mirror of
https://github.com/facebook/zstd.git
synced 2025-11-03 00:08:51 -05:00
743 lines
37 KiB
C
743 lines
37 KiB
C
/*
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* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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/*-*************************************
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* Dependencies
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***************************************/
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#include "hist.h" /* HIST_countFast_wksp */
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#include "zstd_compress_internal.h"
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#include "zstd_compress_sequences.h"
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#include "zstd_compress_literals.h"
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#include "zstd_compress_superblock.h"
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/*-*************************************
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* Superblock entropy buffer structs
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***************************************/
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/** ZSTD_hufCTablesMetadata_t :
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* Stores Literals Block Type for a super-block in hType, and
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* huffman tree description in hufDesBuffer.
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* hufDesSize refers to the size of huffman tree description in bytes.
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* This metadata is populated in ZSTD_buildSuperBlockEntropy_literal() */
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typedef struct {
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symbolEncodingType_e hType;
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BYTE hufDesBuffer[500]; // TODO give name to this value
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size_t hufDesSize;
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} ZSTD_hufCTablesMetadata_t;
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/** ZSTD_fseCTablesMetadata_t :
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* Stores symbol compression modes for a super-block in {ll, ol, ml}Type, and
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* fse tables in fseTablesBuffer.
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* fseTablesSize refers to the size of fse tables in bytes.
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* This metadata is populated in ZSTD_buildSuperBlockEntropy_sequences() */
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typedef struct {
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symbolEncodingType_e llType;
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symbolEncodingType_e ofType;
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symbolEncodingType_e mlType;
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BYTE fseTablesBuffer[500]; // TODO give name to this value
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size_t fseTablesSize;
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size_t lastCountSize; // This is to account for bug in 1.3.4. More detail in ZSTD_compressSubBlock_sequences()
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} ZSTD_fseCTablesMetadata_t;
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typedef struct {
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ZSTD_hufCTablesMetadata_t hufMetadata;
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ZSTD_fseCTablesMetadata_t fseMetadata;
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} ZSTD_entropyCTablesMetadata_t;
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/** ZSTD_buildSuperBlockEntropy_literal() :
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* Builds entropy for the super-block literals.
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* Stores literals block type (raw, rle, compressed) and
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* huffman description table to hufMetadata.
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* Currently, this does not consider the option of reusing huffman table from
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* previous super-block. I think it would be a good improvement to add that option.
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* @return : size of huffman description table or error code */
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static size_t ZSTD_buildSuperBlockEntropy_literal(void* const src, size_t srcSize,
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const ZSTD_hufCTables_t* prevHuf,
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ZSTD_hufCTables_t* nextHuf,
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ZSTD_hufCTablesMetadata_t* hufMetadata,
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void* workspace, size_t wkspSize)
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{
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BYTE* const wkspStart = (BYTE*)workspace;
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BYTE* const wkspEnd = wkspStart + wkspSize;
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BYTE* const countWkspStart = wkspStart;
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unsigned* const countWksp = (unsigned*)workspace;
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const size_t countWkspSize = (HUF_SYMBOLVALUE_MAX + 1) * sizeof(unsigned);
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BYTE* const nodeWksp = countWkspStart + countWkspSize;
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const size_t nodeWkspSize = wkspEnd-nodeWksp;
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unsigned maxSymbolValue = 255;
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unsigned huffLog = 11;
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DEBUGLOG(5, "ZSTD_buildSuperBlockEntropy_literal (srcSize=%zu)", srcSize);
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/* Prepare nextEntropy assuming reusing the existing table */
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memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
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/* small ? don't even attempt compression (speed opt) */
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# define COMPRESS_LITERALS_SIZE_MIN 63
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{ size_t const minLitSize = COMPRESS_LITERALS_SIZE_MIN;
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if (srcSize <= minLitSize) { hufMetadata->hType = set_basic; return 0; }
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}
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/* Scan input and build symbol stats */
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{ size_t const largest = HIST_count_wksp (countWksp, &maxSymbolValue, (const BYTE*)src, srcSize, workspace, wkspSize);
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FORWARD_IF_ERROR(largest);
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if (largest == srcSize) { hufMetadata->hType = set_rle; return 0; }
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if (largest <= (srcSize >> 7)+4) { hufMetadata->hType = set_basic; return 0; }
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}
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/* Build Huffman Tree */
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memset(nextHuf->CTable, 0, sizeof(nextHuf->CTable));
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huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue);
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{ size_t const maxBits = HUF_buildCTable_wksp((HUF_CElt*)nextHuf->CTable, countWksp,
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maxSymbolValue, huffLog,
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nodeWksp, nodeWkspSize);
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FORWARD_IF_ERROR(maxBits);
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huffLog = (U32)maxBits;
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{ size_t cSize = HUF_estimateCompressedSize(
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(HUF_CElt*)nextHuf->CTable, countWksp, maxSymbolValue);
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size_t hSize = HUF_writeCTable(
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hufMetadata->hufDesBuffer, sizeof(hufMetadata->hufDesBuffer),
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(HUF_CElt*)nextHuf->CTable, maxSymbolValue, huffLog);
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if (cSize + hSize >= srcSize) { hufMetadata->hType = set_basic; return 0; }
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hufMetadata->hType = set_compressed;
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return hSize;
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}
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}
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}
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/** ZSTD_buildSuperBlockEntropy_sequences() :
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* Builds entropy for the super-block sequences.
