--- /dev/null
- * Provides the size of compressed block from block header `src` */
+/*
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/* zstd_decompress_block :
+ * this module takes care of decompressing _compressed_ block */
+
+/*-*******************************************************
+* Dependencies
+*********************************************************/
+#include <string.h> /* memcpy, memmove, memset */
+#include "compiler.h" /* prefetch */
+#include "cpu.h" /* bmi2 */
+#include "mem.h" /* low level memory routines */
+#define FSE_STATIC_LINKING_ONLY
+#include "fse.h"
+#define HUF_STATIC_LINKING_ONLY
+#include "huf.h"
+#include "zstd_internal.h"
+#include "zstd_decompress_internal.h" /* ZSTD_DCtx */
+#include "zstd_ddict.h" /* ZSTD_DDictDictContent */
+#include "zstd_decompress_block.h"
+
+
+
+/*_*******************************************************
+* Memory operations
+**********************************************************/
+static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
+
+
+/*-*************************************************************
+ * Block decoding
+ ***************************************************************/
+
+/*! ZSTD_getcBlockSize() :
++ * Provides the size of compressed block from block header `src` */
+size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
+ blockProperties_t* bpPtr)
+{
+ if (srcSize < ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
+ { U32 const cBlockHeader = MEM_readLE24(src);
+ U32 const cSize = cBlockHeader >> 3;
+ bpPtr->lastBlock = cBlockHeader & 1;
+ bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3);
+ bpPtr->origSize = cSize; /* only useful for RLE */
+ if (bpPtr->blockType == bt_rle) return 1;
+ if (bpPtr->blockType == bt_reserved) return ERROR(corruption_detected);
+ return cSize;
+ }
+}
+
+
+/* Hidden declaration for fullbench */
+size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
+ const void* src, size_t srcSize);
+/*! ZSTD_decodeLiteralsBlock() :
+ * @return : nb of bytes read from src (< srcSize )
+ * note : symbol not declared but exposed for fullbench */
+size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
+ const void* src, size_t srcSize) /* note : srcSize < BLOCKSIZE */
+{
+ if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
+
+ { const BYTE* const istart = (const BYTE*) src;
+ symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3);
+
+ switch(litEncType)
+ {
+ case set_repeat:
+ if (dctx->litEntropy==0) return ERROR(dictionary_corrupted);
+ /* fall-through */
+
+ case set_compressed:
+ if (srcSize < 5) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for case 3 */
+ { size_t lhSize, litSize, litCSize;
+ U32 singleStream=0;
+ U32 const lhlCode = (istart[0] >> 2) & 3;
+ U32 const lhc = MEM_readLE32(istart);
+ switch(lhlCode)
+ {
+ case 0: case 1: default: /* note : default is impossible, since lhlCode into [0..3] */
+ /* 2 - 2 - 10 - 10 */
+ singleStream = !lhlCode;
+ lhSize = 3;
+ litSize = (lhc >> 4) & 0x3FF;
+ litCSize = (lhc >> 14) & 0x3FF;
+ break;
+ case 2:
+ /* 2 - 2 - 14 - 14 */
+ lhSize = 4;
+ litSize = (lhc >> 4) & 0x3FFF;
+ litCSize = lhc >> 18;
+ break;
+ case 3:
+ /* 2 - 2 - 18 - 18 */
+ lhSize = 5;
+ litSize = (lhc >> 4) & 0x3FFFF;
+ litCSize = (lhc >> 22) + (istart[4] << 10);
+ break;
+ }
+ if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected);
+ if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
+
+ /* prefetch huffman table if cold */
+ if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) {
+ PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable));
+ }
+
+ if (HUF_isError((litEncType==set_repeat) ?
+ ( singleStream ?
+ HUF_decompress1X_usingDTable_bmi2(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr, dctx->bmi2) :
+ HUF_decompress4X_usingDTable_bmi2(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr, dctx->bmi2) ) :
+ ( singleStream ?
+ HUF_decompress1X1_DCtx_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize,
+ dctx->workspace, sizeof(dctx->workspace), dctx->bmi2) :
+ HUF_decompress4X_hufOnly_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize,
+ dctx->workspace, sizeof(dctx->workspace), dctx->bmi2))))
+ return ERROR(corruption_detected);
+
+ dctx->litPtr = dctx->litBuffer;
+ dctx->litSize = litSize;
+ dctx->litEntropy = 1;
+ if (litEncType==set_compressed) dctx->HUFptr = dctx->entropy.hufTable;
+ memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
+ return litCSize + lhSize;
+ }
+
+ case set_basic:
+ { size_t litSize, lhSize;
+ U32 const lhlCode = ((istart[0]) >> 2) & 3;
+ switch(lhlCode)
+ {
+ case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
+ lhSize = 1;
+ litSize = istart[0] >> 3;
+ break;
+ case 1:
+ lhSize = 2;
+ litSize = MEM_readLE16(istart) >> 4;
+ break;
+ case 3:
+ lhSize = 3;
+ litSize = MEM_readLE24(istart) >> 4;
+ break;
+ }
+
+ if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */
+ if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
+ memcpy(dctx->litBuffer, istart+lhSize, litSize);
+ dctx->litPtr = dctx->litBuffer;
+ dctx->litSize = litSize;
+ memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
+ return lhSize+litSize;
+ }
+ /* direct reference into compressed stream */
+ dctx->litPtr = istart+lhSize;
+ dctx->litSize = litSize;
+ return lhSize+litSize;
+ }
+
+ case set_rle:
+ { U32 const lhlCode = ((istart[0]) >> 2) & 3;
+ size_t litSize, lhSize;
+ switch(lhlCode)
+ {
+ case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
+ lhSize = 1;
+ litSize = istart[0] >> 3;
+ break;
+ case 1:
+ lhSize = 2;
+ litSize = MEM_readLE16(istart) >> 4;
+ break;
+ case 3:
+ lhSize = 3;
+ litSize = MEM_readLE24(istart) >> 4;
+ if (srcSize<4) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */
+ break;
+ }
+ if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected);
+ memset(dctx->litBuffer, istart[lhSize], litSize + WILDCOPY_OVERLENGTH);
+ dctx->litPtr = dctx->litBuffer;
+ dctx->litSize = litSize;
+ return lhSize+1;
+ }
+ default:
+ return ERROR(corruption_detected); /* impossible */
+ }
+ }
+}
+
+/* Default FSE distribution tables.
