gecko-dev/dom/media/mediasource/SourceBufferResource.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=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 http://mozilla.org/MPL/2.0/. */

#ifndef MOZILLA_SOURCEBUFFERRESOURCE_H_
#define MOZILLA_SOURCEBUFFERRESOURCE_H_

#include "MediaCache.h"
#include "MediaResource.h"
#include "ResourceQueue.h"
#include "mozilla/Attributes.h"
#include "mozilla/ReentrantMonitor.h"
#include "nsCOMPtr.h"
#include "nsError.h"
#include "nsIPrincipal.h"
#include "nsString.h"
#include "nsTArray.h"
#include "nscore.h"
#include "prlog.h"

#define UNIMPLEMENTED() { /* Logging this is too spammy to do by default */ }

class nsIStreamListener;

namespace mozilla {

class MediaDecoder;
class LargeDataBuffer;

namespace dom {

class SourceBuffer;

}  // namespace dom

class SourceBufferResource final : public MediaResource
{
public:
  explicit SourceBufferResource(const nsACString& aType);
  virtual nsresult Close() override;
  virtual void Suspend(bool aCloseImmediately) override { UNIMPLEMENTED(); }
  virtual void Resume() override { UNIMPLEMENTED(); }
  virtual already_AddRefed<nsIPrincipal> GetCurrentPrincipal() override { UNIMPLEMENTED(); return nullptr; }
  virtual already_AddRefed<MediaResource> CloneData(MediaDecoder* aDecoder) override { UNIMPLEMENTED(); return nullptr; }
  virtual void SetReadMode(MediaCacheStream::ReadMode aMode) override { UNIMPLEMENTED(); }
  virtual void SetPlaybackRate(uint32_t aBytesPerSecond) override { UNIMPLEMENTED(); }
  virtual nsresult Read(char* aBuffer, uint32_t aCount, uint32_t* aBytes) override;
  virtual nsresult ReadAt(int64_t aOffset, char* aBuffer, uint32_t aCount, uint32_t* aBytes) override;
  virtual nsresult Seek(int32_t aWhence, int64_t aOffset) override;
  virtual int64_t Tell() override { return mOffset; }
  virtual void Pin() override { UNIMPLEMENTED(); }
  virtual void Unpin() override { UNIMPLEMENTED(); }
  virtual double GetDownloadRate(bool* aIsReliable) override { UNIMPLEMENTED(); *aIsReliable = false; return 0; }
  virtual int64_t GetLength() override { return mInputBuffer.GetLength(); }
  virtual int64_t GetNextCachedData(int64_t aOffset) override {
    ReentrantMonitorAutoEnter mon(mMonitor);
    MOZ_ASSERT(aOffset >= 0);
    if (uint64_t(aOffset) < mInputBuffer.GetOffset()) {
      return mInputBuffer.GetOffset();
    } else if (aOffset == GetLength()) {
      return -1;
    }
    return aOffset;
  }
  virtual int64_t GetCachedDataEnd(int64_t aOffset) override { UNIMPLEMENTED(); return -1; }
  virtual bool IsDataCachedToEndOfResource(int64_t aOffset) override { return false; }
  virtual bool IsSuspendedByCache() override { UNIMPLEMENTED(); return false; }
  virtual bool IsSuspended() override { UNIMPLEMENTED(); return false; }
  virtual nsresult ReadFromCache(char* aBuffer, int64_t aOffset, uint32_t aCount) override;
  virtual bool IsTransportSeekable() override { UNIMPLEMENTED(); return true; }
  virtual nsresult Open(nsIStreamListener** aStreamListener) override { UNIMPLEMENTED(); return NS_ERROR_FAILURE; }

  virtual nsresult GetCachedRanges(nsTArray<MediaByteRange>& aRanges) override
  {
    ReentrantMonitorAutoEnter mon(mMonitor);
    if (mInputBuffer.GetLength()) {
      aRanges.AppendElement(MediaByteRange(mInputBuffer.GetOffset(),
                                           mInputBuffer.GetLength()));
    }
    return NS_OK;
  }

  virtual const nsCString& GetContentType() const override { return mType; }

  virtual size_t SizeOfExcludingThis(
                      MallocSizeOf aMallocSizeOf) const override
  {
    ReentrantMonitorAutoEnter mon(mMonitor);

    size_t size = MediaResource::SizeOfExcludingThis(aMallocSizeOf);
    size += mType.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
    size += mInputBuffer.SizeOfExcludingThis(aMallocSizeOf);

    return size;
  }

  virtual size_t SizeOfIncludingThis(
                      MallocSizeOf aMallocSizeOf) const override
  {
    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
  }

  // Used by SourceBuffer.
  void AppendData(LargeDataBuffer* aData);
  void Ended();
  bool IsEnded()
  {
    ReentrantMonitorAutoEnter mon(mMonitor);
    return mEnded;
  }
  // Remove data from resource if it holds more than the threshold
  // number of bytes. Returns amount evicted.
  uint32_t EvictData(uint64_t aPlaybackOffset, uint32_t aThreshold);

  // Remove data from resource before the given offset.
  void EvictBefore(uint64_t aOffset);

  // Remove all data from the resource
  uint32_t EvictAll();

  // Returns the amount of data currently retained by this resource.
  int64_t GetSize() {
    ReentrantMonitorAutoEnter mon(mMonitor);
    return mInputBuffer.GetLength() - mInputBuffer.GetOffset();
  }

#if defined(DEBUG)
  void Dump(const char* aPath) {
    mInputBuffer.Dump(aPath);
  }
#endif

private:
  ~SourceBufferResource();
  nsresult SeekInternal(int64_t aOffset);
  nsresult ReadInternal(char* aBuffer, uint32_t aCount, uint32_t* aBytes, bool aMayBlock);
  nsresult ReadAtInternal(int64_t aOffset, char* aBuffer, uint32_t aCount, uint32_t* aBytes, bool aMayBlock);

  const nsCString mType;

  // Provides synchronization between SourceBuffers and InputAdapters.
  // Protects all of the member variables below.  Read() will await a
  // Notify() (from Seek, AppendData, Ended, or Close) when insufficient
  // data is available in mData.
  mutable ReentrantMonitor mMonitor;

  // The buffer holding resource data.
  ResourceQueue mInputBuffer;

  uint64_t mOffset;
  bool mClosed;
  bool mEnded;
};

} // namespace mozilla

#undef UNIMPLEMENTED

#endif /* MOZILLA_SOURCEBUFFERRESOURCE_H_ */