修复addFFmpegSource添加的流事件拦截可能失效问题 (#2642 #2629)

此pr主要为了修复 #2629，通过新增getMuxer接口，
可以直接获取到所有协议共享的MultiMediaSourceMuxer对象，
在此对象完成事件拦截，防止某种协议事件丢失。
同时调整了下FFmpegSource.cpp代码格式。

src/Common/MediaSource.cpp

@@ -172,20 +172,8 @@ void MediaSource::setListener(const std::weak_ptr<MediaSourceEvent> &listener){
     _listener = listener;
 }
 
-std::weak_ptr<MediaSourceEvent> MediaSource::getListener(bool next) const{
-    if (!next) {
-        return _listener;
-    }
-
-    auto listener = dynamic_pointer_cast<MediaSourceEventInterceptor>(_listener.lock());
-    if (!listener) {
-        //不是MediaSourceEventInterceptor对象或者对象已经销毁
-        return _listener;
-    }
-    //获取被拦截的对象
-    auto next_obj = listener->getDelegate();
-    //有则返回之
-    return next_obj ? next_obj : _listener;
+std::weak_ptr<MediaSourceEvent> MediaSource::getListener() const {
+    return _listener;
 }
 
 int MediaSource::totalReaderCount(){
@@ -277,6 +265,11 @@ toolkit::EventPoller::Ptr MediaSource::getOwnerPoller() {
     throw std::runtime_error(toolkit::demangle(typeid(*this).name()) + "::getOwnerPoller failed: " + getUrl());
 }
 
+std::shared_ptr<MultiMediaSourceMuxer> MediaSource::getMuxer() {
+    auto listener = _listener.lock();
+    return listener ? listener->getMuxer(*this) : nullptr;
+}
+
 void MediaSource::onReaderChanged(int size) {
     try {
         weak_ptr<MediaSource> weak_self = shared_from_this();
@@ -780,6 +773,11 @@ toolkit::EventPoller::Ptr MediaSourceEventInterceptor::getOwnerPoller(MediaSourc
     throw std::runtime_error(toolkit::demangle(typeid(*this).name()) + "::getOwnerPoller failed");
 }
 
+std::shared_ptr<MultiMediaSourceMuxer> MediaSourceEventInterceptor::getMuxer(MediaSource &sender) {
+    auto listener = _listener.lock();
+    return listener ? listener->getMuxer(sender) : nullptr;
+}
+
 bool MediaSourceEventInterceptor::setupRecord(MediaSource &sender, Recorder::type type, bool start, const string &custom_path, size_t max_second) {
     auto listener = _listener.lock();
     if (!listener) {

src/Common/MediaSource.h

@@ -41,6 +41,7 @@ enum class MediaOriginType : uint8_t {
 std::string getOriginTypeString(MediaOriginType type);
 
 class MediaSource;
+class MultiMediaSourceMuxer;
 class MediaSourceEvent {
 public:
     friend class MediaSource;
@@ -88,6 +89,8 @@ public:
     virtual bool isRecording(MediaSource &sender, Recorder::type type) { return false; }
     // 获取所有track相关信息
     virtual std::vector<Track::Ptr> getMediaTracks(MediaSource &sender, bool trackReady = true) const { return std::vector<Track::Ptr>(); };
+    // 获取MultiMediaSourceMuxer对象
+    virtual std::shared_ptr<MultiMediaSourceMuxer> getMuxer(MediaSource &sender) { return nullptr; }
 
     class SendRtpArgs {
     public:
@@ -257,6 +260,7 @@ public:
     bool stopSendRtp(MediaSource &sender, const std::string &ssrc) override;
     float getLossRate(MediaSource &sender, TrackType type) override;
     toolkit::EventPoller::Ptr getOwnerPoller(MediaSource &sender) override;
+    std::shared_ptr<MultiMediaSourceMuxer> getMuxer(MediaSource &sender) override;
 
 private:
     std::weak_ptr<MediaSourceEvent> _listener;
@@ -330,7 +334,7 @@ public:
     // 设置监听者
     virtual void setListener(const std::weak_ptr<MediaSourceEvent> &listener);
     // 获取监听者
-    std::weak_ptr<MediaSourceEvent> getListener(bool next = false) const;
+    std::weak_ptr<MediaSourceEvent> getListener() const;
 
     // 本协议获取观看者个数，可能返回本协议的观看人数，也可能返回总人数
     virtual int readerCount() = 0;
@@ -372,6 +376,8 @@ public:
     float getLossRate(mediakit::TrackType type);
     // 获取所在线程
     toolkit::EventPoller::Ptr getOwnerPoller();
+    // 获取MultiMediaSourceMuxer对象
+    std::shared_ptr<MultiMediaSourceMuxer> getMuxer();
 
     ////////////////static方法，查找或生成MediaSource////////////////
 

src/Common/MultiMediaSourceMuxer.cpp

@@ -71,6 +71,14 @@ static string getTrackInfoStr(const TrackSource *track_src){
     return std::move(codec_info);
 }
 
+const ProtocolOption &MultiMediaSourceMuxer::getOption() const {
+    return _option;
+}
+
+const MediaTuple &MultiMediaSourceMuxer::getMediaTuple() const {
+    return _tuple;
+}
+
 std::string MultiMediaSourceMuxer::shortUrl() const {
     auto ret = getOriginUrl(MediaSource::NullMediaSource());
     if (!ret.empty()) {
@@ -361,6 +369,10 @@ EventPoller::Ptr MultiMediaSourceMuxer::getOwnerPoller(MediaSource &sender) {
     }
 }
 
+std::shared_ptr<MultiMediaSourceMuxer> MultiMediaSourceMuxer::getMuxer(MediaSource &sender) {
+    return shared_from_this();
+}
+
 bool MultiMediaSourceMuxer::onTrackReady(const Track::Ptr &track) {
     bool ret = false;
     if (_rtmp) {

src/Common/MultiMediaSourceMuxer.h

@@ -126,9 +126,13 @@ public:
      */
     toolkit::EventPoller::Ptr getOwnerPoller(MediaSource &sender) override;
 
-    const MediaTuple& getMediaTuple() const {
-        return _tuple;
-    }
+    /**
+     * 获取本对象
+     */
+    std::shared_ptr<MultiMediaSourceMuxer> getMuxer(MediaSource &sender) override;
+
+    const ProtocolOption &getOption() const;
+    const MediaTuple &getMediaTuple() const;
     std::string shortUrl() const;
 
 protected: