. The controller: public class TestController : Controller { public ActionResult Foo() { ViewData["Link2"] = Url.Action("Bar"); return View("Foo"); } public ActionResult Bar() { return View("Bar"); } } the "Foo" view: <%@ Page Title="" Language="C#" Inherits="System.Web.Mvc.ViewPage" MasterPageFile="~/Views/Shared/Site.Master"%> <asp:Content ContentPlaceHolderID="MainContent" runat="server"> <%= Html.ActionLink("link 1", "Bar") %> <a href="<%= ViewData["Link2"]%>">link 2</a> </asp:Content>

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• Why is cell phone software is still so primitive?

  - by Tomislav Nakic-Alfirevic

  I don't do mobile development, but it strikes me as odd that features like this aren't available by default on most phones: full text search: searches all address book contents, messages, anything else being a plus better call management: e.g. a rotating audio call log, meaning you always have the last N calls recorded for your listening pleasure later (your little girl just said her first "da-da" while you were on a business trip, you had a telephone job interview, you received complex instructions to do something etc.) bluetooth remote control (like e.g. anyRemote, but available by default on a bluetooth phone) no multitasking capabilities worth mentioning and in general no e.g. weekly software updates, making the phone much more usable (even if it had to be done over USB, rather than over the network). I'm sure I was dumbfounded by the lack or design of other features as well, but they don't come to mind right now. To clarify, I'm not talking about smartphones here: my plain, 2-year old phone has a CPU an order of magnitude faster than my first PC, about as much storage space and it's ridiculous how bad (slow, unwieldy) the software is and it's not one phone or one manufacturer. What keeps the (to me) obvious software functionality vacuum on a capable hardware platform from being filled up?

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• Unpacking gems [Rails 2.3.5]

  - by yuval

  I have the following gems defined in my environment.rb file: config.gem "authlogic" config.gem "paperclip" config.gem "pauldix-feedzirra", :lib => "feedzirra", :source => "http://gems.github.com" config.gem 'whenever', :lib => false, :source => 'http://gemcutter.org/' I have them installed on my local computer and everything is working well. Since I am working on a shared-server (DreamHost), I need to unpack those gems to get them to work (can't install them as I did on my own computer to get them to work). Before uploading, I ran the following on my local machine: rake gems:unpack This created the following folders in /vender/gems: authlogic-2.1.3, paperclip-2.3.1.1, pauldix-feedzirra-0.0.18, whenever-0.4.1 So it looks like they're all there. When I run rake db:migrate on the server, though, I get these following error: Missing these required gems: pauldix-feedzirra For some reason, the feedzirra unpacked gem is not detected. Could anybody give me a clue as to why this is happening and how to solve it? Thanks!

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• Does HttpListener work well on Mono?

  - by billpg

  Hi everyone. I'm looking to write a small web service to run on a small Linux box. I prefer to code in C#, so I'm looking to use Mono. I don't want the overhead of running a full web server or Mono's version of ASP.NET. I'm thinking of having a single process with a thread dealing with each client connection. Shared memory between threads instead of a database. I've read a little on Microsoft's version of HttpListener and how it works with the Http.sys driver. Alas, Mono's documentation on this class is just the automated class interface with no discussion of how it works under the hood. (Linux doesn't have Http.sys, so I imagine it's implemented substantially differently.) Could anyone point me towards some resources discussing this module please? Many thanks, Bill, billpg.com (A little background to my question for the interested.) Some time ago, I asked this question, interested in keeping a long conversation open with lots of back-and-forth. I had settled on designing my own ad-hoc protocol, but people I spoke to really wanted a REST interface, even at the cost of the "Okay, send your command now" signal. So, I wondered about running ASP.NET on a Linux/Mono server, but stumbled upon HttpListener. This seemed ideal, as each "conversation" could run in a separate thread. The thread that calls HttpListener in a loop can look for which thread each incomming connection is for and pass the reference to that thread. The alternative for an ASP.NET driven service, would be to have the ASPX code pick up the state from a database, and write back the new state when it finishes. Yes, it would work, but that's a lot of overhead.

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• Why won't VS2010 RC use my existing types when I add a service reference?

  - by Johan Driessen

  I have a huge problem getting services references in VS2010 RC to use existing assemblies. Even though I have a class library with all the data contracts (classes marked with DataContract and properties with DataMember) that is shared between the service project and the consuming project (which is a class library), when I add a service reference, the data contracts are regenerated withing the service reference instead of using the existing types. When I was using VS2010 beta 2, this worked fine, and I have existing service references using the very same data contracts. But if I add a new service reference, or even update an old one, it won't use the existing types anymore. I have made a mini-test-solution, with one service, one data contract type and one console app as a consumer (all in the same solution), and there it seems to work, but that's no great comfort to me. Is there any way to see why it can't use the existing types? Edit to clearify. It works to generate the proxy classes with svcutil.exe, and point to the data contracts dll, like this: svcutil.exe http://localhost/MyService.svc /reference:[Path To DataContracts]\DataContracts.dll /n:*,MyProject.MyServiceReference /ct:System.Collections.Generic.List`1 The question is, what possible reason could there be for Visual Studio to generate its own datacontracts instead of using the existing ones even though the "reuse" checkbox is checked and the datacontracts assembly is referenced.

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• permutations gone wrong

  - by vbNewbie

  I have written code to implement an algorithm I found on string permutations. What I have is an arraylist of words ( up to 200) and I need to permutate the list in levels of 5. Basically group the string words in fives and permutated them. What I have takes the first 5 words generates the permutations and ignores the rest of the arraylist? Any ideas appreciated. Private Function permute(ByVal chunks As ArrayList, ByVal k As Long) As ArrayList ReDim ItemUsed(k) pno = 0 Permutate(k, 1) Return chunks End Function Private Shared Sub Permutate(ByVal K As Long, ByVal pLevel As Long) Dim i As Long, Perm As String Perm = pString ' Save the current Perm ' for each value currently available For i = 1 To K If Not ItemUsed(i) Then If pLevel = 1 Then pString = chunks.Item(i) 'pString = inChars(i) Else pString = pString & chunks.Item(i) 'pString += inChars(i) End If If pLevel = K Then 'got next Perm pno = pno + 1 SyncLock outfile outfile.WriteLine(pno & " = " & pString & vbCrLf) End SyncLock outfile.Flush() Exit Sub End If ' Mark this item unavailable ItemUsed(i) = True ' gen all Perms at next level Permutate(K, pLevel + 1) ' Mark this item free again ItemUsed(i) = False ' Restore the current Perm pString = Perm End If Next K above is = to 5 for the number of words in one permutation but when I change the for loop to the arraylist size I get an error of index out of bounds

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• How do I import and call unmanaged C dll with ansi string "char *" pointer string from VB.net?

  - by Warren P

  I have written my own function, which in C would be declared like this, using standard Win32 calling conventions: int Thing( char * command, char * buffer, int * BufSize); I have the following amount of VB figured out, which should import the dll and call this function, wrapping it up to make it easy to call Thing("CommandHere",GetDataBackHere): Imports Microsoft.VisualBasic Imports System.Runtime.InteropServices Imports System Imports System.Text Namespace dllInvocationSpace Public Class dllInvoker ' tried attributes but could not make it build: ' <DllImport("Thing1.dll", False, CallingConvention.Cdecl, CharSet.Ansi, "Baton", True, True, False, True)> Declare Ansi Function Thing Lib "Thing1.dll" (ByVal Command As String, ByRef Buffer As String, ByRef BufferLength As Integer) Shared Function dllCall(ByVal Command As String, ByRef Results As String) As Integer Dim Buffer As StringBuilder = New StringBuilder(65536) Dim retCode As Integer Dim bufsz As Integer bufsz = 65536 retCode = Thing(Command, Buffer, bufsz) Results = Buffer Return retCode End Function End Class End Namespace The current code doesn't build, because although I think I should be able to create a "buffer" that the C Dll can write data back into using a string builder, I haven't got it quite right. (Value of type System.Text.STringBuilder cannot be converted to 'String'). I have looked all over the newsgroups and forums and can not find an example where the C dll needs to pass between 1 and 64kbytes of data back (char *buffer, int bufferlen) to visual basic.net.

