Redis源码系列29：客户与服务器之间的网络交互源码readQueryFromClient

处理函数是：readQueryFromClient

nread = read(fd, buf, REDIS_QUERYBUF_LEN);
    if (nread == -1) 
	{
        if (errno == EAGAIN) 
		{
            nread = 0;
        } 
		else 
       	{
            redisLog(REDIS_DEBUG, "Reading from client: %s",strerror(errno));
            freeClient(c);
            return;
        }
    } 
	else if (nread == 0) 
	{
        redisLog(REDIS_DEBUG, "Client closed connection");
        freeClient(c);
        return;
    }
    if (nread) 
	{
        c->querybuf = sdscatlen(c->querybuf, buf, nread);
        c->lastinteraction = time(NULL);
    } 
	else 
	{
        return;
    }