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* Stores symbol compression modes and fse table to fseMetadata.
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* @return : size of fse tables or error code */
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static size_t ZSTD_buildSuperBlockEntropy_sequences(seqStore_t* seqStorePtr,
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const ZSTD_fseCTables_t* prevEntropy,
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ZSTD_fseCTables_t* nextEntropy,
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const ZSTD_CCtx_params* cctxParams,
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ZSTD_fseCTablesMetadata_t* fseMetadata,
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void* workspace, size_t wkspSize)
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{
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BYTE* const wkspStart = (BYTE*)workspace;
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BYTE* const wkspEnd = wkspStart + wkspSize;
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BYTE* const countWkspStart = wkspStart;
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unsigned* const countWksp = (unsigned*)workspace;
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const size_t countWkspSize = (MaxSeq + 1) * sizeof(unsigned);
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BYTE* const cTableWksp = countWkspStart + countWkspSize;
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const size_t cTableWkspSize = wkspEnd-cTableWksp;
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ZSTD_strategy const strategy = cctxParams->cParams.strategy;
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FSE_CTable* CTable_LitLength = nextEntropy->litlengthCTable;
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FSE_CTable* CTable_OffsetBits = nextEntropy->offcodeCTable;
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FSE_CTable* CTable_MatchLength = nextEntropy->matchlengthCTable;
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const BYTE* const ofCodeTable = seqStorePtr->ofCode;
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const BYTE* const llCodeTable = seqStorePtr->llCode;
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const BYTE* const mlCodeTable = seqStorePtr->mlCode;
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size_t const nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
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BYTE* const ostart = fseMetadata->fseTablesBuffer;
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BYTE* const oend = ostart + sizeof(fseMetadata->fseTablesBuffer);
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BYTE* op = ostart;
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assert(cTableWkspSize >= (1 << MaxFSELog) * sizeof(FSE_FUNCTION_TYPE));
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DEBUGLOG(5, "ZSTD_buildSuperBlockEntropy_sequences (nbSeq=%zu)", nbSeq);
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memset(workspace, 0, wkspSize);
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fseMetadata->lastCountSize = 0;
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/* convert length/distances into codes */
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ZSTD_seqToCodes(seqStorePtr);
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/* build CTable for Literal Lengths */
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{ U32 LLtype;
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unsigned max = MaxLL;
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size_t const mostFrequent = HIST_countFast_wksp(countWksp, &max, llCodeTable, nbSeq, workspace, wkspSize); /* can't fail */
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DEBUGLOG(5, "Building LL table");
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nextEntropy->litlength_repeatMode = prevEntropy->litlength_repeatMode;
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LLtype = ZSTD_selectEncodingType(&nextEntropy->litlength_repeatMode,
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countWksp, max, mostFrequent, nbSeq,
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LLFSELog, prevEntropy->litlengthCTable,
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LL_defaultNorm, LL_defaultNormLog,
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ZSTD_defaultAllowed, strategy);
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assert(set_basic < set_compressed && set_rle < set_compressed);
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assert(!(LLtype < set_compressed && nextEntropy->litlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
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{ size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_LitLength, LLFSELog, (symbolEncodingType_e)LLtype,
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countWksp, max, llCodeTable, nbSeq, LL_defaultNorm, LL_defaultNormLog, MaxLL,
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prevEntropy->litlengthCTable, sizeof(prevEntropy->litlengthCTable),
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cTableWksp, cTableWkspSize);
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FORWARD_IF_ERROR(countSize);
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if (LLtype == set_compressed)
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fseMetadata->lastCountSize = countSize;
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op += countSize;
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fseMetadata->llType = (symbolEncodingType_e) LLtype;
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} }
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/* build CTable for Offsets */
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{ U32 Offtype;
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unsigned max = MaxOff;
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size_t const mostFrequent = HIST_countFast_wksp(countWksp, &max, ofCodeTable, nbSeq, workspace, wkspSize); /* can't fail */
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/* We can only use the basic table if max <= DefaultMaxOff, otherwise the offsets are too large */
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ZSTD_defaultPolicy_e const defaultPolicy = (max <= DefaultMaxOff) ? ZSTD_defaultAllowed : ZSTD_defaultDisallowed;
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DEBUGLOG(5, "Building OF table");
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nextEntropy->offcode_repeatMode = prevEntropy->offcode_repeatMode;
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Offtype = ZSTD_selectEncodingType(&nextEntropy->offcode_repeatMode,
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countWksp, max, mostFrequent, nbSeq,
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OffFSELog, prevEntropy->offcodeCTable,
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OF_defaultNorm, OF_defaultNormLog,
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defaultPolicy, strategy);
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assert(!(Offtype < set_compressed && nextEntropy->offcode_repeatMode != FSE_repeat_none)); /* We don't copy tables */
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{ size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_OffsetBits, OffFSELog, (symbolEncodingType_e)Offtype,
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countWksp, max, ofCodeTable, nbSeq, OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
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prevEntropy->offcodeCTable, sizeof(prevEntropy->offcodeCTable),
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cTableWksp, cTableWkspSize);
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FORWARD_IF_ERROR(countSize);
