Search Results

Search found 11639 results on 466 pages for 'numerical methods'.

Page 155/466 | < Previous Page | 151 152 153 154 155 156 157 158 159 160 161 162  | Next Page >

• Manual Linq to SQL entity framework mapping

  - by kprobst

  I've been playing with the O/R designer in VS and I was wondering if someone could shed come light on this. I'm used to OR mappers that are largely manual (homegrown and e.g., NHibernate). I don't mind encoding the entity classes myself, since they don't change all that often to begin with, and I have this irrational fear of designers and auto generated code as it is. I have noticed that the generated entity classes contain a lot of boilerplate extensibility methods, e.g. On[Property]Changed() and so on where [Property] is a mapped member of the class. These are placed in the setters of the property accessors. I assume it's OK if I don't include these when I do my hand coding, correct? They would be nice if I needed some sort of interception pattern but that's certainly not the case. I guess I just need to know if any of those methods are required by the entity framework to keep track of changes to the mapping types in order for things to work when updating the database. Thanks!

  Read the article

• Best practice on structuring asynchronous mailers (using Sidekiq)

  - by gbdev

  Just wondering what's the best way to go about structuring asynchronous mailers in my Rails app (using Sidekiq)? I have one ActionMailer class with multiple methods/emails... notifier.rb: class Notifier < ActionMailer::Base default from: "\"Company Name\" <[email protected]>" default_url_options[:host] = Rails.env.production? ? 'domain.com' : 'localhost:5000' def welcome_email(user) @user = user mail to: @user.email, subject: "Thanks for signing up!" end ... def password_reset(user) @user = user @edit_password_reset_url = edit_password_reset_url(user.perishable_token) mail to: @user.email, subject: "Password Reset" end end Then for example, the password_reset mail is sent in my User model by doing... user.rb: def deliver_password_reset_instructions! reset_perishable_token! NotifierWorker.perform_async(self) end notifier_worker.rb: class NotifierWorker include Sidekiq::Worker sidekiq_options queue: "mail" def perform(user) Notifier.password_reset(user).deliver end end So I guess I'm wondering a couple things here... Is it possible to define many "perform" actions in one single worker? By doing so I could keep things simple (one notifier/mail worker) as I have it and send many different emails through it. Or should I create many workers? One for each mailer (e.g. WelcomeEmailWorker, PasswordResetWorker, etc) and just assign them all to use the same "mail" queue with Sidekiq. I know it works as it is, but should I break out each of those mail methods (welcome_email, password_reset, etc) into individually mailer classes or is it ok to have them all under one class like Notifier? Really appreciate any advice here. Thanks!

  Read the article

• Get class constant names in php?

  - by user151841

  I have a php class with some class constants that indicate the status of an instance. When I'm using the class, after I run some methods on it, I do some checks to make sure that the status is what I expect it to be. For instance, after calling some methods, I expect the status to be MEANINGFUL_STATUS_NAME. $objInstance->method1(); $objInstance->method2(); if ( $objInstance->status !== class::MEANINGFUL_STATUS_NAME ) { throw new Exception("Status is wrong, should not be " . class::MEANINGFUL_STATUS_NAME . "."); } However, this gives me the exception message "Status is wrong, should not be 2" when what I really want to see is "Status is wrong, should not be MEANINGFUL_STATUS_NAME" So I've lost the meaningfulness of the constant name. I was thinking of making an 'translation table' array, so I can take the constant values and translate them back into their name, but this seems cumbersome. How should I translate this back, so I get an error message that gives me a better idea of what went wrong?

