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Diffstat (limited to 'src/liblzma/lz/lz_encoder.h')
| -rw-r--r-- | src/liblzma/lz/lz_encoder.h | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/liblzma/lz/lz_encoder.h b/src/liblzma/lz/lz_encoder.h new file mode 100644 index 00000000..b39c88e5 --- /dev/null +++ b/src/liblzma/lz/lz_encoder.h @@ -0,0 +1,161 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file lz_encoder.h +/// \brief LZ in window and match finder API +// +// Copyright (C) 1999-2006 Igor Pavlov +// Copyright (C) 2007 Lasse Collin +// +// This library is free software; you can redistribute it and/or +// modify it under the terms of the GNU Lesser General Public +// License as published by the Free Software Foundation; either +// version 2.1 of the License, or (at your option) any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// Lesser General Public License for more details. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef LZMA_LZ_ENCODER_H +#define LZMA_LZ_ENCODER_H + +#include "common.h" + + +typedef struct lzma_lz_encoder_s lzma_lz_encoder; +struct lzma_lz_encoder_s { + enum { + SEQ_INIT, + SEQ_RUN, + SEQ_FINISH, + SEQ_END + } sequence; + + bool (*process)(lzma_coder *coder, uint8_t *restrict out, + size_t *restrict out_pos, size_t out_size); + + lzma_vli uncompressed_size; + + /////////////// + // In Window // + /////////////// + + /// Pointer to buffer with data to be compressed + uint8_t *buffer; + + /// Total size of the allocated buffer (that is, including all + /// the extra space) + size_t size; + + /// Match finders store locations of matches using 32-bit integers. + /// To avoid adjusting several megabytes of integers every time the + /// input window is moved with move_window(), we only adjust the + /// offset of the buffer. Thus, buffer[match_finder_pos - offset] + /// is the byte pointed by match_finder_pos. + size_t offset; + + /// buffer[read_pos] is the current byte. + size_t read_pos; + + /// As long as read_pos is less than read_limit, there is enough + /// input available in buffer for at least one encoding loop. + /// + /// Because of the stateful API, read_limit may and will get greater + /// than read_pos quite often. This is taken into account when + /// calculating the value for keep_size_after. + size_t read_limit; + + /// buffer[write_pos] is the first byte that doesn't contain valid + /// uncompressed data; that is, the next input byte will be copied + /// to buffer[write_pos]. + size_t write_pos; + + /// When read_pos >= must_move_pos, move_window() must be called + /// to make more space for the input data. + size_t must_move_pos; + + /// Number of bytes that must be kept available in our input history. + /// That is, once keep_size_before bytes have been processed, + /// buffer[read_pos - keep_size_before] is the oldest byte that + /// must be available for reading. + size_t keep_size_before; + + /// Number of bytes that must be kept in buffer after read_pos. + /// That is, read_pos <= write_pos - keep_size_after as long as + /// stream_end_was_reached is false (once it is true, read_pos + /// is allowed to reach write_pos). + size_t keep_size_after; + + /// This is set to true once the last byte of the input data has + /// been copied to buffer. + bool stream_end_was_reached; + + ////////////////// + // Match Finder // + ////////////////// + + // Pointers to match finder functions + void (*get_matches)(lzma_lz_encoder *restrict lz, + uint32_t *restrict distances); + void (*skip)(lzma_lz_encoder *restrict lz, uint32_t num); + + // Match finder data + uint32_t *hash; // TODO: Check if hash aliases son + uint32_t *son; // and add 'restrict' if possible. + uint32_t cyclic_buffer_pos; + uint32_t cyclic_buffer_size; // Must be dictionary_size + 1. + uint32_t hash_mask; + uint32_t cut_value; + uint32_t hash_size_sum; + uint32_t num_items; + uint32_t match_max_len; +}; + + +#define LZMA_LZ_ENCODER_INIT \ + (lzma_lz_encoder){ \ + .buffer = NULL, \ + .size = 0, \ + .hash = NULL, \ + .num_items = 0, \ + } + + +/// Calculates +extern uint32_t lzma_lz_encoder_hash_properties(lzma_match_finder match_finder, + uint32_t history_size, uint32_t *restrict hash_mask, + uint32_t *restrict hash_size_sum, + uint32_t *restrict num_items); + +// NOTE: liblzma doesn't use callback API like LZMA SDK does. The caller +// must make sure that keep_size_after is big enough for single encoding pass +// i.e. keep_size_after >= maximum number of bytes possibly needed after +// the current position between calls to lzma_lz_read(). +extern lzma_ret lzma_lz_encoder_reset(lzma_lz_encoder *lz, + lzma_allocator *allocator, + bool (*process)(lzma_coder *coder, uint8_t *restrict out, + size_t *restrict out_pos, size_t out_size), + lzma_vli uncompressed_size, + size_t history_size, size_t additional_buffer_before, + size_t match_max_len, size_t additional_buffer_after, + lzma_match_finder match_finder, uint32_t match_finder_cycles, + const uint8_t *preset_dictionary, + size_t preset_dictionary_size); + +/// Frees memory allocated for in window and match finder buffers. +extern void lzma_lz_encoder_end( + lzma_lz_encoder *lz, lzma_allocator *allocator); + +extern lzma_ret lzma_lz_encode(lzma_coder *coder, + lzma_allocator *allocator lzma_attribute((unused)), + const uint8_t *restrict in, size_t *restrict in_pos, + size_t in_size, uint8_t *restrict out, + size_t *restrict out_pos, size_t out_size, + lzma_action action); + +/// This should not be called directly, but only via move_pos() macro. +extern void lzma_lz_encoder_normalize(lzma_lz_encoder *lz); + +#endif |