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if (Offtype == set_compressed)
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fseMetadata->lastCountSize = countSize;
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op += countSize;
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fseMetadata->ofType = (symbolEncodingType_e) Offtype;
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} }
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/* build CTable for MatchLengths */
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{ U32 MLtype;
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unsigned max = MaxML;
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size_t const mostFrequent = HIST_countFast_wksp(countWksp, &max, mlCodeTable, nbSeq, workspace, wkspSize); /* can't fail */
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DEBUGLOG(5, "Building ML table (remaining space : %i)", (int)(oend-op));
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nextEntropy->matchlength_repeatMode = prevEntropy->matchlength_repeatMode;
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MLtype = ZSTD_selectEncodingType(&nextEntropy->matchlength_repeatMode,
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countWksp, max, mostFrequent, nbSeq,
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MLFSELog, prevEntropy->matchlengthCTable,
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ML_defaultNorm, ML_defaultNormLog,
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ZSTD_defaultAllowed, strategy);
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assert(!(MLtype < set_compressed && nextEntropy->matchlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
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{ size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_MatchLength, MLFSELog, (symbolEncodingType_e)MLtype,
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countWksp, max, mlCodeTable, nbSeq, ML_defaultNorm, ML_defaultNormLog, MaxML,
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prevEntropy->matchlengthCTable, sizeof(prevEntropy->matchlengthCTable),
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cTableWksp, cTableWkspSize);
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FORWARD_IF_ERROR(countSize);
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if (MLtype == set_compressed)
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fseMetadata->lastCountSize = countSize;
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op += countSize;
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fseMetadata->mlType = (symbolEncodingType_e) MLtype;
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} }
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assert((size_t) (op-ostart) <= sizeof(fseMetadata->fseTablesBuffer));
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return op-ostart;
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}
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/** ZSTD_buildSuperBlockEntropy() :
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* Builds entropy for the super-block.
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* @return : 0 on success or error code */
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static size_t
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ZSTD_buildSuperBlockEntropy(seqStore_t* seqStorePtr,
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const ZSTD_entropyCTables_t* prevEntropy,
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ZSTD_entropyCTables_t* nextEntropy,
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const ZSTD_CCtx_params* cctxParams,
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ZSTD_entropyCTablesMetadata_t* entropyMetadata,
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void* workspace, size_t wkspSize)
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{
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size_t const litSize = seqStorePtr->lit - seqStorePtr->litStart;
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DEBUGLOG(5, "ZSTD_buildSuperBlockEntropy");
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entropyMetadata->hufMetadata.hufDesSize =
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ZSTD_buildSuperBlockEntropy_literal(seqStorePtr->litStart, litSize,
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&prevEntropy->huf, &nextEntropy->huf,
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&entropyMetadata->hufMetadata,
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workspace, wkspSize);
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FORWARD_IF_ERROR(entropyMetadata->hufMetadata.hufDesSize);
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entropyMetadata->fseMetadata.fseTablesSize =
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ZSTD_buildSuperBlockEntropy_sequences(seqStorePtr,
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&prevEntropy->fse, &nextEntropy->fse,
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cctxParams,
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&entropyMetadata->fseMetadata,
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workspace, wkspSize);
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FORWARD_IF_ERROR(entropyMetadata->fseMetadata.fseTablesSize);
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return 0;
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}
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/** ZSTD_compressSubBlock_literal() :
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* Compresses literals section for a sub-block.
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* Compressed literal size needs to be less than uncompressed literal size.
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* ZSTD spec doesn't have this constaint. I will explain why I have this constraint here.
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* Literals section header size ranges from 1 to 5 bytes,
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* which is dictated by regenerated size and compressed size.
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* In order to figure out the memory address to start writing compressed literal,
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* it is necessary to figure out the literals section header size.
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* The challenge is that compressed size is only known after compression.
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* This is a chicken and egg problem.
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* I am simplifying the problem by assuming that
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* compressed size will always be less than or equal to regenerated size,
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* and using regenerated size to calculate literals section header size.
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* hufMetadata->hType has literals block type info.
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* If it is set_basic, all sub-blocks literals section will be Raw_Literals_Block.
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* If it is set_rle, all sub-blocks literals section will be RLE_Literals_Block.
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* If it is set_compressed, first sub-block's literals section will be Compressed_Literals_Block
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* and the following sub-blocks' literals sections will be Treeless_Literals_Block.
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* @return : compressed size of literals section of a sub-block
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* Or 0 if it unable to compress.
