Search Results

Search found 8397 results on 336 pages for 'implementation'.

Page 259/336 | < Previous Page | 255 256 257 258 259 260 261 262 263 264 265 266  | Next Page >

• Testing ActionFilterAttributes with MSpec

  - by Tomas Lycken

  I'm currently trying to grasp MSpec, mainly to learn new ways of (T/B)DD to be able to make an educated decision on which technology to use. Previously, I've mostly (read: only) used the built-in MSTest framework with Moq, so BDD is quite new for me. I'm writing an ASP.NET MVC app, and I want to implement PRG. Last time I did this, I used action filters to export and import ModelState via TempData, so that I could return a RedirectResult and the validation errors would still be there when the user got the view. I tested that scenario by verifying two things: a) That the ExportModelStateAttribute I had written was applied (among tests for my controller) b) That the attribute worked (among tests for action filter attributes) However, in BDD I've understood I should be even more concerned with behavior, and even less with implementation. This means I should probably just verify that the model state is in tempdata when the action has finished executing - not necessarily that it's done via an attribute. To further complicate things, attributes are not run when calling the action directly in the test, so I can't just call the action and see if the job's been done. How should I spec/test this in MSpec?

  Read the article

• Algorithm for count-down timer that can add on time

  - by Person

  I'm making a general timer that has functionality to count up from 0 or count down from a certain number. I also want it to allow the user to add and subtract time. Everything is simple to implement except for the case in which the timer is counting down from some number, and the user adds or subtracts time from it. For example: (m_clock is an instance of SFML's Clock) float Timer::GetElapsedTime() { if ( m_forward ) { m_elapsedTime += m_clock.GetElapsedTime() - m_elapsedTime; } else { m_elapsedTime -= m_elapsedTime - m_startingTime + m_clock.GetElapsedTime(); } return m_elapsedTime; } To be a bit more clear, imagine that the timer starts at 100 counting down. After 10 seconds, the above function would look like 100 -= 100 - 100 + 10 which equals 90. If it was called after 20 more seconds it would look like 90 -= 90 - 100 + 30 which equals 70. This works for normal counting, but if the user calls AddTime() ( just m_elapsedTime += arg ) then the algorithm for backwards counting fails miserably. I know that I can do this using more members and keeping track of previous times, etc. but I'm wondering whether I'm missing some implementation that is extremely obvious. I'd prefer to keep it as simple as possible in that single operation.

  Read the article

• Thread-safe data structure design

  - by Inso Reiges

  Hello, I have to design a data structure that is to be used in a multi-threaded environment. The basic API is simple: insert element, remove element, retrieve element, check that element exists. The structure's implementation uses implicit locking to guarantee the atomicity of a single API call. After i implemented this it became apparent, that what i really need is atomicity across several API calls. For example if a caller needs to check the existence of an element before trying to insert it he can't do that atomically even if each single API call is atomic: if(!data_structure.exists(element)) { data_structure.insert(element); } The example is somewhat awkward, but the basic point is that we can't trust the result of "exists" call anymore after we return from atomic context (the generated assembly clearly shows a minor chance of context switch between the two calls). What i currently have in mind to solve this is exposing the lock through the data structure's public API. This way clients will have to explicitly lock things, but at least they won't have to create their own locks. Is there a better commonly-known solution to these kinds of problems? And as long as we're at it, can you advise some good literature on thread-safe design? EDIT: I have a better example. Suppose that element retrieval returns either a reference or a pointer to the stored element and not it's copy. How can a caller be protected to safely use this pointer\reference after the call returns? If you think that not returning copies is a problem, then think about deep copies, i.e. objects that should also copy another objects they point to internally. Thank you.

