开源网络库 GCDAsyncSocket 笔记

GCDAsyncSocket 地址: https://github.com/robbiehanson/CocoaAsyncSocket/

使用方法:

创建:

asyncsocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];

这里我们让所有的回调执行都发生在主线程的queue里，当然我们可以传一个专用的queue.

连接 :

NSError *err = nil;
if (![asyncsocket connectToHost:@"deusty.com" onPort:80 error:&err]) // Asynchronous!
{
    //该方法异步，返回错误是因为 delegate没设置等
    NSLog(@"I goofed: %@", err);
}

　该方法会立刻返回,当成功连接上，delegate 的 socket:didConnectToHost:port: 方法会被调用.

- (void)socket:(GCDAsyncSocket *)sender didConnectToHost:(NSString *)host port:(UInt16)port
{
    NSLog(@"Cool, I'm connected! That was easy.");
}

有几种不同的连接方法,比如带超时的.。。。

虽然这个时候可能 socket 还没连接上，但是我们依然可以投递 读/写 请求:

[asyncSocket readDataToLength:LENGTH_HEADER withTimeout:-1 tag:TAG_HEADER];

这样读请求会自动进入了队列,当socket 连接上后,请求会自动出队被执行。(这里假设先读一个包头,再根据长度接收包体，这个读操作完成后 socket:didReadData:withTag: 会被调用)

当然我们可以投递多个读写操作而不必等待上一个完成.

[asyncSocket writeData:msgHeader withTimeout:-1 tag:TAG_HEADER];
[asyncSocket writeData:msgBody withTimeout:-1 tag:TAG_BODY];

上面的操作均为异步。下面为操作完成的委托方法:

read:

- (void)socket:(GCDAsyncSocket *)sender didReadData:(NSData *)data withTag:(long)tag
{
    if (tag == TAG_HEADER)
    {
        int bodyLength = [self parseHeader:data];
        [socket readDataToLength:bodyLength withTimeout:-1 tag:TAG_RESPONSE_BODY];
    }
    else if (tag == TAG_RESPONSE_BODY)
    {
        // Process the response
        [self handleResponseBody:data];

        // Start reading the next response
        [socket readDataToLength:headerLength withTimeout:-1 tag:TAG_FIXED_LENGTH_HEADER];
    }
}
//还有另一个读方法,
// [asyncSocket readDataToData:msgSeparator withTimeout:TIMEOUT_NONE tag:TAG_CAPABILITIES];
// 读当遇到一个指定的分隔符后操作返回。比如用作 http, 因为http 每个消息都会有一个@"\r\n\r\n" 结尾标志.

//如果想跟踪进度 socket: didReadPartialDataOfLength: tag: 用这个

write:

- (void)socket:(GCDAsyncSocket *)sock didWriteDataWithTag:(long)tag
{
    if (tag ==TAG_HEADER) 
　　　　NSLog(@"TAG_HEADER request sent"); 

　　else if (tag ==TAG_BODY) 
　　　　NSLog(@"TAG_BODY request sent");

}

断开释放一个连接实例

[asyncSocket setDelegate:nil delegateQueue:NULL];
[asyncSocket disconnect];
[asyncSocket release];

　　

相关的delegate 方法(回调)

socket: didConnectToHost: port:

socket: didReadData: withTag:
socket: didReadPartialDataOfLength: tag:
socket: shouldTimeoutReadWithTag: elapsed: bytesDone:

socket: didWriteDataWithTag:
socket: didWritePartialDataOfLength: tag:
socket: shouldTimeoutWriteWithTag: elapsed: bytesDone:

socketDidSecure:

socket: didAcceptNewSocket:

newSocketQueueForConnectionFromAddress: onSocket:

socketDidCloseReadStream:

socketDidDisconnect: withError: