| // Copyright (c) 2010 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 PDF_CHUNK_STREAM_H_ |
| #define PDF_CHUNK_STREAM_H_ |
| |
| #include <stddef.h> |
| |
| #include <map> |
| #include <utility> |
| #include <vector> |
| |
| namespace chrome_pdf { |
| |
| // This class collects a chunks of data into one data stream. Client can check |
| // if data in certain range is available, and get missing chunks of data. |
| class ChunkStream { |
| public: |
| ChunkStream(); |
| ~ChunkStream(); |
| |
| void Clear(); |
| |
| void Preallocate(size_t stream_size); |
| size_t GetSize(); |
| |
| bool WriteData(size_t offset, void* buffer, size_t size); |
| bool ReadData(size_t offset, size_t size, void* buffer) const; |
| |
| // Returns vector of pairs where first is an offset, second is a size. |
| bool GetMissedRanges(size_t offset, size_t size, |
| std::vector<std::pair<size_t, size_t> >* ranges) const; |
| bool IsRangeAvailable(size_t offset, size_t size) const; |
| size_t GetFirstMissingByte() const; |
| |
| // Finds the first byte of the missing byte interval that offset belongs to. |
| size_t GetFirstMissingByteInInterval(size_t offset) const; |
| // Returns the last byte of the missing byte interval that offset belongs to. |
| size_t GetLastMissingByteInInterval(size_t offset) const; |
| |
| private: |
| std::vector<unsigned char> data_; |
| |
| // Pair, first - begining of the chunk, second - size of the chunk. |
| std::map<size_t, size_t> chunks_; |
| |
| size_t stream_size_; |
| }; |
| |
| }; // namespace chrome_pdf |
| |
| #endif // PDF_CHUNK_STREAM_H_ |