+ * These are pre-calculated FSE decoding tables using default distributions as defined in specification :
+ * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#default-distributions
+ * They were generated programmatically with following method :
+ * - start from default distributions, present in /lib/common/zstd_internal.h
+ * - generate tables normally, using ZSTD_buildFSETable()
+ * - printout the content of tables
+ * - pretify output, report below, test with fuzzer to ensure it's correct */
+
+/* Default FSE distribution table for Literal Lengths */
+static const ZSTD_seqSymbol LL_defaultDTable[(1<<LL_DEFAULTNORMLOG)+1] = {
+ { 1, 1, 1, LL_DEFAULTNORMLOG}, /* header : fastMode, tableLog */
+ /* nextState, nbAddBits, nbBits, baseVal */
+ { 0, 0, 4, 0}, { 16, 0, 4, 0},
+ { 32, 0, 5, 1}, { 0, 0, 5, 3},
+ { 0, 0, 5, 4}, { 0, 0, 5, 6},
+ { 0, 0, 5, 7}, { 0, 0, 5, 9},
+ { 0, 0, 5, 10}, { 0, 0, 5, 12},
+ { 0, 0, 6, 14}, { 0, 1, 5, 16},
+ { 0, 1, 5, 20}, { 0, 1, 5, 22},
+ { 0, 2, 5, 28}, { 0, 3, 5, 32},
+ { 0, 4, 5, 48}, { 32, 6, 5, 64},
+ { 0, 7, 5, 128}, { 0, 8, 6, 256},
+ { 0, 10, 6, 1024}, { 0, 12, 6, 4096},
+ { 32, 0, 4, 0}, { 0, 0, 4, 1},
+ { 0, 0, 5, 2}, { 32, 0, 5, 4},
+ { 0, 0, 5, 5}, { 32, 0, 5, 7},
+ { 0, 0, 5, 8}, { 32, 0, 5, 10},
+ { 0, 0, 5, 11}, { 0, 0, 6, 13},
+ { 32, 1, 5, 16}, { 0, 1, 5, 18},
+ { 32, 1, 5, 22}, { 0, 2, 5, 24},
+ { 32, 3, 5, 32}, { 0, 3, 5, 40},
+ { 0, 6, 4, 64}, { 16, 6, 4, 64},
+ { 32, 7, 5, 128}, { 0, 9, 6, 512},
+ { 0, 11, 6, 2048}, { 48, 0, 4, 0},
+ { 16, 0, 4, 1}, { 32, 0, 5, 2},
+ { 32, 0, 5, 3}, { 32, 0, 5, 5},
+ { 32, 0, 5, 6}, { 32, 0, 5, 8},
+ { 32, 0, 5, 9}, { 32, 0, 5, 11},
+ { 32, 0, 5, 12}, { 0, 0, 6, 15},
+ { 32, 1, 5, 18}, { 32, 1, 5, 20},
+ { 32, 2, 5, 24}, { 32, 2, 5, 28},
+ { 32, 3, 5, 40}, { 32, 4, 5, 48},
+ { 0, 16, 6,65536}, { 0, 15, 6,32768},
+ { 0, 14, 6,16384}, { 0, 13, 6, 8192},
+}; /* LL_defaultDTable */
+
+/* Default FSE distribution table for Offset Codes */
+static const ZSTD_seqSymbol OF_defaultDTable[(1<<OF_DEFAULTNORMLOG)+1] = {
+ { 1, 1, 1, OF_DEFAULTNORMLOG}, /* header : fastMode, tableLog */
+ /* nextState, nbAddBits, nbBits, baseVal */
+ { 0, 0, 5, 0}, { 0, 6, 4, 61},
+ { 0, 9, 5, 509}, { 0, 15, 5,32765},
+ { 0, 21, 5,2097149}, { 0, 3, 5, 5},
+ { 0, 7, 4, 125}, { 0, 12, 5, 4093},
+ { 0, 18, 5,262141}, { 0, 23, 5,8388605},
+ { 0, 5, 5, 29}, { 0, 8, 4, 253},
+ { 0, 14, 5,16381}, { 0, 20, 5,1048573},
+ { 0, 2, 5, 1}, { 16, 7, 4, 125},
+ { 0, 11, 5, 2045}, { 0, 17, 5,131069},
+ { 0, 22, 5,4194301}, { 0, 4, 5, 13},
+ { 16, 8, 4, 253}, { 0, 13, 5, 8189},
+ { 0, 19, 5,524285}, { 0, 1, 5, 1},
+ { 16, 6, 4, 61}, { 0, 10, 5, 1021},
+ { 0, 16, 5,65533}, { 0, 28, 5,268435453},
+ { 0, 27, 5,134217725}, { 0, 26, 5,67108861},
+ { 0, 25, 5,33554429}, { 0, 24, 5,16777213},
+}; /* OF_defaultDTable */
+
+
+/* Default FSE distribution table for Match Lengths */
+static const ZSTD_seqSymbol ML_defaultDTable[(1<<ML_DEFAULTNORMLOG)+1] = {
+ { 1, 1, 1, ML_DEFAULTNORMLOG}, /* header : fastMode, tableLog */
+ /* nextState, nbAddBits, nbBits, baseVal */
+ { 0, 0, 6, 3}, { 0, 0, 4, 4},
+ { 32, 0, 5, 5}, { 0, 0, 5, 6},
+ { 0, 0, 5, 8}, { 0, 0, 5, 9},
+ { 0, 0, 5, 11}, { 0, 0, 6, 13},
+ { 0, 0, 6, 16}, { 0, 0, 6, 19},
+ { 0, 0, 6, 22}, { 0, 0, 6, 25},
+ { 0, 0, 6, 28}, { 0, 0, 6, 31},
+ { 0, 0, 6, 34}, { 0, 1, 6, 37},
+ { 0, 1, 6, 41}, { 0, 2, 6, 47},
+ { 0, 3, 6, 59}, { 0, 4, 6, 83},
+ { 0, 7, 6, 131}, { 0, 9, 6, 515},
+ { 16, 0, 4, 4}, { 0, 0, 4, 5},
+ { 32, 0, 5, 6}, { 0, 0, 5, 7},
+ { 32, 0, 5, 9}, { 0, 0, 5, 10},
+ { 0, 0, 6, 12}, { 0, 0, 6, 15},
+ { 0, 0, 6, 18}, { 0, 0, 6, 21},
+ { 0, 0, 6, 24}, { 0, 0, 6, 27},
+ { 0, 0, 6, 30}, { 0, 0, 6, 33},
+ { 0, 1, 6, 35}, { 0, 1, 6, 39},
+ { 0, 2, 6, 43}, { 0, 3, 6, 51},
+ { 0, 4, 6, 67}, { 0, 5, 6, 99},
