From d8bbc7858622b6d9c278469aab701ca0b609cddf Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 15 May 2024 05:35:49 +0200 Subject: Merging upstream version 126.0. Signed-off-by: Daniel Baumann --- third_party/zstd/lib/decompress/huf_decompress.c | 1944 ++++++++++++++++ .../zstd/lib/decompress/huf_decompress_amd64.S | 595 +++++ third_party/zstd/lib/decompress/zstd_ddict.c | 244 ++ third_party/zstd/lib/decompress/zstd_ddict.h | 44 + third_party/zstd/lib/decompress/zstd_decompress.c | 2407 ++++++++++++++++++++ .../zstd/lib/decompress/zstd_decompress_block.c | 2215 ++++++++++++++++++ .../zstd/lib/decompress/zstd_decompress_block.h | 73 + .../zstd/lib/decompress/zstd_decompress_internal.h | 240 ++ 8 files changed, 7762 insertions(+) create mode 100644 third_party/zstd/lib/decompress/huf_decompress.c create mode 100644 third_party/zstd/lib/decompress/huf_decompress_amd64.S create mode 100644 third_party/zstd/lib/decompress/zstd_ddict.c create mode 100644 third_party/zstd/lib/decompress/zstd_ddict.h create mode 100644 third_party/zstd/lib/decompress/zstd_decompress.c create mode 100644 third_party/zstd/lib/decompress/zstd_decompress_block.c create mode 100644 third_party/zstd/lib/decompress/zstd_decompress_block.h create mode 100644 third_party/zstd/lib/decompress/zstd_decompress_internal.h (limited to 'third_party/zstd/lib/decompress') diff --git a/third_party/zstd/lib/decompress/huf_decompress.c b/third_party/zstd/lib/decompress/huf_decompress.c new file mode 100644 index 0000000000..f85dd0beea --- /dev/null +++ b/third_party/zstd/lib/decompress/huf_decompress.c @@ -0,0 +1,1944 @@ +/* ****************************************************************** + * huff0 huffman decoder, + * part of Finite State Entropy library + * Copyright (c) Meta Platforms, Inc. and affiliates. + * + * You can contact the author at : + * - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. +****************************************************************** */ + +/* ************************************************************** +* Dependencies +****************************************************************/ +#include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memset */ +#include "../common/compiler.h" +#include "../common/bitstream.h" /* BIT_* */ +#include "../common/fse.h" /* to compress headers */ +#include "../common/huf.h" +#include "../common/error_private.h" +#include "../common/zstd_internal.h" +#include "../common/bits.h" /* ZSTD_highbit32, ZSTD_countTrailingZeros64 */ + +/* ************************************************************** +* Constants +****************************************************************/ + +#define HUF_DECODER_FAST_TABLELOG 11 + +/* ************************************************************** +* Macros +****************************************************************/ + +#ifdef HUF_DISABLE_FAST_DECODE +# define HUF_ENABLE_FAST_DECODE 0 +#else +# define HUF_ENABLE_FAST_DECODE 1 +#endif + +/* These two optional macros force the use one way or another of the two + * Huffman decompression implementations. You can't force in both directions + * at the same time. + */ +#if defined(HUF_FORCE_DECOMPRESS_X1) && \ + defined(HUF_FORCE_DECOMPRESS_X2) +#error "Cannot force the use of the X1 and X2 decoders at the same time!" +#endif + +/* When DYNAMIC_BMI2 is enabled, fast decoders are only called when bmi2 is + * supported at runtime, so we can add the BMI2 target attribute. + * When it is disabled, we will still get BMI2 if it is enabled statically. + */ +#if DYNAMIC_BMI2 +# define HUF_FAST_BMI2_ATTRS BMI2_TARGET_ATTRIBUTE +#else +# define HUF_FAST_BMI2_ATTRS +#endif + +#ifdef __cplusplus +# define HUF_EXTERN_C extern "C" +#else +# define HUF_EXTERN_C +#endif +#define HUF_ASM_DECL HUF_EXTERN_C + +#if DYNAMIC_BMI2 +# define HUF_NEED_BMI2_FUNCTION 1 +#else +# define HUF_NEED_BMI2_FUNCTION 0 +#endif + +/* ************************************************************** +* Error Management +****************************************************************/ +#define HUF_isError ERR_isError + + +/* ************************************************************** +* Byte alignment for workSpace management +****************************************************************/ +#define HUF_ALIGN(x, a) HUF_ALIGN_MASK((x), (a) - 1) +#define HUF_ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask)) + + +/* ************************************************************** +* BMI2 Variant Wrappers +****************************************************************/ +typedef size_t (*HUF_DecompressUsingDTableFn)(void *dst, size_t dstSize, + const void *cSrc, + size_t cSrcSize, + const HUF_DTable *DTable); + +#if DYNAMIC_BMI2 + +#define HUF_DGEN(fn) \ + \ + static size_t fn##_default( \ + void* dst, size_t dstSize, \ + const void* cSrc, size_t cSrcSize, \ + const HUF_DTable* DTable) \ + { \ + return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable); \ + } \ + \ + static BMI2_TARGET_ATTRIBUTE size_t fn##_bmi2( \ + void* dst, size_t dstSize, \ + const void* cSrc, size_t cSrcSize, \ + const HUF_DTable* DTable) \ + { \ + return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable); \ + } \ + \ + static size_t fn(void* dst, size_t dstSize, void const* cSrc, \ + size_t cSrcSize, HUF_DTable const* DTable, int flags) \ + { \ + if (flags & HUF_flags_bmi2) { \ + return fn##_bmi2(dst, dstSize, cSrc, cSrcSize, DTable); \ + } \ + return fn##_default(dst, dstSize, cSrc, cSrcSize, DTable); \ + } + +#else + +#define HUF_DGEN(fn) \ + static size_t fn(void* dst, size_t dstSize, void const* cSrc, \ + size_t cSrcSize, HUF_DTable const* DTable, int flags) \ + { \ + (void)flags; \ + return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable); \ + } + +#endif + + +/*-***************************/ +/* generic DTableDesc */ +/*-***************************/ +typedef struct { BYTE maxTableLog; BYTE tableType; BYTE tableLog; BYTE reserved; } DTableDesc; + +static DTableDesc HUF_getDTableDesc(const HUF_DTable* table) +{ + DTableDesc dtd; + ZSTD_memcpy(&dtd, table, sizeof(dtd)); + return dtd; +} + +static size_t HUF_initFastDStream(BYTE const* ip) { + BYTE const lastByte = ip[7]; + size_t const bitsConsumed = lastByte ? 8 - ZSTD_highbit32(lastByte) : 0; + size_t const value = MEM_readLEST(ip) | 1; + assert(bitsConsumed <= 8); + assert(sizeof(size_t) == 8); + return value << bitsConsumed; +} + + +/** + * The input/output arguments to the Huffman fast decoding loop: + * + * ip [in/out] - The input pointers, must be updated to reflect what is consumed. + * op [in/out] - The output pointers, must be updated to reflect what is written. + * bits [in/out] - The bitstream containers, must be updated to reflect the current state. + * dt [in] - The decoding table. + * ilowest [in] - The beginning of the valid range of the input. Decoders may read + * down to this pointer. It may be below iend[0]. + * oend [in] - The end of the output stream. op[3] must not cross oend. + * iend [in] - The end of each input stream. ip[i] may cross iend[i], + * as long as it is above ilowest, but that indicates corruption. + */ +typedef struct { + BYTE const* ip[4]; + BYTE* op[4]; + U64 bits[4]; + void const* dt; + BYTE const* ilowest; + BYTE* oend; + BYTE const* iend[4]; +} HUF_DecompressFastArgs; + +typedef void (*HUF_DecompressFastLoopFn)(HUF_DecompressFastArgs*); + +/** + * Initializes args for the fast decoding loop. + * @returns 1 on success + * 0 if the fallback implementation should be used. + * Or an error code on failure. + */ +static size_t HUF_DecompressFastArgs_init(HUF_DecompressFastArgs* args, void* dst, size_t dstSize, void const* src, size_t srcSize, const HUF_DTable* DTable) +{ + void const* dt = DTable + 1; + U32 const dtLog = HUF_getDTableDesc(DTable).tableLog; + + const BYTE* const istart = (const BYTE*)src; + + BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize); + + /* The fast decoding loop assumes 64-bit little-endian. + * This condition is false on x32. + */ + if (!MEM_isLittleEndian() || MEM_32bits()) + return 0; + + /* Avoid nullptr addition */ + if (dstSize == 0) + return 0; + assert(dst != NULL); + + /* strict minimum : jump table + 1 byte per stream */ + if (srcSize < 10) + return ERROR(corruption_detected); + + /* Must have at least 8 bytes per stream because we don't handle initializing smaller bit containers. + * If table log is not correct at this point, fallback to the old decoder. + * On small inputs we don't have enough data to trigger the fast loop, so use the old decoder. + */ + if (dtLog != HUF_DECODER_FAST_TABLELOG) + return 0; + + /* Read the jump table. */ + { + size_t const length1 = MEM_readLE16(istart); + size_t const length2 = MEM_readLE16(istart+2); + size_t const length3 = MEM_readLE16(istart+4); + size_t const length4 = srcSize - (length1 + length2 + length3 + 6); + args->iend[0] = istart + 6; /* jumpTable */ + args->iend[1] = args->iend[0] + length1; + args->iend[2] = args->iend[1] + length2; + args->iend[3] = args->iend[2] + length3; + + /* HUF_initFastDStream() requires this, and this small of an input + * won't benefit from the ASM loop anyways. + */ + if (length1 < 8 || length2 < 8 || length3 < 8 || length4 < 8) + return 0; + if (length4 > srcSize) return ERROR(corruption_detected); /* overflow */ + } + /* ip[] contains the position that is currently loaded into bits[]. */ + args->ip[0] = args->iend[1] - sizeof(U64); + args->ip[1] = args->iend[2] - sizeof(U64); + args->ip[2] = args->iend[3] - sizeof(U64); + args->ip[3] = (BYTE const*)src + srcSize - sizeof(U64); + + /* op[] contains the output pointers. */ + args->op[0] = (BYTE*)dst; + args->op[1] = args->op[0] + (dstSize+3)/4; + args->op[2] = args->op[1] + (dstSize+3)/4; + args->op[3] = args->op[2] + (dstSize+3)/4; + + /* No point to call the ASM loop for tiny outputs. */ + if (args->op[3] >= oend) + return 0; + + /* bits[] is the bit container. + * It is read from the MSB down to the LSB. + * It is shifted left as it is read, and zeros are + * shifted in. After the lowest valid bit a 1 is + * set, so that CountTrailingZeros(bits[]) can be used + * to count how many bits we've consumed. + */ + args->bits[0] = HUF_initFastDStream(args->ip[0]); + args->bits[1] = HUF_initFastDStream(args->ip[1]); + args->bits[2] = HUF_initFastDStream(args->ip[2]); + args->bits[3] = HUF_initFastDStream(args->ip[3]); + + /* The decoders must be sure to never read beyond ilowest. + * This is lower than iend[0], but allowing decoders to read + * down to ilowest can allow an extra iteration or two in the + * fast loop. + */ + args->ilowest = istart; + + args->oend = oend; + args->dt = dt; + + return 1; +} + +static size_t HUF_initRemainingDStream(BIT_DStream_t* bit, HUF_DecompressFastArgs const* args, int stream, BYTE* segmentEnd) +{ + /* Validate that we haven't overwritten. */ + if (args->op[stream] > segmentEnd) + return ERROR(corruption_detected); + /* Validate that we haven't read beyond iend[]. + * Note that ip[] may be < iend[] because the MSB is + * the next bit to read, and we may have consumed 100% + * of the stream, so down to iend[i] - 8 is valid. + */ + if (args->ip[stream] < args->iend[stream] - 8) + return ERROR(corruption_detected); + + /* Construct the BIT_DStream_t. */ + assert(sizeof(size_t) == 8); + bit->bitContainer = MEM_readLEST(args->ip[stream]); + bit->bitsConsumed = ZSTD_countTrailingZeros64(args->bits[stream]); + bit->start = (const char*)args->ilowest; + bit->limitPtr = bit->start + sizeof(size_t); + bit->ptr = (const char*)args->ip[stream]; + + return 0; +} + +/* Calls X(N) for each stream 0, 1, 2, 3. */ +#define HUF_4X_FOR_EACH_STREAM(X) \ + do { \ + X(0); \ + X(1); \ + X(2); \ + X(3); \ + } while (0) + +/* Calls X(N, var) for each stream 0, 1, 2, 3. */ +#define HUF_4X_FOR_EACH_STREAM_WITH_VAR(X, var) \ + do { \ + X(0, (var)); \ + X(1, (var)); \ + X(2, (var)); \ + X(3, (var)); \ + } while (0) + + +#ifndef HUF_FORCE_DECOMPRESS_X2 + +/*-***************************/ +/* single-symbol decoding */ +/*-***************************/ +typedef struct { BYTE nbBits; BYTE byte; } HUF_DEltX1; /* single-symbol decoding */ + +/** + * Packs 4 HUF_DEltX1 structs into a U64. This is used to lay down 4 entries at + * a time. + */ +static U64 HUF_DEltX1_set4(BYTE symbol, BYTE nbBits) { + U64 D4; + if (MEM_isLittleEndian()) { + D4 = (U64)((symbol << 8) + nbBits); + } else { + D4 = (U64)(symbol + (nbBits << 8)); + } + assert(D4 < (1U << 16)); + D4 *= 0x0001000100010001ULL; + return D4; +} + +/** + * Increase the tableLog to targetTableLog and rescales the stats. + * If tableLog > targetTableLog this is a no-op. + * @returns New tableLog + */ +static U32 HUF_rescaleStats(BYTE* huffWeight, U32* rankVal, U32 nbSymbols, U32 tableLog, U32 targetTableLog) +{ + if (tableLog > targetTableLog) + return tableLog; + if (tableLog < targetTableLog) { + U32 const scale = targetTableLog - tableLog; + U32 s; + /* Increase the weight for all non-zero probability symbols by scale. */ + for (s = 0; s < nbSymbols; ++s) { + huffWeight[s] += (BYTE)((huffWeight[s] == 0) ? 0 : scale); + } + /* Update rankVal to reflect the new weights. + * All weights except 0 get moved to weight + scale. + * Weights [1, scale] are empty. + */ + for (s = targetTableLog; s > scale; --s) { + rankVal[s] = rankVal[s - scale]; + } + for (s = scale; s > 0; --s) { + rankVal[s] = 0; + } + } + return targetTableLog; +} + +typedef struct { + U32 rankVal[HUF_TABLELOG_ABSOLUTEMAX + 1]; + U32 rankStart[HUF_TABLELOG_ABSOLUTEMAX + 1]; + U32 statsWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32]; + BYTE symbols[HUF_SYMBOLVALUE_MAX + 1]; + BYTE huffWeight[HUF_SYMBOLVALUE_MAX + 1]; +} HUF_ReadDTableX1_Workspace; + +size_t HUF_readDTableX1_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize, int flags) +{ + U32 tableLog = 0; + U32 nbSymbols = 0; + size_t iSize; + void* const dtPtr = DTable + 1; + HUF_DEltX1* const dt = (HUF_DEltX1*)dtPtr; + HUF_ReadDTableX1_Workspace* wksp = (HUF_ReadDTableX1_Workspace*)workSpace; + + DEBUG_STATIC_ASSERT(HUF_DECOMPRESS_WORKSPACE_SIZE >= sizeof(*wksp)); + if (sizeof(*wksp) > wkspSize) return ERROR(tableLog_tooLarge); + + DEBUG_STATIC_ASSERT(sizeof(DTableDesc) == sizeof(HUF_DTable)); + /* ZSTD_memset(huffWeight, 0, sizeof(huffWeight)); */ /* is not necessary, even though some analyzer complain ... */ + + iSize = HUF_readStats_wksp(wksp->huffWeight, HUF_SYMBOLVALUE_MAX + 1, wksp->rankVal, &nbSymbols, &tableLog, src, srcSize, wksp->statsWksp, sizeof(wksp->statsWksp), flags); + if (HUF_isError(iSize)) return iSize; + + + /* Table header */ + { DTableDesc dtd = HUF_getDTableDesc(DTable); + U32 const maxTableLog = dtd.maxTableLog + 1; + U32 const targetTableLog = MIN(maxTableLog, HUF_DECODER_FAST_TABLELOG); + tableLog = HUF_rescaleStats(wksp->huffWeight, wksp->rankVal, nbSymbols, tableLog, targetTableLog); + if (tableLog > (U32)(dtd.maxTableLog+1)) return ERROR(tableLog_tooLarge); /* DTable too small, Huffman tree cannot fit in */ + dtd.tableType = 0; + dtd.tableLog = (BYTE)tableLog; + ZSTD_memcpy(DTable, &dtd, sizeof(dtd)); + } + + /* Compute symbols and rankStart given rankVal: + * + * rankVal already contains the number of values of each weight. + * + * symbols contains the symbols ordered by weight. First are the rankVal[0] + * weight 0 symbols, followed by the rankVal[1] weight 1 symbols, and so on. + * symbols[0] is filled (but unused) to avoid a branch. + * + * rankStart contains the offset where each rank belongs in the DTable. + * rankStart[0] is not filled because there are no entries in the table for + * weight 0. + */ + { int n; + U32 nextRankStart = 0; + int const unroll = 4; + int const nLimit = (int)nbSymbols - unroll + 1; + for (n=0; n<(int)tableLog+1; n++) { + U32 const curr = nextRankStart; + nextRankStart += wksp->rankVal[n]; + wksp->rankStart[n] = curr; + } + for (n=0; n < nLimit; n += unroll) { + int u; + for (u=0; u < unroll; ++u) { + size_t const w = wksp->huffWeight[n+u]; + wksp->symbols[wksp->rankStart[w]++] = (BYTE)(n+u); + } + } + for (; n < (int)nbSymbols; ++n) { + size_t const w = wksp->huffWeight[n]; + wksp->symbols[wksp->rankStart[w]++] = (BYTE)n; + } + } + + /* fill DTable + * We fill all entries of each weight in order. + * That way length is a constant for each iteration of the outer loop. + * We can switch based on the length to a different inner loop which is + * optimized for that particular case. + */ + { U32 w; + int symbol = wksp->rankVal[0]; + int rankStart = 0; + for (w=1; wrankVal[w]; + int const length = (1 << w) >> 1; + int uStart = rankStart; + BYTE const nbBits = (BYTE)(tableLog + 1 - w); + int s; + int u; + switch (length) { + case 1: + for (s=0; ssymbols[symbol + s]; + D.nbBits = nbBits; + dt[uStart] = D; + uStart += 1; + } + break; + case 2: + for (s=0; ssymbols[symbol + s]; + D.nbBits = nbBits; + dt[uStart+0] = D; + dt[uStart+1] = D; + uStart += 2; + } + break; + case 4: + for (s=0; ssymbols[symbol + s], nbBits); + MEM_write64(dt + uStart, D4); + uStart += 4; + } + break; + case 8: + for (s=0; ssymbols[symbol + s], nbBits); + MEM_write64(dt + uStart, D4); + MEM_write64(dt + uStart + 4, D4); + uStart += 8; + } + break; + default: + for (s=0; ssymbols[symbol + s], nbBits); + for (u=0; u < length; u += 16) { + MEM_write64(dt + uStart + u + 0, D4); + MEM_write64(dt + uStart + u + 4, D4); + MEM_write64(dt + uStart + u + 8, D4); + MEM_write64(dt + uStart + u + 12, D4); + } + assert(u == length); + uStart += length; + } + break; + } + symbol += symbolCount; + rankStart += symbolCount * length; + } + } + return iSize; +} + +FORCE_INLINE_TEMPLATE BYTE +HUF_decodeSymbolX1(BIT_DStream_t* Dstream, const HUF_DEltX1* dt, const U32 dtLog) +{ + size_t const val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */ + BYTE const c = dt[val].byte; + BIT_skipBits(Dstream, dt[val].nbBits); + return c; +} + +#define HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr) \ + do { *ptr++ = HUF_decodeSymbolX1(DStreamPtr, dt, dtLog); } while (0) + +#define HUF_DECODE_SYMBOLX1_1(ptr, DStreamPtr) \ + do { \ + if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \ + HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr); \ + } while (0) + +#define HUF_DECODE_SYMBOLX1_2(ptr, DStreamPtr) \ + do { \ + if (MEM_64bits()) \ + HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr); \ + } while (0) + +HINT_INLINE size_t +HUF_decodeStreamX1(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX1* const dt, const U32 dtLog) +{ + BYTE* const pStart = p; + + /* up to 4 symbols at a time */ + if ((pEnd - p) > 3) { + while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-3)) { + HUF_DECODE_SYMBOLX1_2(p, bitDPtr); + HUF_DECODE_SYMBOLX1_1(p, bitDPtr); + HUF_DECODE_SYMBOLX1_2(p, bitDPtr); + HUF_DECODE_SYMBOLX1_0(p, bitDPtr); + } + } else { + BIT_reloadDStream(bitDPtr); + } + + /* [0-3] symbols remaining */ + if (MEM_32bits()) + while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd)) + HUF_DECODE_SYMBOLX1_0(p, bitDPtr); + + /* no more data to retrieve from bitstream, no need to reload */ + while (p < pEnd) + HUF_DECODE_SYMBOLX1_0(p, bitDPtr); + + return (size_t)(pEnd-pStart); +} + +FORCE_INLINE_TEMPLATE size_t +HUF_decompress1X1_usingDTable_internal_body( + void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + const HUF_DTable* DTable) +{ + BYTE* op = (BYTE*)dst; + BYTE* const oend = ZSTD_maybeNullPtrAdd(op, dstSize); + const void* dtPtr = DTable + 1; + const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr; + BIT_DStream_t bitD; + DTableDesc const dtd = HUF_getDTableDesc(DTable); + U32 const dtLog = dtd.tableLog; + + CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) ); + + HUF_decodeStreamX1(op, &bitD, oend, dt, dtLog); + + if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected); + + return dstSize; +} + +/* HUF_decompress4X1_usingDTable_internal_body(): + * Conditions : + * @dstSize >= 6 + */ +FORCE_INLINE_TEMPLATE size_t +HUF_decompress4X1_usingDTable_internal_body( + void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + const HUF_DTable* DTable) +{ + /* Check */ + if (cSrcSize < 10) return ERROR(corruption_detected); /* strict minimum : jump table + 1 byte per stream */ + if (dstSize < 6) return ERROR(corruption_detected); /* stream 4-split doesn't work */ + + { const BYTE* const istart = (const BYTE*) cSrc; + BYTE* const ostart = (BYTE*) dst; + BYTE* const oend = ostart + dstSize; + BYTE* const olimit = oend - 3; + const void* const dtPtr = DTable + 1; + const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr; + + /* Init */ + BIT_DStream_t bitD1; + BIT_DStream_t bitD2; + BIT_DStream_t bitD3; + BIT_DStream_t bitD4; + size_t const length1 = MEM_readLE16(istart); + size_t const length2 = MEM_readLE16(istart+2); + size_t const length3 = MEM_readLE16(istart+4); + size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6); + const BYTE* const istart1 = istart + 6; /* jumpTable */ + const BYTE* const istart2 = istart1 + length1; + const BYTE* const istart3 = istart2 + length2; + const BYTE* const istart4 = istart3 + length3; + const size_t segmentSize = (dstSize+3) / 4; + BYTE* const opStart2 = ostart + segmentSize; + BYTE* const opStart3 = opStart2 + segmentSize; + BYTE* const opStart4 = opStart3 + segmentSize; + BYTE* op1 = ostart; + BYTE* op2 = opStart2; + BYTE* op3 = opStart3; + BYTE* op4 = opStart4; + DTableDesc const dtd = HUF_getDTableDesc(DTable); + U32 const dtLog = dtd.tableLog; + U32 endSignal = 1; + + if (length4 > cSrcSize) return ERROR(corruption_detected); /* overflow */ + if (opStart4 > oend) return ERROR(corruption_detected); /* overflow */ + assert(dstSize >= 6); /* validated above */ + CHECK_F( BIT_initDStream(&bitD1, istart1, length1) ); + CHECK_F( BIT_initDStream(&bitD2, istart2, length2) ); + CHECK_F( BIT_initDStream(&bitD3, istart3, length3) ); + CHECK_F( BIT_initDStream(&bitD4, istart4, length4) ); + + /* up to 16 symbols per loop (4 symbols per stream) in 64-bit mode */ + if ((size_t)(oend - op4) >= sizeof(size_t)) { + for ( ; (endSignal) & (op4 < olimit) ; ) { + HUF_DECODE_SYMBOLX1_2(op1, &bitD1); + HUF_DECODE_SYMBOLX1_2(op2, &bitD2); + HUF_DECODE_SYMBOLX1_2(op3, &bitD3); + HUF_DECODE_SYMBOLX1_2(op4, &bitD4); + HUF_DECODE_SYMBOLX1_1(op1, &bitD1); + HUF_DECODE_SYMBOLX1_1(op2, &bitD2); + HUF_DECODE_SYMBOLX1_1(op3, &bitD3); + HUF_DECODE_SYMBOLX1_1(op4, &bitD4); + HUF_DECODE_SYMBOLX1_2(op1, &bitD1); + HUF_DECODE_SYMBOLX1_2(op2, &bitD2); + HUF_DECODE_SYMBOLX1_2(op3, &bitD3); + HUF_DECODE_SYMBOLX1_2(op4, &bitD4); + HUF_DECODE_SYMBOLX1_0(op1, &bitD1); + HUF_DECODE_SYMBOLX1_0(op2, &bitD2); + HUF_DECODE_SYMBOLX1_0(op3, &bitD3); + HUF_DECODE_SYMBOLX1_0(op4, &bitD4); + endSignal &= BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished; + endSignal &= BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished; + endSignal &= BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished; + endSignal &= BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished; + } + } + + /* check corruption */ + /* note : should not be necessary : op# advance in lock step, and we control op4. + * but curiously, binary generated by gcc 7.2 & 7.3 with -mbmi2 runs faster when >=1 test is present */ + if (op1 > opStart2) return ERROR(corruption_detected); + if (op2 > opStart3) return ERROR(corruption_detected); + if (op3 > opStart4) return ERROR(corruption_detected); + /* note : op4 supposed already verified within main loop */ + + /* finish bitStreams one by one */ + HUF_decodeStreamX1(op1, &bitD1, opStart2, dt, dtLog); + HUF_decodeStreamX1(op2, &bitD2, opStart3, dt, dtLog); + HUF_decodeStreamX1(op3, &bitD3, opStart4, dt, dtLog); + HUF_decodeStreamX1(op4, &bitD4, oend, dt, dtLog); + + /* check */ + { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4); + if (!endCheck) return ERROR(corruption_detected); } + + /* decoded size */ + return dstSize; + } +} + +#if HUF_NEED_BMI2_FUNCTION +static BMI2_TARGET_ATTRIBUTE +size_t HUF_decompress4X1_usingDTable_internal_bmi2(void* dst, size_t dstSize, void const* cSrc, + size_t cSrcSize, HUF_DTable const* DTable) { + return HUF_decompress4X1_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable); +} +#endif + +static +size_t HUF_decompress4X1_usingDTable_internal_default(void* dst, size_t dstSize, void const* cSrc, + size_t cSrcSize, HUF_DTable const* DTable) { + return HUF_decompress4X1_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable); +} + +#if ZSTD_ENABLE_ASM_X86_64_BMI2 + +HUF_ASM_DECL void HUF_decompress4X1_usingDTable_internal_fast_asm_loop(HUF_DecompressFastArgs* args) ZSTDLIB_HIDDEN; + +#endif + +static HUF_FAST_BMI2_ATTRS +void HUF_decompress4X1_usingDTable_internal_fast_c_loop(HUF_DecompressFastArgs* args) +{ + U64 bits[4]; + BYTE const* ip[4]; + BYTE* op[4]; + U16 const* const dtable = (U16 const*)args->dt; + BYTE* const oend = args->oend; + BYTE const* const ilowest = args->ilowest; + + /* Copy the arguments to local variables */ + ZSTD_memcpy(&bits, &args->bits, sizeof(bits)); + ZSTD_memcpy((void*)(&ip), &args->ip, sizeof(ip)); + ZSTD_memcpy(&op, &args->op, sizeof(op)); + + assert(MEM_isLittleEndian()); + assert(!MEM_32bits()); + + for (;;) { + BYTE* olimit; + int stream; + + /* Assert loop preconditions */ +#ifndef NDEBUG + for (stream = 0; stream < 4; ++stream) { + assert(op[stream] <= (stream == 3 ? oend : op[stream + 1])); + assert(ip[stream] >= ilowest); + } +#endif + /* Compute olimit */ + { + /* Each iteration produces 5 output symbols per stream */ + size_t const oiters = (size_t)(oend - op[3]) / 5; + /* Each iteration consumes up to 11 bits * 5 = 55 bits < 7 bytes + * per stream. + */ + size_t const iiters = (size_t)(ip[0] - ilowest) / 7; + /* We can safely run iters iterations before running bounds checks */ + size_t const iters = MIN(oiters, iiters); + size_t const symbols = iters * 5; + + /* We can simply check that op[3] < olimit, instead of checking all + * of our bounds, since we can't hit the other bounds until we've run + * iters iterations, which only happens when op[3] == olimit. + */ + olimit = op[3] + symbols; + + /* Exit fast decoding loop once we reach the end. */ + if (op[3] == olimit) + break; + + /* Exit the decoding loop if any input pointer has crossed the + * previous one. This indicates corruption, and a precondition + * to our loop is that ip[i] >= ip[0]. + */ + for (stream = 1; stream < 4; ++stream) { + if (ip[stream] < ip[stream - 1]) + goto _out; + } + } + +#ifndef NDEBUG + for (stream = 1; stream < 4; ++stream) { + assert(ip[stream] >= ip[stream - 1]); + } +#endif + +#define HUF_4X1_DECODE_SYMBOL(_stream, _symbol) \ + do { \ + int const index = (int)(bits[(_stream)] >> 53); \ + int const entry = (int)dtable[index]; \ + bits[(_stream)] <<= (entry & 0x3F); \ + op[(_stream)][(_symbol)] = (BYTE)((entry >> 8) & 0xFF); \ + } while (0) + +#define HUF_4X1_RELOAD_STREAM(_stream) \ + do { \ + int const ctz = ZSTD_countTrailingZeros64(bits[(_stream)]); \ + int const nbBits = ctz & 7; \ + int const nbBytes = ctz >> 3; \ + op[(_stream)] += 5; \ + ip[(_stream)] -= nbBytes; \ + bits[(_stream)] = MEM_read64(ip[(_stream)]) | 1; \ + bits[(_stream)] <<= nbBits; \ + } while (0) + + /* Manually unroll the loop because compilers don't consistently + * unroll the inner loops, which destroys performance. + */ + do { + /* Decode 5 symbols in each of the 4 streams */ + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 0); + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 1); + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 2); + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 3); + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 4); + + /* Reload each of the 4 the bitstreams */ + HUF_4X_FOR_EACH_STREAM(HUF_4X1_RELOAD_STREAM); + } while (op[3] < olimit); + +#undef HUF_4X1_DECODE_SYMBOL +#undef HUF_4X1_RELOAD_STREAM + } + +_out: + + /* Save the final values of each of the state variables back to args. */ + ZSTD_memcpy(&args->bits, &bits, sizeof(bits)); + ZSTD_memcpy((void*)(&args->ip), &ip, sizeof(ip)); + ZSTD_memcpy(&args->op, &op, sizeof(op)); +} + +/** + * @returns @p dstSize on success (>= 6) + * 0 if the fallback implementation should be used + * An error if an error occurred + */ +static HUF_FAST_BMI2_ATTRS +size_t +HUF_decompress4X1_usingDTable_internal_fast( + void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + const HUF_DTable* DTable, + HUF_DecompressFastLoopFn loopFn) +{ + void const* dt = DTable + 1; + BYTE const* const ilowest = (BYTE const*)cSrc; + BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize); + HUF_DecompressFastArgs args; + { size_t const ret = HUF_DecompressFastArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable); + FORWARD_IF_ERROR(ret, "Failed to init fast loop args"); + if (ret == 0) + return 0; + } + + assert(args.ip[0] >= args.ilowest); + loopFn(&args); + + /* Our loop guarantees that ip[] >= ilowest and that we haven't + * overwritten any op[]. + */ + assert(args.ip[0] >= ilowest); + assert(args.ip[0] >= ilowest); + assert(args.ip[1] >= ilowest); + assert(args.ip[2] >= ilowest); + assert(args.ip[3] >= ilowest); + assert(args.op[3] <= oend); + + assert(ilowest == args.ilowest); + assert(ilowest + 6 == args.iend[0]); + (void)ilowest; + + /* finish bit streams one by one. */ + { size_t const segmentSize = (dstSize+3) / 4; + BYTE* segmentEnd = (BYTE*)dst; + int i; + for (i = 0; i < 4; ++i) { + BIT_DStream_t bit; + if (segmentSize <= (size_t)(oend - segmentEnd)) + segmentEnd += segmentSize; + else + segmentEnd = oend; + FORWARD_IF_ERROR(HUF_initRemainingDStream(&bit, &args, i, segmentEnd), "corruption"); + /* Decompress and validate that we've produced exactly the expected length. */ + args.op[i] += HUF_decodeStreamX1(args.op[i], &bit, segmentEnd, (HUF_DEltX1 const*)dt, HUF_DECODER_FAST_TABLELOG); + if (args.op[i] != segmentEnd) return ERROR(corruption_detected); + } + } + + /* decoded size */ + assert(dstSize != 0); + return dstSize; +} + +HUF_DGEN(HUF_decompress1X1_usingDTable_internal) + +static size_t HUF_decompress4X1_usingDTable_internal(void* dst, size_t dstSize, void const* cSrc, + size_t cSrcSize, HUF_DTable const* DTable, int flags) +{ + HUF_DecompressUsingDTableFn fallbackFn = HUF_decompress4X1_usingDTable_internal_default; + HUF_DecompressFastLoopFn loopFn = HUF_decompress4X1_usingDTable_internal_fast_c_loop; + +#if DYNAMIC_BMI2 + if (flags & HUF_flags_bmi2) { + fallbackFn = HUF_decompress4X1_usingDTable_internal_bmi2; +# if ZSTD_ENABLE_ASM_X86_64_BMI2 + if (!