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• FF extension: saving a value in preferences and retrieving in the js file

  - by encryptor

  I am making an extension which should take a link as the user input only once. Then the entire extension keeps using that link on various functions in the JS file. When the user changes it, the value accessed by the js file also changes accordingly. I am using the following but it does not work for me var pref_manager = Components.classes["@mozilla.org/preferencesservice;1"].getService(Components.interfaces.nsIPrefService) function setInstance(){ if (pref_manager.prefHasUserValue("myvar")) { instance = pref_manager.getString("myvar"); alert(instance); } if(instance == null){ instance = prompt("Please enter webcenter host and port"); // Setting the value pref_manager.setString("myvar", instance); } } instance is the global variable in which i take the user input. The alert (instance) does not show up, which means there is some problem by the way i am saving the pref or extracting it. Can someone please help me with this. I have never worked with preferences before. so even if there are minor problems i might not be able to figure out.

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• Importing into a Exported object with MEF

  - by Nathan W

  I'm sorry if this question has already been asked 100 times, but I'm really struggling to get it to work. Say I have have three projects. Core.dll Has common interfaces Shell.exe Loads all modules in assembly folder. References Core.dll ModuleA.dll Exports Name, Version of module. References Core.dll Shell.exe has a [Export] that contains an single instance of a third party application that I need to inject into all loaded modules. So far the code that I have in Shell.exe is: static void Main(string[] args) { ThirdPartyApp map = new ThirdPartyApp(); var ad = new AssemblyCatalog(Assembly.GetExecutingAssembly()); var dircatalog = new DirectoryCatalog("."); var a = new AggregateCatalog(dircatalog, ad); // Not to sure what to do here. } class Test { [Export(typeof(ThirdPartyApp))] public ThirdPartyApp Instance { get; set; } [Import(typeof(IModule))] public IModule Module { get; set; } } I need to create a instance of Test, and load Instance with map from the Main method then load the Module from ModuleA.dll that is in the executing directory then [Import] Instance into the loaded module. In ModuleA I have a class like this: [Export(IModule)] class Module : IModule { [Import(ThirdPartyApp)] public ThirdPartyApp Instance {get;set;} } I know I'm half way there I just don't know how to put it all together, mainly with loading up test with a instance of map from Main. Could anyone help me with this.

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• (nested) user controls within a mvp pattern causing sporadic problems

  - by LLEA

  hi everyone, I have a serious problem with nested user controls (UCs) in WinForms while trying to implement the mvp pattern (passive view). The project consists of one model (designed as a singleton) and a set of different presenters with corresponding view interfaces. To avoid one huge view interface and therefore an overloaded main UI, I decided to make use of a set of different UCs. Each UC has one view interface and one presenter that can access the model. But there are nested UCs: meaning that one specialised UC implements sort of a basic UC. The main UI just represents a container for all those UCs. So far, so good (if not, please ask)?! There are two problems that I am facing now (but I guess both are of the same origin): From time to time it is not possible anymore to load the UCs and test them within the Visual Studio 2008 User Control Test Container. The error message just says that a project with an output type of class library cannot be started directly etc. I can "handle" that by unloading all UC projects and reloading them afterwards. (I guess the references to all mvp components and other UCs are then updated). Assuming that the implementation of my mvp pattern is okay and all those UCs are testable within the VS Test Container at a certain time - there is the biggest problem still left: I am not able to add any UC (even the basic and unnested ones) to a simple Form (UI). The error message: error message.jpg Could it be that my basic UC causes all these Problems?! It consists of two simple ComboBoxes and implements a basic presenter and basic view interface. Whenever I add this UC to a different UC the VS designer adds two references to the public getter methods of the UC as resources. I then manually remove those resources from the resx-file and commend the corresponding lines in the designer file. thx in advance

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• How To Create a Flexible Plug-In Architecture?