  Read the article

• implementing the generic interface

  - by user845405

  Could any one help me on implementing the generic interface for this class. I want to be able to use the below Cache class methods through an interface. Thank you for the help!. public class CacheStore { private Dictionary<string, object> _cache; private object _sync; public CacheStore() { _cache = new Dictionary<string, object>(); _sync = new object(); } public bool Exists<T>(string key) where T : class { Type type = typeof(T); lock (_sync) { return _cache.ContainsKey(type.Name + key); } } public bool Exists<T>() where T : class { Type type = typeof(T); lock (_sync) { return _cache.ContainsKey(type.Name); } } public T Get<T>(string key) where T : class { Type type = typeof(T); lock (_sync) { if (_cache.ContainsKey(key + type.Name) == false) throw new ApplicationException(String.Format("An object with key '{0}' does not exists", key)); lock (_sync) { return (T)_cache[key + type.Name]; } } } public void Add<T>(string key, T value) { Type type = typeof(T); if (value.GetType() != type) throw new ApplicationException(String.Format("The type of value passed to cache {0} does not match the cache type {1} for key {2}", value.GetType().FullName, type.FullName, key)); lock (_sync) { if (_cache.ContainsKey(key + type.Name)) throw new ApplicationException(String.Format("An object with key '{0}' already exists", key)); lock (_sync) { _cache.Add(key + type.Name, value); } } } } Could any one help me on implementing the generic interface for this class. I want to be able to use the below Cache class methods through an interface.

  Read the article

• How to show useful error messages from a database error callback in Phonegap?

  - by Magnus Smith

  Using Phonegap you can set a function to be called back if the whole database transaction or the individual SQL statement errors. I'd like to know how to get more information about the error. I have one generic error-handling function, and lots of different SELECTs or INSERTs that may trigger it. How can I tell which one was at fault? It is not always obvious from the error message. My code so far is... function get_rows(tx) { tx.executeSql("SELECT * FROM Blah", [], lovely_success, statement_error); } function add_row(tx) { tx.executeSql("INSERT INTO Blah (1, 2, 3)", [], carry_on, statement_error); } function statement_error(tx, error) { alert(error.code + ' / ' + error.message); } From various examples I see the error callback will be passed a transaction object and an error object. I read that .code can have the following values: UNKNOWN_ERR = 0 DATABASE_ERR = 1 VERSION_ERR = 2 TOO_LARGE_ERR = 3 QUOTA_ERR = 4 SYNTAX_ERR = 5 CONSTRAINT_ERR = 6 TIMEOUT_ERR = 7 Are there any other properties/methods of the error object? What are the properties/methods of the transaction object at this point? I can't seem to find a good online reference for this. Certainly not on the Phonegap website!

  Read the article

• How to differentiate between method and function in a decorator?

  - by defnull

  I want to write a decorator that acts differently depending on whether it is applied to a function or to a method. def some_decorator(func): if the_magic_happens_here(func): # <---- Point of interest print 'Yay, found a method ^_^ (unbound jet)' else: print 'Meh, just an ordinary function :/' return func class MyClass(object): @some_decorator def method(self): pass @some_decorator def function(): pass I tried inspect.ismethod(), inspect.ismethoddescriptor() and inspect.isfunction() but no luck. The problem is that a method actually is neither a bound nor an unbound method but an ordinary function as long as it is accessed from within the class body. What I really want to do is to delay the actions of the decorator to the point the class is actually instantiated because I need the methods to be callable in their instance scope. For this, I want to mark methods with an attribute and later search for these attributes when the .__new__() method of MyClass is called. The classes for which this decorator should work are required to inherit from a class that is under my control. You can use that fact for your solution. In the case of a normal function the delay is not necessary and the decorator should take action immediately. That is why I wand to differentiate these two cases.

  Read the article

• Calling a network State check from other activities

  - by Laurent

  I realize this question has been answered before but couldn't find an answer that deals with my specific case. I want to create a class called "InternetConnectionChecks" that will handle checking a network state and http timeouts. I'll call the methods twice in the app (once at the beginning to get data from a server, and once at the end to send user orders to the server). For good form I'd like to put all these methods in a single class rather than copy/paste at different points in my code. To check the network state, I'm using ConnectivityManager; thing is, getSystemService requires a class that extends Activity. package arbuckle.app; import android.app.Activity; import android.app.Service; import android.content.Context; import android.net.ConnectivityManager; import android.net.NetworkInfo; public class InternetConnectionChecks extends Activity { public boolean isNetworkAvailable(){ ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo(); if ((activeNetworkInfo != null)&&(activeNetworkInfo.isConnected())){ return true; }else{ return false; } } } QUESTION: if I call the method isNetworkAvailable from another activity, am I: - going to hit up serious errors. - violating good coding form? *If this isn't the right way to do things, can you point me in the right direction to set up a separate class I can call on to check internet connection? Thanks everyone!

  Read the article

• Why aren't my threads start at the same time? Java

  - by Ada

  Hi, I have variable number of threads which are used for parallel downloading. I used this, for(int i = 0; i< sth; i++){ thrList.add(new myThread (parameters)); thrList.get(i).start(); thrList.get(i).join(); } I don't know why but they wait for each other to complete. When using threads, I am supposed get mixed print outs, since right then there are several threads running that code. However, when I print them out, they are always in order and one thread waits for the previous one to finish first. I only want them to join the main thread, not wait for each other. I noticed that when I measured time while downloading in parallel. How can I fix this? Why are they doing it in order? In my .java, there is MyThread class with run and there is Downloader class with static methods and variables. Would they be the cause of this? The static methods and variables? How can I fix this problem?

  Read the article

• Looking for an appropriate design pattern

  - by user1066015

  I have a game that tracks user stats after every match, such as how far they travelled, how many times they attacked, how far they fell, etc, and my current implementations looks somewhat as follows (simplified version): Class Player{ int id; public Player(){ int id = Math.random()*100000; PlayerData.players.put(id,new PlayerData()); } public void jump(){ //Logic to make the user jump //... //call the playerManager PlayerManager.jump(this); } public void attack(Player target){ //logic to attack the player //... //call the player manager PlayerManager.attack(this,target); } } Class PlayerData{ public static HashMap<int, PlayerData> players = new HashMap<int,PlayerData>(); int id; int timesJumped; int timesAttacked; } public void incrementJumped(){ timesJumped++; } public void incrementAttacked(){ timesAttacked++; } } Class PlayerManager{ public static void jump(Player player){ players.get(player.getId()).incrementJumped(); } public void incrementAttacked(Player player, Player target){ players.get(player.getId()).incrementAttacked(); } } So I have a PlayerData class which holds all of the statistics, and brings it out of the player class because it isn't part of the player logic. Then I have PlayerManager, which would be on the server, and that controls the interactions between players (a lot of the logic that does that is excluded so I could keep this simple). I put the calls to the PlayerData class in the Manager class because sometimes you have to do certain checks between players, for instance if the attack actually hits, then you increment "attackHits". The main problem (in my opinion, correct me if I'm wrong) is that this is not very extensible. I will have to touch the PlayerData class if I want to keep track of a new stat, by adding methods and fields, and then I have to potentially add more methods to my PlayerManager, so it isn't very modulized. If there is an improvement to this that you would recommend, I would be very appreciative. Thanks.

  Read the article

• Setting the type of a field in a superclass from a subclass (Java)

  - by Ibolit

  Hi. I am writing a project on Google App Engine, within it I have a number of abstract classes that I hope I will be able to use in my future projects, and a number of concrete classes inheriting from them. Among other abstract classes I have an abstract servlet that does user management, and I hava an abstract user. The AbstractUser has all the necessary fields and methods for storing it in the datastore and telling whether the user is registered with my service or not. It does not implement any project specific functionality. The abstract servlet that manages users, refers only to the methods declared in the AbstractUser class, which allows it to generate links for logging in, logging out and registering (for unregistered users). In order to implement the project-specific user functionality I need to subclass the Abstract user. The servlets I use in my project are all indirect descendants from that abstract user management servlet, and the user is a protected field in it, so the descendant servlets can use it as their own field. However, whenever i want to access any project specific method of the concrete user, i need to cast it to that type. i.e. (abstract user managing servlet) ... AbstractUser user = getUser(); ... abstract protected AbstractUser getUser(); (project-specific abstract servlet) @Override protected AbstractUser getUser() { return MyUserFactory.getUser(); } any other project specific servlet: int a = ((ConcreteUser) user).getA(); Well, what i'd like to do is to somehow make the type of “user” in the superclass depend on something in the project-specific abstract class. Is it at all possible? And i don't want to move all the user-management stuff into a project-specific layer, for i would like to have it for my future projects already written :) Thank you for your help.