(flags & HUF_flags_disableAsm)) { + loopFn = HUF_decompress4X1_usingDTable_internal_fast_asm_loop; + } +# endif + } else { + return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable); + } +#endif + +#if ZSTD_ENABLE_ASM_X86_64_BMI2 && defined(__BMI2__) + if (!(flags & HUF_flags_disableAsm)) { + loopFn = HUF_decompress4X1_usingDTable_internal_fast_asm_loop; + } +#endif + + if (HUF_ENABLE_FAST_DECODE && !(flags & HUF_flags_disableFast)) { + size_t const ret = HUF_decompress4X1_usingDTable_internal_fast(dst, dstSize, cSrc, cSrcSize, DTable, loopFn); + if (ret != 0) + return ret; + } + return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable); +} + +static size_t HUF_decompress4X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + void* workSpace, size_t wkspSize, int flags) +{ + const BYTE* ip = (const BYTE*) cSrc; + + size_t const hSize = HUF_readDTableX1_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize, flags); + if (HUF_isError(hSize)) return hSize; + if (hSize >= cSrcSize) return ERROR(srcSize_wrong); + ip += hSize; cSrcSize -= hSize; + + return HUF_decompress4X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags); +} + +#endif /* HUF_FORCE_DECOMPRESS_X2 */ + + +#ifndef HUF_FORCE_DECOMPRESS_X1 + +/* *************************/ +/* double-symbols decoding */ +/* *************************/ + +typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX2; /* double-symbols decoding */ +typedef struct { BYTE symbol; } sortedSymbol_t; +typedef U32 rankValCol_t[HUF_TABLELOG_MAX + 1]; +typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX]; + +/** + * Constructs a HUF_DEltX2 in a U32. + */ +static U32 HUF_buildDEltX2U32(U32 symbol, U32 nbBits, U32 baseSeq, int level) +{ + U32 seq; + DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, sequence) == 0); + DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, nbBits) == 2); + DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, length) == 3); + DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U32)); + if (MEM_isLittleEndian()) { + seq = level == 1 ? symbol : (baseSeq + (symbol << 8)); + return seq + (nbBits << 16) + ((U32)level << 24); + } else { + seq = level == 1 ? (symbol << 8) : ((baseSeq << 8) + symbol); + return (seq << 16) + (nbBits << 8) + (U32)level; + } +} + +/** + * Constructs a HUF_DEltX2. + */ +static HUF_DEltX2 HUF_buildDEltX2(U32 symbol, U32 nbBits, U32 baseSeq, int level) +{ + HUF_DEltX2 DElt; + U32 const val = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level); + DEBUG_STATIC_ASSERT(sizeof(DElt) == sizeof(val)); + ZSTD_memcpy(&DElt, &val, sizeof(val)); + return DElt; +} + +/** + * Constructs 2 HUF_DEltX2s and packs them into a U64. + */ +static U64 HUF_buildDEltX2U64(U32 symbol, U32 nbBits, U16 baseSeq, int level) +{ + U32 DElt = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level); + return (U64)DElt + ((U64)DElt << 32); +} + +/** + * Fills the DTable rank with all the symbols from [begin, end) that are each + * nbBits long. + * + * @param DTableRank The start of the rank in the DTable. + * @param begin The first symbol to fill (inclusive). + * @param end The last symbol to fill (exclusive). + * @param nbBits Each symbol is nbBits long. + * @param tableLog The table log. + * @param baseSeq If level == 1 { 0 } else { the first level symbol } + * @param level The level in the table. Must be 1 or 2. + */ +static void HUF_fillDTableX2ForWeight( + HUF_DEltX2* DTableRank, + sortedSymbol_t const* begin, sortedSymbol_t const* end, + U32 nbBits, U32 tableLog, + U16 baseSeq, int const level) +{ + U32 const length = 1U << ((tableLog - nbBits) & 0x1F /* quiet static-analyzer */); + const sortedSymbol_t* ptr; + assert(level >= 1 && level <= 2); + switch (length) { + case 1: + for (ptr = begin; ptr != end; ++ptr) { + HUF_DEltX2 const DElt = HUF_buildDEltX2(ptr->symbol, nbBits, baseSeq, level); + *DTableRank++ = DElt; + } + break; + case 2: + for (ptr = begin; ptr != end; ++ptr) { + HUF_DEltX2 const DElt = HUF_buildDEltX2(ptr->symbol, nbBits, baseSeq, level); + DTableRank[0] = DElt; + DTableRank[1] = DElt; + DTableRank += 2; + } + break; + case 4: + for (ptr = begin; ptr != end; ++ptr) { + U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level); + ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2)); + DTableRank += 4; + } + break; + case 8: + for (ptr = begin; ptr != end; ++ptr) { + U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level); + ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTableRank + 4, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTableRank + 6, &DEltX2, sizeof(DEltX2)); + DTableRank += 8; + } + break; + default: + for (ptr = begin; ptr != end; ++ptr) { + U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level); + HUF_DEltX2* const DTableRankEnd = DTableRank + length; + for (; DTableRank != DTableRankEnd; DTableRank += 8) { + ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTableRank + 4, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTableRank + 6, &DEltX2, sizeof(DEltX2)); + } + } + break; + } +} + +/* HUF_fillDTableX2Level2() : + * `rankValOrigin` must be a table of at least (HUF_TABLELOG_MAX + 1) U32 */ +static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 targetLog, const U32 consumedBits, + const U32* rankVal, const int minWeight, const int maxWeight1, + const sortedSymbol_t* sortedSymbols, U32 const* rankStart, + U32 nbBitsBaseline, U16 baseSeq) +{ + /* Fill skipped values (all positions up to rankVal[minWeight]). + * These are positions only get a single symbol because the combined weight + * is too large. + */ + if (minWeight>1) { + U32 const length = 1U << ((targetLog - consumedBits) & 0x1F /* quiet static-analyzer */); + U64 const DEltX2 = HUF_buildDEltX2U64(baseSeq, consumedBits, /* baseSeq */ 0, /* level */ 1); + int const skipSize = rankVal[minWeight]; + assert(length > 1); + assert((U32)skipSize < length); + switch (length) { + case 2: + assert(skipSize == 1); + ZSTD_memcpy(DTable, &DEltX2, sizeof(DEltX2)); + break; + case 4: + assert(skipSize <= 4); + ZSTD_memcpy(DTable + 0, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTable + 2, &DEltX2, sizeof(DEltX2)); + break; + default: + { + int i; + for (i = 0; i < skipSize; i += 8) { + ZSTD_memcpy(DTable + i + 0, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTable + i + 2, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTable + i + 4, &DEltX2, sizeof(DEltX2)); + ZSTD_memcpy(DTable + i + 6, &DEltX2, sizeof(DEltX2)); + } + } + } + } + + /* Fill each of the second level symbols by weight. */ + { + int w; + for (w = minWeight; w < maxWeight1; ++w) { + int const begin = rankStart[w]; + int const end = rankStart[w+1]; + U32 const nbBits = nbBitsBaseline - w; + U32 const totalBits = nbBits + consumedBits; + HUF_fillDTableX2ForWeight( + DTable + rankVal[w], + sortedSymbols + begin, sortedSymbols + end, + totalBits, targetLog, + baseSeq, /* level */ 2); + } + } +} + +static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog, + const sortedSymbol_t* sortedList, + const U32* rankStart, rankValCol_t* rankValOrigin, const U32 maxWeight, + const U32 nbBitsBaseline) +{ + U32* const rankVal = rankValOrigin[0]; + const int scaleLog = nbBitsBaseline - targetLog; /* note : targetLog >= srcLog, hence scaleLog <= 1 */ + const U32 minBits = nbBitsBaseline - maxWeight; + int w; + int const wEnd = (int)maxWeight + 1; + + /* Fill DTable in order of weight. */ + for (w = 1; w < wEnd; ++w) { + int const begin = (int)rankStart[w]; + int const end = (int)rankStart[w+1]; + U32 const nbBits = nbBitsBaseline - w; + + if (targetLog-nbBits >= minBits) { + /* Enough room for a second symbol. */ + int start = rankVal[w]; + U32 const length = 1U << ((targetLog - nbBits) & 0x1F /* quiet static-analyzer */); + int minWeight = nbBits + scaleLog; + int s; + if (minWeight < 1) minWeight = 1; + /* Fill the DTable for every symbol of weight w. + * These symbols get at least 1 second symbol. + */ + for (s = begin; s != end; ++s) { + HUF_fillDTableX2Level2( + DTable + start, targetLog, nbBits, + rankValOrigin[nbBits], minWeight, wEnd, + sortedList, rankStart, + nbBitsBaseline, sortedList[s].symbol); + start += length; + } + } else { + /* Only a single symbol. */ + HUF_fillDTableX2ForWeight( + DTable + rankVal[w], + sortedList + begin, sortedList + end, + nbBits, targetLog, + /* baseSeq */ 0, /* level */ 1); + } + } +} + +typedef struct { + rankValCol_t rankVal[HUF_TABLELOG_MAX]; + U32 rankStats[HUF_TABLELOG_MAX + 1]; + U32 rankStart0[HUF_TABLELOG_MAX + 3]; + sortedSymbol_t sortedSymbol[HUF_SYMBOLVALUE_MAX + 1]; + BYTE weightList[HUF_SYMBOLVALUE_MAX + 1]; + U32 calleeWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32]; +} HUF_ReadDTableX2_Workspace; + +size_t HUF_readDTableX2_wksp(HUF_DTable* DTable, + const void* src, size_t srcSize, + void* workSpace, size_t wkspSize, int flags) +{ + U32 tableLog, maxW, nbSymbols; + DTableDesc dtd = HUF_getDTableDesc(DTable); + U32 maxTableLog = dtd.maxTableLog; + size_t iSize; + void* dtPtr = DTable+1; /* force compiler to avoid strict-aliasing */ + HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr; + U32 *rankStart; + + HUF_ReadDTableX2_Workspace* const wksp = (HUF_ReadDTableX2_Workspace*)workSpace; + + if (sizeof(*wksp) > wkspSize) return ERROR(GENERIC); + + rankStart = wksp->rankStart0 + 1; + ZSTD_memset(wksp->rankStats, 0, sizeof(wksp->rankStats)); + ZSTD_memset(wksp->rankStart0, 0, sizeof(wksp->rankStart0)); + + DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(HUF_DTable)); /* if compiler fails here, assertion is wrong */ + if (maxTableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge); + /* ZSTD_memset(weightList, 0, sizeof(weightList)); */ /* is not necessary, even though some analyzer complain ... */ + + iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->calleeWksp, sizeof(wksp->calleeWksp), flags); + if (HUF_isError(iSize)) return iSize; + + /* check result */ + if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge); /* DTable can't fit code depth */ + if (tableLog <= HUF_DECODER_FAST_TABLELOG && maxTableLog > HUF_DECODER_FAST_TABLELOG) maxTableLog = HUF_DECODER_FAST_TABLELOG; + + /* find maxWeight */ + for (maxW = tableLog; wksp->rankStats[maxW]==0; maxW--) {} /* necessarily finds a solution before 0 */ + + /* Get start index of each weight */ + { U32 w, nextRankStart = 0; + for (w=1; wrankStats[w]; + rankStart[w] = curr; + } + rankStart[0] = nextRankStart; /* put all 0w symbols at the end of sorted list*/ + rankStart[maxW+1] = nextRankStart; + } + + /* sort symbols by weight */ + { U32 s; + for (s=0; sweightList[s]; + U32 const r = rankStart[w]++; + wksp->sortedSymbol[r].symbol = (BYTE)s; + } + rankStart[0] = 0; /* forget 0w symbols; this is beginning of weight(1) */ + } + + /* Build rankVal */ + { U32* const rankVal0 = wksp->rankVal[0]; + { int const rescale = (maxTableLog-tableLog) - 1; /* tableLog <= maxTableLog */ + U32 nextRankVal = 0; + U32 w; + for (w=1; wrankStats[w] << (w+rescale); + rankVal0[w] = curr; + } } + { U32 const minBits = tableLog+1 - maxW; + U32 consumed; + for (consumed = minBits; consumed < maxTableLog - minBits + 1; consumed++) { + U32* const rankValPtr = wksp->rankVal[consumed]; + U32 w; + for (w = 1; w < maxW+1; w++) { + rankValPtr[w] = rankVal0[w] >> consumed; + } } } } + + HUF_fillDTableX2(dt, maxTableLog, + wksp->sortedSymbol, + wksp->rankStart0, wksp->rankVal, maxW, + tableLog+1); + + dtd.tableLog = (BYTE)maxTableLog; + dtd.tableType = 1; + ZSTD_memcpy(DTable, &dtd, sizeof(dtd)); + return iSize; +} + + +FORCE_INLINE_TEMPLATE U32 +HUF_decodeSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog) +{ + size_t const val = BIT_lookBitsFast(DStream, dtLog); /* note : dtLog >= 1 */ + ZSTD_memcpy(op, &dt[val].sequence, 2); + BIT_skipBits(DStream, dt[val].nbBits); + return dt[val].length; +} + +FORCE_INLINE_TEMPLATE U32 +HUF_decodeLastSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog) +{ + size_t const val = BIT_lookBitsFast(DStream, dtLog); /* note : dtLog >= 1 */ + ZSTD_memcpy(op, &dt[val].sequence, 1); + if (dt[val].length==1) { + BIT_skipBits(DStream, dt[val].nbBits); + } else { + if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8)) { + BIT_skipBits(DStream, dt[val].nbBits); + if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8)) + /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */ + DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8); + } + } + return 1; +} + +#define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \ + do { ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog); } while (0) + +#define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \ + do { \ + if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \ + ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog); \ + } while (0) + +#define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \ + do { \ + if (MEM_64bits()) \ + ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog); \ + } while (0) + +HINT_INLINE size_t +HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, + const HUF_DEltX2* const dt, const U32 dtLog) +{ + BYTE* const pStart = p; + + /* up to 8 symbols at a time */ + if ((size_t)(pEnd - p) >= sizeof(bitDPtr->bitContainer)) { + if (dtLog <= 11 && MEM_64bits()) { + /* up to 10 symbols at a time */ + while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-9)) { + HUF_DECODE_SYMBOLX2_0(p, bitDPtr); + HUF_DECODE_SYMBOLX2_0(p, bitDPtr); + HUF_DECODE_SYMBOLX2_0(p, bitDPtr); + HUF_DECODE_SYMBOLX2_0(p, bitDPtr); + HUF_DECODE_SYMBOLX2_0(p, bitDPtr); + } + } else { + /* up to 8 symbols at a time */ + while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-(sizeof(bitDPtr->bitContainer)-1))) { + HUF_DECODE_SYMBOLX2_2(p, bitDPtr); + HUF_DECODE_SYMBOLX2_1(p, bitDPtr); + HUF_DECODE_SYMBOLX2_2(p, bitDPtr); + HUF_DECODE_SYMBOLX2_0(p, bitDPtr); + } + } + } else { + BIT_reloadDStream(bitDPtr); + } + + /* closer to end : up to 2 symbols at a time */ + if ((size_t)(pEnd - p) >= 2) { + while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p <= pEnd-2)) + HUF_DECODE_SYMBOLX2_0(p, bitDPtr); + + while (p <= pEnd-2) + HUF_DECODE_SYMBOLX2_0(p, bitDPtr); /* no need to reload : reached the end of DStream */ + } + + if (p < pEnd) + p += HUF_decodeLastSymbolX2(p, bitDPtr, dt, dtLog); + + return p-pStart; +} + +FORCE_INLINE_TEMPLATE size_t +HUF_decompress1X2_usingDTable_internal_body( + void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + const HUF_DTable* DTable) +{ + BIT_DStream_t bitD; + + /* Init */ + CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) ); + + /* decode */ + { BYTE* const ostart = (BYTE*) dst; + BYTE* const oend = ZSTD_maybeNullPtrAdd(ostart, dstSize); + const void* const dtPtr = DTable+1; /* force compiler to not use strict-aliasing */ + const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr; + DTableDesc const dtd = HUF_getDTableDesc(DTable); + HUF_decodeStreamX2(ostart, &bitD, oend, dt, dtd.tableLog); + } + + /* check */ + if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected); + + /* decoded size */ + return dstSize; +} + +/* HUF_decompress4X2_usingDTable_internal_body(): + * Conditions: + * @dstSize >= 6 + */ +FORCE_INLINE_TEMPLATE size_t +HUF_decompress4X2_usingDTable_internal_body( + void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + const HUF_DTable* DTable) +{ + if (cSrcSize < 10) return ERROR(corruption_detected); /* strict minimum : jump table + 1 byte per stream */ + if (dstSize < 6) return ERROR(corruption_detected); /* stream 4-split doesn't work */ + + { const BYTE* const istart = (const BYTE*) cSrc; + BYTE* const ostart = (BYTE*) dst; + BYTE* const oend = ostart + dstSize; + BYTE* const olimit = oend - (sizeof(size_t)-1); + const void* const dtPtr = DTable+1; + const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr; + + /* Init */ + BIT_DStream_t bitD1; + BIT_DStream_t bitD2; + BIT_DStream_t bitD3; + BIT_DStream_t bitD4; + size_t const length1 = MEM_readLE16(istart); + size_t const length2 = MEM_readLE16(istart+2); + size_t const length3 = MEM_readLE16(istart+4); + size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6); + const BYTE* const istart1 = istart + 6; /* jumpTable */ + const BYTE* const istart2 = istart1 + length1; + const BYTE* const istart3 = istart2 + length2; + const BYTE* const istart4 = istart3 + length3; + size_t const segmentSize = (dstSize+3) / 4; + BYTE* const opStart2 = ostart + segmentSize; + BYTE* const opStart3 = opStart2 + segmentSize; + BYTE* const opStart4 = opStart3 + segmentSize; + BYTE* op1 = ostart; + BYTE* op2 = opStart2; + BYTE* op3 = opStart3; + BYTE* op4 = opStart4; + U32 endSignal = 1; + DTableDesc const dtd = HUF_getDTableDesc(DTable); + U32 const dtLog = dtd.tableLog; + + if (length4 > cSrcSize) return ERROR(corruption_detected); /* overflow */ + if (opStart4 > oend) return ERROR(corruption_detected); /* overflow */ + assert(dstSize >= 6 /* validated above */); + CHECK_F( BIT_initDStream(&bitD1, istart1, length1) ); + CHECK_F( BIT_initDStream(&bitD2, istart2, length2) ); + CHECK_F( BIT_initDStream(&bitD3, istart3, length3) ); + CHECK_F( BIT_initDStream(&bitD4, istart4, length4) ); + + /* 16-32 symbols per loop (4-8 symbols per stream) */ + if ((size_t)(oend - op4) >= sizeof(size_t)) { + for ( ; (endSignal) & (op4 < olimit); ) { +#if defined(__clang__) && (defined(__x86_64__) || defined(__i386__)) + HUF_DECODE_SYMBOLX2_2(op1, &bitD1); + HUF_DECODE_SYMBOLX2_1(op1, &bitD1); + HUF_DECODE_SYMBOLX2_2(op1, &bitD1); + HUF_DECODE_SYMBOLX2_0(op1, &bitD1); + HUF_DECODE_SYMBOLX2_2(op2, &bitD2); + HUF_DECODE_SYMBOLX2_1(op2, &bitD2); + HUF_DECODE_SYMBOLX2_2(op2, &bitD2); + HUF_DECODE_SYMBOLX2_0(op2, &bitD2); + endSignal &= BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished; + endSignal &= BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished; + HUF_DECODE_SYMBOLX2_2(op3, &bitD3); + HUF_DECODE_SYMBOLX2_1(op3, &bitD3); + HUF_DECODE_SYMBOLX2_2(op3, &bitD3); + HUF_DECODE_SYMBOLX2_0(op3, &bitD3); + HUF_DECODE_SYMBOLX2_2(op4, &bitD4); + HUF_DECODE_SYMBOLX2_1(op4, &bitD4); + HUF_DECODE_SYMBOLX2_2(op4, &bitD4); + HUF_DECODE_SYMBOLX2_0(op4, &bitD4); + endSignal &= BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished; + endSignal &= BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished; +#else + HUF_DECODE_SYMBOLX2_2(op1, &bitD1); + HUF_DECODE_SYMBOLX2_2(op2, &bitD2); + HUF_DECODE_SYMBOLX2_2(op3, &bitD3); + HUF_DECODE_SYMBOLX2_2(op4, &bitD4); + HUF_DECODE_SYMBOLX2_1(op1, &bitD1); + HUF_DECODE_SYMBOLX2_1(op2, &bitD2); + HUF_DECODE_SYMBOLX2_1(op3, &bitD3); + HUF_DECODE_SYMBOLX2_1(op4, &bitD4); + HUF_DECODE_SYMBOLX2_2(op1, &bitD1); + HUF_DECODE_SYMBOLX2_2(op2, &bitD2); + HUF_DECODE_SYMBOLX2_2(op3, &bitD3); + HUF_DECODE_SYMBOLX2_2(op4, &bitD4); + HUF_DECODE_SYMBOLX2_0(op1, &bitD1); + HUF_DECODE_SYMBOLX2_0(op2, &bitD2); + HUF_DECODE_SYMBOLX2_0(op3, &bitD3); + HUF_DECODE_SYMBOLX2_0(op4, &bitD4); + endSignal = (U32)LIKELY((U32) + (BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished) + & (BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished) + & (BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished) + & (BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished)); +#endif + } + } + + /* check corruption */ + if (op1 > opStart2) return ERROR(corruption_detected); + if (op2 > opStart3) return ERROR(corruption_detected); + if (op3 > opStart4) return ERROR(corruption_detected); + /* note : op4 already verified within main loop */ + + /* finish bitStreams one by one */ + HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog); + HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog); + HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog); + HUF_decodeStreamX2(op4, &bitD4, oend, dt, dtLog); + + /* check */ + { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4); + if (!endCheck) return ERROR(corruption_detected); } + + /* decoded size */ + return dstSize; + } +} + +#if HUF_NEED_BMI2_FUNCTION +static BMI2_TARGET_ATTRIBUTE +size_t HUF_decompress4X2_usingDTable_internal_bmi2(void* dst, size_t dstSize, void const* cSrc, + size_t cSrcSize, HUF_DTable const* DTable) { + return HUF_decompress4X2_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable); +} +#endif + +static +size_t HUF_decompress4X2_usingDTable_internal_default(void* dst, size_t dstSize, void const* cSrc, + size_t cSrcSize, HUF_DTable const* DTable) { + return HUF_decompress4X2_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable); +} + +#if ZSTD_ENABLE_ASM_X86_64_BMI2 + +HUF_ASM_DECL void HUF_decompress4X2_usingDTable_internal_fast_asm_loop(HUF_DecompressFastArgs* args) ZSTDLIB_HIDDEN; + +#endif + +static HUF_FAST_BMI2_ATTRS +void HUF_decompress4X2_usingDTable_internal_fast_c_loop(HUF_DecompressFastArgs* args) +{ + U64 bits[4]; + BYTE const* ip[4]; + BYTE* op[4]; + BYTE* oend[4]; + HUF_DEltX2 const* const dtable = (HUF_DEltX2 const*)args->dt; + BYTE const* const ilowest = args->ilowest; + + /* Copy the arguments to local registers. */ + ZSTD_memcpy(&bits, &args->bits, sizeof(bits)); + ZSTD_memcpy((void*)(&ip), &args->ip, sizeof(ip)); + ZSTD_memcpy(&op, &args->op, sizeof(op)); + + oend[0] = op[1]; + oend[1] = op[2]; + oend[2] = op[3]; + oend[3] = args->oend; + + assert(MEM_isLittleEndian()); + assert(!MEM_32bits()); + + for (;;) { + BYTE* olimit; + int stream; + + /* Assert loop preconditions */ +#ifndef NDEBUG + for (stream = 0; stream < 4; ++stream) { + assert(op[stream] <= oend[stream]); + assert(ip[stream] >= ilowest); + } +#endif + /* Compute olimit */ + { + /* Each loop does 5 table lookups for each of the 4 streams. + * Each table lookup consumes up to 11 bits of input, and produces + * up to 2 bytes of output. + */ + /* We can consume up to 7 bytes of input per iteration per stream. + * We also know that each input pointer is >= ip[0]. So we can run + * iters loops before running out of input. + */ + size_t iters = (size_t)(ip[0] - ilowest) / 7; + /* Each iteration can produce up to 10 bytes of output per stream. + * Each output stream my advance at different rates. So take the + * minimum number of safe iterations among all the output streams. + */ + for (stream = 0; stream < 4; ++stream) { + size_t const oiters = (size_t)(oend[stream] - op[stream]) / 10; + iters = MIN(iters, oiters); + } + + /* Each iteration produces at least 5 output symbols. So until + * op[3] crosses olimit, we know we haven't executed iters + * iterations yet. This saves us maintaining an iters counter, + * at the expense of computing the remaining # of iterations + * more frequently. + */ + olimit = op[3] + (iters * 5); + + /* Exit the fast decoding loop once we reach the end. */ + if (op[3] == olimit) + break; + + /* Exit the decoding loop if any input pointer has crossed the + * previous one. This indicates corruption, and a precondition + * to our loop is that ip[i] >= ip[0]. + */ + for (stream = 1; stream < 4; ++stream) { + if (ip[stream] < ip[stream - 1]) + goto _out; + } + } + +#ifndef NDEBUG + for (stream = 1; stream < 4; ++stream) { + assert(ip[stream] >= ip[stream - 1]); + } +#endif + +#define HUF_4X2_DECODE_SYMBOL(_stream, _decode3) \ + do { \ + if ((_decode3) || (_stream) != 3) { \ + int const index = (int)(bits[(_stream)] >> 53); \ + HUF_DEltX2 const entry = dtable[index]; \ + MEM_write16(op[(_stream)], entry.sequence); \ + bits[(_stream)] <<= (entry.nbBits) & 0x3F; \ + op[(_stream)] += (entry.length); \ + } \ + } while (0) + +#define HUF_4X2_RELOAD_STREAM(_stream) \ + do { \ + HUF_4X2_DECODE_SYMBOL(3, 1); \ + { \ + int const ctz = ZSTD_countTrailingZeros64(bits[(_stream)]); \ + int const nbBits = ctz & 7; \ + int const nbBytes = ctz >> 3; \ + ip[(_stream)] -= nbBytes; \ + bits[(_stream)] = MEM_read64(ip[(_stream)]) | 1; \ + bits[(_stream)] <<= nbBits; \ + } \ + } while (0) + + /* Manually unroll the loop because compilers don't consistently + * unroll the inner loops, which destroys performance. + */ + do { + /* Decode 5 symbols from each of the first 3 streams. + * The final stream will be decoded during the reload phase + * to reduce register pressure. + */ + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0); + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0); + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0); + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0); + HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0); + + /* Decode one symbol from the final stream */ + HUF_4X2_DECODE_SYMBOL(3, 1); + + /* Decode 4 symbols from the final stream & reload bitstreams. + * The final stream is reloaded last, meaning that all 5 symbols + * are decoded from the final stream before it is reloaded. + */ + HUF_4X_FOR_EACH_STREAM(HUF_4X2_RELOAD_STREAM); + } while (op[3] < olimit); + } + +#undef HUF_4X2_DECODE_SYMBOL +#undef HUF_4X2_RELOAD_STREAM + +_out: + + /* Save the final values of each of the state variables back to args. */ + ZSTD_memcpy(&args->bits, &bits, sizeof(bits)); + ZSTD_memcpy((void*)(&args->ip), &ip, sizeof(ip)); + ZSTD_memcpy(&args->op, &op, sizeof(op)); +} + + +static HUF_FAST_BMI2_ATTRS size_t +HUF_decompress4X2_usingDTable_internal_fast( + void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + const HUF_DTable* DTable, + HUF_DecompressFastLoopFn loopFn) { + void const* dt = DTable + 1; + const BYTE* const ilowest = (const BYTE*)cSrc; + BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize); + HUF_DecompressFastArgs args; + { + size_t const ret = HUF_DecompressFastArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable); + FORWARD_IF_ERROR(ret, "Failed to init asm args"); + if (ret == 0) + return 0; + } + + assert(args.ip[0] >= args.ilowest); + loopFn(&args); + + /* note : op4 already verified within main loop */ + assert(args.ip[0] >= ilowest); + assert(args.ip[1] >= ilowest); + assert(args.ip[2] >= ilowest); + assert(args.ip[3] >= ilowest); + assert(args.op[3] <= oend); + + assert(ilowest == args.ilowest); + assert(ilowest + 6 == args.iend[0]); + (void)ilowest; + + /* finish bitStreams one by one */ + { + size_t const segmentSize = (dstSize+3) / 4; + BYTE* segmentEnd = (BYTE*)dst; + int i; + for (i = 0; i < 4; ++i) { + BIT_DStream_t bit; + if (segmentSize <= (size_t)(oend - segmentEnd)) + segmentEnd += segmentSize; + else + segmentEnd = oend; + FORWARD_IF_ERROR(HUF_initRemainingDStream(&bit, &args, i, segmentEnd), "corruption"); + args.op[i] += HUF_decodeStreamX2(args.op[i], &bit, segmentEnd, (HUF_DEltX2 const*)dt, HUF_DECODER_FAST_TABLELOG); + if (args.op[i] != segmentEnd) + return ERROR(corruption_detected); + } + } + + /* decoded size */ + return dstSize; +} + +static size_t HUF_decompress4X2_usingDTable_internal(void* dst, size_t dstSize, void const* cSrc, + size_t cSrcSize, HUF_DTable const* DTable, int flags) +{ + HUF_DecompressUsingDTableFn fallbackFn = HUF_decompress4X2_usingDTable_internal_default; + HUF_DecompressFastLoopFn loopFn = HUF_decompress4X2_usingDTable_internal_fast_c_loop; + +#if DYNAMIC_BMI2 + if (flags & HUF_flags_bmi2) { + fallbackFn = HUF_decompress4X2_usingDTable_internal_bmi2; +# if ZSTD_ENABLE_ASM_X86_64_BMI2 + if (!(flags & HUF_flags_disableAsm)) { + loopFn = HUF_decompress4X2_usingDTable_internal_fast_asm_loop; + } +# endif + } else { + return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable); + } +#endif + +#if ZSTD_ENABLE_ASM_X86_64_BMI2 && defined(__BMI2__) + if (!