1 files changed, 197 insertions, 0 deletions
diff --git a/dom/media/webrtc/jsapi/RTCRtpScriptTransformer.h b/dom/media/webrtc/jsapi/RTCRtpScriptTransformer.h
new file mode 100644
index 0000000000..6d61ac3cd5
--- /dev/null
+++ b/dom/media/webrtc/jsapi/RTCRtpScriptTransformer.h
@@ -0,0 +1,197 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_DOM_MEDIA_WEBRTC_JSAPI_RTCRTPSCRIPTTRANSFORMER_H_
+#define MOZILLA_DOM_MEDIA_WEBRTC_JSAPI_RTCRTPSCRIPTTRANSFORMER_H_
+
+#include "nsISupports.h"
+#include "nsWrapperCache.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/dom/ReadableStream.h"
+#include "mozilla/dom/WritableStream.h"
+#include "mozilla/Maybe.h"
+#include "js/RootingAPI.h"
+#include "nsTArray.h"
+#include "nsCOMArray.h"
+#include <memory>
+#include "nsTHashSet.h"
+#include "nsCycleCollectionParticipant.h"
+
+class nsPIDOMWindowInner;
+
+namespace webrtc {
+class TransformableFrameInterface;
+}
+
+namespace mozilla {
+class FrameTransformerProxy;
+
+namespace dom {
+class Worker;
+class WorkerPrivate;
+
+// Dirt simple source for ReadableStream that accepts nsISupports
+// Might be suitable to move someplace else, with some polish.
+class nsISupportsStreamSource final : public UnderlyingSourceAlgorithmsWrapper {
+ public:
+  nsISupportsStreamSource();
+  nsISupportsStreamSource(const nsISupportsStreamSource&) = delete;
+  nsISupportsStreamSource(nsISupportsStreamSource&&) = delete;
+  nsISupportsStreamSource& operator=(const nsISupportsStreamSource&) = delete;
+  nsISupportsStreamSource& operator=(nsISupportsStreamSource&&) = delete;
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsISupportsStreamSource,
+                                           UnderlyingSourceAlgorithmsWrapper)
+
+  void Init(ReadableStream* aStream);
+
+  void Enqueue(nsISupports* aThing);
+
+  // From UnderlyingSourceAlgorithmsWrapper
+  already_AddRefed<Promise> PullCallbackImpl(
+      JSContext* aCx, ReadableStreamController& aController,
+      ErrorResult& aRv) override;
+
+  void EnqueueOneThingFromQueue(JSContext* aCx);
+
+ private:
+  virtual ~nsISupportsStreamSource();
+
+  // Calls ReadableStream::EnqueueNative, which is MOZ_CAN_RUN_SCRIPT.
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY void EnqueueToStream(JSContext* aCx,
+                                                   nsISupports* aThing);
+
+  RefPtr<ReadableStream> mStream;
+  RefPtr<Promise> mThingQueuedPromise;
+  // mozilla::Queue is not cycle-collector friendly :(
+  nsCOMArray<nsISupports> mQueue;
+};
+
+class RTCRtpScriptTransformer;
+
+class WritableStreamRTCFrameSink final
+    : public UnderlyingSinkAlgorithmsWrapper {
+ public:
+  explicit WritableStreamRTCFrameSink(RTCRtpScriptTransformer* aTransformer);
+  WritableStreamRTCFrameSink(const WritableStreamRTCFrameSink&) = delete;
+  WritableStreamRTCFrameSink(WritableStreamRTCFrameSink&&) = delete;
+  WritableStreamRTCFrameSink& operator=(const WritableStreamRTCFrameSink&) =
+      delete;
+  WritableStreamRTCFrameSink& operator=(WritableStreamRTCFrameSink&&) = delete;
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(WritableStreamRTCFrameSink,
+                                           UnderlyingSinkAlgorithmsWrapper)
+
+  already_AddRefed<Promise> WriteCallback(
+      JSContext* aCx, JS::Handle<JS::Value> aChunk,
+      WritableStreamDefaultController& aController,
+      ErrorResult& aError) override;
+
+ private:
+  virtual ~WritableStreamRTCFrameSink();
+  RefPtr<RTCRtpScriptTransformer> mTransformer;
+};
+
+class RTCEncodedFrameBase;
+
+// Here's the basic flow. All of this happens on the worker thread.
+// 0. We register with a FrameTransformerProxy.
