| 1 | |
| 2 | |
| 3 | * Copyright (c) Meta Platforms, Inc. and affiliates.
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| 4 | * All rights reserved.
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| 5 | *
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| 6 | * This source code is licensed under both the BSD-style license (found in the
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| 7 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found
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| 8 | * in the COPYING file in the root directory of this source tree).
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| 9 | * You may select, at your option, one of the above-listed licenses.
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| 10 |
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| 11 |
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| 12 | |
| 13 | * this module takes care of decompressing _compressed_ block
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| 14 |
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| 15 | |
| 16 | * Dependencies
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| 17 | ********************************************************
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| 18 | #include "../common/zstd_deps.h"
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| 19 | #include "../common/compiler.h"
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| 20 | #include "../common/cpu.h"
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| 21 | #include "../common/mem.h"
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| 22 | #define FSE_STATIC_LINKING_ONLY
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| 23 | #include "../common/fse.h"
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| 24 | #include "../common/huf.h"
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| 25 | #include "../common/zstd_internal.h"
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| 26 | #include "zstd_decompress_internal.h"
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| 27 | #include "zstd_ddict.h"
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| 28 | #include "zstd_decompress_block.h"
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| 29 | #include "../common/bits.h"
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| 30 |
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| 31 | |
| 32 | * Macros
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| 33 | *********************************************************
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| 34 |
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| 35 | |
| 36 | * ZSTD_decompressSequences implementations. You can't force in both directions
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| 37 | * at the same time.
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| 38 |
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| 39 | #if defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
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| 40 | defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
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| 41 | #error "Cannot force the use of the short and the long ZSTD_decompressSequences variants!"
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| 42 | #endif
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| 43 |
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| 44 |
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| 45 | |
| 46 | * Memory operations
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| 47 | *********************************************************
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| 48 | static void ZSTD_copy4(void* dst, const void* src) { ZSTD_memcpy(dst, src, 4); }
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| 49 |
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| 50 |
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| 51 | |
| 52 | * Block decoding
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| 53 | **************************************************************
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| 54 |
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| 55 | static size_t ZSTD_blockSizeMax(ZSTD_DCtx const* dctx)
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| 56 | {
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| 57 | size_t const blockSizeMax = dctx->isFrameDecompression ? dctx->fParams.blockSizeMax : ZSTD_BLOCKSIZE_MAX;
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| 58 | assert(blockSizeMax <= ZSTD_BLOCKSIZE_MAX);
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| 59 | return blockSizeMax;
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| 60 | }
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| 61 |
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| 62 | |
| 63 | * Provides the size of compressed block from block header `src`
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| 64 | size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
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| 65 | blockProperties_t* bpPtr)
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| 66 | {
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| 67 | RETURN_ERROR_IF(srcSize < ZSTD_blockHeaderSize, srcSize_wrong, "");
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| 68 |
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| 69 | { U32 const cBlockHeader = MEM_readLE24(src);
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| 70 | U32 const cSize = cBlockHeader >> 3;
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| 71 | bpPtr->lastBlock = cBlockHeader & 1;
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| 72 | bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3);
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| 73 | bpPtr->origSize = cSize;
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| 74 | if (bpPtr->blockType == bt_rle) return 1;
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| 75 | RETURN_ERROR_IF(bpPtr->blockType == bt_reserved, corruption_detected, "");
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| 76 | return cSize;
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| 77 | }
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| 78 | }
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| 79 |
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| 80 |
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| 81 | static void ZSTD_allocateLiteralsBuffer(ZSTD_DCtx* dctx, void* const dst, const size_t dstCapacity, const size_t litSize,
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| 82 | const streaming_operation streaming, const size_t expectedWriteSize, const unsigned splitImmediately)
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| 83 | {
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| 84 | size_t const blockSizeMax = ZSTD_blockSizeMax(dctx);
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| 85 | assert(litSize <= blockSizeMax);
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| 86 | assert(dctx->isFrameDecompression || streaming == not_streaming);
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| 87 | assert(expectedWriteSize <= blockSizeMax);
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| 88 | if (streaming == not_streaming && dstCapacity > blockSizeMax + WILDCOPY_OVERLENGTH + litSize + WILDCOPY_OVERLENGTH) {
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| 89 | |
| 90 | * of the current block. We don't need to worry about overwriting the
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| 91 | * extDict of our window, because it doesn't exist.
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| 92 | * So if we have space after the end of the block, just put it there.
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| 93 |
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| 94 | dctx->litBuffer = (BYTE*)dst + blockSizeMax + WILDCOPY_OVERLENGTH;
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| 95 | dctx->litBufferEnd = dctx->litBuffer + litSize;
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| 96 | dctx->litBufferLocation = ZSTD_in_dst;
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| 97 | } else if (litSize <= ZSTD_LITBUFFEREXTRASIZE) {
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| 98 | |
| 99 | * having to split the literals.
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| 100 |
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| 101 | dctx->litBuffer = dctx->litExtraBuffer;
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| 102 | dctx->litBufferEnd = dctx->litBuffer + litSize;
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| 103 | dctx->litBufferLocation = ZSTD_not_in_dst;
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| 104 | } else {
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| 105 | assert(blockSizeMax > ZSTD_LITBUFFEREXTRASIZE);
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| 106 | |
| 107 | * buffer. We fill the extra lit buffer with the tail of the literals,
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| 108 | * and put the rest of the literals at the end of the block, with
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| 109 | * WILDCOPY_OVERLENGTH of buffer room to allow for overreads.
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| 110 | * This MUST not write more than our maxBlockSize beyond dst, because in
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| 111 | * streaming mode, that could overwrite part of our extDict window.
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| 112 |
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| 113 | if (splitImmediately) {
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| 114 |
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| 115 | dctx->litBuffer = (BYTE*)dst + expectedWriteSize - litSize + ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH;
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| 116 | dctx->litBufferEnd = dctx->litBuffer + litSize - ZSTD_LITBUFFEREXTRASIZE;
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| 117 | } else {
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| 118 |
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| 119 | dctx->litBuffer = (BYTE*)dst + expectedWriteSize - litSize;
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| 120 | dctx->litBufferEnd = (BYTE*)dst + expectedWriteSize;
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| 121 | }
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| 122 | dctx->litBufferLocation = ZSTD_split;
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| 123 | assert(dctx->litBufferEnd <= (BYTE*)dst + expectedWriteSize);
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| 124 | }
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| 125 | }
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| 126 |
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| 127 | |
| 128 | * Where it is possible to do so without being stomped by the output during decompression, the literals block will be stored
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| 129 | * in the dstBuffer. If there is room to do so, it will be stored in full in the excess dst space after where the current
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| 130 | * block will be output. Otherwise it will be stored at the end of the current dst blockspace, with a small portion being
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| 131 | * stored in dctx->litExtraBuffer to help keep it "ahead" of the current output write.
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| 132 | *
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| 133 | * @return : nb of bytes read from src (< srcSize )
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| 134 | * note : symbol not declared but exposed for fullbench
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| 135 | static size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
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| 136 | const void* src, size_t srcSize,
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| 137 | void* dst, size_t dstCapacity, const streaming_operation streaming)
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| 138 | {
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| 139 | DEBUGLOG(5, "ZSTD_decodeLiteralsBlock");
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| 140 | RETURN_ERROR_IF(srcSize < MIN_CBLOCK_SIZE, corruption_detected, "");
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| 141 |
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| 142 | { const BYTE* const istart = (const BYTE*) src;
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| 143 | SymbolEncodingType_e const litEncType = (SymbolEncodingType_e)(istart[0] & 3);
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| 144 | size_t const blockSizeMax = ZSTD_blockSizeMax(dctx);
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| 145 |
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| 146 | switch(litEncType)
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| 147 | {
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| 148 | case set_repeat:
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| 149 | DEBUGLOG(5, "set_repeat flag : re-using stats from previous compressed literals block");
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| 150 | RETURN_ERROR_IF(dctx->litEntropy==0, dictionary_corrupted, "");
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| 151 | ZSTD_FALLTHROUGH;
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| 152 |
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| 153 | case set_compressed:
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| 154 | RETURN_ERROR_IF(srcSize < 5, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need up to 5 for case 3");
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| 155 | { size_t lhSize, litSize, litCSize;
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| 156 | U32 singleStream=0;
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| 157 | U32 const lhlCode = (istart[0] >> 2) & 3;
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| 158 | U32 const lhc = MEM_readLE32(istart);
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| 159 | size_t hufSuccess;
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| 160 | size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity);
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| 161 | int const flags = 0
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| 162 | | (ZSTD_DCtx_get_bmi2(dctx) ? HUF_flags_bmi2 : 0)
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| 163 | | (dctx->disableHufAsm ? HUF_flags_disableAsm : 0);
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| 164 | switch(lhlCode)
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| 165 | {
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| 166 | case 0: case 1: default:
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| 167 |
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| 168 | singleStream = !lhlCode;
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| 169 | lhSize = 3;
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| 170 | litSize = (lhc >> 4) & 0x3FF;
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| 171 | litCSize = (lhc >> 14) & 0x3FF;
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| 172 | break;
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| 173 | case 2:
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| 174 |
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| 175 | lhSize = 4;
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| 176 | litSize = (lhc >> 4) & 0x3FFF;
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| 177 | litCSize = lhc >> 18;
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| 178 | break;
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| 179 | case 3:
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| 180 |
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| 181 | lhSize = 5;
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| 182 | litSize = (lhc >> 4) & 0x3FFFF;
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| 183 | litCSize = (lhc >> 22) + ((size_t)istart[4] << 10);
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| 184 | break;
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| 185 | }
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| 186 | RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled");
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| 187 | RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, "");
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| 188 | if (!singleStream)
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| 189 | RETURN_ERROR_IF(litSize < MIN_LITERALS_FOR_4_STREAMS, literals_headerWrong,
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| 190 | "Not enough literals (%zu) for the 4-streams mode (min %u)",
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| 191 | litSize, MIN_LITERALS_FOR_4_STREAMS);
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| 192 | RETURN_ERROR_IF(litCSize + lhSize > srcSize, corruption_detected, "");
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| 193 | RETURN_ERROR_IF(expectedWriteSize < litSize , dstSize_tooSmall, "");
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| 194 | ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 0);
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| 195 |
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| 196 |
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| 197 | if (dctx->ddictIsCold && (litSize > 768 )) {
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| 198 | PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable));
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| 199 | }
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| 200 |
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| 201 | if (litEncType==set_repeat) {
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| 202 | if (singleStream) {
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| 203 | hufSuccess = HUF_decompress1X_usingDTable(
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| 204 | dctx->litBuffer, litSize, istart+lhSize, litCSize,
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| 205 | dctx->HUFptr, flags);
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| 206 | } else {
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| 207 | assert(litSize >= MIN_LITERALS_FOR_4_STREAMS);
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| 208 | hufSuccess = HUF_decompress4X_usingDTable(
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| 209 | dctx->litBuffer, litSize, istart+lhSize, litCSize,
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| 210 | dctx->HUFptr, flags);
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| 211 | }
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| 212 | } else {
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| 213 | if (singleStream) {
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| 214 | #if defined(HUF_FORCE_DECOMPRESS_X2)
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| 215 | hufSuccess = HUF_decompress1X_DCtx_wksp(
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| 216 | dctx->entropy.hufTable, dctx->litBuffer, litSize,
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| 217 | istart+lhSize, litCSize, dctx->workspace,
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| 218 | sizeof(dctx->workspace), flags);
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| 219 | #else
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| 220 | hufSuccess = HUF_decompress1X1_DCtx_wksp(
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| 221 | dctx->entropy.hufTable, dctx->litBuffer, litSize,
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| 222 | istart+lhSize, litCSize, dctx->workspace,
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| 223 | sizeof(dctx->workspace), flags);
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| 224 | #endif
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| 225 | } else {
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| 226 | hufSuccess = HUF_decompress4X_hufOnly_wksp(
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| 227 | dctx->entropy.hufTable, dctx->litBuffer, litSize,
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| 228 | istart+lhSize, litCSize, dctx->workspace,
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| 229 | sizeof(dctx->workspace), flags);
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| 230 | }
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| 231 | }
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| 232 | if (dctx->litBufferLocation == ZSTD_split)
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| 233 | {