(flags & HUF_flags_disableAsm)) { + loopFn = HUF_decompress4X2_usingDTable_internal_fast_asm_loop; + } +#endif + + if (HUF_ENABLE_FAST_DECODE && !(flags & HUF_flags_disableFast)) { + size_t const ret = HUF_decompress4X2_usingDTable_internal_fast(dst, dstSize, cSrc, cSrcSize, DTable, loopFn); + if (ret != 0) + return ret; + } + return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable); +} + +HUF_DGEN(HUF_decompress1X2_usingDTable_internal) + +size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + void* workSpace, size_t wkspSize, int flags) +{ + const BYTE* ip = (const BYTE*) cSrc; + + size_t const hSize = HUF_readDTableX2_wksp(DCtx, cSrc, cSrcSize, + workSpace, wkspSize, flags); + if (HUF_isError(hSize)) return hSize; + if (hSize >= cSrcSize) return ERROR(srcSize_wrong); + ip += hSize; cSrcSize -= hSize; + + return HUF_decompress1X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, flags); +} + +static size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + void* workSpace, size_t wkspSize, int flags) +{ + const BYTE* ip = (const BYTE*) cSrc; + + size_t hSize = HUF_readDTableX2_wksp(dctx, cSrc, cSrcSize, + workSpace, wkspSize, flags); + if (HUF_isError(hSize)) return hSize; + if (hSize >= cSrcSize) return ERROR(srcSize_wrong); + ip += hSize; cSrcSize -= hSize; + + return HUF_decompress4X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags); +} + +#endif /* HUF_FORCE_DECOMPRESS_X1 */ + + +/* ***********************************/ +/* Universal decompression selectors */ +/* ***********************************/ + + +#if !defined(HUF_FORCE_DECOMPRESS_X1) && !defined(HUF_FORCE_DECOMPRESS_X2) +typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t; +static const algo_time_t algoTime[16 /* Quantization */][2 /* single, double */] = +{ + /* single, double, quad */ + {{0,0}, {1,1}}, /* Q==0 : impossible */ + {{0,0}, {1,1}}, /* Q==1 : impossible */ + {{ 150,216}, { 381,119}}, /* Q == 2 : 12-18% */ + {{ 170,205}, { 514,112}}, /* Q == 3 : 18-25% */ + {{ 177,199}, { 539,110}}, /* Q == 4 : 25-32% */ + {{ 197,194}, { 644,107}}, /* Q == 5 : 32-38% */ + {{ 221,192}, { 735,107}}, /* Q == 6 : 38-44% */ + {{ 256,189}, { 881,106}}, /* Q == 7 : 44-50% */ + {{ 359,188}, {1167,109}}, /* Q == 8 : 50-56% */ + {{ 582,187}, {1570,114}}, /* Q == 9 : 56-62% */ + {{ 688,187}, {1712,122}}, /* Q ==10 : 62-69% */ + {{ 825,186}, {1965,136}}, /* Q ==11 : 69-75% */ + {{ 976,185}, {2131,150}}, /* Q ==12 : 75-81% */ + {{1180,186}, {2070,175}}, /* Q ==13 : 81-87% */ + {{1377,185}, {1731,202}}, /* Q ==14 : 87-93% */ + {{1412,185}, {1695,202}}, /* Q ==15 : 93-99% */ +}; +#endif + +/** HUF_selectDecoder() : + * Tells which decoder is likely to decode faster, + * based on a set of pre-computed metrics. + * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 . + * Assumption : 0 < dstSize <= 128 KB */ +U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize) +{ + assert(dstSize > 0); + assert(dstSize <= 128*1024); +#if defined(HUF_FORCE_DECOMPRESS_X1) + (void)dstSize; + (void)cSrcSize; + return 0; +#elif defined(HUF_FORCE_DECOMPRESS_X2) + (void)dstSize; + (void)cSrcSize; + return 1; +#else + /* decoder timing evaluation */ + { U32 const Q = (cSrcSize >= dstSize) ? 15 : (U32)(cSrcSize * 16 / dstSize); /* Q < 16 */ + U32 const D256 = (U32)(dstSize >> 8); + U32 const DTime0 = algoTime[Q][0].tableTime + (algoTime[Q][0].decode256Time * D256); + U32 DTime1 = algoTime[Q][1].tableTime + (algoTime[Q][1].decode256Time * D256); + DTime1 += DTime1 >> 5; /* small advantage to algorithm using less memory, to reduce cache eviction */ + return DTime1 < DTime0; + } +#endif +} + +size_t HUF_decompress1X_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, + const void* cSrc, size_t cSrcSize, + void* workSpace, size_t wkspSize, int flags) +{ + /* validation checks */ + if (dstSize == 0) return ERROR(dstSize_tooSmall); + if (cSrcSize > dstSize) return ERROR(corruption_detected); /* invalid */ + if (cSrcSize == dstSize) { ZSTD_memcpy(dst, cSrc, dstSize); return dstSize; } /* not compressed */ + if (cSrcSize == 1) { ZSTD_memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; } /* RLE */ + + { U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize); +#if defined(HUF_FORCE_DECOMPRESS_X1) + (void)algoNb; + assert(algoNb == 0); + return HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc, + cSrcSize, workSpace, wkspSize, flags); +#elif defined(HUF_FORCE_DECOMPRESS_X2) + (void)algoNb; + assert(algoNb == 1); + return HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc, + cSrcSize, workSpace, wkspSize, flags); +#else + return algoNb ? HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc, + cSrcSize, workSpace, wkspSize, flags): + HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc, + cSrcSize, workSpace, wkspSize, flags); +#endif + } +} + + +size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags) +{ + DTableDesc const dtd = HUF_getDTableDesc(DTable); +#if defined(HUF_FORCE_DECOMPRESS_X1) + (void)dtd; + assert(dtd.tableType == 0); + return HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); +#elif defined(HUF_FORCE_DECOMPRESS_X2) + (void)dtd; + assert(dtd.tableType == 1); + return HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); +#else + return dtd.tableType ? HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags) : + HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); +#endif +} + +#ifndef HUF_FORCE_DECOMPRESS_X2 +size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags) +{ + const BYTE* ip = (const BYTE*) cSrc; + + size_t const hSize = HUF_readDTableX1_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize, flags); + if (HUF_isError(hSize)) return hSize; + if (hSize >= cSrcSize) return ERROR(srcSize_wrong); + ip += hSize; cSrcSize -= hSize; + + return HUF_decompress1X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags); +} +#endif + +size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags) +{ + DTableDesc const dtd = HUF_getDTableDesc(DTable); +#if defined(HUF_FORCE_DECOMPRESS_X1) + (void)dtd; + assert(dtd.tableType == 0); + return HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); +#elif defined(HUF_FORCE_DECOMPRESS_X2) + (void)dtd; + assert(dtd.tableType == 1); + return HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); +#else + return dtd.tableType ? HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags) : + HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); +#endif +} + +size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags) +{ + /* validation checks */ + if (dstSize == 0) return ERROR(dstSize_tooSmall); + if (cSrcSize == 0) return ERROR(corruption_detected); + + { U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize); +#if defined(HUF_FORCE_DECOMPRESS_X1) + (void)algoNb; + assert(algoNb == 0); + return HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); +#elif defined(HUF_FORCE_DECOMPRESS_X2) + (void)algoNb; + assert(algoNb == 1); + return HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); +#else + return algoNb ? HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags) : + HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); +#endif + } +} diff --git a/third_party/zstd/lib/decompress/huf_decompress_amd64.S b/third_party/zstd/lib/decompress/huf_decompress_amd64.S new file mode 100644 index 0000000000..78da291ee3 --- /dev/null +++ b/third_party/zstd/lib/decompress/huf_decompress_amd64.S @@ -0,0 +1,595 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + +#include "../common/portability_macros.h" + +#if defined(__ELF__) && defined(__GNUC__) +/* Stack marking + * ref: https://wiki.gentoo.org/wiki/Hardened/GNU_stack_quickstart + */ +.section .note.GNU-stack,"",%progbits + +#if defined(__aarch64__) +/* Mark that this assembly supports BTI & PAC, because it is empty for aarch64. + * See: https://github.com/facebook/zstd/issues/3841 + * See: https://gcc.godbolt.org/z/sqr5T4ffK + * See: https://lore.kernel.org/linux-arm-kernel/20200429211641.9279-8-broonie@kernel.org/ + * See: https://reviews.llvm.org/D62609 + */ +.pushsection .note.gnu.property, "a" +.p2align 3 +.long 4 /* size of the name - "GNU\0" */ +.long 0x10 /* size of descriptor */ +.long 0x5 /* NT_GNU_PROPERTY_TYPE_0 */ +.asciz "GNU" +.long 0xc0000000 /* pr_type - GNU_PROPERTY_AARCH64_FEATURE_1_AND */ +.long 4 /* pr_datasz - 4 bytes */ +.long 3 /* pr_data - GNU_PROPERTY_AARCH64_FEATURE_1_BTI | GNU_PROPERTY_AARCH64_FEATURE_1_PAC */ +.p2align 3 /* pr_padding - bring everything to 8 byte alignment */ +.popsection +#endif + +#endif + +#if ZSTD_ENABLE_ASM_X86_64_BMI2 + +/* Calling convention: + * + * %rdi contains the first argument: HUF_DecompressAsmArgs*. + * %rbp isn't maintained (no frame pointer). + * %rsp contains the stack pointer that grows down. + * No red-zone is assumed, only addresses >= %rsp are used. + * All register contents are preserved. + * + * TODO: Support Windows calling convention. + */ + +ZSTD_HIDE_ASM_FUNCTION(HUF_decompress4X1_usingDTable_internal_fast_asm_loop) +ZSTD_HIDE_ASM_FUNCTION(HUF_decompress4X2_usingDTable_internal_fast_asm_loop) +ZSTD_HIDE_ASM_FUNCTION(_HUF_decompress4X2_usingDTable_internal_fast_asm_loop) +ZSTD_HIDE_ASM_FUNCTION(_HUF_decompress4X1_usingDTable_internal_fast_asm_loop) +.global HUF_decompress4X1_usingDTable_internal_fast_asm_loop +.global HUF_decompress4X2_usingDTable_internal_fast_asm_loop +.global _HUF_decompress4X1_usingDTable_internal_fast_asm_loop +.global _HUF_decompress4X2_usingDTable_internal_fast_asm_loop +.text + +/* Sets up register mappings for clarity. + * op[], bits[], dtable & ip[0] each get their own register. + * ip[1,2,3] & olimit alias var[]. + * %rax is a scratch register. + */ + +#define op0 rsi +#define op1 rbx +#define op2 rcx +#define op3 rdi + +#define ip0 r8 +#define ip1 r9 +#define ip2 r10 +#define ip3 r11 + +#define bits0 rbp +#define bits1 rdx +#define bits2 r12 +#define bits3 r13 +#define dtable r14 +#define olimit r15 + +/* var[] aliases ip[1,2,3] & olimit + * ip[1,2,3] are saved every iteration. + * olimit is only used in compute_olimit. + */ +#define var0 r15 +#define var1 r9 +#define var2 r10 +#define var3 r11 + +/* 32-bit var registers */ +#define vard0 r15d +#define vard1 r9d +#define vard2 r10d +#define vard3 r11d + +/* Calls X(N) for each stream 0, 1, 2, 3. */ +#define FOR_EACH_STREAM(X) \ + X(0); \ + X(1); \ + X(2); \ + X(3) + +/* Calls X(N, idx) for each stream 0, 1, 2, 3. */ +#define FOR_EACH_STREAM_WITH_INDEX(X, idx) \ + X(0, idx); \ + X(1, idx); \ + X(2, idx); \ + X(3, idx) + +/* Define both _HUF_* & HUF_* symbols because MacOS + * C symbols are prefixed with '_' & Linux symbols aren't. + */ +_HUF_decompress4X1_usingDTable_internal_fast_asm_loop: +HUF_decompress4X1_usingDTable_internal_fast_asm_loop: + ZSTD_CET_ENDBRANCH + /* Save all registers - even if they are callee saved for simplicity. */ + push %rax + push %rbx + push %rcx + push %rdx + push %rbp + push %rsi + push %rdi + push %r8 + push %r9 + push %r10 + push %r11 + push %r12 + push %r13 + push %r14 + push %r15 + + /* Read HUF_DecompressAsmArgs* args from %rax */ + movq %rdi, %rax + movq 0(%rax), %ip0 + movq 8(%rax), %ip1 + movq 16(%rax), %ip2 + movq 24(%rax), %ip3 + movq 32(%rax), %op0 + movq 40(%rax), %op1 + movq 48(%rax), %op2 + movq 56(%rax), %op3 + movq 64(%rax), %bits0 + movq 72(%rax), %bits1 + movq 80(%rax), %bits2 + movq 88(%rax), %bits3 + movq 96(%rax), %dtable + push %rax /* argument */ + push 104(%rax) /* ilowest */ + push 112(%rax) /* oend */ + push %olimit /* olimit space */ + + subq $24, %rsp + +.L_4X1_compute_olimit: + /* Computes how many iterations we can do safely + * %r15, %rax may be clobbered + * rbx, rdx must be saved + * op3 & ip0 mustn't be clobbered + */ + movq %rbx, 0(%rsp) + movq %rdx, 8(%rsp) + + movq 32(%rsp), %rax /* rax = oend */ + subq %op3, %rax /* rax = oend - op3 */ + + /* r15 = (oend - op3) / 5 */ + movabsq $-3689348814741910323, %rdx + mulq %rdx + movq %rdx, %r15 + shrq $2, %r15 + + movq %ip0, %rax /* rax = ip0 */ + movq 40(%rsp), %rdx /* rdx = ilowest */ + subq %rdx, %rax /* rax = ip0 - ilowest */ + movq %rax, %rbx /* rbx = ip0 - ilowest */ + + /* rdx = (ip0 - ilowest) / 7 */ + movabsq $2635249153387078803, %rdx + mulq %rdx + subq %rdx, %rbx + shrq %rbx + addq %rbx, %rdx + shrq $2, %rdx + + /* r15 = min(%rdx, %r15) */ + cmpq %rdx, %r15 + cmova %rdx, %r15 + + /* r15 = r15 * 5 */ + leaq (%r15, %r15, 4), %r15 + + /* olimit = op3 + r15 */ + addq %op3, %olimit + + movq 8(%rsp), %rdx + movq 0(%rsp), %rbx + + /* If (op3 + 20 > olimit) */ + movq %op3, %rax /* rax = op3 */ + cmpq %rax, %olimit /* op3 == olimit */ + je .L_4X1_exit + + /* If (ip1 < ip0) go to exit */ + cmpq %ip0, %ip1 + jb .L_4X1_exit + + /* If (ip2 < ip1) go to exit */ + cmpq %ip1, %ip2 + jb .L_4X1_exit + + /* If (ip3 < ip2) go to exit */ + cmpq %ip2, %ip3 + jb .L_4X1_exit + +/* Reads top 11 bits from bits[n] + * Loads dt[bits[n]] into var[n] + */ +#define GET_NEXT_DELT(n) \ + movq $53, %var##n; \ + shrxq %var##n, %bits##n, %var##n; \ + movzwl (%dtable,%var##n,2),%vard##n + +/* var[n] must contain the DTable entry computed with GET_NEXT_DELT + * Moves var[n] to %rax + * bits[n] <<= var[n] & 63 + * op[n][idx] = %rax >> 8 + * %ah is a way to access bits [8, 16) of %rax + */ +#define DECODE_FROM_DELT(n, idx) \ + movq %var##n, %rax; \ + shlxq %var##n, %bits##n, %bits##n; \ + movb %ah, idx(%op##n) + +/* Assumes GET_NEXT_DELT has been called. + * Calls DECODE_FROM_DELT then GET_NEXT_DELT + */ +#define DECODE_AND_GET_NEXT(n, idx) \ + DECODE_FROM_DELT(n, idx); \ + GET_NEXT_DELT(n) \ + +/* // ctz & nbBytes is stored in bits[n] + * // nbBits is stored in %rax + * ctz = CTZ[bits[n]] + * nbBits = ctz & 7 + * nbBytes = ctz >> 3 + * op[n] += 5 + * ip[n] -= nbBytes + * // Note: x86-64 is little-endian ==> no bswap + * bits[n] = MEM_readST(ip[n]) | 1 + * bits[n] <<= nbBits + */ +#define RELOAD_BITS(n) \ + bsfq %bits##n, %bits##n; \ + movq %bits##n, %rax; \ + andq $7, %rax; \ + shrq $3, %bits##n; \ + leaq 5(%op##n), %op##n; \ + subq %bits##n, %ip##n; \ + movq (%ip##n), %bits##n; \ + orq $1, %bits##n; \ + shlx %rax, %bits##n, %bits##n + + /* Store clobbered variables on the stack */ + movq %olimit, 24(%rsp) + movq %ip1, 0(%rsp) + movq %ip2, 8(%rsp) + movq %ip3, 16(%rsp) + + /* Call GET_NEXT_DELT for each stream */ + FOR_EACH_STREAM(GET_NEXT_DELT) + + .p2align 6 + +.L_4X1_loop_body: + /* Decode 5 symbols in each of the 4 streams (20 total) + * Must have called GET_NEXT_DELT for each stream + */ + FOR_EACH_STREAM_WITH_INDEX(DECODE_AND_GET_NEXT, 0) + FOR_EACH_STREAM_WITH_INDEX(DECODE_AND_GET_NEXT, 1) + FOR_EACH_STREAM_WITH_INDEX(DECODE_AND_GET_NEXT, 2) + FOR_EACH_STREAM_WITH_INDEX(DECODE_AND_GET_NEXT, 3) + FOR_EACH_STREAM_WITH_INDEX(DECODE_FROM_DELT, 4) + + /* Load ip[1,2,3] from stack (var[] aliases them) + * ip[] is needed for RELOAD_BITS + * Each will be stored back to the stack after RELOAD + */ + movq 0(%rsp), %ip1 + movq 8(%rsp), %ip2 + movq 16(%rsp), %ip3 + + /* Reload each stream & fetch the next table entry + * to prepare for the next iteration + */ + RELOAD_BITS(0) + GET_NEXT_DELT(0) + + RELOAD_BITS(1) + movq %ip1, 0(%rsp) + GET_NEXT_DELT(1) + + RELOAD_BITS(2) + movq %ip2, 8(%rsp) + GET_NEXT_DELT(2) + + RELOAD_BITS(3) + movq %ip3, 16(%rsp) + GET_NEXT_DELT(3) + + /* If op3 < olimit: continue the loop */ + cmp %op3, 24(%rsp) + ja .L_4X1_loop_body + + /* Reload ip[1,2,3] from stack */ + movq 0(%rsp), %ip1 + movq 8(%rsp), %ip2 + movq 16(%rsp), %ip3 + + /* Re-compute olimit */ + jmp .L_4X1_compute_olimit + +#undef GET_NEXT_DELT +#undef DECODE_FROM_DELT +#undef DECODE +#undef RELOAD_BITS +.L_4X1_exit: + addq $24, %rsp + + /* Restore stack (oend & olimit) */ + pop %rax /* olimit */ + pop %rax /* oend */ + pop %rax /* ilowest */ + pop %rax /* arg */ + + /* Save ip / op / bits */ + movq %ip0, 0(%rax) + movq %ip1, 8(%rax) + movq %ip2, 16(%rax) + movq %ip3, 24(%rax) + movq %op0, 32(%rax) + movq %op1, 40(%rax) + movq %op2, 48(%rax) + movq %op3, 56(%rax) + movq %bits0, 64(%rax) + movq %bits1, 72(%rax) + movq %bits2, 80(%rax) + movq %bits3, 88(%rax) + + /* Restore registers */ + pop %r15 + pop %r14 + pop %r13 + pop %r12 + pop %r11 + pop %r10 + pop %r9 + pop %r8 + pop %rdi + pop %rsi + pop %rbp + pop %rdx + pop %rcx + pop %rbx + pop %rax + ret + +_HUF_decompress4X2_usingDTable_internal_fast_asm_loop: +HUF_decompress4X2_usingDTable_internal_fast_asm_loop: + ZSTD_CET_ENDBRANCH + /* Save all registers - even if they are callee saved for simplicity. */ + push %rax + push %rbx + push %rcx + push %rdx + push %rbp + push %rsi + push %rdi + push %r8 + push %r9 + push %r10 + push %r11 + push %r12 + push %r13 + push %r14 + push %r15 + + movq %rdi, %rax + movq 0(%rax), %ip0 + movq 8(%rax), %ip1 + movq 16(%rax), %ip2 + movq 24(%rax), %ip3 + movq 32(%rax), %op0 + movq 40(%rax), %op1 + movq 48(%rax), %op2 + movq 56(%rax), %op3 + movq 64(%rax), %bits0 + movq 72(%rax), %bits1 + movq 80(%rax), %bits2 + movq 88(%rax), %bits3 + movq 96(%rax), %dtable + push %rax /* argument */ + push %rax /* olimit */ + push 104(%rax) /* ilowest */ + + movq 112(%rax), %rax + push %rax /* oend3 */ + + movq %op3, %rax + push %rax /* oend2 */ + + movq %op2, %rax + push %rax /* oend1 */ + + movq %op1, %rax + push %rax /* oend0 */ + + /* Scratch space */ + subq $8, %rsp + +.L_4X2_compute_olimit: + /* Computes how many iterations we can do safely + * %r15, %rax may be clobbered + * rdx must be saved + * op[1,2,3,4] & ip0 mustn't be clobbered + */ + movq %rdx, 0(%rsp) + + /* We can consume up to 7 input bytes each iteration. */ + movq %ip0, %rax /* rax = ip0 */ + movq 40(%rsp), %rdx /* rdx = ilowest */ + subq %rdx, %rax /* rax = ip0 - ilowest */ + movq %rax, %r15 /* r15 = ip0 - ilowest */ + + /* rdx = rax / 7 */ + movabsq $2635249153387078803, %rdx + mulq %rdx + subq %rdx, %r15 + shrq %r15 + addq %r15, %rdx + shrq $2, %rdx + + /* r15 = (ip0 - ilowest) / 7 */ + movq %rdx, %r15 + + /* r15 = min(r15, min(oend0 - op0, oend1 - op1, oend2 - op2, oend3 - op3) / 10) */ + movq 8(%rsp), %rax /* rax = oend0 */ + subq %op0, %rax /* rax = oend0 - op0 */ + movq 16(%rsp), %rdx /* rdx = oend1 */ + subq %op1, %rdx /* rdx = oend1 - op1 */ + + cmpq %rax, %rdx + cmova %rax, %rdx /* rdx = min(%rdx, %rax) */ + + movq 24(%rsp), %rax /* rax = oend2 */ + subq %op2, %rax /* rax = oend2 - op2 */ + + cmpq %rax, %rdx + cmova %rax, %rdx /* rdx = min(%rdx, %rax) */ + + movq 32(%rsp), %rax /* rax = oend3 */ + subq %op3, %rax /* rax = oend3 - op3 */ + + cmpq %rax, %rdx + cmova %rax, %rdx /* rdx = min(%rdx, %rax) */ + + movabsq $-3689348814741910323, %rax + mulq %rdx + shrq $3, %rdx /* rdx = rdx / 10 */ + + /* r15 = min(%rdx, %r15) */ + cmpq %rdx, %r15 + cmova %rdx, %r15 + + /* olimit = op3 + 5 * r15 */ + movq %r15, %rax + leaq (%op3, %rax, 4), %olimit + addq %rax, %olimit + + movq 0(%rsp), %rdx + + /* If (op3 + 10 > olimit) */ + movq %op3, %rax /* rax = op3 */ + cmpq %rax, %olimit /* op3 == olimit */ + je .L_4X2_exit + + /* If (ip1 < ip0) go to exit */ + cmpq %ip0, %ip1 + jb .L_4X2_exit + + /* If (ip2 < ip1) go to exit */ + cmpq %ip1, %ip2 + jb .L_4X2_exit + + /* If (ip3 < ip2) go to exit */ + cmpq %ip2, %ip3 + jb .L_4X2_exit + +#define DECODE(n, idx) \ + movq %bits##n, %rax; \ + shrq $53, %rax; \ + movzwl 0(%dtable,%rax,4),%r8d; \ + movzbl 2(%dtable,%rax,4),%r15d; \ + movzbl 3(%dtable,%rax,4),%eax; \ + movw %r8w, (%op##n); \ + shlxq %r15, %bits##n, %bits##n; \ + addq %rax, %op##n + +#define RELOAD_BITS(n) \ + bsfq %bits##n, %bits##n; \ + movq %bits##n, %rax; \ + shrq $3, %bits##n; \ + andq $7, %rax; \ + subq %bits##n, %ip##n; \ + movq (%ip##n), %bits##n; \ + orq $1, %bits##n; \ + shlxq %rax, %bits##n, %bits##n + + + movq %olimit, 48(%rsp) + + .p2align 6 + +.L_4X2_loop_body: + /* We clobber r8, so store it on the stack */ + movq %r8, 0(%rsp) + + /* Decode 5 symbols from each of the 4 streams (20 symbols total). */ + FOR_EACH_STREAM_WITH_INDEX(DECODE, 0) + FOR_EACH_STREAM_WITH_INDEX(DECODE, 1) + FOR_EACH_STREAM_WITH_INDEX(DECODE, 2) + FOR_EACH_STREAM_WITH_INDEX(DECODE, 3) + FOR_EACH_STREAM_WITH_INDEX(DECODE, 4) + + /* Reload r8 */ + movq 0(%rsp), %r8 + + FOR_EACH_STREAM(RELOAD_BITS) + + cmp %op3, 48(%rsp) + ja .L_4X2_loop_body + jmp .L_4X2_compute_olimit + +#undef DECODE +#undef RELOAD_BITS +.L_4X2_exit: + addq $8, %rsp + /* Restore stack (oend & olimit) */ + pop %rax /* oend0 */ + pop %rax /* oend1 */ + pop %rax /* oend2 */ + pop %rax /* oend3 */ + pop %rax /* ilowest */ + pop %rax /* olimit */ + pop %rax /* arg */ + + /* Save ip / op / bits */ + movq %ip0, 0(%rax) + movq %ip1, 8(%rax) + movq %ip2, 16(%rax) + movq %ip3, 24(%rax) + movq %op0, 32(%rax) + movq %op1, 40(%rax) + movq %op2, 48(%rax) + movq %op3, 56(%rax) + movq %bits0, 64(%rax) + movq %bits1, 72(%rax) + movq %bits2, 80(%rax) + movq %bits3, 88(%rax) + + /* Restore registers */ + pop %r15 + pop %r14 + pop %r13 + pop %r12 + pop %r11 + pop %r10 + pop %r9 + pop %r8 + pop %rdi + pop %rsi + pop %rbp + pop %rdx + pop %rcx + pop %rbx + pop %rax + ret + +#endif diff --git a/third_party/zstd/lib/decompress/zstd_ddict.c b/third_party/zstd/lib/decompress/zstd_ddict.c new file mode 100644 index 0000000000..309ec0d036 --- /dev/null +++ b/third_party/zstd/lib/decompress/zstd_ddict.c @@ -0,0 +1,244 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + +/* zstd_ddict.c : + * concentrates all logic that needs to know the internals of ZSTD_DDict object */ + +/*-******************************************************* +* Dependencies +*********************************************************/ +#include "../common/allocations.h" /* ZSTD_customMalloc, ZSTD_customFree */ +#include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memmove, ZSTD_memset */ +#include "../common/cpu.h" /* bmi2 */ +#include "../common/mem.h" /* low level memory routines */ +#define FSE_STATIC_LINKING_ONLY +#include "../common/fse.h" +#include "../common/huf.h" +#include "zstd_decompress_internal.h" +#include "zstd_ddict.h" + +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) +# include "../legacy/zstd_legacy.h" +#endif + + + +/*-******************************************************* +* Types +*********************************************************/ +struct ZSTD_DDict_s { + void* dictBuffer; + const void* dictContent; + size_t dictSize; + ZSTD_entropyDTables_t entropy; + U32 dictID; + U32 entropyPresent; + ZSTD_customMem cMem; +}; /* typedef'd to ZSTD_DDict within "zstd.h" */ + +const void* ZSTD_DDict_dictContent(const ZSTD_DDict* ddict) +{ + assert(ddict != NULL); + return ddict->dictContent; +} + +size_t ZSTD_DDict_dictSize(const ZSTD_DDict* ddict) +{ + assert(ddict != NULL); + return ddict->dictSize; +} + +void ZSTD_copyDDictParameters(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict) +{ + DEBUGLOG(4, "ZSTD_copyDDictParameters"); + assert(dctx != NULL); + assert(ddict != NULL); + dctx->dictID = ddict->dictID; + dctx->prefixStart = ddict->dictContent; + dctx->virtualStart = ddict->dictContent; + dctx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize; + dctx->previousDstEnd = dctx->dictEnd; +#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + dctx->dictContentBeginForFuzzing = dctx->prefixStart; + dctx->dictContentEndForFuzzing = dctx->previousDstEnd; +#endif + if (ddict->entropyPresent) { + dctx->litEntropy = 1; + dctx->fseEntropy = 1; + dctx->LLTptr = ddict->entropy.LLTable; + dctx->MLTptr = ddict->entropy.MLTable; + dctx->OFTptr = ddict->entropy.OFTable; + dctx->HUFptr = ddict->entropy.hufTable; + dctx->entropy.rep[0] = ddict->entropy.rep[0]; + dctx->entropy.rep[1] = ddict->entropy.rep[1]; + dctx->entropy.rep[2] = ddict->entropy.rep[2]; + } else { + dctx->litEntropy = 0; + dctx->fseEntropy = 0; + } +} + + +static size_t +ZSTD_loadEntropy_intoDDict(ZSTD_DDict* ddict, + ZSTD_dictContentType_e dictContentType) +{ + ddict->dictID = 0; + ddict->entropyPresent = 0; + if (dictContentType == ZSTD_dct_rawContent) return 0; + + if (ddict->dictSize < 8) { + if (dictContentType == ZSTD_dct_fullDict) + return ERROR(dictionary_corrupted); /* only accept specified dictionaries */ + return 0; /* pure content mode */ + } + { U32 const magic = MEM_readLE32(ddict->dictContent); + if (magic != ZSTD_MAGIC_DICTIONARY) { + if (dictContentType == ZSTD_dct_fullDict) + return ERROR(dictionary_corrupted); /* only accept specified dictionaries */ + return 0; /* pure content mode */ + } + } + ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_FRAMEIDSIZE); + + /* load entropy tables */ + RETURN_ERROR_IF(ZSTD_isError(ZSTD_loadDEntropy( + &ddict->entropy, ddict->dictContent, ddict->dictSize)), + dictionary_corrupted, ""); + ddict->entropyPresent = 1; + return 0; +} + + +static size_t ZSTD_initDDict_internal(ZSTD_DDict* ddict, + const void* dict, size_t dictSize, + ZSTD_dictLoadMethod_e dictLoadMethod, + ZSTD_dictContentType_e dictContentType) +{ + if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dict) || (!dictSize)) { + ddict->dictBuffer = NULL; + ddict->dictContent = dict; + if (!dict) dictSize = 0; + } else { + void* const internalBuffer = ZSTD_customMalloc(dictSize, ddict->cMem); + ddict->dictBuffer = internalBuffer; + ddict->dictContent = internalBuffer; + if (!internalBuffer) return ERROR(memory_allocation); + ZSTD_memcpy(internalBuffer, dict, dictSize); + } + ddict->dictSize = dictSize; + ddict->entropy.hufTable[0] = (HUF_DTable)((ZSTD_HUFFDTABLE_CAPACITY_LOG)*0x1000001); /* cover both little and big endian */ + + /* parse dictionary content */ + FORWARD_IF_ERROR( ZSTD_loadEntropy_intoDDict(ddict, dictContentType) , ""); + + return 0; +} + +ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize, + ZSTD_dictLoadMethod_e dictLoadMethod, + ZSTD_dictContentType_e dictContentType, + ZSTD_customMem customMem) +{ + if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL; + + { ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_customMalloc(sizeof(ZSTD_DDict), customMem); + if (ddict == NULL) return NULL; + ddict->cMem = customMem; + { size_t const initResult = ZSTD_initDDict_internal(ddict, + dict, dictSize, + dictLoadMethod, dictContentType); + if (ZSTD_isError(initResult)) { + ZSTD_freeDDict(ddict); + return NULL; + } } + return ddict; + } +} + +/*! ZSTD_createDDict() : +* Create a digested dictionary, to start decompression without startup delay. +* `dict` content is copied inside DDict. +* Consequently, `dict` can be released after `ZSTD_DDict` creation */ +ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize) +{ + ZSTD_customMem const allocator = { NULL, NULL, NULL }; + return ZSTD_createDDict_advanced(dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto, allocator); +} + +/*! ZSTD_createDDict_byReference() : + * Create a digested dictionary, to start decompression without startup delay. + * Dictionary content is simply referenced, it will be accessed during decompression. + * Warning : dictBuffer must outlive DDict (DDict must be freed before dictBuffer) */ +ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize) +{ + ZSTD_customMem const allocator = { NULL, NULL, NULL }; + return ZSTD_createDDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto, allocator); +} + + +const ZSTD_DDict* ZSTD_initStaticDDict( + void* sBuffer, size_t sBufferSize, + const void* dict, size_t dictSize, + ZSTD_dictLoadMethod_e dictLoadMethod, + ZSTD_dictContentType_e dictContentType) +{ + size_t const neededSpace = sizeof(ZSTD_DDict) + + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize); + ZSTD_DDict* const ddict = (ZSTD_DDict*)sBuffer; + assert(sBuffer != NULL); + assert(dict != NULL); + if ((size_t)sBuffer & 7) return NULL; /* 8-aligned */ + if (sBufferSize < neededSpace) return NULL; + if (dictLoadMethod == ZSTD_dlm_byCopy) { + ZSTD_memcpy(ddict+1, dict, dictSize); /* local copy */ + dict = ddict+1; + } + if (ZSTD_isError( ZSTD_initDDict_internal(ddict, + dict, dictSize, + ZSTD_dlm_byRef, dictContentType) )) + return NULL; + return ddict; +} + + +size_t ZSTD_freeDDict(ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; /* support free on NULL */ + { ZSTD_customMem const cMem = ddict->cMem; + ZSTD_customFree(ddict->dictBuffer, cMem); + ZSTD_customFree(ddict, cMem); + return 0; + } +} + +/*! ZSTD_estimateDDictSize() : + * Estimate amount of memory that will be needed to create a dictionary for decompression. + * Note : dictionary created by reference using ZSTD_dlm_byRef are smaller */ +size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod) +{ + return sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize); +} + +size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; /* support sizeof on NULL */ + return sizeof(*ddict) + (ddict->dictBuffer ? ddict->dictSize : 0) ; +} + +/*! ZSTD_getDictID_fromDDict() : + * Provides the dictID of the dictionary loaded into `ddict`. + * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty. + * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */ +unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; + return ddict->dictID; +} diff --git a/third_party/zstd/lib/decompress/zstd_ddict.h b/third_party/zstd/lib/decompress/zstd_ddict.h new file mode 100644 index 0000000000..c4ca8877a0 --- /dev/null +++ b/third_party/zstd/lib/decompress/zstd_ddict.h @@ -0,0 +1,44 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + + +#ifndef ZSTD_DDICT_H +#define ZSTD_DDICT_H + +/*-******************************************************* + * Dependencies + *********************************************************/ +#include "../common/zstd_deps.h" /* size_t */ +#include "../zstd.h" /* ZSTD_DDict, and several public functions */ + + +/*-******************************************************* + * Interface + *********************************************************/ + +/* note: several prototypes are already published in `zstd.h` : + * ZSTD_createDDict() + * ZSTD_createDDict_byReference() + * ZSTD_createDDict_advanced() + * ZSTD_freeDDict() + * ZSTD_initStaticDDict() + * ZSTD_sizeof_DDict() + * ZSTD_estimateDDictSize() + * ZSTD_getDictID_fromDict() + */ + +const void* ZSTD_DDict_dictContent(const ZSTD_DDict* ddict); +size_t ZSTD_DDict_dictSize(const ZSTD_DDict* ddict); + +void ZSTD_copyDDictParameters(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict); + + + +#endif /* ZSTD_DDICT_H */ diff --git a/third_party/zstd/lib/decompress/zstd_decompress.c b/third_party/zstd/lib/decompress/zstd_decompress.c new file mode 100644 index 0000000000..2f03cf7b0c --- /dev/null +++ b/third_party/zstd/lib/decompress/zstd_decompress.c @@ -0,0 +1,2407 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + + +/* *************************************************************** +* Tuning parameters +*****************************************************************/ +/*! + * HEAPMODE : + * Select how default decompression function ZSTD_decompress() allocates its context, + * on stack (0), or into heap (1, default; requires malloc()). + * Note that functions with explicit context such as ZSTD_decompressDCtx() are unaffected. + */ +#ifndef ZSTD_HEAPMODE +# define ZSTD_HEAPMODE 1 +#endif + +/*! +* LEGACY_SUPPORT : +* if set to 1+, ZSTD_decompress() can decode older formats (v0.1+) +*/ +#ifndef ZSTD_LEGACY_SUPPORT +# define ZSTD_LEGACY_SUPPORT 0 +#endif + +/*! + * MAXWINDOWSIZE_DEFAULT : + * maximum window size accepted by DStream __by default__. + * Frames requiring more memory will be rejected. + * It's possible to set a different limit using ZSTD_DCtx_setMaxWindowSize(). + */ +#ifndef ZSTD_MAXWINDOWSIZE_DEFAULT +# define ZSTD_MAXWINDOWSIZE_DEFAULT (((U32)1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT) + 1) +#endif + +/*! + * NO_FORWARD_PROGRESS_MAX : + * maximum allowed nb of calls to ZSTD_decompressStream() + * without any forward progress + * (defined as: no byte read from input, and no byte flushed to output) + * before triggering an error. + */ +#ifndef ZSTD_NO_FORWARD_PROGRESS_MAX +# define ZSTD_NO_FORWARD_PROGRESS_MAX 16 +#endif + + +/*-******************************************************* +* Dependencies +*********************************************************/ +#include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memmove, ZSTD_memset */ +#include "../common/allocations.h" /* ZSTD_customMalloc, ZSTD_customCalloc, ZSTD_customFree */ +#include "../common/error_private.h" +#include "../common/zstd_internal.h" /* blockProperties_t */ +#include "../common/mem.h" /* low level memory routines */ +#include "../common/bits.h" /* ZSTD_highbit32 */ +#define FSE_STATIC_LINKING_ONLY +#include "../common/fse.h" +#include "../common/huf.h" +#include "../common/xxhash.h" /* XXH64_reset, XXH64_update, XXH64_digest, XXH64 */ +#include "zstd_decompress_internal.h" /* ZSTD_DCtx */ +#include "zstd_ddict.h" /* ZSTD_DDictDictContent */ +#include "zstd_decompress_block.h" /* ZSTD_decompressBlock_internal */ + +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) +# include "../legacy/zstd_legacy.h" +#endif + + + +/************************************* + * Multiple DDicts Hashset internals * + *************************************/ + +#define DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT 4 +#define DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT 3 /* These two constants represent SIZE_MULT/COUNT_MULT load factor without using a float. + * Currently, that means a 0.75 load factor. + * So, if count * COUNT_MULT / size * SIZE_MULT != 0, then we've exceeded + * the load factor of the ddict hash set. + */ + +#define DDICT_HASHSET_TABLE_BASE_SIZE 64 +#define DDICT_HASHSET_RESIZE_FACTOR 2 + +/* Hash function to determine starting position of dict insertion within the table + * Returns an index between [0, hashSet->ddictPtrTableSize] + */ +static size_t ZSTD_DDictHashSet_getIndex(const ZSTD_DDictHashSet* hashSet, U32 dictID) { + const U64 hash = XXH64(&dictID, sizeof(U32), 0); + /* DDict ptr table size is a multiple of 2, use size - 1 as mask to get index within [0, hashSet->ddictPtrTableSize) */ + return hash & (hashSet->ddictPtrTableSize - 1); +} + +/* Adds DDict to a hashset without resizing it. + * If inserting a DDict with a dictID that already exists in the set, replaces the one in the set. + * Returns 0 if successful, or a zstd error code if something went wrong. + */ +static size_t ZSTD_DDictHashSet_emplaceDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict) { + const U32 dictID = ZSTD_getDictID_fromDDict(ddict); + size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID); + const size_t idxRangeMask = hashSet->ddictPtrTableSize - 1; + RETURN_ERROR_IF(hashSet->ddictPtrCount == hashSet->ddictPtrTableSize, GENERIC, "Hash set is full!"); + DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx); + while (hashSet->ddictPtrTable[idx] != NULL) { + /* Replace existing ddict if inserting ddict with same dictID */ + if (ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]) == dictID) { + DEBUGLOG(4, "DictID already exists, replacing rather than adding"); + hashSet->ddictPtrTable[idx] = ddict; + return 0; + } + idx &= idxRangeMask; + idx++; + } + DEBUGLOG(4, "Final idx after probing for dictID %u is: %zu", dictID, idx); + hashSet->ddictPtrTable[idx] = ddict; + hashSet->ddictPtrCount++; + return 0; +} + +/* Expands hash table by factor of DDICT_HASHSET_RESIZE_FACTOR and + * rehashes all values, allocates new table, frees old table. + * Returns 0 on success, otherwise a zstd error code. + */ +static size_t ZSTD_DDictHashSet_expand(ZSTD_DDictHashSet* hashSet, ZSTD_customMem customMem) { + size_t newTableSize = hashSet->ddictPtrTableSize * DDICT_HASHSET_RESIZE_FACTOR; + const ZSTD_DDict** newTable = (const ZSTD_DDict**)ZSTD_customCalloc(sizeof(ZSTD_DDict*) * newTableSize, customMem); + const ZSTD_DDict** oldTable = hashSet->ddictPtrTable; + size_t oldTableSize = hashSet->ddictPtrTableSize; + size_t i; + + DEBUGLOG(4, "Expanding DDict hash table! Old size: %zu new size: %zu", oldTableSize, newTableSize); + RETURN_ERROR_IF(!newTable, memory_allocation, "Expanded hashset allocation failed!"); + hashSet->ddictPtrTable = newTable; + hashSet->ddictPtrTableSize = newTableSize; + hashSet->ddictPtrCount = 0; + for (i = 0; i < oldTableSize; ++i) { + if (oldTable[i] != NULL) { + FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, oldTable[i]), ""); + } + } + ZSTD_customFree((void*)oldTable, customMem); + DEBUGLOG(4, "Finished re-hash"); + return 0; +} + +/* Fetches a DDict with the given dictID + * Returns the ZSTD_DDict* with the requested dictID. If it doesn't exist, then returns NULL. + */ +static const ZSTD_DDict* ZSTD_DDictHashSet_getDDict(ZSTD_DDictHashSet* hashSet, U32 dictID) { + size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID); + const size_t idxRangeMask = hashSet->ddictPtrTableSize - 1; + DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx); + for (;;) { + size_t currDictID = ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]); + if (currDictID == dictID || currDictID == 0) { + /* currDictID == 0 implies a NULL ddict entry */ + break; + } else { + idx &= idxRangeMask; /* Goes to start of table when we reach the end */ + idx++; + } + } + DEBUGLOG(4, "Final idx after probing for dictID %u is: %zu", dictID, idx); + return hashSet->ddictPtrTable[idx]; +} + +/* Allocates space for and returns a ddict hash set + * The hash set's ZSTD_DDict* table has all values automatically set to NULL to begin with. + * Returns NULL if allocation failed. + */ +static ZSTD_DDictHashSet* ZSTD_createDDictHashSet(ZSTD_customMem customMem) { + ZSTD_DDictHashSet* ret = (ZSTD_DDictHashSet*)ZSTD_customMalloc(sizeof(ZSTD_DDictHashSet), customMem); + DEBUGLOG(4, "Allocating new hash set"); + if (!ret) + return NULL; + ret->ddictPtrTable = (const ZSTD_DDict**)ZSTD_customCalloc(DDICT_HASHSET_TABLE_BASE_SIZE * sizeof(ZSTD_DDict*), customMem); + if (!ret->ddictPtrTable) { + ZSTD_customFree(ret, customMem); + return NULL; + } + ret->ddictPtrTableSize = DDICT_HASHSET_TABLE_BASE_SIZE; + ret->ddictPtrCount = 0; + return ret; +} + +/* Frees the table of ZSTD_DDict* within a hashset, then frees the hashset itself. + * Note: The ZSTD_DDict* within the table are NOT freed. + */ +static void ZSTD_freeDDictHashSet(ZSTD_DDictHashSet* hashSet, ZSTD_customMem customMem) { + DEBUGLOG(4, "Freeing ddict hash set"); + if (hashSet && hashSet->ddictPtrTable) { + ZSTD_customFree((void*)hashSet->ddictPtrTable, customMem); + } + if (hashSet) { + ZSTD_customFree(hashSet, customMem); + } +} + +/* Public function: Adds a DDict into the ZSTD_DDictHashSet, possibly triggering a resize of the hash set. + * Returns 0 on success, or a ZSTD error. + */ +static size_t ZSTD_DDictHashSet_addDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict, ZSTD_customMem customMem) { + DEBUGLOG(4, "Adding dict ID: %u to hashset with - Count: %zu Tablesize: %zu", ZSTD_getDictID_fromDDict(ddict), hashSet->ddictPtrCount, hashSet->ddictPtrTableSize); + if (hashSet->ddictPtrCount * DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT / hashSet->ddictPtrTableSize * DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT != 0) { + FORWARD_IF_ERROR(ZSTD_DDictHashSet_expand(hashSet, customMem), ""); + } + FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, ddict), ""); + return 0; +} + +/*-************************************************************* +* Context management +***************************************************************/ +size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx) +{ + if (dctx==NULL) return 0; /* support sizeof NULL */ + return sizeof(*dctx) + + ZSTD_sizeof_DDict(dctx->ddictLocal) + + dctx->inBuffSize + dctx->outBuffSize; +} + +size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); } + + +static size_t ZSTD_startingInputLength(ZSTD_format_e format) +{ + size_t const startingInputLength = ZSTD_FRAMEHEADERSIZE_PREFIX(format); + /* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */ + assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) ); + return startingInputLength; +} + +static void ZSTD_DCtx_resetParameters(ZSTD_DCtx* dctx) +{ + assert(dctx->streamStage == zdss_init); + dctx->format = ZSTD_f_zstd1; + dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT; + dctx->outBufferMode = ZSTD_bm_buffered; + dctx->forceIgnoreChecksum = ZSTD_d_validateChecksum; + dctx->refMultipleDDicts = ZSTD_rmd_refSingleDDict; + dctx->disableHufAsm = 0; + dctx->maxBlockSizeParam = 0; +} + +static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx) +{ + dctx->staticSize = 0; + dctx->ddict = NULL; + dctx->ddictLocal = NULL; + dctx->dictEnd = NULL; + dctx->ddictIsCold = 0; + dctx->dictUses = ZSTD_dont_use; + dctx->inBuff = NULL; + dctx->inBuffSize = 0; + dctx->outBuffSize = 0; + dctx->streamStage = zdss_init; +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) + dctx->legacyContext = NULL; + dctx->previousLegacyVersion = 0; +#endif + dctx->noForwardProgress = 0; + dctx->oversizedDuration = 0; + dctx->isFrameDecompression = 1; +#if DYNAMIC_BMI2 + dctx->bmi2 = ZSTD_cpuSupportsBmi2(); +#endif + dctx->ddictSet = NULL; + ZSTD_DCtx_resetParameters(dctx); +#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + dctx->dictContentEndForFuzzing = NULL; +#endif +} + +ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize) +{ + ZSTD_DCtx* const dctx = (ZSTD_DCtx*) workspace; + + if ((size_t)workspace & 7) return NULL; /* 8-aligned */ + if (workspaceSize < sizeof(ZSTD_DCtx)) return NULL; /* minimum size */ + + ZSTD_initDCtx_internal(dctx); + dctx->staticSize = workspaceSize; + dctx->inBuff = (char*)(dctx+1); + return dctx; +} + +static ZSTD_DCtx* ZSTD_createDCtx_internal(ZSTD_customMem customMem) { + if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL; + + { ZSTD_DCtx* const dctx = (ZSTD_DCtx*)ZSTD_customMalloc(sizeof(*dctx), customMem); + if (!dctx) return NULL; + dctx->customMem = customMem; + ZSTD_initDCtx_internal(dctx); + return dctx; + } +} + +ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem) +{ + return ZSTD_createDCtx_internal(customMem); +} + +ZSTD_DCtx* ZSTD_createDCtx(void) +{ + DEBUGLOG(3, "ZSTD_createDCtx"); + return ZSTD_createDCtx_internal(ZSTD_defaultCMem); +} + +static void ZSTD_clearDict(ZSTD_DCtx* dctx) +{ + ZSTD_freeDDict(dctx->ddictLocal); + dctx->ddictLocal = NULL; + dctx->ddict = NULL; + dctx->dictUses = ZSTD_dont_use; +} + +size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx) +{ + if (dctx==NULL) return 0; /* support free on NULL */ + RETURN_ERROR_IF(dctx->staticSize, memory_allocation, "not compatible with static DCtx"); + { ZSTD_customMem const cMem = dctx->customMem; + ZSTD_clearDict(dctx); + ZSTD_customFree(dctx->inBuff, cMem); + dctx->inBuff = NULL; +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (dctx->legacyContext) + ZSTD_freeLegacyStreamContext(dctx->legacyContext, dctx->previousLegacyVersion); +#endif + if (dctx->ddictSet) { + ZSTD_freeDDictHashSet(dctx->ddictSet, cMem); + dctx->ddictSet = NULL; + } + ZSTD_customFree(dctx, cMem); + return 0; + } +} + +/* no longer useful */ +void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx) +{ + size_t const toCopy = (size_t)((char*)(&dstDCtx->inBuff) - (char*)dstDCtx); + ZSTD_memcpy(dstDCtx, srcDCtx, toCopy); /* no need to copy workspace */ +} + +/* Given a dctx with a digested frame params, re-selects the correct ZSTD_DDict based on + * the requested dict ID from the frame. If there exists a reference to the correct ZSTD_DDict, then + * accordingly sets the ddict to be used to decompress the frame. + * + * If no DDict is found, then no action is taken, and the ZSTD_DCtx::ddict remains as-is. + * + * ZSTD_d_refMultipleDDicts must be enabled for this function to be called. + */ +static void ZSTD_DCtx_selectFrameDDict(ZSTD_DCtx* dctx) { + assert(dctx->refMultipleDDicts && dctx->ddictSet); + DEBUGLOG(4, "Adjusting DDict based on requested dict ID from frame"); + if (dctx->ddict) { + const ZSTD_DDict* frameDDict = ZSTD_DDictHashSet_getDDict(dctx->ddictSet, dctx->fParams.dictID); + if (frameDDict) { + DEBUGLOG(4, "DDict found!"); + ZSTD_clearDict(dctx); + dctx->dictID = dctx->fParams.dictID; + dctx->ddict = frameDDict; + dctx->dictUses = ZSTD_use_indefinitely; + } + } +} + + +/*-************************************************************* + * Frame header decoding + ***************************************************************/ + +/*! ZSTD_isFrame() : + * Tells if the content of `buffer` starts with a valid Frame Identifier. + * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0. + * Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled. + * Note 3 : Skippable Frame Identifiers are considered valid. */ +unsigned ZSTD_isFrame(const void* buffer, size_t size) +{ + if (size < ZSTD_FRAMEIDSIZE) return 0; + { U32 const magic = MEM_readLE32(buffer); + if (magic == ZSTD_MAGICNUMBER) return 1; + if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1; + } +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (ZSTD_isLegacy(buffer, size)) return 1; +#endif + return 0; +} + +/*! ZSTD_isSkippableFrame() : + * Tells if the content of `buffer` starts with a valid Frame Identifier for a skippable frame. + * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0. + */ +unsigned ZSTD_isSkippableFrame(const void* buffer, size_t size) +{ + if (size < ZSTD_FRAMEIDSIZE) return 0; + { U32 const magic = MEM_readLE32(buffer); + if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1; + } + return 0; +} + +/** ZSTD_frameHeaderSize_internal() : + * srcSize must be large enough to reach header size fields. + * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless. + * @return : size of the Frame Header + * or an error code, which can be tested with ZSTD_isError() */ +static size_t ZSTD_frameHeaderSize_internal(const void* src, size_t srcSize, ZSTD_format_e format) +{ + size_t const minInputSize = ZSTD_startingInputLength(format); + RETURN_ERROR_IF(srcSize < minInputSize, srcSize_wrong, ""); + + { BYTE const fhd = ((const BYTE*)src)[minInputSize-1]; + U32 const dictID= fhd & 3; + U32 const singleSegment = (fhd >> 5) & 1; + U32 const fcsId = fhd >> 6; + return minInputSize + !singleSegment + + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId] + + (singleSegment && !fcsId); + } +} + +/** ZSTD_frameHeaderSize() : + * srcSize must be >= ZSTD_frameHeaderSize_prefix. + * @return : size of the Frame Header, + * or an error code (if srcSize is too small) */ +size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize) +{ + return ZSTD_frameHeaderSize_internal(src, srcSize, ZSTD_f_zstd1); +} + + +/** ZSTD_getFrameHeader_advanced() : + * decode Frame Header, or require larger `srcSize`. + * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless + * @return : 0, `zfhPtr` is correctly filled, + * >0, `srcSize` is too small, value is wanted `srcSize` amount, +** or an error code, which can be tested using ZSTD_isError() */ +size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format) +{ + const BYTE* ip = (const BYTE*)src; + size_t const minInputSize = ZSTD_startingInputLength(format); + + DEBUGLOG(5, "ZSTD_getFrameHeader_advanced: minInputSize = %zu, srcSize = %zu", minInputSize, srcSize); + + if (srcSize > 0) { + /* note : technically could be considered an assert(), since it's an invalid entry */ + RETURN_ERROR_IF(src==NULL, GENERIC, "invalid parameter : src==NULL, but srcSize>0"); + } + if (srcSize < minInputSize) { + if (srcSize > 0 && format != ZSTD_f_zstd1_magicless) { + /* when receiving less than @minInputSize bytes, + * control these bytes at least correspond to a supported magic number + * in order to error out early if they don't. + **/ + size_t const toCopy = MIN(4, srcSize); + unsigned char hbuf[4]; MEM_writeLE32(hbuf, ZSTD_MAGICNUMBER); + assert(src != NULL); + ZSTD_memcpy(hbuf, src, toCopy); + if ( MEM_readLE32(hbuf) != ZSTD_MAGICNUMBER ) { + /* not a zstd frame : let's check if it's a skippable frame */ + MEM_writeLE32(hbuf, ZSTD_MAGIC_SKIPPABLE_START); + ZSTD_memcpy(hbuf, src, toCopy); + if ((MEM_readLE32(hbuf) & ZSTD_MAGIC_SKIPPABLE_MASK) != ZSTD_MAGIC_SKIPPABLE_START) { + RETURN_ERROR(prefix_unknown, + "first bytes don't correspond to any supported magic number"); + } } } + return minInputSize; + } + + ZSTD_memset(zfhPtr, 0, sizeof(*zfhPtr)); /* not strictly necessary, but static analyzers may not understand that zfhPtr will be read only if return value is zero, since they are 2 different signals */ + if ( (format != ZSTD_f_zstd1_magicless) + && (MEM_readLE32(src) != ZSTD_MAGICNUMBER) ) { + if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { + /* skippable frame */ + if (srcSize < ZSTD_SKIPPABLEHEADERSIZE) + return ZSTD_SKIPPABLEHEADERSIZE; /* magic number + frame length */ + ZSTD_memset(zfhPtr, 0, sizeof(*zfhPtr)); + zfhPtr->frameContentSize = MEM_readLE32((const char *)src + ZSTD_FRAMEIDSIZE); + zfhPtr->frameType = ZSTD_skippableFrame; + return 0; + } + RETURN_ERROR(prefix_unknown, ""); + } + + /* ensure there is enough `srcSize` to fully read/decode frame header */ + { size_t const fhsize = ZSTD_frameHeaderSize_internal(src, srcSize, format); + if (srcSize < fhsize) return fhsize; + zfhPtr->headerSize = (U32)fhsize; + } + + { BYTE const fhdByte = ip[minInputSize-1]; + size_t pos = minInputSize; + U32 const dictIDSizeCode = fhdByte&3; + U32 const checksumFlag = (fhdByte>>2)&1; + U32 const singleSegment = (fhdByte>>5)&1; + U32 const fcsID = fhdByte>>6; + U64 windowSize = 0; + U32 dictID = 0; + U64 frameContentSize = ZSTD_CONTENTSIZE_UNKNOWN; + RETURN_ERROR_IF((fhdByte & 0x08) != 0, frameParameter_unsupported, + "reserved bits, must be zero"); + + if (!singleSegment) { + BYTE const wlByte = ip[pos++]; + U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN; + RETURN_ERROR_IF(windowLog > ZSTD_WINDOWLOG_MAX, frameParameter_windowTooLarge, ""); + windowSize = (1ULL << windowLog); + windowSize += (windowSize >> 3) * (wlByte&7); + } + switch(dictIDSizeCode) + { + default: + assert(0); /* impossible */ + ZSTD_FALLTHROUGH; + case 0 : break; + case 1 : dictID = ip[pos]; pos++; break; + case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break; + case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break; + } + switch(fcsID) + { + default: + assert(0); /* impossible */ + ZSTD_FALLTHROUGH; + case 0 : if (singleSegment) frameContentSize = ip[pos]; break; + case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break; + case 2 : frameContentSize = MEM_readLE32(ip+pos); break; + case 3 : frameContentSize = MEM_readLE64(ip+pos); break; + } + if (singleSegment) windowSize = frameContentSize; + + zfhPtr->frameType = ZSTD_frame; + zfhPtr->frameContentSize = frameContentSize; + zfhPtr->windowSize = windowSize; + zfhPtr->blockSizeMax = (unsigned) MIN(windowSize, ZSTD_BLOCKSIZE_MAX); + zfhPtr->dictID = dictID; + zfhPtr->checksumFlag = checksumFlag; + } + return 0; +} + +/** ZSTD_getFrameHeader() : + * decode Frame Header, or require larger `srcSize`. + * note : this function does not consume input, it only reads it. + * @return : 0, `zfhPtr` is correctly filled, + * >0, `srcSize` is too small, value is wanted `srcSize` amount, + * or an error code, which can be tested using ZSTD_isError() */ +size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize) +{ + return ZSTD_getFrameHeader_advanced(zfhPtr, src, srcSize, ZSTD_f_zstd1); +} + +/** ZSTD_getFrameContentSize() : + * compatible with legacy mode + * @return : decompressed size of the single frame pointed to be `src` if known, otherwise + * - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined + * - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */ +unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize) +{ +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (ZSTD_isLegacy(src, srcSize)) { + unsigned long long const ret = ZSTD_getDecompressedSize_legacy(src, srcSize); + return ret == 0 ? ZSTD_CONTENTSIZE_UNKNOWN : ret; + } +#endif + { ZSTD_frameHeader zfh; + if (ZSTD_getFrameHeader(&zfh, src, srcSize) != 0) + return ZSTD_CONTENTSIZE_ERROR; + if (zfh.frameType == ZSTD_skippableFrame) { + return 0; + } else { + return zfh.frameContentSize; + } } +} + +static size_t readSkippableFrameSize(void const* src, size_t srcSize) +{ + size_t const skippableHeaderSize = ZSTD_SKIPPABLEHEADERSIZE; + U32 sizeU32; + + RETURN_ERROR_IF(srcSize < ZSTD_SKIPPABLEHEADERSIZE, srcSize_wrong, ""); + + sizeU32 = MEM_readLE32((BYTE const*)src + ZSTD_FRAMEIDSIZE); + RETURN_ERROR_IF((U32)(sizeU32 + ZSTD_SKIPPABLEHEADERSIZE) < sizeU32, + frameParameter_unsupported, ""); + { size_t const skippableSize = skippableHeaderSize + sizeU32; + RETURN_ERROR_IF(skippableSize > srcSize, srcSize_wrong, ""); + return skippableSize; + } +} + +/*! ZSTD_readSkippableFrame() : + * Retrieves content of a skippable frame, and writes it to dst buffer. + * + * The parameter magicVariant will receive the magicVariant that was supplied when the frame was written, + * i.e. magicNumber - ZSTD_MAGIC_SKIPPABLE_START. This can be NULL if the caller is not interested + * in the magicVariant. + * + * Returns an error if destination buffer is not large enough, or if this is not a valid skippable frame. + * + * @return : number of bytes written or a ZSTD error. + */ +size_t ZSTD_readSkippableFrame(void* dst, size_t dstCapacity, + unsigned* magicVariant, /* optional, can be NULL */ + const void* src, size_t srcSize) +{ + RETURN_ERROR_IF(srcSize < ZSTD_SKIPPABLEHEADERSIZE, srcSize_wrong, ""); + + { U32 const magicNumber = MEM_readLE32(src); + size_t skippableFrameSize = readSkippableFrameSize(src, srcSize); + size_t skippableContentSize = skippableFrameSize - ZSTD_SKIPPABLEHEADERSIZE; + + /* check input validity */ + RETURN_ERROR_IF(!ZSTD_isSkippableFrame(src, srcSize), frameParameter_unsupported, ""); + RETURN_ERROR_IF(skippableFrameSize < ZSTD_SKIPPABLEHEADERSIZE || skippableFrameSize > srcSize, srcSize_wrong, ""); + RETURN_ERROR_IF(skippableContentSize > dstCapacity, dstSize_tooSmall, ""); + + /* deliver payload */ + if (skippableContentSize > 0 && dst != NULL) + ZSTD_memcpy(dst, (const BYTE *)src + ZSTD_SKIPPABLEHEADERSIZE, skippableContentSize); + if (magicVariant != NULL) + *magicVariant = magicNumber - ZSTD_MAGIC_SKIPPABLE_START; + return skippableContentSize; + } +} + +/** ZSTD_findDecompressedSize() : + * `srcSize` must be the exact length of some number of ZSTD compressed and/or + * skippable frames + * note: compatible with legacy mode + * @return : decompressed size of the frames contained */ +unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize) +{ + unsigned long long totalDstSize = 0; + + while (srcSize >= ZSTD_startingInputLength(ZSTD_f_zstd1)) { + U32 const magicNumber = MEM_readLE32(src); + + if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { + size_t const skippableSize = readSkippableFrameSize(src, srcSize); + if (ZSTD_isError(skippableSize)) return ZSTD_CONTENTSIZE_ERROR; + assert(skippableSize <= srcSize); + + src = (const BYTE *)src + skippableSize; + srcSize -= skippableSize; + continue; + } + + { unsigned long long const fcs = ZSTD_getFrameContentSize(src, srcSize); + if (fcs >= ZSTD_CONTENTSIZE_ERROR) return fcs; + + if (totalDstSize + fcs < totalDstSize) + return ZSTD_CONTENTSIZE_ERROR; /* check for overflow */ + totalDstSize += fcs; + } + /* skip to next frame */ + { size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize); + if (ZSTD_isError(frameSrcSize)) return ZSTD_CONTENTSIZE_ERROR; + assert(frameSrcSize <= srcSize); + + src = (const BYTE *)src + frameSrcSize; + srcSize -= frameSrcSize; + } + } /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */ + + if (srcSize) return ZSTD_CONTENTSIZE_ERROR; + + return totalDstSize; +} + +/** ZSTD_getDecompressedSize() : + * compatible with legacy mode + * @return : decompressed size if known, 0 otherwise + note : 0 can mean any of the following : + - frame content is empty + - decompressed size field is not present in frame header + - frame header unknown / not supported + - frame header not complete (`srcSize` too small) */ +unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize) +{ + unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize); + ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_ERROR < ZSTD_CONTENTSIZE_UNKNOWN); + return (ret >= ZSTD_CONTENTSIZE_ERROR) ? 0 : ret; +} + + +/** ZSTD_decodeFrameHeader() : + * `headerSize` must be the size provided by ZSTD_frameHeaderSize(). + * If multiple DDict references are enabled, also will choose the correct DDict to use. + * @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */ +static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t headerSize) +{ + size_t const result = ZSTD_getFrameHeader_advanced(&(dctx->fParams), src, headerSize, dctx->format); + if (ZSTD_isError(result)) return result; /* invalid header */ + RETURN_ERROR_IF(result>0, srcSize_wrong, "headerSize too small"); + + /* Reference DDict requested by frame if dctx references multiple ddicts */ + if (dctx->refMultipleDDicts == ZSTD_rmd_refMultipleDDicts && dctx->ddictSet) { + ZSTD_DCtx_selectFrameDDict(dctx); + } + +#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + /* Skip the dictID check in fuzzing mode, because it makes the search + * harder. + */ + RETURN_ERROR_IF(dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID), + dictionary_wrong, ""); +#endif + dctx->validateChecksum = (dctx->fParams.checksumFlag && !dctx->forceIgnoreChecksum) ? 