+ { 0, 8, 6, 259}, { 32, 0, 4, 4},
+ { 48, 0, 4, 4}, { 16, 0, 4, 5},
+ { 32, 0, 5, 7}, { 32, 0, 5, 8},
+ { 32, 0, 5, 10}, { 32, 0, 5, 11},
+ { 0, 0, 6, 14}, { 0, 0, 6, 17},
+ { 0, 0, 6, 20}, { 0, 0, 6, 23},
+ { 0, 0, 6, 26}, { 0, 0, 6, 29},
+ { 0, 0, 6, 32}, { 0, 16, 6,65539},
+ { 0, 15, 6,32771}, { 0, 14, 6,16387},
+ { 0, 13, 6, 8195}, { 0, 12, 6, 4099},
+ { 0, 11, 6, 2051}, { 0, 10, 6, 1027},
+}; /* ML_defaultDTable */
+
+
+static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U32 nbAddBits)
+{
+ void* ptr = dt;
+ ZSTD_seqSymbol_header* const DTableH = (ZSTD_seqSymbol_header*)ptr;
+ ZSTD_seqSymbol* const cell = dt + 1;
+
+ DTableH->tableLog = 0;
+ DTableH->fastMode = 0;
+
+ cell->nbBits = 0;
+ cell->nextState = 0;
+ assert(nbAddBits < 255);
+ cell->nbAdditionalBits = (BYTE)nbAddBits;
+ cell->baseValue = baseValue;
+}
+
+
+/* ZSTD_buildFSETable() :
+ * generate FSE decoding table for one symbol (ll, ml or off) */
+void
+ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
+ const short* normalizedCounter, unsigned maxSymbolValue,
+ const U32* baseValue, const U32* nbAdditionalBits,
+ unsigned tableLog)
+{
+ ZSTD_seqSymbol* const tableDecode = dt+1;
+ U16 symbolNext[MaxSeq+1];
+
+ U32 const maxSV1 = maxSymbolValue + 1;
+ U32 const tableSize = 1 << tableLog;
+ U32 highThreshold = tableSize-1;
+
+ /* Sanity Checks */
+ assert(maxSymbolValue <= MaxSeq);
+ assert(tableLog <= MaxFSELog);
+
+ /* Init, lay down lowprob symbols */
+ { ZSTD_seqSymbol_header DTableH;
+ DTableH.tableLog = tableLog;
+ DTableH.fastMode = 1;
+ { S16 const largeLimit= (S16)(1 << (tableLog-1));
+ U32 s;
+ for (s=0; s<maxSV1; s++) {
+ if (normalizedCounter[s]==-1) {
+ tableDecode[highThreshold--].baseValue = s;
+ symbolNext[s] = 1;
+ } else {
+ if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0;
+ symbolNext[s] = normalizedCounter[s];
+ } } }
+ memcpy(dt, &DTableH, sizeof(DTableH));
+ }
+
+ /* Spread symbols */
+ { U32 const tableMask = tableSize-1;
+ U32 const step = FSE_TABLESTEP(tableSize);
+ U32 s, position = 0;
+ for (s=0; s<maxSV1; s++) {
+ int i;
+ for (i=0; i<normalizedCounter[s]; i++) {
+ tableDecode[position].baseValue = s;
+ position = (position + step) & tableMask;
+ while (position > highThreshold) position = (position + step) & tableMask; /* lowprob area */
+ } }
+ assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */
+ }
+
+ /* Build Decoding table */
+ { U32 u;
+ for (u=0; u<tableSize; u++) {
+ U32 const symbol = tableDecode[u].baseValue;
+ U32 const nextState = symbolNext[symbol]++;
+ tableDecode[u].nbBits = (BYTE) (tableLog - BIT_highbit32(nextState) );
+ tableDecode[u].nextState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize);
+ assert(nbAdditionalBits[symbol] < 255);
+ tableDecode[u].nbAdditionalBits = (BYTE)nbAdditionalBits[symbol];
+ tableDecode[u].baseValue = baseValue[symbol];
+ } }
+}
+
+
+/*! ZSTD_buildSeqTable() :
+ * @return : nb bytes read from src,
+ * or an error code if it fails */
+static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymbol** DTablePtr,
+ symbolEncodingType_e type, U32 max, U32 maxLog,
+ const void* src, size_t srcSize,
+ const U32* baseValue, const U32* nbAdditionalBits,
+ const ZSTD_seqSymbol* defaultTable, U32 flagRepeatTable,
+ int ddictIsCold, int nbSeq)
+{
+ switch(type)
+ {
+ case set_rle :
+ if (!srcSize) return ERROR(srcSize_wrong);
+ if ( (*(const BYTE*)src) > max) return ERROR(corruption_detected);
+ { U32 const symbol = *(const BYTE*)src;
+ U32 const baseline = baseValue[symbol];
+ U32 const nbBits = nbAdditionalBits[symbol];
+ ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits);
+ }
+ *DTablePtr = DTableSpace;
+ return 1;
+ case set_basic :
+ *DTablePtr = defaultTable;
+ return 0;
+ case set_repeat:
+ if (!flagRepeatTable) return ERROR(corruption_detected);
