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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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