+// 1. That FrameTransformerProxy dispatches webrtc::TransformableFrameInterface
+//    to us (from either the encoder/depacketizer thread), via our
+//    TransformFrame method.
+// 2. We wrap these frames in RTCEncodedAudio/VideoFrame, and feed them to
+//    mReadableSource, which queues them.
+// 3. mReadableSource.PullCallbackImpl consumes that queue, and feeds the
+//    frames to mReadable.
+// 4. JS worker code consumes from mReadable, does whatever transformation it
+//    wants, then writes the frames to mWritable.
+// 5. mWritableSink.WriteCallback passes those frames to us.
+// 6. We unwrap the webrtc::TransformableFrameInterface from these frames.
+// 7. We pass these unwrapped frames back to the FrameTransformerProxy.
+//    (FrameTransformerProxy handles any dispatching/synchronization necessary)
+// 8. Eventually, that FrameTransformerProxy calls NotifyReleased (possibly at
+//    our prompting).
+class RTCRtpScriptTransformer final : public nsISupports,
+                                      public nsWrapperCache {
+ public:
+  explicit RTCRtpScriptTransformer(nsIGlobalObject* aGlobal);
+
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY nsresult Init(JSContext* aCx,
+                                            JS::Handle<JS::Value> aOptions,
+                                            WorkerPrivate* aWorkerPrivate,
+                                            FrameTransformerProxy* aProxy);
+
+  void NotifyReleased();
+
+  void TransformFrame(
+      std::unique_ptr<webrtc::TransformableFrameInterface> aFrame);
+  already_AddRefed<Promise> OnTransformedFrame(RTCEncodedFrameBase* aFrame,
+                                               ErrorResult& aError);
+
+  // nsISupports
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(RTCRtpScriptTransformer)
+
+  JSObject* WrapObject(JSContext* aCx,
+                       JS::Handle<JSObject*> aGivenProto) override;
+
+  nsIGlobalObject* GetParentObject() const { return mGlobal; }
+
+  // WebIDL Interface
+  already_AddRefed<mozilla::dom::ReadableStream> Readable() const {
+    return do_AddRef(mReadable);
+  }
+  already_AddRefed<mozilla::dom::WritableStream> Writable() const {
+    return do_AddRef(mWritable);
+  }
+
+  void GetOptions(JSContext* aCx, JS::MutableHandle<JS::Value> aVal,
+                  ErrorResult& aError);
+
+  already_AddRefed<Promise> GenerateKeyFrame(const Optional<nsAString>& aRid);
+  void GenerateKeyFrameError(const Maybe<std::string>& aRid,
+                             const CopyableErrorResult& aResult);
+  already_AddRefed<Promise> SendKeyFrameRequest();
+  void KeyFrameRequestDone(bool aSuccess);
+
+  // Public to ease implementation of cycle collection functions
+  using GenerateKeyFramePromises =
+      nsTHashMap<nsCStringHashKey, nsTArray<RefPtr<Promise>>>;
+
+ private:
+  virtual ~RTCRtpScriptTransformer();
+  void RejectPendingPromises();
+  // empty string means no rid
+  void ResolveGenerateKeyFramePromises(const std::string& aRid,
+                                       uint64_t aTimestamp);
+
+  nsCOMPtr<nsIGlobalObject> mGlobal;
+
+  RefPtr<FrameTransformerProxy> mProxy;
+  RefPtr<nsISupportsStreamSource> mReadableSource;
+  RefPtr<ReadableStream> mReadable;
+  RefPtr<WritableStream> mWritable;
+  RefPtr<WritableStreamRTCFrameSink> mWritableSink;
+
+  JS::Heap<JS::Value> mOptions;
+  uint64_t mLastEnqueuedFrameCounter = 0;
+  uint64_t mLastReceivedFrameCounter = 0;
+  nsTArray<RefPtr<Promise>> mKeyFrameRequestPromises;
+  // Contains the promise returned for each call to GenerateKeyFrame(rid), in
+  // the order in which it was called, keyed by the rid (empty string if not
+  // passed). If there is already a promise in here for a given rid, we do not
+  // ask the FrameTransformerProxy again, and just bulk resolve/reject.
+  GenerateKeyFramePromises mGenerateKeyFramePromises;
+  Maybe<bool> mVideo;
+  RefPtr<StrongWorkerRef> mWorkerRef;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // MOZILLA_DOM_MEDIA_WEBRTC_JSAPI_RTCRTPSCRIPTTRANSFORMER_H_