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  • Application Errors vs User Errors in PHP

    - by CogitoErgoSum
    So after much debate back and forth, I've come up with what I think may be a valid plan to handle Application/System errors vs User Errors (I.e. Validation Issues, Permission Issues etc). Application/System Errors will be handled using a custom error handler (via set_error_handler()). Depending on the severity of the error, the user may be redirected to a generic error page (I.e. Fatal Error), or the error may simply be silently logged (i.e E_WARNING). These errors are ones most likely caused by issues outside the users control (Missing file, Bad logic, etc). The second set of errors would be User Generated ones. These are the ones may not automatically trigger an error but would be considered one. In these cases i"ve decided to use the trigger_error() function and typically throw a waning or notice which would be logged silently by the error handler. After that it would be up to the developer to then redirect the user to another page or display some sort of more meaningful message to the user. This way an error of any type is always logged, but user errors still allow the developer freedom to handle it in their own ways. I.e. Redirect them back to their form with it fully repopulated and a message of what went wrong. Does anyone see anything wrong with this, or have a more intuitive way? My approach to error handling is typically everyone has their own ways but there must be a way instituted.

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  • Implicit conversion : const reference vs non-const reference vs non-reference

    - by Nawaz
    Consider this code, struct A {}; struct B { B(const A&) {} }; void f(B) { cout << "f()"<<endl; } void g(A &a) { cout << "g()" <<endl; f(a); //a is implicitly converted into B. } int main() { A a; g(a); } This compiles fine, runs fine. But if I change f(B) to f(B&), it doesn't compile. If I write f(const B&), it again compiles fine, runs fine. Why is the reason and rationale? Summary: void f(B); //okay void f(B&); //error void f(const B&); //okay I would like to hear reasons, rationale and reference(s) from the language specification, for each of these cases. Of course, the function signatures themselves are not incorrect. Rather A implicitly converts into B and const B&, but not into B&, and that causes the compilation error.

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  • Are endless loops in bad form?

    - by rlbond
    So I have some C++ code for back-tracking nodes in a BFS algorithm. It looks a little like this: typedef std::map<int> MapType; bool IsValuePresent(const MapType& myMap, int beginVal, int searchVal) { int current_val = beginVal; while (true) { if (current_val == searchVal) return true; MapType::iterator it = myMap.find(current_val); assert(current_val != myMap.end()); if (current_val == it->second) // end of the line return false; current_val = it->second; } } However, the while (true) seems... suspicious to me. I know this code works, and logically I know it should work. However, I can't shake the feeling that there should be some condition in the while, but really the only possible one is to use a bool variable just to say if it's done. Should I stop worrying? Or is this really bad form. EDIT: Thanks to all for noticing that there is a way to get around this. However, I would still like to know if there are other valid cases.

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  • asp.net Impersonate User for network resource access

    - by lonelycoder
    code: System.Security.Principal.WindowsImpersonationContext impersonationContext; impersonationContext = ((System.Security.Principal.WindowsIdentity)User.Identity).Impersonate(); //access network resources. impersonationContext.Undo(); web.config: <authentication mode="Windows"> </authentication> <identity impersonate="true" userName="user" password="password"></identity> As clear from web.config file, the app runs in an impersonated mode. I need to impersonate temporarily on top of that to access a network resource. I do that as shown above. This works fine on server if I browse to the website on the local IE installed on the server but when I access the app from my PC or any other PC, I get a access denied. Btw, this is all within an enterprise domain environment. so IE in both cases is passing a valid authenticated token. Any ideas what is going on. thanks.

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  • Why are floating point values so prolific?

