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  • Authentication and Security in my website - need advice please.

    - by Ichirichi
    Hi, I am using database with a list of username/passwords, and a simple web form that allows for users to enter their username/password. When they submit the page, I simply do a stored procedure check to authenticate. If they are authorised, then their user details (e.g. username, dob, address, company address, other important info) are stored in a custom User object and then in a session. This custom User object that I created is used throughout the web application, and also in a sub-site (session sharing). My question/problems are: Is my method of authentication the correct way to do things? I find users complaining that their session have expired although they "were not idle", possibly due the app pool recycling? They type large amounts of text and find that their session had expired and thus lose all the text typed in. I am uncertain whether the session does really reset sporadically but will Forms Authentication using cookies/cookiless resolve the issue? Alternatively should I build and store the User Object in a session, cookie or something else instead in order to be more "correct" and avoid cases like in point #2. If I go down the Forms Authentication route, I believe I cannot store my custom User object in a Forms Authentication cookie so does it mean I would store the UserID and then recreate the user object on every page? Would this not be a huge increase on the server load? Advice and answers much appreciated. L

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  • When to use basic types (Integer, String), and when to write a new class?

    - by belgarat
    Stackoverflow users: A lot of things can be represented in programs by using the basic types, or we can create a new class for it. Example: A social security number can be a number, string or its own object. (Other common examples: Phone numbers, names, zip codes, user id, order id and other id's.) My question is: When should the basic types be used, and when should we write ourselves a new class? I see that when you need to add behavior, you'll want to create a class (example, social security number parsing, validation, formatting, etc). But is this the only criteria? I have come across cases where many of these things are represented as java Integers and/or Strings. We loose the benefit of type-checking, and I have often seen bugs caused by parameters being mixed in calls to function(Intever, Integer, Integer, Integer). On the other hand, some programmers are opposed to over-designing by creating classes for "eveything". Obviously, the answer is "it depends". But, what do you think, and what do you normally do?

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  • .NET: bool vs enum as a method parameter

    - by Julien Lebosquain
    Each time I'm writing a method that takes a boolean parameter representing an option, I find myself thinking: "should I replace this by an enum which would make reading the method calls much easier?". Consider the following with an object that takes a parameter telling whether the implementation should use its thread-safe version or not (I'm not asking here if this way of doing this is good design or not, only the use of the boolean): public void CreateSomeObject(bool makeThreadSafe); CreateSomeObject(true); When the call is next to the declaration the purpose of the parameter seems of course obvious. When it's in some third party library you barely know, it's harder to immediately see what the code does, compared to: public enum CreationOptions { None, MakeThreadSafe } public void CreateSomeObject(CreationOptions options); CreateSomeObject(CreationOptions.MakeThreadSafe); which describes the intent far better. Things get worse when there's two boolean parameters representing options. See what happened to ObjectContext.SaveChanges(bool) between Framework 3.5 and 4.0. It has been obsoleted because a second option has been introduced and the whole thing has been converted to an enum. While it seems obvious to use an enumeration when there's three elements or more, what's your opinion and experiences about using an enum instead a boolean in these specific cases?

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  • Refactoring a complicated if-condition

    - by kumar kasimala
    Hi all, Can anyone suggest best way to avoid most if conditions? I have below code, I want avoid most of cases if conditions, how to do it ? any solution is great help; if (adjustment.adjustmentAccount.isIncrease) { if (adjustment.increaseVATLine) { if (adjustment.vatItem.isSalesType) { entry2.setDebit(adjustment.total); entry2.setCredit(0d); } else { entry2.setCredit(adjustment.total); entry2.setDebit(0d); } } else { if (adjustment.vatItem.isSalesType) { entry2.setCredit(adjustment.total); entry2.setDebit(0d); } else { entry2.setDebit(adjustment.total); entry2.setCredit(0d); } } } else { if (adjustment.increaseVATLine) { if (adjustment.vatItem.isSalesType) { entry2.setCredit(adjustment.total); entry2.setDebit(0d); } else { entry2.setDebit(adjustment.total); entry2.setCredit(0d); } } else { if (adjustment.vatItem.isSalesType) { entry2.setDebit(adjustment.total); entry2.setCredit(0d); } else { entry2.setCredit(adjustment.total); entry2.setDebit(0d); } } }

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  • Does this code depend on string interning to work?

