UDPEcho.h

/*
    File:       UDPEcho.h
 
    Contains:   A class that implements a UDP echo protocol client and server.
 
    Written by: DTS
 
    Copyright:  Copyright (c) 2010-12 Apple Inc. All Rights Reserved.
 
    Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc.
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*/
 
#import <Foundation/Foundation.h>
 
#if TARGET_OS_EMBEDDED || TARGET_IPHONE_SIMULATOR
    #import <CFNetwork/CFNetwork.h>
#else
    #import <CoreServices/CoreServices.h>
#endif
 
@protocol UDPEchoDelegate;
 
@interface UDPEcho : NSObject
 
- (id)init;
 
- (void)startServerOnPort:(NSUInteger)port;
    // Starts an echo server on the specified port.  Will call the 
    // -echo:didStartWithAddress: delegate method on success and the 
    // -echo:didStopWithError: on failure.  After that, the various 
    // 'data' delegate methods may be called.
 
- (void)startConnectedToHostName:(NSString *)hostName port:(NSUInteger)port;
    // Starts a client targetting the specified host and port.  
    // Will call -echo:didStartWithAddress: delegate method on success and 
    // the -echo:didStopWithError: on failure.  At that point you can call 
    // -sendData: to send data to the server and the various 'data' delegate 
    // methods may be called.
 
- (void)sendData:(NSData *)data;
    // On the client, sends the specified data to the server.  The 
    // -echo:didSendData:toAddress: or -echo:didFailToSendData:toAddress:error: 
    // delegate method will be called to indicate the success or failure 
    // of the send, and the -echo:didReceiveData:fromAddress: delegate method 
    // will be called if a response is received.
 
- (void)stop;
    // Will stop the object, preventing any future network operations or delegate 
    // method calls until the next start call.
 
@property (nonatomic, weak,   readwrite) id<UDPEchoDelegate>    delegate;
@property (nonatomic, assign, readonly, getter=isServer) BOOL   server;
@property (nonatomic, copy,   readonly ) NSString *             hostName;       // valid in client mode
@property (nonatomic, copy,   readonly ) NSData *               hostAddress;    // valid in client mode after successful start
@property (nonatomic, assign, readonly ) NSUInteger             port;           // valid in client and server mode
 
@end
 
@protocol UDPEchoDelegate <NSObject>
 
@optional
 
// In all cases an address is an NSData containing some form of (struct sockaddr), 
// specifically a (struct sockaddr_in) or (struct sockaddr_in6).
 
- (void)echo:(UDPEcho *)echo didReceiveData:(NSData *)data fromAddress:(NSData *)addr;
    // Called after successfully receiving data.  On a server object this data will 
    // automatically be echoed back to the sender.
    //
    // assert(echo != nil);
    // assert(data != nil);
    // assert(addr != nil);
    
- (void)echo:(UDPEcho *)echo didReceiveError:(NSError *)error;
    // Called after a failure to receive data.
    //
    // assert(echo != nil);
    // assert(error != nil);
    
- (void)echo:(UDPEcho *)echo didSendData:(NSData *)data toAddress:(NSData *)addr;
    // Called after successfully sending data.  On the server side this is typically 
    // the result of an echo.
    //
    // assert(echo != nil);
    // assert(data != nil);
    // assert(addr != nil);
    
- (void)echo:(UDPEcho *)echo didFailToSendData:(NSData *)data toAddress:(NSData *)addr error:(NSError *)error;
    // Called after a failure to send data.
    //
    // assert(echo != nil);
    // assert(data != nil);
    // assert(addr != nil);
    // assert(error != nil);
 
- (void)echo:(UDPEcho *)echo didStartWithAddress:(NSData *)address;
    // Called after the object has successfully started up.  On the client addresses 
    // is the list of addresses associated with the host name passed to 
    // -startConnectedToHostName:port:.  On the server, this is the local address 
    // to which the server is bound.
    //
    // assert(echo != nil);
    // assert(address != nil);
    
- (void)echo:(UDPEcho *)echo didStopWithError:(NSError *)error;
    // Called after the object stops spontaneously (that is, after some sort of failure, 
    // but now after a call to -stop).
    //
    // assert(echo != nil);
    // assert(error != nil);
 
@end