    - by Kibbee
    So, title says it all. Why are floating point values so prolific in computer programming. Due to problems like rounding errors, and not being able to even accurately represent numbers such as 0.1, I really can't see how they got as far as they did. I understand that the computation is faster with floating point numbers, however, I can think of only a few cases that they actually the right data type would be using. If you sat back and think about every time you used a floating point value, how many times did you say, well, some error would be ok, as long as the result was a few microseconds faster. It really makes me think because Jeff was talking about NP completeness, and how heuristics give an answer that is kind of right. And well, computers shouldn't do that. They should give you the answer that is correct. Yet we see floating point values used in many applications where they are completely not valid. What really bugs me, isn't that floating point exists, but that in many languages, there isn't even a viable alternative, non-floating point, decimal value. A lot of programmers when doing financial applications have to fall back to storing the number of cents in an integer field. Which brings with it all kinds of other problems. Why do floats continue to be so prolific, even though they can't represent the real answer, and we expect computers to be accurate? [EDIT] Just to clarify, I was talking about Base 2 floating points, and not base 10 floating points. .Net offers the Decimal data type, which is a base 10 floating point value which offers a much better representation of the numbers we deal with on a daily basis in most computer programs. I find it hard to believe that even modern languages like Java don't support base 10 floating point values, unless you want to move into the realm of things like BigDecimal, which isn't really the right answer either in a lot of situations.

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  • ClassCastException When Calling an EJB that Exists on Same Server

    - by aaronvargas
    I have 2 ejbs. Ejb-A that calls Ejb-B. They are not in the same Ear. For portability Ejb-B may or may not exist on the same server. (There is an external property file that has the provider URLs of Ejb-B. I have no control over this.) Example Code: in Ejb-A EjbBDelegate delegateB = EjbBDelegateHelper.getRemoteDelegate(); // lookup from list of URLs from props... BookOfMagic bom = delegateB.getSomethingInteresting(); Use Cases/Outcomes: When Ejb-B DOES NOT EXIST on the same server as Ejb-A, everything works correctly. (it round-robbins through the URLs) When Ejb-B DOES EXIST on the same server, and Ejb-A happens to call Ejb-B on the same server, everything works correctly. When Ejb-B DOES EXIST on the same server, and Ejb-A calls Ejb-B on a different server, I get: javax.ejb.EJBException: nested exception is: java.lang.ClassCastException: $Proxy126 java.lang.ClassCastException: $Proxy126 NOTE (not normal use case but may help): When Ejb-B DOES EXIST on the same server, and this server is NOT listed in the provider URLs for Ejb-B, and Ejb-A calls Ejb-B on a different server, I get the same Exception as above. I'm using Weblogic 10.0, Java 5, EJB3 Basically, if Ejb-B Exists on the server, it must be called ONLY on that server. Which leads me to believe that the class is getting loaded by a local classloader (on deployment?), then when called remotely, a different classloader is loading it. (causing the Exception) But it should work, as it should be Serialized into the destination classloader... What am I doing wrong?? Also, when reproducing this locally, Ejb-A would favor the Ejb-B on the same server, so it was difficult to reproduce. But this wasn't the case on other machines.

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  • Hidden features of Perl?

    - by Adam Bellaire
    What are some really useful but esoteric language features in Perl that you've actually been able to employ to do useful work? Guidelines: Try to limit answers to the Perl core and not CPAN Please give an example and a short description Hidden Features also found in other languages' Hidden Features: (These are all from Corion's answer) C# Duff's Device Portability and Standardness Quotes for whitespace delimited lists and strings Aliasable namespaces Java Static Initalizers JavaScript Functions are First Class citizens Block scope and closure Calling methods and accessors indirectly through a variable Ruby Defining methods through code PHP Pervasive online documentation Magic methods Symbolic references Python One line value swapping Ability to replace even core functions with your own functionality Other Hidden Features: Operators: The bool quasi-operator The flip-flop operator Also used for list construction The ++ and unary - operators work on strings The repetition operator The spaceship operator The || operator (and // operator) to select from a set of choices The diamond operator Special cases of the m// operator The tilde-tilde "operator" Quoting constructs: The qw operator Letters can be used as quote delimiters in q{}-like constructs Quoting mechanisms Syntax and Names: There can be a space after a sigil You can give subs numeric names with symbolic references Legal trailing commas Grouped Integer Literals hash slices Populating keys of a hash from an array Modules, Pragmas, and command-line options: use strict and use warnings Taint checking Esoteric use of -n and -p CPAN overload::constant IO::Handle module Safe compartments Attributes Variables: Autovivification The $[ variable tie Dynamic Scoping Variable swapping with a single statement Loops and flow control: Magic goto for on a single variable continue clause Desperation mode Regular expressions: The \G anchor (?{}) and '(??{})` in regexes Other features: The debugger Special code blocks such as BEGIN, CHECK, and END The DATA block New Block Operations Source Filters Signal Hooks map (twice) Wrapping built-in functions The eof function The dbmopen function Turning warnings into errors Other tricks, and meta-answers: cat files, decompressing gzips if needed Perl Tips See Also: Hidden features of C Hidden features of C# Hidden features of C++ Hidden features of Java Hidden features of JavaScript Hidden features of Ruby Hidden features of PHP Hidden features of Python