    - by Nick Gotch
    I'm creating a key for a dictionary which is a structure of two strings. When I test this method in a console app, it works, but I'm not sure if the only reason it works is because the strings are being interned and therefore have the same references. Foo foo1 = new Foo(); Foo foo2 = new Foo(); foo1.Key1 = "abc"; foo2.Key1 = "abc"; foo1.Key2 = "def"; foo2.Key2 = "def"; Dictionary<Foo, string> bar = new Dictionary<Foo, string>(); bar.Add(foo1, "found"); if(bar.ContainsKey(foo2)) System.Console.WriteLine("This works."); else System.Console.WriteLine("Does not work"); The struct is simply: public struct Foo { public string Key1; public string Key2; } Are there any cases which would cause this to fail or am I good to rely on this as a unique key?

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  • Looking for out-of-place directories in an SVN working copy?

    - by jthg
    An annoyance that I sometimes come across with SVN is the working copy getting corrupted by one of the .svn folders getting moved from its original location. It doesn't happen often if you're careful and use the proper tools for all moves and renames, but it still somehow happens from time to time. First, does anyone know if there's a good way to catch the problem before a commit is even done? Cruise control usually catches the problem, but there are plenty of cases it wouldn't catch. Second, is there a quick and easy way to check for out-of-place .svn folder if I suspect that there is one? I can definitely do it manually by deducing what directory is out of place based on the compiler errors or by diffing the working copy with another clean checkout. But, this seems like a problem that SVN can diagnose in a second by giving me a list of all directories whose parent directory in the working copy doesn't match its parent directory in the repository. There there some way to have SVN give me a list like that? Thanks.

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  • Is it good practise to blank out inherited functionality that will not be used?

    - by Timo Kosig
    I'm wondering if I should change the software architecture of one of my projects. I'm developing software for a project where two sides (in fact a host and a device) use shared code. That helps because shared data, e.g. enums can be stored in one central place. I'm working with what we call a "channel" to transfer data between device and host. Each channel has to be implemented on device and host side. We have different kinds of channels, ordinary ones and special channels which transfer measurement data. My current solution has the shared code in an abstract base class. From there on code is split between the two sides. As it has turned out there are a few cases when we would have shared code but we can't share it, we have to implement it on each side. The principle of DRY (don't repeat yourself) says that you shouldn't have code twice. My thought was now to concatenate the functionality of e.g. the abstract measurement channel on the device side and the host side in an abstract class with shared code. That means though that once we create an actual class for either the device or the host side for that channel we have to hide the functionality that is used by the other side. Is this an acceptable thing to do: public abstract class MeasurementChannelAbstract { protected void MethodUsedByDeviceSide() { } protected void MethodUsedByHostSide() { } } public class DeviceMeasurementChannel : MeasurementChannelAbstract { public new void MethodUsedByDeviceSide() { base.MethodUsedByDeviceSide(); } } Now, DeviceMeasurementChannel is only using the functionality for the device side from MeasurementChannelAbstract. By declaring all methods/members of MeasurementChannelAbstract protected you have to use the new keyword to enable that functionality to be accessed from the outside. Is that acceptable or are there any pitfalls, caveats, etc. that could arise later when using the code?

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  • C Population Count of unsigned 64-bit integer with a maximum value of 15

    - by BitTwiddler1011
    I use a population count (hamming weight) function intensively in a windows c application and have to optimize it as much as possible in order to boost performance. More than half the cases where I use the function I only need to know the value to a maximum of 15. The software will run on a wide range of processors, both old and new. I already make use of the POPCNT instruction when Intel's SSE4.2 or AMD's SSE4a is present, but would like to optimize the software implementation (used as a fall back if no SSE4 is present) as much as possible. Currently I have the following software implementation of the function: inline int population_count64(unsigned __int64 w) { w -= (w 1) & 0x5555555555555555ULL; w = (w & 0x3333333333333333ULL) + ((w 2) & 0x3333333333333333ULL); w = (w + (w 4)) & 0x0f0f0f0f0f0f0f0fULL; return int(w * 0x0101010101010101ULL) 56; } So to summarize: (1) I would like to know if it is possible to optimize this for the case when I only want to know the value to a maximum of 15. (2) Is there a faster software implementation (for both Intel and AMD CPU's) than the function above?