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| 234 | assert(litSize > ZSTD_LITBUFFEREXTRASIZE);
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| 235 | ZSTD_memcpy(dctx->litExtraBuffer, dctx->litBufferEnd - ZSTD_LITBUFFEREXTRASIZE, ZSTD_LITBUFFEREXTRASIZE);
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| 236 | ZSTD_memmove(dctx->litBuffer + ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH, dctx->litBuffer, litSize - ZSTD_LITBUFFEREXTRASIZE);
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| 237 | dctx->litBuffer += ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH;
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| 238 | dctx->litBufferEnd -= WILDCOPY_OVERLENGTH;
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| 239 | assert(dctx->litBufferEnd <= (BYTE*)dst + blockSizeMax);
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| 240 | }
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| 241 |
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| 242 | RETURN_ERROR_IF(HUF_isError(hufSuccess), corruption_detected, "");
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| 243 |
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| 244 | dctx->litPtr = dctx->litBuffer;
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| 245 | dctx->litSize = litSize;
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| 246 | dctx->litEntropy = 1;
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| 247 | if (litEncType==set_compressed) dctx->HUFptr = dctx->entropy.hufTable;
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| 248 | return litCSize + lhSize;
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| 249 | }
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| 250 |
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| 251 | case set_basic:
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| 252 | { size_t litSize, lhSize;
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| 253 | U32 const lhlCode = ((istart[0]) >> 2) & 3;
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| 254 | size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity);
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| 255 | switch(lhlCode)
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| 256 | {
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| 257 | case 0: case 2: default:
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| 258 | lhSize = 1;
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| 259 | litSize = istart[0] >> 3;
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| 260 | break;
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| 261 | case 1:
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| 262 | lhSize = 2;
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| 263 | litSize = MEM_readLE16(istart) >> 4;
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| 264 | break;
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| 265 | case 3:
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| 266 | lhSize = 3;
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| 267 | RETURN_ERROR_IF(srcSize<3, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize = 3");
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| 268 | litSize = MEM_readLE24(istart) >> 4;
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| 269 | break;
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| 270 | }
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| 271 |
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| 272 | RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled");
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| 273 | RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, "");
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| 274 | RETURN_ERROR_IF(expectedWriteSize < litSize, dstSize_tooSmall, "");
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| 275 | ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 1);
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| 276 | if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) {
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| 277 | RETURN_ERROR_IF(litSize+lhSize > srcSize, corruption_detected, "");
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| 278 | if (dctx->litBufferLocation == ZSTD_split)
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| 279 | {
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| 280 | ZSTD_memcpy(dctx->litBuffer, istart + lhSize, litSize - ZSTD_LITBUFFEREXTRASIZE);
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| 281 | ZSTD_memcpy(dctx->litExtraBuffer, istart + lhSize + litSize - ZSTD_LITBUFFEREXTRASIZE, ZSTD_LITBUFFEREXTRASIZE);
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| 282 | }
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| 283 | else
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| 284 | {
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| 285 | ZSTD_memcpy(dctx->litBuffer, istart + lhSize, litSize);
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| 286 | }
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| 287 | dctx->litPtr = dctx->litBuffer;
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| 288 | dctx->litSize = litSize;
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| 289 | return lhSize+litSize;
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| 290 | }
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| 291 |
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| 292 | dctx->litPtr = istart+lhSize;
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| 293 | dctx->litSize = litSize;
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| 294 | dctx->litBufferEnd = dctx->litPtr + litSize;
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| 295 | dctx->litBufferLocation = ZSTD_not_in_dst;
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| 296 | return lhSize+litSize;
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| 297 | }
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| 298 |
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| 299 | case set_rle:
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| 300 | { U32 const lhlCode = ((istart[0]) >> 2) & 3;
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| 301 | size_t litSize, lhSize;
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| 302 | size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity);
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| 303 | switch(lhlCode)
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| 304 | {
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| 305 | case 0: case 2: default:
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| 306 | lhSize = 1;
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| 307 | litSize = istart[0] >> 3;
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| 308 | break;
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| 309 | case 1:
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| 310 | lhSize = 2;
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| 311 | RETURN_ERROR_IF(srcSize<3, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize+1 = 3");
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| 312 | litSize = MEM_readLE16(istart) >> 4;
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| 313 | break;
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| 314 | case 3:
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| 315 | lhSize = 3;
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| 316 | RETURN_ERROR_IF(srcSize<4, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize+1 = 4");
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| 317 | litSize = MEM_readLE24(istart) >> 4;
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| 318 | break;
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| 319 | }
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| 320 | RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled");
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| 321 | RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, "");
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| 322 | RETURN_ERROR_IF(expectedWriteSize < litSize, dstSize_tooSmall, "");
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| 323 | ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 1);
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| 324 | if (dctx->litBufferLocation == ZSTD_split)
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| 325 | {
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| 326 | ZSTD_memset(dctx->litBuffer, istart[lhSize], litSize - ZSTD_LITBUFFEREXTRASIZE);
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| 327 | ZSTD_memset(dctx->litExtraBuffer, istart[lhSize], ZSTD_LITBUFFEREXTRASIZE);
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| 328 | }
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| 329 | else
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| 330 | {
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| 331 | ZSTD_memset(dctx->litBuffer, istart[lhSize], litSize);
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| 332 | }
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| 333 | dctx->litPtr = dctx->litBuffer;
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| 334 | dctx->litSize = litSize;
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| 335 | return lhSize+1;
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| 336 | }
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| 337 | default:
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| 338 | RETURN_ERROR(corruption_detected, "impossible");
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| 339 | }
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| 340 | }
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| 341 | }
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| 342 |
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| 343 |
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| 344 | size_t ZSTD_decodeLiteralsBlock_wrapper(ZSTD_DCtx* dctx,
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| 345 | const void* src, size_t srcSize,
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| 346 | void* dst, size_t dstCapacity);
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| 347 | size_t ZSTD_decodeLiteralsBlock_wrapper(ZSTD_DCtx* dctx,
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| 348 | const void* src, size_t srcSize,
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| 349 | void* dst, size_t dstCapacity)
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| 350 | {
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| 351 | dctx->isFrameDecompression = 0;
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| 352 | return ZSTD_decodeLiteralsBlock(dctx, src, srcSize, dst, dstCapacity, not_streaming);
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| 353 | }
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| 354 |
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| 355 | |
| 356 | * These are pre-calculated FSE decoding tables using default distributions as defined in specification :
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| 357 | * https://github.com/facebook/zstd/blob/release/doc/zstd_compression_format.md#default-distributions
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| 358 | * They were generated programmatically with following method :
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| 359 | * - start from default distributions, present in /lib/common/zstd_internal.h
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| 360 | * - generate tables normally, using ZSTD_buildFSETable()
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| 361 | * - printout the content of tables
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| 362 | * - prettify output, report below, test with fuzzer to ensure it's correct
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| 363 |
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| 364 |
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| 365 | static const ZSTD_seqSymbol LL_defaultDTable[(1<<LL_DEFAULTNORMLOG)+1] = {
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| 366 | { 1, 1, 1, LL_DEFAULTNORMLOG},
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| 367 |
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| 368 | { 0, 0, 4, 0}, { 16, 0, 4, 0},
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| 369 | { 32, 0, 5, 1}, { 0, 0, 5, 3},
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| 370 | { 0, 0, 5, 4}, { 0, 0, 5, 6},
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| 371 | { 0, 0, 5, 7}, { 0, 0, 5, 9},
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| 372 | { 0, 0, 5, 10}, { 0, 0, 5, 12},
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| 373 | { 0, 0, 6, 14}, { 0, 1, 5, 16},
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| 374 | { 0, 1, 5, 20}, { 0, 1, 5, 22},
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| 375 | { 0, 2, 5, 28}, { 0, 3, 5, 32},
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| 376 | { 0, 4, 5, 48}, { 32, 6, 5, 64},
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| 377 | { 0, 7, 5, 128}, { 0, 8, 6, 256},
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| 378 | { 0, 10, 6, 1024}, { 0, 12, 6, 4096},
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| 379 | { 32, 0, 4, 0}, { 0, 0, 4, 1},
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| 380 | { 0, 0, 5, 2}, { 32, 0, 5, 4},
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| 381 | { 0, 0, 5, 5}, { 32, 0, 5, 7},
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| 382 | { 0, 0, 5, 8}, { 32, 0, 5, 10},
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| 383 | { 0, 0, 5, 11}, { 0, 0, 6, 13},
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| 384 | { 32, 1, 5, 16}, { 0, 1, 5, 18},
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| 385 | { 32, 1, 5, 22}, { 0, 2, 5, 24},
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| 386 | { 32, 3, 5, 32}, { 0, 3, 5, 40},
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| 387 | { 0, 6, 4, 64}, { 16, 6, 4, 64},
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| 388 | { 32, 7, 5, 128}, { 0, 9, 6, 512},
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| 389 | { 0, 11, 6, 2048}, { 48, 0, 4, 0},
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| 390 | { 16, 0, 4, 1}, { 32, 0, 5, 2},
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| 391 | { 32, 0, 5, 3}, { 32, 0, 5, 5},
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| 392 | { 32, 0, 5, 6}, { 32, 0, 5, 8},
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| 393 | { 32, 0, 5, 9}, { 32, 0, 5, 11},
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| 394 | { 32, 0, 5, 12}, { 0, 0, 6, 15},
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| 395 | { 32, 1, 5, 18}, { 32, 1, 5, 20},
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| 396 | { 32, 2, 5, 24}, { 32, 2, 5, 28},
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| 397 | { 32, 3, 5, 40}, { 32, 4, 5, 48},
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| 398 | { 0, 16, 6,65536}, { 0, 15, 6,32768},
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| 399 | { 0, 14, 6,16384}, { 0, 13, 6, 8192},
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| 400 | };
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| 401 |
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| 402 |
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| 403 | static const ZSTD_seqSymbol OF_defaultDTable[(1<<OF_DEFAULTNORMLOG)+1] = {
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| 404 | { 1, 1, 1, OF_DEFAULTNORMLOG},
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| 405 |
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| 406 | { 0, 0, 5, 0}, { 0, 6, 4, 61},
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| 407 | { 0, 9, 5, 509}, { 0, 15, 5,32765},
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| 408 | { 0, 21, 5,2097149}, { 0, 3, 5, 5},
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| 409 | { 0, 7, 4, 125}, { 0, 12, 5, 4093},
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| 410 | { 0, 18, 5,262141}, { 0, 23, 5,8388605},
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| 411 | { 0, 5, 5, 29}, { 0, 8, 4, 253},
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| 412 | { 0, 14, 5,16381}, { 0, 20, 5,1048573},
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| 413 | { 0, 2, 5, 1}, { 16, 7, 4, 125},
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| 414 | { 0, 11, 5, 2045}, { 0, 17, 5,131069},
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| 415 | { 0, 22, 5,4194301}, { 0, 4, 5, 13},
|
| 416 | { 16, 8, 4, 253}, { 0, 13, 5, 8189},
|
| 417 | { 0, 19, 5,524285}, { 0, 1, 5, 1},
|
| 418 | { 16, 6, 4, 61}, { 0, 10, 5, 1021},
|
| 419 | { 0, 16, 5,65533}, { 0, 28, 5,268435453},
|
| 420 | { 0, 27, 5,134217725}, { 0, 26, 5,67108861},
|
| 421 | { 0, 25, 5,33554429}, { 0, 24, 5,16777213},
|
| 422 | };
|
| 423 |
|
| 424 |
|
| 425 |
|
| 426 | static const ZSTD_seqSymbol ML_defaultDTable[(1<<ML_DEFAULTNORMLOG)+1] = {
|
| 427 | { 1, 1, 1, ML_DEFAULTNORMLOG},
|
| 428 |
|
| 429 | { 0, 0, 6, 3}, { 0, 0, 4, 4},
|
| 430 | { 32, 0, 5, 5}, { 0, 0, 5, 6},
|
| 431 | { 0, 0, 5, 8}, { 0, 0, 5, 9},
|
| 432 | { 0, 0, 5, 11}, { 0, 0, 6, 13},
|
| 433 | { 0, 0, 6, 16}, { 0, 0, 6, 19},
|
| 434 | { 0, 0, 6, 22}, { 0, 0, 6, 25},
|
| 435 | { 0, 0, 6, 28}, { 0, 0, 6, 31},
|
| 436 | { 0, 0, 6, 34}, { 0, 1, 6, 37},
|
| 437 | { 0, 1, 6, 41}, { 0, 2, 6, 47},
|
| 438 | { 0, 3, 6, 59}, { 0, 4, 6, 83},
|
| 439 | { 0, 7, 6, 131}, { 0, 9, 6, 515},
|
| 440 | { 16, 0, 4, 4}, { 0, 0, 4, 5},
|
| 441 | { 32, 0, 5, 6}, { 0, 0, 5, 7},
|
| 442 | { 32, 0, 5, 9}, { 0, 0, 5, 10},
|
| 443 | { 0, 0, 6, 12}, { 0, 0, 6, 15},
|
| 444 | { 0, 0, 6, 18}, { 0, 0, 6, 21},
|
| 445 | { 0, 0, 6, 24}, { 0, 0, 6, 27},
|
| 446 | { 0, 0, 6, 30}, { 0, 0, 6, 33},
|
| 447 | { 0, 1, 6, 35}, { 0, 1, 6, 39},
|
| 448 | { 0, 2, 6, 43}, { 0, 3, 6, 51},
|
| 449 | { 0, 4, 6, 67}, { 0, 5, 6, 99},
|
| 450 | { 0, 8, 6, 259}, { 32, 0, 4, 4},
|
| 451 | { 48, 0, 4, 4}, { 16, 0, 4, 5},
|
| 452 | { 32, 0, 5, 7}, { 32, 0, 5, 8},
|
| 453 | { 32, 0, 5, 10}, { 32, 0, 5, 11},
|
| 454 | { 0, 0, 6, 14}, { 0, 0, 6, 17},
|
| 455 | { 0, 0, 6, 20}, { 0, 0, 6, 23},
|
| 456 | { 0, 0, 6, 26}, { 0, 0, 6, 29},
|
| 457 | { 0, 0, 6, 32}, { 0, 16, 6,65539},
|
| 458 | { 0, 15, 6,32771}, { 0, 14, 6,16387},
|
| 459 | { 0, 13, 6, 8195}, { 0, 12, 6, 4099},
|
| 460 | { 0, 11, 6, 2051}, { 0, 10, 6, 1027},
|
| 461 | };
|
| 462 |
|
| 463 |
|
| 464 | static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U8 nbAddBits)
|
| 465 | {
|
| 466 | void* ptr = dt;
|
| 467 | ZSTD_seqSymbol_header* const DTableH = (ZSTD_seqSymbol_header*)ptr;
|
| 468 | ZSTD_seqSymbol* const cell = dt + 1;
|
| 469 |
|
| 470 | DTableH->tableLog = 0;
|
| 471 | DTableH->fastMode = 0;
|
| 472 |
|
| 473 | cell->nbBits = 0;
|
| 474 | cell->nextState = 0;
|
| 475 | assert(nbAddBits < 255);
|
| 476 | cell->nbAdditionalBits = nbAddBits;
|
| 477 | cell->baseValue = baseValue;
|
| 478 | }
|
| 479 |
|
| 480 |
|
| 481 | |
| 482 | * generate FSE decoding table for one symbol (ll, ml or off)
|
| 483 | * cannot fail if input is valid =>
|
| 484 | * all inputs are presumed validated at this stage
|
| 485 | FORCE_INLINE_TEMPLATE
|
| 486 | void ZSTD_buildFSETable_body(ZSTD_seqSymbol* dt,
|
| 487 | const short* normalizedCounter, unsigned maxSymbolValue,
|
| 488 | const U32* baseValue, const U8* nbAdditionalBits,
|
| 489 | unsigned tableLog, void* wksp, size_t wkspSize)
|
| 490 | {
|
| 491 | ZSTD_seqSymbol* const tableDecode = dt+1;
|
| 492 | U32 const maxSV1 = maxSymbolValue + 1;
|
| 493 | U32 const tableSize = 1 << tableLog;
|
| 494 |
|
| 495 | U16* symbolNext = (U16*)wksp;
|
| 496 | BYTE* spread = (BYTE*)(symbolNext + MaxSeq + 1);
|
| 497 | U32 highThreshold = tableSize - 1;
|
| 498 |
|
| 499 |
|
| 500 |
|
| 501 | assert(maxSymbolValue <= MaxSeq);
|
| 502 | assert(tableLog <= MaxFSELog);
|
| 503 | assert(wkspSize >= ZSTD_BUILD_FSE_TABLE_WKSP_SIZE);
|
| 504 | (void)wkspSize;
|
| 505 |
|
| 506 | { ZSTD_seqSymbol_header DTableH;
|
| 507 | DTableH.tableLog = tableLog;
|
| 508 | DTableH.fastMode = 1;
|
| 509 | { S16 const largeLimit= (S16)(1 << (tableLog-1));
|
| 510 | U32 s;
|
| 511 | for (s=0; s<maxSV1; s++) {
|
| 512 | if (normalizedCounter[s]==-1) {
|
| 513 | tableDecode[highThreshold--].baseValue = s;
|
| 514 | symbolNext[s] = 1;
|
| 515 | } else {
|
| 516 | if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0;
|
| 517 | assert(normalizedCounter[s]>=0);
|
| 518 | symbolNext[s] = (U16)normalizedCounter[s];
|
| 519 | } } }
|
| 520 | ZSTD_memcpy(dt, &DTableH, sizeof(DTableH));
|
| 521 | }
|
| 522 |
|
| 523 |
|
| 524 | assert(tableSize <= 512);
|
| 525 | |
| 526 | * no low probability (-1 count) symbols. When compressing
|
| 527 | * small blocks we avoid low probability symbols to hit this
|
| 528 | * case, since header decoding speed matters more.
