Speech refactoring: Turned AudioChunk into a refcounted class (CL1.4)

content/browser/speech/audio_buffer.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_SPEECH_AUDIO_BUFFER_H_
 #define CONTENT_BROWSER_SPEECH_AUDIO_BUFFER_H_
 #pragma once
 
 #include <string>
+#include <deque>

[hans, 2012/03/27 15:56:31]

nit: header includes should be sorted alphabetically

[Primiano Tucci (use gerrit), 2012/03/27 16:51:24]

Oops.

 
 #include "base/basictypes.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/scoped_vector.h"
+#include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 
 namespace speech {
 
 // Models a chunk derived from an AudioBuffer.
-class CONTENT_EXPORT AudioChunk {
+class CONTENT_EXPORT AudioChunk :
+    public base::RefCountedThreadSafe<AudioChunk> {

[hans, 2012/03/27 15:56:31]

just to double check: it needs to be thread safe because we pass this between
the IO and Audio threads?

[Primiano Tucci (use gerrit), 2012/03/27 16:51:24]

Right, it might happen that it is released and acquired simultaneously by,
respectively, IO and Audio threads in speech_recognizer_impl.cc

  public:
   explicit AudioChunk(int bytes_per_sample);
   AudioChunk(const uint8* data, size_t length, int bytes_per_sample);
 
   bool IsEmpty() const;
   int bytes_per_sample() const { return bytes_per_sample_; }
   size_t NumSamples() const;
   const std::string& AsString() const;
   int16 GetSample16(size_t index) const;
   const int16* SamplesData16() const;
   friend class AudioBuffer;
 
  private:
+  ~AudioChunk() {}
+  friend class base::RefCountedThreadSafe<AudioChunk>;
+
   std::string data_string_;
   int bytes_per_sample_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioChunk);
 };
 
 // Models an audio buffer. The current implementation relies on on-demand
 // allocations of AudioChunk(s) (which uses a string as storage).
 class AudioBuffer {
  public:
   explicit AudioBuffer(int bytes_per_sample);
   ~AudioBuffer();
 
   // Enqueues a copy of |length| bytes of |data| buffer.
   void Enqueue(const uint8* data, size_t length);
 
   // Dequeues, in FIFO order, a single chunk respecting the length of the
   // corresponding Enqueue call (in a nutshell: multiple Enqueue calls followed
   // by Dequeue calls will return the individual chunks without merging them).
-  scoped_ptr<AudioChunk> DequeueSingleChunk();
+  scoped_refptr<AudioChunk> DequeueSingleChunk();
 
   // Dequeues all previously enqueued chunks, merging them in a single chunk.
-  scoped_ptr<AudioChunk> DequeueAll();
+  scoped_refptr<AudioChunk> DequeueAll();
 
   // Removes and frees all the enqueued chunks.
   void Clear();
 
   // Checks whether the buffer is empty.
   bool IsEmpty() const;
 
  private:
-  typedef ScopedVector<AudioChunk> ChunksContainer;
+  typedef std::deque<scoped_refptr<AudioChunk> > ChunksContainer;
   ChunksContainer chunks_;
   int bytes_per_sample_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioBuffer);
 };
 
 }  // namespace speech
 
 #endif  // CONTENT_BROWSER_SPEECH_AUDIO_BUFFER_H_