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  • Peculiar JRE behaviour running RMI server under load, should I worry?

    - by darri
    I've been developing a minimalistic Java rich client CRUD application framework for the past few years, mostly as a hobby but also actively using it to write applications for my current employer. The framework provides database access to clients either via a local JDBC based connection or a lightweight RMI server. Last night I started a load testing application, which ran 100 headless clients, bombarding the server with requests, each client waiting only 1 - 2 seconds between running simple use cases, consisting of selecting records along with associated detail records from a simple e-store database (Chinook). This morning when I looked at the telemetry results from the server profiling session I noticed something which to me seemed strange (and made me keep the setup running for the remainder of the day), I don't really know what conclusions to draw from it. Here are the results: Memory GC activity Threads CPU load Interesting, right? So the question is, is this normal or erratic? Is this simply the JRE (1.6.0_03 on Windows XP) doing it's thing (perhaps related to the JRE configuration) or is my framework design somehow causing this? Running the server against MySQL as opposed to an embedded H2 database does not affect the pattern. I am leaving out the details of my server design, but I'll be happy to elaborate if this behaviour is deemed erratic.

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  • How to Sort a TreeList in Sitecore 6 in the Source

    - by Scott
    My team uses Sitecore 6 as content management system and then .Net to interface with Sitecore API. In many of our templates we make use of a Treelist. When adding a new item to the selected items Treelist it automatically puts the item at the bottom of the list. In some lists they get very large. In most cases end users would like to see these lists sorted descending by a Date field that is part of the templates that can be added as selected to the Treelist. Programmatically on the .Net side its very easy to handle this using Linq OrderByDescending and all displays great in the site to visitors. What I am trying to figure out is how to get it to display the same in Sitecore Content Editor. I've not found anything from Google search other than there seems to be a SortBy you can specify in the source but I tried this and can't get it to have any effect. Has anyone dealt with this before? Again, main goal is to sort items in a Treelist in the Sitecore Content Editor itself. Thanks for any input anyone has.

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  • What to throw in a C++ class wrapping a C library ?

    - by ereOn
    I have to create a set of wrapping C++ classes around an existing C library. For many objects of the C library, the construction is done by calling something like britney_spears* create_britney_spears() and the opposite function void free_britney_spears(britney_spears* brit). If the allocation of a britney_spears fails, create_britney_spears() returns NULL. This is, as far as I know, a very common pattern. Now I want to wrap this inside a C++ class. //britney_spears.hpp class BritneySpears { public: BritneySpears(); private: boost::shared_ptr<britney_spears> m_britney_spears; }; And here is the implementation: // britney_spears.cpp BritneySpears::BritneySpears() : m_britney_spears(create_britney_spears(), free_britney_spears) { if (!m_britney_spears) { // Here I should throw something to abort the construction, but what ??! } } So the question is in the code sample: What should I throw to abort the constructor ? I know I can throw almost anything, but I want to know what is usually done. I have no other information about why the allocation failed. Should I create my own exception class ? Is there a std exception for such cases ? Many thanks.

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  • WCF - Return object without serializing?

