BaseMediaResource.h

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/* 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/. */

#ifndef BaseMediaResource_h

#define BaseMediaResource_h

#include "MediaResource.h"

#include "MediaResourceCallback.h"

#include "MediaCache.h"

#include "nsIChannel.h"

#include "nsIURI.h"

#include "nsIStreamListener.h"

#include "mozilla/dom/MediaDebugInfoBinding.h"

class nsIPrincipal;

namespace mozilla {

DDLoggedTypeDeclNameAndBase(BaseMediaResource, MediaResource);

class BaseMediaResource : public MediaResource,

                          public DecoderDoctorLifeLogger<BaseMediaResource> {

 public:

/**

   * Create a resource, reading data from the channel. Call on main thread only.

   * The caller must follow up by calling resource->Open().

*/

  static already_AddRefed<BaseMediaResource> Create(

      MediaResourceCallback* aCallback, nsIChannel* aChannel,

      bool aIsPrivateBrowsing);

  // Pass true to limit the amount of readahead data (specified by

  // "media.cache_readahead_limit") or false to read as much as the

  // cache size allows.

  virtual void ThrottleReadahead(bool bThrottle) {}

  // This is the client's estimate of the playback rate assuming

  // the media plays continuously. The cache can't guess this itself

  // because it doesn't know when the decoder was paused, buffering, etc.

  virtual void SetPlaybackRate(uint32_t aBytesPerSecond) = 0;

  // Get the estimated download rate in bytes per second (assuming no

  // pausing of the channel is requested by Gecko).

  // *aIsReliable is set to true if we think the estimate is useful.

  virtual double GetDownloadRate(bool* aIsReliable) = 0;

  // Moves any existing channel loads into or out of background. Background

  // loads don't block the load event. This also determines whether or not any

  // new loads initiated (for example to seek) will be in the background.

  void SetLoadInBackground(bool aLoadInBackground);

  // Suspend any downloads that are in progress.

  // If aCloseImmediately is set, resources should be released immediately

  // since we don't expect to resume again any time soon. Otherwise we

  // may resume again soon so resources should be held for a little

  // while.

  virtual void Suspend(bool aCloseImmediately) = 0;

  // Resume any downloads that have been suspended.

  virtual void Resume() = 0;

  // The mode is initially MODE_METADATA.

  virtual void SetReadMode(MediaCacheStream::ReadMode aMode) = 0;

  // Returns true if the resource can be seeked to unbuffered ranges, i.e.

  // for an HTTP network stream this returns true if HTTP1.1 Byte Range

  // requests are supported by the connection/server.

  virtual bool IsTransportSeekable() = 0;

  // Get the current principal for the channel

  virtual already_AddRefed<nsIPrincipal> GetCurrentPrincipal() = 0;

  // Return true if the loading of this resource required cross-origin

  // redirects.

  virtual bool HadCrossOriginRedirects() = 0;

/**

   * Open the stream. This creates a stream listener and returns it in

   * aStreamListener; this listener needs to be notified of incoming data.

*/

  virtual nsresult Open(nsIStreamListener** aStreamListener) = 0;

  // If this returns false, then we shouldn't try to clone this MediaResource

  // because its underlying resources are not suitable for reuse (e.g.

  // because the underlying connection has been lost, or this resource

  // just can't be safely cloned). If this returns true, CloneData could

  // still fail. If this returns false, CloneData should not be called.

  virtual bool CanClone() { return false; }

  // Create a new stream of the same type that refers to the same URI

  // with a new channel. Any cached data associated with the original

  // stream should be accessible in the new stream too.

  virtual already_AddRefed<BaseMediaResource> CloneData(

      MediaResourceCallback* aCallback) {

    return nullptr;

  // Returns true if the resource is a live stream.

  virtual bool IsLiveStream() const { return false; }

  virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {

    // Might be useful to track in the future:

    // - mChannel

    // - mURI (possibly owned, looks like just a ref from mChannel)

    // Not owned:

    // - mCallback

    return 0;

  virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {

    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);

  virtual void GetDebugInfo(dom::MediaResourceDebugInfo& aInfo) {}

 protected:

  BaseMediaResource(MediaResourceCallback* aCallback, nsIChannel* aChannel,

                    nsIURI* aURI)

      : mCallback(aCallback),

        mChannel(aChannel),

        mURI(aURI),

        mLoadInBackground(false) {}

  virtual ~BaseMediaResource() = default;

  // Set the request's load flags to aFlags.  If the request is part of a

  // load group, the request is removed from the group, the flags are set, and

  // then the request is added back to the load group.

  nsresult ModifyLoadFlags(nsLoadFlags aFlags);

  RefPtr<MediaResourceCallback> mCallback;

  // Channel used to download the media data. Must be accessed

  // from the main thread only.

  nsCOMPtr<nsIChannel> mChannel;

  // URI in case the stream needs to be re-opened. Access from

  // main thread only.

  nsCOMPtr<nsIURI> mURI;

  // True if SetLoadInBackground() has been called with

  // aLoadInBackground = true, i.e. when the document load event is not

  // blocked by this resource, and all channel loads will be in the

  // background.

  bool mLoadInBackground;

};

}  // namespace mozilla

#endif  // BaseMediaResource_h