|
| 529 |
|
| 530 | if (highThreshold == tableSize - 1) {
|
| 531 | size_t const tableMask = tableSize-1;
|
| 532 | size_t const step = FSE_TABLESTEP(tableSize);
|
| 533 | |
| 534 | * We use a uint64_t to lay down 8 bytes at a time. This reduces branch
|
| 535 | * misses since small blocks generally have small table logs, so nearly
|
| 536 | * all symbols have counts <= 8. We ensure we have 8 bytes at the end of
|
| 537 | * our buffer to handle the over-write.
|
| 538 |
|
| 539 | {
|
| 540 | U64 const add = 0x0101010101010101ull;
|
| 541 | size_t pos = 0;
|
| 542 | U64 sv = 0;
|
| 543 | U32 s;
|
| 544 | for (s=0; s<maxSV1; ++s, sv += add) {
|
| 545 | int i;
|
| 546 | int const n = normalizedCounter[s];
|
| 547 | MEM_write64(spread + pos, sv);
|
| 548 | for (i = 8; i < n; i += 8) {
|
| 549 | MEM_write64(spread + pos + i, sv);
|
| 550 | }
|
| 551 | assert(n>=0);
|
| 552 | pos += (size_t)n;
|
| 553 | }
|
| 554 | }
|
| 555 | |
| 556 | * The benefit of doing it in two stages is that we avoid the
|
| 557 | * variable size inner loop, which caused lots of branch misses.
|
| 558 | * Now we can run through all the positions without any branch misses.
|
| 559 | * We unroll the loop twice, since that is what empirically worked best.
|
| 560 |
|
| 561 | {
|
| 562 | size_t position = 0;
|
| 563 | size_t s;
|
| 564 | size_t const unroll = 2;
|
| 565 | assert(tableSize % unroll == 0);
|
| 566 | for (s = 0; s < (size_t)tableSize; s += unroll) {
|
| 567 | size_t u;
|
| 568 | for (u = 0; u < unroll; ++u) {
|
| 569 | size_t const uPosition = (position + (u * step)) & tableMask;
|
| 570 | tableDecode[uPosition].baseValue = spread[s + u];
|
| 571 | }
|
| 572 | position = (position + (unroll * step)) & tableMask;
|
| 573 | }
|
| 574 | assert(position == 0);
|
| 575 | }
|
| 576 | } else {
|
| 577 | U32 const tableMask = tableSize-1;
|
| 578 | U32 const step = FSE_TABLESTEP(tableSize);
|
| 579 | U32 s, position = 0;
|
| 580 | for (s=0; s<maxSV1; s++) {
|
| 581 | int i;
|
| 582 | int const n = normalizedCounter[s];
|
| 583 | for (i=0; i<n; i++) {
|
| 584 | tableDecode[position].baseValue = s;
|
| 585 | position = (position + step) & tableMask;
|
| 586 | while (UNLIKELY(position > highThreshold)) position = (position + step) & tableMask;
|
| 587 | } }
|
| 588 | assert(position == 0);
|
| 589 | }
|
| 590 |
|
| 591 |
|
| 592 | {
|
| 593 | U32 u;
|
| 594 | for (u=0; u<tableSize; u++) {
|
| 595 | U32 const symbol = tableDecode[u].baseValue;
|
| 596 | U32 const nextState = symbolNext[symbol]++;
|
| 597 | tableDecode[u].nbBits = (BYTE) (tableLog - ZSTD_highbit32(nextState) );
|
| 598 | tableDecode[u].nextState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize);
|
| 599 | assert(nbAdditionalBits[symbol] < 255);
|
| 600 | tableDecode[u].nbAdditionalBits = nbAdditionalBits[symbol];
|
| 601 | tableDecode[u].baseValue = baseValue[symbol];
|
| 602 | }
|
| 603 | }
|
| 604 | }
|
| 605 |
|
| 606 |
|
| 607 | static void ZSTD_buildFSETable_body_default(ZSTD_seqSymbol* dt,
|
| 608 | const short* normalizedCounter, unsigned maxSymbolValue,
|
| 609 | const U32* baseValue, const U8* nbAdditionalBits,
|
| 610 | unsigned tableLog, void* wksp, size_t wkspSize)
|
| 611 | {
|
| 612 | ZSTD_buildFSETable_body(dt, normalizedCounter, maxSymbolValue,
|
| 613 | baseValue, nbAdditionalBits, tableLog, wksp, wkspSize);
|
| 614 | }
|
| 615 |
|
| 616 | #if DYNAMIC_BMI2
|
| 617 | BMI2_TARGET_ATTRIBUTE static void ZSTD_buildFSETable_body_bmi2(ZSTD_seqSymbol* dt,
|
| 618 | const short* normalizedCounter, unsigned maxSymbolValue,
|
| 619 | const U32* baseValue, const U8* nbAdditionalBits,
|
| 620 | unsigned tableLog, void* wksp, size_t wkspSize)
|
| 621 | {
|
| 622 | ZSTD_buildFSETable_body(dt, normalizedCounter, maxSymbolValue,
|
| 623 | baseValue, nbAdditionalBits, tableLog, wksp, wkspSize);
|
| 624 | }
|
| 625 | #endif
|
| 626 |
|
| 627 | void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
|
| 628 | const short* normalizedCounter, unsigned maxSymbolValue,
|
| 629 | const U32* baseValue, const U8* nbAdditionalBits,
|
| 630 | unsigned tableLog, void* wksp, size_t wkspSize, int bmi2)
|
| 631 | {
|
| 632 | #if DYNAMIC_BMI2
|
| 633 | if (bmi2) {
|
| 634 | ZSTD_buildFSETable_body_bmi2(dt, normalizedCounter, maxSymbolValue,
|
| 635 | baseValue, nbAdditionalBits, tableLog, wksp, wkspSize);
|
| 636 | return;
|
| 637 | }
|
| 638 | #endif
|
| 639 | (void)bmi2;
|
| 640 | ZSTD_buildFSETable_body_default(dt, normalizedCounter, maxSymbolValue,
|
| 641 | baseValue, nbAdditionalBits, tableLog, wksp, wkspSize);
|
| 642 | }
|
| 643 |
|
| 644 |
|
| 645 | |
| 646 | * @return : nb bytes read from src,
|
| 647 | * or an error code if it fails
|
| 648 | static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymbol** DTablePtr,
|
| 649 | SymbolEncodingType_e type, unsigned max, U32 maxLog,
|
| 650 | const void* src, size_t srcSize,
|
| 651 | const U32* baseValue, const U8* nbAdditionalBits,
|
| 652 | const ZSTD_seqSymbol* defaultTable, U32 flagRepeatTable,
|
| 653 | int ddictIsCold, int nbSeq, U32* wksp, size_t wkspSize,
|
| 654 | int bmi2)
|
| 655 | {
|
| 656 | switch(type)
|
| 657 | {
|
| 658 | case set_rle :
|
| 659 | RETURN_ERROR_IF(!srcSize, srcSize_wrong, "");
|
| 660 | RETURN_ERROR_IF((*(const BYTE*)src) > max, corruption_detected, "");
|
| 661 | { U32 const symbol = *(const BYTE*)src;
|
| 662 | U32 const baseline = baseValue[symbol];
|
| 663 | U8 const nbBits = nbAdditionalBits[symbol];
|
| 664 | ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits);
|
| 665 | }
|
| 666 | *DTablePtr = DTableSpace;
|
| 667 | return 1;
|
| 668 | case set_basic :
|
| 669 | *DTablePtr = defaultTable;
|
| 670 | return 0;
|
| 671 | case set_repeat:
|
| 672 | RETURN_ERROR_IF(!flagRepeatTable, corruption_detected, "");
|
| 673 |
|
| 674 | if (ddictIsCold && (nbSeq > 24 )) {
|
| 675 | const void* const pStart = *DTablePtr;
|
| 676 | size_t const pSize = sizeof(ZSTD_seqSymbol) * (SEQSYMBOL_TABLE_SIZE(maxLog));
|
| 677 | PREFETCH_AREA(pStart, pSize);
|
| 678 | }
|
| 679 | return 0;
|
| 680 | case set_compressed :
|
| 681 | { unsigned tableLog;
|
| 682 | S16 norm[MaxSeq+1];
|
| 683 | size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
|
| 684 | RETURN_ERROR_IF(FSE_isError(headerSize), corruption_detected, "");
|
| 685 | RETURN_ERROR_IF(tableLog > maxLog, corruption_detected, "");
|
| 686 | ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog, wksp, wkspSize, bmi2);
|
| 687 | *DTablePtr = DTableSpace;
|
| 688 | return headerSize;
|
| 689 | }
|
| 690 | default :
|
| 691 | assert(0);
|
| 692 | RETURN_ERROR(GENERIC, "impossible");
|
| 693 | }
|
| 694 | }
|
| 695 |
|
| 696 | size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
|
| 697 | const void* src, size_t srcSize)
|
| 698 | {
|
| 699 | const BYTE* const istart = (const BYTE*)src;
|
| 700 | const BYTE* const iend = istart + srcSize;
|
| 701 | const BYTE* ip = istart;
|
| 702 | int nbSeq;
|
| 703 | DEBUGLOG(5, "ZSTD_decodeSeqHeaders");
|
| 704 |
|
| 705 |
|
| 706 | RETURN_ERROR_IF(srcSize < MIN_SEQUENCES_SIZE, srcSize_wrong, "");
|
| 707 |
|
| 708 |
|
| 709 | nbSeq = *ip++;
|
| 710 | if (nbSeq > 0x7F) {
|
| 711 | if (nbSeq == 0xFF) {
|
| 712 | RETURN_ERROR_IF(ip+2 > iend, srcSize_wrong, "");
|
| 713 | nbSeq = MEM_readLE16(ip) + LONGNBSEQ;
|
| 714 | ip+=2;
|
| 715 | } else {
|
| 716 | RETURN_ERROR_IF(ip >= iend, srcSize_wrong, "");
|
| 717 | nbSeq = ((nbSeq-0x80)<<8) + *ip++;
|
| 718 | }
|
| 719 | }
|
| 720 | *nbSeqPtr = nbSeq;
|
| 721 |
|
| 722 | if (nbSeq == 0) {
|
| 723 |
|
| 724 | RETURN_ERROR_IF(ip != iend, corruption_detected,
|
| 725 | "extraneous data present in the Sequences section");
|
| 726 | return (size_t)(ip - istart);
|
| 727 | }
|
| 728 |
|
| 729 |
|
| 730 | RETURN_ERROR_IF(ip+1 > iend, srcSize_wrong, "");
|
| 731 | RETURN_ERROR_IF(*ip & 3, corruption_detected, "");
|
| 732 | { SymbolEncodingType_e const LLtype = (SymbolEncodingType_e)(*ip >> 6);
|
| 733 | SymbolEncodingType_e const OFtype = (SymbolEncodingType_e)((*ip >> 4) & 3);
|
| 734 | SymbolEncodingType_e const MLtype = (SymbolEncodingType_e)((*ip >> 2) & 3);
|
| 735 | ip++;
|
| 736 |
|
| 737 |
|
| 738 | { size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr,
|
| 739 | LLtype, MaxLL, LLFSELog,
|
| 740 | ip, iend-ip,
|
| 741 | LL_base, LL_bits,
|
| 742 | LL_defaultDTable, dctx->fseEntropy,
|
| 743 | dctx->ddictIsCold, nbSeq,
|
| 744 | dctx->workspace, sizeof(dctx->workspace),
|
| 745 | ZSTD_DCtx_get_bmi2(dctx));
|
| 746 | RETURN_ERROR_IF(ZSTD_isError(llhSize), corruption_detected, "ZSTD_buildSeqTable failed");
|
| 747 | ip += llhSize;
|
| 748 | }
|
| 749 |
|
| 750 | { size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr,
|
| 751 | OFtype, MaxOff, OffFSELog,
|
| 752 | ip, iend-ip,
|
| 753 | OF_base, OF_bits,
|
| 754 | OF_defaultDTable, dctx->fseEntropy,
|
| 755 | dctx->ddictIsCold, nbSeq,
|
| 756 | dctx->workspace, sizeof(dctx->workspace),
|
| 757 | ZSTD_DCtx_get_bmi2(dctx));
|
| 758 | RETURN_ERROR_IF(ZSTD_isError(ofhSize), corruption_detected, "ZSTD_buildSeqTable failed");
|
| 759 | ip += ofhSize;
|
| 760 | }
|
| 761 |
|
| 762 | { size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr,
|
| 763 | MLtype, MaxML, MLFSELog,
|
| 764 | ip, iend-ip,
|
| 765 | ML_base, ML_bits,
|
| 766 | ML_defaultDTable, dctx->fseEntropy,
|
| 767 | dctx->ddictIsCold, nbSeq,
|
| 768 | dctx->workspace, sizeof(dctx->workspace),
|
| 769 | ZSTD_DCtx_get_bmi2(dctx));
|
| 770 | RETURN_ERROR_IF(ZSTD_isError(mlhSize), corruption_detected, "ZSTD_buildSeqTable failed");
|
| 771 | ip += mlhSize;
|
| 772 | }
|
| 773 | }
|
| 774 |
|
| 775 | return ip-istart;
|
| 776 | }
|
| 777 |
|
| 778 |
|
| 779 | typedef struct {
|
| 780 | size_t litLength;
|
| 781 | size_t matchLength;
|
| 782 | size_t offset;
|
| 783 | } seq_t;
|
| 784 |
|
| 785 | typedef struct {
|
| 786 | size_t state;
|
| 787 | const ZSTD_seqSymbol* table;
|
| 788 | } ZSTD_fseState;
|
| 789 |
|
| 790 | typedef struct {
|
| 791 | BIT_DStream_t DStream;
|
| 792 | ZSTD_fseState stateLL;
|
| 793 | ZSTD_fseState stateOffb;
|
| 794 | ZSTD_fseState stateML;
|
| 795 | size_t prevOffset[ZSTD_REP_NUM];
|
| 796 | } seqState_t;
|
| 797 |
|
| 798 | |
| 799 | * Copies 8 bytes from ip to op and updates op and ip where ip <= op.
|
| 800 | * If the offset is < 8 then the offset is spread to at least 8 bytes.
|
| 801 | *
|
| 802 | * Precondition: *ip <= *op
|
| 803 | * Postcondition: *op - *op >= 8
|
| 804 |
|
| 805 | HINT_INLINE void ZSTD_overlapCopy8(BYTE** op, BYTE const** ip, size_t offset) {
|
| 806 | assert(*ip <= *op);
|
| 807 | if (offset < 8) {
|
| 808 |
|
| 809 | static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };
|
| 810 | static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };
|
| 811 | int const sub2 = dec64table[offset];
|
| 812 | (*op)[0] = (*ip)[0];
|
| 813 | (*op)[1] = (*ip)[1];
|
| 814 | (*op)[2] = (*ip)[2];
|
| 815 | (*op)[3] = (*ip)[3];
|
| 816 | *ip += dec32table[offset];
|
| 817 | ZSTD_copy4(*op+4, *ip);
|
| 818 | *ip -= sub2;
|
| 819 | } else {
|
| 820 | ZSTD_copy8(*op, *ip);
|
| 821 | }
|
| 822 | *ip += 8;
|
| 823 | *op += 8;
|
| 824 | assert(*op - *ip >= 8);
|
| 825 | }
|
| 826 |
|
| 827 | |
| 828 | * Specialized version of memcpy() that is allowed to READ up to WILDCOPY_OVERLENGTH past the input buffer
|
| 829 | * and write up to 16 bytes past oend_w (op >= oend_w is allowed).
|
| 830 | * This function is only called in the uncommon case where the sequence is near the end of the block. It
|
| 831 | * should be fast for a single long sequence, but can be slow for several short sequences.
|
| 832 | *
|
| 833 | * @param ovtype controls the overlap detection
|
| 834 | * - ZSTD_no_overlap: The source and destination are guaranteed to be at least WILDCOPY_VECLEN bytes apart.
|
| 835 | * - ZSTD_overlap_src_before_dst: The src and dst may overlap and may be any distance apart.
|
| 836 | * The src buffer must be before the dst buffer.
|
| 837 |
|
| 838 | static void ZSTD_safecopy(BYTE* op, const BYTE* const oend_w, BYTE const* ip, ptrdiff_t length, ZSTD_overlap_e ovtype) {
|
| 839 | ptrdiff_t const diff = op - ip;
|
| 840 | BYTE* const oend = op + length;
|
| 841 |
|
| 842 | assert((ovtype == ZSTD_no_overlap && (diff <= -8 || diff >= 8 || op >= oend_w)) ||
|
| 843 | (ovtype == ZSTD_overlap_src_before_dst && diff >= 0));
|
| 844 |
|
| 845 | if (length < 8) {
|
| 846 |
|
| 847 | while (op < oend) *op++ = *ip++;
|
| 848 | return;
|
| 849 | }
|
| 850 | if (ovtype == ZSTD_overlap_src_before_dst) {
|
| 851 |
|
| 852 | assert(length >= 8);
|
| 853 | ZSTD_overlapCopy8(&op, &ip, diff);
|
| 854 | length -= 8;
|
| 855 | assert(op - ip >= 8);
|
| 856 | assert(op <= oend);
|
| 857 | }
|
| 858 |
|
| 859 | if (oend <= oend_w) {
|
| 860 |
|
| 861 | ZSTD_wildcopy(op, ip, length, ovtype);
|
| 862 | return;
|
| 863 | }
|
| 864 | if (op <= oend_w) {
|
| 865 |
|
| 866 | assert(oend > oend_w);
|
| 867 | ZSTD_wildcopy(op, ip, oend_w - op, ovtype);
|
| 868 | ip += oend_w - op;
|
| 869 | op += oend_w - op;
|
| 870 | }
|
| 871 |
|
| 872 | while (op < oend) *op++ = *ip++;
|
| 873 | }
|
| 874 |
|
| 875 | |
| 876 | * This version allows overlap with dst before src, or handles the non-overlap case with dst after src
|
| 877 | * Kept separate from more common ZSTD_safecopy case to avoid performance impact to the safecopy common case
|
| 878 | static void ZSTD_safecopyDstBeforeSrc(BYTE* op, const BYTE* ip, ptrdiff_t length) {
|
| 879 | ptrdiff_t const diff = op - ip;
|
| 880 | BYTE* const oend = op + length;
|
| 881 |
|
| 882 | if (length < 8 || diff > -8) {
|
| 883 |
|
| 884 | while (op < oend) *op++ = *ip++;
|
| 885 | return;
|
| 886 | }
|
| 887 |
|
| 888 | if (op <= oend - WILDCOPY_OVERLENGTH && diff < -WILDCOPY_VECLEN) {
|
| 889 | ZSTD_wildcopy(op, ip, oend - WILDCOPY_OVERLENGTH - op, ZSTD_no_overlap);
|
| 890 | ip += oend - WILDCOPY_OVERLENGTH - op;
|
| 891 | op += oend - WILDCOPY_OVERLENGTH - op;
|
| 892 | }
|
| 893 |
|
| 894 |
|
| 895 | while (op < oend) *op++ = *ip++;
|
| 896 | }
|
| 897 |
|
| 898 | |
| 899 | * This version handles cases that are near the end of the output buffer. It requires
|
| 900 | * more careful checks to make sure there is no overflow. By separating out these hard
|
| 901 | * and unlikely cases, we can speed up the common cases.
|
| 902 | *
|
| 903 | * NOTE: This function needs to be fast for a single long sequence, but doesn't need
|
| 904 | * to be optimized for many small sequences, since those fall into ZSTD_execSequence().
|
| 905 |
|
| 906 | FORCE_NOINLINE
|
| 907 | ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
|
| 908 | size_t ZSTD_execSequenceEnd(BYTE* op,
|
| 909 | BYTE* const oend, seq_t sequence,
|
| 910 | const BYTE** litPtr, const BYTE* const litLimit,
|
| 911 | const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
|
| 912 | {
|
| 913 | BYTE* const oLitEnd = op + sequence.litLength;
|
| 914 | size_t const sequenceLength = sequence.litLength + sequence.matchLength;
|
| 915 | const BYTE* const iLitEnd = *litPtr + sequence.litLength;
|
| 916 | const BYTE* match = oLitEnd - sequence.offset;
|
| 917 | BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
|
| 918 |
|
| 919 |
|
| 920 | RETURN_ERROR_IF(sequenceLength > (size_t)(oend - op), dstSize_tooSmall, "last match must fit within dstBuffer");
|
| 921 | RETURN_ERROR_IF(sequence.litLength > (size_t)(litLimit - *litPtr), corruption_detected, "try to read beyond literal buffer");
|
| 922 | assert(op < op + sequenceLength);
|
| 923 | assert(oLitEnd < op + sequenceLength);
|
| 924 |
|
| 925 |
|
| 926 | ZSTD_safecopy(op, oend_w, *litPtr, sequence.litLength, ZSTD_no_overlap);
|
| 927 | op = oLitEnd;
|
| 928 | *litPtr = iLitEnd;
|
| 929 |
|
| 930 |
|
| 931 | if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
|
| 932 |
|
| 933 | RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected, "");
|
| 934 | match = dictEnd - (prefixStart - match);
|
| 935 | if (match + sequence.matchLength <= dictEnd) {
|
| 936 | ZSTD_memmove(oLitEnd, match, sequence.matchLength);
|
| 937 | return sequenceLength;
|
| 938 | }
|
| 939 |
|
| 940 | { size_t const length1 = dictEnd - match;
|
| 941 | ZSTD_memmove(oLitEnd, match, length1);
|
| 942 | op = oLitEnd + length1;
|
| 943 | sequence.matchLength -= length1;
|
| 944 | match = prefixStart;
|
| 945 | }
|
| 946 | }
|
| 947 | ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst);
|
| 948 | return sequenceLength;
|
| 949 | }
|
| 950 |
|
| 951 | |
| 952 | * This version is intended to be used during instances where the litBuffer is still split. It is kept separate to avoid performance impact for the good case.
|
| 953 |
|
| 954 | FORCE_NOINLINE
|
| 955 | ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
|
| 956 | size_t ZSTD_execSequenceEndSplitLitBuffer(BYTE* op,
|
| 957 | BYTE* const oend, const BYTE* const oend_w, seq_t sequence,
|
| 958 | const BYTE** litPtr, const BYTE* const litLimit,
|
| 959 | const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
|
| 960 | {
|
| 961 | BYTE* const oLitEnd = op + sequence.litLength;
|
| 962 | size_t const sequenceLength = sequence.litLength + sequence.matchLength;
|
| 963 | const BYTE* const iLitEnd = *litPtr + sequence.litLength;
|
| 964 | const BYTE* match = oLitEnd - sequence.offset;
|
| 965 |
|
| 966 |
|
| 967 |
|
| 968 | RETURN_ERROR_IF(sequenceLength > (size_t)(oend - op), dstSize_tooSmall, "last match must fit within dstBuffer");
|
| 969 | RETURN_ERROR_IF(sequence.litLength > (size_t)(litLimit - *litPtr), corruption_detected, "try to read beyond literal buffer");
|
| 970 | assert(op < op + sequenceLength);
|
| 971 | assert(oLitEnd < op + sequenceLength);
|
| 972 |
|
| 973 |
|
| 974 | RETURN_ERROR_IF(op > *litPtr && op < *litPtr + sequence.litLength, dstSize_tooSmall, "output should not catch up to and overwrite literal buffer");
|
| 975 | ZSTD_safecopyDstBeforeSrc(op, *litPtr, sequence.litLength);
|
| 976 | op = oLitEnd;
|
| 977 | *litPtr = iLitEnd;
|
| 978 |
|
| 979 |
|
| 980 | if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
|
| 981 |
|
| 982 | RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected, "");
|
| 983 | match = dictEnd - (prefixStart - match);
|
| 984 | if (match + sequence.matchLength <= dictEnd) {
|
| 985 | ZSTD_memmove(oLitEnd, match, sequence.matchLength);
|
| 986 | return sequenceLength;
|
| 987 | }
|
| 988 |
|
| 989 | { size_t const length1 = dictEnd - match;
|
| 990 | ZSTD_memmove(oLitEnd, match, length1);
|
| 991 | op = oLitEnd + length1;
|
| 992 | sequence.matchLength -= length1;
|
| 993 | match = prefixStart;
|
| 994 | }
|
| 995 | }
|
| 996 | ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst);
|
| 997 | return sequenceLength;
|
| 998 | }
|
| 999 |
|
| 1000 | HINT_INLINE
|
| 1001 | ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
|
| 1002 | size_t ZSTD_execSequence(BYTE* op,
|
| 1003 | BYTE* const oend, seq_t sequence,
|
| 1004 | const BYTE** litPtr, const BYTE* const litLimit,
|
| 1005 | const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
|
| 1006 | {
|
| 1007 | BYTE* const oLitEnd = op + sequence.litLength;
|
| 1008 | size_t const sequenceLength = sequence.litLength + sequence.matchLength;
|
| 1009 | BYTE* const oMatchEnd = op + sequenceLength;
|
| 1010 | BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
|
| 1011 | const BYTE* const iLitEnd = *litPtr + sequence.litLength;
|
| 1012 | const BYTE* match = oLitEnd - sequence.offset;
|
| 1013 |
|
| 1014 | assert(op != NULL );
|
| 1015 | assert(oend_w < oend );
|
| 1016 |
|
| 1017 | #if defined(__aarch64__)
|
| 1018 |
|
| 1019 | PREFETCH_L1(match);
|
| 1020 | #endif
|
| 1021 | |
| 1022 | * - Read beyond end of literals
|
| 1023 | * - Match end is within WILDCOPY_OVERLIMIT of oend
|
| 1024 | * - 32-bit mode and the match length overflows
|
| 1025 |
|
| 1026 | if (UNLIKELY(
|
| 1027 | iLitEnd > litLimit ||
|
| 1028 | oMatchEnd > oend_w ||
|
| 1029 | (MEM_32bits() && (size_t)(oend - op) < sequenceLength + WILDCOPY_OVERLENGTH)))
|
| 1030 | return ZSTD_execSequenceEnd(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd);
|
| 1031 |
|
| 1032 |
|
| 1033 | assert(op <= oLitEnd );
|
| 1034 | assert(oLitEnd < oMatchEnd );
|
| 1035 | assert(oMatchEnd <= oend );
|
| 1036 | assert(iLitEnd <= litLimit );
|
| 1037 | assert(oLitEnd <= oend_w );
|
| 1038 | assert(oMatchEnd <= oend_w );
|
| 1039 |
|
| 1040 | |
| 1041 | * Split out litLength <= 16 since it is nearly always true. +1.6% on gcc-9.
|
| 1042 | * We likely don't need the full 32-byte wildcopy.
|
| 1043 |
|
| 1044 | assert(WILDCOPY_OVERLENGTH >= 16);
|
| 1045 | ZSTD_copy16(op, (*litPtr));
|
| 1046 | if (UNLIKELY(sequence.litLength > 16)) {
|
| 1047 | ZSTD_wildcopy(op + 16, (*litPtr) + 16, sequence.litLength - 16, ZSTD_no_overlap);
|
| 1048 | }
|
| 1049 | op = oLitEnd;
|
| 1050 | *litPtr = iLitEnd;
|
| 1051 |
|
| 1052 |
|
| 1053 | if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
|
| 1054 |
|
| 1055 | RETURN_ERROR_IF(UNLIKELY(sequence.offset > (size_t)(oLitEnd - virtualStart)), corruption_detected, "");
|
| 1056 | match = dictEnd + (match - prefixStart);
|
| 1057 | if (match + sequence.matchLength <= dictEnd) {
|
| 1058 | ZSTD_memmove(oLitEnd, match, sequence.matchLength);
|
| 1059 | return sequenceLength;
|
| 1060 | }
|
| 1061 |
|
| 1062 | { size_t const length1 = dictEnd - match;
|
| 1063 | ZSTD_memmove(oLitEnd, match, length1);
|
| 1064 | op = oLitEnd + length1;
|
| 1065 | sequence.matchLength -= length1;
|
| 1066 | match = prefixStart;
|
| 1067 | }
|
| 1068 | }
|
| 1069 |
|
| 1070 | assert(op <= oMatchEnd);
|
| 1071 | assert(oMatchEnd <= oend_w);
|
| 1072 | assert(match >= prefixStart);
|
| 1073 | assert(sequence.matchLength >= 1);
|
| 1074 |
|
| 1075 | |
| 1076 | * without overlap checking.
|
| 1077 |
|
| 1078 | if (LIKELY(sequence.offset >= WILDCOPY_VECLEN)) {
|
| 1079 | |
| 1080 | * longer than literals (in general). In silesia, ~10% of matches are longer
|
| 1081 | * than 16 bytes.