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* Or error code */
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static size_t ZSTD_compressSubBlock_literal(const HUF_CElt* hufTable,
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const ZSTD_hufCTablesMetadata_t* hufMetadata,
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const BYTE* literals, size_t litSize,
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void* dst, size_t dstSize,
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const int bmi2, int writeEntropy)
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{
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size_t const lhSize = 3 + (litSize >= 1 KB) + (litSize >= 16 KB);
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BYTE* const ostart = (BYTE*)dst;
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BYTE* const oend = ostart + dstSize;
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BYTE* op = ostart + lhSize;
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U32 singleStream = litSize < 256;
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symbolEncodingType_e hType = writeEntropy ? set_compressed : set_repeat;
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size_t cLitSize = 0;
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(void)bmi2; // TODO bmi2...
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DEBUGLOG(5, "ZSTD_compressSubBlock_literal (litSize=%zu, lhSize=%zu, writeEntropy=%d)", litSize, lhSize, writeEntropy);
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if (writeEntropy && litSize == 0) {
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/* Literals section cannot be compressed mode when litSize == 0.
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* (This seems to be decoder constraint.)
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* Entropy cannot be written if literals section is not compressed mode.
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*/
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return 0;
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}
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if (litSize == 0 || hufMetadata->hType == set_basic) {
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DEBUGLOG(5, "ZSTD_compressSubBlock_literal using raw literal");
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return ZSTD_noCompressLiterals(dst, dstSize, literals, litSize);
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} else if (hufMetadata->hType == set_rle) {
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DEBUGLOG(5, "ZSTD_compressSubBlock_literal using rle literal");
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return ZSTD_compressRleLiteralsBlock(dst, dstSize, literals, litSize);
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}
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if (lhSize == 3) singleStream = 1;
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if (writeEntropy) {
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memcpy(op, hufMetadata->hufDesBuffer, hufMetadata->hufDesSize);
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op += hufMetadata->hufDesSize;
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cLitSize += hufMetadata->hufDesSize;
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DEBUGLOG(5, "ZSTD_compressSubBlock_literal (hSize=%zu)", hufMetadata->hufDesSize);
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}
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// TODO bmi2
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{ const size_t cSize = singleStream ? HUF_compress1X_usingCTable(op, oend-op, literals, litSize, hufTable)
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: HUF_compress4X_usingCTable(op, oend-op, literals, litSize, hufTable);
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op += cSize;
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cLitSize += cSize;
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if (cSize == 0 || ERR_isError(cSize)) {
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return 0;
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}
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if (cLitSize > litSize) {
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if (writeEntropy) return 0;
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else return ZSTD_noCompressLiterals(dst, dstSize, literals, litSize);
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}
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DEBUGLOG(5, "ZSTD_compressSubBlock_literal (cSize=%zu)", cSize);
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}
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/* Build header */
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switch(lhSize)
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{
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case 3: /* 2 - 2 - 10 - 10 */
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{ U32 const lhc = hType + ((!singleStream) << 2) + ((U32)litSize<<4) + ((U32)cLitSize<<14);
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MEM_writeLE24(ostart, lhc);
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break;
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}
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case 4: /* 2 - 2 - 14 - 14 */
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{ U32 const lhc = hType + (2 << 2) + ((U32)litSize<<4) + ((U32)cLitSize<<18);
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MEM_writeLE32(ostart, lhc);
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break;
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}
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case 5: /* 2 - 2 - 18 - 18 */
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{ U32 const lhc = hType + (3 << 2) + ((U32)litSize<<4) + ((U32)cLitSize<<22);
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MEM_writeLE32(ostart, lhc);
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ostart[4] = (BYTE)(cLitSize >> 10);
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break;
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}
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default: /* not possible : lhSize is {3,4,5} */
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assert(0);
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}
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return op-ostart;
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}
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static size_t ZSTD_seqDecompressedSize(const seqDef* sequences, size_t nbSeq, size_t litSize) {
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const seqDef* const sstart = sequences;
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const seqDef* const send = sequences + nbSeq;
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const seqDef* sp = sstart;
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size_t matchLengthSum = 0;
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while (send-sp > 0) {
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matchLengthSum += sp->matchLength + MINMATCH;
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sp++;
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}
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return matchLengthSum + litSize;
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}
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/** ZSTD_compressSubBlock_sequences() :
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* Compresses sequences section for a sub-block.
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* fseMetadata->llType, fseMetadata->ofType, and fseMetadata->mlType have
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* symbol compression modes for the super-block.
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* First sub-block will have these in its header. The following sub-blocks
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* will always have repeat mode.