+ /* prefetch FSE table if used */
+ if (ddictIsCold && (nbSeq > 24 /* heuristic */)) {
+ const void* const pStart = *DTablePtr;
+ size_t const pSize = sizeof(ZSTD_seqSymbol) * (SEQSYMBOL_TABLE_SIZE(maxLog));
+ PREFETCH_AREA(pStart, pSize);
+ }
+ return 0;
+ case set_compressed :
+ { U32 tableLog;
+ S16 norm[MaxSeq+1];
+ size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
+ if (FSE_isError(headerSize)) return ERROR(corruption_detected);
+ if (tableLog > maxLog) return ERROR(corruption_detected);
+ ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog);
+ *DTablePtr = DTableSpace;
+ return headerSize;
+ }
+ default : /* impossible */
+ assert(0);
+ return ERROR(GENERIC);
+ }
+}
+
+size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
+ const void* src, size_t srcSize)
+{
+ const BYTE* const istart = (const BYTE* const)src;
+ const BYTE* const iend = istart + srcSize;
+ const BYTE* ip = istart;
+ int nbSeq;
+ DEBUGLOG(5, "ZSTD_decodeSeqHeaders");
+
+ /* check */
+ if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong);
+
+ /* SeqHead */
+ nbSeq = *ip++;
+ if (!nbSeq) {
+ *nbSeqPtr=0;
+ if (srcSize != 1) return ERROR(srcSize_wrong);
+ return 1;
+ }
+ if (nbSeq > 0x7F) {
+ if (nbSeq == 0xFF) {
+ if (ip+2 > iend) return ERROR(srcSize_wrong);
+ nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2;
+ } else {
+ if (ip >= iend) return ERROR(srcSize_wrong);
+ nbSeq = ((nbSeq-0x80)<<8) + *ip++;
+ }
+ }
+ *nbSeqPtr = nbSeq;
+
+ /* FSE table descriptors */
+ if (ip+4 > iend) return ERROR(srcSize_wrong); /* minimum possible size */
+ { symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6);
+ symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3);
+ symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3);
+ ip++;
+
+ /* Build DTables */
+ { size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr,
+ LLtype, MaxLL, LLFSELog,
+ ip, iend-ip,
+ LL_base, LL_bits,
+ LL_defaultDTable, dctx->fseEntropy,
+ dctx->ddictIsCold, nbSeq);
+ if (ZSTD_isError(llhSize)) return ERROR(corruption_detected);
+ ip += llhSize;
+ }
+
+ { size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr,
+ OFtype, MaxOff, OffFSELog,
+ ip, iend-ip,
+ OF_base, OF_bits,
+ OF_defaultDTable, dctx->fseEntropy,
+ dctx->ddictIsCold, nbSeq);
+ if (ZSTD_isError(ofhSize)) return ERROR(corruption_detected);
+ ip += ofhSize;
+ }
+
+ { size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr,
+ MLtype, MaxML, MLFSELog,
+ ip, iend-ip,
+ ML_base, ML_bits,
+ ML_defaultDTable, dctx->fseEntropy,
+ dctx->ddictIsCold, nbSeq);
+ if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected);
+ ip += mlhSize;
+ }
+ }
+
+ /* prefetch dictionary content */
+ if (dctx->ddictIsCold) {
+ size_t const dictSize = (const char*)dctx->prefixStart - (const char*)dctx->virtualStart;
+ size_t const psmin = MIN(dictSize, (size_t)(64*nbSeq) /* heuristic */ );
+ size_t const pSize = MIN(psmin, 128 KB /* protection */ );
+ const void* const pStart = (const char*)dctx->dictEnd - pSize;
+ PREFETCH_AREA(pStart, pSize);
+ dctx->ddictIsCold = 0;
+ }
+
+ return ip-istart;
+}
+
+
+typedef struct {
+ size_t litLength;
+ size_t matchLength;
+ size_t offset;
+ const BYTE* match;
+} seq_t;
+
+typedef struct {
+ size_t state;
+ const ZSTD_seqSymbol* table;
+} ZSTD_fseState;
+
+typedef struct {
+ BIT_DStream_t DStream;
+ ZSTD_fseState stateLL;
+ ZSTD_fseState stateOffb;
+ ZSTD_fseState stateML;
+ size_t prevOffset[ZSTD_REP_NUM];
+ const BYTE* prefixStart;
+ const BYTE* dictEnd;
+ size_t pos;
+} seqState_t;
+
+
+/* ZSTD_execSequenceLast7():
+ * exceptional case : decompress a match starting within last 7 bytes of output buffer.
+ * requires more careful checks, to ensure there is no overflow.
+ * performance does not matter though.
