run_length_encoder.h

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/*
Copyright (c) 2010 Peter "Corsix" Cawley
 
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
 
#ifndef CORSIX_TH_RLE_H_
#define CORSIX_TH_RLE_H_
#include "config.h"
 
#include <vector>
 
class lua_persist_reader;
class lua_persist_writer;
 
 
class integer_run_length_encoder {
 public:
 
  explicit integer_run_length_encoder(size_t iRecordSize);
 
  void write(uint32_t iValue);
 
 
  void finish();
 
  const uint32_t* get_output(size_t* pCount) const;
  void pump_output(lua_persist_writer* pWriter) const;
 
 private:
 
  void flush(bool bAll);
 
  bool are_ranges_equal(size_t iObjIdx1, size_t iObjIdx2, size_t iOffset,
                        size_t iObjSize) const;
  bool move_object_to_output(size_t iObjSize, size_t iObjCount);
 
  std::vector<uint32_t> buffer;
  std::vector<uint32_t> output;
  size_t record_size;
  size_t buffer_size{};
  size_t buffer_offset{};
  size_t output_size{};
  size_t object_size{};
  size_t object_copies{};
};
 
class integer_run_length_decoder {
 public:
  integer_run_length_decoder(size_t iRecordSize, lua_persist_reader* pReader);
 
  uint32_t read();
  bool is_finished() const;
 
 private:
  std::vector<uint32_t> buffer;
 
  // Not owned by the decoder, the reader to read from.
  lua_persist_reader* reader;
 
  size_t reads_remaining{};
  size_t record_size;
  size_t object_copies{};
  size_t object_index{};
  size_t object_size{};
};
 
#endif  // CORSIX_TH_RLE_H_