Revert 70267 - Refactor PipelineImpl to use CompositeFilter to manage Filter ...

media/base/composite_filter.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef MEDIA_BASE_COMPOSITE_FILTER_H_
-#define MEDIA_BASE_COMPOSITE_FILTER_H_
-
-#include "base/thread.h"
-#include "media/base/filter_host.h"
-#include "media/base/filters.h"
-
-namespace media {
-
-class CompositeFilter : public Filter {
- public:
-  typedef base::Thread* (*ThreadFactoryFunction)(const char* thread_name);
-
-  CompositeFilter(MessageLoop* message_loop);
-
-  // Constructor that allows the default thread creation strategy to be
-  // overridden.
-  CompositeFilter(MessageLoop* message_loop,
-                  ThreadFactoryFunction thread_factory);
-
-  // Adds a filter to the composite. This is only allowed after set_host()
-  // is called and before the first state changing operation such as Play(),
-  // Flush(), Stop(), or Seek(). True is returned if the filter was successfully
-  // added to the composite. False is returned if the filter couldn't be added
-  // because the composite is in the wrong state or the filter needed a thread
-  // and the composite was unable to create one.
-  bool AddFilter(scoped_refptr<Filter> filter);
-
-  // media::Filter methods.
-  virtual const char* major_mime_type() const;
-  virtual void set_host(FilterHost* host);
-  virtual FilterHost* host();
-  virtual bool requires_message_loop() const;
-  virtual const char* message_loop_name() const;
-  virtual void set_message_loop(MessageLoop* message_loop);
-  virtual MessageLoop* message_loop();
-  virtual void Play(FilterCallback* play_callback);
-  virtual void Pause(FilterCallback* pause_callback);
-  virtual void Flush(FilterCallback* flush_callback);
-  virtual void Stop(FilterCallback* stop_callback);
-  virtual void SetPlaybackRate(float playback_rate);
-  virtual void Seek(base::TimeDelta time, FilterCallback* seek_callback);
-  virtual void OnAudioRendererDisabled();
-
- protected:
-  virtual ~CompositeFilter();
-
-  /// Default thread factory strategy.
-  static base::Thread* DefaultThreadFactory(const char* thread_name);
-
-  void SetError(PipelineError error);
-
- private:
-  class FilterHostImpl;
-
-  enum State {
-    kInvalid,
-    kCreated,
-    kPaused,
-    kPlayPending,
-    kStopWhilePlayPending,
-    kPlaying,
-    kPausePending,
-    kStopWhilePausePending,
-    kFlushPending,
-    kStopWhileFlushPending,
-    kSeekPending,
-    kStopWhileSeekPending,
-    kStopPending,
-    kStopped,
-    kError
-  };
-
-  // Initialization method called by constructors.
-  void Init(MessageLoop* message_loop, ThreadFactoryFunction thread_factory);
-
-  // Transition to a new state.
-  void ChangeState(State new_state);
-
-  // Start calling filters in a sequence.
-  void StartSerialCallSequence();
-
-  // Call filters in parallel.
-  void StartParallelCallSequence();
-
-  // Call the filter based on the current value of state_.
-  void CallFilter(scoped_refptr<Filter>& filter, FilterCallback* callback);
-
-  // Calls |callback_| and then clears the reference.
-  void DispatchPendingCallback();
-
-  // Gets the state to transition to given |state|.
-  State GetNextState(State state) const;
-
-  // Filter callback for a serial sequence.
-  void SerialCallback();
-
-  // Filter callback for a parallel sequence.
-  void ParallelCallback();
-
-  // Called when a parallel or serial call sequence completes.
-  void OnCallSequenceDone();
-
-  // Helper function for sending an error to the FilterHost.
-  void SendErrorToHost(PipelineError error);
-
-  // Helper function for handling errors during call sequences.
-  void HandleError(PipelineError error);
-
-  // Creates a callback that can be called from any thread, but is guaranteed
-  // to call the specified method on the thread associated with this filter.
-  FilterCallback* NewThreadSafeCallback(void (CompositeFilter::*method)());
-
-  // Helper function used by NewThreadSafeCallback() to make sure the
-  // method gets called on the right thread.
-  void OnCallback(MessageLoop* message_loop,
-                  void (CompositeFilter::*method)());
-
-  // Helper function that indicates whether SetError() calls can be forwarded
-  // to the host of this filter.
-  bool CanForwardError();
-
-  // Vector of threads owned by the composite and used by filters in |filters_|.
-  typedef std::vector<base::Thread*> FilterThreadVector;
-  FilterThreadVector filter_threads_;
-
-  // Vector of the filters added to the composite.
-  typedef std::vector<scoped_refptr<Filter> > FilterVector;
-  FilterVector filters_;
-
-  // Factory function used to create filter threads.
-  ThreadFactoryFunction thread_factory_;
-
-  // Callback for the pending request.
-  scoped_ptr<FilterCallback> callback_;
-
-  // Time parameter for the pending Seek() request.
-  base::TimeDelta pending_seek_time_;
-
-  // Current state of this filter.
-  State state_;
-
-  // The index of the filter currently processing a request.
-  unsigned int sequence_index_;
-
-  // Message loop passed into the constructor.
-  MessageLoop* message_loop_;
-
-  // FilterHost implementation passed to Filters owned by this
-  // object.
-  scoped_ptr<FilterHostImpl> host_impl_;
-
-  // Error passed in the last SetError() call.
-  PipelineError error_;
-
-  DISALLOW_COPY_AND_ASSIGN(CompositeFilter);
-};
-
-}  // namespace media
-
-#endif  // MEDIA_BASE_COMPOSITE_FILTER_H_