    - by Mayo
    One of my WCF functions returns an object that has a member variable of a type from another library that is beyond my control. I cannot decorate that library's classes. In fact, I cannot even use DataContractSurrogate because the library's classes have private member variables that are essential to operation (i.e. if I return the object without those private member variables, the public properties throw exceptions). If I say that interoperability for this particular method is not needed (at least until the owners of this library can revise to make their objects serializable), is it possible for me to use WCF to return this object such that it can at least be consumed by a .NET client? How do I go about doing that? Update: I am adding pseudo code below... // My code, I have control [DataContract] public class MyObject { private TheirObject theirObject; [DataMember] public int SomeNumber { get { return theirObject.SomeNumber; } // public property exposed private set { } } } // Their code, I have no control public class TheirObject { private TheirOtherObject theirOtherObject; public int SomeNumber { get { return theirOtherObject.SomeOtherProperty; } set { // ... } } } I've tried adding DataMember to my instance of their object, making it public, using a DataContractSurrogate, and even manually streaming the object. In all cases, I get some error that eventually leads back to their object not being explicitly serializable.

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  • Is there a free tool which can help visualize the logic of a stored procedure in SQL Server 2008 R2?

    - by Hamish Grubijan
    I would like to be able to plot a call graph of a stored procedure. I am not interested in every detail, and I am not concerned with dynamic SQL (although it would be cool to detect it and skip it maybe or mark it as such.) I would like the tool to generate a tree for me, given the server name, db name, stored proc name, a "call tree", which includes: Parent stored procedure. Every other stored procedure that is being called as a child of the caller. Every table that is being modified (updated or deleted from) as a child of the stored proc which does it. Hopefully it is clear what I am after; if not - please do ask. If there is not a tool that can do this, then I would like to try to write one myself. Python 2.6 is my language of choice, and I would like to use standard libraries as much as possible. Any suggestions? EDIT: For the purposes of bounty Warning: SQL syntax is COMPLEX. I need something that can parse all kinds of SQL 2008, even if it looks stupid. No corner cases barred :) EDIT2: I would be OK if all I am missing is graphics.

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  • Why onCreate() calling multiple times when i use Thread()?

    - by RajaReddy PolamReddy
    In my app i faced a problem with threads. i am using native code in my app. i try to load library and then calling native functions from the android code. 1. By using Threads() : PjsuaThread pjsuaThread = new PjsuaThread(); pjsuaThread.start(); thread code class PjsuaThread extends Thread { public void run() { if (pjsua_app.initApp() != 0) { // native function calling return; } else { } pjsua_app.startPjsua(ApjsuaActivity.CFG_FNAME); // native function calling finished = true; } When i use code like this, onCreate() function calling multiple times and able to load library and calling some functions properly, after some seconds onCreate calling again because of that it's crashing. 2. Using AsyncTask(): And also i used AsyncTask< for this requirement, it's crashing the application( crashing in lib code ). not able to open any functions class SipTask extends AsyncTask<Void, String, Void> { protected Void doInBackground(Void... args) { if (pjsua_app.initApp() != 0) { return null; } else { } pjsua_app.startPjsua(ApjsuaActivity.CFG_FNAME); finished = true; return null; } @Override protected void onPostExecute(Void result) { super.onPostExecute(result); Log.i(TAG, "On POst "); } } What is annoying is that in most cases it is not the missing library, it's tried to able to load the lib crashing in between. any one know the reason ?

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  • What are good examples of perfectly acceptable approaches to development that are NOT test driven development (TDD)?

    - by markbruns
    The TDD cycle is test, code, refactor, (repeat) and then ship. TDD implies development that is driven by testing, specifically that means understanding requirements and then writing tests first before developing or writing code. My natural inclination is a philosophical bias in favor of TDD; I would like to be convinced that there are other approaches that now work well or even better than TDD so I have asked this question. What are examples of perfectly acceptable approaches that NOT test driven development? I can think of plenty approaches that are not TDD but could be a lot more trouble than what they are worth ... it's not moral judgement, it's just that they are cost more than they are worth ... the following are simply examples of things that might be ok as learning exercises, but approaches I'd find to be NOT acceptable in serious production and NOT TDD might include: Inspecting quality into your product -- Focusing efforts on developing a proficiency in testing/QA can be problematic, especially if you don't work on the requirements and development side first ... symptom of this include bug triaging where the developers have so many different bugs to deal with it, it is necessary to employ a form of triage -- each development cycle gets worse and worse, programmers work more and more hours, sleep less and less, struggle to keep going in death march until they are consumed. Superstition ... believing in things that you don't understand -- this would involve borrowing code that you believe has been proven or tested from somewhere, e.g. legacy code, a magic code starter wizard or an open source project, and you go forward hacking up a storm of modifications, sliding FaceBook Connect into your the user interface, inventing some new magic features on the fly (e.g. a mashup using the Twitter API, GoogleMaps API and maybe Zappos API), showing off your cool new "product" to a few people and then writing up a simple "specification" and list of "test cases" and turning that over to Mechanical Turk for testing.

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  • Sorting page flow for has_many in Rails

    - by Gareth
    I have a page flow allowing the user to choose an object ("Player") to add to a has_many :players association in another model. 1 => List existing players for object [Enter player name] 2 => List of matching players [Select player] 3 => Confirmation page [Press 'Add'] 4 => Done I want users to be able to choose "New Player" instead of selecting a player at step 2, in which case the user will go through the standard New Player process elsewhere on the site. However, after that's done, the user should return to step 3 with the new player in place. I don't know what the best way is to implement this. I don't want to duplicate the player creation code, but I don't want to dirty up the player creation code too much just for this case. I also don't want to start sticking IDs in the session if I can help it. It's fine in simple cases but if the user ever has two windows/tabs then things start behaving badly. What do you think?

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  • In Castle Windsor, can I register a Interface component and get a proxy of the implementation?

    - by Thiado de Arruda
    Lets consider some cases: _windsor.Register(Component.For<IProductServices>().ImplementedBy<ProductServices>().Interceptors(typeof(SomeInterceptorType)); In this case, when I ask for a IProductServices windsor will proxy the interface to intercept the interface method calls. If instead I do this : _windsor.Register(Component.For<ProductServices>().Interceptors(typeof(SomeInterceptorType)); then I cant ask for windsor to resolve IProductServices, instead I ask for ProductServices and it will return a dynamic subclass that will intercept virtual method calls. Of course the dynamic subclass still implements 'IProductServices' My question is : Can I register the Interface component like the first case, and get the subclass proxy like in the second case?. There are two reasons for me wanting this: 1 - Because the code that is going to resolve cannot know about the ProductServices class, only about the IProductServices interface. 2 - Because some event invocations that pass the sender as a parameter, will pass the ProductServices object, and in the first case this object is a field on the dynamic proxy, not the real object returned by windsor. Let me give an example of how this can complicate things : Lets say I have a custom collection that does something when their items notify a property change: private void ItemChanged(object sender, PropertyChangedEventArgs e) { int senderIndex = IndexOf(sender); SomeActionOnItemIndex(senderIndex); } This code will fail if I added an interface proxy, because the sender will be the field in the interface proxy and the IndexOf(sender) will return -1.

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  • Has inheritance become bad?

    - by mafutrct
    Personally, I think inheritance is a great tool, that, when applied reasonably, can greatly simplify code. However, I seems to me that many modern tools dislike inheritance. Let's take a simple example: Serialize a class to XML. As soon as inheritance is involved, this can easily turn into a mess. Especially if you're trying to serialize a derived class using the base class serializer. Sure, we can work around that. Something like a KnownType attribute and stuff. Besides being an itch in your code that you have to remember to update every time you add a derived class, that fails, too, if you receive a class from outside your scope that was not known at compile time. (Okay, in some cases you can still work around that, for instance using the NetDataContract serializer in .NET. Surely a certain advancement.) In any case, the basic principle still exists: Serialization and inheritance don't mix well. Considering the huge list of programming strategies that became possible and even common in the past decade, I feel tempted to say that inheritance should be avoided in areas that relate to serialization (in particular remoting and databases). Does that make sense? Or am messing things up? How do you handle inheritance and serialization?

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  • Can't declare an abstract method private....