|
| 1082 |
|
| 1083 | ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap);
|
| 1084 | return sequenceLength;
|
| 1085 | }
|
| 1086 | assert(sequence.offset < WILDCOPY_VECLEN);
|
| 1087 |
|
| 1088 |
|
| 1089 | ZSTD_overlapCopy8(&op, &match, sequence.offset);
|
| 1090 |
|
| 1091 |
|
| 1092 | if (sequence.matchLength > 8) {
|
| 1093 | assert(op < oMatchEnd);
|
| 1094 | ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength - 8, ZSTD_overlap_src_before_dst);
|
| 1095 | }
|
| 1096 | return sequenceLength;
|
| 1097 | }
|
| 1098 |
|
| 1099 | HINT_INLINE
|
| 1100 | ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
|
| 1101 | size_t ZSTD_execSequenceSplitLitBuffer(BYTE* op,
|
| 1102 | BYTE* const oend, const BYTE* const oend_w, seq_t sequence,
|
| 1103 | const BYTE** litPtr, const BYTE* const litLimit,
|
| 1104 | const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
|
| 1105 | {
|
| 1106 | BYTE* const oLitEnd = op + sequence.litLength;
|
| 1107 | size_t const sequenceLength = sequence.litLength + sequence.matchLength;
|
| 1108 | BYTE* const oMatchEnd = op + sequenceLength;
|
| 1109 | const BYTE* const iLitEnd = *litPtr + sequence.litLength;
|
| 1110 | const BYTE* match = oLitEnd - sequence.offset;
|
| 1111 |
|
| 1112 | assert(op != NULL );
|
| 1113 | assert(oend_w < oend );
|
| 1114 | |
| 1115 | * - Read beyond end of literals
|
| 1116 | * - Match end is within WILDCOPY_OVERLIMIT of oend
|
| 1117 | * - 32-bit mode and the match length overflows
|
| 1118 |
|
| 1119 | if (UNLIKELY(
|
| 1120 | iLitEnd > litLimit ||
|
| 1121 | oMatchEnd > oend_w ||
|
| 1122 | (MEM_32bits() && (size_t)(oend - op) < sequenceLength + WILDCOPY_OVERLENGTH)))
|
| 1123 | return ZSTD_execSequenceEndSplitLitBuffer(op, oend, oend_w, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd);
|
| 1124 |
|
| 1125 |
|
| 1126 | assert(op <= oLitEnd );
|
| 1127 | assert(oLitEnd < oMatchEnd );
|
| 1128 | assert(oMatchEnd <= oend );
|
| 1129 | assert(iLitEnd <= litLimit );
|
| 1130 | assert(oLitEnd <= oend_w );
|
| 1131 | assert(oMatchEnd <= oend_w );
|
| 1132 |
|
| 1133 | |
| 1134 | * Split out litLength <= 16 since it is nearly always true. +1.6% on gcc-9.
|
| 1135 | * We likely don't need the full 32-byte wildcopy.
|
| 1136 |
|
| 1137 | assert(WILDCOPY_OVERLENGTH >= 16);
|
| 1138 | ZSTD_copy16(op, (*litPtr));
|
| 1139 | if (UNLIKELY(sequence.litLength > 16)) {
|
| 1140 | ZSTD_wildcopy(op+16, (*litPtr)+16, sequence.litLength-16, ZSTD_no_overlap);
|
| 1141 | }
|
| 1142 | op = oLitEnd;
|
| 1143 | *litPtr = iLitEnd;
|
| 1144 |
|
| 1145 |
|
| 1146 | if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
|
| 1147 |
|
| 1148 | RETURN_ERROR_IF(UNLIKELY(sequence.offset > (size_t)(oLitEnd - virtualStart)), corruption_detected, "");
|
| 1149 | match = dictEnd + (match - prefixStart);
|
| 1150 | if (match + sequence.matchLength <= dictEnd) {
|
| 1151 | ZSTD_memmove(oLitEnd, match, sequence.matchLength);
|
| 1152 | return sequenceLength;
|
| 1153 | }
|
| 1154 |
|
| 1155 | { size_t const length1 = dictEnd - match;
|
| 1156 | ZSTD_memmove(oLitEnd, match, length1);
|
| 1157 | op = oLitEnd + length1;
|
| 1158 | sequence.matchLength -= length1;
|
| 1159 | match = prefixStart;
|
| 1160 | } }
|
| 1161 |
|
| 1162 | assert(op <= oMatchEnd);
|
| 1163 | assert(oMatchEnd <= oend_w);
|
| 1164 | assert(match >= prefixStart);
|
| 1165 | assert(sequence.matchLength >= 1);
|
| 1166 |
|
| 1167 | |
| 1168 | * without overlap checking.
|
| 1169 |
|
| 1170 | if (LIKELY(sequence.offset >= WILDCOPY_VECLEN)) {
|
| 1171 | |
| 1172 | * longer than literals (in general). In silesia, ~10% of matches are longer
|
| 1173 | * than 16 bytes.
|
| 1174 |
|
| 1175 | ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap);
|
| 1176 | return sequenceLength;
|
| 1177 | }
|
| 1178 | assert(sequence.offset < WILDCOPY_VECLEN);
|
| 1179 |
|
| 1180 |
|
| 1181 | ZSTD_overlapCopy8(&op, &match, sequence.offset);
|
| 1182 |
|
| 1183 |
|
| 1184 | if (sequence.matchLength > 8) {
|
| 1185 | assert(op < oMatchEnd);
|
| 1186 | ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8, ZSTD_overlap_src_before_dst);
|
| 1187 | }
|
| 1188 | return sequenceLength;
|
| 1189 | }
|
| 1190 |
|
| 1191 |
|
| 1192 | static void
|
| 1193 | ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt)
|
| 1194 | {
|
| 1195 | const void* ptr = dt;
|
| 1196 | const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr;
|
| 1197 | DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
|
| 1198 | DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits",
|
| 1199 | (U32)DStatePtr->state, DTableH->tableLog);
|
| 1200 | BIT_reloadDStream(bitD);
|
| 1201 | DStatePtr->table = dt + 1;
|
| 1202 | }
|
| 1203 |
|
| 1204 | FORCE_INLINE_TEMPLATE void
|
| 1205 | ZSTD_updateFseStateWithDInfo(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, U16 nextState, U32 nbBits)
|
| 1206 | {
|
| 1207 | size_t const lowBits = BIT_readBits(bitD, nbBits);
|
| 1208 | DStatePtr->state = nextState + lowBits;
|
| 1209 | }
|
| 1210 |
|
| 1211 | |
| 1212 | * offset bits. But we can only read at most STREAM_ACCUMULATOR_MIN_32
|
| 1213 | * bits before reloading. This value is the maximum number of bytes we read
|
| 1214 | * after reloading when we are decoding long offsets.
|
| 1215 |
|
| 1216 | #define LONG_OFFSETS_MAX_EXTRA_BITS_32 \
|
| 1217 | (ZSTD_WINDOWLOG_MAX_32 > STREAM_ACCUMULATOR_MIN_32 \
|
| 1218 | ? ZSTD_WINDOWLOG_MAX_32 - STREAM_ACCUMULATOR_MIN_32 \
|
| 1219 | : 0)
|
| 1220 |
|
| 1221 | typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e;
|
| 1222 |
|
| 1223 | |
| 1224 | * ZSTD_decodeSequence():
|
| 1225 | * @p longOffsets : tells the decoder to reload more bit while decoding large offsets
|
| 1226 | * only used in 32-bit mode
|
| 1227 | * @return : Sequence (litL + matchL + offset)
|
| 1228 |
|
| 1229 | FORCE_INLINE_TEMPLATE seq_t
|
| 1230 | ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets, const int isLastSeq)
|
| 1231 | {
|
| 1232 | seq_t seq;
|
| 1233 | |
| 1234 | * ZSTD_seqSymbol is a 64 bits wide structure.
|
| 1235 | * It can be loaded in one operation
|
| 1236 | * and its fields extracted by simply shifting or bit-extracting on aarch64.
|
| 1237 | * GCC doesn't recognize this and generates more unnecessary ldr/ldrb/ldrh
|
| 1238 | * operations that cause performance drop. This can be avoided by using this
|
| 1239 | * ZSTD_memcpy hack.
|
| 1240 |
|
| 1241 | #if defined(__aarch64__) && (defined(__GNUC__) && !defined(__clang__))
|
| 1242 | ZSTD_seqSymbol llDInfoS, mlDInfoS, ofDInfoS;
|
| 1243 | ZSTD_seqSymbol* const llDInfo = &llDInfoS;
|
| 1244 | ZSTD_seqSymbol* const mlDInfo = &mlDInfoS;
|
| 1245 | ZSTD_seqSymbol* const ofDInfo = &ofDInfoS;
|
| 1246 | ZSTD_memcpy(llDInfo, seqState->stateLL.table + seqState->stateLL.state, sizeof(ZSTD_seqSymbol));
|
| 1247 | ZSTD_memcpy(mlDInfo, seqState->stateML.table + seqState->stateML.state, sizeof(ZSTD_seqSymbol));
|
| 1248 | ZSTD_memcpy(ofDInfo, seqState->stateOffb.table + seqState->stateOffb.state, sizeof(ZSTD_seqSymbol));
|
| 1249 | #else
|
| 1250 | const ZSTD_seqSymbol* const llDInfo = seqState->stateLL.table + seqState->stateLL.state;
|
| 1251 | const ZSTD_seqSymbol* const mlDInfo = seqState->stateML.table + seqState->stateML.state;
|
| 1252 | const ZSTD_seqSymbol* const ofDInfo = seqState->stateOffb.table + seqState->stateOffb.state;
|
| 1253 | #endif
|
| 1254 | seq.matchLength = mlDInfo->baseValue;
|
| 1255 | seq.litLength = llDInfo->baseValue;
|
| 1256 | { U32 const ofBase = ofDInfo->baseValue;
|
| 1257 | BYTE const llBits = llDInfo->nbAdditionalBits;
|
| 1258 | BYTE const mlBits = mlDInfo->nbAdditionalBits;
|
| 1259 | BYTE const ofBits = ofDInfo->nbAdditionalBits;
|
| 1260 | BYTE const totalBits = llBits+mlBits+ofBits;
|
| 1261 |
|
| 1262 | U16 const llNext = llDInfo->nextState;
|
| 1263 | U16 const mlNext = mlDInfo->nextState;
|
| 1264 | U16 const ofNext = ofDInfo->nextState;
|
| 1265 | U32 const llnbBits = llDInfo->nbBits;
|
| 1266 | U32 const mlnbBits = mlDInfo->nbBits;
|
| 1267 | U32 const ofnbBits = ofDInfo->nbBits;
|
| 1268 |
|
| 1269 | assert(llBits <= MaxLLBits);
|
| 1270 | assert(mlBits <= MaxMLBits);
|
| 1271 | assert(ofBits <= MaxOff);
|
| 1272 | |
| 1273 | * As gcc has better branch and block analyzers, sometimes it is only
|
| 1274 | * valuable to mark likeliness for clang, it gives around 3-4% of
|
| 1275 | * performance.
|
| 1276 |
|
| 1277 |
|
| 1278 |
|
| 1279 | { size_t offset;
|
| 1280 | if (ofBits > 1) {
|
| 1281 | ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
|
| 1282 | ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
|
| 1283 | ZSTD_STATIC_ASSERT(STREAM_ACCUMULATOR_MIN_32 > LONG_OFFSETS_MAX_EXTRA_BITS_32);
|
| 1284 | ZSTD_STATIC_ASSERT(STREAM_ACCUMULATOR_MIN_32 - LONG_OFFSETS_MAX_EXTRA_BITS_32 >= MaxMLBits);
|
| 1285 | if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) {
|
| 1286 | |
| 1287 | * avoids branches, and avoids accidentally reading 0 bits.