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• How to properly force a Blackberry Java application to install using Loader.exe

  - by Kevin White

  I want to include the Application Loader process in a software installation, to ensure that users get our software installed on their Blackberry by the time our installer software finishes. I know this is possible, because Aerize Card Loader (http://aerize.com/blackberry/software/loader/) does this. When you install their software, if your Blackberry is connected the Application Loader will come up and force the .COD file to install to the device. I can't make it work. Looking at RIM's own documentation, I need to: Place the ALX and COD files into a subfolder here: C:\Program Files\Common Files\Research In Motion\Shared\Applications\ Add a path to the ALX file in HKCU\Software\Research In Motion\Blackberry\Loader\Packages Index the application, by executing this at the command line: loader.exe /index Start the force load, by doing this: loader.exe /defaultUSB /forceload When I execute that last command, the Application Loader comes up and says that all applications are up to date and nothing needs to be done. If I execute loader.exe by double-clicking on it (or typing in the command with no parameters), I get the regular Application Loader wizard. It shows my program as listed, but un-checked. If I check it and click next, it will install to the Blackberry. (This is the part that I want to avoid, and that Aerize Card Loader's install process avoids.) What am I missing? It appears that the Aerize installer is doing something different but I haven't been able to ascertain what.

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• .NET assembly loading problem

  - by Simon

  I'm maintaining the build process for our application which consist of an ASP.Net application, two different Win32 services and other sysadmin related applications. I want to end up with the following configuration to be used both when debugging & deploying. libraires/ -- Contains shared assemblies used by all other apps. web/ -- ASP.Net site service1/ -- Win32 service 1 (seen under the service control manager) service2/ -- Win32 service 2 adminstuff/ -- Sysadmin / support stuff used for troubleshooting The problem is assembly probing privatePath in the app.config does not support relative directories outside the application root. Ie: can't use ../libraries. Very frustating... If I strong name our assemblies, I could use codeBase config element which seems to support absolute path but you need to specify each assembly individually. I also tried hooking into AppDomain.AssemblyResolve event, but I'm getting FileNotFoundException from the .Net Fusion before I can even register the event handler in Main(). I don't like the idea of registering the assemblies in the GAC. Too much hassle when deploying / upgrading application. Is there another to do this without having the specify the path of each requiered assembly ?

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• How do attribute classes work?

  - by AaronLS

  My searches keep turning up only guides explaining how to use and apply attributes to a class. I want to learn how to create my own attribute classes and the mechanics of how they work. How are attribute classes instantiated? Are they instantiated when the class they are applied to is instantiated? Is one instantiated for each class instantiated that it is applied to? E.g. if I apply the SerializableAttribute class to a MyData class, and I instantiate 5 MyData instances, will there be 5 instances of the SerializbleAttribute class created behind the scenes? Or is there just one instance shared between all of them? How do attribute class instances access the class they are associated with? How does a SerializableAttribute class access the class it is applied to so that it can serialize it's data? Does it have some sort of SerializableAttribute.ThisIsTheInstanceIAmAppliedTo property? :) Or does it work in the reverse direction that whenever I serialize something, the Serialize function I pass the MyClass instance to will reflectively go through the Attributes and find the SerialiableAttribute instance?

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• Design suggestions for creating document management structure using hidden shares.

  - by focus.nz

  I need to add some document management functionality into my software. Documents will be grouped by company name and project name. The folders need to be accessed by the application using the id numbers of clients/projects, but also easily browsed by the end user using windows explorer. Clients and Projects will be stored in a database. I am thinking of having the software create the folders using the friendly name and then using a hidden share with the id number for the software to access the files. The folder structure would be something like this --Company 1 (Company-1234$) -- Project 101 (Project-101$) -- Project 102 (Project-102$) -- Project 103 (Project-103$) -- Company 2 (Company-5678$) -- Project 201 (Project-201$) -- Project 202 (Project-202$) -- Project 203 (Project-203$) So in the example above there would be a company called "Company 1" with a ID of "1234". When browsing the folders using windows explorer the user would see \\ServerName\Documents\Company1 and you could also access the same folder from \\ServerName\Documents\Company-1234$ By using the hidden share, if the company name changes or its renamed for some reason it doesn't break the link in the application because its using the hidden shared based on the ID that never changes. Will having hundreds (maybe thousands) or hidden shares on a server provide a huge performance hit? Does any one have any suggestions or alternatives to provide this feature?