  - by justkt

  A repeating theme in my development work has been the use of or creation of an in-house plug-in architecture. I've seen it approached many ways - configuration files (XML, .conf, and so on), inheritance frameworks, database information, libraries, and others. In my experience: A database isn't a great place to store your configuration information, especially co-mingled with data Attempting this with an inheritance hierarchy requires knowledge about the plug-ins to be coded in, meaning the plug-in architecture isn't all that dynamic Configuration files work well for providing simple information, but can't handle more complex behaviors Libraries seem to work well, but the one-way dependencies have to be carefully created. As I seek to learn from the various architectures I've worked with, I'm also looking to the community for suggestions. How have you implemented a solid plug-in architecture? What was your worst failure (or the worst failure you've seen)? What would you do if you were going to implement a new plug-in architecture? What SDK or open source project that you've worked with has the best example of a good architecture? A few examples I've been finding on my own: Perl's Module::Plugable An SO question with a list for Java (including Sever Provider Interfaces) An SO question for C++ pointing to a Dr. Dobbs article These examples seem to play to various language strengths. Is a good plugin architecture necessarily tied to the language? Is it best to use tools to create a plugin architecture, or to do it on one's own following models?

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• Conditional column values in NSTableView?

  - by velocityb0y

  I have an NSTableView that binds via an NSArrayController to an NSMutableArray. What's in the array are derived classes; the first few columns of the table are bound to properties that exist on the base class. That all works fine. Where I'm running into problem is a column that should only be populated if the row maps to one specific subclass. The property that column is meant to display only exists in that subclass, since it makes no sense in terms of the base class. The user will know, from the first two columns, why the third column's cell is populated/editable or not. The binding on the third column's value is on arrangedObjects, with a model path of something like "foo.name" where foo is the property on the subclass. However, this doesn't work, as the other subclasses in the hierarchy are not key-value compliant for foo. It seems like my only choice is to have foo be a property on the base class so everybody responds to it, but this clutters up the interfaces of the model objects. Has anyone come up with a clean design for this situation? It can't be uncommon (I'm a relative newcomer to Cocoa and I'm just learning the ins and outs of bindings.)

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• c++ Design pattern for CoW, inherited classes, and variable shared data?

  - by krunk

  I've designed a copy-on-write base class. The class holds the default set of data needed by all children in a shared data model/CoW model. The derived classes also have data that only pertains to them, but should be CoW between other instances of that derived class. I'm looking for a clean way to implement this. If I had a base class FooInterface with shared data FooDataPrivate and a derived object FooDerived. I could create a FooDerivedDataPrivate. The underlying data structure would not effect the exposed getters/setters API, so it's not about how a user interfaces with the objects. I'm just wondering if this is a typical MO for such cases or if there's a better/cleaner way? What peeks my interest, is I see the potential of inheritance between the the private data classes. E.g. FooDerivedDataPrivate : public FooDataPrivate, but I'm not seeing a way to take advantage of that polymorphism in my derived classes. class FooDataPrivate { public: Ref ref; // atomic reference counting object int a; int b; int c; }; class FooInterface { public: // constructors and such // .... // methods are implemented to be copy on write. void setA(int val); void setB(int val); void setC(int val); // copy constructors, destructors, etc. all CoW friendly private: FooDataPrivate *data; }; class FooDerived : public FooInterface { public: FooDerived() : FooInterface() {} private: // need more shared data for FooDerived // this is the ???, how is this best done cleanly? };

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• Free utility which runs in Linux to create a UML class diagram from Java source files

  - by DeletedAccount

  I prefer to jot down UML-diagrams on paper and then implement them using Java. It would be nice to have a utility which could create UML-diagrams for me which I may share on-line and include in the digital documentation. In other words: I want to create UML diagrams from Java source code. The utility must be able to: Run in Linux. Handle Generics, i.e show List<Foo correctly in parameters and return type. Show class inheritance and interface implementations. It's nice if the utility is able to: Run in Windows and Mac OS X. Display enums in some nice manner. Generate output in a diagram format which I may modify using some other utility. Run from the command line. Restrict the UML generation to a set of packages which I may specify. Handle classes/interfaces which are not part of my source code. It could include the first class/interface which is external in the UML diagram. Perhaps in another color to indicate it being a library/framework created by someone else. Focuses on this task and doesn't try to solve the whole issue of documentation.