|
| 1288 |
|
| 1289 | U32 const extraBits = LONG_OFFSETS_MAX_EXTRA_BITS_32;
|
| 1290 | offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
|
| 1291 | BIT_reloadDStream(&seqState->DStream);
|
| 1292 | offset += BIT_readBitsFast(&seqState->DStream, extraBits);
|
| 1293 | } else {
|
| 1294 | offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits);
|
| 1295 | if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
|
| 1296 | }
|
| 1297 | seqState->prevOffset[2] = seqState->prevOffset[1];
|
| 1298 | seqState->prevOffset[1] = seqState->prevOffset[0];
|
| 1299 | seqState->prevOffset[0] = offset;
|
| 1300 | } else {
|
| 1301 | U32 const ll0 = (llDInfo->baseValue == 0);
|
| 1302 | if (LIKELY((ofBits == 0))) {
|
| 1303 | offset = seqState->prevOffset[ll0];
|
| 1304 | seqState->prevOffset[1] = seqState->prevOffset[!ll0];
|
| 1305 | seqState->prevOffset[0] = offset;
|
| 1306 | } else {
|
| 1307 | offset = ofBase + ll0 + BIT_readBitsFast(&seqState->DStream, 1);
|
| 1308 | { size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
|
| 1309 | temp -= !temp;
|
| 1310 | if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
|
| 1311 | seqState->prevOffset[1] = seqState->prevOffset[0];
|
| 1312 | seqState->prevOffset[0] = offset = temp;
|
| 1313 | } } }
|
| 1314 | seq.offset = offset;
|
| 1315 | }
|
| 1316 |
|
| 1317 | if (mlBits > 0)
|
| 1318 | seq.matchLength += BIT_readBitsFast(&seqState->DStream, mlBits);
|
| 1319 |
|
| 1320 | if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
|
| 1321 | BIT_reloadDStream(&seqState->DStream);
|
| 1322 | if (MEM_64bits() && UNLIKELY(totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
|
| 1323 | BIT_reloadDStream(&seqState->DStream);
|
| 1324 |
|
| 1325 | ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
|
| 1326 |
|
| 1327 | if (llBits > 0)
|
| 1328 | seq.litLength += BIT_readBitsFast(&seqState->DStream, llBits);
|
| 1329 |
|
| 1330 | if (MEM_32bits())
|
| 1331 | BIT_reloadDStream(&seqState->DStream);
|
| 1332 |
|
| 1333 | DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u",
|
| 1334 | (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
|
| 1335 |
|
| 1336 | if (!isLastSeq) {
|
| 1337 |
|
| 1338 | ZSTD_updateFseStateWithDInfo(&seqState->stateLL, &seqState->DStream, llNext, llnbBits);
|
| 1339 | ZSTD_updateFseStateWithDInfo(&seqState->stateML, &seqState->DStream, mlNext, mlnbBits);
|
| 1340 | if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
|
| 1341 | ZSTD_updateFseStateWithDInfo(&seqState->stateOffb, &seqState->DStream, ofNext, ofnbBits);
|
| 1342 | BIT_reloadDStream(&seqState->DStream);
|
| 1343 | }
|
| 1344 | }
|
| 1345 |
|
| 1346 | return seq;
|
| 1347 | }
|
| 1348 |
|
| 1349 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1350 | #if DEBUGLEVEL >= 1
|
| 1351 | static int ZSTD_dictionaryIsActive(ZSTD_DCtx const* dctx, BYTE const* prefixStart, BYTE const* oLitEnd)
|
| 1352 | {
|
| 1353 | size_t const windowSize = dctx->fParams.windowSize;
|
| 1354 |
|
| 1355 | if (dctx->dictContentEndForFuzzing == NULL) return 0;
|
| 1356 |
|
| 1357 | if (prefixStart == dctx->dictContentBeginForFuzzing) return 1;
|
| 1358 |
|
| 1359 | if (dctx->dictEnd != dctx->dictContentEndForFuzzing) return 0;
|
| 1360 |
|
| 1361 | if ((size_t)(oLitEnd - prefixStart) >= windowSize) return 0;
|
| 1362 |
|
| 1363 | return 1;
|
| 1364 | }
|
| 1365 | #endif
|
| 1366 |
|
| 1367 | static void ZSTD_assertValidSequence(
|
| 1368 | ZSTD_DCtx const* dctx,
|
| 1369 | BYTE const* op, BYTE const* oend,
|
| 1370 | seq_t const seq,
|
| 1371 | BYTE const* prefixStart, BYTE const* virtualStart)
|
| 1372 | {
|
| 1373 | #if DEBUGLEVEL >= 1
|
| 1374 | if (dctx->isFrameDecompression) {
|
| 1375 | size_t const windowSize = dctx->fParams.windowSize;
|
| 1376 | size_t const sequenceSize = seq.litLength + seq.matchLength;
|
| 1377 | BYTE const* const oLitEnd = op + seq.litLength;
|
| 1378 | DEBUGLOG(6, "Checking sequence: litL=%u matchL=%u offset=%u",
|
| 1379 | (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
|
| 1380 | assert(op <= oend);
|
| 1381 | assert((size_t)(oend - op) >= sequenceSize);
|
| 1382 | assert(sequenceSize <= ZSTD_blockSizeMax(dctx));
|
| 1383 | if (ZSTD_dictionaryIsActive(dctx, prefixStart, oLitEnd)) {
|
| 1384 | size_t const dictSize = (size_t)((char const*)dctx->dictContentEndForFuzzing - (char const*)dctx->dictContentBeginForFuzzing);
|
| 1385 |
|
| 1386 | assert(seq.offset <= (size_t)(oLitEnd - virtualStart));
|
| 1387 | assert(seq.offset <= windowSize + dictSize);
|
| 1388 | } else {
|
| 1389 |
|
| 1390 | assert(seq.offset <= windowSize);
|
| 1391 | }
|
| 1392 | }
|
| 1393 | #else
|
| 1394 | (void)dctx, (void)op, (void)oend, (void)seq, (void)prefixStart, (void)virtualStart;
|
| 1395 | #endif
|
| 1396 | }
|
| 1397 | #endif
|
| 1398 |
|
| 1399 | #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
|
| 1400 |
|
| 1401 |
|
| 1402 | FORCE_INLINE_TEMPLATE size_t
|
| 1403 | DONT_VECTORIZE
|
| 1404 | ZSTD_decompressSequences_bodySplitLitBuffer( ZSTD_DCtx* dctx,
|
| 1405 | void* dst, size_t maxDstSize,
|
| 1406 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1407 | const ZSTD_longOffset_e isLongOffset)
|
| 1408 | {
|
| 1409 | const BYTE* ip = (const BYTE*)seqStart;
|
| 1410 | const BYTE* const iend = ip + seqSize;
|
| 1411 | BYTE* const ostart = (BYTE*)dst;
|
| 1412 | BYTE* const oend = ZSTD_maybeNullPtrAdd(ostart, maxDstSize);
|
| 1413 | BYTE* op = ostart;
|
| 1414 | const BYTE* litPtr = dctx->litPtr;
|
| 1415 | const BYTE* litBufferEnd = dctx->litBufferEnd;
|
| 1416 | const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
|
| 1417 | const BYTE* const vBase = (const BYTE*) (dctx->virtualStart);
|
| 1418 | const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
|
| 1419 | DEBUGLOG(5, "ZSTD_decompressSequences_bodySplitLitBuffer (%i seqs)", nbSeq);
|
| 1420 |
|
| 1421 |
|
| 1422 | if (nbSeq) {
|
| 1423 | seqState_t seqState;
|
| 1424 | dctx->fseEntropy = 1;
|
| 1425 | { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
|
| 1426 | RETURN_ERROR_IF(
|
| 1427 | ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)),
|
| 1428 | corruption_detected, "");
|
| 1429 | ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
|
| 1430 | ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
|
| 1431 | ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
|
| 1432 | assert(dst != NULL);
|
| 1433 |
|
| 1434 | ZSTD_STATIC_ASSERT(
|
| 1435 | BIT_DStream_unfinished < BIT_DStream_completed &&
|
| 1436 | BIT_DStream_endOfBuffer < BIT_DStream_completed &&
|
| 1437 | BIT_DStream_completed < BIT_DStream_overflow);
|
| 1438 |
|
| 1439 |
|
| 1440 | { seq_t sequence = {0,0,0};
|
| 1441 | |
| 1442 | *
|
| 1443 | * zstd compiled with gcc-9 on an Intel i9-9900k shows 10% decompression
|
| 1444 | * speed swings based on the alignment of the decompression loop. This
|
| 1445 | * performance swing is caused by parts of the decompression loop falling
|
| 1446 | * out of the DSB. The entire decompression loop should fit in the DSB,
|
| 1447 | * when it can't we get much worse performance. You can measure if you've
|
| 1448 | * hit the good case or the bad case with this perf command for some
|
| 1449 | * compressed file test.zst:
|
| 1450 | *
|
| 1451 | * perf stat -e cycles -e instructions -e idq.all_dsb_cycles_any_uops \
|
| 1452 | * -e idq.all_mite_cycles_any_uops -- ./zstd -tq test.zst
|
| 1453 | *
|
| 1454 | * If you see most cycles served out of the MITE you've hit the bad case.
|
| 1455 | * If you see most cycles served out of the DSB you've hit the good case.
|
| 1456 | * If it is pretty even then you may be in an okay case.
|
| 1457 | *
|
| 1458 | * This issue has been reproduced on the following CPUs:
|
| 1459 | * - Kabylake: Macbook Pro (15-inch, 2019) 2.4 GHz Intel Core i9
|
| 1460 | * Use Instruments->Counters to get DSB/MITE cycles.
|
| 1461 | * I never got performance swings, but I was able to
|
| 1462 | * go from the good case of mostly DSB to half of the
|
| 1463 | * cycles served from MITE.
|
| 1464 | * - Coffeelake: Intel i9-9900k
|
| 1465 | * - Coffeelake: Intel i7-9700k
|
| 1466 | *
|
| 1467 | * I haven't been able to reproduce the instability or DSB misses on any
|
| 1468 | * of the following CPUS:
|
| 1469 | * - Haswell
|
| 1470 | * - Broadwell: Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GH
|
| 1471 | * - Skylake
|
| 1472 | *
|
| 1473 | * Alignment is done for each of the three major decompression loops:
|
| 1474 | * - ZSTD_decompressSequences_bodySplitLitBuffer - presplit section of the literal buffer
|
| 1475 | * - ZSTD_decompressSequences_bodySplitLitBuffer - postsplit section of the literal buffer
|
| 1476 | * - ZSTD_decompressSequences_body
|
| 1477 | * Alignment choices are made to minimize large swings on bad cases and influence on performance
|
| 1478 | * from changes external to this code, rather than to overoptimize on the current commit.
|
| 1479 | *
|
| 1480 | * If you are seeing performance stability this script can help test.
|
| 1481 | * It tests on 4 commits in zstd where I saw performance change.
|
| 1482 | *
|
| 1483 | * https://gist.github.com/terrelln/9889fc06a423fd5ca6e99351564473f4
|
| 1484 |
|
| 1485 | #if defined(__x86_64__)
|
| 1486 | __asm__(".p2align 6");
|
| 1487 | # if __GNUC__ >= 7
|
| 1488 |
|
| 1489 | __asm__("nop");
|
| 1490 | __asm__(".p2align 5");
|
| 1491 | __asm__("nop");
|
| 1492 | __asm__(".p2align 4");
|
| 1493 | # if __GNUC__ == 8 || __GNUC__ == 10
|
| 1494 |
|
| 1495 | __asm__("nop");
|
| 1496 | __asm__(".p2align 3");
|
| 1497 | # endif
|
| 1498 | # endif
|
| 1499 | #endif
|
| 1500 |
|
| 1501 |
|
| 1502 | for ( ; nbSeq; nbSeq--) {
|
| 1503 | sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1);
|
| 1504 | if (litPtr + sequence.litLength > dctx->litBufferEnd) break;
|
| 1505 | { size_t const oneSeqSize = ZSTD_execSequenceSplitLitBuffer(op, oend, litPtr + sequence.litLength - WILDCOPY_OVERLENGTH, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd);
|
| 1506 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1507 | assert(!ZSTD_isError(oneSeqSize));
|
| 1508 | ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
|
| 1509 | #endif
|
| 1510 | if (UNLIKELY(ZSTD_isError(oneSeqSize)))
|
| 1511 | return oneSeqSize;
|
| 1512 | DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
|
| 1513 | op += oneSeqSize;
|
| 1514 | } }
|
| 1515 | DEBUGLOG(6, "reached: (litPtr + sequence.litLength > dctx->litBufferEnd)");
|
| 1516 |
|
| 1517 |
|
| 1518 | if (nbSeq > 0) {
|
| 1519 | const size_t leftoverLit = dctx->litBufferEnd - litPtr;
|
| 1520 | DEBUGLOG(6, "There are %i sequences left, and %zu/%zu literals left in buffer", nbSeq, leftoverLit, sequence.litLength);
|
| 1521 | if (leftoverLit) {
|
| 1522 | RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
|
| 1523 | ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit);
|
| 1524 | sequence.litLength -= leftoverLit;
|
| 1525 | op += leftoverLit;
|
| 1526 | }
|
| 1527 | litPtr = dctx->litExtraBuffer;
|
| 1528 | litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
|
| 1529 | dctx->litBufferLocation = ZSTD_not_in_dst;
|
| 1530 | { size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd);
|
| 1531 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1532 | assert(!ZSTD_isError(oneSeqSize));
|
| 1533 | ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
|
| 1534 | #endif
|
| 1535 | if (UNLIKELY(ZSTD_isError(oneSeqSize)))
|
| 1536 | return oneSeqSize;
|
| 1537 | DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
|
| 1538 | op += oneSeqSize;
|
| 1539 | }
|
| 1540 | nbSeq--;
|
| 1541 | }
|
| 1542 | }
|
| 1543 |
|
| 1544 | if (nbSeq > 0) {
|
| 1545 |
|
| 1546 |
|
| 1547 | #if defined(__x86_64__)
|
| 1548 | __asm__(".p2align 6");
|
| 1549 | __asm__("nop");
|
| 1550 | # if __GNUC__ != 7
|
| 1551 |
|
| 1552 | __asm__(".p2align 4");
|
| 1553 | __asm__("nop");
|
| 1554 | __asm__(".p2align 3");
|
| 1555 | # elif __GNUC__ >= 11
|
| 1556 | __asm__(".p2align 3");
|
| 1557 | # else
|
| 1558 | __asm__(".p2align 5");
|
| 1559 | __asm__("nop");
|
| 1560 | __asm__(".p2align 3");
|
| 1561 | # endif
|
| 1562 | #endif
|
| 1563 |
|
| 1564 | for ( ; nbSeq ; nbSeq--) {
|
| 1565 | seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1);
|
| 1566 | size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd);
|
| 1567 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1568 | assert(!ZSTD_isError(oneSeqSize));
|
| 1569 | ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
|
| 1570 | #endif
|
| 1571 | if (UNLIKELY(ZSTD_isError(oneSeqSize)))
|
| 1572 | return oneSeqSize;
|
| 1573 | DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
|
| 1574 | op += oneSeqSize;
|
| 1575 | }
|
| 1576 | }
|
| 1577 |
|
| 1578 |
|
| 1579 | DEBUGLOG(5, "ZSTD_decompressSequences_bodySplitLitBuffer: after decode loop, remaining nbSeq : %i", nbSeq);
|
| 1580 | RETURN_ERROR_IF(nbSeq, corruption_detected, "");
|
| 1581 | DEBUGLOG(5, "bitStream : start=%p, ptr=%p, bitsConsumed=%u", seqState.DStream.start, seqState.DStream.ptr, seqState.DStream.bitsConsumed);
|
| 1582 | RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, "");
|
| 1583 |
|
| 1584 | { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
|
| 1585 | }
|
| 1586 |
|
| 1587 |
|
| 1588 | if (dctx->litBufferLocation == ZSTD_split) {
|
| 1589 |
|
| 1590 | size_t const lastLLSize = (size_t)(litBufferEnd - litPtr);
|
| 1591 | DEBUGLOG(6, "copy last literals from segment : %u", (U32)lastLLSize);
|
| 1592 | RETURN_ERROR_IF(lastLLSize > (size_t)(oend - op), dstSize_tooSmall, "");
|
| 1593 | if (op != NULL) {
|
| 1594 | ZSTD_memmove(op, litPtr, lastLLSize);
|
| 1595 | op += lastLLSize;
|
| 1596 | }
|
| 1597 | litPtr = dctx->litExtraBuffer;
|
| 1598 | litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
|
| 1599 | dctx->litBufferLocation = ZSTD_not_in_dst;
|
| 1600 | }
|
| 1601 |
|
| 1602 | { size_t const lastLLSize = (size_t)(litBufferEnd - litPtr);
|
| 1603 | DEBUGLOG(6, "copy last literals from internal buffer : %u", (U32)lastLLSize);
|
| 1604 | RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, "");
|
| 1605 | if (op != NULL) {
|
| 1606 | ZSTD_memcpy(op, litPtr, lastLLSize);
|
| 1607 | op += lastLLSize;
|
| 1608 | } }
|
| 1609 |
|
| 1610 | DEBUGLOG(6, "decoded block of size %u bytes", (U32)(op - ostart));
|
| 1611 | return (size_t)(op - ostart);
|
| 1612 | }
|
| 1613 |
|
| 1614 | FORCE_INLINE_TEMPLATE size_t
|
| 1615 | DONT_VECTORIZE
|
| 1616 | ZSTD_decompressSequences_body(ZSTD_DCtx* dctx,
|
| 1617 | void* dst, size_t maxDstSize,
|
| 1618 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1619 | const ZSTD_longOffset_e isLongOffset)
|
| 1620 | {
|
| 1621 | const BYTE* ip = (const BYTE*)seqStart;
|
| 1622 | const BYTE* const iend = ip + seqSize;
|
| 1623 | BYTE* const ostart = (BYTE*)dst;
|
| 1624 | BYTE* const oend = dctx->litBufferLocation == ZSTD_not_in_dst ? ZSTD_maybeNullPtrAdd(ostart, maxDstSize) : dctx->litBuffer;
|
| 1625 | BYTE* op = ostart;
|
| 1626 | const BYTE* litPtr = dctx->litPtr;
|
| 1627 | const BYTE* const litEnd = litPtr + dctx->litSize;
|