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• WPD on XP, Vista, and 7 (need to transfer photo and video files)

  - by Bradley Dean

  I need to transfer files (still photos and videos) from any portable device that a user may connect (still camera, video camera, mobile phone, etc.) I don't need to worry about plain storage devices as these have drive letters. And I only care about existing files, I don't care about live video, preview video, taking new pictures, etc. I originally tried WIA, which works great except it can not transfer video files. So then I tried WPD, following along with dimeby8's tutorial: http://blogs.msdn.com/b/dimeby8/archive/2006/09/27/774259.aspx I haven't gotten the transfer working yet (I'm converting it over to C#), but I can at least see the device and enumerate the files in Win7. In XP I get nothing. It's pointed out in this thread that WPD won't enumerate devices on XP (see Lisa O [MSFT]'s post): http://social.msdn.microsoft.com/Forums/en/windowssdk/thread/56459945-b757-45df-8c9f-4ebdbbb18a2c So WIA is out because it won't do video. And WPD is out because it won't do XP. Has anyone gotten this to work? Am I missing something simple here? Thanks.

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• A map and set which uses contiguous memory and has a reserve function

  - by edA-qa mort-ora-y

  I use several maps and sets. The lack of contiguous memory, and high number of (de)allocations, is a performance bottleneck. I need a mainly STL-compatbile map and set class which can use a contiguous block of memory for internal objects (or multiple blocks). It also needs to have a reserve function so that I can preallocate for expected sizes. Before I write my own I'd like to check what is available first. Is there something in Boost which does this? Does somebody know of an available implementation elsewhere? Intrusive collection types are not usable here as the same objects need to exist in several collections. As far as I know STL memory pools are per-type, not per instance. These global pools are not efficient with respect to memory locality in mutli-cpu/core processing. Object pools don't work as the types will be shared between instance but their pool should not. In many cases a hash map may be an option in some cases.

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• jsTree: How to create a new ID for the new added node?

  - by marknt15

  Hi, I can normally get the ID of the default tree nodes but my problem is onCreate then jsTree will add a new node but it doesn't have an ID. My question is how can I add an ID to the newly created tree node? What I'm thinking to do is adding the ID HTML attribute to the newly created tree node but how? I need to get the ID of all of the nodes because it will serve as a reference for the node's respective div storage. HTML code: <div class="demo" id="demo_1"> <ul> <li id="phtml_1" class="file"><a href="#"><ins>&nbsp;</ins>Root node 1</a></li> <li id="phtml_2" class="file"><a href="#"><ins>&nbsp;</ins>Root node 2</a></li> </ul> </div> JS code: $("#demo_1").tree({ ui : { theme_name : "apple" }, callback : { onrename : function (NODE, TREE_OBJ) { alert(TREE_OBJ.get_text(NODE)); alert($(NODE).attr('id')); } } }); Cheers, Mark

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• How to make a mapped field inherited from a superclass transient in JPA?

  - by Russ Hayward

  I have a legacy schema that cannot be changed. I am using a base class for the common features and it contains an embedded object. There is a field that is normally mapped in the embedded object that needs to be in the persistence id for only one (of many) subclasses. I have made a new id class that includes it but then I get the error that the field is mapped twice. Here is some example code that is much simplified to maintain the sanity of the reader: @MappedSuperclass class BaseClass { @Embedded private Data data; } @Entity class SubClass extends BaseClass { @EmbeddedId private SubClassId id; } @Embeddable class Data { private int location; private String name; } @Embeddable class SubClassId { private int thingy; private int location; } I have tried @AttributeOverride but I can only get it to rename the field. I have tried to set it to updatable = false, insertable = false but this did not seem to work when used in the @AttributeOverride annotation. See answer below for the solution to this issue. I realise I could change the base class but I really do not want to split up the embedded object to separate the shared field as it would make the surrounding code more complex and require some ugly wrapping code. I could also redesign the whole system for this corner case but I would really rather not. I am using Hibernate as my JPA provider.