  Read the article

• Generic Func<> as parameter to base method

  - by WestDiscGolf

  I might be losing the plot, but I hope someone can point me in the right direction. What am I trying to do? I'm trying to write some base methods which take Func< and Action so that these methods handle all of the exception handling etc. so its not repeated all over the place but allow the derived classes to specify what actions it wants to execute. So far this is the base class. public abstract class ServiceBase<T> { protected T Settings { get; set; } protected ServiceBase(T setting) { Settings = setting; } public void ExecAction(Action action) { try { action(); } catch (Exception exception) { throw new Exception(exception.Message); } } public TResult ExecFunc<T1, T2, T3, TResult>(Func<T1, T2, T3, TResult> function) { try { /* what goes here?! */ } catch (Exception exception) { throw new Exception(exception.Message); } } } I want to execute an Action in the following way in the derived class (this seems to work): public void Delete(string application, string key) { ExecAction(() => Settings.Delete(application, key)); } And I want to execute a Func in a similar way in the derived class but for the life of me I can't seem to workout what to put in the base class. I want to be able to call it in the following way (if possible): public object Get(string application, string key, int? expiration) { return ExecFunc(() => Settings.Get(application, key, expiration)); } Am I thinking too crazy or is this possible? Thanks in advance for all the help.

  Read the article

• How to delay execution of a method in c#?

  - by Pandiya Chendur

  I have this if condition, if (sendSMS(Convert.ToInt32(DLComportNo.SelectedItem.Text), TxtDriMob.Text, TxtCliDet.Text) && sendSMS(Convert.ToInt32(DLComportNo.SelectedItem.Text), TxtCliMob.Text, TxtDriDet.Text)) { // I am inserting details to my db } and my sendSMS method looks like this, private bool sendSMS(int portNo, string mobNo, string details) { try { SerialPort SerialPort1 = new SerialPort(); SerialPort1.PortName = "COM" + portNo.ToString(); SerialPort1.BaudRate = 9600; SerialPort1.Parity = Parity.None; SerialPort1.DataBits = 8; SerialPort1.StopBits = StopBits.One; SerialPort1.RtsEnable = true; SerialPort1.DtrEnable = true; SerialPort1.Encoding.GetEncoder(); SerialPort1.ReceivedBytesThreshold = 1; SerialPort1.NewLine = Environment.NewLine; SerialPort1.Open(); SerialPort1.Write("AT" + SerialPort1.NewLine); Sleep(500); SerialPort1.Write("AT+CMGF=1" + SerialPort1.NewLine); Sleep(500); SerialPort1.Write("AT+CMGS=" + (char)34 + mobNo + (char)34 + SerialPort1.NewLine); Sleep(1000); SerialPort1.Write(details + (char)26); Sleep(2000); SerialPort1.Close(); } catch { } return true; } What happens is when i use break point in my sendSMS i get my output (ie) both the methods get executed and messages are sent properly... But when i removed my breakpoint both the methods in the if statement are executed but message from the first method is sent and not from the second method.... Any suggestion?

  Read the article

• Obj-C Sending Messages Between Classes

  - by user544359

  I'm a newbie in iPhone Programming. I'm trying to send a message from one view controller to another. The idea is that viewControllerA takes information from the user and sends it to viewControllerB. viewControllerB is then supposed to display the information in a label. viewControllerA.h #import <UIKit/UIKit.h> @interface viewControllerA : UIViewController { int num; } -(IBAction)do; @end viewControllerA.m #import "viewControllerA.h" #import "viewControllerB.h" @implementation viewControllerA - (IBAction)do { //initializing int for example num = 2; viewControllerB *viewB = [[viewControllerB alloc] init]; [viewB display:num]; [viewB release]; //viewA is presented as a ModalViewController, so it dismisses itself to return to the //original view, i know it is not efficient [self dismissModalViewControllerAnimated:YES]; } - (void)dealloc { [super dealloc]; } @end viewControllerB.h #import <UIKit/UIKit.h> @interface viewControllerB : UIViewController { IBOutlet UILabel *label; } - (IBAction)openA; - (void)display:(NSInteger)myNum; @end viewControllerB.m #import "viewControllerB.h" #import "viewControllerA.h" @implementation viewControllerB - (IBAction)openA { //presents viewControllerA when a button is pressed viewControllerA *viewA = [[viewControllerA alloc] init]; [self presentModalViewController:viewA animated:YES]; } - (void)display:(NSInteger)myNum { NSLog(@"YES"); [label setText:[NSString stringWithFormat:@"%d", myNum]]; } @end YES is logged successfully, but the label's text does not change. I have made sure that all of my connections in Interface Builder are correct, in fact there are other (IBAction) methods in my program that change the text of this very label, and all of those other methods work perfectly... Any ideas, guys? You don't need to give me a full solution, any bits of information will help. Thanks.

  Read the article

• STLifying C++ classes

  - by shambulator

  I'm trying to write a class which contains several std::vectors as data members, and provides a subset of vector's interface to access them: class Mesh { public: private: std::vector<Vector3> positions; std::vector<Vector3> normals; // Several other members along the same lines }; The main thing you can do with a mesh is add positions, normals and other stuff to it. In order to allow an STL-like way of accessing a Mesh (add from arrays, other containers, etc.), I'm toying with the idea of adding methods like this: public: template<class InIter> void AddNormals(InIter first, InIter last); Problem is, from what I understand of templates, these methods will have to be defined in the header file (seems to make sense; without a concrete iterator type, the compiler doesn't know how to generate object code for the obvious implementation of this method). Is this actually a problem? My gut reaction is not to go around sticking huge chunks of code in header files, but my C++ is a little rusty with not much STL experience outside toy examples, and I'm not sure what "acceptable" C++ coding practice is on this. Is there a better way to expose this functionality while retaining an STL-like generic programming flavour? One way would be something like this: (end list) class RestrictedVector<T> { public: RestrictedVector(std::vector<T> wrapped) : wrapped(wrapped) {} template <class InIter> void Add(InIter first, InIter last) { std::copy(first, last, std::back_insert_iterator(wrapped)); } private: std::vector<T> wrapped; }; and then expose instances of these on Mesh instead, but that's starting to reek a little of overengineering :P Any advice is greatly appreciated!

  Read the article

• what's a good technique for building and running many similar unit tests?

  - by jcollum

  I have a test setup where I have many very similar unit tests that I need to run. For example, there are about 40 stored procedures that need to be checked for existence in the target environment. However I'd like all the tests to be grouped by their business unit. So there'd be 40 instances of a very similar TestMethod in 40 separate classes. Kinda lame. One other thing: each group of tests need to be in their own solution. So Business Unit A will have a solution called Tests.BusinessUnitA. I'm thinking that I can set this all up by passing a configuration object (with the name of the stored proc to check, among other things) to a TestRunner class. The problem is that I'm losing the atomicity of my unit tests. I wouldn't be able to run just one of the tests, I'd have to run all the tests in the TestRunner class. This is what the code looks like at this time. Sure, it's nice and compact, but if Test 8 fails, I have no way of running just Test 8. TestRunner runner = new TestRunner(config, this.TestContext); var runnerType = typeof(TestRunner); var methods = runnerType.GetMethods() .Where(x => x.GetCustomAttributes(typeof(TestMethodAttribute), false) .Count() > 0).ToArray(); foreach (var method in methods) { method.Invoke(runner, null); } So I'm looking for suggestions for making a group of unit tests that take in a configuration object but won't require me to generate many many TestMethods. This looks like it might require code-generation, but I'd like to solve it without that.

  Read the article

• iPhone app developed with SDK 4.2, requires backward compatibility with iOS 3.1.3 .. easy way?

  - by mrd3650

  I have built an iPhone app with SDK 4.2 however I know also want to make it compatible with iOS 3.1.3. First step was to set the Deployment Target to 3.1.3. It runs fine on the 3.2 Simulator but the app crashes at times since I'm using some methods which are not available in this early SDK. So my qestion is, is there a straight forward way to locate the offending methods/classes I'm using in my project which are not available in 3.1.3 ? (without manually going through each method call and consult with the docs for the SDK availability?) Thanks. UPDATE: I have executed the app on 3.1.3 and attempted to manually test each execution path with the hope of locating all exceptions. This was completed with some level of success. However, what if the application is huge? and there are lots of execution paths? There must be some tool for this scenario. Any thoughts are much appreciated.

  Read the article

• PHP shell_exec() - Run directly, or perform a cron (bash/php) and include MySQL layer?

  - by Jimbo

  Sorry if the title is vague - I wasn't quite sure how to word it! What I'm Doing I'm running a Linux command to output data into a variable, parse the data, and output it as an array. Array values will be displayed on a page using PHP, and this PHP page output is requested via AJAX every 10 seconds so, in effect, the data will be retrieved and displayed/updated every 10 seconds. There could be as many as 10,000 characters being parsed on every request, although this is usually much lower. Alternative Idea I want to know if there is a better* alternative method of retrieving this data every 10 seconds, as multiple users (<10) will be having this command executed automatically for them. A cronjob running on the server could execute either bash or php (which is faster?) to grab the data and store it in a MySQL database. Then, any AJAX calls to the PHP output would return values in the MySQL database rather than making a direct call to execute server code every 10 seconds. Why? I know there are security concerns with running execs directly from PHP, and (I hope this isn't micro-optimisation) I'm worried about CPU usage on the server. The server is running a sempron processor. Yes, they do still exist. Having this only execute when the user is on the page (idea #1) means that the server isn't running code that doesn't need to be run. However, is this slow and insecure? Just in case the type of linux command may be of assistance in determining it's efficiency: shell_exec("transmission-remote $host:$port --auth $username:$password -l"); I'm hoping that there are differences in efficiency and level of security with the two methods I have outlined above, and that this isn't just micro-micro-optimisation. If there are alternative methods that are better*, I'd love to learn about these! :)

  Read the article

• Mapping many-to-many association table with extra column(s)

  - by user635524

  My database contains 3 tables: User and Service entities have many-to-many relationship and are joined with the SERVICE_USER table as follows: USERS - SERVICE_USER - SERVICES SERVICE_USER table contains additional BLOCKED column. What is the best way to perform such a mapping? These are my Entity classes @Entity @Table(name = "USERS") public class User implements java.io.Serializable { private String userid; private String email; @Id @Column(name = "USERID", unique = true, nullable = false,) public String getUserid() { return this.userid; } .... some get/set methods } @Entity @Table(name = "SERVICES") public class CmsService implements java.io.Serializable { private String serviceCode; @Id @Column(name = "SERVICE_CODE", unique = true, nullable = false, length = 100) public String getServiceCode() { return this.serviceCode; } .... some additional fields and get/set methods } I followed this example http://giannigar.wordpress.com/2009/09/04/m ... using-jpa/ Here is some test code: User user = new User(); user.setEmail("e2"); user.setUserid("ui2"); user.setPassword("p2"); CmsService service= new CmsService("cd2","name2"); List<UserService> userServiceList = new ArrayList<UserService>(); UserService userService = new UserService(); userService.setService(service); userService.setUser(user); userService.setBlocked(true); service.getUserServices().add(userService); userDAO.save(user); The problem is that hibernate persists User object and UserService one. No success with the CmsService object I tried to use EAGER fetch - no progress Is it possible to achieve the behaviour I'm expecting with the mapping provided above? Maybe there is some more elegant way of mapping many to many join table with additional column?

  Read the article

• Hiding instantiated templates in shared library created with g++

  - by jchl

  I have a file that contains the following: #include <map> class A {}; void doSomething() { std::map<int, A> m; } When compiled into a shared library with g++, the library contains dynamic symbols for all the methods of std::map<int, A>. Since A is private to this file, there is no possibility that std::map will be instantiated in any other shared library with the same parameters, so I'd like to make the template instantiation hidden (for some of the reasons described in this document). I thought I should be able to do this by adding an explicit instantiation of the template class and marking it as hidden, like so: #include <map> class A {}; template class __attribute__((visibility ("hidden"))) std::map<int, A>; void doSomething() { std::map<int, A> m; } However, this has no effect: the symbols are still all exported. I even tried compiling with -fvisibility=hidden, but this also has no effect on the visibility of the methods of std::map<int, A> (although it does hide doSomething). The document I linked to above describes the use of export maps to restrict visibility, but that seems very tedious. Is there a way to do what I want in g++ (other than using export maps)? If so, what is it? If not, is there a good reason why these symbols must always be exported, or is this just a omission in g++?