  Read the article

• Is there a way to implement Caliburn-like co-routines in VB.NET since there's no yield keyword

  - by Miroslav Popovic

  Note that I'm aware of other yield in vb.net questions here on SO. I'm playing around with Caliburn lately. Bunch of great stuff there, including co-routines implementation. Most of the work I'm doing is C# based, but now I'm also creating an architecture guideline for a VB.NET only shop, based on Rob's small MVVM framework. Everything looks very well except using co-routines from VB. Since VB 10 is used, we can try something like Bill McCarthy's suggestion: Public Function Lines(ByVal rdr as TextReader) As IEnumerable(Of String) Return New GenericIterator(Of String) (Function(ByRef nextItem As String) As Boolean nextItem = rdr.ReadLine Return nextItem IsNot Nothing End Function) End Function I'm just failing to comprehend how a little more complex co-routine method like the one below (taken from Rob's GameLibrary) could be written in VB: public IEnumerable<IResult> ExecuteSearch() { var search = new SearchGames { SearchText = SearchText }.AsResult(); yield return Show.Busy(); yield return search; var resultCount = search.Response.Count(); if (resultCount == 0) SearchResults = _noResults.WithTitle(SearchText); else if (resultCount == 1 && search.Response.First().Title == SearchText) { var getGame = new GetGame { Id = search.Response.First().Id }.AsResult(); yield return getGame; yield return Show.Screen<ExploreGameViewModel>() .Configured(x => x.WithGame(getGame.Response)); } else SearchResults = _results.With(search.Response); yield return Show.NotBusy(); } Any idea how to achieve that, or any thoughts on using Caliburn co-routines in VB?

  Read the article

• ObjC internals. Why my duck typing attempt failed?

  - by Piotr Czapla

  I've tried to use id to create duck typing in objective-c. The concept looks fine in theory but failed in practice. I was unable to use any parameters in my methods. The methods were called but parameters were wrong. I was getting BAD_ACESS for objects and random values for primitives. I've attached a simple example below. The question: Does any one knows why the methods parameters are wrong? What is happening under the hood of the objective-c? Note: I'm interest in the details. I know how to make the example below work. An example: I've created a simple class Test that is passed to an other class using property id test. @implementation Test - (void) aSampleMethodWithFloat:(float) f andInt: (int) i { NSLog(@"Parameters: %f, %i\n", f, i); } @end Then in the class the following loop is executed: for (float f=0.0f; f < 100.0f ; f += 0.3f) { [self.test aSampleMethodWithOneFloatParameter: f]; // warning: no method found. } Here is the output that I'm getting. As you can see the method was called but the parameters were wrong. Parameters: 0.000000, 0 Parameters: -0.000000, 1069128089 Parameters: -0.000000, 1070176665 Parameters: 2.000000, 1070805811 Parameters: -0.000000, 1071225241 Parameters: 0.000000, 1071644672 Parameters: 2.000000, 1071854387 Parameters: 36893488147419103232.000000, 1072064102 Parameters: -0.000000, 1072273817 Parameters: -36893488147419103232.000000, 1072483532

  Read the article

• How do I mock a method with an open array parameter in PascalMock?

  - by Oliver Giesen

  I'm currently in the process of getting started with unit testing and mocking for good and I stumbled over the following method that I can't seem to fabricate a working mock implementation for: function GetInstance(const AIID: TGUID; out AInstance; const AArgs: array of const; const AContextID: TImplContextID = CID_DEFAULT): Boolean; (TImplContextID is just an alias for Integer) I thought it would have to look something like this: function TImplementationProviderMock.GetInstance( const AIID: TGUID; out AInstance; const AArgs: array of const; const AContextID: TImplContextID): Boolean; begin Result := AddCall('GetInstance') .WithParams([@AIID, AContextID]) .ReturnsOutParams([AInstance]) .ReturnValue; end; But the compiler complains about the .ReturnsOutParams([AInstance]) saying "Bad argument type in variable type array constructor.". Also I haven't found a way to specify the open array parameter AArgs at all. Also, is using the @-notation for the TGUID-typed parameter the right way to go? Is it possible to mock this method with the current version of PascalMock at all? Update: I now realize I got the purpose of ReturnsOutParams completely wrong: It's intended to be used for populating the values to be returned when defining the expectations rather than for mocking the call itself. I now think the correct syntax for mocking the out parameter would probably have to look more like this: function TImplementationProviderMock.GetInstance( const AIID: TGUID; out AInstance; const AArgs: array of const; const AContextID: TImplContextID): Boolean; var lCall: TMockMethod; begin lCall := AddCall('GetInstance').WithParams([@AIID, AContextID]); Pointer(AInstance) := lCall.OutParams[0]; Result := lCall.ReturnValue; end; The questions that remain are how to mock the open array parameter AArgs and whether passing the TGUID argument (i.e. a value type) by address will work out...

  Read the article

• How can I compare market data feed sources for quality and latency improvement?

  - by yves Baumes

  I am in the very first stages of implementing a tool to compare 2 market data feed sources in order to prove the quality of new developed sources to my boss ( meaning there are no regressions, no missed updates, or wrong ), and to prove latencies improvement. So the tool I need must be able to check updates differences as well as to tell which source is the best (in term of latency). Concrectly, reference source could be Reuters while the other one is a Feed handler we develop internally. People warned me that updates might not arrive in the same order as Reuters implementation could differs totally from ours. Therefore a simple algorithm based on the fact that updates could arrive in the same order is likely not to work. My very first idea would be to use fingerprint to compare feed sources, as Shazaam application does to find the title of the tube you are submitting. Google told me it is based on FFT. And I was wondering if signal processing theory could behaves well with market access applications. I wanted to know your own experience in that field, is that possible to develop a quite accurate algorithm to meet the needs? What was your own idea? What do you think about fingerprint based comparison?

  Read the article

• Need help make these classes use Visitor Pattern and generics

  - by Shervin

  Hi. I need help to generify and implement the visitor pattern. We are using tons of instanceof and it is a pain. I am sure it can be modified, but I am not sure how to do it. Basically we have an interface ProcessData public interface ProcessData { public setDelegate(Object delegate); public Object getDelegate(); //I am sure these delegate methods can use generics somehow } Now we have a class ProcessDataGeneric that implements ProcessData public class ProcessDataGeneric implements ProcessData { private Object delegate; public ProcessDataGeneric(Object delegate) { this.delegate = delegate; } } Now a new interface that retrieves the ProcessData interface ProcessDataWrapper { public ProcessData unwrap(); } Now a common abstract class that implements the wrapper so ProcessData can be retrieved @XmlSeeAlso( { ProcessDataMotorferdsel.class,ProcessDataTilskudd.class }) public abstract class ProcessDataCommon implements ProcessDataWrapper { protected ProcessData unwrapped; public ProcessData unwrap() { return unwrapped; } } Now the implementation public class ProcessDataMotorferdsel extends ProcessDataCommon { public ProcessDataMotorferdsel() { unwrapped = new ProcessDataGeneric(this); } } similarly public class ProcessDataTilskudd extends ProcessDataCommon { public ProcessDataTilskudd() { unwrapped = new ProcessDataGeneric(this); } } Now when I use these classes, I always need to do instanceof ProcessDataCommon pdc = null; if(processData.getDelegate() instanceof ProcessDataMotorferdsel) { pdc = (ProcessDataMotorferdsel) processData.getDelegate(); } else if(processData.getDelegate() instanceof ProcessDataTilskudd) { pdc = (ProcessDataTilskudd) processData.getDelegate(); } I know there is a better way to do this, but I have no idea how I can utilize Generics and the Visitor Pattern. Any help is GREATLY appreciated.