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  • Formatting and pretty printing dates with jquery

    - by Tauren
    I need to display dates in a couple different ways in an app built with jquery. In some situations, I need the typical "yyyy-mm-dd hh:mma" type of formatting, with all of it's different permutations. In other cases, I need to show dates "pretty printed" similar to how StackOverflow does them: 5 seconds ago 12 minutes ago 3 hours ago yesterday 2 days ago My application already uses JQuery UI DatePicker which includes a formatDate() function, but as far as I can tell, there is no way to use it outside of the datepicker. I want to format dates that aren't associated with a datepicker. Is it possible to do this using DatePicker? The DateJS library can parse dates like "12 minutes ago", but as far as I can tell, it cannot take a Date object and format strings like this. It can format the typical "yyyy-mm-dd" types of formats. This library seems pretty heavy as well. John Resig's Pretty Dates looks like it can provide the pretty printing ("2 hours ago"), but it doesn't do the standard formatting. Is there not a single plugin that can do all of this? Is there a way to leverage the DatePicker code so I don't have to load multiple codebases that do the same things?

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  • Mixing NIO with IO

    - by Steffen Heil
    Hi Usually you have a single bound tcp port and several connections on these. At least there are usually more connections as bound ports. My case is different: I want to bind a lot of ports and usually have no (or at least very few) connections. So I want to use NIO to accept the incoming connections. However, I need to pass the accepted connections to the existing jsch ssh library. That requires IO sockets instead of NIO sockets, it spawns one (or two) thread(s) per connection. But that's fine for me. Now, I thought that the following lines would deliver the very same result: Socket a = serverSocketChannel.accept().socket(); Socket b = serverSocketChannel.socket().accep(); SocketChannel channel = serverSocketChannel.accpet(); channel.configureBlocking( true ); Socket c = channel.socket(); Socket d = serverSocket.accept(); However the getInputStream() and getOutputStream() functions of the returned sockets seem to work different. Only if the socket was accepted using the last call, jsch can work with it. In the first three cases, it fails (and I am sorry: I don't know why). So is there a way to convert such a socket? Regards, Steffen

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  • When does a PHP <5.3.0 daemon script receive signals?

    - by MidnightLightning
    I've got a PHP script in the works that is a job worker; its main task is to check a database table for new jobs, and if there are any, to act on them. But jobs will be coming in in bursts, with long gaps in between, so I devised a sleep cycle like: while(true) { if ($jobs = get_new_jobs()) { // Act upon the jobs } else { // No new jobs now sleep(30); } } Good, but in some cases that means there might be a 30 second lag before a new job is acted upon. Since this is a daemon script, I figured I'd try the pcntl_signal hook to catch a SIGUSR1 signal to nudge the script to wake up, like: $_isAwake = true; function user_sig($signo) { global $_isAwake; daemon_log("Caught SIGUSR1"); $_isAwake = true; } pcntl_signal(SIGUSR1, 'user_sig'); while(true) { if ($jobs = get_new_jobs()) { // Act upon the jobs } else { // No new jobs now daemon_log("No new jobs, sleeping..."); $_isAwake = false; $ts = time(); while(time() < $ts+30) { sleep(1); if ($_isAwake) break; // Did a signal happen while we were sleeping? If so, stop sleeping } $_isAwake = true; } } I broke the sleep(30) up into smaller sleep bits, in case a signal doesn't interrupt a sleep() command, thinking that this would cause at most a one-second delay, but in the log file, I'm seeing that the SIGUSR1 isn't being caught until after the full 30 seconds has passed (and maybe the outer while loop resets). I found the pcntl_signal_dispatch command, but that's only for PHP 5.3 and higher. If I were using that version, I could stick a call to that command before the if ($_isAwake) call, but as it currently stands I'm on 5.2.13. On what sort of situations is the signals queue interpreted in PHP versions without the means to explicitly call the queue parsing? Could I put in some other useless command in that sleep loop that would trigger a signal queue parse within there?

