[pcsx_rearmed.git] / deps / libchdr / deps / zstd-1.5.5 / lib / compress / zstd_ldm.h

/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * 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.
 */

#ifndef ZSTD_LDM_H
#define ZSTD_LDM_H

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

#include "zstd_compress_internal.h"   /* ldmParams_t, U32 */
#include "../zstd.h"   /* ZSTD_CCtx, size_t */

/*-*************************************
*  Long distance matching
***************************************/

#define ZSTD_LDM_DEFAULT_WINDOW_LOG ZSTD_WINDOWLOG_LIMIT_DEFAULT

void ZSTD_ldm_fillHashTable(
            ldmState_t* state, const BYTE* ip,
            const BYTE* iend, ldmParams_t const* params);

/**
 * ZSTD_ldm_generateSequences():
 *
 * Generates the sequences using the long distance match finder.
 * Generates long range matching sequences in `sequences`, which parse a prefix
 * of the source. `sequences` must be large enough to store every sequence,
 * which can be checked with `ZSTD_ldm_getMaxNbSeq()`.
 * @returns 0 or an error code.
 *
 * NOTE: The user must have called ZSTD_window_update() for all of the input
 * they have, even if they pass it to ZSTD_ldm_generateSequences() in chunks.
 * NOTE: This function returns an error if it runs out of space to store
 *       sequences.
 */
size_t ZSTD_ldm_generateSequences(
            ldmState_t* ldms, rawSeqStore_t* sequences,
            ldmParams_t const* params, void const* src, size_t srcSize);

/**
 * ZSTD_ldm_blockCompress():
 *
 * Compresses a block using the predefined sequences, along with a secondary
 * block compressor. The literals section of every sequence is passed to the
 * secondary block compressor, and those sequences are interspersed with the
 * predefined sequences. Returns the length of the last literals.
 * Updates `rawSeqStore.pos` to indicate how many sequences have been consumed.
 * `rawSeqStore.seq` may also be updated to split the last sequence between two
 * blocks.
 * @return The length of the last literals.
 *
 * NOTE: The source must be at most the maximum block size, but the predefined
 * sequences can be any size, and may be longer than the block. In the case that
 * they are longer than the block, the last sequences may need to be split into
 * two. We handle that case correctly, and update `rawSeqStore` appropriately.
 * NOTE: This function does not return any errors.
 */
size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
            ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
            ZSTD_paramSwitch_e useRowMatchFinder,
            void const* src, size_t srcSize);

/**
 * ZSTD_ldm_skipSequences():
 *
 * Skip past `srcSize` bytes worth of sequences in `rawSeqStore`.
 * Avoids emitting matches less than `minMatch` bytes.
 * Must be called for data that is not passed to ZSTD_ldm_blockCompress().
 */
void ZSTD_ldm_skipSequences(rawSeqStore_t* rawSeqStore, size_t srcSize,
    U32 const minMatch);

/* ZSTD_ldm_skipRawSeqStoreBytes():
 * Moves forward in rawSeqStore by nbBytes, updating fields 'pos' and 'posInSequence'.
 * Not to be used in conjunction with ZSTD_ldm_skipSequences().
 * Must be called for data with is not passed to ZSTD_ldm_blockCompress().
 */
void ZSTD_ldm_skipRawSeqStoreBytes(rawSeqStore_t* rawSeqStore, size_t nbBytes);

/** ZSTD_ldm_getTableSize() :
 *  Estimate the space needed for long distance matching tables or 0 if LDM is
 *  disabled.
 */
size_t ZSTD_ldm_getTableSize(ldmParams_t params);

/** ZSTD_ldm_getSeqSpace() :
 *  Return an upper bound on the number of sequences that can be produced by
 *  the long distance matcher, or 0 if LDM is disabled.
 */
size_t ZSTD_ldm_getMaxNbSeq(ldmParams_t params, size_t maxChunkSize);

/** ZSTD_ldm_adjustParameters() :
 *  If the params->hashRateLog is not set, set it to its default value based on
 *  windowLog and params->hashLog.
 *
 *  Ensures that params->bucketSizeLog is <= params->hashLog (setting it to
 *  params->hashLog if it is not).
 *
 *  Ensures that the minMatchLength >= targetLength during optimal parsing.
 */
void ZSTD_ldm_adjustParameters(ldmParams_t* params,
                               ZSTD_compressionParameters const* cParams);