  Read the article

• How to correctly pass a float from C# to C++ (dll)

  - by RavelT

  I'm getting huge differences when I pass a float from C# to C++. I'm passing a dynamic float wich changes over time. With a debuger I get this: c++ lonVel -0.036019072 float c# lonVel -0.029392920 float I did set my MSVC++2010 floating point model to /fp:fast wich should be the standard in .NET if I'm not mistaken, but this didnt help. Now I cant give out the code but I can show a fraction of it. From C# side it looks like this: namespace Example { public class Wheel { public bool loging = true; #region Members public IntPtr nativeWheelObject; #endregion Members public Wheel() { this.nativeWheelObject = Sim.Dll_Wheel_Add(); return; } #region Wrapper methods public void SetVelocity(float lonRoadVelocity,float latRoadVelocity){Sim.Dll_Wheel_SetVelocity(this.nativeWheelObject,lonRoadVelocity,latRoadVelocity);} #endregion Wrapper methods } internal class Sim { #region PInvokes [DllImport(pluginName, CallingConvention=CallingConvention.Cdecl)] public static extern void Dll_Wheel_SetVelocity(IntPtr wheel,float lonRoadVelocity,float latRoadVelocity); #endregion PInvokes } } And in C++ side @ exportFunctions.cpp: EXPORT_API void Dll_Wheel_SetVelocity(CarWheel* wheel,float lonRoadVelocity,float latRoadVelocity){ wheel->SetVelocity(lonRoadVelocity,latRoadVelocity);} So any sugestions on what I should do in order to get 1:1 results or atleast 99% correct results.

  Read the article

• Java: GatheringByteChannel advantages?

  - by Jason S

  I'm wondering when the GatheringByteChannel's write methods (taking in an array of ByteBuffers) have advantages over the "regular" WritableByteChannel write methods. I tried a test where I could use the regular vs. the gathering write method on a FileChannel, with approx 400KB/sec total in ByteBuffers of between 23-27 bytes in length in both cases. Gathering writes used an array of 64. The regular method used up approx 12% of my CPU, and the gathering method used up approx 16% of my CPU (worse than the regular method!) This tells me it's NOT useful to use gathering writes on a FileChannel around this range of operating parameters. Why would this be the case, and when would you ever use GatheringByteChannel? (on network I/O?) Relevant differences here: public void log(Queue<Packet> packets) throws IOException { if (this.gather) { int Nbuf = 64; ByteBuffer[] bbufs = new ByteBuffer[Nbuf]; int i = 0; Packet p; while ((p = packets.poll()) != null) { bbufs[i++] = p.getBuffer(); if (i == Nbuf) { this.fc.write(bbufs); i = 0; } } if (i > 0) { this.fc.write(bbufs, 0, i); } } else { Packet p; while ((p = packets.poll()) != null) { this.fc.write(p.getBuffer()); } } }

  Read the article

• .NET List Thread-Safe Implementation Suggestion needed

  - by Bamboo

  .Net List class isn't thread safe. I hope to achieve the minimal lock needed and yet still fulfilling the requirement such that as for reading, phantom record is allowed, and for writing, they must be thread-safe so there won't be any lost updates. So I have something like public static List<string> list = new List<string>(); In Methods that have **List.Add**/**List.Remove** , I always lock to assure thread safety lock (lockHelper) { list.Add(obj); or list.Remove(obj); } In Methods that requires **List Reading** I don't care about phantom record so I go ahead to read without any locking. In this case. Return a bool by checking whether a string had been added. if (list.Count() != 0) { return list.Contains("some string") } All I did was locking write accesses, and allow read accesses to go through without any locking. Is my thread safety idea valid? I understand there is List size expansion. Will it be ok? My guess is that when a List is expanding, it may uses a temp. list. This is ok becasue the temp list size will always have a boundary, and .Net class is well implemented, ie. there shouldn't be any indexOutOfBound or circular reference problems when reading was caught in updates.

  Read the article

• Reference properteries declared in a protocol and implemented in the anonymous category?