+ * note : this case is supposed to be never generated "naturally" by reference encoder,
+ * since in most cases it needs at least 8 bytes to look for a match.
+ * but it's allowed by the specification. */
+FORCE_NOINLINE
+size_t ZSTD_execSequenceLast7(BYTE* op,
+ BYTE* const oend, seq_t sequence,
+ const BYTE** litPtr, const BYTE* const litLimit,
+ const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
+{
+ BYTE* const oLitEnd = op + sequence.litLength;
+ size_t const sequenceLength = sequence.litLength + sequence.matchLength;
+ BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */
+ const BYTE* const iLitEnd = *litPtr + sequence.litLength;
+ const BYTE* match = oLitEnd - sequence.offset;
+
+ /* check */
+ if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must fit within dstBuffer */
+ if (iLitEnd > litLimit) return ERROR(corruption_detected); /* try to read beyond literal buffer */
+
+ /* copy literals */
+ while (op < oLitEnd) *op++ = *(*litPtr)++;
+
+ /* copy Match */
+ if (sequence.offset > (size_t)(oLitEnd - base)) {
+ /* offset beyond prefix */
+ if (sequence.offset > (size_t)(oLitEnd - vBase)) return ERROR(corruption_detected);
+ match = dictEnd - (base-match);
+ if (match + sequence.matchLength <= dictEnd) {
+ memmove(oLitEnd, match, sequence.matchLength);
+ return sequenceLength;
+ }
+ /* span extDict & currentPrefixSegment */
+ { size_t const length1 = dictEnd - match;
+ memmove(oLitEnd, match, length1);
+ op = oLitEnd + length1;
+ sequence.matchLength -= length1;
+ match = base;
+ } }
+ while (op < oMatchEnd) *op++ = *match++;
+ return sequenceLength;
+}
+
+
+HINT_INLINE
+size_t ZSTD_execSequence(BYTE* op,
+ BYTE* const oend, seq_t sequence,
+ const BYTE** litPtr, const BYTE* const litLimit,
+ const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
+{
+ BYTE* const oLitEnd = op + sequence.litLength;
+ size_t const sequenceLength = sequence.litLength + sequence.matchLength;
+ BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */
+ BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
+ const BYTE* const iLitEnd = *litPtr + sequence.litLength;
+ const BYTE* match = oLitEnd - sequence.offset;
+
+ /* check */
+ if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
+ if (iLitEnd > litLimit) return ERROR(corruption_detected); /* over-read beyond lit buffer */
+ if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd);
+
+ /* copy Literals */
+ ZSTD_copy8(op, *litPtr);
+ if (sequence.litLength > 8)
+ ZSTD_wildcopy(op+8, (*litPtr)+8, sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
+ op = oLitEnd;
+ *litPtr = iLitEnd; /* update for next sequence */
+
+ /* copy Match */
+ if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
+ /* offset beyond prefix -> go into extDict */
+ if (sequence.offset > (size_t)(oLitEnd - virtualStart))
+ return ERROR(corruption_detected);
+ match = dictEnd + (match - prefixStart);
+ if (match + sequence.matchLength <= dictEnd) {
+ memmove(oLitEnd, match, sequence.matchLength);
+ return sequenceLength;
+ }
+ /* span extDict & currentPrefixSegment */
+ { size_t const length1 = dictEnd - match;
+ memmove(oLitEnd, match, length1);
+ op = oLitEnd + length1;
+ sequence.matchLength -= length1;
+ match = prefixStart;
+ if (op > oend_w || sequence.matchLength < MINMATCH) {
+ U32 i;
+ for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i];
+ return sequenceLength;
+ }
+ } }
+ /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */
+
+ /* match within prefix */
+ if (sequence.offset < 8) {
+ /* close range match, overlap */
+ static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */
+ static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* subtracted */
+ int const sub2 = dec64table[sequence.offset];
+ op[0] = match[0];
+ op[1] = match[1];
+ op[2] = match[2];
+ op[3] = match[3];
+ match += dec32table[sequence.offset];
+ ZSTD_copy4(op+4, match);
+ match -= sub2;
+ } else {
+ ZSTD_copy8(op, match);
+ }
+ op += 8; match += 8;
+
+ if (oMatchEnd > oend-(16-MINMATCH)) {
+ if (op < oend_w) {
+ ZSTD_wildcopy(op, match, oend_w - op);
+ match += oend_w - op;
+ op = oend_w;
+ }
+ while (op < oMatchEnd) *op++ = *match++;
+ } else {
+ ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8); /* works even if matchLength < 8 */
+ }
+ return sequenceLength;
+}
+
+
+HINT_INLINE
+size_t ZSTD_execSequenceLong(BYTE* op,
+ BYTE* const oend, seq_t sequence,
+ const BYTE** litPtr, const BYTE* const litLimit,
+ const BYTE* const prefixStart, const BYTE* const dictStart, const BYTE* const dictEnd)
+{
+ BYTE* const oLitEnd = op + sequence.litLength;
+ size_t const sequenceLength = sequence.litLength + sequence.matchLength;
+ BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */
+ BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
+ const BYTE* const iLitEnd = *litPtr + sequence.litLength;
+ const BYTE* match = sequence.match;
+
+ /* check */
+ if (oMatchEnd > oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
+ if (iLitEnd > litLimit) return ERROR(corruption_detected); /* over-read beyond lit buffer */
+ if (oLitEnd > oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, dictStart, dictEnd);
+
+ /* copy Literals */
+ ZSTD_copy8(op, *litPtr); /* note : op <= oLitEnd <= oend_w == oend - 8 */
+ if (sequence.litLength > 8)
+ ZSTD_wildcopy(op+8, (*litPtr)+8, sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
+ op = oLitEnd;
+ *litPtr = iLitEnd; /* update for next sequence */
+
+ /* copy Match */
+ if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
+ /* offset beyond prefix */
+ if (sequence.offset > (size_t)(oLitEnd - dictStart)) return ERROR(corruption_detected);
+ if (match + sequence.matchLength <= dictEnd) {
+ memmove(oLitEnd, match, sequence.matchLength);
+ return sequenceLength;
+ }
+ /* span extDict & currentPrefixSegment */
+ { size_t const length1 = dictEnd - match;
+ memmove(oLitEnd, match, length1);
+ op = oLitEnd + length1;
