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852 lines
42 KiB
852 lines
42 KiB
/* |
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* Copyright (c) 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 "zstd_compress_superblock.h" |
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|
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#include "../common/zstd_internal.h" /* ZSTD_getSequenceLength */ |
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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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|
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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[ZSTD_MAX_HUF_HEADER_SIZE]; |
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size_t hufDesSize; |
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} ZSTD_hufCTablesMetadata_t; |
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|
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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[ZSTD_MAX_FSE_HEADERS_SIZE]; |
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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, repeat) and |
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* huffman description table to hufMetadata. |
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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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const int disableLiteralsCompression, |
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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 = HUF_TABLELOG_DEFAULT; |
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HUF_repeat repeat = prevHuf->repeatMode; |
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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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ZSTD_memcpy(nextHuf, prevHuf, sizeof(*prevHuf)); |
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if (disableLiteralsCompression) { |
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DEBUGLOG(5, "set_basic - disabled"); |
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hufMetadata->hType = set_basic; |
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return 0; |
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} |
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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 = (prevHuf->repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN; |
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if (srcSize <= minLitSize) { |
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DEBUGLOG(5, "set_basic - too small"); |
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hufMetadata->hType = set_basic; |
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return 0; |
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} |
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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, "HIST_count_wksp failed"); |
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if (largest == srcSize) { |
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DEBUGLOG(5, "set_rle"); |
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hufMetadata->hType = set_rle; |
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return 0; |
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} |
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if (largest <= (srcSize >> 7)+4) { |
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DEBUGLOG(5, "set_basic - no gain"); |
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hufMetadata->hType = set_basic; |
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return 0; |
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} |
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} |
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/* Validate the previous Huffman table */ |
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if (repeat == HUF_repeat_check && !HUF_validateCTable((HUF_CElt const*)prevHuf->CTable, countWksp, maxSymbolValue)) { |
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repeat = HUF_repeat_none; |
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} |
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/* Build Huffman Tree */ |
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ZSTD_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, "HUF_buildCTable_wksp"); |
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huffLog = (U32)maxBits; |
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{ /* Build and write the CTable */ |
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size_t const newCSize = HUF_estimateCompressedSize( |
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(HUF_CElt*)nextHuf->CTable, countWksp, maxSymbolValue); |
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size_t const hSize = HUF_writeCTable_wksp( |
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hufMetadata->hufDesBuffer, sizeof(hufMetadata->hufDesBuffer), |
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(HUF_CElt*)nextHuf->CTable, maxSymbolValue, huffLog, |
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nodeWksp, nodeWkspSize); |
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/* Check against repeating the previous CTable */ |
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if (repeat != HUF_repeat_none) { |
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size_t const oldCSize = HUF_estimateCompressedSize( |
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(HUF_CElt const*)prevHuf->CTable, countWksp, maxSymbolValue); |
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if (oldCSize < srcSize && (oldCSize <= hSize + newCSize || hSize + 12 >= srcSize)) { |
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DEBUGLOG(5, "set_repeat - smaller"); |
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ZSTD_memcpy(nextHuf, prevHuf, sizeof(*prevHuf)); |
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hufMetadata->hType = set_repeat; |
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return 0; |
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} |
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} |
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if (newCSize + hSize >= srcSize) { |
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DEBUGLOG(5, "set_basic - no gains"); |
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ZSTD_memcpy(nextHuf, prevHuf, sizeof(*prevHuf)); |
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hufMetadata->hType = set_basic; |
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return 0; |
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} |
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DEBUGLOG(5, "set_compressed (hSize=%u)", (U32)hSize); |
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hufMetadata->hType = set_compressed; |
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nextHuf->repeatMode = HUF_repeat_check; |
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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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ZSTD_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, "ZSTD_buildCTable for LitLens failed"); |
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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, "ZSTD_buildCTable for Offsets failed"); |
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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, "ZSTD_buildCTable for MatchLengths failed"); |
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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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ZSTD_disableLiteralsCompression(cctxParams), |
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workspace, wkspSize); |
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FORWARD_IF_ERROR(entropyMetadata->hufMetadata.hufDesSize, "ZSTD_buildSuperBlockEntropy_literal failed"); |
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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, "ZSTD_buildSuperBlockEntropy_sequences failed"); |
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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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* When we have to write the Huffman table we will sometimes choose a header |
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* size larger than necessary. This is because we have to pick the header size |
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* before we know the table size + compressed size, so we have a bound on the |
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* table size. If we guessed incorrectly, we fall back to uncompressed literals. |
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* |
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* We write the header when writeEntropy=1 and set entropyWritten=1 when we succeeded |
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* in writing the header, otherwise it is set to 0. |
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* |
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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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* If it is set_compressed, first sub-block's literals section will be Treeless_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, int* entropyWritten) |
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{ |
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size_t const header = writeEntropy ? 200 : 0; |
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size_t const lhSize = 3 + (litSize >= (1 KB - header)) + (litSize >= (16 KB - header)); |
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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 const singleStream = lhSize == 3; |
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symbolEncodingType_e hType = writeEntropy ? hufMetadata->hType : 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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*entropyWritten = 0; |
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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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assert(litSize > 0); |
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assert(hufMetadata->hType == set_compressed || hufMetadata->hType == set_repeat); |
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if (writeEntropy && hufMetadata->hType == set_compressed) { |
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ZSTD_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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DEBUGLOG(5, "Failed to write entropy tables %s", ZSTD_getErrorName(cSize)); |
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return 0; |
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} |
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/* If we expand and we aren't writing a header then emit uncompressed */ |
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if (!writeEntropy && cLitSize >= litSize) { |
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DEBUGLOG(5, "ZSTD_compressSubBlock_literal using raw literal because uncompressible"); |
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return ZSTD_noCompressLiterals(dst, dstSize, literals, litSize); |
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} |
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/* If we are writing headers then allow expansion that doesn't change our header size. */ |
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if (lhSize < (size_t)(3 + (cLitSize >= 1 KB) + (cLitSize >= 16 KB))) { |
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assert(cLitSize > litSize); |
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DEBUGLOG(5, "Literals expanded beyond allowed header size"); |
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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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|
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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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*entropyWritten = 1; |
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DEBUGLOG(5, "Compressed literals: %u -> %u", (U32)litSize, (U32)(op-ostart)); |
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return op-ostart; |
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} |
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static size_t ZSTD_seqDecompressedSize(seqStore_t const* seqStore, const seqDef* sequences, size_t nbSeq, size_t litSize, int lastSequence) { |
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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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size_t litLengthSum = 0; |
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/* Only used by assert(), suppress unused variable warnings in production. */ |
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(void)litLengthSum; |
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while (send-sp > 0) { |
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ZSTD_sequenceLength const seqLen = ZSTD_getSequenceLength(seqStore, sp); |
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litLengthSum += seqLen.litLength; |
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matchLengthSum += seqLen.matchLength; |
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sp++; |
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} |
|
assert(litLengthSum <= litSize); |
|
if (!lastSequence) { |
|
assert(litLengthSum == litSize); |
|
} |
|
return matchLengthSum + litSize; |
|
} |
|
|
|
/* ZSTD_compressSubBlock_sequences() : |
|
* Compresses sequences section for a sub-block. |
|
* fseMetadata->llType, fseMetadata->ofType, and fseMetadata->mlType have |
|
* symbol compression modes for the super-block. |
|
* The first successfully compressed block will have these in its header. |
|
* We set entropyWritten=1 when we succeed in compressing the sequences. |
|
* The following sub-blocks will always have repeat mode. |
|
* @return : compressed size of sequences section of a sub-block |
|
* Or 0 if it is unable to compress |
|
* Or error code. */ |
|
static size_t ZSTD_compressSubBlock_sequences(const ZSTD_fseCTables_t* fseTables, |
|
const ZSTD_fseCTablesMetadata_t* fseMetadata, |
|
const seqDef* sequences, size_t nbSeq, |
|
const BYTE* llCode, const BYTE* mlCode, const BYTE* ofCode, |
|
const ZSTD_CCtx_params* cctxParams, |
|
void* dst, size_t dstCapacity, |
|
const int bmi2, int writeEntropy, int* entropyWritten) |
|
{ |
|
const int longOffsets = cctxParams->cParams.windowLog > STREAM_ACCUMULATOR_MIN; |
|
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); |
|
|
|
*entropyWritten = 0; |
|
/* 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 (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)); |
|
ZSTD_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, "ZSTD_encodeSequences failed"); |
|
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. |
|
*/ |
|
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION |
|
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; |
|
} |
|
#endif |
|
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. |
|
*/ |
|
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION |
|
if (op-seqHead < 4) { |
|
DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.4.0 by emitting " |
|
"an uncompressed block when sequences are < 4 bytes"); |
|
return 0; |
|
} |
|
#endif |
|
|
|
*entropyWritten = 1; |
|
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 writeLitEntropy, int writeSeqEntropy, |
|
int* litEntropyWritten, int* seqEntropyWritten, |
|
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, writeLitEntropy=%d, writeSeqEntropy=%d, lastBlock=%d)", |
|
litSize, nbSeq, writeLitEntropy, writeSeqEntropy, lastBlock); |
|
{ size_t cLitSize = ZSTD_compressSubBlock_literal((const HUF_CElt*)entropy->huf.CTable, |
|
&entropyMetadata->hufMetadata, literals, litSize, |
|
op, oend-op, bmi2, writeLitEntropy, litEntropyWritten); |
|
FORWARD_IF_ERROR(cLitSize, "ZSTD_compressSubBlock_literal failed"); |
|
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, writeSeqEntropy, seqEntropyWritten); |
|
FORWARD_IF_ERROR(cSeqSize, "ZSTD_compressSubBlock_sequences failed"); |
|
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 || hufMetadata->hType == set_repeat) { |
|
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, U32 defaultMax, |
|
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) { |
|
/* We selected this encoding type, so it must be valid. */ |
|
assert(max <= defaultMax); |
|
cSymbolTypeSizeEstimateInBits = max <= defaultMax |
|
? ZSTD_crossEntropyCost(defaultNorm, defaultNormLog, countWksp, max) |
|
: ERROR(GENERIC); |
|
} 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, DefaultMaxOff, |
|
workspace, wkspSize); |
|
cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->llType, llCodeTable, MaxLL, |
|
