media/base/data_buffer.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // A simple implementation of Buffer that takes ownership of the given data
   6 // pointer.
   7 //
   8 // DataBuffer assumes that memory was allocated with new uint8[].
   9
  10 #ifndef MEDIA_BASE_DATA_BUFFER_H_
  11 #define MEDIA_BASE_DATA_BUFFER_H_
  12
  13 #include "base/memory/scoped_ptr.h"
  14 #include "media/base/buffers.h"
  15
  16 namespace media {
  17
  18 class MEDIA_EXPORT DataBuffer : public Buffer {
  19  public:
  20   // Assumes valid data of size |buffer_size|.
  21   DataBuffer(scoped_array<uint8> buffer, int buffer_size);
  22
  23   // Allocates buffer of size |buffer_size|. If |buffer_size| is 0, |data_| is
  24   // set to a NULL ptr.
  25   explicit DataBuffer(int buffer_size);
  26
  27   // Allocates buffer of size |data_size|, copies [data,data+data_size) to
  28   // the allocated buffer and sets data size to |data_size|.
  29   DataBuffer(const uint8* data, int data_size);
  30
  31   // Buffer implementation.
  32   virtual const uint8* GetData() const OVERRIDE;
  33   virtual int GetDataSize() const OVERRIDE;
  34
  35   // Returns a read-write pointer to the buffer data.
  36   virtual uint8* GetWritableData();
  37
  38   // Updates the size of valid data in bytes, which must be less than or equal
  39   // to GetBufferSize().
  40   virtual void SetDataSize(int data_size);
  41
  42   // Returns the size of the underlying buffer.
  43   virtual int GetBufferSize() const;
  44
  45  protected:
  46   virtual ~DataBuffer();
  47
  48  private:
  49   // Constructor helper method for memory allocations.
  50   void Initialize();
  51
  52   scoped_array<uint8> data_;
  53   int buffer_size_;
  54   int data_size_;
  55
  56   DISALLOW_COPY_AND_ASSIGN(DataBuffer);
  57 };
  58
  59 }  // namespace media
  60
  61 #endif  // MEDIA_BASE_DATA_BUFFER_H_