+ sequence.matchLength -= length1;
+ match = prefixStart;
+ if (op > oend_w || sequence.matchLength < MINMATCH) {
+ U32 i;
+ for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i];
+ return sequenceLength;
+ }
+ } }
+ assert(op <= oend_w);
+ assert(sequence.matchLength >= MINMATCH);
+
+ /* match within prefix */
+ if (sequence.offset < 8) {
+ /* close range match, overlap */
+ static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */
+ static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* subtracted */
+ int const sub2 = dec64table[sequence.offset];
+ op[0] = match[0];
+ op[1] = match[1];
+ op[2] = match[2];
+ op[3] = match[3];
+ match += dec32table[sequence.offset];
+ ZSTD_copy4(op+4, match);
+ match -= sub2;
+ } else {
+ ZSTD_copy8(op, match);
+ }
+ op += 8; match += 8;
+
+ if (oMatchEnd > oend-(16-MINMATCH)) {
+ if (op < oend_w) {
+ ZSTD_wildcopy(op, match, oend_w - op);
+ match += oend_w - op;
+ op = oend_w;
+ }
+ while (op < oMatchEnd) *op++ = *match++;
+ } else {
+ ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8); /* works even if matchLength < 8 */
+ }
+ return sequenceLength;
+}
+
+static void
+ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt)
+{
+ const void* ptr = dt;
+ const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr;
+ DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
+ DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits",
+ (U32)DStatePtr->state, DTableH->tableLog);
+ BIT_reloadDStream(bitD);
+ DStatePtr->table = dt + 1;
+}
+
+FORCE_INLINE_TEMPLATE void
+ZSTD_updateFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD)
+{
+ ZSTD_seqSymbol const DInfo = DStatePtr->table[DStatePtr->state];
+ U32 const nbBits = DInfo.nbBits;
+ size_t const lowBits = BIT_readBits(bitD, nbBits);
+ DStatePtr->state = DInfo.nextState + lowBits;
+}
+
+/* We need to add at most (ZSTD_WINDOWLOG_MAX_32 - 1) bits to read the maximum
+ * offset bits. But we can only read at most (STREAM_ACCUMULATOR_MIN_32 - 1)
+ * bits before reloading. This value is the maximum number of bytes we read
+ * after reloading when we are decoding long offets.
+ */
+#define LONG_OFFSETS_MAX_EXTRA_BITS_32 \
+ (ZSTD_WINDOWLOG_MAX_32 > STREAM_ACCUMULATOR_MIN_32 \
+ ? ZSTD_WINDOWLOG_MAX_32 - STREAM_ACCUMULATOR_MIN_32 \
+ : 0)
+
+typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e;
+
+FORCE_INLINE_TEMPLATE seq_t
+ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
+{
+ seq_t seq;
+ U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits;
+ U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits;
+ U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits;
+ U32 const totalBits = llBits+mlBits+ofBits;
+ U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue;
+ U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue;
+ U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue;
+
+ /* sequence */
+ { size_t offset;
+ if (!ofBits)
+ offset = 0;
+ else {
+ ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
+ ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
+ assert(ofBits <= MaxOff);
+ if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) {
+ U32 const extraBits = ofBits - MIN(ofBits, 32 - seqState->DStream.bitsConsumed);
+ offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
+ BIT_reloadDStream(&seqState->DStream);
+ if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits);
+ assert(extraBits <= LONG_OFFSETS_MAX_EXTRA_BITS_32); /* to avoid another reload */
+ } else {
+ offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */
+ if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
+ }
+ }
+
+ if (ofBits <= 1) {
+ offset += (llBase==0);
+ if (offset) {
+ size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
+ temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */
+ if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
+ seqState->prevOffset[1] = seqState->prevOffset[0];
+ seqState->prevOffset[0] = offset = temp;
+ } else { /* offset == 0 */
+ offset = seqState->prevOffset[0];
+ }
+ } else {
+ seqState->prevOffset[2] = seqState->prevOffset[1];
+ seqState->prevOffset[1] = seqState->prevOffset[0];
+ seqState->prevOffset[0] = offset;
+ }
+ seq.offset = offset;
+ }
+
+ seq.matchLength = mlBase
+ + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/) : 0); /* <= 16 bits */
+ if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
+ BIT_reloadDStream(&seqState->DStream);
+ if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
+ BIT_reloadDStream(&seqState->DStream);
+ /* Ensure there are enough bits to read the rest of data in 64-bit mode. */
+ ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
+
+ seq.litLength = llBase
+ + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits/*>0*/) : 0); /* <= 16 bits */
+ if (MEM_32bits())
+ BIT_reloadDStream(&seqState->DStream);
+
+ DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u",
+ (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
+
+ /* ANS state update */
+ ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */
+ ZSTD_updateFseState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */
+ if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */
+ ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */
+
+ return seq;
+}
+
+FORCE_INLINE_TEMPLATE size_t
+ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
+ void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset)
+{
+ const BYTE* ip = (const BYTE*)seqStart;
+ const BYTE* const iend = ip + seqSize;
+ BYTE* const ostart = (BYTE* const)dst;
+ BYTE* const oend = ostart + maxDstSize;
+ BYTE* op = ostart;
+ const BYTE* litPtr = dctx->litPtr;
+ const BYTE* const litEnd = litPtr + dctx->litSize;
+ const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
+ const BYTE* const vBase = (const BYTE*) (dctx->virtualStart);
+ const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
+ DEBUGLOG(5, "ZSTD_decompressSequences_body");
+
+ /* Regen sequences */