nbSeq, fseTables->litlengthCTable, LL_bits, |
|
LL_defaultNorm, LL_defaultNormLog, MaxLL, |
|
workspace, wkspSize); |
|
cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->mlType, mlCodeTable, MaxML, |
|
nbSeq, fseTables->matchlengthCTable, ML_bits, |
|
ML_defaultNorm, ML_defaultNormLog, MaxML, |
|
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 writeLitEntropy, int writeSeqEntropy) { |
|
size_t cSizeEstimate = 0; |
|
cSizeEstimate += ZSTD_estimateSubBlockSize_literal(literals, litSize, |
|
&entropy->huf, &entropyMetadata->hufMetadata, |
|
workspace, wkspSize, writeLitEntropy); |
|
cSizeEstimate += ZSTD_estimateSubBlockSize_sequences(ofCodeTable, llCodeTable, mlCodeTable, |
|
nbSeq, &entropy->fse, &entropyMetadata->fseMetadata, |
|
workspace, wkspSize, writeSeqEntropy); |
|
return cSizeEstimate + ZSTD_blockHeaderSize; |
|
} |
|
|
|
static int ZSTD_needSequenceEntropyTables(ZSTD_fseCTablesMetadata_t const* fseMetadata) |
|
{ |
|
if (fseMetadata->llType == set_compressed || fseMetadata->llType == set_rle) |
|
return 1; |
|
if (fseMetadata->mlType == set_compressed || fseMetadata->mlType == set_rle) |
|
return 1; |
|
if (fseMetadata->ofType == set_compressed || fseMetadata->ofType == set_rle) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
/* 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_compressedBlockState_t* prevCBlock, |
|
ZSTD_compressedBlockState_t* nextCBlock, |
|
const ZSTD_entropyCTablesMetadata_t* entropyMetadata, |
|
const ZSTD_CCtx_params* cctxParams, |
|
void* dst, size_t dstCapacity, |
|
const void* src, size_t srcSize, |
|
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* ip = (BYTE const*)src; |
|
BYTE const* const iend = ip + srcSize; |
|
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 writeLitEntropy = entropyMetadata->hufMetadata.hType == set_compressed; |
|
int writeSeqEntropy = 1; |
|
int lastSequence = 0; |
|
|
|
DEBUGLOG(5, "ZSTD_compressSubBlock_multi (litSize=%u, nbSeq=%u)", |
|
(unsigned)(lend-lp), (unsigned)(send-sstart)); |
|
|
|
litSize = 0; |
|
seqCount = 0; |
|
do { |
|
size_t cBlockSizeEstimate = 0; |
|
if (sstart == send) { |
|
lastSequence = 1; |
|
} else { |
|
const seqDef* const sequence = sp + seqCount; |
|
lastSequence = sequence == send - 1; |
|
litSize += ZSTD_getSequenceLength(seqStorePtr, sequence).litLength; |
|
seqCount++; |
|
} |
|
if (lastSequence) { |
|
assert(lp <= lend); |
|
assert(litSize <= (size_t)(lend - lp)); |
|
litSize = (size_t)(lend - lp); |
|
} |
|
/* 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, |
|
&nextCBlock->entropy, entropyMetadata, |
|
workspace, wkspSize, writeLitEntropy, writeSeqEntropy); |
|
if (cBlockSizeEstimate > targetCBlockSize || lastSequence) { |
|
int litEntropyWritten = 0; |
|
int seqEntropyWritten = 0; |
|
const size_t decompressedSize = ZSTD_seqDecompressedSize(seqStorePtr, sp, seqCount, litSize, lastSequence); |
|
const size_t cSize = ZSTD_compressSubBlock(&nextCBlock->entropy, entropyMetadata, |
|
sp, seqCount, |
|
lp, litSize, |
|
llCodePtr, mlCodePtr, ofCodePtr, |
|
cctxParams, |
|
op, oend-op, |
|
bmi2, writeLitEntropy, writeSeqEntropy, |
|
&litEntropyWritten, &seqEntropyWritten, |
|
lastBlock && lastSequence); |
|
FORWARD_IF_ERROR(cSize, "ZSTD_compressSubBlock failed"); |
|
if (cSize > 0 && cSize < decompressedSize) { |
|
DEBUGLOG(5, "Committed the sub-block"); |
|
assert(ip + decompressedSize <= iend); |
|
ip += decompressedSize; |
|
sp += seqCount; |
|
lp += litSize; |
|
op += cSize; |
|
llCodePtr += seqCount; |
|
mlCodePtr += seqCount; |
|
ofCodePtr += seqCount; |
|
litSize = 0; |
|
seqCount = 0; |
|
/* Entropy only needs to be written once */ |
|
if (litEntropyWritten) { |
|
writeLitEntropy = 0; |
|
} |
|
if (seqEntropyWritten) { |
|
writeSeqEntropy = 0; |
|
} |
|
} |
|
} |
|
} while (!lastSequence); |
|
if (writeLitEntropy) { |
|
DEBUGLOG(5, "ZSTD_compressSubBlock_multi has literal entropy tables unwritten"); |
|
ZSTD_memcpy(&nextCBlock->entropy.huf, &prevCBlock->entropy.huf, sizeof(prevCBlock->entropy.huf)); |
|
} |
|
if (writeSeqEntropy && ZSTD_needSequenceEntropyTables(&entropyMetadata->fseMetadata)) { |
|
/* If we haven't written our entropy tables, then we've violated our contract and |
|
* must emit an uncompressed block. |
|
*/ |
|
DEBUGLOG(5, "ZSTD_compressSubBlock_multi has sequence entropy tables unwritten"); |
|
return 0; |
|
} |
|
if (ip < iend) { |
|
size_t const cSize = ZSTD_noCompressBlock(op, oend - op, ip, iend - ip, lastBlock); |
|
DEBUGLOG(5, "ZSTD_compressSubBlock_multi last sub-block uncompressed, %zu bytes", (size_t)(iend - ip)); |
|
FORWARD_IF_ERROR(cSize, "ZSTD_noCompressBlock failed"); |
|
assert(cSize != 0); |
|
op += cSize; |
|
/* We have to regenerate the repcodes because we've skipped some sequences */ |
|
if (sp < send) { |
|
seqDef const* seq; |
|
repcodes_t rep; |
|
ZSTD_memcpy(&rep, prevCBlock->rep, sizeof(rep)); |
|
for (seq = sstart; seq < sp; ++seq) { |
|
rep = ZSTD_updateRep(rep.rep, seq->offset - 1, ZSTD_getSequenceLength(seqStorePtr, seq).litLength == 0); |
|
} |
|
ZSTD_memcpy(nextCBlock->rep, &rep, sizeof(rep)); |
|
} |
|
} |
|
DEBUGLOG(5, "ZSTD_compressSubBlock_multi compressed"); |
|
return op-ostart; |
|
} |
|
|
|
size_t ZSTD_compressSuperBlock(ZSTD_CCtx* zc, |
|
void* dst, size_t dstCapacity, |
|
void const* src, size_t srcSize, |
|
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, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */), ""); |
|
|
|
return ZSTD_compressSubBlock_multi(&zc->seqStore, |
|
zc->blockState.prevCBlock, |
|
zc->blockState.nextCBlock, |
|
&entropyMetadata, |
|
&zc->appliedParams, |
|
dst, dstCapacity, |
|
src, srcSize, |
|
zc->bmi2, lastBlock, |
|
zc->entropyWorkspace, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */); |
|
}
|
|
|