1// Copyright (c) 2010 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 PDF_CHUNK_STREAM_H_
6#define PDF_CHUNK_STREAM_H_
7
8#include <stddef.h>
9
10#include <map>
11#include <vector>
12
13namespace chrome_pdf {
14
15// This class collects a chunks of data into one data stream. Client can check
16// if data in certain range is available, and get missing chunks of data.
17class ChunkStream {
18 public:
19  ChunkStream();
20  ~ChunkStream();
21
22  void Clear();
23
24  void Preallocate(size_t stream_size);
25  size_t GetSize();
26
27  bool WriteData(size_t offset, void* buffer, size_t size);
28  bool ReadData(size_t offset, size_t size, void* buffer) const;
29
30  // Returns vector of pairs where first is an offset, second is a size.
31  bool GetMissedRanges(size_t offset, size_t size,
32      std::vector<std::pair<size_t, size_t> >* ranges) const;
33  bool IsRangeAvailable(size_t offset, size_t size) const;
34  size_t GetFirstMissingByte() const;
35
36  size_t GetLastByteBefore(size_t offset) const;
37  size_t GetFirstByteAfter(size_t offset) const;
38
39 private:
40  std::vector<unsigned char> data_;
41
42  // Pair, first - begining of the chunk, second - size of the chunk.
43  std::map<size_t, size_t> chunks_;
44};
45
46};  // namespace chrome_pdf
47
48#endif
49