text: // 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 MEDIA_BASE_DATA_BUFFER_H_
  #define MEDIA_BASE_DATA_BUFFER_H_
  
  #include <stdint.h>
  
  #include <memory>
  
  #include "base/logging.h"
  #include "base/macros.h"
  #include "base/memory/ref_counted.h"
  #include "base/time/time.h"
  #include "media/base/media_export.h"
  
  namespace media {
  
  // A simple buffer that takes ownership of the given data pointer or allocates
  // as necessary.
  //
  // Unlike DecoderBuffer, allocations are assumed to be allocated with the
  // default memory allocator (i.e., new uint8_t[]).
  //
  // NOTE: It is illegal to call any method when end_of_stream() is true.
  class MEDIA_EXPORT DataBuffer : public base::RefCountedThreadSafe<DataBuffer> {
   public:
    // Allocates buffer of size |buffer_size| >= 0.
    explicit DataBuffer(int buffer_size);
  
    // Assumes valid data of size |buffer_size|.
    DataBuffer(std::unique_ptr<uint8_t[]> buffer, int buffer_size);
  
    // Create a DataBuffer whose |data_| is copied from |data|.
    //
    // |data| must not be null and |size| must be >= 0.
    static scoped_refptr<DataBuffer> CopyFrom(const uint8_t* data, int size);
  
    // Create a DataBuffer indicating we've reached end of stream.
    //
    // Calling any method other than end_of_stream() on the resulting buffer
    // is disallowed.
    static scoped_refptr<DataBuffer> CreateEOSBuffer();
  
    base::TimeDelta timestamp() const {
      DCHECK(!end_of_stream());
      return timestamp_;
    }
  
    void set_timestamp(const base::TimeDelta& timestamp) {
      DCHECK(!end_of_stream());
      timestamp_ = timestamp;
    }
  
    base::TimeDelta duration() const {
      DCHECK(!end_of_stream());
      return duration_;
    }
  
    void set_duration(const base::TimeDelta& duration) {
      DCHECK(!end_of_stream());
      duration_ = duration;
    }
  
    const uint8_t* data() const {
      DCHECK(!end_of_stream());
      return data_.get();
    }
  
    uint8_t* writable_data() {
      DCHECK(!end_of_stream());
      return data_.get();
    }
  
    // The size of valid data in bytes.
    //
    // Setting this value beyond the buffer size is disallowed.
    int data_size() const {
      DCHECK(!end_of_stream());
      return data_size_;
    }
  
    void set_data_size(int data_size) {
      DCHECK(!end_of_stream());
      CHECK_LE(data_size, buffer_size_);
      data_size_ = data_size;
    }
  
    // If there's no data in this buffer, it represents end of stream.
    bool end_of_stream() const { return data_ == NULL; }
  
   protected:
    friend class base::RefCountedThreadSafe<DataBuffer>;
  
    // Allocates buffer of size |data_size|, copies [data,data+data_size) to
    // the allocated buffer and sets data size to |data_size|.
    //
    // If |data| is null an end of stream buffer is created.
    DataBuffer(const uint8_t* data, int data_size);
  
    virtual ~DataBuffer();
  
   private:
    base::TimeDelta timestamp_;
    base::TimeDelta duration_;
  
    std::unique_ptr<uint8_t[]> data_;
    int buffer_size_;
    int data_size_;
  
    DISALLOW_COPY_AND_ASSIGN(DataBuffer);
  };
  
  }  // namespace media
  
  #endif  // MEDIA_BASE_DATA_BUFFER_H_
  