+ if (nbSeq) {
+ seqState_t seqState;
+ dctx->fseEntropy = 1;
+ { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
+ CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend-ip), corruption_detected);
+ ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
+ ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
+ ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
+
+ for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) {
+ nbSeq--;
+ { seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
+ size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd);
+ DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
+ if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
+ op += oneSeqSize;
+ } }
+
+ /* check if reached exact end */
+ DEBUGLOG(5, "ZSTD_decompressSequences_body: after decode loop, remaining nbSeq : %i", nbSeq);
+ if (nbSeq) return ERROR(corruption_detected);
+ /* save reps for next block */
+ { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
+ }
+
+ /* last literal segment */
+ { size_t const lastLLSize = litEnd - litPtr;
+ if (lastLLSize > (size_t)(oend-op)) return ERROR(dstSize_tooSmall);
+ memcpy(op, litPtr, lastLLSize);
+ op += lastLLSize;
+ }
+
+ return op-ostart;
+}
+
+static size_t
+ZSTD_decompressSequences_default(ZSTD_DCtx* dctx,
+ void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset)
+{
+ return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
+}
+
+
+
+FORCE_INLINE_TEMPLATE seq_t
+ZSTD_decodeSequenceLong(seqState_t* seqState, ZSTD_longOffset_e const longOffsets)
+{
+ seq_t seq;
+ U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits;
+ U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits;
+ U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits;
+ U32 const totalBits = llBits+mlBits+ofBits;
+ U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue;
+ U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue;
+ U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue;
+
+ /* sequence */
+ { size_t offset;
+ if (!ofBits)
+ offset = 0;
+ else {
+ ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
+ ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
+ assert(ofBits <= MaxOff);
+ if (MEM_32bits() && longOffsets) {
+ U32 const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN_32-1);
+ offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
+ if (MEM_32bits() || extraBits) BIT_reloadDStream(&seqState->DStream);
+ if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits);
+ } else {
+ offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */
+ if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
+ }
+ }
+
+ if (ofBits <= 1) {
+ offset += (llBase==0);
+ if (offset) {
+ size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
+ temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */
+ if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
+ seqState->prevOffset[1] = seqState->prevOffset[0];
+ seqState->prevOffset[0] = offset = temp;
+ } else {
+ offset = seqState->prevOffset[0];
+ }
+ } else {
+ seqState->prevOffset[2] = seqState->prevOffset[1];
+ seqState->prevOffset[1] = seqState->prevOffset[0];
+ seqState->prevOffset[0] = offset;
+ }
+ seq.offset = offset;
+ }
+
+ seq.matchLength = mlBase + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0); /* <= 16 bits */
+ if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
+ BIT_reloadDStream(&seqState->DStream);
+ if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
+ BIT_reloadDStream(&seqState->DStream);
+ /* Verify that there is enough bits to read the rest of the data in 64-bit mode. */
+ ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
+
+ seq.litLength = llBase + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0); /* <= 16 bits */
+ if (MEM_32bits())
+ BIT_reloadDStream(&seqState->DStream);
+
+ { size_t const pos = seqState->pos + seq.litLength;
+ const BYTE* const matchBase = (seq.offset > pos) ? seqState->dictEnd : seqState->prefixStart;
+ seq.match = matchBase + pos - seq.offset; /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted.
+ * No consequence though : no memory access will occur, overly large offset will be detected in ZSTD_execSequenceLong() */
+ seqState->pos = pos + seq.matchLength;
+ }
+
+ /* ANS state update */
+ ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */
+ ZSTD_updateFseState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */
+ if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */
+ ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */
+
+ return seq;
+}
+
+FORCE_INLINE_TEMPLATE size_t
+ZSTD_decompressSequencesLong_body(
+ ZSTD_DCtx* dctx,
+ void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset)
+{
+ const BYTE* ip = (const BYTE*)seqStart;
+ const BYTE* const iend = ip + seqSize;
+ BYTE* const ostart = (BYTE* const)dst;
+ BYTE* const oend = ostart + maxDstSize;
+ BYTE* op = ostart;
+ const BYTE* litPtr = dctx->litPtr;
+ const BYTE* const litEnd = litPtr + dctx->litSize;
+ const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
+ const BYTE* const dictStart = (const BYTE*) (dctx->virtualStart);
+ const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
+
+ /* Regen sequences */
+ if (nbSeq) {
+#define STORED_SEQS 4
+#define STOSEQ_MASK (STORED_SEQS-1)
+#define ADVANCED_SEQS 4
+ seq_t sequences[STORED_SEQS];
+ int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS);
+ seqState_t seqState;
+ int seqNb;
+ dctx->fseEntropy = 1;
+ { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
+ seqState.prefixStart = prefixStart;
+ seqState.pos = (size_t)(op-prefixStart);
+ seqState.dictEnd = dictEnd;
+ CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend-ip), corruption_detected);
+ ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
+ ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
+ ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
+
+ /* prepare in advance */