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* @return : compressed size of sequences section of a sub-block
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* Or 0 if it is unable to compress
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* Or error code. */
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static size_t ZSTD_compressSubBlock_sequences(const ZSTD_fseCTables_t* fseTables,
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const ZSTD_fseCTablesMetadata_t* fseMetadata,
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const seqDef* sequences, size_t nbSeq,
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const BYTE* llCode, const BYTE* mlCode, const BYTE* ofCode,
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const ZSTD_CCtx_params* cctxParams,
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void* dst, size_t dstCapacity,
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const int bmi2, int writeEntropy)
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{
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const int longOffsets = cctxParams->cParams.windowLog > STREAM_ACCUMULATOR_MIN;
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BYTE* const ostart = (BYTE*)dst;
|
|
BYTE* const oend = ostart + dstCapacity;
|
|
BYTE* op = ostart;
|
|
BYTE* seqHead;
|
|
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock_sequences (nbSeq=%zu, writeEntropy=%d, longOffsets=%d)", nbSeq, writeEntropy, longOffsets);
|
|
|
|
/* Sequences Header */
|
|
RETURN_ERROR_IF((oend-op) < 3 /*max nbSeq Size*/ + 1 /*seqHead*/,
|
|
dstSize_tooSmall);
|
|
if (nbSeq < 0x7F)
|
|
*op++ = (BYTE)nbSeq;
|
|
else if (nbSeq < LONGNBSEQ)
|
|
op[0] = (BYTE)((nbSeq>>8) + 0x80), op[1] = (BYTE)nbSeq, op+=2;
|
|
else
|
|
op[0]=0xFF, MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ)), op+=3;
|
|
if (writeEntropy && nbSeq == 0) {
|
|
return 0;
|
|
}
|
|
if (nbSeq==0) {
|
|
return op - ostart;
|
|
}
|
|
|
|
/* seqHead : flags for FSE encoding type */
|
|
seqHead = op++;
|
|
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock_sequences (seqHeadSize=%u)", (unsigned)(op-ostart));
|
|
|
|
if (writeEntropy) {
|
|
const U32 LLtype = fseMetadata->llType;
|
|
const U32 Offtype = fseMetadata->ofType;
|
|
const U32 MLtype = fseMetadata->mlType;
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock_sequences (fseTablesSize=%zu)", fseMetadata->fseTablesSize);
|
|
*seqHead = (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
|
|
memcpy(op, fseMetadata->fseTablesBuffer, fseMetadata->fseTablesSize);
|
|
op += fseMetadata->fseTablesSize;
|
|
} else {
|
|
const U32 repeat = set_repeat;
|
|
*seqHead = (BYTE)((repeat<<6) + (repeat<<4) + (repeat<<2));
|
|
}
|
|
|
|
{ size_t const bitstreamSize = ZSTD_encodeSequences(
|
|
op, oend - op,
|
|
fseTables->matchlengthCTable, mlCode,
|
|
fseTables->offcodeCTable, ofCode,
|
|
fseTables->litlengthCTable, llCode,
|
|
sequences, nbSeq,
|
|
longOffsets, bmi2);
|
|
FORWARD_IF_ERROR(bitstreamSize);
|
|
op += bitstreamSize;
|
|
/* zstd versions <= 1.3.4 mistakenly report corruption when
|
|
* FSE_readNCount() receives a buffer < 4 bytes.
|
|
* Fixed by https://github.com/facebook/zstd/pull/1146.
|
|
* This can happen when the last set_compressed table present is 2
|
|
* bytes and the bitstream is only one byte.
|
|
* In this exceedingly rare case, we will simply emit an uncompressed
|
|
* block, since it isn't worth optimizing.
|
|
*/
|
|
if (writeEntropy && fseMetadata->lastCountSize && fseMetadata->lastCountSize + bitstreamSize < 4) {
|
|
/* NCountSize >= 2 && bitstreamSize > 0 ==> lastCountSize == 3 */
|
|
assert(fseMetadata->lastCountSize + bitstreamSize == 3);
|
|
DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.3.4 by "
|
|
"emitting an uncompressed block.");
|
|
return 0;
|
|
}
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock_sequences (bitstreamSize=%zu)", bitstreamSize);
|
|
}
|
|
|
|
/* zstd versions <= 1.4.0 mistakenly report error when
|
|
* sequences section body size is less than 3 bytes.
|
|
* Fixed by https://github.com/facebook/zstd/pull/1664.
|
|
* This can happen when the previous sequences section block is compressed
|
|
* with rle mode and the current block's sequences section is compressed
|
|
* with repeat mode where sequences section body size can be 1 byte.
|
|
*/
|
|
if (op-seqHead < 4) {
|
|
return 0;
|
|
}
|
|
|
|
return op - ostart;
|
|
}
|
|
|
|
/** ZSTD_compressSubBlock() :
|
|
* Compresses a single sub-block.