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  • How to deploy a WPF 4 Full Trust XBAP an on intranet?

    - by sparks
    I'm having trouble running a full trust WPF 4 XBAP (browser application), created with Visual Studio 2010, from my intranet. I do not get a ClickOnce elevation prompt, as described in ScottGu's post on WPF 4: Full Trust XBAP Deployment Starting in WPF 4, the ClickOnce elevation prompt is also enabled for XAML Browser Applications (XBAPs) in Intranet and Trusted Zones, making it easier to deploy full-trust XBAPs. For XBAPs that require security permissions greater than the minimum code access security (CAS) permission grantset of the Intranet and Trusted Zones, the user will be able to click 'Run' on the ClickOnce elevation prompt when they navigate to the XBAP to allow the XBAP to run with the requested permissions. Instead, I get the "Trust Not Granted" message. I'm running the application in two ways; in both cases, I get the "Trust Not Granted" message. First, I'm launching the application by double-clicking on the xbap file from my NAS on the local network. Secondly, I'm also trying to launch the application when it is hosted on a website via IIS from the same machine. Are both of these scenarios considered to be run from an "intranet?" Or does "intranet" mean some in particular here? Or am I doing something completely wrong? Of note, I am able to launch the application without problem when I simply double-click the xbap from my local computer. The xbap in question was created specifically to test the ClickOnce elevation prompt. It was created with Visual Studio 2010 as a WPF Browser Application. The only change I made was to change this to a full trust application (My Project Security tab This is a full trust application). In the publish wizard, I am choosing the following: Where do you want to publish the application? - I chose to publish to a local directory How will user install the application? - I chose "From a CD-ROM or DVD-ROM" Will the application be available offline - All choices were grayed out

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  • Command-Line Parsing API from TestAPI library - Type-Safe Commands how to

    - by MicMit
    Library at http://testapi.codeplex.com/ Excerpt of usage from http://blogs.msdn.com/ivo_manolov/archive/2008/12/17/9230331.aspx A third common approach is forming strongly-typed commands from the command-line parameters. This is common for cases when the command-line looks as follows: some-exe COMMAND parameters-to-the-command The parsing in this case is a little bit more involved: Create one class for every supported command, which derives from the Command abstract base class and implements an expected Execute method. Pass an expected command along with the command-line arguments to CommandLineParser.ParseCommand – the method will return a strongly-typed Command instance that can be Execute()-d. // EXAMPLE #3: // Sample for parsing the following command-line: // Test.exe run /runId=10 /verbose // In this particular case we have an actual command on the command-line (“run”), which we want to effectively de-serialize and execute. public class RunCommand : Command { bool? Verbose { get; set; } int? RunId { get; set; } public override void Execute() { // Implement your "run" execution logic here. } } Command c = new RunCommand(); CommandLineParser.ParseArguments(c, args); c.Execute(); ============================ I don't get if we instantiate specific class before parsing arguments , what's the point of command line argument "run" which is very first one. I thought the idea was to instantiate and execute command/class based on a command line parameter ( "run" parameter becomes instance RunCommand class, "walk" becomes WalkCommand class and so on ). Can it be done with the latest version ?

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  • Taking "do the simplest thing that could possible work" too far in TDD: testing for a file-name kno

