Support building WebRTC without audio and video for Android

webrtc/sdk/android/src/jni/ownedfactoryandthreads.h

+/*
+ *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_SDK_ANDROID_SRC_JNI_OWNEDFACTORYANDTHREADS_H_
+#define WEBRTC_SDK_ANDROID_SRC_JNI_OWNEDFACTORYANDTHREADS_H_
+
+#include <jni.h>
+#include <memory>
+#include <utility>
+
+#include "webrtc/api/peerconnectioninterface.h"
+#include "webrtc/base/thread.h"
+
+using cricket::WebRtcVideoDecoderFactory;
+using cricket::WebRtcVideoEncoderFactory;
+using rtc::Thread;
+using webrtc::PeerConnectionFactoryInterface;
+
+namespace webrtc_jni {
+
+PeerConnectionFactoryInterface* factoryFromJava(jlong j_p);
+
+// Helper struct for working around the fact that CreatePeerConnectionFactory()
+// comes in two flavors: either entirely automagical (constructing its own
+// threads and deleting them on teardown, but no external codec factory support)
+// or entirely manual (requires caller to delete threads after factory
+// teardown).  This struct takes ownership of its ctor's arguments to present a
+// single thing for Java to hold and eventually free.
+class OwnedFactoryAndThreads {
+ public:
+  OwnedFactoryAndThreads(std::unique_ptr<Thread> network_thread,
+                         std::unique_ptr<Thread> worker_thread,
+                         std::unique_ptr<Thread> signaling_thread,
+                         WebRtcVideoEncoderFactory* encoder_factory,
+                         WebRtcVideoDecoderFactory* decoder_factory,
+                         rtc::NetworkMonitorFactory* network_monitor_factory,
+                         PeerConnectionFactoryInterface* factory)
+      : network_thread_(std::move(network_thread)),
+        worker_thread_(std::move(worker_thread)),
+        signaling_thread_(std::move(signaling_thread)),
+        encoder_factory_(encoder_factory),
+        decoder_factory_(decoder_factory),
+        network_monitor_factory_(network_monitor_factory),
+        factory_(factory) {}
+
+  ~OwnedFactoryAndThreads();
+
+  PeerConnectionFactoryInterface* factory() { return factory_; }
+  Thread* signaling_thread() { return signaling_thread_.get(); }
+  Thread* worker_thread() { return worker_thread_.get(); }
+  WebRtcVideoEncoderFactory* encoder_factory() { return encoder_factory_; }
+  WebRtcVideoDecoderFactory* decoder_factory() { return decoder_factory_; }
+  rtc::NetworkMonitorFactory* network_monitor_factory() {
+    return network_monitor_factory_;
+  }
+  void clear_network_monitor_factory() { network_monitor_factory_ = nullptr; }
+  void InvokeJavaCallbacksOnFactoryThreads();
+
+ private:
+  void JavaCallbackOnFactoryThreads();
+
+  const std::unique_ptr<Thread> network_thread_;
+  const std::unique_ptr<Thread> worker_thread_;
+  const std::unique_ptr<Thread> signaling_thread_;
+  WebRtcVideoEncoderFactory* encoder_factory_;
+  WebRtcVideoDecoderFactory* decoder_factory_;
+  rtc::NetworkMonitorFactory* network_monitor_factory_;
+  PeerConnectionFactoryInterface* factory_;  // Const after ctor except dtor.
+};
+
+}  // namespace webrtc_jni
+
+#endif  // WEBRTC_SDK_ANDROID_SRC_JNI_OWNEDFACTORYANDTHREADS_H_