buffer_reader.h

// Copyright 2014 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

#ifndef MEDIA_BASE_BUFFER_READER_H_
#define MEDIA_BASE_BUFFER_READER_H_

#include <stdint.h>

#include <string>
#include <vector>

#include "packager/base/compiler_specific.h"
#include "packager/base/macros.h"

namespace edash_packager {
namespace media {

class BufferReader {
 public:
  BufferReader(const uint8_t* buf, size_t size)
      : buf_(buf), size_(size), pos_(0) {}
  ~BufferReader() {}

  bool HasBytes(size_t count) { return pos() + count <= size(); }

  bool Read1(uint8_t* v) WARN_UNUSED_RESULT;
  bool Read2(uint16_t* v) WARN_UNUSED_RESULT;
  bool Read2s(int16_t* v) WARN_UNUSED_RESULT;
  bool Read4(uint32_t* v) WARN_UNUSED_RESULT;
  bool Read4s(int32_t* v) WARN_UNUSED_RESULT;
  bool Read8(uint64_t* v) WARN_UNUSED_RESULT;
  bool Read8s(int64_t* v) WARN_UNUSED_RESULT;

  bool ReadNBytesInto8(uint64_t* v, size_t num_bytes) WARN_UNUSED_RESULT;
  bool ReadNBytesInto8s(int64_t* v, size_t num_bytes) WARN_UNUSED_RESULT;

  bool ReadToVector(std::vector<uint8_t>* t, size_t count) WARN_UNUSED_RESULT;
  bool ReadToString(std::string* str, size_t size) WARN_UNUSED_RESULT;

  bool SkipBytes(size_t num_bytes) WARN_UNUSED_RESULT;

  const uint8_t* data() const { return buf_; }
  size_t size() const { return size_; }
  void set_size(size_t size) { size_ = size; }
  size_t pos() const { return pos_; }

 private:
  // Internal implementation of multi-byte reads.
  template <typename T>
  bool Read(T* t) WARN_UNUSED_RESULT;
  template <typename T>
  bool ReadNBytes(T* t, size_t num_bytes) WARN_UNUSED_RESULT;

  const uint8_t* buf_;
  size_t size_;
  size_t pos_;

  DISALLOW_COPY_AND_ASSIGN(BufferReader);
};

}  // namespace media
}  // namespace edash_packager

#endif  // MEDIA_BASE_BUFFER_READER_H_