    - by Support - multilanguage SO
    For TDD you have to Create a test that fail Do the simplest thing that could possible work to pass the test Add more variants of the test and repeat Refactor when a pattern emerge With this approach you're supposing to cover all the cases ( that comes to my mind at least) but I'm wonder if am I being too strict here and if it is possible to "think ahead" some scenarios instead of simple discover them. For instance, I'm processing a file and if it doesn't conform to a certain format I am to throw an InvalidFormatException So my first test was: @Test void testFormat(){ // empty doesn't do anything nor throw anything processor.validate("empty.txt"); try { processor.validate("invalid.txt"); assert false: "Should have thrown InvalidFormatException"; } catch( InvalidFormatException ife ) { assert "Invalid format".equals( ife.getMessage() ); } } I run it and it fails because it doesn't throw an exception. So the next thing that comes to my mind is: "Do the simplest thing that could possible work", so I : public void validate( String fileName ) throws InvalidFormatException { if(fileName.equals("invalid.txt") { throw new InvalidFormatException("Invalid format"); } } Doh!! ( although the real code is a bit more complicated, I found my self doing something like this several times ) I know that I have to eventually add another file name and other test that would make this approach impractical and that would force me to refactor to something that makes sense ( which if I understood correctly is the point of TDD, to discover the patterns the usage unveils ) but: Q: am I taking too literal the "Do the simplest thing..." stuff?

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  • overriding enumeration base type using pragma or code change

    - by vprajan
    Problem: I am using a big C/C++ code base which works on gcc & visual studio compilers where enum base type is by default 32-bit(integer type). This code also has lots of inline + embedded assembly which treats enum as integer type and enum data is used as 32-bit flags in many cases. When compiled this code with realview ARM RVCT 2.2 compiler, we started getting many issues since realview compiler decides enum base type automatically based on the value an enum is set to. http://www.keil.com/support/man/docs/armccref/armccref_Babjddhe.htm For example, Consider the below enum, enum Scale { TimesOne, //0 TimesTwo, //1 TimesFour, //2 TimesEight, //3 }; This enum is used as a 32-bit flag. but compiler optimizes it to unsigned char type for this enum. Using --enum_is_int compiler option is not a good solution for our case, since it converts all the enum's to 32-bit which will break interaction with any external code compiled without --enum_is_int. This is warning i found in RVCT compilers & Library guide, The --enum_is_int option is not recommended for general use and is not required for ISO-compatible source. Code compiled with this option is not compliant with the ABI for the ARM Architecture (base standard) [BSABI], and incorrect use might result in a failure at runtime. This option is not supported by the C++ libraries. Question How to convert all enum's base type (by hand-coded changes) to use 32-bit without affecting value ordering? enum Scale { TimesOne=0x00000000, TimesTwo, // 0x00000001 TimesFour, // 0x00000002 TimesEight, //0x00000003 }; I tried the above change. But compiler optimizes this also for our bad luck. :( There is some syntax in .NET like enum Scale: int Is this a ISO C++ standard and ARM compiler lacks it? There is no #pragma to control this enum in ARM RVCT 2.2 compiler. Is there any hidden pragma available ?

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  • Could CouchDB benefit significantly from the use of BERT instead of JSON?

    - by Victor Rodrigues
    I appreciate a lot CouchDB attempt to use universal web formats in everything it does: RESTFUL HTTP methods in every interaction, JSON objects, javascript code to customize database and documents. CouchDB seems to scale pretty well, but the individual cost to make a request usually makes 'relational' people afraid of. Many small business applications should deal with only one machine and that's all. In this case the scalability talk doesn't say too much, we need more performance per request, or people will not use it. BERT (Binary ERlang Term http://bert-rpc.org/ ) has proven to be a faster and lighter format than JSON and it is native for Erlang, the language in which CouchDB is written. Could we benefit from that, using BERT documents instead of JSON ones? I'm not saying just for retrieving in views, but for everything CouchDB does, including syncing. And, as a consequence of it, use Erlang functions instead of javascript ones. This would modify some original CouchDB principles, because today it is very web oriented. Considering I imagine few people would make their database API public and usually its data is accessed by the users through an application, it would be a good deal to have the ability to configure CouchDB for working faster. HTTP+JSON calls could still be handled by CouchDB, considering an extra cost in these cases because of parsing.

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  • AutoMapper How To Map Object A To Object B Differently Depending On Context

    - by IanT8
    Calling all AutoMapper gurus! I'd like to be able to map object A to object B differently depending on context at runtime. In particular, I'd like to ignore certain properties in one mapping case, and have all properties mapped in another case. What I'm experiencing is that Mapper.CreateMap can be called successfully in the different mapping cases however, once CreateMap is called, the map for a particular pair of types is set and is not subsequently changed by succeeding CreateMap calls which might describe the mapping differently. I found a blog post which advocates Mapper.Reset() to get round the problem, however, the static nature of the Mapper class means that it is only a matter of time before a collision and crash occur. Is there a way to do this? What I think I need is to call Mapper.CreateMap once per appdomain, and later, be able to call Mapper.Map with hints about which properties should be included / excluded. Right now, I'm thinking about changing the source code by writing a non-static mapping class that holds the mapping config instance based. Poor performance, but thread safe. What are my options. What can be done? Automapper seems so promising.