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• Would it be possible to have a UTF-8-like encoding limited to 3 bytes per character?

  - by dan04

  UTF-8 requires 4 bytes to represent characters outside the BMP. That's not bad; it's no worse than UTF-16 or UTF-32. But it's not optimal (in terms of storage space). There are 13 bytes (C0-C1 and F5-FF) that are never used. And multi-byte sequences that are not used such as the ones corresponding to "overlong" encodings. If these had been available to encode characters, then more of them could have been represented by 2-byte or 3-byte sequences (of course, at the expense of making the implementation more complex). Would it be possible to represent all 1,114,112 Unicode code points by a UTF-8-like encoding with at most 3 bytes per character? If not, what is the maximum number of characters such an encoding could represent? By "UTF-8-like", I mean, at minimum: The bytes 0x00-0x7F are reserved for ASCII characters. Byte-oriented find / index functions work correctly. You can't find a false positive by starting in the middle of a character like you can in Shift-JIS.

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• How to run White + SL4 UATs through TeamCity?

  - by Duncan Bayne

  After experiencing a series of unpleasant issues with TFS, including source code orruption and project management inflexibility, we (meaning the project team of which I'm a part) have decided to move from TFS 2010 to TeamCity + SVN + V1. I've managed to get our MSTest component and unit tests running as part of every build. However, our UATs are failing, and I was hoping for some advice from the TeamCity community as to best practices w.r.t. running web servers and interacting with the desktop. Each of our UAT fixtures starts a web server to host the site, like this: public static void StartWebServer() { var pathToSite = @"C:\projects\myproject\FrontEnd\MyProject.FrontEnd.Web"; var webServer = new Process { StartInfo = new ProcessStartInfo { Arguments = string.Format("/port:9150 /path:\"{0}\"", pathToSite), FileName = @"C:\Program Files (x86)\Common Files\microsoft shared\DevServer\10.0\WebDev.WebServer40.EXE" } }; webServer.Start(); } Needless to say, this doesn't work when running through TeamCity, as the pathToSite value is different each time. I'm hoping there is a way of determining the path into which the the code is checked out prior to building? That would allow me to point the web server at the right place. The other issue is that our UATs use White to drive the Silverlight UI through an instance of Internet Explorer: _browserWindow = InternetExplorer.Launch("http://localhost:9150/index.html#/Home", "Home - Windows Internet Explorer"); _document = _browserWindow.SilverlightDocument; I've ensured that the TeamCity service is granted the ability to interact with the desktop, and I've set the build agent machine up to log in automatically (an open session is a pre-requisite for White to work properly). Is that all I need to do or are there additional steps required?

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• modifying ajax returned data before showing

  - by Nick

  I'm processing subscribtion form with jQuery/ajax and need to display results with success function (they are different depending on if email exists in database). But the trick is I do not need h2 and first "p" tag. How can I show only div#alertmsg and second "p" tag? I've tried revoming unnecessary elements with method described here, but it didn't work. Thanks in advance. Here is my code: var dataString = $('#subscribe').serialize(); $.ajax({ type: "POST", url: "/templates/willrock/pommo/user/process.php", data: dataString, success: function(data){ var result = $(data); $('#success').append(result); } Here is the data returned: <h2>Subscription Review</h2> <p><a href="url" onClick="history.back(); return false;"><img src="/templates/willrock/pommo/themes/shared/images/icons/back.png" alt="back icon" class="navimage" /> Back to Subscription Form</a></p> <div id="alertmsg" class="error"> <ul> <li>Email address already exists. Duplicates are not allowed.</li> </ul> </div> <p><a href="login.php">Update your records</a></p>

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• Using WCF to expose underlying process

