cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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zstd_ldm.h (4305B)

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