dict_buffer.h

/*
* Copyright (c) 2018, Conor McCarthy
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/

#include "fast-lzma2.h"
#include "mem.h"
#include "data_block.h"
#ifndef NO_XXHASH
#  include "xxhash.h"
#endif

#ifndef FL2_DICT_BUFFER_H_
#define FL2_DICT_BUFFER_H_

#if defined (__cplusplus)
extern "C" {
#endif

/* DICT_buffer structure.
 * Maintains one or two dictionary buffers. In a dual dict configuration (asyc==1), when the
 * current buffer is full, the overlap region will be copied to the other buffer and it
 * becomes the destination for input while the first is compressed. This is useful when I/O
 * is much slower than compression. */
typedef struct {
    BYTE* data[2];
    size_t index;
    size_t async;
    size_t overlap;
    size_t start;  /* start = 0 (first block) or overlap */
    size_t end;    /* never < overlap */
    size_t size;   /* allocation size */
    size_t total;  /* total size compressed after last dict reset */
    size_t reset_interval;
#ifndef NO_XXHASH
    XXH32_state_t *xxh;
#endif
} DICT_buffer;

int DICT_construct(DICT_buffer *const buf, int const async);

int DICT_init(DICT_buffer *const buf, size_t const dict_size, size_t const overlap, unsigned const reset_multiplier, int const do_hash);

void DICT_destruct(DICT_buffer *const buf);

size_t DICT_size(const DICT_buffer *const buf);

size_t DICT_get(DICT_buffer *const buf, void **const dict);

int DICT_update(DICT_buffer *const buf, size_t const added_size);

void DICT_put(DICT_buffer *const buf, FL2_inBuffer* const input);

size_t DICT_availSpace(const DICT_buffer *const buf);

int DICT_hasUnprocessed(const DICT_buffer *const buf);

void DICT_getBlock(DICT_buffer *const buf, FL2_dataBlock *const block);

int DICT_needShift(DICT_buffer *const buf);

int DICT_async(const DICT_buffer *const buf);

void DICT_shift(DICT_buffer *const buf);

#ifndef NO_XXHASH
XXH32_hash_t DICT_getDigest(const DICT_buffer *const buf);
#endif

size_t DICT_memUsage(const DICT_buffer *const buf);

#if defined (__cplusplus)
}
#endif

#endif /* FL2_DICT_BUFFER_H_ */