|
|
* @return : compressed size of the sub-block
|
|
* Or 0 if it failed to compress. */
|
|
static size_t ZSTD_compressSubBlock(const ZSTD_entropyCTables_t* entropy,
|
|
const ZSTD_entropyCTablesMetadata_t* entropyMetadata,
|
|
const seqDef* sequences, size_t nbSeq,
|
|
const BYTE* literals, size_t litSize,
|
|
const BYTE* llCode, const BYTE* mlCode, const BYTE* ofCode,
|
|
const ZSTD_CCtx_params* cctxParams,
|
|
void* dst, size_t dstCapacity,
|
|
const int bmi2, int writeEntropy, U32 lastBlock)
|
|
{
|
|
BYTE* const ostart = (BYTE*)dst;
|
|
BYTE* const oend = ostart + dstCapacity;
|
|
BYTE* op = ostart + ZSTD_blockHeaderSize;
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock (litSize=%zu, nbSeq=%zu, writeEntropy=%d, lastBlock=%d)",
|
|
litSize, nbSeq, writeEntropy, lastBlock);
|
|
{ size_t cLitSize = ZSTD_compressSubBlock_literal((const HUF_CElt*)entropy->huf.CTable,
|
|
&entropyMetadata->hufMetadata, literals, litSize,
|
|
op, oend-op, bmi2, writeEntropy);
|
|
FORWARD_IF_ERROR(cLitSize);
|
|
if (cLitSize == 0) return 0;
|
|
op += cLitSize;
|
|
}
|
|
{ size_t cSeqSize = ZSTD_compressSubBlock_sequences(&entropy->fse,
|
|
&entropyMetadata->fseMetadata,
|
|
sequences, nbSeq,
|
|
llCode, mlCode, ofCode,
|
|
cctxParams,
|
|
op, oend-op,
|
|
bmi2, writeEntropy);
|
|
FORWARD_IF_ERROR(cSeqSize);
|
|
if (cSeqSize == 0) return 0;
|
|
op += cSeqSize;
|
|
}
|
|
/* Write block header */
|
|
{ size_t cSize = (op-ostart)-ZSTD_blockHeaderSize;
|
|
U32 const cBlockHeader24 = lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
|
|
MEM_writeLE24(ostart, cBlockHeader24);
|
|
}
|
|
return op-ostart;
|
|
}
|
|
|
|
static size_t ZSTD_estimateSubBlockSize_literal(const BYTE* literals, size_t litSize,
|
|
const ZSTD_hufCTables_t* huf,
|
|
const ZSTD_hufCTablesMetadata_t* hufMetadata,
|
|
void* workspace, size_t wkspSize,
|
|
int writeEntropy)
|
|
{
|
|
unsigned* const countWksp = (unsigned*)workspace;
|
|
unsigned maxSymbolValue = 255;
|
|
size_t literalSectionHeaderSize = 3; /* Use hard coded size of 3 bytes */
|
|
|
|
if (hufMetadata->hType == set_basic) return litSize;
|
|
else if (hufMetadata->hType == set_rle) return 1;
|
|
else if (hufMetadata->hType == set_compressed) {
|
|
size_t const largest = HIST_count_wksp (countWksp, &maxSymbolValue, (const BYTE*)literals, litSize, workspace, wkspSize);
|
|
if (ZSTD_isError(largest)) return litSize;
|
|
{ size_t cLitSizeEstimate = HUF_estimateCompressedSize((const HUF_CElt*)huf->CTable, countWksp, maxSymbolValue);
|
|
if (writeEntropy) cLitSizeEstimate += hufMetadata->hufDesSize;
|
|
return cLitSizeEstimate + literalSectionHeaderSize;
|
|
} }
|
|
assert(0); /* impossible */
|
|
return 0;
|
|
}
|
|
|
|
static size_t ZSTD_estimateSubBlockSize_symbolType(symbolEncodingType_e type,
|
|
const BYTE* codeTable, unsigned maxCode,
|
|
size_t nbSeq, const FSE_CTable* fseCTable,
|
|
const U32* additionalBits,
|
|
short const* defaultNorm, U32 defaultNormLog,
|
|
void* workspace, size_t wkspSize)
|
|
{
|
|
unsigned* const countWksp = (unsigned*)workspace;
|
|
const BYTE* ctp = codeTable;
|
|
const BYTE* const ctStart = ctp;
|
|
const BYTE* const ctEnd = ctStart + nbSeq;
|
|
size_t cSymbolTypeSizeEstimateInBits = 0;
|
|
unsigned max = maxCode;
|
|
|
|
HIST_countFast_wksp(countWksp, &max, codeTable, nbSeq, workspace, wkspSize); /* can't fail */
|
|
if (type == set_basic) {
|
|
cSymbolTypeSizeEstimateInBits = ZSTD_crossEntropyCost(defaultNorm, defaultNormLog, countWksp, max);
|
|
} else if (type == set_rle) {
|
|
cSymbolTypeSizeEstimateInBits = 0;
|
|
} else if (type == set_compressed || type == set_repeat) {
|
|
cSymbolTypeSizeEstimateInBits = ZSTD_fseBitCost(fseCTable, countWksp, max);
|
|
}
|
|
if (ZSTD_isError(cSymbolTypeSizeEstimateInBits)) return nbSeq * 10;
|
|
while (ctp < ctEnd) {
|
|
if (additionalBits) cSymbolTypeSizeEstimateInBits += additionalBits[*ctp];
|
|
else cSymbolTypeSizeEstimateInBits += *ctp; /* for offset, offset code is also the number of additional bits */
|
|
ctp++;
|
|
}
|
