1 files changed, 184 insertions, 0 deletions
diff --git a/dom/media/MediaQueue.h b/dom/media/MediaQueue.h
new file mode 100644
index 000000000..ecbf1c7f5
--- /dev/null
+++ b/dom/media/MediaQueue.h
@@ -0,0 +1,184 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 http://mozilla.org/MPL/2.0/. */
+#if !defined(MediaQueue_h_)
+#define MediaQueue_h_
+
+#include "mozilla/ReentrantMonitor.h"
+#include "mozilla/TaskQueue.h"
+
+#include "nsDeque.h"
+#include "MediaEventSource.h"
+
+namespace mozilla {
+
+// Thread and type safe wrapper around nsDeque.
+template <class T>
+class MediaQueueDeallocator : public nsDequeFunctor {
+  virtual void* operator() (void* aObject) {
+    RefPtr<T> releaseMe = dont_AddRef(static_cast<T*>(aObject));
+    return nullptr;
+  }
+};
+
+template <class T>
+class MediaQueue : private nsDeque {
+public:
+  MediaQueue()
+    : nsDeque(new MediaQueueDeallocator<T>()),
+      mReentrantMonitor("mediaqueue"),
+      mEndOfStream(false)
+  {}
+
+  ~MediaQueue() {
+    Reset();
+  }
+
+  inline size_t GetSize() const {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    return nsDeque::GetSize();
+  }
+
+  inline void Push(T* aItem) {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    MOZ_ASSERT(aItem);
+    NS_ADDREF(aItem);
+    MOZ_ASSERT(aItem->GetEndTime() >= aItem->mTime);
+    nsDeque::Push(aItem);
+    mPushEvent.Notify(RefPtr<T>(aItem));
+  }
+
+  inline void PushFront(T* aItem) {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    MOZ_ASSERT(aItem);
+    NS_ADDREF(aItem);
+    nsDeque::PushFront(aItem);
+  }
+
+  inline already_AddRefed<T> PopFront() {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    RefPtr<T> rv = dont_AddRef(static_cast<T*>(nsDeque::PopFront()));
+    if (rv) {
+      mPopEvent.Notify(rv);
+    }
+    return rv.forget();
+  }
+
+  inline RefPtr<T> Peek() const {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    return static_cast<T*>(nsDeque::Peek());
+  }
+
+  inline RefPtr<T> PeekFront() const {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    return static_cast<T*>(nsDeque::PeekFront());
+  }
+
+  void Reset() {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    while (GetSize() > 0) {
+      RefPtr<T> x = dont_AddRef(static_cast<T*>(nsDeque::PopFront()));
+    }
+    mEndOfStream = false;
+  }
+
+  bool AtEndOfStream() const {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    return GetSize() == 0 && mEndOfStream;
+  }
+
+  // Returns true if the media queue has had its last item added to it.
+  // This happens when the media stream has been completely decoded. Note this
+  // does not mean that the corresponding stream has finished playback.
+  bool IsFinished() const {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    return mEndOfStream;
+  }
+
+  // Informs the media queue that it won't be receiving any more items.
+  void Finish() {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    mEndOfStream = true;
+    mFinishEvent.Notify();
+  }
+
+  // Returns the approximate number of microseconds of items in the queue.
+  int64_t Duration() {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    if (GetSize() == 0) {
+      return 0;
+    }
+    T* last = static_cast<T*>(nsDeque::Peek());
+    T* first = static_cast<T*>(nsDeque::PeekFront());
+    return last->GetEndTime() - first->mTime;
+  }
+
+  void LockedForEach(nsDequeFunctor& aFunctor) const {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    ForEach(aFunctor);
+  }
+
+  // Extracts elements from the queue into aResult, in order.
+  // Elements whose start time is before aTime are ignored.
+  void GetElementsAfter(int64_t aTime, nsTArray<RefPtr<T>>* aResult) {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    if (GetSize() == 0)
+      return;
+    size_t i;
+    for (i = GetSize() - 1; i > 0; --i) {
+      T* v = static_cast<T*>(ObjectAt(i));
+      if (v->GetEndTime() < aTime)
+        break;
+    }
+    // Elements less than i have a end time before aTime. It's also possible
+    // that the element at i has a end time before aTime, but that's OK.
+    for (; i < GetSize(); ++i) {
+      RefPtr<T> elem = static_cast<T*>(ObjectAt(static_cast<size_t>(i)));
+      aResult->AppendElement(elem);
+    }
+  }
+
+  void GetFirstElements(uint32_t aMaxElements, nsTArray<RefPtr<T>>* aResult) {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    for (size_t i = 0; i < aMaxElements && i < GetSize(); ++i) {
+      *aResult->AppendElement() = static_cast<T*>(ObjectAt(i));
+    }
+  }
+
+  uint32_t FrameCount() {
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    uint32_t frames = 0;
+    for (size_t i = 0; i < GetSize(); ++i) {
+      T* v = static_cast<T*>(ObjectAt(i));
+      frames += v->mFrames;
+    }
+    return frames;
+  }
+
+  MediaEventSource<RefPtr<T>>& PopEvent() {
+    return mPopEvent;
+  }
+
+  MediaEventSource<RefPtr<T>>& PushEvent() {
+    return mPushEvent;
+  }
+
+  MediaEventSource<void>& FinishEvent() {
+    return mFinishEvent;
+  }
+
+private:
+  mutable ReentrantMonitor mReentrantMonitor;
+  MediaEventProducer<RefPtr<T>> mPopEvent;
+  MediaEventProducer<RefPtr<T>> mPushEvent;
+  MediaEventProducer<void> mFinishEvent;
+  // True when we've decoded the last frame of data in the
+  // bitstream for which we're queueing frame data.
+  bool mEndOfStream;
+};
+
+} // namespace mozilla
+
+#endif