    - by Zombies
    I want to do this, yet I can't. Here is my scenario and rational. I have an abstract class for test cases that has an abstract method called test(). The test() method is to be defined by the subclass; it is to be implemented with logic for a certain application, such as CRMAppTestCase extends CompanyTestCase. I don't want the test() method to be invoked directly, I want the super class to call the test() method while the sub class can call a method which calls this (and does other work too, such as setting a current date-time right before the test is executed for example). Example code: public abstract class CompanyTestCase { //I wish this would compile, but it cannot be declared private private abstract void test(); public TestCaseResult performTest() { //do some work which must be done and should be invoked whenever //this method is called (it would be improper to expect the caller // to perform initialization) TestCaseResult result = new TestCaseResult(); result.setBeginTime(new Date()); long time = System.currentTimeMillis(); test(); //invoke test logic result.setDuration(System.currentTimeMillis() - time); return result; } } Then to extend this.... public class CRMAppTestCase extends CompanyTestCase { public void test() { //test logic here } } Then to call it.... TestCaseResult result = new CRMAppTestCase().performTest();

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  • How do I daemonize an arbitrary script in unix?

    - by dreeves
    I'd like a daemonizer that can turn an arbitrary, generic script or command into a daemon. There are two common cases I'd like to deal with: I have a script that should run forever. If it ever dies (or on reboot), restart it. Don't let there ever be two copies running at once (detect if a copy is already running and don't launch it in that case). I have a simple script or command line command that I'd like to keep executing repeatedly forever (with a short pause between runs). Again, don't allow two copies of the script to ever be running at once. Of course it's trivial to write a "while(true)" loop around the script in case 2 and then apply a solution for case 1, but a more general solution will just solve case 2 directly since that applies to the script in case 1 as well (you may just want a shorter or no pause if the script is not intended to ever die (of course if the script really does never die then the pause doesn't actually matter)). Note that the solution should not involve, say, adding file-locking code or PID recording to the existing scripts. More specifically, I'd like a program "daemonize" that I can run like % daemonize myscript arg1 arg2 or, for example, % daemonize 'echo `date` >> /tmp/times.txt' which would keep a growing list of dates appended to times.txt. (Note that if the argument(s) to daemonize is a script that runs forever as in case 1 above, then daemonize will still do the right thing, restarting it when necessary.) I could then put a command like above in my .login and/or cron it hourly or minutely (depending on how worried I was about it dying unexpectedly). NB: The daemonize script will need to remember the command string it is daemonizing so that if the same command string is daemonized again it does not launch a second copy. Also, the solution should ideally work on both OS X and linux but solutions for one or the other are welcome. (If I'm thinking of this all wrong or there are quick-and-dirty partial solutions, I'd love to hear that too.)

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  • ARC and __unsafe_unretained

    - by J Shapiro
    I think I have a pretty good understanding of ARC and the proper use cases for selecting an appropriate lifetime qualifiers (__strong, __weak, __unsafe_unretained, and __autoreleasing). However, in my testing, I've found one example that doesn't make sense to me. As I understand it, both __weak and __unsafe_unretained do not add a retain count. Therefore, if there are no other __strong pointers to the object, it is instantly deallocated. The only difference in this process is that __weak pointers are set to nil, and __unsafe_unretained pointers are left alone. If I create a __weak pointer to a simple, custom object (composed of one NSString property), I see the expected (null) value when trying to access a property: Test * __weak myTest = [[Test alloc] init]; myTest.myVal = @"Hi!"; NSLog(@"Value: %@", myTest.myVal); // Prints Value: (null) Similarly, I would expect the __unsafe_unretained lifetime qualifier to cause a crash, due to the resulting dangling pointer. However, it doesn't. In this next test, I see the actual value: Test * __unsafe_unretained myTest = [[Test alloc] init]; myTest.myVal = @"Hi!"; NSLog(@"Value: %@", myTest.myVal); // Prints Value: Hi! Why doesn't the __unsafe_unretained object become deallocated?