|
return cSymbolTypeSizeEstimateInBits / 8;
|
|
}
|
|
|
|
static size_t ZSTD_estimateSubBlockSize_sequences(const BYTE* ofCodeTable,
|
|
const BYTE* llCodeTable,
|
|
const BYTE* mlCodeTable,
|
|
size_t nbSeq,
|
|
const ZSTD_fseCTables_t* fseTables,
|
|
const ZSTD_fseCTablesMetadata_t* fseMetadata,
|
|
void* workspace, size_t wkspSize,
|
|
int writeEntropy)
|
|
{
|
|
size_t sequencesSectionHeaderSize = 3; /* Use hard coded size of 3 bytes */
|
|
size_t cSeqSizeEstimate = 0;
|
|
cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->ofType, ofCodeTable, MaxOff,
|
|
nbSeq, fseTables->offcodeCTable, NULL,
|
|
OF_defaultNorm, OF_defaultNormLog,
|
|
workspace, wkspSize);
|
|
cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->llType, llCodeTable, MaxLL,
|
|
nbSeq, fseTables->litlengthCTable, LL_bits,
|
|
LL_defaultNorm, LL_defaultNormLog,
|
|
workspace, wkspSize);
|
|
cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->mlType, mlCodeTable, MaxML,
|
|
nbSeq, fseTables->matchlengthCTable, ML_bits,
|
|
ML_defaultNorm, ML_defaultNormLog,
|
|
workspace, wkspSize);
|
|
if (writeEntropy) cSeqSizeEstimate += fseMetadata->fseTablesSize;
|
|
return cSeqSizeEstimate + sequencesSectionHeaderSize;
|
|
}
|
|
|
|
static size_t ZSTD_estimateSubBlockSize(const BYTE* literals, size_t litSize,
|
|
const BYTE* ofCodeTable,
|
|
const BYTE* llCodeTable,
|
|
const BYTE* mlCodeTable,
|
|
size_t nbSeq,
|
|
const ZSTD_entropyCTables_t* entropy,
|
|
const ZSTD_entropyCTablesMetadata_t* entropyMetadata,
|
|
void* workspace, size_t wkspSize,
|
|
int writeEntropy) {
|
|
size_t cSizeEstimate = 0;
|
|
cSizeEstimate += ZSTD_estimateSubBlockSize_literal(literals, litSize,
|
|
&entropy->huf, &entropyMetadata->hufMetadata,
|
|
workspace, wkspSize, writeEntropy);
|
|
cSizeEstimate += ZSTD_estimateSubBlockSize_sequences(ofCodeTable, llCodeTable, mlCodeTable,
|
|
nbSeq, &entropy->fse, &entropyMetadata->fseMetadata,
|
|
workspace, wkspSize, writeEntropy);
|
|
return cSizeEstimate + ZSTD_blockHeaderSize;
|
|
}
|
|
|
|
/** ZSTD_compressSubBlock_multi() :
|
|
* Breaks super-block into multiple sub-blocks and compresses them.
|
|
* Entropy will be written to the first block.
|
|
* The following blocks will use repeat mode to compress.
|
|
* All sub-blocks are compressed blocks (no raw or rle blocks).
|
|
* @return : compressed size of the super block (which is multiple ZSTD blocks)
|
|
* Or 0 if it failed to compress. */
|
|
static size_t ZSTD_compressSubBlock_multi(const seqStore_t* seqStorePtr,
|
|
const ZSTD_entropyCTables_t* entropy,
|
|
const ZSTD_entropyCTablesMetadata_t* entropyMetadata,
|
|
const ZSTD_CCtx_params* cctxParams,
|
|
void* dst, size_t dstCapacity,
|
|
const int bmi2, U32 lastBlock,
|
|
void* workspace, size_t wkspSize)
|
|
{
|
|
const seqDef* const sstart = seqStorePtr->sequencesStart;
|
|
const seqDef* const send = seqStorePtr->sequences;
|
|
const seqDef* sp = sstart;
|
|
const BYTE* const lstart = seqStorePtr->litStart;
|
|
const BYTE* const lend = seqStorePtr->lit;
|
|
const BYTE* lp = lstart;
|
|
BYTE* const ostart = (BYTE*)dst;
|
|
BYTE* const oend = ostart + dstCapacity;
|
|
BYTE* op = ostart;
|
|
const BYTE* llCodePtr = seqStorePtr->llCode;
|
|
const BYTE* mlCodePtr = seqStorePtr->mlCode;
|
|
const BYTE* ofCodePtr = seqStorePtr->ofCode;
|
|
size_t targetCBlockSize = cctxParams->targetCBlockSize;
|
|
size_t litSize, seqCount;
|
|
int writeEntropy = 1;
|
|
size_t remaining = ZSTD_seqDecompressedSize(sstart, send-sstart, lend-lstart);
|
|
size_t cBlockSizeEstimate = 0;
|
|
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock_multi (litSize=%u, nbSeq=%u)",
|
|
(unsigned)(lend-lp), (unsigned)(send-sstart));
|
|
|
|
litSize = 0;
|
|
seqCount = 0;
|
|
while (sp + seqCount < send) {
|
|
const seqDef* const sequence = sp + seqCount;
|
|
const U32 lastSequence = sequence+1 == send;
|
|
litSize = (sequence == send) ? (size_t)(lend-lp) : litSize + sequence->litLength;
|
|
seqCount++;
|
|
/* I think there is an optimization opportunity here.