  Read the article

• iphone NSMutableArray loses objects at end of method

  - by Brodie4598

  Hello - in my app, an NSMutableArray is populated with an object in viewDidLoad (eventually there will be many objects but I'm just doing one til I get it working right). I also start a timer that starts a method that needs to access the NSMutableArray every few seconds. The NSMutableArray works fine in viewDidLoad, but as soon as that method is finished, it loses the object. myApp.h @interface MyApp : UIViewController { NSMutableArray *myMutableArray; NSTimer *timer; } @property (nonatomic, retain) NSMutableArray *myMutableArray; @property (nonatomic, retain) NSTimer *timer; @end myApp.m #import "MyApp.h" @implementation MyApp @synthesize myMutableArray; - (void) viewDidLoad { cycleTimer = [NSTimer scheduledTimerWithTimeInterval:4.0 target:self selector:@selector(newCycle) userInfo: nil repeats:YES]; MyObject *myCustomUIViewObject = [[MyObject alloc]init]; [myMutableArray addObject:myCustomUIViewObject]; [myCustomUIViewObject release]; NSLog(@"%i",[myMutableArray count]); /////outputs "1" } -(void) newCycle { NSLog(@"%i",[myMutableArray count]); /////outputs "0" ?? why is this?? }

  Read the article

• php OOP function declarations

  - by kris

  I'm a big fan of OOP in php, but i feel like defining class methods gets disorganized so fast. I have a pretty good background in OOP in C++, and i am pretty comfortable with how it is handled there, and am curious if there are ways to do it similarly in php. To be more specific, here is what i mean. I like how in C++ you can define a class header (myclass.h) and then define the actual details of the functions in the implementation file (myclass.cc). Ive found that this can easily be replicated using interfaces in php, but i havent found a good solution for the following: I like to organize my code in C++ in different files based on how they are accessed, so for example, public methods that can be called outside of the class would be in 1 place, and private methods would be organized somewhere else - this is personal preference. Ive tried to define class methods in php like: private function MyPHPClass::myFunction(){ } when the definition isnt directly inside the class block( { } ), but i havent had any success doing this. Ive been through all of the pages on php.net, but couldnt find anything like this. Im assuming that there is no support for something like this, but thought i would ask anyway. thanks

  Read the article

• Why is my UITableView not being set?

  - by Jamie L

  I checked using the debbuger in the viewDidLoad method and tracerTableView is 0x0 which i assume means it is nil. I don't understand. I should go ahaed say yes I have already checked my nib file and yes all the connections are correct. Here is the header file and the begging of the .m. ///////////// .h file //////////// @interface TrackerListController : UITableViewController { // The mutable (modifiable) dictionary days holds all the data for the days tab NSMutableArray *trackerList; UITableView *tracerTableView; } @property (nonatomic, retain) NSMutableArray *trackerList; @property (nonatomic, retain) IBOutlet UITableView. *tracerTableView; //The addPackage: method is invoked when the user taps the addbutton created at runtime. -(void) addPackage : (id) sender; @end /////////////////////////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////// .m file ////////////////////////////////////// @implementation TrackerListController @synthesize trackerList, tracerTableView; (void)viewDidLoad { [super viewDidLoad]; self.title = @"Package Tracker"; self.navigationItem.leftBarButtonItem = self.editButtonItem; UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addPackage:)]; // Set up the Add custom button on the right of the navigation bar self.navigationItem.rightBarButtonItem = addButton; [addButton release]; // Release the addButton from memory since it is no longer needed }

