SRS学习笔记12-SRSSOUCE类分析3

Posted 2020-09-22 燕十三

int SrsPublishEdge::initialize(SrsSource* source, SrsRequest* req)
{
    int ret = ERROR_SUCCESS;

    if ((ret = forwarder->initialize(source, this, req)) != ERROR_SUCCESS) {
        return ret;
    }
    
    return ret;
}

bool SrsPublishEdge::can_publish()
{
    return state != SrsEdgeStatePublish;
}

int SrsPublishEdge::on_client_publish()
{
    int ret = ERROR_SUCCESS;
    
    // error when not init state.
    if (state != SrsEdgeStateInit) {
        ret = ERROR_RTMP_EDGE_PUBLISH_STATE;
        srs_error("invalid state for client to publish stream on edge. "
            "state=%d, ret=%d", state, ret);
        return ret;
    }
    
    // @see https://github.com/ossrs/srs/issues/180
    // to avoid multiple publish the same stream on the same edge,
    // directly enter the publish stage.
    if (true) {
        SrsEdgeState pstate = state;
        state = SrsEdgeStatePublish;
        srs_trace("edge change from %d to state %d (push).", pstate, state);
    }
    
    // start to forward stream to origin.
    ret = forwarder->start();
    
    // @see https://github.com/ossrs/srs/issues/180
    // when failed, revert to init
    if (ret != ERROR_SUCCESS) {
        SrsEdgeState pstate = state;
        state = SrsEdgeStateInit;
        srs_trace("edge revert from %d to state %d (push). ret=%d", pstate, state, ret);
    }
    
    return ret;
}

SrsPublishEdge::on_client_publish这个函数在encoder 向 edge 推流是会调用这个函数,
用来启动farwarder,在 encoder 和 origin 之间转发 rtmp message.

这一篇分析 SrsRtmpConn::process_publish_message函数

对SrsSouce类的几个处理函数的代码

1. SrsSource::on_edge_proxy_publish

int SrsSource::on_edge_proxy_publish(SrsCommonMessage* msg)
{
    return publish_edge->on_proxy_publish(msg);
}

如果是edge,直接调用SrsPublishEdge类的on_proxy_publish方法,将msg转发到origin

int SrsPublishEdge::on_proxy_publish(SrsCommonMessage* msg)
{
    return forwarder->proxy(msg);
}

调用 SrsEdgeForwarder类的proxy函数

 

int SrsEdgeForwarder::proxy(SrsCommonMessage* msg)
{
    int ret = ERROR_SUCCESS;
    
    if ((ret = send_error_code) != ERROR_SUCCESS) {
        srs_error("publish edge proxy thread send error, ret=%d", ret);
        return ret;
    }
    
    // the msg is auto free by source,
    // so we just ignore, or copy then send it.
    if (msg->size <= 0
        || msg->header.is_set_chunk_size()
        || msg->header.is_window_ackledgement_size()
        || msg->header.is_ackledgement()
    ) {
        return ret;
    }
    
    SrsSharedPtrMessage copy;
    if ((ret = copy.create(msg)) != ERROR_SUCCESS) {
        srs_error("initialize the msg failed. ret=%d", ret);
        return ret;
    }
    srs_verbose("initialize shared ptr msg success.");
    
    copy.stream_id = stream_id;
    if ((ret = queue->enqueue(copy.copy())) != ERROR_SUCCESS) {
        srs_error("enqueue edge publish msg failed. ret=%d", ret);
    }
    
    return ret;
}

 

int SrsEdgeForwarder::proxy(SrsCommonMessage* msg)函数
用来将从 encoder接收的 rtmp msg 保存在 queue中

int SrsEdgeForwarder::start()
{
    int ret = ERROR_SUCCESS;
    
    send_error_code = ERROR_SUCCESS;
    
    std::string ep_server, ep_port;
    if ((ret = connect_server(ep_server, ep_port)) != ERROR_SUCCESS) {
        return ret;
    }
    srs_assert(client);

    client->set_recv_timeout(SRS_CONSTS_RTMP_RECV_TIMEOUT_US);
    client->set_send_timeout(SRS_CONSTS_RTMP_SEND_TIMEOUT_US);

    SrsRequest* req = _req;
    
    if ((ret = client->handshake()) != ERROR_SUCCESS) {
        srs_error("handshake with server failed. ret=%d", ret);
        return ret;
    }
    if ((ret = connect_app(ep_server, ep_port)) != ERROR_SUCCESS) {
        srs_error("connect with server failed. ret=%d", ret);
        return ret;
    }
    if ((ret = client->create_stream(stream_id)) != ERROR_SUCCESS) {
        srs_error("connect with server failed, stream_id=%d. ret=%d", stream_id, ret);
        return ret;
    }
    
    if ((ret = client->publish(req->stream, stream_id)) != ERROR_SUCCESS) {
        srs_error("publish failed, stream=%s, stream_id=%d. ret=%d", 
            req->stream.c_str(), stream_id, ret);
        return ret;
    }
    
    return pthread->start();
}

 

int SrsEdgeForwarder::start()函数

在encoder 向 edge推流是调用

作用是用 SrsRtmpClient类连接到 origin

SrsEdgeForwarder包含

SrsReusableThread2类

#define SYS_MAX_EDGE_SEND_MSGS 128
int SrsEdgeForwarder::cycle()
{
    int ret = ERROR_SUCCESS;
    
    client->set_recv_timeout(SRS_CONSTS_RTMP_PULSE_TIMEOUT_US);
    