|
|
* Calling ZSTD_estimateSubBlockSize for every sequence can be wasteful
|
|
* since it recalculates estimate from scratch.
|
|
* For example, it would recount literal distribution and symbol codes everytime.
|
|
*/
|
|
cBlockSizeEstimate = ZSTD_estimateSubBlockSize(lp, litSize, ofCodePtr, llCodePtr, mlCodePtr, seqCount,
|
|
entropy, entropyMetadata,
|
|
workspace, wkspSize, writeEntropy);
|
|
if (cBlockSizeEstimate > targetCBlockSize || lastSequence) {
|
|
const size_t decompressedSize = ZSTD_seqDecompressedSize(sp, seqCount, litSize);
|
|
const size_t cSize = ZSTD_compressSubBlock(entropy, entropyMetadata,
|
|
sp, seqCount,
|
|
lp, litSize,
|
|
llCodePtr, mlCodePtr, ofCodePtr,
|
|
cctxParams,
|
|
op, oend-op,
|
|
bmi2, writeEntropy, lastBlock && lastSequence);
|
|
FORWARD_IF_ERROR(cSize);
|
|
if (cSize > 0 && cSize < decompressedSize) {
|
|
assert(remaining >= decompressedSize);
|
|
remaining -= decompressedSize;
|
|
sp += seqCount;
|
|
lp += litSize;
|
|
op += cSize;
|
|
llCodePtr += seqCount;
|
|
mlCodePtr += seqCount;
|
|
ofCodePtr += seqCount;
|
|
litSize = 0;
|
|
seqCount = 0;
|
|
writeEntropy = 0; // Entropy only needs to be written once
|
|
}
|
|
}
|
|
}
|
|
if (remaining) {
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock_multi failed to compress");
|
|
return 0;
|
|
}
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock_multi compressed");
|
|
return op-ostart;
|
|
}
|
|
|
|
size_t ZSTD_compressSuperBlock(ZSTD_CCtx* zc,
|
|
void* dst, size_t dstCapacity,
|
|
unsigned lastBlock) {
|
|
ZSTD_entropyCTablesMetadata_t entropyMetadata;
|
|
|
|
FORWARD_IF_ERROR(ZSTD_buildSuperBlockEntropy(&zc->seqStore,
|
|
&zc->blockState.prevCBlock->entropy,
|
|
&zc->blockState.nextCBlock->entropy,
|
|
&zc->appliedParams,
|
|
&entropyMetadata,
|
|
zc->entropyWorkspace, HUF_WORKSPACE_SIZE /* statically allocated in resetCCtx */));
|
|
|
|
return ZSTD_compressSubBlock_multi(&zc->seqStore,
|
|
&zc->blockState.nextCBlock->entropy,
|
|
&entropyMetadata,
|
|
&zc->appliedParams,
|
|
dst, dstCapacity,
|
|
zc->bmi2, lastBlock,
|
|
zc->entropyWorkspace, HUF_WORKSPACE_SIZE /* statically allocated in resetCCtx */);
|
|
}
|
|
|
|
size_t ZSTD_noCompressSuperBlock(void* dst, size_t dstCapacity,
|
|
const void* src, size_t srcSize,
|
|
size_t targetCBlockSize,
|
|
unsigned lastBlock) {
|
|
const BYTE* const istart = (const BYTE*)src;
|
|
const BYTE* const iend = istart + srcSize;
|
|
const BYTE* ip = istart;
|
|
BYTE* const ostart = (BYTE*)dst;
|
|
BYTE* const oend = ostart + dstCapacity;
|
|
BYTE* op = ostart;
|
|
DEBUGLOG(5, "ZSTD_noCompressSuperBlock (dstCapacity=%zu, srcSize=%zu, targetCBlockSize=%zu)",
|
|
dstCapacity, srcSize, targetCBlockSize);
|
|
while (ip < iend) {
|
|
size_t remaining = iend-ip;
|
|
unsigned lastSubBlock = remaining <= targetCBlockSize;
|
|
size_t blockSize = lastSubBlock ? remaining : targetCBlockSize;
|
|
size_t cSize = ZSTD_noCompressBlock(op, oend-op, ip, blockSize, lastSubBlock && lastBlock);
|
|
FORWARD_IF_ERROR(cSize);
|
|
ip += blockSize;
|
|
op += cSize;
|
|
}
|
|
return op-ostart;
|
|
}
|