1 ///////////////////////////////////////////////////////////////////////////////
4 /// \brief LZ in window and match finder API
6 // Copyright (C) 1999-2006 Igor Pavlov
7 // Copyright (C) 2007 Lasse Collin
9 // This library is free software; you can redistribute it and/or
10 // modify it under the terms of the GNU Lesser General Public
11 // License as published by the Free Software Foundation; either
12 // version 2.1 of the License, or (at your option) any later version.
14 // This library is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 // Lesser General Public License for more details.
19 ///////////////////////////////////////////////////////////////////////////////
21 #ifndef LZMA_LZ_ENCODER_H
22 #define LZMA_LZ_ENCODER_H
27 typedef struct lzma_lz_encoder_s lzma_lz_encoder;
28 struct lzma_lz_encoder_s {
36 bool (*process)(lzma_coder *coder, uint8_t *restrict out,
37 size_t *restrict out_pos, size_t out_size);
39 lzma_vli uncompressed_size;
45 /// Pointer to buffer with data to be compressed
48 /// Total size of the allocated buffer (that is, including all
52 /// Match finders store locations of matches using 32-bit integers.
53 /// To avoid adjusting several megabytes of integers every time the
54 /// input window is moved with move_window(), we only adjust the
55 /// offset of the buffer. Thus, buffer[match_finder_pos - offset]
56 /// is the byte pointed by match_finder_pos.
59 /// buffer[read_pos] is the current byte.
62 /// As long as read_pos is less than read_limit, there is enough
63 /// input available in buffer for at least one encoding loop.
65 /// Because of the stateful API, read_limit may and will get greater
66 /// than read_pos quite often. This is taken into account when
67 /// calculating the value for keep_size_after.
70 /// buffer[write_pos] is the first byte that doesn't contain valid
71 /// uncompressed data; that is, the next input byte will be copied
72 /// to buffer[write_pos].
75 /// When read_pos >= must_move_pos, move_window() must be called
76 /// to make more space for the input data.
79 /// Number of bytes that must be kept available in our input history.
80 /// That is, once keep_size_before bytes have been processed,
81 /// buffer[read_pos - keep_size_before] is the oldest byte that
82 /// must be available for reading.
83 size_t keep_size_before;
85 /// Number of bytes that must be kept in buffer after read_pos.
86 /// That is, read_pos <= write_pos - keep_size_after as long as
87 /// stream_end_was_reached is false (once it is true, read_pos
88 /// is allowed to reach write_pos).
89 size_t keep_size_after;
91 /// This is set to true once the last byte of the input data has
92 /// been copied to buffer.
93 bool stream_end_was_reached;
99 // Pointers to match finder functions
100 void (*get_matches)(lzma_lz_encoder *restrict lz,
101 uint32_t *restrict distances);
102 void (*skip)(lzma_lz_encoder *restrict lz, uint32_t num);
105 uint32_t *hash; // TODO: Check if hash aliases son
106 uint32_t *son; // and add 'restrict' if possible.
107 uint32_t cyclic_buffer_pos;
108 uint32_t cyclic_buffer_size; // Must be dictionary_size + 1.
111 uint32_t hash_size_sum;
113 uint32_t match_max_len;
117 #define LZMA_LZ_ENCODER_INIT \
127 extern uint32_t lzma_lz_encoder_hash_properties(lzma_match_finder match_finder,
128 uint32_t history_size, uint32_t *restrict hash_mask,
129 uint32_t *restrict hash_size_sum,
130 uint32_t *restrict num_items);
132 // NOTE: liblzma doesn't use callback API like LZMA SDK does. The caller
133 // must make sure that keep_size_after is big enough for single encoding pass
134 // i.e. keep_size_after >= maximum number of bytes possibly needed after
135 // the current position between calls to lzma_lz_read().
136 extern lzma_ret lzma_lz_encoder_reset(lzma_lz_encoder *lz,
137 lzma_allocator *allocator,
138 bool (*process)(lzma_coder *coder, uint8_t *restrict out,
139 size_t *restrict out_pos, size_t out_size),
140 lzma_vli uncompressed_size,
141 size_t history_size, size_t additional_buffer_before,
142 size_t match_max_len, size_t additional_buffer_after,
143 lzma_match_finder match_finder, uint32_t match_finder_cycles,
144 const uint8_t *preset_dictionary,
145 size_t preset_dictionary_size);
147 /// Frees memory allocated for in window and match finder buffers.
148 extern void lzma_lz_encoder_end(
149 lzma_lz_encoder *lz, lzma_allocator *allocator);
151 extern lzma_ret lzma_lz_encode(lzma_coder *coder,
152 lzma_allocator *allocator lzma_attribute((unused)),
153 const uint8_t *restrict in, size_t *restrict in_pos,
154 size_t in_size, uint8_t *restrict out,
155 size_t *restrict out_pos, size_t out_size,
158 /// This should not be called directly, but only via move_pos() macro.
159 extern void lzma_lz_encoder_normalize(lzma_lz_encoder *lz);