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  • Memcached getDelayed alternative implementation

    - by iBobo
    I would like to use getDelayed on the PHP Memcached extension but I think it's not implemented in the right way. Right now you ask for some keys and then retrieve all of them with fetch() and fetchAll(). But imagine a scenario where I need to retrieve 15 keys used in different parts of the page which I don't know in advance, but I can ask the various objects to give me the list. What I want is give the Memcached instance this list (each component would give its part) then later when I need them retrieve from the instance, but not all of them at once: each component would take the one it needs. Basically if I were to implement this I would prohibit using getDelayed alone and implement a bookGet($keys) method where you would add the keys to book (which actually calls getDelayed), and redefine get to handle these three cases: key is booked and retrieved - return the value; key is booked but not retrieved - go and force the fetch of the booked keys and return the correct value; key not booked - do a normal lookup. I want to know if this makes sense, your thoughts on the subject and if someone already implemented this or maybe PECL Memcached already works this way and actually the documentation doesn't explain it correctly.

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  • Iterative Reduction to Null Matrix

    - by user1459032
    Here's the problem: I'm given a matrix like Input: 1 1 1 1 1 1 1 1 1 At each step, I need to find a "second" matrix of 1's and 0's with no two 1's on the same row or column. Then, I'll subtract the second matrix from the original matrix. I will repeat the process until I get a matrix with all 0's. Furthermore, I need to take the least possible number of steps. I need to print all the "second" matrices in O(n) time. In the above example I can get to the null matrix in 3 steps by subtracting these three matrices in order: Expected output: 1 0 0 0 1 0 0 0 1 0 0 1 1 0 0 0 1 0 0 1 0 0 0 1 1 0 0 I have coded an attempt, in which I am finding the first maximum value and creating the second matrices based on the index of that value. But for the above input I am getting 4 output matrices, which is wrong: My output: 1 0 0 0 1 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 1 0 1 0 My solution works for most of the test cases but fails for the one given above. Can someone give me some pointers on how to proceed, or find an algorithm that guarantees optimality? Test case that works: Input: 0 2 1 0 0 0 3 0 0 Output 0 1 0 0 0 0 1 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0

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  • Overlaying several CLR reference fields with each other in explicit struct?

    - by thr
    Edit: I'm well aware of that this works very well with value types, my specific question is about using this for reference types. I've been tinkering around with structs in .NET/C#, and I just found out that you can do this: using System; using System.Runtime.InteropServices; namespace ConsoleApplication1 { class Foo { } class Bar { } [StructLayout(LayoutKind.Explicit)] struct Overlaid { [FieldOffset(0)] public object AsObject; [FieldOffset(0)] public Foo AsFoo; [FieldOffset(0)] public Bar AsBar; } class Program { static void Main(string[] args) { var overlaid = new Overlaid(); overlaid.AsObject = new Bar(); Console.WriteLine(overlaid.AsBar); overlaid.AsObject = new Foo(); Console.WriteLine(overlaid.AsFoo); Console.ReadLine(); } } } Basically circumventing having to do dynamic casting during runtime by using a struct that has an explicit field layout and then accessing the object inside as it's correct type. Now my question is: Can this lead to memory leaks somehow, or any other undefined behavior inside the CLR? Or is this a fully supported convention that is usable without any issues? I'm aware that this is one of the darker corners of the CLR, and that this technique is only a viable option in very few specific cases.

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  • How to override jquery's show() and hide() functions

    - by Max Williams
    hi all Short version of question: see title Long version of question: I've used jquery's show() and hide() functions extensively in my code and just encountered a bit of a problem: they work by changing the display attribute of the element to 'block' or 'none' respectively, so that if you have somethin that has display: inline and then hide and show it, you've changed its display to block, which screws up the layout in a couple of cases. In my code, whenever i want something to be hidden initially i give it a class 'hidden'. This class is simply {display: none}. I'd like the change show and hide to remove or add this class, instead of directly changing the display attribute, so that if you add the hidden class and then remove it again (ie hide and show something) then it's back to exactly how it was to start off with (since adding a class overrides the attributes rather than directly changing them). Something like this (this is a little pseucodey as i don't know how to set the function up properly - let's assume that 'this' is the object that show/hide was called on) function show(){ this.removeClass("hidden"); } function hide(){ this.addClass("hidden"); } how and where would i go about overriding the jquery methods? (I'm not a javascript expert) thanks - max

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