    SrsPithyPrint* pprint = SrsPithyPrint::create_edge();
    SrsAutoFree(SrsPithyPrint, pprint);
    
    SrsMessageArray msgs(SYS_MAX_EDGE_SEND_MSGS);

    while (!pthread->interrupted()) {
        if (send_error_code != ERROR_SUCCESS) {
            st_usleep(SRS_EDGE_FORWARDER_ERROR_US);
            continue;
        }

        // read from client.
        if (true) {
            SrsCommonMessage* msg = NULL;
            ret = client->recv_message(&msg);
            
            srs_verbose("edge loop recv message. ret=%d", ret);
            if (ret != ERROR_SUCCESS && ret != ERROR_SOCKET_TIMEOUT) {
                srs_error("edge push get server control message failed. ret=%d", ret);
                send_error_code = ret;
                continue;
            }
            //为什么没见到msg的处理函数直接就释放了
           srs_freep(msg);
        }
        
        // forward all messages.
        // each msg in msgs.msgs must be free, for the SrsMessageArray never free them.
        int count = 0;
        if ((ret = queue->dump_packets(msgs.max, msgs.msgs, count)) != ERROR_SUCCESS) {
            srs_error("get message to push to origin failed. ret=%d", ret);
            return ret;
        }
        
        pprint->elapse();
        
        // pithy print
        if (pprint->can_print()) {
            kbps->sample();
            srs_trace("-> "SRS_CONSTS_LOG_EDGE_PUBLISH
                " time=%"PRId64", msgs=%d, okbps=%d,%d,%d, ikbps=%d,%d,%d", 
                pprint->age(), count,
                kbps->get_send_kbps(), kbps->get_send_kbps_30s(), kbps->get_send_kbps_5m(),
                kbps->get_recv_kbps(), kbps->get_recv_kbps_30s(), kbps->get_recv_kbps_5m());
        }
        // count 是 queue中消息的个数,也就是encoder发送到edge的rtmp msg得个数
// count<=0 没有包需要有 edge 转发到 origin
       // ignore when no messages.
        if (count <= 0) {
            srs_verbose("no packets to push.");
            continue;
        }
    
        // sendout messages, all messages are freed by send_and_free_messages().
        if ((ret = client->send_and_free_messages(msgs.msgs, count, stream_id)) != ERROR_SUCCESS) {
            srs_error("edge publish push message to server failed. ret=%d", ret);
            return ret;
        }
    }
    
    return ret;
}

SrsEdgeForwarder::cycle的主要功能

有 SrsRtmpClient类来完成

1. 调用SrsRtmpClient::recv_message从 origin接收消息

2. 

queue->dump_packets(msgs.max, msgs.msgs, count)将从encoder接收到的rtmp msg 保存在类型为

SrsMessageArray的变量msgs中,

client->send_and_free_messages(msgs.msgs, count, stream_id)将rtmp msg 转发到origin
client是 edge到 origin rtmp 连接,类型是SrsRtmpClient,
主要用于在encoder和origin转发 rtmp msg

 edge 是的推流rtmp msg就分析完了,没做过多处理转发到origin
接下来分析origin的rtmp msg处理

int SrsRtmpConn::acquire_publish(SrsSource* source, bool is_edge)
{
    int ret = ERROR_SUCCESS;

    if (!source->can_publish(is_edge)) {
        ret = ERROR_SYSTEM_STREAM_BUSY;
        srs_warn("stream %s is already publishing. ret=%d", 
            req->get_stream_url().c_str(), ret);
        return ret;
    }
    
    // when edge, ignore the publish event, directly proxy it.
    if (is_edge) {
//在这里启动一个SrsEdgeForwarder转发encoder的rtmp msg
      if ((ret = source->on_edge_start_publish()) != ERROR_SUCCESS) {
            srs_error("notice edge start publish stream failed. ret=%d", ret);
            return ret;
        }        
    } else {
// origin 会运行到此处,从SrsSource的on_publish开始分析
       if ((ret = source->on_publish()) != ERROR_SUCCESS) {
            srs_error("notify publish failed. ret=%d", ret);
            return ret;
        }
    }

    return ret;
}

int SrsSource::on_publish()
{
    int ret = ERROR_SUCCESS;
    
    // update the request object.
    srs_assert(_req);
    
    _can_publish = false;
    
    // whatever, the publish thread is the source or edge source,
    // save its id to srouce id.
// 更新_source_id,并通知所有的SrsConsumer(call SrsConsumer::update_source_id)

    on_source_id_changed(_srs_context->get_id());
    
    // reset the mix queue.
    mix_queue->clear();
    
    // detect the monotonically again.
    is_monotonically_increase = true;
    last_packet_time = 0;
    
    // create forwarders
// 在vhost 里配置 forward         127.0.0.1:1936 127.0.0.1:1937;
// 以后再具体分析
  if ((ret = create_forwarders()) != ERROR_SUCCESS) {
        srs_error("create forwarders failed. ret=%d", ret);
        return ret;
    }
    // 用 ffmpeg对流进行转码
// 配置 transcode --> engine --> output          rtmp://127.0.0.1:[port]/[app]?vhost=[vhost]/[stream]_[engine];
// 以后具体分析
   // TODO: FIXME: use initialize to set req.
#ifdef SRS_AUTO_TRANSCODE
    if ((ret = encoder->on_publish(_req)) != ERROR_SUCCESS) {
        srs_error("start encoder failed. ret=%d", ret);
        return ret;
    }
#endif
    
    // TODO: FIXME: use initialize to set req.
// hls相关,以后具体分析

#ifdef SRS_AUTO_HLS
    if ((ret = hls->on_publish(_req, false)) != ERROR_SUCCESS) {
        srs_error("start hls failed. ret=%d", ret);
        return ret;
    }
#endif
    //DVR 相关,以后具体分析
   // TODO: FIXME: use initialize to set req.
#ifdef SRS_AUTO_DVR
    if ((ret = dvr->on_publish(_req)) != ERROR_SUCCESS) {
        srs_error("start dvr failed. ret=%d", ret);
        return ret;
    }
#endif
//HDS相关,以后具体分析
ifdef SRS_AUTO_HDS
    if ((ret = hds->on_publish(_req)) != ERROR_SUCCESS) {
        srs_error("start hds failed. ret=%d", ret);
        return ret;
    }
#endif

    // notify the handler.
    srs_assert(handler);
    if ((ret = handler->on_publish(this, _req)) != ERROR_SUCCESS) {
        srs_error("handle on publish failed. ret=%d", ret);
        return ret;
    }
    SrsStatistic* stat = SrsStatistic::instance();
    stat->on_stream_publish(_req, _source_id);
    
    return ret;
}

主要分析

handler->on_publish(this, _req)

b srs_app_source.cpp:2203

推流后断下

bt command output above:

#0  SrsServer::on_publish (this=0x8d53e0, s=0x8fa0f0, r=0x8fcf00) at src/app/srs_app_server.cpp:1426
#1  0x000000000048e817 in SrsSource::on_publish (this=0x8fa0f0) at src/app/srs_app_source.cpp:2203
#2  0x0000000000481fb6 in SrsRtmpConn::acquire_publish (this=0x8f4ec0, source=0x8fa0f0, is_edge=false)
    at src/app/srs_app_rtmp_conn.cpp:980
#3  0x000000000048122e in SrsRtmpConn::publishing (this=0x8f4ec0, source=0x8fa0f0) at src/app/srs_app_rtmp_conn.cpp:847
#4  0x000000000047f759 in SrsRtmpConn::stream_service_cycle (this=0x8f4ec0) at src/app/srs_app_rtmp_conn.cpp:547
#5  0x000000000047e9d8 in SrsRtmpConn::service_cycle (this=0x8f4ec0) at src/app/srs_app_rtmp_conn.cpp:416
#6  0x000000000047d936 in SrsRtmpConn::do_cycle (this=0x8f4ec0) at src/app/srs_app_rtmp_conn.cpp:211
#7  0x000000000047bc6d in SrsConnection::cycle (this=0x8f4f48) at src/app/srs_app_conn.cpp:89
#8  0x00000000004ad6a3 in SrsOneCycleThread::cycle (this=0x8f4f90) at src/app/srs_app_thread.cpp:372
#9  0x00000000004ace3b in internal::SrsThread::thread_cycle (this=0x8f4fb0) at src/app/srs_app_thread.cpp:207
#10 0x00000000004ad049 in internal::SrsThread::thread_fun (arg=0x8f4fb0) at src/app/srs_app_thread.cpp:245
#11 0x0000000000535371 in _st_thread_main () at sched.c:327
#12 0x0000000000535ae1 in st_thread_create (start=0x7ffff7fdbc20, arg=0x1f7fdbb60, joinable=0, stk_size=5480568) at sched.c:591

SrsServer::on_publish代码如下

int SrsServer::on_publish(SrsSource* s, SrsRequest* r)
{
    int ret = ERROR_SUCCESS;
    
#ifdef SRS_AUTO_HTTP_SERVER
    if ((ret = http_server->http_mount(s, r)) != ERROR_SUCCESS) {
        return ret;
    }
#endif
    
    return ret;
}

SrsHttpServer::http_mount

参见http://www.cnblogs.com/yan-shi-yi/p/6837359.html