  Read the article

• C++0x rvalue references and temporaries

  - by Doug

  (I asked a variation of this question on comp.std.c++ but didn't get an answer.) Why does the call to f(arg) in this code call the const ref overload of f? void f(const std::string &); //less efficient void f(std::string &&); //more efficient void g(const char * arg) { f(arg); } My intuition says that the f(string &&) overload should be chosen, because arg needs to be converted to a temporary no matter what, and the temporary matches the rvalue reference better than the lvalue reference. This is not what happens in GCC and MSVC. In at least G++ and MSVC, any lvalue does not bind to an rvalue reference argument, even if there is an intermediate temporary created. Indeed, if the const ref overload isn't present, the compilers diagnose an error. However, writing f(arg + 0) or f(std::string(arg)) does choose the rvalue reference overload as you would expect. From my reading of the C++0x standard, it seems like the implicit conversion of a const char * to a string should be considered when considering if f(string &&) is viable, just as when passing a const lvalue ref arguments. Section 13.3 (overload resolution) doesn't differentiate between rvalue refs and const references in too many places. Also, it seems that the rule that prevents lvalues from binding to rvalue references (13.3.3.1.4/3) shouldn't apply if there's an intermediate temporary - after all, it's perfectly safe to move from the temporary. Is this: Me misreading/misunderstand the standard, where the implemented behavior is the intended behavior, and there's some good reason why my example should behave the way it does? A mistake that the compiler vendors have somehow all made? Or a mistake based on common implementation strategies? Or a mistake in e.g. GCC (where this lvalue/rvalue reference binding rule was first implemented), that was copied by other vendors? A defect in the standard, or an unintended consequence, or something that should be clarified?

  Read the article

• What is a good automated data import method for SQL Server?

  - by Joel Potter

  I'm in the process of porting some SQL Server 2005 databases to SQL Server 2008. One of these databases has an associated import application (Windows task) which uses SSIS with a DTS package to import a large dataset from an MS Access database nightly. In upgrading to SQL Server 2008, I discovered that I can't run the same console application which has been performing the imports due to the missing manageddts DLL in SQL Server 2008. It's several years old and in need of a rewrite for various reason, plus, I've been fairly unhappy with DTS in general. The original reason DTS was chosen was for speed (5 min import time compared to 30+ for ADO.NET). The format of the data to import is out of my control (the client likes Access). I would also like to be able to run the import from a machine completely separate from the server hosting SQL Server and preferably with minimal SQL features installed. Options I've considered: Creating an Access application to connect to both databases (SQL Server and Access) and perform the import (Ugh!) Revisiting ADO.NET to see if the original implementation was poorly written. Updated SSIS packages. What other technologies should I be considering for this job?

  Read the article

• Cross-Platform Camera API

  - by Karim

  Hi, I'm now building a video transforming filter that have to transform video frames in real-time. One of the key requirements of the filter is to have high performance to minimize the number of dropped frames during the transform. Another requirement that is of lower priority but also nice to have is to make it cross-platform (both PC's and Mobile devices). The application is built in C++. Now my question is: is there any API that is more portable and has a similar or better performance characteristics than DirectShow? as DirectShow's portability is only limited to Windows-based devices (PCs and Windows Mobile&CE platforms). Also I've notices that for example using HTC's custom camera API has far better performance than what DirectShow offers. If you want to check this, try to build a filter in DirectShow that will multiply each color by 2 and render that in real-time from camera on the screen. Then do the same with HTC's API. There is almost 4-5x performance boost with vendor's specific API. So it'd be very nice if the library used the device-specific implementation of the driver, as performance is critical when doing this transforms on a mobile device (which is about ~500 MHz).

  Read the article

• C# Fun with Generics - Mutual Dependencies

  - by Kenneth Cochran

  As an experiment I'm trying to write a generic MVP framework. I started with: public interface IPresenter<TView> where TView: IView<IPresenter<... { TView View { get; set;} } public interface IView<TPresenter> where TPresenter:IPresenter<IView<... { TPresenter Presenter { get; set; } } Obviously this can't work because the types of TView and TPresenter can't be resolved. You'd be writing Type<Type<... forever. So my next attempt looked like this: public interface IView<T> where T:IPresenter { ... } public interface IView:IView<IPresenter> { } public interface IPresenter<TView> where TView: IView { ... } public interface IPresenter: IPresenter<IView> { ... } This actually compiles and you can even inherit from these interfaces like so: public class MyView : IView, IView<MyPresenter> { ... } public class MyPresenter : IPresenter, IPresenter<MyView> { ... } The problem is in the class definition you have to define any members declared in the generic type twice. Not ideal but it still compiles. The problem's start creeping up when you actually try to access the members of a Presenter from a View or vice versa. You get an Ambiguous reference when you try to compile. Is there any way to avoid this double implementation of a member when you inherit from both interfaces? Is it even possible to resolve two mutually dependent generic types at compile time?

