CocoaAsyncSocket 示例程序分析

CocoaAsyncSocket

Echo Server：

驗證：

kaishangdeMacBook-Air:~ Aaron$ telnet 127.0.0.1 8888
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Welcome to the AsyncSocket Echo Server
hello
hello


Echo server started on port 8888
Accepted client 127.0.0.1:54280
hello
are you okay

Code

EchoServer
初始化
socketQueue = dispatch_queue_create("socketQueue", NULL);
listenSocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:socketQueue];

等待建立連接
if(![listenSocket acceptOnPort:port error:&error])
{
	[self logError:FORMAT(@"Error starting server: %@", error)];
	return;
}

委託，剛建立連接
- (void)socket:(GCDAsyncSocket *)sock didAcceptNewSocket:(GCDAsyncSocket *)newSocket
{
	// This method is executed on the socketQueue (not the main thread)
	
	@synchronized(connectedSockets)
	{
		[connectedSockets addObject:newSocket];
	}
	
	NSString *host = [newSocket connectedHost];
	UInt16 port = [newSocket connectedPort];
	
	dispatch_async(dispatch_get_main_queue(), ^{
		@autoreleasepool {
		
			[self logInfo:FORMAT(@"Accepted client %@:%hu", host, port)];
		
		}
	});
	
	NSString *welcomeMsg = @"Welcome to the AsyncSocket Echo Server\r\n";
	NSData *welcomeData = [welcomeMsg dataUsingEncoding:NSUTF8StringEncoding];
	
	[newSocket writeData:welcomeData withTimeout:-1 tag:WELCOME_MSG];
	
	[newSocket readDataToData:[GCDAsyncSocket CRLFData] withTimeout:READ_TIMEOUT tag:0];
}

收到數據及echo處理
- (void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
	// This method is executed on the socketQueue (not the main thread)
	
	dispatch_async(dispatch_get_main_queue(), ^{
		@autoreleasepool {
		
			NSData *strData = [data subdataWithRange:NSMakeRange(0, [data length] - 2)];
			NSString *msg = [[NSString alloc] initWithData:strData encoding:NSUTF8StringEncoding];
			if (msg)
			{
				[self logMessage:msg];
			}
			else
			{
				[self logError:@"Error converting received data into UTF-8 String"];
			}
		
		}
	});
	
	// Echo message back to client
	[sock writeData:data withTimeout:-1 tag:ECHO_MSG];
}

超時
/**
 * This method is called if a read has timed out.
 * It allows us to optionally extend the timeout.
 * We use this method to issue a warning to the user prior to disconnecting them.
**/
- (NSTimeInterval)socket:(GCDAsyncSocket *)sock shouldTimeoutReadWithTag:(long)tag
                                                                 elapsed:(NSTimeInterval)elapsed
                                                               bytesDone:(NSUInteger)length
{
	if (elapsed <= READ_TIMEOUT)
	{
		NSString *warningMsg = @"Are you still there?\r\n";
		NSData *warningData = [warningMsg dataUsingEncoding:NSUTF8StringEncoding];
		
		[sock writeData:warningData withTimeout:-1 tag:WARNING_MSG];
		
		return READ_TIMEOUT_EXTENSION;
	}
	
	return 0.0;
}

庫源碼解析，待續
...