+ for (seqNb=0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && (seqNb<seqAdvance); seqNb++) {
+ sequences[seqNb] = ZSTD_decodeSequenceLong(&seqState, isLongOffset);
+ }
+ if (seqNb<seqAdvance) return ERROR(corruption_detected);
+
+ /* decode and decompress */
+ for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (seqNb<nbSeq) ; seqNb++) {
+ seq_t const sequence = ZSTD_decodeSequenceLong(&seqState, isLongOffset);
+ size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[(seqNb-ADVANCED_SEQS) & STOSEQ_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd);
+ if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
+ PREFETCH(sequence.match); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */
+ sequences[seqNb&STOSEQ_MASK] = sequence;
+ op += oneSeqSize;
+ }
+ if (seqNb<nbSeq) return ERROR(corruption_detected);
+
+ /* finish queue */
+ seqNb -= seqAdvance;
+ for ( ; seqNb<nbSeq ; seqNb++) {
+ size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[seqNb&STOSEQ_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd);
+ if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
+ op += oneSeqSize;
+ }
+
+ /* save reps for next block */
+ { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
+#undef STORED_SEQS
+#undef STOSEQ_MASK
+#undef ADVANCED_SEQS
+ }
+
+ /* last literal segment */
+ { size_t const lastLLSize = litEnd - litPtr;
+ if (lastLLSize > (size_t)(oend-op)) return ERROR(dstSize_tooSmall);
+ memcpy(op, litPtr, lastLLSize);
+ op += lastLLSize;
+ }
+
+ return op-ostart;
+}
+
+static size_t
+ZSTD_decompressSequencesLong_default(ZSTD_DCtx* dctx,
+ void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset)
+{
+ return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
+}
+
+
+
+#if DYNAMIC_BMI2
+
+static TARGET_ATTRIBUTE("bmi2") size_t
+ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx,
+ void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset)
+{
+ return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
+}
+
+static TARGET_ATTRIBUTE("bmi2") size_t
+ZSTD_decompressSequencesLong_bmi2(ZSTD_DCtx* dctx,
+ void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset)
+{
+ return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
+}
+
+#endif
+
+typedef size_t (*ZSTD_decompressSequences_t)(
+ ZSTD_DCtx *dctx, void *dst, size_t maxDstSize,
+ const void *seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset);
+
+static size_t
+ZSTD_decompressSequences(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset)
+{
+ DEBUGLOG(5, "ZSTD_decompressSequences");
+#if DYNAMIC_BMI2
+ if (dctx->bmi2) {
+ return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
+ }
+#endif
+ return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
+}
+
+static size_t ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx,
+ void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize, int nbSeq,
+ const ZSTD_longOffset_e isLongOffset)
+{
+ DEBUGLOG(5, "ZSTD_decompressSequencesLong");
+#if DYNAMIC_BMI2
+ if (dctx->bmi2) {
+ return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
+ }
+#endif
+ return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
+}
+
+/* ZSTD_getLongOffsetsShare() :
+ * condition : offTable must be valid
+ * @return : "share" of long offsets (arbitrarily defined as > (1<<23))
+ * compared to maximum possible of (1<<OffFSELog) */
+static unsigned
+ZSTD_getLongOffsetsShare(const ZSTD_seqSymbol* offTable)
+{
+ const void* ptr = offTable;
+ U32 const tableLog = ((const ZSTD_seqSymbol_header*)ptr)[0].tableLog;
+ const ZSTD_seqSymbol* table = offTable + 1;
+ U32 const max = 1 << tableLog;
+ U32 u, total = 0;
+ DEBUGLOG(5, "ZSTD_getLongOffsetsShare: (tableLog=%u)", tableLog);
+
+ assert(max <= (1 << OffFSELog)); /* max not too large */
+ for (u=0; u<max; u++) {
+ if (table[u].nbAdditionalBits > 22) total += 1;
+ }
+
+ assert(tableLog <= OffFSELog);
+ total <<= (OffFSELog - tableLog); /* scale to OffFSELog */
+
+ return total;
+}
+
+
+size_t
+ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize, const int frame)
+{ /* blockType == blockCompressed */
+ const BYTE* ip = (const BYTE*)src;
+ /* isLongOffset must be true if there are long offsets.
+ * Offsets are long if they are larger than 2^STREAM_ACCUMULATOR_MIN.
+ * We don't expect that to be the case in 64-bit mode.
+ * In block mode, window size is not known, so we have to be conservative.
+ * (note: but it could be evaluated from current-lowLimit)
+ */
+ ZSTD_longOffset_e const isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (!frame || dctx->fParams.windowSize > (1ULL << STREAM_ACCUMULATOR_MIN)));
+ DEBUGLOG(5, "ZSTD_decompressBlock_internal (size : %u)", (U32)srcSize);
+
+ if (srcSize >= ZSTD_BLOCKSIZE_MAX) return ERROR(srcSize_wrong);
+
+ /* Decode literals section */
+ { size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize);
+ DEBUGLOG(5, "ZSTD_decodeLiteralsBlock : %u", (U32)litCSize);
+ if (ZSTD_isError(litCSize)) return litCSize;
+ ip += litCSize;
+ srcSize -= litCSize;
+ }
+
+ /* Build Decoding Tables */
+ { int nbSeq;
+ size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize);
+ if (ZSTD_isError(seqHSize)) return seqHSize;
+ ip += seqHSize;
+ srcSize -= seqHSize;
+
+ if ( (!frame || dctx->fParams.windowSize > (1<<24))
+ && (nbSeq>0) ) { /* could probably use a larger nbSeq limit */
+ U32 const shareLongOffsets = ZSTD_getLongOffsetsShare(dctx->OFTptr);
+ U32 const minShare = MEM_64bits() ? 7 : 20; /* heuristic values, correspond to 2.73% and 7.81% */
+ if (shareLongOffsets >= minShare)
+ return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
+ }
+
+ return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
+ }
+}
+
+
+size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize)
+{
+ size_t dSize;
+ ZSTD_checkContinuity(dctx, dst);
+ dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 0);
+ dctx->previousDstEnd = (char*)dst + dSize;
+ return dSize;
+}
projects / thirdparty / zstd.git / commitdiff