  - by Heath Borders

  I have the following protocol: @protocol MyProtocol @property (nonatomic, retain) NSObject *myProtocolProperty; -(void) myProtocolMethod; @end and I have the following class: @interface MyClass : NSObject { } @end I have a class extension declared, I have to redeclare my protocol properties here or else I can't implement them with the rest of my class. @interface()<MyProtocol> @property (nonatomic, retain) NSObject *myExtensionProperty; /* * This redeclaration is required or my @synthesize myProtocolProperty fails */ @property (nonatomic, retain) NSObject *myProtocolProperty; - (void) myExtensionMethod; @end @implementation MyClass @synthesize myProtocolProperty = _myProtocolProperty; @synthesize myExtensionProperty = _myExtensionProperty; - (void) myProtocolMethod { } - (void) myExtensionMethod { } @end In a consumer method, I can call my protocol methods and properties just fine. Calling my extension methods and properties produces a warning and an error respectively. - (void) consumeMyClassWithMyProtocol: (MyClass<MyProtocol> *) myClassWithMyProtocol { myClassWithMyProtocol.myProtocolProperty; // works, yay! [myClassWithMyProtocol myProtocolMethod]; // works, yay! myClassWithMyProtocol.myExtensionProperty; // compiler error, yay! [myClassWithMyProtocol myExtensionMethod]; // compiler warning, yay! } Is there any way I can avoid redeclaring the properties in MyProtocol within my class extension in order to implement MyProtocol privately?

  Read the article

• interface abstract in php real world scenario

  - by jason

  The goal is to learn whether to use abstract or interface or both... I'm designing a program which allows a user to de-duplicate all images but in the process rather then I just build classes I'd like to build a set of libraries that will allow me to re-use the code for other possible future purposes. In doing so I would like to learn interface vs abstract and was hoping someone could give me input into using either. Here is what the current program will do: recursive scan directory for all files determine file type is image type compare md5 checksum against all other files found and only keep the ones which are not duplicates Store total duplicates found at the end and display size taken up Copy files that are not duplicates into folder by date example Year, Month folder with filename is file creation date. While I could just create a bunch of classes I'd like to start learning more on interfaces and abstraction in php. So if I take the scan directory class as the first example I have several methods... ScanForFiles($path) FindMD5Checksum() FindAllImageTypes() getFileList() The scanForFiles could be public to allow anyone to access it and it stores in an object the entire directory list of files found and many details about them. example extension, size, filename, path, etc... The FindMD5Checksum runs against the fileList object created from scanForFiles and adds the md5 if needed. The FindAllImageTypes runs against the fileList object as well and adds if they are image types. The findmd5checksum and findallimagetypes are optionally run methods because the user might not intend to run these all the time or at all. The getFileList returns the fileList object itself. While I have a working copy I've revamped it a few times trying to figure out whether I need to go with an interface or abstract or both. I'd like to know how an expert OO developer would design it and why?

  Read the article

• (Java) Is there a type of object that can handle anything from primitives to arrays?

  - by Michael

  I'm pretty new to Java, so I'm hoping one of you guys knows how to do this. I'm having the user specify both the type and value of arguments, in any XML-like way, to be passed to methods that are external to my application. Example: javac myAppsName externalJavaClass methodofExternalClass [parameters] Of course, to find the proper method, we have to have the proper parameter types as the method may be overloaded and that's the only way to tell the difference between the different versions. Parameters are currently formatted in this manner: (type)value(/type), e.g. (int)71(/int) (string)This is my string that I'm passing as a parameter!(/string) I parse them, getting the constructor for whatever type is indicated, then execute that constructor by running its method, newInstance(<String value>), loading the new instance into an Object. This works fine and dandy, but as we all know, some methods take arrays, or even multi-dimensional arrays. I could handle the argument formatting like so: (array)(array)(int)0(/int)(int)1(/int)(/array)(array)(int)2(/int)(int)3(/int)(/array)(/array)... or perhaps even better... {{(int)0(/int)(int)1(/int)}{(int)2(/int)(int)3(/int)}}. The question is, how can this be implemented? Do I have to start wrapping everything in an Object[] array so I can handle primitives, etc. as argObj[0], but load an array as I normally would? (Unfortunately, I would have to make it an Object[][] array if I wanted to support two-dimensional arrays. This implementation wouldn't be very pretty.)

  Read the article

< Previous Page | 151 152 153 154 155 156 157 158 159 160 161 162  | Next Page >