  Read the article

• Change title of UINavigationBar

  - by Lemmy

  I've created a view-based application. I've placed a Navigation Bar on the view and two buttons. I'd like to change the title of the nav bar after pressing the buttons. In IB I've connected the buttons with the corresponding actions. Debugging shows that the actions are getting called but the title of the nav bar is not changed. Kindly help! // // NavBarViewController.h #import <UIKit/UIKit.h> @interface NavBarViewController : UIViewController { } -(IBAction) clickedOne: (id)sender; -(IBAction) clickedTwo: (id)sender; @end // // NavBarViewController.m #import "NavBarViewController.h" @implementation NavBarViewController -(IBAction) clickedOne: (id)sender { self.navigationItem.title = @"1"; } -(IBAction) clickedTwo: (id)sender { self.navigationItem.title = @"2"; } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } - (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)dealloc { [super dealloc]; } @end

  Read the article

• Xerces C++ SAX Parsing Problem: expected class-name before '{' token

  - by aduric

  I'm trying to run through an example given for the C++ Xerces XML library implementation. I've copied the code exactly, but I'm having trouble compiling it. error: expected class-name before '{' token I've looked around for a solution, and I know that this error can be caused by circular includes or not defining a class before it is used, but as you can see from the code, I only have 2 files: MySAXHandler.hpp and MySAXHandler.cpp. However, the MySAXHandler class is derived from HandlerBase, which is included. MyHandler.hpp #include <xercesc/sax/HandlerBase.hpp> class MySAXHandler : public HandlerBase { public: void startElement(const XMLCh* const, AttributeList&); void fatalError(const SAXParseException&); }; MySAXHandler.cpp #include "MySAXHandler.hpp" #include <iostream> using namespace std; MySAXHandler::MySAXHandler() { } void MySAXHandler::startElement(const XMLCh* const name, AttributeList& attributes) { char* message = XMLString::transcode(name); cout << "I saw element: "<< message << endl; XMLString::release(&message); } void MySAXHandler::fatalError(const SAXParseException& exception) { char* message = XMLString::transcode(exception.getMessage()); cout << "Fatal Error: " << message << " at line: " << exception.getLineNumber() << endl; XMLString::release(&message); } I'm compiling like so: g++ -L/usr/local/lib -lxerces-c -I/usr/local/include -c MySAXHandler.cpp I've looked through the HandlerBase and it is defined, so I don't know why I can't derive a class from it? Do I have to override all the virtual functions in HandlerBase? I'm kinda new to C++. Thanks in advance.

  Read the article

• ASP .NET Added Event Handlers to buttons on Page_Load. Event handlers do not fire the first click, b

  - by John

  Background: I am customizing an existing ASP .NET / C# application. It has it's own little "framework" and conventions for developers to follow when extending/customizing its functionality. I am currently extending some of it's administrative functionality, to which the framework provides a contract to enforce implementation of the GetAdministrationInterface() method, which returns System.Web.UI.Control. This method is called during the Page_Load() method of the page hosting the GUI interface. Problem: I have three buttons in my GUI, each of which have been assigned an Event Handler. My administration GUI loads up perfectly fine, but clicking any of the buttons doesn't do what I expect them to do. However, when I click them a second time, the buttons work. I placed breakpoints at the the beginning of each event handler method and stepped through my code. On the first click, none of the event handlers are triggered. On the second click, they are triggered. Any ideas? Example of Button Definition Button btn = new Button(); btn.Text = "Click Me Locked Screen"; bth.Click += new EventHandler(Btn_Click); Example of Event Handler Method Definition void Btn_Click(object sender, EventArgs e) { // Do Something }