| 1628 | const BYTE* const prefixStart = (const BYTE*)(dctx->prefixStart);
|
| 1629 | const BYTE* const vBase = (const BYTE*)(dctx->virtualStart);
|
| 1630 | const BYTE* const dictEnd = (const BYTE*)(dctx->dictEnd);
|
| 1631 | DEBUGLOG(5, "ZSTD_decompressSequences_body: nbSeq = %d", nbSeq);
|
| 1632 |
|
| 1633 |
|
| 1634 | if (nbSeq) {
|
| 1635 | seqState_t seqState;
|
| 1636 | dctx->fseEntropy = 1;
|
| 1637 | { U32 i; for (i = 0; i < ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
|
| 1638 | RETURN_ERROR_IF(
|
| 1639 | ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend - ip)),
|
| 1640 | corruption_detected, "");
|
| 1641 | ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
|
| 1642 | ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
|
| 1643 | ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
|
| 1644 | assert(dst != NULL);
|
| 1645 |
|
| 1646 | #if defined(__x86_64__)
|
| 1647 | __asm__(".p2align 6");
|
| 1648 | __asm__("nop");
|
| 1649 | # if __GNUC__ >= 7
|
| 1650 | __asm__(".p2align 5");
|
| 1651 | __asm__("nop");
|
| 1652 | __asm__(".p2align 3");
|
| 1653 | # else
|
| 1654 | __asm__(".p2align 4");
|
| 1655 | __asm__("nop");
|
| 1656 | __asm__(".p2align 3");
|
| 1657 | # endif
|
| 1658 | #endif
|
| 1659 |
|
| 1660 | for ( ; nbSeq ; nbSeq--) {
|
| 1661 | seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1);
|
| 1662 | size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd);
|
| 1663 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1664 | assert(!ZSTD_isError(oneSeqSize));
|
| 1665 | ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
|
| 1666 | #endif
|
| 1667 | if (UNLIKELY(ZSTD_isError(oneSeqSize)))
|
| 1668 | return oneSeqSize;
|
| 1669 | DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
|
| 1670 | op += oneSeqSize;
|
| 1671 | }
|
| 1672 |
|
| 1673 |
|
| 1674 | assert(nbSeq == 0);
|
| 1675 | RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, "");
|
| 1676 |
|
| 1677 | { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
|
| 1678 | }
|
| 1679 |
|
| 1680 |
|
| 1681 | { size_t const lastLLSize = (size_t)(litEnd - litPtr);
|
| 1682 | DEBUGLOG(6, "copy last literals : %u", (U32)lastLLSize);
|
| 1683 | RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, "");
|
| 1684 | if (op != NULL) {
|
| 1685 | ZSTD_memcpy(op, litPtr, lastLLSize);
|
| 1686 | op += lastLLSize;
|
| 1687 | } }
|
| 1688 |
|
| 1689 | DEBUGLOG(6, "decoded block of size %u bytes", (U32)(op - ostart));
|
| 1690 | return (size_t)(op - ostart);
|
| 1691 | }
|
| 1692 |
|
| 1693 | static size_t
|
| 1694 | ZSTD_decompressSequences_default(ZSTD_DCtx* dctx,
|
| 1695 | void* dst, size_t maxDstSize,
|
| 1696 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1697 | const ZSTD_longOffset_e isLongOffset)
|
| 1698 | {
|
| 1699 | return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1700 | }
|
| 1701 |
|
| 1702 | static size_t
|
| 1703 | ZSTD_decompressSequencesSplitLitBuffer_default(ZSTD_DCtx* dctx,
|
| 1704 | void* dst, size_t maxDstSize,
|
| 1705 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1706 | const ZSTD_longOffset_e isLongOffset)
|
| 1707 | {
|
| 1708 | return ZSTD_decompressSequences_bodySplitLitBuffer(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1709 | }
|
| 1710 | #endif
|
| 1711 |
|
| 1712 | #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
|
| 1713 |
|
| 1714 | FORCE_INLINE_TEMPLATE
|
| 1715 |
|
| 1716 | size_t ZSTD_prefetchMatch(size_t prefetchPos, seq_t const sequence,
|
| 1717 | const BYTE* const prefixStart, const BYTE* const dictEnd)
|
| 1718 | {
|
| 1719 | prefetchPos += sequence.litLength;
|
| 1720 | { const BYTE* const matchBase = (sequence.offset > prefetchPos) ? dictEnd : prefixStart;
|
| 1721 | |
| 1722 | * No consequence though : memory address is only used for prefetching, not for dereferencing
|
| 1723 | const BYTE* const match = ZSTD_wrappedPtrSub(ZSTD_wrappedPtrAdd(matchBase, prefetchPos), sequence.offset);
|
| 1724 | PREFETCH_L1(match); PREFETCH_L1(match+CACHELINE_SIZE);
|
| 1725 | }
|
| 1726 | return prefetchPos + sequence.matchLength;
|
| 1727 | }
|
| 1728 |
|
| 1729 | |
| 1730 | * to reduce latency impact of cache misses.
|
| 1731 | * It's generally employed when block contains a significant portion of long-distance matches
|
| 1732 | * or when coupled with a "cold" dictionary
|
| 1733 | FORCE_INLINE_TEMPLATE size_t
|
| 1734 | ZSTD_decompressSequencesLong_body(
|
| 1735 | ZSTD_DCtx* dctx,
|
| 1736 | void* dst, size_t maxDstSize,
|
| 1737 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1738 | const ZSTD_longOffset_e isLongOffset)
|
| 1739 | {
|
| 1740 | const BYTE* ip = (const BYTE*)seqStart;
|
| 1741 | const BYTE* const iend = ip + seqSize;
|
| 1742 | BYTE* const ostart = (BYTE*)dst;
|
| 1743 | BYTE* const oend = dctx->litBufferLocation == ZSTD_in_dst ? dctx->litBuffer : ZSTD_maybeNullPtrAdd(ostart, maxDstSize);
|
| 1744 | BYTE* op = ostart;
|
| 1745 | const BYTE* litPtr = dctx->litPtr;
|
| 1746 | const BYTE* litBufferEnd = dctx->litBufferEnd;
|
| 1747 | const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
|
| 1748 | const BYTE* const dictStart = (const BYTE*) (dctx->virtualStart);
|
| 1749 | const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
|
| 1750 |
|
| 1751 |
|
| 1752 | if (nbSeq) {
|
| 1753 | #define STORED_SEQS 8
|
| 1754 | #define STORED_SEQS_MASK (STORED_SEQS-1)
|
| 1755 | #define ADVANCED_SEQS STORED_SEQS
|
| 1756 | seq_t sequences[STORED_SEQS];
|
| 1757 | int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS);
|
| 1758 | seqState_t seqState;
|
| 1759 | int seqNb;
|
| 1760 | size_t prefetchPos = (size_t)(op-prefixStart);
|
| 1761 |
|
| 1762 | dctx->fseEntropy = 1;
|
| 1763 | { int i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
|
| 1764 | assert(dst != NULL);
|
| 1765 | assert(iend >= ip);
|
| 1766 | RETURN_ERROR_IF(
|
| 1767 | ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)),
|
| 1768 | corruption_detected, "");
|
| 1769 | ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
|
| 1770 | ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
|
| 1771 | ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
|
| 1772 |
|
| 1773 |
|
| 1774 | for (seqNb=0; seqNb<seqAdvance; seqNb++) {
|
| 1775 | seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, seqNb == nbSeq-1);
|
| 1776 | prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
|
| 1777 | sequences[seqNb] = sequence;
|
| 1778 | }
|
| 1779 |
|
| 1780 |
|
| 1781 | for (; seqNb < nbSeq; seqNb++) {
|
| 1782 | seq_t sequence = ZSTD_decodeSequence(&seqState, isLongOffset, seqNb == nbSeq-1);
|
| 1783 |
|
| 1784 | if (dctx->litBufferLocation == ZSTD_split && litPtr + sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength > dctx->litBufferEnd) {
|
| 1785 |
|
| 1786 | const size_t leftoverLit = dctx->litBufferEnd - litPtr;
|
| 1787 | if (leftoverLit)
|
| 1788 | {
|
| 1789 | RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
|
| 1790 | ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit);
|
| 1791 | sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength -= leftoverLit;
|
| 1792 | op += leftoverLit;
|
| 1793 | }
|
| 1794 | litPtr = dctx->litExtraBuffer;
|
| 1795 | litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
|
| 1796 | dctx->litBufferLocation = ZSTD_not_in_dst;
|
| 1797 | { size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd);
|
| 1798 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1799 | assert(!ZSTD_isError(oneSeqSize));
|
| 1800 | ZSTD_assertValidSequence(dctx, op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], prefixStart, dictStart);
|
| 1801 | #endif
|
| 1802 | if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
|
| 1803 |
|
| 1804 | prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
|
| 1805 | sequences[seqNb & STORED_SEQS_MASK] = sequence;
|
| 1806 | op += oneSeqSize;
|
| 1807 | } }
|
| 1808 | else
|
| 1809 | {
|
| 1810 |
|
| 1811 | size_t const oneSeqSize = dctx->litBufferLocation == ZSTD_split ?
|
| 1812 | ZSTD_execSequenceSplitLitBuffer(op, oend, litPtr + sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength - WILDCOPY_OVERLENGTH, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd) :
|
| 1813 | ZSTD_execSequence(op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd);
|
| 1814 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1815 | assert(!ZSTD_isError(oneSeqSize));
|
| 1816 | ZSTD_assertValidSequence(dctx, op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], prefixStart, dictStart);
|
| 1817 | #endif
|
| 1818 | if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
|
| 1819 |
|
| 1820 | prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
|
| 1821 | sequences[seqNb & STORED_SEQS_MASK] = sequence;
|
| 1822 | op += oneSeqSize;
|
| 1823 | }
|
| 1824 | }
|
| 1825 | RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, "");
|
| 1826 |
|
| 1827 |
|
| 1828 | seqNb -= seqAdvance;
|
| 1829 | for ( ; seqNb<nbSeq ; seqNb++) {
|
| 1830 | seq_t *sequence = &(sequences[seqNb&STORED_SEQS_MASK]);
|
| 1831 | if (dctx->litBufferLocation == ZSTD_split && litPtr + sequence->litLength > dctx->litBufferEnd) {
|
| 1832 | const size_t leftoverLit = dctx->litBufferEnd - litPtr;
|
| 1833 | if (leftoverLit) {
|
| 1834 | RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
|
| 1835 | ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit);
|
| 1836 | sequence->litLength -= leftoverLit;
|
| 1837 | op += leftoverLit;
|
| 1838 | }
|
| 1839 | litPtr = dctx->litExtraBuffer;
|
| 1840 | litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
|
| 1841 | dctx->litBufferLocation = ZSTD_not_in_dst;
|
| 1842 | { size_t const oneSeqSize = ZSTD_execSequence(op, oend, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd);
|
| 1843 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1844 | assert(!ZSTD_isError(oneSeqSize));
|
| 1845 | ZSTD_assertValidSequence(dctx, op, oend, sequences[seqNb&STORED_SEQS_MASK], prefixStart, dictStart);
|
| 1846 | #endif
|
| 1847 | if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
|
| 1848 | op += oneSeqSize;
|
| 1849 | }
|
| 1850 | }
|
| 1851 | else
|
| 1852 | {
|
| 1853 | size_t const oneSeqSize = dctx->litBufferLocation == ZSTD_split ?
|
| 1854 | ZSTD_execSequenceSplitLitBuffer(op, oend, litPtr + sequence->litLength - WILDCOPY_OVERLENGTH, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd) :
|
| 1855 | ZSTD_execSequence(op, oend, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd);
|
| 1856 | #if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
|
| 1857 | assert(!ZSTD_isError(oneSeqSize));
|
| 1858 | ZSTD_assertValidSequence(dctx, op, oend, sequences[seqNb&STORED_SEQS_MASK], prefixStart, dictStart);
|
| 1859 | #endif
|
| 1860 | if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
|
| 1861 | op += oneSeqSize;
|
| 1862 | }
|
| 1863 | }
|
| 1864 |
|
| 1865 |
|
| 1866 | { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
|
| 1867 | }
|
| 1868 |
|
| 1869 |
|
| 1870 | if (dctx->litBufferLocation == ZSTD_split) {
|
| 1871 | size_t const lastLLSize = litBufferEnd - litPtr;
|
| 1872 | RETURN_ERROR_IF(lastLLSize > (size_t)(oend - op), dstSize_tooSmall, "");
|
| 1873 | if (op != NULL) {
|
| 1874 | ZSTD_memmove(op, litPtr, lastLLSize);
|
| 1875 | op += lastLLSize;
|
| 1876 | }
|
| 1877 | litPtr = dctx->litExtraBuffer;
|
| 1878 | litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
|
| 1879 | }
|
| 1880 | { size_t const lastLLSize = litBufferEnd - litPtr;
|
| 1881 | RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, "");
|
| 1882 | if (op != NULL) {
|
| 1883 | ZSTD_memmove(op, litPtr, lastLLSize);
|
| 1884 | op += lastLLSize;
|
| 1885 | }
|
| 1886 | }
|
| 1887 |
|
| 1888 | return (size_t)(op - ostart);
|
| 1889 | }
|
| 1890 |
|
| 1891 | static size_t
|
| 1892 | ZSTD_decompressSequencesLong_default(ZSTD_DCtx* dctx,
|
| 1893 | void* dst, size_t maxDstSize,
|
| 1894 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1895 | const ZSTD_longOffset_e isLongOffset)
|
| 1896 | {
|
| 1897 | return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1898 | }
|
| 1899 | #endif
|
| 1900 |
|
| 1901 |
|
| 1902 |
|
| 1903 | #if DYNAMIC_BMI2
|
| 1904 |
|
| 1905 | #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
|
| 1906 | static BMI2_TARGET_ATTRIBUTE size_t
|
| 1907 | DONT_VECTORIZE
|
| 1908 | ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx,
|
| 1909 | void* dst, size_t maxDstSize,
|
| 1910 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1911 | const ZSTD_longOffset_e isLongOffset)
|
| 1912 | {
|
| 1913 | return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1914 | }
|
| 1915 | static BMI2_TARGET_ATTRIBUTE size_t
|
| 1916 | DONT_VECTORIZE
|
| 1917 | ZSTD_decompressSequencesSplitLitBuffer_bmi2(ZSTD_DCtx* dctx,
|
| 1918 | void* dst, size_t maxDstSize,
|
| 1919 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1920 | const ZSTD_longOffset_e isLongOffset)
|
| 1921 | {
|
| 1922 | return ZSTD_decompressSequences_bodySplitLitBuffer(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1923 | }
|
| 1924 | #endif
|
| 1925 |
|
| 1926 | #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
|
| 1927 | static BMI2_TARGET_ATTRIBUTE size_t
|
| 1928 | ZSTD_decompressSequencesLong_bmi2(ZSTD_DCtx* dctx,
|
| 1929 | void* dst, size_t maxDstSize,
|
| 1930 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1931 | const ZSTD_longOffset_e isLongOffset)
|
| 1932 | {
|
| 1933 | return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1934 | }
|
| 1935 | #endif
|
| 1936 |
|
| 1937 | #endif
|
| 1938 |
|
| 1939 | #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
|
| 1940 | static size_t
|
| 1941 | ZSTD_decompressSequences(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize,
|
| 1942 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1943 | const ZSTD_longOffset_e isLongOffset)
|
| 1944 | {
|
| 1945 | DEBUGLOG(5, "ZSTD_decompressSequences");
|
| 1946 | #if DYNAMIC_BMI2
|
| 1947 | if (ZSTD_DCtx_get_bmi2(dctx)) {
|
| 1948 | return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1949 | }
|
| 1950 | #endif
|
| 1951 | return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1952 | }
|
| 1953 | static size_t
|
| 1954 | ZSTD_decompressSequencesSplitLitBuffer(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize,
|
| 1955 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1956 | const ZSTD_longOffset_e isLongOffset)
|
| 1957 | {
|
| 1958 | DEBUGLOG(5, "ZSTD_decompressSequencesSplitLitBuffer");
|
| 1959 | #if DYNAMIC_BMI2
|
| 1960 | if (ZSTD_DCtx_get_bmi2(dctx)) {
|
| 1961 | return ZSTD_decompressSequencesSplitLitBuffer_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1962 | }
|
| 1963 | #endif
|
| 1964 | return ZSTD_decompressSequencesSplitLitBuffer_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1965 | }
|
| 1966 | #endif
|
| 1967 |
|
| 1968 |
|
| 1969 | #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
|
| 1970 | |
| 1971 | * decompression function triggered when a minimum share of offsets is considered "long",
|
| 1972 | * aka out of cache.
