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 #ifndef MEDIA_BASE_DATA_BUFFER_H_
   6 #define MEDIA_BASE_DATA_BUFFER_H_
   7
   8 #include "base/logging.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/time/time.h"
  12 #include "media/base/media_export.h"
  13
  14 namespace media {
  15
  16 // A simple buffer that takes ownership of the given data pointer or allocates
  17 // as necessary.
  18 //
  19 // Unlike DecoderBuffer, allocations are assumed to be allocated with the
  20 // default memory allocator (i.e., new uint8[]).
  21 //
  22 // NOTE: It is illegal to call any method when end_of_stream() is true.
  23 class MEDIA_EXPORT DataBuffer : public base::RefCountedThreadSafe<DataBuffer> {
  24  public:
  25   // Allocates buffer of size |buffer_size| >= 0.
  26   explicit DataBuffer(int buffer_size);
  27
  28   // Assumes valid data of size |buffer_size|.
  29   DataBuffer(scoped_ptr<uint8[]> buffer, int buffer_size);
  30
  31   // Create a DataBuffer whose |data_| is copied from |data|.
  32   //
  33   // |data| must not be null and |size| must be >= 0.
  34   static scoped_refptr<DataBuffer> CopyFrom(const uint8* data, int size);
  35
  36   // Create a DataBuffer indicating we've reached end of stream.
  37   //
  38   // Calling any method other than end_of_stream() on the resulting buffer
  39   // is disallowed.
  40   static scoped_refptr<DataBuffer> CreateEOSBuffer();
  41
  42   base::TimeDelta timestamp() const {
  43     DCHECK(!end_of_stream());
  44     return timestamp_;
  45   }
  46
  47   void set_timestamp(const base::TimeDelta& timestamp) {
  48     DCHECK(!end_of_stream());
  49     timestamp_ = timestamp;
  50   }
  51
  52   base::TimeDelta duration() const {
  53     DCHECK(!end_of_stream());
  54     return duration_;
  55   }
  56
  57   void set_duration(const base::TimeDelta& duration) {
  58     DCHECK(!end_of_stream());
  59     duration_ = duration;
  60   }
  61
  62   const uint8* data() const {
  63     DCHECK(!end_of_stream());
  64     return data_.get();
  65   }
  66
  67   uint8* writable_data() {
  68     DCHECK(!end_of_stream());
  69     return data_.get();
  70   }
  71
  72   // The size of valid data in bytes.
  73   //
  74   // Setting this value beyond the buffer size is disallowed.
  75   int data_size() const {
  76     DCHECK(!end_of_stream());
  77     return data_size_;
  78   }
  79
  80   void set_data_size(int data_size) {
  81     DCHECK(!end_of_stream());
  82     CHECK_LE(data_size, buffer_size_);
  83     data_size_ = data_size;
  84   }
  85
  86   // If there's no data in this buffer, it represents end of stream.
  87   bool end_of_stream() const { return data_ == NULL; }
  88
  89  protected:
  90   friend class base::RefCountedThreadSafe<DataBuffer>;
  91
  92   // Allocates buffer of size |data_size|, copies [data,data+data_size) to
  93   // the allocated buffer and sets data size to |data_size|.
  94   //
  95   // If |data| is null an end of stream buffer is created.
  96   DataBuffer(const uint8* data, int data_size);
  97
  98   virtual ~DataBuffer();
  99
 100  private:
 101   base::TimeDelta timestamp_;
 102   base::TimeDelta duration_;
 103
 104   scoped_ptr<uint8[]> data_;
 105   int buffer_size_;
 106   int data_size_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(DataBuffer);
 109 };
 110
 111 }  // namespace media
 112
 113 #endif  // MEDIA_BASE_DATA_BUFFER_H_