  Read the article

• What is the best prctice for using security in JAX-WS

  - by kislo_metal

  Here is scenario : I have some web services (JAX-WS) that need to be secured. Currently for authentication needs I providing addition SecurityWService that give authorized user some userid & sessionid that is need to be described in request to other services. It would be more better to use some java security. We have many of them but could not defined what is better to use. Q1 : It is understand that I should use SSL in transport layer, but what should I use for user authorization. Is there is better way to establishing session, validating user etc. ? Here is some key description : Most web services clents is php based. I am using jax-ws implementation as a Stateless session EJB. Deploying to glassfish v3. Q2: what is the best framework / technology for user authorization / authentication in case of using JSF 2.0 and ejb3.1 technologies ( Realms? WSIT? )? Thank You!

  Read the article

• How frequently IP packets are fragmented at the source host?

  - by Methos

  I know that if IP payload MTU then routers usually fragment the IP packet. Finally all the fragmented packets are assembled at the destination using the fields IP-ID, IP fragment offsets and fragmentation flags. Max length of IP payload is 64K. Thus its very plausible for L4 to hand over payload which is 64K. If the L2 protocol is Ethernet, which often is the case, then the MTU will be about 1600 bytes. Hence IP packet will be fragmented at the source host itself. However, a quick search about IP implementation in Linux tells me that in recent kernels, L4 protocols are fragment friendly i.e. they try to save the fragmentation work for IP by handing over buffers of size which is close to MTU. Considering these two facts, I am wondering about how frequently does the IP packet gets fragmented at the source host itself. Does it occur sometimes/rarely/never? Does anyone know if there are exceptions to the rule of fragmentation in linux kernel (i.e. are there situations where L4 protocols are not fragment friendly)? How is this handled in other common OSes like windows? In general how frequently IP packets are fragmented?

  Read the article

• Unity in C# for Platform Specific Implementations

  - by DxCK

  My program has heavy interaction with the operating system through Win32API functions. now i want to migrate my program to run under Mono under Linux (No wine), and this requires different implementations to the interaction with the operating system. I started designing a code that can have different implementation for difference platform and is extensible for new future platforms. public interface ISomeInterface { void SomePlatformSpecificOperation(); } [PlatformSpecific(PlatformID.Unix)] public class SomeImplementation : ISomeInterface { #region ISomeInterface Members public void SomePlatformSpecificOperation() { Console.WriteLine("From SomeImplementation"); } #endregion } public class PlatformSpecificAttribute : Attribute { private PlatformID _platform; public PlatformSpecificAttribute(PlatformID platform) { _platform = platform; } public PlatformID Platform { get { return _platform; } } } public static class PlatformSpecificUtils { public static IEnumerable<Type> GetImplementationTypes<T>() { foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies()) { foreach (Type type in assembly.GetTypes()) { if (typeof(T).IsAssignableFrom(type) && type != typeof(T) && IsPlatformMatch(type)) { yield return type; } } } } private static bool IsPlatformMatch(Type type) { return GetPlatforms(type).Any(platform => platform == Environment.OSVersion.Platform); } private static IEnumerable<PlatformID> GetPlatforms(Type type) { return type.GetCustomAttributes(typeof(PlatformSpecificAttribute), false) .Select(obj => ((PlatformSpecificAttribute)obj).Platform); } } class Program { static void Main(string[] args) { Type first = PlatformSpecificUtils.GetImplementationTypes<ISomeInterface>().FirstOrDefault(); } } I see two problems with this design: I can't force the implementations of ISomeInterface to have a PlatformSpecificAttribute. Multiple implementations can be marked with the same PlatformID, and i dont know witch to use in the Main. Using the first one is ummm ugly. How to solve those problems? Can you suggest another design?

  Read the article

• C# how to calculate hashcode from an object reference.