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• how to multithread on a python server

  - by user3732790

  HELP please i have this code import socket from threading import * import time HOST = '' # Symbolic name meaning all available interfaces PORT = 8888 # Arbitrary non-privileged port s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print ('Socket created') s.bind((HOST, PORT)) print ('Socket bind complete') s.listen(10) print ('Socket now listening') def listen(conn): odata = "" end = 'end' while end == 'end': data = conn.recv(1024) if data != odata: odata = data print(data) if data == b'end': end = "" print("conection ended") conn.close() while True: time.sleep(1) conn, addr = s.accept() print ('Connected with ' + addr[0] + ':' + str(addr[1])) Thread.start_new_thread(listen,(conn)) and i would like it so that when ever a person comes onto the server it has its own thread. but i can't get it to work please someone help me. :_( here is the error code: Socket created Socket bind complete Socket now listening Connected with 127.0.0.1:61475 Traceback (most recent call last): File "C:\Users\Myles\Desktop\test recever - Copy.py", line 29, in <module> Thread.start_new_thread(listen,(conn)) AttributeError: type object 'Thread' has no attribute 'start_new_thread' i am on python version 3.4.0 and here is the users code: import socket #for sockets import time s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print('Socket Created') host = 'localhost' port = 8888 remote_ip = socket.gethostbyname( host ) print('Ip address of ' + host + ' is ' + remote_ip) #Connect to remote server s.connect((remote_ip , port)) print ('Socket Connected to ' + host + ' on ip ' + remote_ip) while True: message = input("> ") #Set the whole string s.send(message.encode('utf-8')) print ('Message send successfully') data = s.recv(1024) print(data) s.close

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• 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

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• template specialization of a auto_ptr<T>

  - by Chris Kaminski

  Maybe I'm overcomplicating things, but then again, I do sort of like clean interfaces. Let's say I want a specialization of auto_ptr for an fstream - I want a default fstream for the generic case, but allow a replacement pointer? tempate <> class auto_ptr<fstream> static fstream myfStream; fstream* ptr; public: auto_ptr() { // set ptr to &myfStream; } reset(fstream* newPtr) { // free old ptr if not the static one. ptr = newPtr }; } Would you consider something different or more elegant? And how would you keep something like the above from propagating outside this particular compilation unit? [The actual template is a boost::scoped_ptr.] EDIT: It's a contrived example. Ignore the fstream - it's about providing a default instance of object for an auto_ptr. I may not want to provide a specialized instance, but would like to keep the auto_ptr semantics for this static default object. class UserClass { public: auto_ptr<fstream> ptr; UserClass() { } } I may not provide an dynamic object at construction time - I still want it to have a meaningful default. Since I'm not looking at ownership-transfer semantics, it really shouldn't matter that my pointer class is pointing to a statically allocated object, no?

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• DDD and Entity Base, Model using multiple identity types

  - by Thomas

  I have a model that looks like this: public interface IEntity { int Id { get; set; } } Then the idea is to have my entities inherit from this interface: public class User : IEntity { public int Id { get; set; } } However, one of my entities actually has a Guid as an identifier. public class UserSession { public Guid Id { get; set; } } I really would like all my entities inheriting from the same interface but that would force me to add an integer based identity column to the UserSession which is unnecessary since Guid is the identity, but it would keep the domain model nice since all entities would inherit from the same base. What options do I have in this scenario? Can I have two base interfaces, one for int and one for Guid? Should I add an identity column into the UserSession entity although it is unnecessary? I need the Guid so I can't just get rid of it and replace it with and integer. Any thoughts on best practices?

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• Compiling a Windows C++ program in g++

  - by Phenom

  I'm trying to compile a Windows C++ program in g++. This is what I get. /usr/include/c++/4.4/backward/backward_warning.h:28:2: warning: #warning This file includes at least one deprecated or antiquated header which may be removed without further notice at a future date. Please use a non-deprecated interface with equivalent functionality instead. For a listing of replacement headers and interfaces, consult the file backward_warning.h. To disable this warning use -Wno-deprecated. btree.cpp:1204: error: ‘_TCHAR’ has not been declared btree.cpp: In function ‘int _tmain(int, int**)’: btree.cpp:1218: error: ‘__int64’ was not declared in this scope btree.cpp:1218: error: expected ‘;’ before ‘frequency’ btree.cpp:1220: error: ‘LARGE_INTEGER’ was not declared in this scope btree.cpp:1220: error: expected primary-expression before ‘)’ token btree.cpp:1220: error: ‘frequency’ was not declared in this scope btree.cpp:1220: error: ‘QueryPerformanceFrequency’ was not declared in this scope btree.cpp:1262: error: expected primary-expression before ‘)’ token btree.cpp:1262: error: ‘start’ was not declared in this scope btree.cpp:1262: error: ‘QueryPerformanceCounter’ was not declared in this scope btree.cpp:1264: error: name lookup of ‘i’ changed for ISO ‘for’ scoping btree.cpp:1264: note: (if you use ‘-fpermissive’ G++ will accept your code) btree.cpp:1304: error: expected primary-expression before ‘)’ token btree.cpp:1304: error: ‘end’ was not declared in this scope btree.cpp:1306: error: ‘total’ was not declared in this scope btree.cpp:1316: error: ‘getchar’ was not declared in this scope The first thing I noticed is that there are these variable types called _TCHAR, _int64, and LARGE_INTEGER, which is probably a Windows thing. What can these be changed to so that they will work in g++? Also, if there's anything else in here that you know can be converted to g++, that would be helpful. I got the code from here: http://touc.org/btree.html