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  • WPF UI Automation - AutomationElement.FindFirst fails when there are lots of elements

    - by Orion Edwards
    We've got some automated UI tests for our WPF app (.NET 4); these test use the UI Automation API's. We call AutomationElement.FindFirst to find a target element, and then interact with it. Example (pseudocode): var nameEquals = new PropertyCondition(AutomationElement.NameProperty, "OurAppWindow"); var appWindow = DesktopWindow.FindFirst(TreeScope.Children, nameEquals); // this succeeds var idEquals = new PropertyCondition(AutomationElement.AutomationIdProperty, "ControlId"); var someItem = appWindow.FindFirst(TreeScope.Descendants, idEquals); // this suceeds sometimes, and fails sometimes! The problem is, the appWindow.FindFirst will sometimes fail and return null, even when the element is present. I've written a helper function which walks the UI automation tree manually and prints it out, and the element with the correct ID is present in all cases. It seems to be related to how many other items are also being displayed in the window. If there are no other items then it always succeeds, but when there are many other complex UI elements being displayed alongside it, then the find fails. I can't find any documented element limit mentioned for any of the automation API's - is there some way around this? I'm thinking I might have to write my own implemententation of FindFirst which does the tree walk manually itself... As far as I can tell this should work, because my tree-printer utility function does exactly that, and it's ok, but it seems like this would be unnecessary and slow :-( Any help would be greatly appreciated

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  • ClickOnce Deployment Error - Access to the Path is Denied

    - by michael.lukatchik
    I have a WPF app that I'm deploying to a network path using ClickOnce deployment. After the app is deployed to a network location, I use the ClickOnce html page to launch the installation process. I am successfully able to download and install the app. However, my users are not able to download and install the app. When a user navigates to the ClickOnce html page and clicks to begin the installation process, the following error message is received: ERROR SUMMARY Below is a summary of the errors, details of these errors are listed later in the log. * Activation of http://software.mycompany.com/myapp/myapp.application resulted in exception. Following failure messages were detected: + Downloading file://dev/webs/software/myapp/myapp.application did not succeed. * [4/5/2010 1:56:59 PM] System.Deployment.Application.DeploymentDownloadException (Unknown subtype) - Downloading file://dev/Webs/software/myapp/myapp.application did not succeed. All signs point to this being a security issue. So, I've done the following: Ensured that "Everyone" had read access to the files that were being deployed as part of my project Ensured that "Everyone" had read access to the network location where the app was deployed (//dev/webs/software/myapp) Ensured that "Everyone" had read access to the IIS path where the ClickOnce html page is located In each of these cases, I've made no progress in getting the app to successfully deploy via ClickOnce. Again, the odd thing is that I am able to successfully walk through the process of downloading and installing the app. It's my users, though, that need the ability to download and install the app. I've looked extensively on the web for answers, but there hasn't been much. I'd like to resolve the issue without "re-installing" or "rigging" anything. I need a solid answer. Thank you all for your input!! Mike

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  • Using ThreadPool.QueueUserWorkItem in ASP.NET in a high traffic scenario

    - by Michael Hart
    I've always been under the impression that using the ThreadPool for (let's say non-critical) short-lived background tasks was considered best practice, even in ASP.NET, but then I came across this article that seems to suggest otherwise - the argument being that you should leave the ThreadPool to deal with ASP.NET related requests. So here's how I've been doing small asynchronous tasks so far: ThreadPool.QueueUserWorkItem(s => PostLog(logEvent)) And the article is suggesting instead to create a thread explicitly, similar to: new Thread(() => PostLog(logEvent)){ IsBackground = true }.Start() The first method has the advantage of being managed and bounded, but there's the potential (if the article is correct) that the background tasks are then vying for threads with ASP.NET request-handlers. The second method frees up the ThreadPool, but at the cost of being unbounded and thus potentially using up too many resources. So my question is, is the advice in the article correct? If your site was getting so much traffic that your ThreadPool was getting full, then is it better to go out-of-band, or would a full ThreadPool imply that you're getting to the limit of your resources anyway, in which case you shouldn't be trying to start your own threads? Clarification: I'm just asking in the scope of small non-critical asynchronous tasks (eg, remote logging), not expensive work items that would require a separate process (in these cases I agree you'll need a more robust solution).

