我有一个使用GCDAsyncSocket作为网络接口库的Cocoa实时视频程序。播放视频帧时有明显的缓慢。例如,视频上的时间几乎是正常情况下的两倍。通过检查性能,我发现GCDAsyncSocket的readDataToLength方法调用得太稀少。下面是日志,时间戳:GCDAsyncSocket读取数据问题
2012-05-16 11:18:27.054 DVRLibDemo[1181:903] readDataToLength
2012-05-16 11:18:27.256 DVRLibDemo[1181:903] readDataToLength
2012-05-16 11:18:27.285 DVRLibDemo[1181:903] readDataToLength
2012-05-16 11:18:27.452 DVRLibDemo[1181:903] readDataToLength
2012-05-16 11:18:27.475 DVRLibDemo[1181:903] readDataToLength
2012-05-16 11:18:27.697 DVRLibDemo[1181:903] readDataToLength
2012-05-16 11:18:27.726 DVRLibDemo[1181:903] readDataToLength
2012-05-16 11:18:27.856 DVRLibDemo[1181:903] readDataToLength
我创建套接字时设置了单独的委托调度队列,但它并没有太大的帮助。消息有一个固定的头,我首先读取头,然后读取有效载荷。
- (void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
DVRConnection *conn = [self getConnectionWithSocket:sock];
//DebugLogInfo(@"Receive raw data: %@ for connection: %d", data, conn.tag);
if (conn != nil && conn.connected)
{
if (tag == TAG_XM_MESSAGE_HEADER)
{
uint32_t bodyLen = [_parser parseMessageHeader:data];
[sock readDataToLength:bodyLen withTimeout:-1 tag:TAG_XM_MESSAGE_PAYLOAD];
}
else if (tag == TAG_XM_MESSAGE_PAYLOAD)
{
[_parser parseMessage:data forConnection:conn device:self];
[sock readDataToLength:XM_MESSAGE_HEADER_LENGTH withTimeout:-1 tag:TAG_XM_MESSAGE_HEADER];
}
}
}
没有人有任何想法,以提高从套接字读取数据的速度?谢谢!
感谢Hlung。刚发现我忘了更新这个问题的状态。最后它变成了我的应用程序代码中的一个错误,与GCDAsyncSocket无关。 Wrt UDP,我连接的DVR只打开了TCP连接,我明白制造商更喜欢TCP到UDP,因为TCP的可靠性。 – cs2k