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• how do use Ninject with class libraries I am developing?

  - by Greg

  Hi, If I am working on a class library how do I make use of Ninject here? Ie from the internal class library point of view and also from the client code? For example: should the class library have it's own IOC set up, or should it always assume the client code will supply? if no (ie it's upto the client to have the IOC in place) then where is the mapping data stored here'. Is this mapping of the class library's functionality to be places in the client? have a reusable library that is available, that uses interfaces with classes that use the getInstance concept to create concrete classes for you to use, then in this case would that make sense on the client side to use the IOC container to create instances of these classes? Or is that really applying a double layer of abstraction? Q2 Or in the cases where I'm building the reusable library myself and want the client to use an IOC container, then in my reusable library would I then dispense with any overhead of having factories or "getInstance" methods to instantiate the classes in the client? (i.e. as the IOC container would do this no?)

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• OOP, Interface Design and Encapsulation

  - by Mau

  C# project, but it could be applied to any OO languages. 3 interfaces interacting: public interface IPublicData {} public /* internal */ interface IInternalDataProducer { string GetData(); } public interface IPublicWorker { IPublicData DoWork(); IInternalDataProducer GetInternalProducer(); } public class Engine { Engine(IPublicWorker worker) {} IPublicData Run() { DoSomethingWith(worker.GetInternalProducer().GetData()); return worker.DoWork(); } } Clearly Engine is parametric in the actual worker that does the job. A further source of parametrization is how we produce the 'internal data' via IInternalDataProducer. This implementation requires IInternalDataProducer to be public because it's part of the declaration of the public interface IPublicWorker. However, I'd like it to be internal since it's only used by the engine. A solution is make the IPublicWorker produce the internal data itself, but that's not very elegant since there's only a couple of ways of producing it (while there are many more worker implementations), therefore it's nice to delegate to a couple of separate concrete classes. Moreover, the IInternalDataProducer is used in more places inside the engine, so it's good for the engine to pass around the actual object. I'm looking for elegant ideas/patterns. Cheers :-)

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• Android NDK import-module / code reuse

  - by Graeme

  Morning! I've created a small NDK project which allows dynamic serialisation of objects between Java and C++ through JNI. The logic works like this: Bean - JavaCInterface.Java - JavaCInterface.cpp - JavaCInterface.java - Bean The problem is I want to use this functionality in other projects. I separated out the test code from the project and created a "Tester" project. The tester project sends a Java object through to C++ which then echo's it back to the Java layer. I thought linking would be pretty simple - ("Simple" in terms of NDK/JNI is usually a day of frustration) I added the JNIBridge project as a source project and including the following lines to Android.mk: NDK_MODULE_PATH=.../JNIBridge/jni/" JNIBridge/jni/JavaCInterface/Android.mk: ... include $(BUILD_STATIC_LIBRARY) JNITester/jni/Android.mk: ... include $(BUILD_SHARED_LIBRARY) $(call import-module, JavaCInterface) This all works fine. The C++ files which rely on headers from JavaCInterface module work fine. Also the Java classes can happily use interfaces from JNIBridge project. All the linking is happy. Unfortunately JavaCInterface.java which contains the native method calls cannot see the JNI method located in the static library. (Logically they are in the same project but both are imported into the project where you wish to use them through the above mechanism). My current solutions are are follows. I'm hoping someone can suggest something that will preserve the modular nature of what I'm trying to achieve: My current solution would be to include the JavaCInterface cpp files in the calling project like so: LOCAL_SRC_FILES := FunctionTable.cpp $(PATH_TO_SHARED_PROJECT)/JavaCInterface.cpp But I'd rather not do this as it would lead to me needing to update each depending project if I changed the JavaCInterface architecture. I could create a new set of JNI method signatures in each local project which then link to the imported modules. Again, this binds the implementations too tightly.

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• MEF GetExports<T, TMetaDataView> returning nothing with AllowMultiple = True

  - by sohum

  I don't understand MEF very well, so hopefully this is a simple fix of how I think it works. I'm trying to use MEF to get some information about a class and how it should be used. I'm using the Metadata options to try to achieve this. My interfaces and attribute looks like this: public interface IMyInterface { } public interface IMyInterfaceInfo { Type SomeProperty1 { get; } double SomeProperty2 { get; } string SomeProperty3 { get; } } [MetadataAttribute] [AttributeUsage(AttributeTargets.Class, AllowMultiple = true)] public class ExportMyInterfaceAttribute : ExportAttribute, IMyInterfaceInfo { public ExportMyInterfaceAttribute(Type someProperty1, double someProperty2, string someProperty3) : base(typeof(IMyInterface)) { SomeProperty1 = someProperty1; SomeProperty2 = someProperty2; SomeProperty3 = someProperty3; } public Type SomeProperty1 { get; set; } public double SomeProperty2 { get; set; } public string SomeProperty3 { get; set; } } The class that is decorated with the attribute looks like this: [ExportMyInterface(typeof(string), 0.1, "whoo data!")] [ExportMyInterface(typeof(int), 0.4, "asdfasdf!!")] public class DecoratedClass : IMyInterface { } The method that is trying to use the import looks like this: private void SomeFunction() { // CompositionContainer is an instance of CompositionContainer var myExports = CompositionContainer.GetExports<IMyInterface, IMyInterfaceInfo>(); } In my case myExports is always empty. In my CompositionContainer, I have a Part in my catalog that has two ExportDefinitions, both with the following ContractName: "MyNamespace.IMyInterface". The Metadata is also loaded correctly per my exports. If I remove the AllowMultiple setter and only include one exported attribute, the myExports variable now has the single export with its loaded metadata. What am I doing wrong?

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• Programming exercises in Java inheritance for intern

  - by Tenner

  I work for a small software development team, working primarily in Java, for a very large company. Our new intern showed up sight-unseen (not uncommon in my company). He has some C++ experience but no Java. Worse, he's never worked with inheritance in C++. Our code has a great deal of abstraction and a heavy reliance on inheritance. We need to get him up to speed as quickly as possible. Of course the rest of the team is busy, and so we can't take the time out of our day to teach a one-student 200-level CS course. Instead, I'd like to give him an actual programming project to work on which highlights how classes, interfaces, method overrides, etc. work. I've had him look at Project Euler, but most of the solutions end up being procedural, and not object-oriented programs. Do any of you have any somewhat-straightforward (and relatively quick) projects which you would give to an intern in this situation? Or, any recent (or current) students have a school project they'd be willing to share? Anyone else had this experience?

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• Cant render a .avi file

  - by Manish

  Hi, This is my 3rd post regarding this issue of cropping a file into smaller (same format files) .Please some one help me with this.Here is my code : CoInitialize(NULL); //Create the FGM CoCreateInstance(CLSID_FilterGraph,NULL,CLSCTX_INPROC_SERVER,IID_IGraphBuilder,(void**)(&pGraphBuilder)); //Query the Interfaces pGraphBuilder->QueryInterface(IID_IMediaControl,(void**)&pMediaControl); pGraphBuilder->QueryInterface(IID_IMediaEvent,(void**)&pMediaEvent); pGraphBuilder->QueryInterface(IID_IMediaPosition,(void**)&pMediaPosition); //Adding a Filewriter before calling the renderfile IBaseFilter *pWriter=NULL; IFileSinkFilter *pSink=NULL; CoCreateInstance(CLSID_FileWriter,NULL,CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&pWriter)); pWriter->QueryInterface(IID_IFileSinkFilter,(void**)&pSink); pSink->SetFileName(OUTFILE,NULL); //Create a source filter IBaseFilter* pSource=NULL; HRESULT hr11=pGraphBuilder->AddSourceFilter(FILENAME,L"Source",&pSource); //Create a AVI mux IBaseFilter *pAVImux; CoCreateInstance(CLSID_AviDest,NULL,CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&pAVImux)); pGraphBuilder->AddFilter(pAVImux,L"AVI Mux"); pGraphBuilder->AddFilter(pWriter,L"File Writer"); //Connect Source and Mux IEnumPins* pEnum1=NULL; IPin* pPin1=NULL; IEnumPins *pEnum2=NULL; IPin *pPin2=NULL; pSource->EnumPins(&pEnum1); pEnum1->Next(1,&pPin1,NULL); HRESULT hr1=ConnectFilters(pGraphBuilder,pPin1,pAVImux); //Mux to Writer HRESULT hr4=ConnectFilters(pGraphBuilder,pAVImux,pWriter); //Render the input file HRESULT hr3=pGraphBuilder->RenderFile(FILENAME,NULL); //Set Display times pMediaPosition->put_CurrentPosition(0); pMediaPosition->put_StopTime(2); //Run the graph HRESULT hr=pMediaControl->Run(); On running no video is shown. All the hresults return S_OK .A .avi file( larger than original is created) and I cannot play that file.