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  • Non-deprecated code for detecting whether a SharePoint User has a specific Permission Level

    - by ccomet
    In our application, we have some forms which need to show some data specifically if the current user has a specific permission level. These users belong to an SPGroup which includes users who should not see this data, so in this particular case I cannot filter based off of group membership. My current solution has been to use web.CurrentUser.Roles and use a simple check on whether it contains a permission level of the correct name. Roles is of the deprecated SPRole class, so I am bombarded with warning messages despite the fact it technically works. It suggests that I use SPRoleAssignment or SPRoleDefinition (the recommendation seems arbitrary since some lines recommend one while others recommend the other even though it is being used for the same thing). However, I cannot seem to find any method to directly retrieve an SPRoleAssignment or SPRoleDefinition object from an SPUser or SPPrincipal object, nor can I retrieve either object corresponding specifically to the current user of the SPWeb object. How can I update these methods to use non-deprecated code? I've found other cases of determining user permissions, but I haven't found one that will work from a starting point of the current web or the current user. It's not urgent, but it certainly is helpful to avoid having to sift through all of those warnings just to reach the more important warnings.

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  • NPTL Default Stack Size Problem

    - by eyazici
    Hello, I am developing a multithread modular application using C programming language and NPTL 2.6. For each plugin, a POSIX thread is created. The problem is each thread has its own stack area, since default stack size depends on user's choice, this may results in huge memory consumption in some cases. To prevent unnecessary memory usage I used something similar to this to change stack size before creating each thread: pthread_attr_t attr; pthread_attr_init (&attr); pthread_attr_getstacksize(&attr, &st1); if(pthread_attr_setstacksize (&attr, MODULE_THREAD_SIZE) != 0) perror("Stack ERR"); pthread_attr_getstacksize(&attr, &st2); printf("OLD:%d, NEW:%d - MIN: %d\n", st1, st2, PTHREAD_STACK_MIN); pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); /* "this" is static data structure that stores plugin related data */ pthread_create(&this->runner, &attr, (void *)(void *)this->run, NULL); EDIT I: pthread_create() section added. This did not work work as I expected, the stack size reported by pthread_attr_getstacksize() is changed but total memory usage of the application (from ps/top/pmap output) did not changed: OLD:10485760, NEW:65536 - MIN: 16384 When I use ulimit -s MY_STACK_SIZE_LIMIT before starting application I achieve the expected result. My questions are: 1-) Is there any portable(between UNIX variants) way to change (default)thread stack size after starting application(before creating thread of course)? 2-) Is it possible to use same stack area for every thread? 3-) Is it possible completely disable stack for threads without much pain?

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  • Which key:value store to use with Python?

    - by Kurt
    So I'm looking at various key:value (where value is either strictly a single value or possibly an object) stores for use with Python, and have found a few promising ones. I have no specific requirement as of yet because I am in the evaluation phase. I'm looking for what's good, what's bad, what are the corner cases these things handle well or don't, etc. I'm sure some of you have already tried them out so I'd love to hear your findings/problems/etc. on the various key:value stores with Python. I'm looking primarily at: memcached - http://www.danga.com/memcached/ python clients: http://pypi.python.org/pypi/python-memcached/1.40 http://www.tummy.com/Community/software/python-memcached/ CouchDB - http://couchdb.apache.org/ python clients: http://code.google.com/p/couchdb-python/ Tokyo Tyrant - http://1978th.net/tokyotyrant/ python clients: http://code.google.com/p/pytyrant/ Lightcloud - http://opensource.plurk.com/LightCloud/ Based on Tokyo Tyrant, written in Python Redis - http://code.google.com/p/redis/ python clients: http://pypi.python.org/pypi/txredis/0.1.1 MemcacheDB - http://memcachedb.org/ So I started benchmarking (simply inserting keys and reading them) using a simple count to generate numeric keys and a value of "A short string of text": memcached: CentOS 5.3/python-2.4.3-24.el5_3.6, libevent 1.4.12-stable, memcached 1.4.2 with default settings, 1 gig memory, 14,000 inserts per second, 16,000 seconds to read. No real optimization, nice. memcachedb claims on the order of 17,000 to 23,000 inserts per second, 44,000 to 64,000 reads per second. I'm also wondering how the others stack up speed wise.