  - by Wayne

  Folks, here's a thorny problem for you! A part of the TickZoom system must collect instances of every type of object into a Dictionary< type. It is imperative that their equality and hash code be based on the instance of the object which means reference equality instead of value equality. The challenge is that some of the objects in the system have overridden Equals() and GetHashCode() for use as value equality and their internal values will change over time. That means that their Equals and GetHashCode are useless. How to solve this generically rather than intrusively? So far, We created a struct to wrap each object called ObjectHandle for hashing into the Dictionary. As you see below we implemented Equals() but the problem of how to calculate a hash code remains. public struct ObjectHandle : IEquatable<ObjectHandle>{ public object Object; public bool Equals(ObjectHandle other) { return object.ReferenceEquals(this.Object,other.Object); } } See? There is the method object.ReferenceEquals() which will compare reference equality without regard for any overridden Equals() implementation in the object. Now, how to calculate a matching GetHashCode() by only considering the reference without concern for any overridden GetHashCode() method? Ahh, I hope this give you an interesting puzzle. We're stuck over here. Sincerely, Wayne

  Read the article

• creating matrix with probabilities

  - by John Chan

  Hi all, I want to generate a matrix of NxN to test some code that I have where each row contains floats as the elements and has to add up to 1 (i.e. a row with a set of probabilities). Where it gets tricky is that I want to make sure that randomly some of the elements should be 0 (in fact most of the elements should be 0 except for some random ones to be the probabilities). I need the probabilities to be 1/m where m is the number of elements that are not 0 within a single row. I tried to think of ways to output this, but essentially I would need this stored in a C++ array. So even if I output to a file I would still have the issue of not having it in array as I need it. At the end of it all I need that array because I want to generate a Market Matrix file. I found an implementation in C++ to take an array and convert it to the market matrix file, so this is what I am basing my findings on. My input for the rest of the code takes in this market matrix file so I need that to be the primary form of output. The language does not matter, I just want to generate the file at the end (I found a way mmwrite and mmread in python as well) Please help, I am stuck and not really sure how to implement this.

  Read the article

• Fastest Java way to remove the first/top line of a file (like a stack)

  - by christangrant

  I am trying to improve an external sort implementation in java. I have a bunch of BufferedReader objects open for temporary files. I repeatedly remove the top line from each of these files. This pushes the limits of the Java's Heap. I would like a more scalable method of doing this without loosing speed because of a bunch of constructor calls. One solution is to only open files when they are needed, then read the first line and then delete it. But I am afraid that this will be significantly slower. So using Java libraries what is the most efficient method of doing this. --Edit-- For external sort, the usual method is to break a large file up into several chunk files. Sort each of the chunks. And then treat the sorted files like buffers, pop the top item from each file, the smallest of all those is the global minimum. Then continue until for all items. http://en.wikipedia.org/wiki/External_sorting My temporary files (buffers) are basically BufferedReader objects. The operations performed on these files are the same as stack/queue operations (peek and pop, no push needed). I am trying to make these peek and pop operations more efficient. This is because using many BufferedReader objects takes up too much space.

  Read the article

• Mercurial repository usage with binary files for building setup files

  - by Ryan

  I have an existing Mercurial repository for a C++ application in a small corporate environment. I asked a co-worker to add the setup script to the repository and he added all of the dependency binaries, PDFs, and executable to the repository under an Install directory. I dislike having the binaries and dependencies in the same repository, but I'd like recommendations on best practices. Here are the options I am considering: Create a separate repository for the Installer and related files Create a subrepository for the Installer and related files Use a (yet to be identified) build dependency manager I am concerned with using a subrepository with Mercurial based on what I've read so far and the (apparently) incomplete implementation. I would like to get a project dependency system, e.g. Ivy, but I don't know all of the options and haven't had time yet to try out any options. I thought I'd use TortoiseHg as a basis, and it does not have the TortoiseHg binaries in the repository although it does have some binaries such as kdiff3.exe. Instead it uses setup.py to clone multiple repositories and build the apps. This seems reasonable for OSS, but not so much for corporate environments. Recommendations?

  Read the article

< Previous Page | 255 256 257 258 259 260 261 262 263 264 265 266  | Next Page >