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• Can't get KnownType to work with WCF

  - by Kelly Cline

  I have an interface and a class defined in separate assemblies, like this: namespace DataInterfaces { public interface IPerson { string Name { get; set; } } } namespace DataObjects { [DataContract] [KnownType( typeof( IPerson ) ) ] public class Person : IPerson { [DataMember] public string Name { get; set; } } } This is my Service Interface: public interface ICalculator { [OperationContract] IPerson GetPerson ( ); } When I update my Service Reference for my Client, I get this in the Reference.cs: public object GetPerson() { return base.Channel.GetPerson(); I was hoping that KnownType would give me IPerson instead of "object" here. I have also tried [KnownType( typeof( Person ) ) ] with the same result. I have control of both client and server, so I have my DataObjects (where Person is defined) and DataInterfaces (where IPerson is defined) assemblies in both places. Is there something obvious I am missing? I thought KnownType was the answer to being able to use interfaces with WCF. ----- FURTHER INFORMATION ----- I removed the KnownType from the Person class and added [ServiceKnownType( typeof( Person ) ) ] to my service interface, as suggested by Richard. The client-side proxy still looks the same, public object GetPerson() { return base.Channel.GetPerson(); , but now it doesn't blow up. The client just has an "object", though, so it has to cast it to IPerson before it is useful. var person = client.GetPerson ( ); Console.WriteLine ( ( ( IPerson ) person ).Name );

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• What database strategy to choose for a large web application

  - by Snoopy

  I have to rewrite a large database application, running on 32 servers. The hardware is up to date, each machine has two quad core Xeon and 32 GByte RAM. The database is multi-tenant, each customer has his own file, around 5 to 10 GByte each. I run around 50 databases on this hardware. The app is open to the web, so I have no control on the load. There are no really complex queries, so SQL is not required if there is a better solution. The databases get updated via FTP every day at midnight. The database is read-only. C# is my favourite language and I want to use ASP.NET MVC. I thought about the following options: Use two big SQL servers running SQL Server 2012 to serve the 32 servers with data. On the 32 servers running IIS hosting providing REST services. Denormalize the database and use Redis on each webserver. Use booksleeve as a Redis client. Use a combination of SQL Server and Redis Use SQL Server 2012 together with Hadoop Use Hadoop without SQL Server What is the best way for a read-only database, to get the best performance without loosing maintainability? Does Map-Reduce make sense at all in such a scenario? The reason for the rewrite is, the old app written in C++ with ISAM technology is too slow, the interfaces are old fashioned and not nice to use from an website, especially when using ajax. The app uses a relational datamodel with many tables, but it is possible to write one accerlerator table where all queries can be performed on, and all other information from the other tables are possible by a simple key lookup.

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• Why doesn't the Java Collections API include a Graph implementation?

  - by dvanaria

  I’m currently learning the Java Collections API and feel I have a good understanding of the basics, but I’ve never understood why this standard API doesn’t include a Graph implementation. The three base classes are easily understandable (List, Set, and Map) and all their implementations in the API are mostly straightforward and consistent. Considering how often graphs come up as a potential way to model a given problem, this just doesn’t make sense to me (it’s possible it does exist in the API and I’m not looking in the right place of course). Steve Yegge suggests in one of his blog posts that a programmer should consider graphs first when attacking a problem, and if the problem domain doesn’t fit naturally into this data structure, only then consider the alternative structures. My first guess is that there is no universal way to represent graphs, or that their interfaces may not be generic enough for an API implementation to be useful? But if you strip down a graph to its basic components (vertices and a set of edges that connect some or all of the vertices) and consider the ways that graphs are commonly constructed (methods like addVertex(v) and insertEdge(v1, v2)) it seems that a generic Graph implementation would be possible and useful. Thanks for helping me understand this better.