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  • Beginner question - Loop invariants (Specifically Ch.3 of "Accelerated C++")

    - by Owen
    Hi - as I said, a complete beginner question here. I'm currently working my way through "Accelerated C++" and just came across this in chapter 3: // invariant: // we have read count grades so far, and // sum is the sum of the first count grades while (cin >> x) { ++count; sum += x; } The authors follow this by explaining that the invariant needs special attention paid to it because when the input is read into the variable x, we will have read count+1 grades and thus the invariant will be untrue. Similarly, when we have incremented the counter, the variable sum will no longer be the sum of the last count grades (in case you hadn't guessed, it's the traditional program for calculating student marks). What I don't understand is why this matters. Surely for just about any other loop, a similar statement would be true? For example, here is the book's first while loop (the output is filled in later): // invariant: we have written r rows so far while (r != rows) { // write a row of output std::cout << std::endl; ++r; } Once we have written the appropriate row of output, surely the invariant is false until we have incremented r, just as in the other example? It's probably something really obvious, anyone could enlighten me as to what makes these two cases different, that'd be great - and thanks in advance for taking the time to answer such a complete novice question. Owen

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  • Show models.ManyToManyField as inline, with the same form as models.ForeignKey inline

    - by Kristian
    I have a model similar to the following (simplified): models.py class Sample(models.Model): name=models.CharField(max_length=200) class Action(models.Model): samples=models.ManyToManyField(Sample) title=models.CharField(max_length=200) description=models.TextField() Now, if Action.samples would have been a ForeignKey instead of a ManyToManyField, when I display Action as a TabularInline in Sample in the Django Admin, I would get a number of rows, each containing a nice form to edit or add another Action. However; when I display the above as an inline using the following: class ActionInline(admin.TabularInline): model=Action.samples.through I get a select box listing all available actions, and not a nifty form to create a new Action. My question is really: How do I display the ManyToMany relation as an inline with a form to input information as described? In principle it should be possible since, from the Sample's point of view, the situation is identical in both cases; Each Sample has a list of Actions regardless if the relation is a ForeignKey or a ManyToManyRelation. Also; Through the Sample admin page, I never want to choose from existing Actions, only create new or edit old ones.

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  • Extending Python and Objective-C

    - by chpwn
    I'm a fan of clean code. I like my languages to be able to express what I'm trying to do, but I like the syntax to mirror that too. For example, I work on a lot of programs in Objective-C for jailbroken iPhones, which patch other code using the method_setImplementation() function of the runtime. Or, in PyObjC, I have to use the syntax UIView.initWithFrame_(), which is also pretty awful and unreadable with the way the method names are structured. In both cases, the language does not support this in syntax. I've found three basic ways that this is done: Insane macros. Take a look at this "CaptainHook", it does what I'm looking for in a usable way, but it isn't quite clean and is a major hack. There's also "Logos", which implements a very nice syntax, but is written in Perl parsing my code with a ton of regular expressions. This scares me. I like the idea of adding a %hook ClassName, but not by using regular expressions to parse C or Objective-C. Finally, there is Cycript. This is an extension to JavaScript which interfaces with the Objective-C runtime and allows you to use Objective-C style code in your JavaScript, and inject that into other processes. This is likely the cleanest as it actually uses a parser for the JavaScript, but I'm not a huge fan of that language in general. Should, and how should, I create an extension to Python and Objective-C to allow me to do this? Is it worth writing a parser for my language to transform the syntax into something nicer, if it is only in a very specialized niche like this? Should I just live with the horrible syntax of the default Objective-C hooking or PyObjC?

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