#if defined (__cplusplus)
}
#endif

#endif /* ZSTD_FAST_H */
Commit	Line	Data
648db22b	1	/*
	2	* Copyright (c) Meta Platforms, Inc. and affiliates.
	3	* All rights reserved.
	4	*
	5	* This source code is licensed under both the BSD-style license (found in the
	6	* LICENSE file in the root directory of this source tree) and the GPLv2 (found
	7	* in the COPYING file in the root directory of this source tree).
	8	* You may select, at your option, one of the above-listed licenses.
	9	*/
	10
	11	#ifndef ZSTD_LDM_H
	12	#define ZSTD_LDM_H
	13
	14	#if defined (__cplusplus)
	15	extern "C" {
	16	#endif
	17
	18	#include "zstd_compress_internal.h" /* ldmParams_t, U32 */
	19	#include "../zstd.h" /* ZSTD_CCtx, size_t */
	20
	21	/-************************************
	22	* Long distance matching
	23	***************************************/
	24
	25	#define ZSTD_LDM_DEFAULT_WINDOW_LOG ZSTD_WINDOWLOG_LIMIT_DEFAULT
	26
	27	void ZSTD_ldm_fillHashTable(
	28	ldmState_t* state, const BYTE* ip,
	29	const BYTE* iend, ldmParams_t const* params);
	30
	31	/**
	32	* ZSTD_ldm_generateSequences():
	33	*
	34	* Generates the sequences using the long distance match finder.
	35	* Generates long range matching sequences in `sequences`, which parse a prefix
	36	* of the source. `sequences` must be large enough to store every sequence,
	37	* which can be checked with `ZSTD_ldm_getMaxNbSeq()`.
	38	* @returns 0 or an error code.
	39	*
	40	* NOTE: The user must have called ZSTD_window_update() for all of the input
	41	* they have, even if they pass it to ZSTD_ldm_generateSequences() in chunks.
	42	* NOTE: This function returns an error if it runs out of space to store
	43	* sequences.
	44	*/
	45	size_t ZSTD_ldm_generateSequences(
	46	ldmState_t* ldms, rawSeqStore_t* sequences,
	47	ldmParams_t const* params, void const* src, size_t srcSize);
	48
	49	/**
	50	* ZSTD_ldm_blockCompress():
	51	*
	52	* Compresses a block using the predefined sequences, along with a secondary
	53	* block compressor. The literals section of every sequence is passed to the
	54	* secondary block compressor, and those sequences are interspersed with the
	55	* predefined sequences. Returns the length of the last literals.
	56	* Updates `rawSeqStore.pos` to indicate how many sequences have been consumed.
	57	* `rawSeqStore.seq` may also be updated to split the last sequence between two
	58	* blocks.
	59	* @return The length of the last literals.
	60	*
	61	* NOTE: The source must be at most the maximum block size, but the predefined
	62	* sequences can be any size, and may be longer than the block. In the case that
	63	* they are longer than the block, the last sequences may need to be split into
	64	* two. We handle that case correctly, and update `rawSeqStore` appropriately.
65	* NOTE: This function does not return any errors.
66	*/
67	size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
68	ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
69	ZSTD_paramSwitch_e useRowMatchFinder,
70	void const* src, size_t srcSize);
71
72	/**
73	* ZSTD_ldm_skipSequences():
74	*
75	* Skip past `srcSize` bytes worth of sequences in `rawSeqStore`.
76	* Avoids emitting matches less than `minMatch` bytes.
77	* Must be called for data that is not passed to ZSTD_ldm_blockCompress().
78	*/
79	void ZSTD_ldm_skipSequences(rawSeqStore_t* rawSeqStore, size_t srcSize,
80	U32 const minMatch);
81
82	/* ZSTD_ldm_skipRawSeqStoreBytes():
83	* Moves forward in rawSeqStore by nbBytes, updating fields 'pos' and 'posInSequence'.
84	* Not to be used in conjunction with ZSTD_ldm_skipSequences().
85	* Must be called for data with is not passed to ZSTD_ldm_blockCompress().
86	*/
87	void ZSTD_ldm_skipRawSeqStoreBytes(rawSeqStore_t* rawSeqStore, size_t nbBytes);
88
89	/** ZSTD_ldm_getTableSize() :
90	* Estimate the space needed for long distance matching tables or 0 if LDM is
91	* disabled.
92	*/
93	size_t ZSTD_ldm_getTableSize(ldmParams_t params);
94
95	/** ZSTD_ldm_getSeqSpace() :
96	* Return an upper bound on the number of sequences that can be produced by
97	* the long distance matcher, or 0 if LDM is disabled.
98	*/
99	size_t ZSTD_ldm_getMaxNbSeq(ldmParams_t params, size_t maxChunkSize);
100
101	/** ZSTD_ldm_adjustParameters() :
102	* If the params->hashRateLog is not set, set it to its default value based on
103	* windowLog and params->hashLog.
104	*
105	* Ensures that params->bucketSizeLog is <= params->hashLog (setting it to
106	* params->hashLog if it is not).
107	*
108	* Ensures that the minMatchLength >= targetLength during optimal parsing.
109	*/
110	void ZSTD_ldm_adjustParameters(ldmParams_t* params,
111	ZSTD_compressionParameters const* cParams);
112
113	#if defined (__cplusplus)
114	}
115	#endif
116
117	#endif /* ZSTD_FAST_H */