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• Are bad data issues that common?

  - by Water Cooler v2

  I've worked for clients that had a large number of distinct, small to mid-sized projects, each interacting with each other via properly defined interfaces to share data, but not reading and writing to the same database. Each had their own separate database, their own cache, their own file servers/system that they had dedicated access to, and so they never caused any problems. One of these clients is a mobile content vendor, so they're lucky in a way that they do not have to face the same problems that everyday business applications do. They can create all those separate compartments where their components happily live in isolation of the others. However, for many business applications, this is not possible. I've worked with a few clients, one of whose applications I am doing the production support for, where there are "bad data issues" on an hourly basis. Yeah, it's that crazy. Some data records from one of the instances (lower than production, of course) would have been run a couple of weeks ago, and caused some other user's data to get corrupted. And then, a data script will have to be written to fix this issue. And I've seen this happening so much with this client that I have to ask. I've seen this happening at a moderate rate with other clients, but this one just seems to be out of order. If you're working with business applications that share a large amount of data by reading and writing to/from the same database, are "bad data issues" that common in your environment?

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• What kind of library to use for display of graphical objects and right click context menus

  - by Gopal

  Hi all, Goal: To develop a web based NMS interface which displays a network topology (e.g., switches, routers, links, endhosts). Each node should be 'movable' (draggable to an appropriate place manually or their best location computed algorithmically). I should be able to zoom into the network graph (say if there are many clusters of nodes and I want to concentrate on a particular cluster of nodes). I should be able to right-click any node or link and get a context menu (e.g., 'show routing table', 'show interfaces', 'show bandwidth utilization graph' etc.). The data for this network topology will be fetched by making calls to an apache based webserver where the backend scripts in python will fetch the appropriate data and send it via JSON to the web client. Question: I am assuming that some sort of javascript library/framework will be most appropriate for this - jQuery, Dojo, Moo etc. [I've never used any of these before]. Which of these would be most recommended for this sort of thing. Which would be easiest to learn (say in a months time). Thanks for any tips.

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• NHibernate is not connecting to sql server.

  - by user177883

  When i set up a regular connection, it works, however when i try to use nhibernate, hibernate.cfg.xml, i m getting the following error. Message="A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)" Source=".Net SqlClient Data Provider" What would be the reason for this and how can i resolve it ? I doubt that it s a network or sql server configuration error. <?xml version="1.0" ?> <hibernate-configuration xmlns="urn:nhibernate-configuration-2.2" > <session-factory> <property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property> <property name="dialect">NHibernate.Dialect.MsSql2005Dialect</property> <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property> <property name="connection.connection_string">Server=(ServerName\DEV_ENV);Initial Catalog=dbName;User Id=SA;Password=PASS</property> <property name="proxyfactory.factory_class">NHibernate.ByteCode.LinFu.ProxyFactoryFactory, NHibernate.ByteCode.LinFu</property> </session-factory> </hibernate-configuration>

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• GNU C++ how to check when -std=c++0x is in effect?

  - by TerryP

  My system compiler (gcc42) works fine with the TR1 features that I want, but trying to support newer compiler versions other than the systems, trying to accessing TR1 headers an #error demanding the -std=c++0x option because of how it interfaces with library or some hub bub like that. /usr/local/lib/gcc45/include/c++/bits/c++0x_warning.h:31:2: error: #error This file requires compiler and library support for the upcoming ISO C++ standard, C++0x. This support is currently experimental, and must be enabled with the -std=c++0x or -std=gnu++0x compiler options. Having to supply an extra switch is no problem, to support GCC 4.4 and 4.5 under this system (FreeBSD), but obviously it changes the picture! Using my system compiler (g++ 4.2 default dialect): #include <tr1/foo> using std::tr1::foo; Using newer (4.5) versions of the compiler with -std=c++0x: #include <foo> using std::foo; Is there anyway using the pre processor, that I can tell if g++ is running with C++0x features enabled? Something like this is what I'm looking for: #ifdef __CXX0X_MODE__ #endif but I have not found anything in the manual or off the web. At this rate, I'm starting to think that life would just be easier, to use Boost as a dependency, and not worry about a new language standard arriving before TR4... hehe.

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