  - by Steven

  I think I must be a little dull because I'm having so much difficulty with this. I use WCF for pretty much everything in-house, it's the most appropriate technology. I have a new Silverlight 3 app that is connecting to the WCF service and that's working fine. Where the problem begins is: Because of the expense in creating the objects within this service and the high correlation of individual objects being shared between clients I want to have a console application that basically gathers/calculates/caches all the data for the service 24/7 and the service basically connects to the console app (or whatever it is) and gets the pre-processed data. eg, think of it in terms of a stock reporting app (which it is). Person A has a portfolio of x, y z Person B has a portfolio of x, q, z, r The service needs to provide updated metrics on how their portfolio is performing. So instead of every 1 second processing person A, then person B, the app independently gathers the stock price and persons position information into memory and the service just queries the in memory result. Thanks for your help, I really am feeling dumb right now.

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• Quickest algorithm for finding sets with high intersection

  - by conradlee

  I have a large number of user IDs (integers), potentially millions. These users all belong to various groups (sets of integers), such that there are on the order of 10 million groups. To simplify my example and get to the essence of it, let's assume that all groups contain 20 user IDs (i.e., all integer sets have a cardinality of 100). I want to find all pairs of integer sets that have an intersection of 15 or greater. Should I compare every pair of sets? (If I keep a data structure that maps userIDs to set membership, this would not be necessary.) What is the quickest way to do this? That is, what should my underlying data structure be for representing the integer sets? Sorted sets, unsorted---can hashing somehow help? And what algorithm should I use to compute set intersection)? I prefer answers that relate C/C++ (especially STL), but also any more general, algorithmic insights are welcome. Update Also, note that I will be running this in parallel in a shared memory environment, so ideas that cleanly extend to a parallel solution are preferred.

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• If attacker has original data and encrypted data, can they determine the passphrase?

  - by Brad Cupit

  If an attacker has several distinct items (for example: e-mail addresses) and knows the encrypted value of each item, can the attacker more easily determine the secret passphrase used to encrypt those items? Meaning, can they determine the passphrase without resorting to brute force? This question may sound strange, so let me provide a use-case: User signs up to a site with their e-mail address Server sends that e-mail address a confirmation URL (for example: https://my.app.com/confirmEmailAddress/bill%40yahoo.com) Attacker can guess the confirmation URL and therefore can sign up with someone else's e-mail address, and 'confirm' it without ever having to sign in to that person's e-mail account and see the confirmation URL. This is a problem. Instead of sending the e-mail address plain text in the URL, we'll send it encrypted by a secret passphrase. (I know the attacker could still intercept the e-mail sent by the server, since e-mail are plain text, but bear with me here.) If an attacker then signs up with multiple free e-mail accounts and sees multiple URLs, each with the corresponding encrypted e-mail address, could the attacker more easily determine the passphrase used for encryption? Alternative Solution I could instead send a random number or one-way hash of their e-mail address (plus random salt). This eliminates storing the secret passphrase, but it means I need to store that random number/hash in the database. The original approach above does not require storage in the database. I'm leaning towards the the one-way-hash-stored-in-the-db, but I still would like to know the answer: does having multiple unencrypted e-mail addresses and their encrypted counterparts make it easier to determine the passphrase used?

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• Embedded non-relational (nosql) data store

  - by Igor Brejc

  I'm thinking about using/implementing some kind of an embedded key-value (or document) store for my Windows desktop application. I want to be able to store various types of data (GPS tracks would be one example) and of course be able to query this data. The amount of data would be such that it couldn't all be loaded into memory at the same time. I'm thinking about using sqlite as a storage engine for a key-value store, something like y-serial, but written in .NET. I've also read about FriendFeed's usage of MySQL to store schema-less data, which is a good pointer on how to use RDBMS for non-relational data. sqlite seems to be a good option because of its simplicity, portability and library size. My question is whether there are any other options for an embedded non-relational store? It doesn't need to be distributable and it doesn't have to support transactions, but it does have to be accessible from .NET and it should have a small download size. UPDATE: I've found an article titled SQLite as a Key-Value Database which compares sqlite with Berkeley DB, which is an embedded key-value store library.

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