Checking in media::DataBuffer, a simple implementation of WritableBufferInterface.

media/base/buffers.h

 // Copyright (c) 2006-2008 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.
 
 // Defines various types of timestamped media buffers used for transporting
 // data between filters.  Every buffer contains a timestamp in microseconds
 // describing the relative position of the buffer within the media stream, and
 // the duration in microseconds for the length of time the buffer will be
 // rendered.
 //
@@ skipping 17 matching lines @@
 #define MEDIA_BASE_BUFFERS_H_
 
 #include "base/ref_counted.h"
 
 namespace media {
 
 class StreamSampleInterface :
     public base::RefCountedThreadSafe<StreamSampleInterface> {
  public:
   // Returns the timestamp of this buffer in microseconds.
-  virtual int64 GetTimestamp() = 0;
+  virtual int64 GetTimestamp() const = 0;
 
   // Returns the duration of this buffer in microseconds.
-  virtual int64 GetDuration() = 0;
+  virtual int64 GetDuration() const = 0;
 
   // Sets the timestamp of this buffer in microseconds.
   virtual void SetTimestamp(int64 timestamp) = 0;
 
   // Sets the duration of this buffer in microseconds.
   virtual void SetDuration(int64 duration) = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<StreamSampleInterface>;
   virtual ~StreamSampleInterface() {}
 };
 
 
 class BufferInterface : public StreamSampleInterface {
  public:
   // Returns a read only pointer to the buffer data.
-  virtual const char* GetData() = 0;
+  virtual const char* GetData() const = 0;
 
   // Returns the size of valid data in bytes.
-  virtual size_t GetDataSize() = 0;
+  virtual size_t GetDataSize() const = 0;
 };
 
 
 class WritableBufferInterface : public BufferInterface  {
  public:
   // Returns a read-write pointer to the buffer data.
   virtual char* GetWritableData() = 0;
 
   // Updates the size of valid data in bytes, which must be less than or equal
   // to GetBufferSize.
   virtual void SetDataSize(size_t data_size) = 0;
 
   // Returns the maximum allocated size for this buffer.
-  virtual size_t GetBufferSize() = 0;
+  virtual size_t GetBufferSize() const = 0;
 };
 
 
 struct VideoSurface {
   static const size_t kMaxPlanes = 3;
 
   // Surface formats roughly based on FOURCC labels, see:
   // http://www.fourcc.org/rgb.php
   // http://www.fourcc.org/yuv.php
   enum Format {
@@ skipping 74 matching lines @@
  private:
   OwnerType* owner_;
   scoped_refptr<BufferType> buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(AssignableBuffer);
 };
 
 } // namespace media
 
 #endif // MEDIA_BASE_BUFFERS_H_