|
| 1973 | * note : "long" definition seems overloaded here, sometimes meaning "wider than bitstream register", and sometimes meaning "farther than memory cache distance".
|
| 1974 | * This function will try to mitigate main memory latency through the use of prefetching
|
| 1975 | static size_t
|
| 1976 | ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx,
|
| 1977 | void* dst, size_t maxDstSize,
|
| 1978 | const void* seqStart, size_t seqSize, int nbSeq,
|
| 1979 | const ZSTD_longOffset_e isLongOffset)
|
| 1980 | {
|
| 1981 | DEBUGLOG(5, "ZSTD_decompressSequencesLong");
|
| 1982 | #if DYNAMIC_BMI2
|
| 1983 | if (ZSTD_DCtx_get_bmi2(dctx)) {
|
| 1984 | return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1985 | }
|
| 1986 | #endif
|
| 1987 | return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
|
| 1988 | }
|
| 1989 | #endif
|
| 1990 |
|
| 1991 |
|
| 1992 | |
| 1993 | * @returns The total size of the history referenceable by zstd, including
|
| 1994 | * both the prefix and the extDict. At @p op any offset larger than this
|
| 1995 | * is invalid.
|
| 1996 |
|
| 1997 | static size_t ZSTD_totalHistorySize(BYTE* op, BYTE const* virtualStart)
|
| 1998 | {
|
| 1999 | return (size_t)(op - virtualStart);
|
| 2000 | }
|
| 2001 |
|
| 2002 | typedef struct {
|
| 2003 | unsigned longOffsetShare;
|
| 2004 | unsigned maxNbAdditionalBits;
|
| 2005 | } ZSTD_OffsetInfo;
|
| 2006 |
|
| 2007 | |
| 2008 | * condition : offTable must be valid
|
| 2009 | * @return : "share" of long offsets (arbitrarily defined as > (1<<23))
|
| 2010 | * compared to maximum possible of (1<<OffFSELog),
|
| 2011 | * as well as the maximum number additional bits required.
|
| 2012 |
|
| 2013 | static ZSTD_OffsetInfo
|
| 2014 | ZSTD_getOffsetInfo(const ZSTD_seqSymbol* offTable, int nbSeq)
|
| 2015 | {
|
| 2016 | ZSTD_OffsetInfo info = {0, 0};
|
| 2017 | |
| 2018 | * no sequences, so both values should be 0.
|
| 2019 |
|
| 2020 | if (nbSeq != 0) {
|
| 2021 | const void* ptr = offTable;
|
| 2022 | U32 const tableLog = ((const ZSTD_seqSymbol_header*)ptr)[0].tableLog;
|
| 2023 | const ZSTD_seqSymbol* table = offTable + 1;
|
| 2024 | U32 const max = 1 << tableLog;
|
| 2025 | U32 u;
|
| 2026 | DEBUGLOG(5, "ZSTD_getLongOffsetsShare: (tableLog=%u)", tableLog);
|
| 2027 |
|
| 2028 | assert(max <= (1 << OffFSELog));
|
| 2029 | for (u=0; u<max; u++) {
|
| 2030 | info.maxNbAdditionalBits = MAX(info.maxNbAdditionalBits, table[u].nbAdditionalBits);
|
| 2031 | if (table[u].nbAdditionalBits > 22) info.longOffsetShare += 1;
|
| 2032 | }
|
| 2033 |
|
| 2034 | assert(tableLog <= OffFSELog);
|
| 2035 | info.longOffsetShare <<= (OffFSELog - tableLog);
|
| 2036 | }
|
| 2037 |
|
| 2038 | return info;
|
| 2039 | }
|
| 2040 |
|
| 2041 | |
| 2042 | * @returns The maximum offset we can decode in one read of our bitstream, without
|
| 2043 | * reloading more bits in the middle of the offset bits read. Any offsets larger
|
| 2044 | * than this must use the long offset decoder.
|
| 2045 |
|
| 2046 | static size_t ZSTD_maxShortOffset(void)
|
| 2047 | {
|
| 2048 | if (MEM_64bits()) {
|
| 2049 | |
| 2050 | * This might change if the max window size grows.
|
| 2051 |
|
| 2052 | ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX <= 31);
|
| 2053 | return (size_t)-1;
|
| 2054 | } else {
|
| 2055 | |
| 2056 | * This offBase would require STREAM_ACCUMULATOR_MIN extra bits.
|
| 2057 | * Then we have to subtract ZSTD_REP_NUM to get the maximum possible offset.
|
| 2058 |
|
| 2059 | size_t const maxOffbase = ((size_t)1 << (STREAM_ACCUMULATOR_MIN + 1)) - 1;
|
| 2060 | size_t const maxOffset = maxOffbase - ZSTD_REP_NUM;
|
| 2061 | assert(ZSTD_highbit32((U32)maxOffbase) == STREAM_ACCUMULATOR_MIN);
|
| 2062 | return maxOffset;
|
| 2063 | }
|
| 2064 | }
|
| 2065 |
|
| 2066 | size_t
|
| 2067 | ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
|
| 2068 | void* dst, size_t dstCapacity,
|
| 2069 | const void* src, size_t srcSize, const streaming_operation streaming)
|
| 2070 | {
|
| 2071 | const BYTE* ip = (const BYTE*)src;
|
| 2072 | DEBUGLOG(5, "ZSTD_decompressBlock_internal (cSize : %u)", (unsigned)srcSize);
|
| 2073 |
|
| 2074 | |
| 2075 | * allows compressed block to be sized exactly ZSTD_blockSizeMax(dctx).
|
| 2076 | * This generally does not happen, as it makes little sense,
|
| 2077 | * since an uncompressed block would feature same size and have no decompression cost.
|
| 2078 | * Also, note that decoder from reference libzstd before < v1.5.4
|
| 2079 | * would consider this edge case as an error.
|
| 2080 | * As a consequence, avoid generating compressed blocks of size ZSTD_blockSizeMax(dctx)
|
| 2081 | * for broader compatibility with the deployed ecosystem of zstd decoders
|
| 2082 | RETURN_ERROR_IF(srcSize > ZSTD_blockSizeMax(dctx), srcSize_wrong, "");
|
| 2083 |
|
| 2084 |
|
| 2085 | { size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize, dst, dstCapacity, streaming);
|
| 2086 | DEBUGLOG(5, "ZSTD_decodeLiteralsBlock : cSize=%u, nbLiterals=%zu", (U32)litCSize, dctx->litSize);
|
| 2087 | if (ZSTD_isError(litCSize)) return litCSize;
|
| 2088 | ip += litCSize;
|
| 2089 | srcSize -= litCSize;
|
| 2090 | }
|
| 2091 |
|
| 2092 |
|
| 2093 | {
|
| 2094 | |
| 2095 | * Additionally, take the min with dstCapacity to ensure that the totalHistorySize fits in a size_t.
|
| 2096 |
|
| 2097 | size_t const blockSizeMax = MIN(dstCapacity, ZSTD_blockSizeMax(dctx));
|
| 2098 | size_t const totalHistorySize = ZSTD_totalHistorySize(ZSTD_maybeNullPtrAdd((BYTE*)dst, blockSizeMax), (BYTE const*)dctx->virtualStart);
|
| 2099 | |
| 2100 | * Offsets are long if they are larger than ZSTD_maxShortOffset().
|
| 2101 | * We don't expect that to be the case in 64-bit mode.
|
| 2102 | *
|
| 2103 | * We check here to see if our history is large enough to allow long offsets.
|
| 2104 | * If it isn't, then we can't possible have (valid) long offsets. If the offset
|
| 2105 | * is invalid, then it is okay to read it incorrectly.
|
| 2106 | *
|
| 2107 | * If isLongOffsets is true, then we will later check our decoding table to see
|
| 2108 | * if it is even possible to generate long offsets.
|
| 2109 |
|
| 2110 | ZSTD_longOffset_e isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (totalHistorySize > ZSTD_maxShortOffset()));
|
| 2111 | |
| 2112 | * we use. If neither is defined, we do some inspection and dispatch at
|
| 2113 | * runtime.
|
| 2114 |
|
| 2115 | #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
|
| 2116 | !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
|
| 2117 | int usePrefetchDecoder = dctx->ddictIsCold;
|
| 2118 | #else
|
| 2119 | |
| 2120 | * Otherwise this value is ignored.
|
| 2121 |
|
| 2122 | int usePrefetchDecoder = 1;
|
| 2123 | #endif
|
| 2124 | int nbSeq;
|
| 2125 | size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize);
|
| 2126 | if (ZSTD_isError(seqHSize)) return seqHSize;
|
| 2127 | ip += seqHSize;
|
| 2128 | srcSize -= seqHSize;
|
| 2129 |
|
| 2130 | RETURN_ERROR_IF((dst == NULL || dstCapacity == 0) && nbSeq > 0, dstSize_tooSmall, "NULL not handled");
|
| 2131 | RETURN_ERROR_IF(MEM_64bits() && sizeof(size_t) == sizeof(void*) && (size_t)(-1) - (size_t)dst < (size_t)(1 << 20), dstSize_tooSmall,
|
| 2132 | "invalid dst");
|
| 2133 |
|
| 2134 | |
| 2135 | * compute information about the share of long offsets, and the maximum nbAdditionalBits.
|
| 2136 | * NOTE: could probably use a larger nbSeq limit
|
| 2137 |
|
| 2138 | if (isLongOffset || (!usePrefetchDecoder && (totalHistorySize > (1u << 24)) && (nbSeq > 8))) {
|
| 2139 | ZSTD_OffsetInfo const info = ZSTD_getOffsetInfo(dctx->OFTptr, nbSeq);
|
| 2140 | if (isLongOffset && info.maxNbAdditionalBits <= STREAM_ACCUMULATOR_MIN) {
|
| 2141 | |
| 2142 | * enough, then we know it is impossible to have too long an offset in this block, so we can
|
| 2143 | * use the regular offset decoder.
|
| 2144 |
|
| 2145 | isLongOffset = ZSTD_lo_isRegularOffset;
|
| 2146 | }
|
| 2147 | if (!usePrefetchDecoder) {
|
| 2148 | U32 const minShare = MEM_64bits() ? 7 : 20;
|
| 2149 | usePrefetchDecoder = (info.longOffsetShare >= minShare);
|
| 2150 | }
|
| 2151 | }
|
| 2152 |
|
| 2153 | dctx->ddictIsCold = 0;
|
| 2154 |
|
| 2155 | #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
|
| 2156 | !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
|
| 2157 | if (usePrefetchDecoder) {
|
| 2158 | #else
|
| 2159 | (void)usePrefetchDecoder;
|
| 2160 | {
|
| 2161 | #endif
|
| 2162 | #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
|
| 2163 | return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
|
| 2164 | #endif
|
| 2165 | }
|
| 2166 |
|
| 2167 | #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
|
| 2168 |
|
| 2169 | if (dctx->litBufferLocation == ZSTD_split)
|
| 2170 | return ZSTD_decompressSequencesSplitLitBuffer(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
|
| 2171 | else
|
| 2172 | return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
|
| 2173 | #endif
|
| 2174 | }
|
| 2175 | }
|
| 2176 |
|
| 2177 |
|
| 2178 | ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
|
| 2179 | void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize)
|
| 2180 | {
|
| 2181 | if (dst != dctx->previousDstEnd && dstSize > 0) {
|
| 2182 | dctx->dictEnd = dctx->previousDstEnd;
|
| 2183 | dctx->virtualStart = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
|
| 2184 | dctx->prefixStart = dst;
|
| 2185 | dctx->previousDstEnd = dst;
|
| 2186 | }
|
| 2187 | }
|
| 2188 |
|
| 2189 |
|
| 2190 | size_t ZSTD_decompressBlock_deprecated(ZSTD_DCtx* dctx,
|
| 2191 | void* dst, size_t dstCapacity,
|
| 2192 | const void* src, size_t srcSize)
|
| 2193 | {
|
| 2194 | size_t dSize;
|
| 2195 | dctx->isFrameDecompression = 0;
|
| 2196 | ZSTD_checkContinuity(dctx, dst, dstCapacity);
|
| 2197 | dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, not_streaming);
|
| 2198 | FORWARD_IF_ERROR(dSize, "");
|
| 2199 | dctx->previousDstEnd = (char*)dst + dSize;
|
| 2200 | return dSize;
|
| 2201 | }
|
| 2202 |
|
| 2203 |
|
| 2204 |
|
| 2205 | size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx,
|
| 2206 | void* dst, size_t dstCapacity,
|
| 2207 | const void* src, size_t srcSize)
|
| 2208 | {
|
| 2209 | return ZSTD_decompressBlock_deprecated(dctx, dst, dstCapacity, src, srcSize);
|
| 2210 | }
|