1 : 0; + if (dctx->validateChecksum) XXH64_reset(&dctx->xxhState, 0); + dctx->processedCSize += headerSize; + return 0; +} + +static ZSTD_frameSizeInfo ZSTD_errorFrameSizeInfo(size_t ret) +{ + ZSTD_frameSizeInfo frameSizeInfo; + frameSizeInfo.compressedSize = ret; + frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR; + return frameSizeInfo; +} + +static ZSTD_frameSizeInfo ZSTD_findFrameSizeInfo(const void* src, size_t srcSize, ZSTD_format_e format) +{ + ZSTD_frameSizeInfo frameSizeInfo; + ZSTD_memset(&frameSizeInfo, 0, sizeof(ZSTD_frameSizeInfo)); + +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (format == ZSTD_f_zstd1 && ZSTD_isLegacy(src, srcSize)) + return ZSTD_findFrameSizeInfoLegacy(src, srcSize); +#endif + + if (format == ZSTD_f_zstd1 && (srcSize >= ZSTD_SKIPPABLEHEADERSIZE) + && (MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { + frameSizeInfo.compressedSize = readSkippableFrameSize(src, srcSize); + assert(ZSTD_isError(frameSizeInfo.compressedSize) || + frameSizeInfo.compressedSize <= srcSize); + return frameSizeInfo; + } else { + const BYTE* ip = (const BYTE*)src; + const BYTE* const ipstart = ip; + size_t remainingSize = srcSize; + size_t nbBlocks = 0; + ZSTD_frameHeader zfh; + + /* Extract Frame Header */ + { size_t const ret = ZSTD_getFrameHeader_advanced(&zfh, src, srcSize, format); + if (ZSTD_isError(ret)) + return ZSTD_errorFrameSizeInfo(ret); + if (ret > 0) + return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong)); + } + + ip += zfh.headerSize; + remainingSize -= zfh.headerSize; + + /* Iterate over each block */ + while (1) { + blockProperties_t blockProperties; + size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties); + if (ZSTD_isError(cBlockSize)) + return ZSTD_errorFrameSizeInfo(cBlockSize); + + if (ZSTD_blockHeaderSize + cBlockSize > remainingSize) + return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong)); + + ip += ZSTD_blockHeaderSize + cBlockSize; + remainingSize -= ZSTD_blockHeaderSize + cBlockSize; + nbBlocks++; + + if (blockProperties.lastBlock) break; + } + + /* Final frame content checksum */ + if (zfh.checksumFlag) { + if (remainingSize < 4) + return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong)); + ip += 4; + } + + frameSizeInfo.nbBlocks = nbBlocks; + frameSizeInfo.compressedSize = (size_t)(ip - ipstart); + frameSizeInfo.decompressedBound = (zfh.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) + ? zfh.frameContentSize + : (unsigned long long)nbBlocks * zfh.blockSizeMax; + return frameSizeInfo; + } +} + +static size_t ZSTD_findFrameCompressedSize_advanced(const void *src, size_t srcSize, ZSTD_format_e format) { + ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize, format); + return frameSizeInfo.compressedSize; +} + +/** ZSTD_findFrameCompressedSize() : + * See docs in zstd.h + * Note: compatible with legacy mode */ +size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize) +{ + return ZSTD_findFrameCompressedSize_advanced(src, srcSize, ZSTD_f_zstd1); +} + +/** ZSTD_decompressBound() : + * compatible with legacy mode + * `src` must point to the start of a ZSTD frame or a skippeable frame + * `srcSize` must be at least as large as the frame contained + * @return : the maximum decompressed size of the compressed source + */ +unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize) +{ + unsigned long long bound = 0; + /* Iterate over each frame */ + while (srcSize > 0) { + ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize, ZSTD_f_zstd1); + size_t const compressedSize = frameSizeInfo.compressedSize; + unsigned long long const decompressedBound = frameSizeInfo.decompressedBound; + if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR) + return ZSTD_CONTENTSIZE_ERROR; + assert(srcSize >= compressedSize); + src = (const BYTE*)src + compressedSize; + srcSize -= compressedSize; + bound += decompressedBound; + } + return bound; +} + +size_t ZSTD_decompressionMargin(void const* src, size_t srcSize) +{ + size_t margin = 0; + unsigned maxBlockSize = 0; + + /* Iterate over each frame */ + while (srcSize > 0) { + ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize, ZSTD_f_zstd1); + size_t const compressedSize = frameSizeInfo.compressedSize; + unsigned long long const decompressedBound = frameSizeInfo.decompressedBound; + ZSTD_frameHeader zfh; + + FORWARD_IF_ERROR(ZSTD_getFrameHeader(&zfh, src, srcSize), ""); + if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR) + return ERROR(corruption_detected); + + if (zfh.frameType == ZSTD_frame) { + /* Add the frame header to our margin */ + margin += zfh.headerSize; + /* Add the checksum to our margin */ + margin += zfh.checksumFlag ? 4 : 0; + /* Add 3 bytes per block */ + margin += 3 * frameSizeInfo.nbBlocks; + + /* Compute the max block size */ + maxBlockSize = MAX(maxBlockSize, zfh.blockSizeMax); + } else { + assert(zfh.frameType == ZSTD_skippableFrame); + /* Add the entire skippable frame size to our margin. */ + margin += compressedSize; + } + + assert(srcSize >= compressedSize); + src = (const BYTE*)src + compressedSize; + srcSize -= compressedSize; + } + + /* Add the max block size back to the margin. */ + margin += maxBlockSize; + + return margin; +} + +/*-************************************************************* + * Frame decoding + ***************************************************************/ + +/** ZSTD_insertBlock() : + * insert `src` block into `dctx` history. Useful to track uncompressed blocks. */ +size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize) +{ + DEBUGLOG(5, "ZSTD_insertBlock: %u bytes", (unsigned)blockSize); + ZSTD_checkContinuity(dctx, blockStart, blockSize); + dctx->previousDstEnd = (const char*)blockStart + blockSize; + return blockSize; +} + + +static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity, + const void* src, size_t srcSize) +{ + DEBUGLOG(5, "ZSTD_copyRawBlock"); + RETURN_ERROR_IF(srcSize > dstCapacity, dstSize_tooSmall, ""); + if (dst == NULL) { + if (srcSize == 0) return 0; + RETURN_ERROR(dstBuffer_null, ""); + } + ZSTD_memmove(dst, src, srcSize); + return srcSize; +} + +static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity, + BYTE b, + size_t regenSize) +{ + RETURN_ERROR_IF(regenSize > dstCapacity, dstSize_tooSmall, ""); + if (dst == NULL) { + if (regenSize == 0) return 0; + RETURN_ERROR(dstBuffer_null, ""); + } + ZSTD_memset(dst, b, regenSize); + return regenSize; +} + +static void ZSTD_DCtx_trace_end(ZSTD_DCtx const* dctx, U64 uncompressedSize, U64 compressedSize, unsigned streaming) +{ +#if ZSTD_TRACE + if (dctx->traceCtx && ZSTD_trace_decompress_end != NULL) { + ZSTD_Trace trace; + ZSTD_memset(&trace, 0, sizeof(trace)); + trace.version = ZSTD_VERSION_NUMBER; + trace.streaming = streaming; + if (dctx->ddict) { + trace.dictionaryID = ZSTD_getDictID_fromDDict(dctx->ddict); + trace.dictionarySize = ZSTD_DDict_dictSize(dctx->ddict); + trace.dictionaryIsCold = dctx->ddictIsCold; + } + trace.uncompressedSize = (size_t)uncompressedSize; + trace.compressedSize = (size_t)compressedSize; + trace.dctx = dctx; + ZSTD_trace_decompress_end(dctx->traceCtx, &trace); + } +#else + (void)dctx; + (void)uncompressedSize; + (void)compressedSize; + (void)streaming; +#endif +} + + +/*! ZSTD_decompressFrame() : + * @dctx must be properly initialized + * will update *srcPtr and *srcSizePtr, + * to make *srcPtr progress by one frame. */ +static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void** srcPtr, size_t *srcSizePtr) +{ + const BYTE* const istart = (const BYTE*)(*srcPtr); + const BYTE* ip = istart; + BYTE* const ostart = (BYTE*)dst; + BYTE* const oend = dstCapacity != 0 ? ostart + dstCapacity : ostart; + BYTE* op = ostart; + size_t remainingSrcSize = *srcSizePtr; + + DEBUGLOG(4, "ZSTD_decompressFrame (srcSize:%i)", (int)*srcSizePtr); + + /* check */ + RETURN_ERROR_IF( + remainingSrcSize < ZSTD_FRAMEHEADERSIZE_MIN(dctx->format)+ZSTD_blockHeaderSize, + srcSize_wrong, ""); + + /* Frame Header */ + { size_t const frameHeaderSize = ZSTD_frameHeaderSize_internal( + ip, ZSTD_FRAMEHEADERSIZE_PREFIX(dctx->format), dctx->format); + if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize; + RETURN_ERROR_IF(remainingSrcSize < frameHeaderSize+ZSTD_blockHeaderSize, + srcSize_wrong, ""); + FORWARD_IF_ERROR( ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize) , ""); + ip += frameHeaderSize; remainingSrcSize -= frameHeaderSize; + } + + /* Shrink the blockSizeMax if enabled */ + if (dctx->maxBlockSizeParam != 0) + dctx->fParams.blockSizeMax = MIN(dctx->fParams.blockSizeMax, (unsigned)dctx->maxBlockSizeParam); + + /* Loop on each block */ + while (1) { + BYTE* oBlockEnd = oend; + size_t decodedSize; + blockProperties_t blockProperties; + size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSrcSize, &blockProperties); + if (ZSTD_isError(cBlockSize)) return cBlockSize; + + ip += ZSTD_blockHeaderSize; + remainingSrcSize -= ZSTD_blockHeaderSize; + RETURN_ERROR_IF(cBlockSize > remainingSrcSize, srcSize_wrong, ""); + + if (ip >= op && ip < oBlockEnd) { + /* We are decompressing in-place. Limit the output pointer so that we + * don't overwrite the block that we are currently reading. This will + * fail decompression if the input & output pointers aren't spaced + * far enough apart. + * + * This is important to set, even when the pointers are far enough + * apart, because ZSTD_decompressBlock_internal() can decide to store + * literals in the output buffer, after the block it is decompressing. + * Since we don't want anything to overwrite our input, we have to tell + * ZSTD_decompressBlock_internal to never write past ip. + * + * See ZSTD_allocateLiteralsBuffer() for reference. + */ + oBlockEnd = op + (ip - op); + } + + switch(blockProperties.blockType) + { + case bt_compressed: + assert(dctx->isFrameDecompression == 1); + decodedSize = ZSTD_decompressBlock_internal(dctx, op, (size_t)(oBlockEnd-op), ip, cBlockSize, not_streaming); + break; + case bt_raw : + /* Use oend instead of oBlockEnd because this function is safe to overlap. It uses memmove. */ + decodedSize = ZSTD_copyRawBlock(op, (size_t)(oend-op), ip, cBlockSize); + break; + case bt_rle : + decodedSize = ZSTD_setRleBlock(op, (size_t)(oBlockEnd-op), *ip, blockProperties.origSize); + break; + case bt_reserved : + default: + RETURN_ERROR(corruption_detected, "invalid block type"); + } + FORWARD_IF_ERROR(decodedSize, "Block decompression failure"); + DEBUGLOG(5, "Decompressed block of dSize = %u", (unsigned)decodedSize); + if (dctx->validateChecksum) { + XXH64_update(&dctx->xxhState, op, decodedSize); + } + if (decodedSize) /* support dst = NULL,0 */ { + op += decodedSize; + } + assert(ip != NULL); + ip += cBlockSize; + remainingSrcSize -= cBlockSize; + if (blockProperties.lastBlock) break; + } + + if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) { + RETURN_ERROR_IF((U64)(op-ostart) != dctx->fParams.frameContentSize, + corruption_detected, ""); + } + if (dctx->fParams.checksumFlag) { /* Frame content checksum verification */ + RETURN_ERROR_IF(remainingSrcSize<4, checksum_wrong, ""); + if (!dctx->forceIgnoreChecksum) { + U32 const checkCalc = (U32)XXH64_digest(&dctx->xxhState); + U32 checkRead; + checkRead = MEM_readLE32(ip); + RETURN_ERROR_IF(checkRead != checkCalc, checksum_wrong, ""); + } + ip += 4; + remainingSrcSize -= 4; + } + ZSTD_DCtx_trace_end(dctx, (U64)(op-ostart), (U64)(ip-istart), /* streaming */ 0); + /* Allow caller to get size read */ + DEBUGLOG(4, "ZSTD_decompressFrame: decompressed frame of size %zi, consuming %zi bytes of input", op-ostart, ip - (const BYTE*)*srcPtr); + *srcPtr = ip; + *srcSizePtr = remainingSrcSize; + return (size_t)(op-ostart); +} + +static +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, + const void* dict, size_t dictSize, + const ZSTD_DDict* ddict) +{ + void* const dststart = dst; + int moreThan1Frame = 0; + + DEBUGLOG(5, "ZSTD_decompressMultiFrame"); + assert(dict==NULL || ddict==NULL); /* either dict or ddict set, not both */ + + if (ddict) { + dict = ZSTD_DDict_dictContent(ddict); + dictSize = ZSTD_DDict_dictSize(ddict); + } + + while (srcSize >= ZSTD_startingInputLength(dctx->format)) { + +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (dctx->format == ZSTD_f_zstd1 && ZSTD_isLegacy(src, srcSize)) { + size_t decodedSize; + size_t const frameSize = ZSTD_findFrameCompressedSizeLegacy(src, srcSize); + if (ZSTD_isError(frameSize)) return frameSize; + RETURN_ERROR_IF(dctx->staticSize, memory_allocation, + "legacy support is not compatible with static dctx"); + + decodedSize = ZSTD_decompressLegacy(dst, dstCapacity, src, frameSize, dict, dictSize); + if (ZSTD_isError(decodedSize)) return decodedSize; + + { + unsigned long long const expectedSize = ZSTD_getFrameContentSize(src, srcSize); + RETURN_ERROR_IF(expectedSize == ZSTD_CONTENTSIZE_ERROR, corruption_detected, "Corrupted frame header!"); + if (expectedSize != ZSTD_CONTENTSIZE_UNKNOWN) { + RETURN_ERROR_IF(expectedSize != decodedSize, corruption_detected, + "Frame header size does not match decoded size!"); + } + } + + assert(decodedSize <= dstCapacity); + dst = (BYTE*)dst + decodedSize; + dstCapacity -= decodedSize; + + src = (const BYTE*)src + frameSize; + srcSize -= frameSize; + + continue; + } +#endif + + if (dctx->format == ZSTD_f_zstd1 && srcSize >= 4) { + U32 const magicNumber = MEM_readLE32(src); + DEBUGLOG(5, "reading magic number %08X", (unsigned)magicNumber); + if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { + /* skippable frame detected : skip it */ + size_t const skippableSize = readSkippableFrameSize(src, srcSize); + FORWARD_IF_ERROR(skippableSize, "invalid skippable frame"); + assert(skippableSize <= srcSize); + + src = (const BYTE *)src + skippableSize; + srcSize -= skippableSize; + continue; /* check next frame */ + } } + + if (ddict) { + /* we were called from ZSTD_decompress_usingDDict */ + FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(dctx, ddict), ""); + } else { + /* this will initialize correctly with no dict if dict == NULL, so + * use this in all cases but ddict */ + FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize), ""); + } + ZSTD_checkContinuity(dctx, dst, dstCapacity); + + { const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity, + &src, &srcSize); + RETURN_ERROR_IF( + (ZSTD_getErrorCode(res) == ZSTD_error_prefix_unknown) + && (moreThan1Frame==1), + srcSize_wrong, + "At least one frame successfully completed, " + "but following bytes are garbage: " + "it's more likely to be a srcSize error, " + "specifying more input bytes than size of frame(s). " + "Note: one could be unlucky, it might be a corruption error instead, " + "happening right at the place where we expect zstd magic bytes. " + "But this is _much_ less likely than a srcSize field error."); + if (ZSTD_isError(res)) return res; + assert(res <= dstCapacity); + if (res != 0) + dst = (BYTE*)dst + res; + dstCapacity -= res; + } + moreThan1Frame = 1; + } /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */ + + RETURN_ERROR_IF(srcSize, srcSize_wrong, "input not entirely consumed"); + + return (size_t)((BYTE*)dst - (BYTE*)dststart); +} + +size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, + const void* dict, size_t dictSize) +{ + return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, dict, dictSize, NULL); +} + + +static ZSTD_DDict const* ZSTD_getDDict(ZSTD_DCtx* dctx) +{ + switch (dctx->dictUses) { + default: + assert(0 /* Impossible */); + ZSTD_FALLTHROUGH; + case ZSTD_dont_use: + ZSTD_clearDict(dctx); + return NULL; + case ZSTD_use_indefinitely: + return dctx->ddict; + case ZSTD_use_once: + dctx->dictUses = ZSTD_dont_use; + return dctx->ddict; + } +} + +size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize) +{ + return ZSTD_decompress_usingDDict(dctx, dst, dstCapacity, src, srcSize, ZSTD_getDDict(dctx)); +} + + +size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize) +{ +#if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE>=1) + size_t regenSize; + ZSTD_DCtx* const dctx = ZSTD_createDCtx_internal(ZSTD_defaultCMem); + RETURN_ERROR_IF(dctx==NULL, memory_allocation, "NULL pointer!"); + regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize); + ZSTD_freeDCtx(dctx); + return regenSize; +#else /* stack mode */ + ZSTD_DCtx dctx; + ZSTD_initDCtx_internal(&dctx); + return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize); +#endif +} + + +/*-************************************** +* Advanced Streaming Decompression API +* Bufferless and synchronous +****************************************/ +size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; } + +/** + * Similar to ZSTD_nextSrcSizeToDecompress(), but when a block input can be streamed, we + * allow taking a partial block as the input. Currently only raw uncompressed blocks can + * be streamed. + * + * For blocks that can be streamed, this allows us to reduce the latency until we produce + * output, and avoid copying the input. + * + * @param inputSize - The total amount of input that the caller currently has. + */ +static size_t ZSTD_nextSrcSizeToDecompressWithInputSize(ZSTD_DCtx* dctx, size_t inputSize) { + if (!(dctx->stage == ZSTDds_decompressBlock || dctx->stage == ZSTDds_decompressLastBlock)) + return dctx->expected; + if (dctx->bType != bt_raw) + return dctx->expected; + return BOUNDED(1, inputSize, dctx->expected); +} + +ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) { + switch(dctx->stage) + { + default: /* should not happen */ + assert(0); + ZSTD_FALLTHROUGH; + case ZSTDds_getFrameHeaderSize: + ZSTD_FALLTHROUGH; + case ZSTDds_decodeFrameHeader: + return ZSTDnit_frameHeader; + case ZSTDds_decodeBlockHeader: + return ZSTDnit_blockHeader; + case ZSTDds_decompressBlock: + return ZSTDnit_block; + case ZSTDds_decompressLastBlock: + return ZSTDnit_lastBlock; + case ZSTDds_checkChecksum: + return ZSTDnit_checksum; + case ZSTDds_decodeSkippableHeader: + ZSTD_FALLTHROUGH; + case ZSTDds_skipFrame: + return ZSTDnit_skippableFrame; + } +} + +static int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; } + +/** ZSTD_decompressContinue() : + * srcSize : must be the exact nb of bytes expected (see ZSTD_nextSrcSizeToDecompress()) + * @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity) + * or an error code, which can be tested using ZSTD_isError() */ +size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize) +{ + DEBUGLOG(5, "ZSTD_decompressContinue (srcSize:%u)", (unsigned)srcSize); + /* Sanity check */ + RETURN_ERROR_IF(srcSize != ZSTD_nextSrcSizeToDecompressWithInputSize(dctx, srcSize), srcSize_wrong, "not allowed"); + ZSTD_checkContinuity(dctx, dst, dstCapacity); + + dctx->processedCSize += srcSize; + + switch (dctx->stage) + { + case ZSTDds_getFrameHeaderSize : + assert(src != NULL); + if (dctx->format == ZSTD_f_zstd1) { /* allows header */ + assert(srcSize >= ZSTD_FRAMEIDSIZE); /* to read skippable magic number */ + if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */ + ZSTD_memcpy(dctx->headerBuffer, src, srcSize); + dctx->expected = ZSTD_SKIPPABLEHEADERSIZE - srcSize; /* remaining to load to get full skippable frame header */ + dctx->stage = ZSTDds_decodeSkippableHeader; + return 0; + } } + dctx->headerSize = ZSTD_frameHeaderSize_internal(src, srcSize, dctx->format); + if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize; + ZSTD_memcpy(dctx->headerBuffer, src, srcSize); + dctx->expected = dctx->headerSize - srcSize; + dctx->stage = ZSTDds_decodeFrameHeader; + return 0; + + case ZSTDds_decodeFrameHeader: + assert(src != NULL); + ZSTD_memcpy(dctx->headerBuffer + (dctx->headerSize - srcSize), src, srcSize); + FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize), ""); + dctx->expected = ZSTD_blockHeaderSize; + dctx->stage = ZSTDds_decodeBlockHeader; + return 0; + + case ZSTDds_decodeBlockHeader: + { blockProperties_t bp; + size_t const cBlockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp); + if (ZSTD_isError(cBlockSize)) return cBlockSize; + RETURN_ERROR_IF(cBlockSize > dctx->fParams.blockSizeMax, corruption_detected, "Block Size Exceeds Maximum"); + dctx->expected = cBlockSize; + dctx->bType = bp.blockType; + dctx->rleSize = bp.origSize; + if (cBlockSize) { + dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock; + return 0; + } + /* empty block */ + if (bp.lastBlock) { + if (dctx->fParams.checksumFlag) { + dctx->expected = 4; + dctx->stage = ZSTDds_checkChecksum; + } else { + dctx->expected = 0; /* end of frame */ + dctx->stage = ZSTDds_getFrameHeaderSize; + } + } else { + dctx->expected = ZSTD_blockHeaderSize; /* jump to next header */ + dctx->stage = ZSTDds_decodeBlockHeader; + } + return 0; + } + + case ZSTDds_decompressLastBlock: + case ZSTDds_decompressBlock: + DEBUGLOG(5, "ZSTD_decompressContinue: case ZSTDds_decompressBlock"); + { size_t rSize; + switch(dctx->bType) + { + case bt_compressed: + DEBUGLOG(5, "ZSTD_decompressContinue: case bt_compressed"); + assert(dctx->isFrameDecompression == 1); + rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, is_streaming); + dctx->expected = 0; /* Streaming not supported */ + break; + case bt_raw : + assert(srcSize <= dctx->expected); + rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize); + FORWARD_IF_ERROR(rSize, "ZSTD_copyRawBlock failed"); + assert(rSize == srcSize); + dctx->expected -= rSize; + break; + case bt_rle : + rSize = ZSTD_setRleBlock(dst, dstCapacity, *(const BYTE*)src, dctx->rleSize); + dctx->expected = 0; /* Streaming not supported */ + break; + case bt_reserved : /* should never happen */ + default: + RETURN_ERROR(corruption_detected, "invalid block type"); + } + FORWARD_IF_ERROR(rSize, ""); + RETURN_ERROR_IF(rSize > dctx->fParams.blockSizeMax, corruption_detected, "Decompressed Block Size Exceeds Maximum"); + DEBUGLOG(5, "ZSTD_decompressContinue: decoded size from block : %u", (unsigned)rSize); + dctx->decodedSize += rSize; + if (dctx->validateChecksum) XXH64_update(&dctx->xxhState, dst, rSize); + dctx->previousDstEnd = (char*)dst + rSize; + + /* Stay on the same stage until we are finished streaming the block. */ + if (dctx->expected > 0) { + return rSize; + } + + if (dctx->stage == ZSTDds_decompressLastBlock) { /* end of frame */ + DEBUGLOG(4, "ZSTD_decompressContinue: decoded size from frame : %u", (unsigned)dctx->decodedSize); + RETURN_ERROR_IF( + dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN + && dctx->decodedSize != dctx->fParams.frameContentSize, + corruption_detected, ""); + if (dctx->fParams.checksumFlag) { /* another round for frame checksum */ + dctx->expected = 4; + dctx->stage = ZSTDds_checkChecksum; + } else { + ZSTD_DCtx_trace_end(dctx, dctx->decodedSize, dctx->processedCSize, /* streaming */ 1); + dctx->expected = 0; /* ends here */ + dctx->stage = ZSTDds_getFrameHeaderSize; + } + } else { + dctx->stage = ZSTDds_decodeBlockHeader; + dctx->expected = ZSTD_blockHeaderSize; + } + return rSize; + } + + case ZSTDds_checkChecksum: + assert(srcSize == 4); /* guaranteed by dctx->expected */ + { + if (dctx->validateChecksum) { + U32 const h32 = (U32)XXH64_digest(&dctx->xxhState); + U32 const check32 = MEM_readLE32(src); + DEBUGLOG(4, "ZSTD_decompressContinue: checksum : calculated %08X :: %08X read", (unsigned)h32, (unsigned)check32); + RETURN_ERROR_IF(check32 != h32, checksum_wrong, ""); + } + ZSTD_DCtx_trace_end(dctx, dctx->decodedSize, dctx->processedCSize, /* streaming */ 1); + dctx->expected = 0; + dctx->stage = ZSTDds_getFrameHeaderSize; + return 0; + } + + case ZSTDds_decodeSkippableHeader: + assert(src != NULL); + assert(srcSize <= ZSTD_SKIPPABLEHEADERSIZE); + assert(dctx->format != ZSTD_f_zstd1_magicless); + ZSTD_memcpy(dctx->headerBuffer + (ZSTD_SKIPPABLEHEADERSIZE - srcSize), src, srcSize); /* complete skippable header */ + dctx->expected = MEM_readLE32(dctx->headerBuffer + ZSTD_FRAMEIDSIZE); /* note : dctx->expected can grow seriously large, beyond local buffer size */ + dctx->stage = ZSTDds_skipFrame; + return 0; + + case ZSTDds_skipFrame: + dctx->expected = 0; + dctx->stage = ZSTDds_getFrameHeaderSize; + return 0; + + default: + assert(0); /* impossible */ + RETURN_ERROR(GENERIC, "impossible to reach"); /* some compilers require default to do something */ + } +} + + +static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) +{ + dctx->dictEnd = dctx->previousDstEnd; + dctx->virtualStart = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart)); + dctx->prefixStart = dict; + dctx->previousDstEnd = (const char*)dict + dictSize; +#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + dctx->dictContentBeginForFuzzing = dctx->prefixStart; + dctx->dictContentEndForFuzzing = dctx->previousDstEnd; +#endif + return 0; +} + +/*! ZSTD_loadDEntropy() : + * dict : must point at beginning of a valid zstd dictionary. + * @return : size of entropy tables read */ +size_t +ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy, + const void* const dict, size_t const dictSize) +{ + const BYTE* dictPtr = (const BYTE*)dict; + const BYTE* const dictEnd = dictPtr + dictSize; + + RETURN_ERROR_IF(dictSize <= 8, dictionary_corrupted, "dict is too small"); + assert(MEM_readLE32(dict) == ZSTD_MAGIC_DICTIONARY); /* dict must be valid */ + dictPtr += 8; /* skip header = magic + dictID */ + + ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, OFTable) == offsetof(ZSTD_entropyDTables_t, LLTable) + sizeof(entropy->LLTable)); + ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, MLTable) == offsetof(ZSTD_entropyDTables_t, OFTable) + sizeof(entropy->OFTable)); + ZSTD_STATIC_ASSERT(sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable) >= HUF_DECOMPRESS_WORKSPACE_SIZE); + { void* const workspace = &entropy->LLTable; /* use fse tables as temporary workspace; implies fse tables are grouped together */ + size_t const workspaceSize = sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable); +#ifdef HUF_FORCE_DECOMPRESS_X1 + /* in minimal huffman, we always use X1 variants */ + size_t const hSize = HUF_readDTableX1_wksp(entropy->hufTable, + dictPtr, dictEnd - dictPtr, + workspace, workspaceSize, /* flags */ 0); +#else + size_t const hSize = HUF_readDTableX2_wksp(entropy->hufTable, + dictPtr, (size_t)(dictEnd - dictPtr), + workspace, workspaceSize, /* flags */ 0); +#endif + RETURN_ERROR_IF(HUF_isError(hSize), dictionary_corrupted, ""); + dictPtr += hSize; + } + + { short offcodeNCount[MaxOff+1]; + unsigned offcodeMaxValue = MaxOff, offcodeLog; + size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, (size_t)(dictEnd-dictPtr)); + RETURN_ERROR_IF(FSE_isError(offcodeHeaderSize), dictionary_corrupted, ""); + RETURN_ERROR_IF(offcodeMaxValue > MaxOff, dictionary_corrupted, ""); + RETURN_ERROR_IF(offcodeLog > OffFSELog, dictionary_corrupted, ""); + ZSTD_buildFSETable( entropy->OFTable, + offcodeNCount, offcodeMaxValue, + OF_base, OF_bits, + offcodeLog, + entropy->workspace, sizeof(entropy->workspace), + /* bmi2 */0); + dictPtr += offcodeHeaderSize; + } + + { short matchlengthNCount[MaxML+1]; + unsigned matchlengthMaxValue = MaxML, matchlengthLog; + size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, (size_t)(dictEnd-dictPtr)); + RETURN_ERROR_IF(FSE_isError(matchlengthHeaderSize), dictionary_corrupted, ""); + RETURN_ERROR_IF(matchlengthMaxValue > MaxML, dictionary_corrupted, ""); + RETURN_ERROR_IF(matchlengthLog > MLFSELog, dictionary_corrupted, ""); + ZSTD_buildFSETable( entropy->MLTable, + matchlengthNCount, matchlengthMaxValue, + ML_base, ML_bits, + matchlengthLog, + entropy->workspace, sizeof(entropy->workspace), + /* bmi2 */ 0); + dictPtr += matchlengthHeaderSize; + } + + { short litlengthNCount[MaxLL+1]; + unsigned litlengthMaxValue = MaxLL, litlengthLog; + size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, (size_t)(dictEnd-dictPtr)); + RETURN_ERROR_IF(FSE_isError(litlengthHeaderSize), dictionary_corrupted, ""); + RETURN_ERROR_IF(litlengthMaxValue > MaxLL, dictionary_corrupted, ""); + RETURN_ERROR_IF(litlengthLog > LLFSELog, dictionary_corrupted, ""); + ZSTD_buildFSETable( entropy->LLTable, + litlengthNCount, litlengthMaxValue, + LL_base, LL_bits, + litlengthLog, + entropy->workspace, sizeof(entropy->workspace), + /* bmi2 */ 0); + dictPtr += litlengthHeaderSize; + } + + RETURN_ERROR_IF(dictPtr+12 > dictEnd, dictionary_corrupted, ""); + { int i; + size_t const dictContentSize = (size_t)(dictEnd - (dictPtr+12)); + for (i=0; i<3; i++) { + U32 const rep = MEM_readLE32(dictPtr); dictPtr += 4; + RETURN_ERROR_IF(rep==0 || rep > dictContentSize, + dictionary_corrupted, ""); + entropy->rep[i] = rep; + } } + + return (size_t)(dictPtr - (const BYTE*)dict); +} + +static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) +{ + if (dictSize < 8) return ZSTD_refDictContent(dctx, dict, dictSize); + { U32 const magic = MEM_readLE32(dict); + if (magic != ZSTD_MAGIC_DICTIONARY) { + return ZSTD_refDictContent(dctx, dict, dictSize); /* pure content mode */ + } } + dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE); + + /* load entropy tables */ + { size_t const eSize = ZSTD_loadDEntropy(&dctx->entropy, dict, dictSize); + RETURN_ERROR_IF(ZSTD_isError(eSize), dictionary_corrupted, ""); + dict = (const char*)dict + eSize; + dictSize -= eSize; + } + dctx->litEntropy = dctx->fseEntropy = 1; + + /* reference dictionary content */ + return ZSTD_refDictContent(dctx, dict, dictSize); +} + +size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx) +{ + assert(dctx != NULL); +#if ZSTD_TRACE + dctx->traceCtx = (ZSTD_trace_decompress_begin != NULL) ? ZSTD_trace_decompress_begin(dctx) : 0; +#endif + dctx->expected = ZSTD_startingInputLength(dctx->format); /* dctx->format must be properly set */ + dctx->stage = ZSTDds_getFrameHeaderSize; + dctx->processedCSize = 0; + dctx->decodedSize = 0; + dctx->previousDstEnd = NULL; + dctx->prefixStart = NULL; + dctx->virtualStart = NULL; + dctx->dictEnd = NULL; + dctx->entropy.hufTable[0] = (HUF_DTable)((ZSTD_HUFFDTABLE_CAPACITY_LOG)*0x1000001); /* cover both little and big endian */ + dctx->litEntropy = dctx->fseEntropy = 0; + dctx->dictID = 0; + dctx->bType = bt_reserved; + dctx->isFrameDecompression = 1; + ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue)); + ZSTD_memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue)); /* initial repcodes */ + dctx->LLTptr = dctx->entropy.LLTable; + dctx->MLTptr = dctx->entropy.MLTable; + dctx->OFTptr = dctx->entropy.OFTable; + dctx->HUFptr = dctx->entropy.hufTable; + return 0; +} + +size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) +{ + FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) , ""); + if (dict && dictSize) + RETURN_ERROR_IF( + ZSTD_isError(ZSTD_decompress_insertDictionary(dctx, dict, dictSize)), + dictionary_corrupted, ""); + return 0; +} + + +/* ====== ZSTD_DDict ====== */ + +size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict) +{ + DEBUGLOG(4, "ZSTD_decompressBegin_usingDDict"); + assert(dctx != NULL); + if (ddict) { + const char* const dictStart = (const char*)ZSTD_DDict_dictContent(ddict); + size_t const dictSize = ZSTD_DDict_dictSize(ddict); + const void* const dictEnd = dictStart + dictSize; + dctx->ddictIsCold = (dctx->dictEnd != dictEnd); + DEBUGLOG(4, "DDict is %s", + dctx->ddictIsCold ? "~cold~" : "hot!"); + } + FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) , ""); + if (ddict) { /* NULL ddict is equivalent to no dictionary */ + ZSTD_copyDDictParameters(dctx, ddict); + } + return 0; +} + +/*! ZSTD_getDictID_fromDict() : + * Provides the dictID stored within dictionary. + * if @return == 0, the dictionary is not conformant with Zstandard specification. + * It can still be loaded, but as a content-only dictionary. */ +unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize) +{ + if (dictSize < 8) return 0; + if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) return 0; + return MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE); +} + +/*! ZSTD_getDictID_fromFrame() : + * Provides the dictID required to decompress frame stored within `src`. + * If @return == 0, the dictID could not be decoded. + * This could for one of the following reasons : + * - The frame does not require a dictionary (most common case). + * - The frame was built with dictID intentionally removed. + * Needed dictionary is a hidden piece of information. + * Note : this use case also happens when using a non-conformant dictionary. + * - `srcSize` is too small, and as a result, frame header could not be decoded. + * Note : possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`. + * - This is not a Zstandard frame. + * When identifying the exact failure cause, it's possible to use + * ZSTD_getFrameHeader(), which will provide a more precise error code. */ +unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize) +{ + ZSTD_frameHeader zfp = { 0, 0, 0, ZSTD_frame, 0, 0, 0, 0, 0 }; + size_t const hError = ZSTD_getFrameHeader(&zfp, src, srcSize); + if (ZSTD_isError(hError)) return 0; + return zfp.dictID; +} + + +/*! ZSTD_decompress_usingDDict() : +* Decompression using a pre-digested Dictionary +* Use dictionary without significant overhead. */ +size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, + const ZSTD_DDict* ddict) +{ + /* pass content and size in case legacy frames are encountered */ + return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, + NULL, 0, + ddict); +} + + +/*===================================== +* Streaming decompression +*====================================*/ + +ZSTD_DStream* ZSTD_createDStream(void) +{ + DEBUGLOG(3, "ZSTD_createDStream"); + return ZSTD_createDCtx_internal(ZSTD_defaultCMem); +} + +ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize) +{ + return ZSTD_initStaticDCtx(workspace, workspaceSize); +} + +ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem) +{ + return ZSTD_createDCtx_internal(customMem); +} + +size_t ZSTD_freeDStream(ZSTD_DStream* zds) +{ + return ZSTD_freeDCtx(zds); +} + + +/* *** Initialization *** */ + +size_t ZSTD_DStreamInSize(void) { return ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize; } +size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_MAX; } + +size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, + const void* dict, size_t dictSize, + ZSTD_dictLoadMethod_e dictLoadMethod, + ZSTD_dictContentType_e dictContentType) +{ + RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, ""); + ZSTD_clearDict(dctx); + if (dict && dictSize != 0) { + dctx->ddictLocal = ZSTD_createDDict_advanced(dict, dictSize, dictLoadMethod, dictContentType, dctx->customMem); + RETURN_ERROR_IF(dctx->ddictLocal == NULL, memory_allocation, "NULL pointer!"); + dctx->ddict = dctx->ddictLocal; + dctx->dictUses = ZSTD_use_indefinitely; + } + return 0; +} + +size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) +{ + return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto); +} + +size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) +{ + return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto); +} + +size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType) +{ + FORWARD_IF_ERROR(ZSTD_DCtx_loadDictionary_advanced(dctx, prefix, prefixSize, ZSTD_dlm_byRef, dictContentType), ""); + dctx->dictUses = ZSTD_use_once; + return 0; +} + +size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize) +{ + return ZSTD_DCtx_refPrefix_advanced(dctx, prefix, prefixSize, ZSTD_dct_rawContent); +} + + +/* ZSTD_initDStream_usingDict() : + * return : expected size, aka ZSTD_startingInputLength(). + * this function cannot fail */ +size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize) +{ + DEBUGLOG(4, "ZSTD_initDStream_usingDict"); + FORWARD_IF_ERROR( ZSTD_DCtx_reset(zds, ZSTD_reset_session_only) , ""); + FORWARD_IF_ERROR( ZSTD_DCtx_loadDictionary(zds, dict, dictSize) , ""); + return ZSTD_startingInputLength(zds->format); +} + +/* note : this variant can't fail */ +size_t ZSTD_initDStream(ZSTD_DStream* zds) +{ + DEBUGLOG(4, "ZSTD_initDStream"); + FORWARD_IF_ERROR(ZSTD_DCtx_reset(zds, ZSTD_reset_session_only), ""); + FORWARD_IF_ERROR(ZSTD_DCtx_refDDict(zds, NULL), ""); + return ZSTD_startingInputLength(zds->format); +} + +/* ZSTD_initDStream_usingDDict() : + * ddict will just be referenced, and must outlive decompression session + * this function cannot fail */ +size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* dctx, const ZSTD_DDict* ddict) +{ + DEBUGLOG(4, "ZSTD_initDStream_usingDDict"); + FORWARD_IF_ERROR( ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only) , ""); + FORWARD_IF_ERROR( ZSTD_DCtx_refDDict(dctx, ddict) , ""); + return ZSTD_startingInputLength(dctx->format); +} + +/* ZSTD_resetDStream() : + * return : expected size, aka ZSTD_startingInputLength(). + * this function cannot fail */ +size_t ZSTD_resetDStream(ZSTD_DStream* dctx) +{ + DEBUGLOG(4, "ZSTD_resetDStream"); + FORWARD_IF_ERROR(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only), ""); + return ZSTD_startingInputLength(dctx->format); +} + + +size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict) +{ + RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, ""); + ZSTD_clearDict(dctx); + if (ddict) { + dctx->ddict = ddict; + dctx->dictUses = ZSTD_use_indefinitely; + if (dctx->refMultipleDDicts == ZSTD_rmd_refMultipleDDicts) { + if (dctx->ddictSet == NULL) { + dctx->ddictSet = ZSTD_createDDictHashSet(dctx->customMem); + if (!dctx->ddictSet) { + RETURN_ERROR(memory_allocation, "Failed to allocate memory for hash set!"); + } + } + assert(!dctx->staticSize); /* Impossible: ddictSet cannot have been allocated if static dctx */ + FORWARD_IF_ERROR(ZSTD_DDictHashSet_addDDict(dctx->ddictSet, ddict, dctx->customMem), ""); + } + } + return 0; +} + +/* ZSTD_DCtx_setMaxWindowSize() : + * note : no direct equivalence in ZSTD_DCtx_setParameter, + * since this version sets windowSize, and the other sets windowLog */ +size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize) +{ + ZSTD_bounds const bounds = ZSTD_dParam_getBounds(ZSTD_d_windowLogMax); + size_t const min = (size_t)1 << bounds.lowerBound; + size_t const max = (size_t)1 << bounds.upperBound; + RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, ""); + RETURN_ERROR_IF(maxWindowSize < min, parameter_outOfBound, ""); + RETURN_ERROR_IF(maxWindowSize > max, parameter_outOfBound, ""); + dctx->maxWindowSize = maxWindowSize; + return 0; +} + +size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format) +{ + return ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, (int)format); +} + +ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam) +{ + ZSTD_bounds bounds = { 0, 0, 0 }; + switch(dParam) { + case ZSTD_d_windowLogMax: + bounds.lowerBound = ZSTD_WINDOWLOG_ABSOLUTEMIN; + bounds.upperBound = ZSTD_WINDOWLOG_MAX; + return bounds; + case ZSTD_d_format: + bounds.lowerBound = (int)ZSTD_f_zstd1; + bounds.upperBound = (int)ZSTD_f_zstd1_magicless; + ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless); + return bounds; + case ZSTD_d_stableOutBuffer: + bounds.lowerBound = (int)ZSTD_bm_buffered; + bounds.upperBound = (int)ZSTD_bm_stable; + return bounds; + case ZSTD_d_forceIgnoreChecksum: + bounds.lowerBound = (int)ZSTD_d_validateChecksum; + bounds.upperBound = (int)ZSTD_d_ignoreChecksum; + return bounds; + case ZSTD_d_refMultipleDDicts: + bounds.lowerBound = (int)ZSTD_rmd_refSingleDDict; + bounds.upperBound = (int)ZSTD_rmd_refMultipleDDicts; + return bounds; + case ZSTD_d_disableHuffmanAssembly: + bounds.lowerBound = 0; + bounds.upperBound = 1; + return bounds; + case ZSTD_d_maxBlockSize: + bounds.lowerBound = ZSTD_BLOCKSIZE_MAX_MIN; + bounds.upperBound = ZSTD_BLOCKSIZE_MAX; + return bounds; + + default:; + } + bounds.error = ERROR(parameter_unsupported); + return bounds; +} + +/* ZSTD_dParam_withinBounds: + * @return 1 if value is within dParam bounds, + * 0 otherwise */ +static int ZSTD_dParam_withinBounds(ZSTD_dParameter dParam, int value) +{ + ZSTD_bounds const bounds = ZSTD_dParam_getBounds(dParam); + if (ZSTD_isError(bounds.error)) return 0; + if (value < bounds.lowerBound) return 0; + if (value > bounds.upperBound) return 0; + return 1; +} + +#define CHECK_DBOUNDS(p,v) { \ + RETURN_ERROR_IF(!ZSTD_dParam_withinBounds(p, v), parameter_outOfBound, ""); \ +} + +size_t ZSTD_DCtx_getParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int* value) +{ + switch (param) { + case ZSTD_d_windowLogMax: + *value = (int)ZSTD_highbit32((U32)dctx->maxWindowSize); + return 0; + case ZSTD_d_format: + *value = (int)dctx->format; + return 0; + case ZSTD_d_stableOutBuffer: + *value = (int)dctx->outBufferMode; + return 0; + case ZSTD_d_forceIgnoreChecksum: + *value = (int)dctx->forceIgnoreChecksum; + return 0; + case ZSTD_d_refMultipleDDicts: + *value = (int)dctx->refMultipleDDicts; + return 0; + case ZSTD_d_disableHuffmanAssembly: + *value = (int)dctx->disableHufAsm; + return 0; + case ZSTD_d_maxBlockSize: + *value = dctx->maxBlockSizeParam; + return 0; + default:; + } + RETURN_ERROR(parameter_unsupported, ""); +} + +size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter dParam, int value) +{ + RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, ""); + switch(dParam) { + case ZSTD_d_windowLogMax: + if (value == 0) value = ZSTD_WINDOWLOG_LIMIT_DEFAULT; + CHECK_DBOUNDS(ZSTD_d_windowLogMax, value); + dctx->maxWindowSize = ((size_t)1) << value; + return 0; + case ZSTD_d_format: + CHECK_DBOUNDS(ZSTD_d_format, value); + dctx->format = (ZSTD_format_e)value; + return 0; + case ZSTD_d_stableOutBuffer: + CHECK_DBOUNDS(ZSTD_d_stableOutBuffer, value); + dctx->outBufferMode = (ZSTD_bufferMode_e)value; + return 0; + case ZSTD_d_forceIgnoreChecksum: + CHECK_DBOUNDS(ZSTD_d_forceIgnoreChecksum, value); + dctx->forceIgnoreChecksum = (ZSTD_forceIgnoreChecksum_e)value; + return 0; + case ZSTD_d_refMultipleDDicts: + CHECK_DBOUNDS(ZSTD_d_refMultipleDDicts, value); + if (dctx->staticSize != 0) { + RETURN_ERROR(parameter_unsupported, "Static dctx does not support multiple DDicts!"); + } + dctx->refMultipleDDicts = (ZSTD_refMultipleDDicts_e)value; + return 0; + case ZSTD_d_disableHuffmanAssembly: + CHECK_DBOUNDS(ZSTD_d_disableHuffmanAssembly, value); + dctx->disableHufAsm = value != 0; + return 0; + case ZSTD_d_maxBlockSize: + if (value != 0) CHECK_DBOUNDS(ZSTD_d_maxBlockSize, value); + dctx->maxBlockSizeParam = value; + return 0; + default:; + } + RETURN_ERROR(parameter_unsupported, ""); +} + +size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset) +{ + if ( (reset == ZSTD_reset_session_only) + || (reset == ZSTD_reset_session_and_parameters) ) { + dctx->streamStage = zdss_init; + dctx->noForwardProgress = 0; + dctx->isFrameDecompression = 1; + } + if ( (reset == ZSTD_reset_parameters) + || (reset == ZSTD_reset_session_and_parameters) ) { + RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, ""); + ZSTD_clearDict(dctx); + ZSTD_DCtx_resetParameters(dctx); + } + return 0; +} + + +size_t ZSTD_sizeof_DStream(const ZSTD_DStream* dctx) +{ + return ZSTD_sizeof_DCtx(dctx); +} + +static size_t ZSTD_decodingBufferSize_internal(unsigned long long windowSize, unsigned long long frameContentSize, size_t blockSizeMax) +{ + size_t const blockSize = MIN((size_t)MIN(windowSize, ZSTD_BLOCKSIZE_MAX), blockSizeMax); + /* We need blockSize + WILDCOPY_OVERLENGTH worth of buffer so that if a block + * ends at windowSize + WILDCOPY_OVERLENGTH + 1 bytes, we can start writing + * the block at the beginning of the output buffer, and maintain a full window. + * + * We need another blockSize worth of buffer so that we can store split + * literals at the end of the block without overwriting the extDict window. + */ + unsigned long long const neededRBSize = windowSize + (blockSize * 2) + (WILDCOPY_OVERLENGTH * 2); + unsigned long long const neededSize = MIN(frameContentSize, neededRBSize); + size_t const minRBSize = (size_t) neededSize; + RETURN_ERROR_IF((unsigned long long)minRBSize != neededSize, + frameParameter_windowTooLarge, ""); + return minRBSize; +} + +size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize) +{ + return ZSTD_decodingBufferSize_internal(windowSize, frameContentSize, ZSTD_BLOCKSIZE_MAX); +} + +size_t ZSTD_estimateDStreamSize(size_t windowSize) +{ + size_t const blockSize = MIN(windowSize, ZSTD_BLOCKSIZE_MAX); + size_t const inBuffSize = blockSize; /* no block can be larger */ + size_t const outBuffSize = ZSTD_decodingBufferSize_min(windowSize, ZSTD_CONTENTSIZE_UNKNOWN); + return ZSTD_estimateDCtxSize() + inBuffSize + outBuffSize; +} + +size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize) +{ + U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX; /* note : should be user-selectable, but requires an additional parameter (or a dctx) */ + ZSTD_frameHeader zfh; + size_t const err = ZSTD_getFrameHeader(&zfh, src, srcSize); + if (ZSTD_isError(err)) return err; + RETURN_ERROR_IF(err>0, srcSize_wrong, ""); + RETURN_ERROR_IF(zfh.windowSize > windowSizeMax, + frameParameter_windowTooLarge, ""); + return ZSTD_estimateDStreamSize((size_t)zfh.windowSize); +} + + +/* ***** Decompression ***** */ + +static int ZSTD_DCtx_isOverflow(ZSTD_DStream* zds, size_t const neededInBuffSize, size_t const neededOutBuffSize) +{ + return (zds->inBuffSize + zds->outBuffSize) >= (neededInBuffSize + neededOutBuffSize) * ZSTD_WORKSPACETOOLARGE_FACTOR; +} + +static void ZSTD_DCtx_updateOversizedDuration(ZSTD_DStream* zds, size_t const neededInBuffSize, size_t const neededOutBuffSize) +{ + if (ZSTD_DCtx_isOverflow(zds, neededInBuffSize, neededOutBuffSize)) + zds->oversizedDuration++; + else + zds->oversizedDuration = 0; +} + +static int ZSTD_DCtx_isOversizedTooLong(ZSTD_DStream* zds) +{ + return zds->oversizedDuration >= ZSTD_WORKSPACETOOLARGE_MAXDURATION; +} + +/* Checks that the output buffer hasn't changed if ZSTD_obm_stable is used. */ +static size_t ZSTD_checkOutBuffer(ZSTD_DStream const* zds, ZSTD_outBuffer const* output) +{ + ZSTD_outBuffer const expect = zds->expectedOutBuffer; + /* No requirement when ZSTD_obm_stable is not enabled. */ + if (zds->outBufferMode != ZSTD_bm_stable) + return 0; + /* Any buffer is allowed in zdss_init, this must be the same for every other call until + * the context is reset. + */ + if (zds->streamStage == zdss_init) + return 0; + /* The buffer must match our expectation exactly. */ + if (expect.dst == output->dst && expect.pos == output->pos && expect.size == output->size) + return 0; + RETURN_ERROR(dstBuffer_wrong, "ZSTD_d_stableOutBuffer enabled but output differs!"); +} + +/* Calls ZSTD_decompressContinue() with the right parameters for ZSTD_decompressStream() + * and updates the stage and the output buffer state. This call is extracted so it can be + * used both when reading directly from the ZSTD_inBuffer, and in buffered input mode. + * NOTE: You must break after calling this function since the streamStage is modified. + */ +static size_t ZSTD_decompressContinueStream( + ZSTD_DStream* zds, char** op, char* oend, + void const* src, size_t srcSize) { + int const isSkipFrame = ZSTD_isSkipFrame(zds); + if (zds->outBufferMode == ZSTD_bm_buffered) { + size_t const dstSize = isSkipFrame ? 0 : zds->outBuffSize - zds->outStart; + size_t const decodedSize = ZSTD_decompressContinue(zds, + zds->outBuff + zds->outStart, dstSize, src, srcSize); + FORWARD_IF_ERROR(decodedSize, ""); + if (!decodedSize && !isSkipFrame) { + zds->streamStage = zdss_read; + } else { + zds->outEnd = zds->outStart + decodedSize; + zds->streamStage = zdss_flush; + } + } else { + /* Write directly into the output buffer */ + size_t const dstSize = isSkipFrame ? 0 : (size_t)(oend - *op); + size_t const decodedSize = ZSTD_decompressContinue(zds, *op, dstSize, src, srcSize); + FORWARD_IF_ERROR(decodedSize, ""); + *op += decodedSize; + /* Flushing is not needed. */ + zds->streamStage = zdss_read; + assert(*op <= oend); + assert(zds->outBufferMode == ZSTD_bm_stable); + } + return 0; +} + +size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input) +{ + const char* const src = (const char*)input->src; + const char* const istart = input->pos != 0 ? src + input->pos : src; + const char* const iend = input->size != 0 ? src + input->size : src; + const char* ip = istart; + char* const dst = (char*)output->dst; + char* const ostart = output->pos != 0 ? dst + output->pos : dst; + char* const oend = output->size != 0 ? dst + output->size : dst; + char* op = ostart; + U32 someMoreWork = 1; + + DEBUGLOG(5, "ZSTD_decompressStream"); + RETURN_ERROR_IF( + input->pos > input->size, + srcSize_wrong, + "forbidden. in: pos: %u vs size: %u", + (U32)input->pos, (U32)input->size); + RETURN_ERROR_IF( + output->pos > output->size, + dstSize_tooSmall, + "forbidden. out: pos: %u vs size: %u", + (U32)output->pos, (U32)output->size); + DEBUGLOG(5, "input size : %u", (U32)(input->size - input->pos)); + FORWARD_IF_ERROR(ZSTD_checkOutBuffer(zds, output), ""); + + while (someMoreWork) { + switch(zds->streamStage) + { + case zdss_init : + DEBUGLOG(5, "stage zdss_init => transparent reset "); + zds->streamStage = zdss_loadHeader; + zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0; +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) + zds->legacyVersion = 0; +#endif + zds->hostageByte = 0; + zds->expectedOutBuffer = *output; + ZSTD_FALLTHROUGH; + + case zdss_loadHeader : + DEBUGLOG(5, "stage zdss_loadHeader (srcSize : %u)", (U32)(iend - ip)); +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) + if (zds->legacyVersion) { + RETURN_ERROR_IF(zds->staticSize, memory_allocation, + "legacy support is incompatible with static dctx"); + { size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input); + if (hint==0) zds->streamStage = zdss_init; + return hint; + } } +#endif + { size_t const hSize = ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format); + if (zds->refMultipleDDicts && zds->ddictSet) { + ZSTD_DCtx_selectFrameDDict(zds); + } + if (ZSTD_isError(hSize)) { +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) + U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart); + if (legacyVersion) { + ZSTD_DDict const* const ddict = ZSTD_getDDict(zds); + const void* const dict = ddict ? ZSTD_DDict_dictContent(ddict) : NULL; + size_t const dictSize = ddict ? ZSTD_DDict_dictSize(ddict) : 0; + DEBUGLOG(5, "ZSTD_decompressStream: detected legacy version v0.%u", legacyVersion); + RETURN_ERROR_IF(zds->staticSize, memory_allocation, + "legacy support is incompatible with static dctx"); + FORWARD_IF_ERROR(ZSTD_initLegacyStream(&zds->legacyContext, + zds->previousLegacyVersion, legacyVersion, + dict, dictSize), ""); + zds->legacyVersion = zds->previousLegacyVersion = legacyVersion; + { size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, legacyVersion, output, input); + if (hint==0) zds->streamStage = zdss_init; /* or stay in stage zdss_loadHeader */ + return hint; + } } +#endif + return hSize; /* error */ + } + if (hSize != 0) { /* need more input */ + size_t const toLoad = hSize - zds->lhSize; /* if hSize!=0, hSize > zds->lhSize */ + size_t const remainingInput = (size_t)(iend-ip); + assert(iend >= ip); + if (toLoad > remainingInput) { /* not enough input to load full header */ + if (remainingInput > 0) { + ZSTD_memcpy(zds->headerBuffer + zds->lhSize, ip, remainingInput); + zds->lhSize += remainingInput; + } + input->pos = input->size; + /* check first few bytes */ + FORWARD_IF_ERROR( + ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format), + "First few bytes detected incorrect" ); + /* return hint input size */ + return (MAX((size_t)ZSTD_FRAMEHEADERSIZE_MIN(zds->format), hSize) - zds->lhSize) + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */ + } + assert(ip != NULL); + ZSTD_memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad; + break; + } } + + /* check for single-pass mode opportunity */ + if (zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN + && zds->fParams.frameType != ZSTD_skippableFrame + && (U64)(size_t)(oend-op) >= zds->fParams.frameContentSize) { + size_t const cSize = ZSTD_findFrameCompressedSize_advanced(istart, (size_t)(iend-istart), zds->format); + if (cSize <= (size_t)(iend-istart)) { + /* shortcut : using single-pass mode */ + size_t const decompressedSize = ZSTD_decompress_usingDDict(zds, op, (size_t)(oend-op), istart, cSize, ZSTD_getDDict(zds)); + if (ZSTD_isError(decompressedSize)) return decompressedSize; + DEBUGLOG(4, "shortcut to single-pass ZSTD_decompress_usingDDict()"); + assert(istart != NULL); + ip = istart + cSize; + op = op ? op + decompressedSize : op; /* can occur if frameContentSize = 0 (empty frame) */ + zds->expected = 0; + zds->streamStage = zdss_init; + someMoreWork = 0; + break; + } } + + /* Check output buffer is large enough for ZSTD_odm_stable. */ + if (zds->outBufferMode == ZSTD_bm_stable + && zds->fParams.frameType != ZSTD_skippableFrame + && zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN + && (U64)(size_t)(oend-op) < zds->fParams.frameContentSize) { + RETURN_ERROR(dstSize_tooSmall, "ZSTD_obm_stable passed but ZSTD_outBuffer is too small"); + } + + /* Consume header (see ZSTDds_decodeFrameHeader) */ + DEBUGLOG(4, "Consume header"); + FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(zds, ZSTD_getDDict(zds)), ""); + + if (zds->format == ZSTD_f_zstd1 + && (MEM_readLE32(zds->headerBuffer) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */ + zds->expected = MEM_readLE32(zds->headerBuffer + ZSTD_FRAMEIDSIZE); + zds->stage = ZSTDds_skipFrame; + } else { + FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(zds, zds->headerBuffer, zds->lhSize), ""); + zds->expected = ZSTD_blockHeaderSize; + zds->stage = ZSTDds_decodeBlockHeader; + } + + /* control buffer memory usage */ + DEBUGLOG(4, "Control max memory usage (%u KB <= max %u KB)", + (U32)(zds->fParams.windowSize >>10), + (U32)(zds->maxWindowSize >> 10) ); + zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN); + RETURN_ERROR_IF(zds->fParams.windowSize > zds->maxWindowSize, + frameParameter_windowTooLarge, ""); + if (zds->maxBlockSizeParam != 0) + zds->fParams.blockSizeMax = MIN(zds->fParams.blockSizeMax, (unsigned)zds->maxBlockSizeParam); + + /* Adapt buffer sizes to frame header instructions */ + { size_t const neededInBuffSize = MAX(zds->fParams.blockSizeMax, 4 /* frame checksum */); + size_t const neededOutBuffSize = zds->outBufferMode == ZSTD_bm_buffered + ? ZSTD_decodingBufferSize_internal(zds->fParams.windowSize, zds->fParams.frameContentSize, zds->fParams.blockSizeMax) + : 0; + + ZSTD_DCtx_updateOversizedDuration(zds, neededInBuffSize, neededOutBuffSize); + + { int const tooSmall = (zds->inBuffSize < neededInBuffSize) || (zds->outBuffSize < neededOutBuffSize); + int const tooLarge = ZSTD_DCtx_isOversizedTooLong(zds); + + if (tooSmall || tooLarge) { + size_t const bufferSize = neededInBuffSize + neededOutBuffSize; + DEBUGLOG(4, "inBuff : from %u to %u", + (U32)zds->inBuffSize, (U32)neededInBuffSize); + DEBUGLOG(4, "outBuff : from %u to %u", + (U32)zds->outBuffSize, (U32)neededOutBuffSize); + if (zds->staticSize) { /* static DCtx */ + DEBUGLOG(4, "staticSize : %u", (U32)zds->staticSize); + assert(zds->staticSize >= sizeof(ZSTD_DCtx)); /* controlled at init */ + RETURN_ERROR_IF( + bufferSize > zds->staticSize - sizeof(ZSTD_DCtx), + memory_allocation, ""); + } else { + ZSTD_customFree(zds->inBuff, zds->customMem); + zds->inBuffSize = 0; + zds->outBuffSize = 0; + zds->inBuff = (char*)ZSTD_customMalloc(bufferSize, zds->customMem); + RETURN_ERROR_IF(zds->inBuff == NULL, memory_allocation, ""); + } + zds->inBuffSize = neededInBuffSize; + zds->outBuff = zds->inBuff + zds->inBuffSize; + zds->outBuffSize = neededOutBuffSize; + } } } + zds->streamStage = zdss_read; + ZSTD_FALLTHROUGH; + + case zdss_read: + DEBUGLOG(5, "stage zdss_read"); + { size_t const neededInSize = ZSTD_nextSrcSizeToDecompressWithInputSize(zds, (size_t)(iend - ip)); + DEBUGLOG(5, "neededInSize = %u", (U32)neededInSize); + if (neededInSize==0) { /* end of frame */ + zds->streamStage = zdss_init; + someMoreWork = 0; + break; + } + if ((size_t)(iend-ip) >= neededInSize) { /* decode directly from src */ + FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, ip, neededInSize), ""); + assert(ip != NULL); + ip += neededInSize; + /* Function modifies the stage so we must break */ + break; + } } + if (ip==iend) { someMoreWork = 0; break; } /* no more input */ + zds->streamStage = zdss_load; + ZSTD_FALLTHROUGH; + + case zdss_load: + { size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds); + size_t const toLoad = neededInSize - zds->inPos; + int const isSkipFrame = ZSTD_isSkipFrame(zds); + size_t loadedSize; + /* At this point we shouldn't be decompressing a block that we can stream. */ + assert(neededInSize == ZSTD_nextSrcSizeToDecompressWithInputSize(zds, (size_t)(iend - ip))); + if (isSkipFrame) { + loadedSize = MIN(toLoad, (size_t)(iend-ip)); + } else { + RETURN_ERROR_IF(toLoad > zds->inBuffSize - zds->inPos, + corruption_detected, + "should never happen"); + loadedSize = ZSTD_limitCopy(zds->inBuff + zds->inPos, toLoad, ip, (size_t)(iend-ip)); + } + if (loadedSize != 0) { + /* ip may be NULL */ + ip += loadedSize; + zds->inPos += loadedSize; + } + if (loadedSize < toLoad) { someMoreWork = 0; break; } /* not enough input, wait for more */ + + /* decode loaded input */ + zds->inPos = 0; /* input is consumed */ + FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, zds->inBuff, neededInSize), ""); + /* Function modifies the stage so we must break */ + break; + } + case zdss_flush: + { + size_t const toFlushSize = zds->outEnd - zds->outStart; + size_t const flushedSize = ZSTD_limitCopy(op, (size_t)(oend-op), zds->outBuff + zds->outStart, toFlushSize); + + op = op ? op + flushedSize : op; + + zds->outStart += flushedSize; + if (flushedSize == toFlushSize) { /* flush completed */ + zds->streamStage = zdss_read; + if ( (zds->outBuffSize < zds->fParams.frameContentSize) + && (zds->outStart + zds->fParams.blockSizeMax > zds->outBuffSize) ) { + DEBUGLOG(5, "restart filling outBuff from beginning (left:%i, needed:%u)", + (int)(zds->outBuffSize - zds->outStart), + (U32)zds->fParams.blockSizeMax); + zds->outStart = zds->outEnd = 0; + } + break; + } } + /* cannot complete flush */ + someMoreWork = 0; + break; + + default: + assert(0); /* impossible */ + RETURN_ERROR(GENERIC, "impossible to reach"); /* some compilers require default to do something */ + } } + + /* result */ + input->pos = (size_t)(ip - (const char*)(input->src)); + output->pos = (size_t)(op - (char*)(output->dst)); + + /* Update the expected output buffer for ZSTD_obm_stable. */ + zds->expectedOutBuffer = *output; + + if ((ip==istart) && (op==ostart)) { /* no forward progress */ + zds->noForwardProgress ++; + if (zds->noForwardProgress >= ZSTD_NO_FORWARD_PROGRESS_MAX) { + RETURN_ERROR_IF(op==oend, noForwardProgress_destFull, ""); + RETURN_ERROR_IF(ip==iend, noForwardProgress_inputEmpty, ""); + assert(0); + } + } else { + zds->noForwardProgress = 0; + } + { size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds); + if (!nextSrcSizeHint) { /* frame fully decoded */ + if (zds->outEnd == zds->outStart) { /* output fully flushed */ + if (zds->hostageByte) { + if (input->pos >= input->size) { + /* can't release hostage (not present) */ + zds->streamStage = zdss_read; + return 1; + } + input->pos++; /* release hostage */ + } /* zds->hostageByte */ + return 0; + } /* zds->outEnd == zds->outStart */ + if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */ + input->pos--; /* note : pos > 0, otherwise, impossible to finish reading last block */ + zds->hostageByte=1; + } + return 1; + } /* nextSrcSizeHint==0 */ + nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds) == ZSTDnit_block); /* preload header of next block */ + assert(zds->inPos <= nextSrcSizeHint); + nextSrcSizeHint -= zds->inPos; /* part already loaded*/ + return nextSrcSizeHint; + } +} + +size_t ZSTD_decompressStream_simpleArgs ( + ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, size_t* dstPos, + const void* src, size_t srcSize, size_t* srcPos) +{ + ZSTD_outBuffer output; + ZSTD_inBuffer input; + output.dst = dst; + output.size = dstCapacity; + output.pos = *dstPos; + input.src = src; + input.size = srcSize; + input.pos = *srcPos; + { size_t const cErr = ZSTD_decompressStream(dctx, &output, &input); + *dstPos = output.pos; + *srcPos = input.pos; + return cErr; + } +} diff --git a/third_party/zstd/lib/decompress/zstd_decompress_block.c b/third_party/zstd/lib/decompress/zstd_decompress_block.c new file mode 100644 index 0000000000..76d7332e88 --- /dev/null +++ b/third_party/zstd/lib/decompress/zstd_decompress_block.c @@ -0,0 +1,2215 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + +/* zstd_decompress_block : + * this module takes care of decompressing _compressed_ block */ + +/*-******************************************************* +* Dependencies +*********************************************************/ +#include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memmove, ZSTD_memset */ +#include "../common/compiler.h" /* prefetch */ +#include "../common/cpu.h" /* bmi2 */ +#include "../common/mem.h" /* low level memory routines */ +#define FSE_STATIC_LINKING_ONLY +#include "../common/fse.h" +#include "../common/huf.h" +#include "../common/zstd_internal.h" +#include "zstd_decompress_internal.h" /* ZSTD_DCtx */ +#include "zstd_ddict.h" /* ZSTD_DDictDictContent */ +#include "zstd_decompress_block.h" +#include "../common/bits.h" /* ZSTD_highbit32 */ + +/*_******************************************************* +* Macros +**********************************************************/ + +/* These two optional macros force the use one way or another of the two + * ZSTD_decompressSequences implementations. You can't force in both directions + * at the same time. + */ +#if defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ + defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) +#error "Cannot force the use of the short and the long ZSTD_decompressSequences variants!" +#endif + + +/*_******************************************************* +* Memory operations +**********************************************************/ +static void ZSTD_copy4(void* dst, const void* src) { ZSTD_memcpy(dst, src, 4); } + + +/*-************************************************************* + * Block decoding + ***************************************************************/ + +static size_t ZSTD_blockSizeMax(ZSTD_DCtx const* dctx) +{ + size_t const blockSizeMax = dctx->isFrameDecompression ? dctx->fParams.blockSizeMax : ZSTD_BLOCKSIZE_MAX; + assert(blockSizeMax <= ZSTD_BLOCKSIZE_MAX); + return blockSizeMax; +} + +/*! ZSTD_getcBlockSize() : + * Provides the size of compressed block from block header `src` */ +size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, + blockProperties_t* bpPtr) +{ + RETURN_ERROR_IF(srcSize < ZSTD_blockHeaderSize, srcSize_wrong, ""); + + { U32 const cBlockHeader = MEM_readLE24(src); + U32 const cSize = cBlockHeader >> 3; + bpPtr->lastBlock = cBlockHeader & 1; + bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3); + bpPtr->origSize = cSize; /* only useful for RLE */ + if (bpPtr->blockType == bt_rle) return 1; + RETURN_ERROR_IF(bpPtr->blockType == bt_reserved, corruption_detected, ""); + return cSize; + } +} + +/* Allocate buffer for literals, either overlapping current dst, or split between dst and litExtraBuffer, or stored entirely within litExtraBuffer */ +static void ZSTD_allocateLiteralsBuffer(ZSTD_DCtx* dctx, void* const dst, const size_t dstCapacity, const size_t litSize, + const streaming_operation streaming, const size_t expectedWriteSize, const unsigned splitImmediately) +{ + size_t const blockSizeMax = ZSTD_blockSizeMax(dctx); + assert(litSize <= blockSizeMax); + assert(dctx->isFrameDecompression || streaming == not_streaming); + assert(expectedWriteSize <= blockSizeMax); + if (streaming == not_streaming && dstCapacity > blockSizeMax + WILDCOPY_OVERLENGTH + litSize + WILDCOPY_OVERLENGTH) { + /* If we aren't streaming, we can just put the literals after the output + * of the current block. We don't need to worry about overwriting the + * extDict of our window, because it doesn't exist. + * So if we have space after the end of the block, just put it there. + */ + dctx->litBuffer = (BYTE*)dst + blockSizeMax + WILDCOPY_OVERLENGTH; + dctx->litBufferEnd = dctx->litBuffer + litSize; + dctx->litBufferLocation = ZSTD_in_dst; + } else if (litSize <= ZSTD_LITBUFFEREXTRASIZE) { + /* Literals fit entirely within the extra buffer, put them there to avoid + * having to split the literals. + */ + dctx->litBuffer = dctx->litExtraBuffer; + dctx->litBufferEnd = dctx->litBuffer + litSize; + dctx->litBufferLocation = ZSTD_not_in_dst; + } else { + assert(blockSizeMax > ZSTD_LITBUFFEREXTRASIZE); + /* Literals must be split between the output block and the extra lit + * buffer. We fill the extra lit buffer with the tail of the literals, + * and put the rest of the literals at the end of the block, with + * WILDCOPY_OVERLENGTH of buffer room to allow for overreads. + * This MUST not write more than our maxBlockSize beyond dst, because in + * streaming mode, that could overwrite part of our extDict window. + */ + if (splitImmediately) { + /* won't fit in litExtraBuffer, so it will be split between end of dst and extra buffer */ + dctx->litBuffer = (BYTE*)dst + expectedWriteSize - litSize + ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH; + dctx->litBufferEnd = dctx->litBuffer + litSize - ZSTD_LITBUFFEREXTRASIZE; + } else { + /* initially this will be stored entirely in dst during huffman decoding, it will partially be shifted to litExtraBuffer after */ + dctx->litBuffer = (BYTE*)dst + expectedWriteSize - litSize; + dctx->litBufferEnd = (BYTE*)dst + expectedWriteSize; + } + dctx->litBufferLocation = ZSTD_split; + assert(dctx->litBufferEnd <= (BYTE*)dst + expectedWriteSize); + } +} + +/*! ZSTD_decodeLiteralsBlock() : + * Where it is possible to do so without being stomped by the output during decompression, the literals block will be stored + * 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 + * block will be output. Otherwise it will be stored at the end of the current dst blockspace, with a small portion being + * stored in dctx->litExtraBuffer to help keep it "ahead" of the current output write. + * + * @return : nb of bytes read from src (< srcSize ) + * note : symbol not declared but exposed for fullbench */ +static size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx, + const void* src, size_t srcSize, /* note : srcSize < BLOCKSIZE */ + void* dst, size_t dstCapacity, const streaming_operation streaming) +{ + DEBUGLOG(5, "ZSTD_decodeLiteralsBlock"); + RETURN_ERROR_IF(srcSize < MIN_CBLOCK_SIZE, corruption_detected, ""); + + { const BYTE* const istart = (const BYTE*) src; + symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3); + size_t const blockSizeMax = ZSTD_blockSizeMax(dctx); + + switch(litEncType) + { + case set_repeat: + DEBUGLOG(5, "set_repeat flag : re-using stats from previous compressed literals block"); + RETURN_ERROR_IF(dctx->litEntropy==0, dictionary_corrupted, ""); + ZSTD_FALLTHROUGH; + + case set_compressed: + RETURN_ERROR_IF(srcSize < 5, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need up to 5 for case 3"); + { size_t lhSize, litSize, litCSize; + U32 singleStream=0; + U32 const lhlCode = (istart[0] >> 2) & 3; + U32 const lhc = MEM_readLE32(istart); + size_t hufSuccess; + size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity); + int const flags = 0 + | (ZSTD_DCtx_get_bmi2(dctx) ? HUF_flags_bmi2 : 0) + | (dctx->disableHufAsm ? HUF_flags_disableAsm : 0); + switch(lhlCode) + { + case 0: case 1: default: /* note : default is impossible, since lhlCode into [0..3] */ + /* 2 - 2 - 10 - 10 */ + singleStream = !lhlCode; + lhSize = 3; + litSize = (lhc >> 4) & 0x3FF; + litCSize = (lhc >> 14) & 0x3FF; + break; + case 2: + /* 2 - 2 - 14 - 14 */ + lhSize = 4; + litSize = (lhc >> 4) & 0x3FFF; + litCSize = lhc >> 18; + break; + case 3: + /* 2 - 2 - 18 - 18 */ + lhSize = 5; + litSize = (lhc >> 4) & 0x3FFFF; + litCSize = (lhc >> 22) + ((size_t)istart[4] << 10); + break; + } + RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled"); + RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, ""); + if (!singleStream) + RETURN_ERROR_IF(litSize < MIN_LITERALS_FOR_4_STREAMS, literals_headerWrong, + "Not enough literals (%zu) for the 4-streams mode (min %u)", + litSize, MIN_LITERALS_FOR_4_STREAMS); + RETURN_ERROR_IF(litCSize + lhSize > srcSize, corruption_detected, ""); + RETURN_ERROR_IF(expectedWriteSize < litSize , dstSize_tooSmall, ""); + ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 0); + + /* prefetch huffman table if cold */ + if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) { + PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable)); + } + + if (litEncType==set_repeat) { + if (singleStream) { + hufSuccess = HUF_decompress1X_usingDTable( + dctx->litBuffer, litSize, istart+lhSize, litCSize, + dctx->HUFptr, flags); + } else { + assert(litSize >= MIN_LITERALS_FOR_4_STREAMS); + hufSuccess = HUF_decompress4X_usingDTable( + dctx->litBuffer, litSize, istart+lhSize, litCSize, + dctx->HUFptr, flags); + } + } else { + if (singleStream) { +#if defined(HUF_FORCE_DECOMPRESS_X2) + hufSuccess = HUF_decompress1X_DCtx_wksp( + dctx->entropy.hufTable, dctx->litBuffer, litSize, + istart+lhSize, litCSize, dctx->workspace, + sizeof(dctx->workspace), flags); +#else + hufSuccess = HUF_decompress1X1_DCtx_wksp( + dctx->entropy.hufTable, dctx->litBuffer, litSize, + istart+lhSize, litCSize, dctx->workspace, + sizeof(dctx->workspace), flags); +#endif + } else { + hufSuccess = HUF_decompress4X_hufOnly_wksp( + dctx->entropy.hufTable, dctx->litBuffer, litSize, + istart+lhSize, litCSize, dctx->workspace, + sizeof(dctx->workspace), flags); + } + } + if (dctx->litBufferLocation == ZSTD_split) + { + assert(litSize > ZSTD_LITBUFFEREXTRASIZE); + ZSTD_memcpy(dctx->litExtraBuffer, dctx->litBufferEnd - ZSTD_LITBUFFEREXTRASIZE, ZSTD_LITBUFFEREXTRASIZE); + ZSTD_memmove(dctx->litBuffer + ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH, dctx->litBuffer, litSize - ZSTD_LITBUFFEREXTRASIZE); + dctx->litBuffer += ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH; + dctx->litBufferEnd -= WILDCOPY_OVERLENGTH; + assert(dctx->litBufferEnd <= (BYTE*)dst + blockSizeMax); + } + + RETURN_ERROR_IF(HUF_isError(hufSuccess), corruption_detected, ""); + + dctx->litPtr = dctx->litBuffer; + dctx->litSize = litSize; + dctx->litEntropy = 1; + if (litEncType==set_compressed) dctx->HUFptr = dctx->entropy.hufTable; + return litCSize + lhSize; + } + + case set_basic: + { size_t litSize, lhSize; + U32 const lhlCode = ((istart[0]) >> 2) & 3; + size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity); + switch(lhlCode) + { + case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */ + lhSize = 1; + litSize = istart[0] >> 3; + break; + case 1: + lhSize = 2; + litSize = MEM_readLE16(istart) >> 4; + break; + case 3: + lhSize = 3; + RETURN_ERROR_IF(srcSize<3, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize = 3"); + litSize = MEM_readLE24(istart) >> 4; + break; + } + + RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled"); + RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, ""); + RETURN_ERROR_IF(expectedWriteSize < litSize, dstSize_tooSmall, ""); + ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 1); + if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */ + RETURN_ERROR_IF(litSize+lhSize > srcSize, corruption_detected, ""); + if (dctx->litBufferLocation == ZSTD_split) + { + ZSTD_memcpy(dctx->litBuffer, istart + lhSize, litSize - ZSTD_LITBUFFEREXTRASIZE); + ZSTD_memcpy(dctx->litExtraBuffer, istart + lhSize + litSize - ZSTD_LITBUFFEREXTRASIZE, ZSTD_LITBUFFEREXTRASIZE); + } + else + { + ZSTD_memcpy(dctx->litBuffer, istart + lhSize, litSize); + } + dctx->litPtr = dctx->litBuffer; + dctx->litSize = litSize; + return lhSize+litSize; + } + /* direct reference into compressed stream */ + dctx->litPtr = istart+lhSize; + dctx->litSize = litSize; + dctx->litBufferEnd = dctx->litPtr + litSize; + dctx->litBufferLocation = ZSTD_not_in_dst; + return lhSize+litSize; + } + + case set_rle: + { U32 const lhlCode = ((istart[0]) >> 2) & 3; + size_t litSize, lhSize; + size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity); + switch(lhlCode) + { + case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */ + lhSize = 1; + litSize = istart[0] >> 3; + break; + case 1: + lhSize = 2; + RETURN_ERROR_IF(srcSize<3, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize+1 = 3"); + litSize = MEM_readLE16(istart) >> 4; + break; + case 3: + lhSize = 3; + RETURN_ERROR_IF(srcSize<4, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize+1 = 4"); + litSize = MEM_readLE24(istart) >> 4; + break; + } + RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled"); + RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, ""); + RETURN_ERROR_IF(expectedWriteSize < litSize, dstSize_tooSmall, ""); + ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 1); + if (dctx->litBufferLocation == ZSTD_split) + { + ZSTD_memset(dctx->litBuffer, istart[lhSize], litSize - ZSTD_LITBUFFEREXTRASIZE); + ZSTD_memset(dctx->litExtraBuffer, istart[lhSize], ZSTD_LITBUFFEREXTRASIZE); + } + else + { + ZSTD_memset(dctx->litBuffer, istart[lhSize], litSize); + } + dctx->litPtr = dctx->litBuffer; + dctx->litSize = litSize; + return lhSize+1; + } + default: + RETURN_ERROR(corruption_detected, "impossible"); + } + } +} + +/* Hidden declaration for fullbench */ +size_t ZSTD_decodeLiteralsBlock_wrapper(ZSTD_DCtx* dctx, + const void* src, size_t srcSize, + void* dst, size_t dstCapacity); +size_t ZSTD_decodeLiteralsBlock_wrapper(ZSTD_DCtx* dctx, + const void* src, size_t srcSize, + void* dst, size_t dstCapacity) +{ + dctx->isFrameDecompression = 0; + return ZSTD_decodeLiteralsBlock(dctx, src, srcSize, dst, dstCapacity, not_streaming); +} + +/* Default FSE distribution tables. + * These are pre-calculated FSE decoding tables using default distributions as defined in specification : + * https://github.com/facebook/zstd/blob/release/doc/zstd_compression_format.md#default-distributions + * They were generated programmatically with following method : + * - start from default distributions, present in /lib/common/zstd_internal.h + * - generate tables normally, using ZSTD_buildFSETable() + * - printout the content of tables + * - pretify output, report below, test with fuzzer to ensure it's correct */ + +/* Default FSE distribution table for Literal Lengths */ +static const ZSTD_seqSymbol LL_defaultDTable[(1<tableLog = 0; + DTableH->fastMode = 0; + + cell->nbBits = 0; + cell->nextState = 0; + assert(nbAddBits < 255); + cell->nbAdditionalBits = nbAddBits; + cell->baseValue = baseValue; +} + + +/* ZSTD_buildFSETable() : + * generate FSE decoding table for one symbol (ll, ml or off) + * cannot fail if input is valid => + * all inputs are presumed validated at this stage */ +FORCE_INLINE_TEMPLATE +void ZSTD_buildFSETable_body(ZSTD_seqSymbol* dt, + const short* normalizedCounter, unsigned maxSymbolValue, + const U32* baseValue, const U8* nbAdditionalBits, + unsigned tableLog, void* wksp, size_t wkspSize) +{ + ZSTD_seqSymbol* const tableDecode = dt+1; + U32 const maxSV1 = maxSymbolValue + 1; + U32 const tableSize = 1 << tableLog; + + U16* symbolNext = (U16*)wksp; + BYTE* spread = (BYTE*)(symbolNext + MaxSeq + 1); + U32 highThreshold = tableSize - 1; + + + /* Sanity Checks */ + assert(maxSymbolValue <= MaxSeq); + assert(tableLog <= MaxFSELog); + assert(wkspSize >= ZSTD_BUILD_FSE_TABLE_WKSP_SIZE); + (void)wkspSize; + /* Init, lay down lowprob symbols */ + { ZSTD_seqSymbol_header DTableH; + DTableH.tableLog = tableLog; + DTableH.fastMode = 1; + { S16 const largeLimit= (S16)(1 << (tableLog-1)); + U32 s; + for (s=0; s= largeLimit) DTableH.fastMode=0; + assert(normalizedCounter[s]>=0); + symbolNext[s] = (U16)normalizedCounter[s]; + } } } + ZSTD_memcpy(dt, &DTableH, sizeof(DTableH)); + } + + /* Spread symbols */ + assert(tableSize <= 512); + /* Specialized symbol spreading for the case when there are + * no low probability (-1 count) symbols. When compressing + * small blocks we avoid low probability symbols to hit this + * case, since header decoding speed matters more. + */ + if (highThreshold == tableSize - 1) { + size_t const tableMask = tableSize-1; + size_t const step = FSE_TABLESTEP(tableSize); + /* First lay down the symbols in order. + * We use a uint64_t to lay down 8 bytes at a time. This reduces branch + * misses since small blocks generally have small table logs, so nearly + * all symbols have counts <= 8. We ensure we have 8 bytes at the end of + * our buffer to handle the over-write. + */ + { + U64 const add = 0x0101010101010101ull; + size_t pos = 0; + U64 sv = 0; + U32 s; + for (s=0; s=0); + pos += (size_t)n; + } + } + /* Now we spread those positions across the table. + * The benefit of doing it in two stages is that we avoid the + * variable size inner loop, which caused lots of branch misses. + * Now we can run through all the positions without any branch misses. + * We unroll the loop twice, since that is what empirically worked best. + */ + { + size_t position = 0; + size_t s; + size_t const unroll = 2; + assert(tableSize % unroll == 0); /* FSE_MIN_TABLELOG is 5 */ + for (s = 0; s < (size_t)tableSize; s += unroll) { + size_t u; + for (u = 0; u < unroll; ++u) { + size_t const uPosition = (position + (u * step)) & tableMask; + tableDecode[uPosition].baseValue = spread[s + u]; + } + position = (position + (unroll * step)) & tableMask; + } + assert(position == 0); + } + } else { + U32 const tableMask = tableSize-1; + U32 const step = FSE_TABLESTEP(tableSize); + U32 s, position = 0; + for (s=0; s highThreshold)) position = (position + step) & tableMask; /* lowprob area */ + } } + assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */ + } + + /* Build Decoding table */ + { + U32 u; + for (u=0; u max, corruption_detected, ""); + { U32 const symbol = *(const BYTE*)src; + U32 const baseline = baseValue[symbol]; + U8 const nbBits = nbAdditionalBits[symbol]; + ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits); + } + *DTablePtr = DTableSpace; + return 1; + case set_basic : + *DTablePtr = defaultTable; + return 0; + case set_repeat: + RETURN_ERROR_IF(!flagRepeatTable, corruption_detected, ""); + /* prefetch FSE table if used */ + if (ddictIsCold && (nbSeq > 24 /* heuristic */)) { + const void* const pStart = *DTablePtr; + size_t const pSize = sizeof(ZSTD_seqSymbol) * (SEQSYMBOL_TABLE_SIZE(maxLog)); + PREFETCH_AREA(pStart, pSize); + } + return 0; + case set_compressed : + { unsigned tableLog; + S16 norm[MaxSeq+1]; + size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize); + RETURN_ERROR_IF(FSE_isError(headerSize), corruption_detected, ""); + RETURN_ERROR_IF(tableLog > maxLog, corruption_detected, ""); + ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog, wksp, wkspSize, bmi2); + *DTablePtr = DTableSpace; + return headerSize; + } + default : + assert(0); + RETURN_ERROR(GENERIC, "impossible"); + } +} + +size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr, + const void* src, size_t srcSize) +{ + const BYTE* const istart = (const BYTE*)src; + const BYTE* const iend = istart + srcSize; + const BYTE* ip = istart; + int nbSeq; + DEBUGLOG(5, "ZSTD_decodeSeqHeaders"); + + /* check */ + RETURN_ERROR_IF(srcSize < MIN_SEQUENCES_SIZE, srcSize_wrong, ""); + + /* SeqHead */ + nbSeq = *ip++; + if (nbSeq > 0x7F) { + if (nbSeq == 0xFF) { + RETURN_ERROR_IF(ip+2 > iend, srcSize_wrong, ""); + nbSeq = MEM_readLE16(ip) + LONGNBSEQ; + ip+=2; + } else { + RETURN_ERROR_IF(ip >= iend, srcSize_wrong, ""); + nbSeq = ((nbSeq-0x80)<<8) + *ip++; + } + } + *nbSeqPtr = nbSeq; + + if (nbSeq == 0) { + /* No sequence : section ends immediately */ + RETURN_ERROR_IF(ip != iend, corruption_detected, + "extraneous data present in the Sequences section"); + return (size_t)(ip - istart); + } + + /* FSE table descriptors */ + RETURN_ERROR_IF(ip+1 > iend, srcSize_wrong, ""); /* minimum possible size: 1 byte for symbol encoding types */ + RETURN_ERROR_IF(*ip & 3, corruption_detected, ""); /* The last field, Reserved, must be all-zeroes. */ + { symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6); + symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3); + symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3); + ip++; + + /* Build DTables */ + { size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr, + LLtype, MaxLL, LLFSELog, + ip, iend-ip, + LL_base, LL_bits, + LL_defaultDTable, dctx->fseEntropy, + dctx->ddictIsCold, nbSeq, + dctx->workspace, sizeof(dctx->workspace), + ZSTD_DCtx_get_bmi2(dctx)); + RETURN_ERROR_IF(ZSTD_isError(llhSize), corruption_detected, "ZSTD_buildSeqTable failed"); + ip += llhSize; + } + + { size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr, + OFtype, MaxOff, OffFSELog, + ip, iend-ip, + OF_base, OF_bits, + OF_defaultDTable, dctx->fseEntropy, + dctx->ddictIsCold, nbSeq, + dctx->workspace, sizeof(dctx->workspace), + ZSTD_DCtx_get_bmi2(dctx)); + RETURN_ERROR_IF(ZSTD_isError(ofhSize), corruption_detected, "ZSTD_buildSeqTable failed"); + ip += ofhSize; + } + + { size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr, + MLtype, MaxML, MLFSELog, + ip, iend-ip, + ML_base, ML_bits, + ML_defaultDTable, dctx->fseEntropy, + dctx->ddictIsCold, nbSeq, + dctx->workspace, sizeof(dctx->workspace), + ZSTD_DCtx_get_bmi2(dctx)); + RETURN_ERROR_IF(ZSTD_isError(mlhSize), corruption_detected, "ZSTD_buildSeqTable failed"); + ip += mlhSize; + } + } + + return ip-istart; +} + + +typedef struct { + size_t litLength; + size_t matchLength; + size_t offset; +} seq_t; + +typedef struct { + size_t state; + const ZSTD_seqSymbol* table; +} ZSTD_fseState; + +typedef struct { + BIT_DStream_t DStream; + ZSTD_fseState stateLL; + ZSTD_fseState stateOffb; + ZSTD_fseState stateML; + size_t prevOffset[ZSTD_REP_NUM]; +} seqState_t; + +/*! ZSTD_overlapCopy8() : + * Copies 8 bytes from ip to op and updates op and ip where ip <= op. + * If the offset is < 8 then the offset is spread to at least 8 bytes. + * + * Precondition: *ip <= *op + * Postcondition: *op - *op >= 8 + */ +HINT_INLINE void ZSTD_overlapCopy8(BYTE** op, BYTE const** ip, size_t offset) { + assert(*ip <= *op); + if (offset < 8) { + /* close range match, overlap */ + static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */ + static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* subtracted */ + int const sub2 = dec64table[offset]; + (*op)[0] = (*ip)[0]; + (*op)[1] = (*ip)[1]; + (*op)[2] = (*ip)[2]; + (*op)[3] = (*ip)[3]; + *ip += dec32table[offset]; + ZSTD_copy4(*op+4, *ip); + *ip -= sub2; + } else { + ZSTD_copy8(*op, *ip); + } + *ip += 8; + *op += 8; + assert(*op - *ip >= 8); +} + +/*! ZSTD_safecopy() : + * Specialized version of memcpy() that is allowed to READ up to WILDCOPY_OVERLENGTH past the input buffer + * and write up to 16 bytes past oend_w (op >= oend_w is allowed). + * This function is only called in the uncommon case where the sequence is near the end of the block. It + * should be fast for a single long sequence, but can be slow for several short sequences. + * + * @param ovtype controls the overlap detection + * - ZSTD_no_overlap: The source and destination are guaranteed to be at least WILDCOPY_VECLEN bytes apart. + * - ZSTD_overlap_src_before_dst: The src and dst may overlap and may be any distance apart. + * The src buffer must be before the dst buffer. + */ +static void ZSTD_safecopy(BYTE* op, const BYTE* const oend_w, BYTE const* ip, ptrdiff_t length, ZSTD_overlap_e ovtype) { + ptrdiff_t const diff = op - ip; + BYTE* const oend = op + length; + + assert((ovtype == ZSTD_no_overlap && (diff <= -8 || diff >= 8 || op >= oend_w)) || + (ovtype == ZSTD_overlap_src_before_dst && diff >= 0)); + + if (length < 8) { + /* Handle short lengths. */ + while (op < oend) *op++ = *ip++; + return; + } + if (ovtype == ZSTD_overlap_src_before_dst) { + /* Copy 8 bytes and ensure the offset >= 8 when there can be overlap. */ + assert(length >= 8); + ZSTD_overlapCopy8(&op, &ip, diff); + length -= 8; + assert(op - ip >= 8); + assert(op <= oend); + } + + if (oend <= oend_w) { + /* No risk of overwrite. */ + ZSTD_wildcopy(op, ip, length, ovtype); + return; + } + if (op <= oend_w) { + /* Wildcopy until we get close to the end. */ + assert(oend > oend_w); + ZSTD_wildcopy(op, ip, oend_w - op, ovtype); + ip += oend_w - op; + op += oend_w - op; + } + /* Handle the leftovers. */ + while (op < oend) *op++ = *ip++; +} + +/* ZSTD_safecopyDstBeforeSrc(): + * This version allows overlap with dst before src, or handles the non-overlap case with dst after src + * Kept separate from more common ZSTD_safecopy case to avoid performance impact to the safecopy common case */ +static void ZSTD_safecopyDstBeforeSrc(BYTE* op, const BYTE* ip, ptrdiff_t length) { + ptrdiff_t const diff = op - ip; + BYTE* const oend = op + length; + + if (length < 8 || diff > -8) { + /* Handle short lengths, close overlaps, and dst not before src. */ + while (op < oend) *op++ = *ip++; + return; + } + + if (op <= oend - WILDCOPY_OVERLENGTH && diff < -WILDCOPY_VECLEN) { + ZSTD_wildcopy(op, ip, oend - WILDCOPY_OVERLENGTH - op, ZSTD_no_overlap); + ip += oend - WILDCOPY_OVERLENGTH - op; + op += oend - WILDCOPY_OVERLENGTH - op; + } + + /* Handle the leftovers. */ + while (op < oend) *op++ = *ip++; +} + +/* ZSTD_execSequenceEnd(): + * This version handles cases that are near the end of the output buffer. It requires + * more careful checks to make sure there is no overflow. By separating out these hard + * and unlikely cases, we can speed up the common cases. + * + * NOTE: This function needs to be fast for a single long sequence, but doesn't need + * to be optimized for many small sequences, since those fall into ZSTD_execSequence(). + */ +FORCE_NOINLINE +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +size_t ZSTD_execSequenceEnd(BYTE* op, + BYTE* const oend, seq_t sequence, + const BYTE** litPtr, const BYTE* const litLimit, + const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd) +{ + BYTE* const oLitEnd = op + sequence.litLength; + size_t const sequenceLength = sequence.litLength + sequence.matchLength; + const BYTE* const iLitEnd = *litPtr + sequence.litLength; + const BYTE* match = oLitEnd - sequence.offset; + BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH; + + /* bounds checks : careful of address space overflow in 32-bit mode */ + RETURN_ERROR_IF(sequenceLength > (size_t)(oend - op), dstSize_tooSmall, "last match must fit within dstBuffer"); + RETURN_ERROR_IF(sequence.litLength > (size_t)(litLimit - *litPtr), corruption_detected, "try to read beyond literal buffer"); + assert(op < op + sequenceLength); + assert(oLitEnd < op + sequenceLength); + + /* copy literals */ + ZSTD_safecopy(op, oend_w, *litPtr, sequence.litLength, ZSTD_no_overlap); + op = oLitEnd; + *litPtr = iLitEnd; + + /* copy Match */ + if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { + /* offset beyond prefix */ + RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected, ""); + match = dictEnd - (prefixStart - match); + if (match + sequence.matchLength <= dictEnd) { + ZSTD_memmove(oLitEnd, match, sequence.matchLength); + return sequenceLength; + } + /* span extDict & currentPrefixSegment */ + { size_t const length1 = dictEnd - match; + ZSTD_memmove(oLitEnd, match, length1); + op = oLitEnd + length1; + sequence.matchLength -= length1; + match = prefixStart; + } + } + ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst); + return sequenceLength; +} + +/* ZSTD_execSequenceEndSplitLitBuffer(): + * 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. + */ +FORCE_NOINLINE +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +size_t ZSTD_execSequenceEndSplitLitBuffer(BYTE* op, + BYTE* const oend, const BYTE* const oend_w, seq_t sequence, + const BYTE** litPtr, const BYTE* const litLimit, + const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd) +{ + BYTE* const oLitEnd = op + sequence.litLength; + size_t const sequenceLength = sequence.litLength + sequence.matchLength; + const BYTE* const iLitEnd = *litPtr + sequence.litLength; + const BYTE* match = oLitEnd - sequence.offset; + + + /* bounds checks : careful of address space overflow in 32-bit mode */ + RETURN_ERROR_IF(sequenceLength > (size_t)(oend - op), dstSize_tooSmall, "last match must fit within dstBuffer"); + RETURN_ERROR_IF(sequence.litLength > (size_t)(litLimit - *litPtr), corruption_detected, "try to read beyond literal buffer"); + assert(op < op + sequenceLength); + assert(oLitEnd < op + sequenceLength); + + /* copy literals */ + RETURN_ERROR_IF(op > *litPtr && op < *litPtr + sequence.litLength, dstSize_tooSmall, "output should not catch up to and overwrite literal buffer"); + ZSTD_safecopyDstBeforeSrc(op, *litPtr, sequence.litLength); + op = oLitEnd; + *litPtr = iLitEnd; + + /* copy Match */ + if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { + /* offset beyond prefix */ + RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected, ""); + match = dictEnd - (prefixStart - match); + if (match + sequence.matchLength <= dictEnd) { + ZSTD_memmove(oLitEnd, match, sequence.matchLength); + return sequenceLength; + } + /* span extDict & currentPrefixSegment */ + { size_t const length1 = dictEnd - match; + ZSTD_memmove(oLitEnd, match, length1); + op = oLitEnd + length1; + sequence.matchLength -= length1; + match = prefixStart; + } + } + ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst); + return sequenceLength; +} + +HINT_INLINE +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +size_t ZSTD_execSequence(BYTE* op, + BYTE* const oend, seq_t sequence, + const BYTE** litPtr, const BYTE* const litLimit, + const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd) +{ + BYTE* const oLitEnd = op + sequence.litLength; + size_t const sequenceLength = sequence.litLength + sequence.matchLength; + BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ + BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH; /* risk : address space underflow on oend=NULL */ + const BYTE* const iLitEnd = *litPtr + sequence.litLength; + const BYTE* match = oLitEnd - sequence.offset; + + assert(op != NULL /* Precondition */); + assert(oend_w < oend /* No underflow */); + +#if defined(__aarch64__) + /* prefetch sequence starting from match that will be used for copy later */ + PREFETCH_L1(match); +#endif + /* Handle edge cases in a slow path: + * - Read beyond end of literals + * - Match end is within WILDCOPY_OVERLIMIT of oend + * - 32-bit mode and the match length overflows + */ + if (UNLIKELY( + iLitEnd > litLimit || + oMatchEnd > oend_w || + (MEM_32bits() && (size_t)(oend - op) < sequenceLength + WILDCOPY_OVERLENGTH))) + return ZSTD_execSequenceEnd(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd); + + /* Assumptions (everything else goes into ZSTD_execSequenceEnd()) */ + assert(op <= oLitEnd /* No overflow */); + assert(oLitEnd < oMatchEnd /* Non-zero match & no overflow */); + assert(oMatchEnd <= oend /* No underflow */); + assert(iLitEnd <= litLimit /* Literal length is in bounds */); + assert(oLitEnd <= oend_w /* Can wildcopy literals */); + assert(oMatchEnd <= oend_w /* Can wildcopy matches */); + + /* Copy Literals: + * Split out litLength <= 16 since it is nearly always true. +1.6% on gcc-9. + * We likely don't need the full 32-byte wildcopy. + */ + assert(WILDCOPY_OVERLENGTH >= 16); + ZSTD_copy16(op, (*litPtr)); + if (UNLIKELY(sequence.litLength > 16)) { + ZSTD_wildcopy(op + 16, (*litPtr) + 16, sequence.litLength - 16, ZSTD_no_overlap); + } + op = oLitEnd; + *litPtr = iLitEnd; /* update for next sequence */ + + /* Copy Match */ + if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { + /* offset beyond prefix -> go into extDict */ + RETURN_ERROR_IF(UNLIKELY(sequence.offset > (size_t)(oLitEnd - virtualStart)), corruption_detected, ""); + match = dictEnd + (match - prefixStart); + if (match + sequence.matchLength <= dictEnd) { + ZSTD_memmove(oLitEnd, match, sequence.matchLength); + return sequenceLength; + } + /* span extDict & currentPrefixSegment */ + { size_t const length1 = dictEnd - match; + ZSTD_memmove(oLitEnd, match, length1); + op = oLitEnd + length1; + sequence.matchLength -= length1; + match = prefixStart; + } + } + /* Match within prefix of 1 or more bytes */ + assert(op <= oMatchEnd); + assert(oMatchEnd <= oend_w); + assert(match >= prefixStart); + assert(sequence.matchLength >= 1); + + /* Nearly all offsets are >= WILDCOPY_VECLEN bytes, which means we can use wildcopy + * without overlap checking. + */ + if (LIKELY(sequence.offset >= WILDCOPY_VECLEN)) { + /* We bet on a full wildcopy for matches, since we expect matches to be + * longer than literals (in general). In silesia, ~10% of matches are longer + * than 16 bytes. + */ + ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap); + return sequenceLength; + } + assert(sequence.offset < WILDCOPY_VECLEN); + + /* Copy 8 bytes and spread the offset to be >= 8. */ + ZSTD_overlapCopy8(&op, &match, sequence.offset); + + /* If the match length is > 8 bytes, then continue with the wildcopy. */ + if (sequence.matchLength > 8) { + assert(op < oMatchEnd); + ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength - 8, ZSTD_overlap_src_before_dst); + } + return sequenceLength; +} + +HINT_INLINE +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +size_t ZSTD_execSequenceSplitLitBuffer(BYTE* op, + BYTE* const oend, const BYTE* const oend_w, seq_t sequence, + const BYTE** litPtr, const BYTE* const litLimit, + const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd) +{ + BYTE* const oLitEnd = op + sequence.litLength; + size_t const sequenceLength = sequence.litLength + sequence.matchLength; + BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ + const BYTE* const iLitEnd = *litPtr + sequence.litLength; + const BYTE* match = oLitEnd - sequence.offset; + + assert(op != NULL /* Precondition */); + assert(oend_w < oend /* No underflow */); + /* Handle edge cases in a slow path: + * - Read beyond end of literals + * - Match end is within WILDCOPY_OVERLIMIT of oend + * - 32-bit mode and the match length overflows + */ + if (UNLIKELY( + iLitEnd > litLimit || + oMatchEnd > oend_w || + (MEM_32bits() && (size_t)(oend - op) < sequenceLength + WILDCOPY_OVERLENGTH))) + return ZSTD_execSequenceEndSplitLitBuffer(op, oend, oend_w, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd); + + /* Assumptions (everything else goes into ZSTD_execSequenceEnd()) */ + assert(op <= oLitEnd /* No overflow */); + assert(oLitEnd < oMatchEnd /* Non-zero match & no overflow */); + assert(oMatchEnd <= oend /* No underflow */); + assert(iLitEnd <= litLimit /* Literal length is in bounds */); + assert(oLitEnd <= oend_w /* Can wildcopy literals */); + assert(oMatchEnd <= oend_w /* Can wildcopy matches */); + + /* Copy Literals: + * Split out litLength <= 16 since it is nearly always true. +1.6% on gcc-9. + * We likely don't need the full 32-byte wildcopy. + */ + assert(WILDCOPY_OVERLENGTH >= 16); + ZSTD_copy16(op, (*litPtr)); + if (UNLIKELY(sequence.litLength > 16)) { + ZSTD_wildcopy(op+16, (*litPtr)+16, sequence.litLength-16, ZSTD_no_overlap); + } + op = oLitEnd; + *litPtr = iLitEnd; /* update for next sequence */ + + /* Copy Match */ + if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { + /* offset beyond prefix -> go into extDict */ + RETURN_ERROR_IF(UNLIKELY(sequence.offset > (size_t)(oLitEnd - virtualStart)), corruption_detected, ""); + match = dictEnd + (match - prefixStart); + if (match + sequence.matchLength <= dictEnd) { + ZSTD_memmove(oLitEnd, match, sequence.matchLength); + return sequenceLength; + } + /* span extDict & currentPrefixSegment */ + { size_t const length1 = dictEnd - match; + ZSTD_memmove(oLitEnd, match, length1); + op = oLitEnd + length1; + sequence.matchLength -= length1; + match = prefixStart; + } } + /* Match within prefix of 1 or more bytes */ + assert(op <= oMatchEnd); + assert(oMatchEnd <= oend_w); + assert(match >= prefixStart); + assert(sequence.matchLength >= 1); + + /* Nearly all offsets are >= WILDCOPY_VECLEN bytes, which means we can use wildcopy + * without overlap checking. + */ + if (LIKELY(sequence.offset >= WILDCOPY_VECLEN)) { + /* We bet on a full wildcopy for matches, since we expect matches to be + * longer than literals (in general). In silesia, ~10% of matches are longer + * than 16 bytes. + */ + ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap); + return sequenceLength; + } + assert(sequence.offset < WILDCOPY_VECLEN); + + /* Copy 8 bytes and spread the offset to be >= 8. */ + ZSTD_overlapCopy8(&op, &match, sequence.offset); + + /* If the match length is > 8 bytes, then continue with the wildcopy. */ + if (sequence.matchLength > 8) { + assert(op < oMatchEnd); + ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8, ZSTD_overlap_src_before_dst); + } + return sequenceLength; +} + + +static void +ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt) +{ + const void* ptr = dt; + const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr; + DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog); + DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits", + (U32)DStatePtr->state, DTableH->tableLog); + BIT_reloadDStream(bitD); + DStatePtr->table = dt + 1; +} + +FORCE_INLINE_TEMPLATE void +ZSTD_updateFseStateWithDInfo(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, U16 nextState, U32 nbBits) +{ + size_t const lowBits = BIT_readBits(bitD, nbBits); + DStatePtr->state = nextState + lowBits; +} + +/* We need to add at most (ZSTD_WINDOWLOG_MAX_32 - 1) bits to read the maximum + * offset bits. But we can only read at most STREAM_ACCUMULATOR_MIN_32 + * bits before reloading. This value is the maximum number of bytes we read + * after reloading when we are decoding long offsets. + */ +#define LONG_OFFSETS_MAX_EXTRA_BITS_32 \ + (ZSTD_WINDOWLOG_MAX_32 > STREAM_ACCUMULATOR_MIN_32 \ + ? ZSTD_WINDOWLOG_MAX_32 - STREAM_ACCUMULATOR_MIN_32 \ + : 0) + +typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e; + +/** + * ZSTD_decodeSequence(): + * @p longOffsets : tells the decoder to reload more bit while decoding large offsets + * only used in 32-bit mode + * @return : Sequence (litL + matchL + offset) + */ +FORCE_INLINE_TEMPLATE seq_t +ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets, const int isLastSeq) +{ + seq_t seq; + /* + * ZSTD_seqSymbol is a 64 bits wide structure. + * It can be loaded in one operation + * and its fields extracted by simply shifting or bit-extracting on aarch64. + * GCC doesn't recognize this and generates more unnecessary ldr/ldrb/ldrh + * operations that cause performance drop. This can be avoided by using this + * ZSTD_memcpy hack. + */ +#if defined(__aarch64__) && (defined(__GNUC__) && !defined(__clang__)) + ZSTD_seqSymbol llDInfoS, mlDInfoS, ofDInfoS; + ZSTD_seqSymbol* const llDInfo = &llDInfoS; + ZSTD_seqSymbol* const mlDInfo = &mlDInfoS; + ZSTD_seqSymbol* const ofDInfo = &ofDInfoS; + ZSTD_memcpy(llDInfo, seqState->stateLL.table + seqState->stateLL.state, sizeof(ZSTD_seqSymbol)); + ZSTD_memcpy(mlDInfo, seqState->stateML.table + seqState->stateML.state, sizeof(ZSTD_seqSymbol)); + ZSTD_memcpy(ofDInfo, seqState->stateOffb.table + seqState->stateOffb.state, sizeof(ZSTD_seqSymbol)); +#else + const ZSTD_seqSymbol* const llDInfo = seqState->stateLL.table + seqState->stateLL.state; + const ZSTD_seqSymbol* const mlDInfo = seqState->stateML.table + seqState->stateML.state; + const ZSTD_seqSymbol* const ofDInfo = seqState->stateOffb.table + seqState->stateOffb.state; +#endif + seq.matchLength = mlDInfo->baseValue; + seq.litLength = llDInfo->baseValue; + { U32 const ofBase = ofDInfo->baseValue; + BYTE const llBits = llDInfo->nbAdditionalBits; + BYTE const mlBits = mlDInfo->nbAdditionalBits; + BYTE const ofBits = ofDInfo->nbAdditionalBits; + BYTE const totalBits = llBits+mlBits+ofBits; + + U16 const llNext = llDInfo->nextState; + U16 const mlNext = mlDInfo->nextState; + U16 const ofNext = ofDInfo->nextState; + U32 const llnbBits = llDInfo->nbBits; + U32 const mlnbBits = mlDInfo->nbBits; + U32 const ofnbBits = ofDInfo->nbBits; + + assert(llBits <= MaxLLBits); + assert(mlBits <= MaxMLBits); + assert(ofBits <= MaxOff); + /* + * As gcc has better branch and block analyzers, sometimes it is only + * valuable to mark likeliness for clang, it gives around 3-4% of + * performance. + */ + + /* sequence */ + { size_t offset; + if (ofBits > 1) { + ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1); + ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5); + ZSTD_STATIC_ASSERT(STREAM_ACCUMULATOR_MIN_32 > LONG_OFFSETS_MAX_EXTRA_BITS_32); + ZSTD_STATIC_ASSERT(STREAM_ACCUMULATOR_MIN_32 - LONG_OFFSETS_MAX_EXTRA_BITS_32 >= MaxMLBits); + if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) { + /* Always read extra bits, this keeps the logic simple, + * avoids branches, and avoids accidentally reading 0 bits. + */ + U32 const extraBits = LONG_OFFSETS_MAX_EXTRA_BITS_32; + offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits); + BIT_reloadDStream(&seqState->DStream); + offset += BIT_readBitsFast(&seqState->DStream, extraBits); + } else { + offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ + if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); + } + seqState->prevOffset[2] = seqState->prevOffset[1]; + seqState->prevOffset[1] = seqState->prevOffset[0]; + seqState->prevOffset[0] = offset; + } else { + U32 const ll0 = (llDInfo->baseValue == 0); + if (LIKELY((ofBits == 0))) { + offset = seqState->prevOffset[ll0]; + seqState->prevOffset[1] = seqState->prevOffset[!ll0]; + seqState->prevOffset[0] = offset; + } else { + offset = ofBase + ll0 + BIT_readBitsFast(&seqState->DStream, 1); + { size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset]; + temp -= !temp; /* 0 is not valid: input corrupted => force offset to -1 => corruption detected at execSequence */ + if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1]; + seqState->prevOffset[1] = seqState->prevOffset[0]; + seqState->prevOffset[0] = offset = temp; + } } } + seq.offset = offset; + } + + if (mlBits > 0) + seq.matchLength += BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/); + + if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32)) + BIT_reloadDStream(&seqState->DStream); + if (MEM_64bits() && UNLIKELY(totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog))) + BIT_reloadDStream(&seqState->DStream); + /* Ensure there are enough bits to read the rest of data in 64-bit mode. */ + ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64); + + if (llBits > 0) + seq.litLength += BIT_readBitsFast(&seqState->DStream, llBits/*>0*/); + + if (MEM_32bits()) + BIT_reloadDStream(&seqState->DStream); + + DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u", + (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset); + + if (!isLastSeq) { + /* don't update FSE state for last Sequence */ + ZSTD_updateFseStateWithDInfo(&seqState->stateLL, &seqState->DStream, llNext, llnbBits); /* <= 9 bits */ + ZSTD_updateFseStateWithDInfo(&seqState->stateML, &seqState->DStream, mlNext, mlnbBits); /* <= 9 bits */ + if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ + ZSTD_updateFseStateWithDInfo(&seqState->stateOffb, &seqState->DStream, ofNext, ofnbBits); /* <= 8 bits */ + BIT_reloadDStream(&seqState->DStream); + } + } + + return seq; +} + +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) +#if DEBUGLEVEL >= 1 +static int ZSTD_dictionaryIsActive(ZSTD_DCtx const* dctx, BYTE const* prefixStart, BYTE const* oLitEnd) +{ + size_t const windowSize = dctx->fParams.windowSize; + /* No dictionary used. */ + if (dctx->dictContentEndForFuzzing == NULL) return 0; + /* Dictionary is our prefix. */ + if (prefixStart == dctx->dictContentBeginForFuzzing) return 1; + /* Dictionary is not our ext-dict. */ + if (dctx->dictEnd != dctx->dictContentEndForFuzzing) return 0; + /* Dictionary is not within our window size. */ + if ((size_t)(oLitEnd - prefixStart) >= windowSize) return 0; + /* Dictionary is active. */ + return 1; +} +#endif + +static void ZSTD_assertValidSequence( + ZSTD_DCtx const* dctx, + BYTE const* op, BYTE const* oend, + seq_t const seq, + BYTE const* prefixStart, BYTE const* virtualStart) +{ +#if DEBUGLEVEL >= 1 + if (dctx->isFrameDecompression) { + size_t const windowSize = dctx->fParams.windowSize; + size_t const sequenceSize = seq.litLength + seq.matchLength; + BYTE const* const oLitEnd = op + seq.litLength; + DEBUGLOG(6, "Checking sequence: litL=%u matchL=%u offset=%u", + (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset); + assert(op <= oend); + assert((size_t)(oend - op) >= sequenceSize); + assert(sequenceSize <= ZSTD_blockSizeMax(dctx)); + if (ZSTD_dictionaryIsActive(dctx, prefixStart, oLitEnd)) { + size_t const dictSize = (size_t)((char const*)dctx->dictContentEndForFuzzing - (char const*)dctx->dictContentBeginForFuzzing); + /* Offset must be within the dictionary. */ + assert(seq.offset <= (size_t)(oLitEnd - virtualStart)); + assert(seq.offset <= windowSize + dictSize); + } else { + /* Offset must be within our window. */ + assert(seq.offset <= windowSize); + } + } +#else + (void)dctx, (void)op, (void)oend, (void)seq, (void)prefixStart, (void)virtualStart; +#endif +} +#endif + +#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG + + +FORCE_INLINE_TEMPLATE size_t +DONT_VECTORIZE +ZSTD_decompressSequences_bodySplitLitBuffer( ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + const BYTE* ip = (const BYTE*)seqStart; + const BYTE* const iend = ip + seqSize; + BYTE* const ostart = (BYTE*)dst; + BYTE* const oend = ZSTD_maybeNullPtrAdd(ostart, maxDstSize); + BYTE* op = ostart; + const BYTE* litPtr = dctx->litPtr; + const BYTE* litBufferEnd = dctx->litBufferEnd; + const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart); + const BYTE* const vBase = (const BYTE*) (dctx->virtualStart); + const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd); + DEBUGLOG(5, "ZSTD_decompressSequences_bodySplitLitBuffer (%i seqs)", nbSeq); + + /* Literals are split between internal buffer & output buffer */ + if (nbSeq) { + seqState_t seqState; + dctx->fseEntropy = 1; + { U32 i; for (i=0; ientropy.rep[i]; } + RETURN_ERROR_IF( + ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)), + corruption_detected, ""); + ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); + ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); + ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); + assert(dst != NULL); + + ZSTD_STATIC_ASSERT( + BIT_DStream_unfinished < BIT_DStream_completed && + BIT_DStream_endOfBuffer < BIT_DStream_completed && + BIT_DStream_completed < BIT_DStream_overflow); + + /* decompress without overrunning litPtr begins */ + { seq_t sequence = {0,0,0}; /* some static analyzer believe that @sequence is not initialized (it necessarily is, since for(;;) loop as at least one iteration) */ + /* Align the decompression loop to 32 + 16 bytes. + * + * zstd compiled with gcc-9 on an Intel i9-9900k shows 10% decompression + * speed swings based on the alignment of the decompression loop. This + * performance swing is caused by parts of the decompression loop falling + * out of the DSB. The entire decompression loop should fit in the DSB, + * when it can't we get much worse performance. You can measure if you've + * hit the good case or the bad case with this perf command for some + * compressed file test.zst: + * + * perf stat -e cycles -e instructions -e idq.all_dsb_cycles_any_uops \ + * -e idq.all_mite_cycles_any_uops -- ./zstd -tq test.zst + * + * If you see most cycles served out of the MITE you've hit the bad case. + * If you see most cycles served out of the DSB you've hit the good case. + * If it is pretty even then you may be in an okay case. + * + * This issue has been reproduced on the following CPUs: + * - Kabylake: Macbook Pro (15-inch, 2019) 2.4 GHz Intel Core i9 + * Use Instruments->Counters to get DSB/MITE cycles. + * I never got performance swings, but I was able to + * go from the good case of mostly DSB to half of the + * cycles served from MITE. + * - Coffeelake: Intel i9-9900k + * - Coffeelake: Intel i7-9700k + * + * I haven't been able to reproduce the instability or DSB misses on any + * of the following CPUS: + * - Haswell + * - Broadwell: Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GH + * - Skylake + * + * Alignment is done for each of the three major decompression loops: + * - ZSTD_decompressSequences_bodySplitLitBuffer - presplit section of the literal buffer + * - ZSTD_decompressSequences_bodySplitLitBuffer - postsplit section of the literal buffer + * - ZSTD_decompressSequences_body + * Alignment choices are made to minimize large swings on bad cases and influence on performance + * from changes external to this code, rather than to overoptimize on the current commit. + * + * If you are seeing performance stability this script can help test. + * It tests on 4 commits in zstd where I saw performance change. + * + * https://gist.github.com/terrelln/9889fc06a423fd5ca6e99351564473f4 + */ +#if defined(__GNUC__) && defined(__x86_64__) + __asm__(".p2align 6"); +# if __GNUC__ >= 7 + /* good for gcc-7, gcc-9, and gcc-11 */ + __asm__("nop"); + __asm__(".p2align 5"); + __asm__("nop"); + __asm__(".p2align 4"); +# if __GNUC__ == 8 || __GNUC__ == 10 + /* good for gcc-8 and gcc-10 */ + __asm__("nop"); + __asm__(".p2align 3"); +# endif +# endif +#endif + + /* Handle the initial state where litBuffer is currently split between dst and litExtraBuffer */ + for ( ; nbSeq; nbSeq--) { + sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1); + if (litPtr + sequence.litLength > dctx->litBufferEnd) break; + { size_t const oneSeqSize = ZSTD_execSequenceSplitLitBuffer(op, oend, litPtr + sequence.litLength - WILDCOPY_OVERLENGTH, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd); +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) + assert(!ZSTD_isError(oneSeqSize)); + ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase); +#endif + if (UNLIKELY(ZSTD_isError(oneSeqSize))) + return oneSeqSize; + DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize); + op += oneSeqSize; + } } + DEBUGLOG(6, "reached: (litPtr + sequence.litLength > dctx->litBufferEnd)"); + + /* If there are more sequences, they will need to read literals from litExtraBuffer; copy over the remainder from dst and update litPtr and litEnd */ + if (nbSeq > 0) { + const size_t leftoverLit = dctx->litBufferEnd - litPtr; + DEBUGLOG(6, "There are %i sequences left, and %zu/%zu literals left in buffer", nbSeq, leftoverLit, sequence.litLength); + if (leftoverLit) { + RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer"); + ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit); + sequence.litLength -= leftoverLit; + op += leftoverLit; + } + litPtr = dctx->litExtraBuffer; + litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE; + dctx->litBufferLocation = ZSTD_not_in_dst; + { size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd); +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) + assert(!ZSTD_isError(oneSeqSize)); + ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase); +#endif + if (UNLIKELY(ZSTD_isError(oneSeqSize))) + return oneSeqSize; + DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize); + op += oneSeqSize; + } + nbSeq--; + } + } + + if (nbSeq > 0) { + /* there is remaining lit from extra buffer */ + +#if defined(__GNUC__) && defined(__x86_64__) + __asm__(".p2align 6"); + __asm__("nop"); +# if __GNUC__ != 7 + /* worse for gcc-7 better for gcc-8, gcc-9, and gcc-10 and clang */ + __asm__(".p2align 4"); + __asm__("nop"); + __asm__(".p2align 3"); +# elif __GNUC__ >= 11 + __asm__(".p2align 3"); +# else + __asm__(".p2align 5"); + __asm__("nop"); + __asm__(".p2align 3"); +# endif +#endif + + for ( ; nbSeq ; nbSeq--) { + seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1); + size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd); +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) + assert(!ZSTD_isError(oneSeqSize)); + ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase); +#endif + if (UNLIKELY(ZSTD_isError(oneSeqSize))) + return oneSeqSize; + DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize); + op += oneSeqSize; + } + } + + /* check if reached exact end */ + DEBUGLOG(5, "ZSTD_decompressSequences_bodySplitLitBuffer: after decode loop, remaining nbSeq : %i", nbSeq); + RETURN_ERROR_IF(nbSeq, corruption_detected, ""); + DEBUGLOG(5, "bitStream : start=%p, ptr=%p, bitsConsumed=%u", seqState.DStream.start, seqState.DStream.ptr, seqState.DStream.bitsConsumed); + RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, ""); + /* save reps for next block */ + { U32 i; for (i=0; ientropy.rep[i] = (U32)(seqState.prevOffset[i]); } + } + + /* last literal segment */ + if (dctx->litBufferLocation == ZSTD_split) { + /* split hasn't been reached yet, first get dst then copy litExtraBuffer */ + size_t const lastLLSize = (size_t)(litBufferEnd - litPtr); + DEBUGLOG(6, "copy last literals from segment : %u", (U32)lastLLSize); + RETURN_ERROR_IF(lastLLSize > (size_t)(oend - op), dstSize_tooSmall, ""); + if (op != NULL) { + ZSTD_memmove(op, litPtr, lastLLSize); + op += lastLLSize; + } + litPtr = dctx->litExtraBuffer; + litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE; + dctx->litBufferLocation = ZSTD_not_in_dst; + } + /* copy last literals from internal buffer */ + { size_t const lastLLSize = (size_t)(litBufferEnd - litPtr); + DEBUGLOG(6, "copy last literals from internal buffer : %u", (U32)lastLLSize); + RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, ""); + if (op != NULL) { + ZSTD_memcpy(op, litPtr, lastLLSize); + op += lastLLSize; + } } + + DEBUGLOG(6, "decoded block of size %u bytes", (U32)(op - ostart)); + return (size_t)(op - ostart); +} + +FORCE_INLINE_TEMPLATE size_t +DONT_VECTORIZE +ZSTD_decompressSequences_body(ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + const BYTE* ip = (const BYTE*)seqStart; + const BYTE* const iend = ip + seqSize; + BYTE* const ostart = (BYTE*)dst; + BYTE* const oend = dctx->litBufferLocation == ZSTD_not_in_dst ? ZSTD_maybeNullPtrAdd(ostart, maxDstSize) : dctx->litBuffer; + BYTE* op = ostart; + const BYTE* litPtr = dctx->litPtr; + const BYTE* const litEnd = litPtr + dctx->litSize; + const BYTE* const prefixStart = (const BYTE*)(dctx->prefixStart); + const BYTE* const vBase = (const BYTE*)(dctx->virtualStart); + const BYTE* const dictEnd = (const BYTE*)(dctx->dictEnd); + DEBUGLOG(5, "ZSTD_decompressSequences_body: nbSeq = %d", nbSeq); + + /* Regen sequences */ + if (nbSeq) { + seqState_t seqState; + dctx->fseEntropy = 1; + { U32 i; for (i = 0; i < ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; } + RETURN_ERROR_IF( + ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend - ip)), + corruption_detected, ""); + ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); + ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); + ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); + assert(dst != NULL); + +#if defined(__GNUC__) && defined(__x86_64__) + __asm__(".p2align 6"); + __asm__("nop"); +# if __GNUC__ >= 7 + __asm__(".p2align 5"); + __asm__("nop"); + __asm__(".p2align 3"); +# else + __asm__(".p2align 4"); + __asm__("nop"); + __asm__(".p2align 3"); +# endif +#endif + + for ( ; nbSeq ; nbSeq--) { + seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1); + size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd); +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) + assert(!ZSTD_isError(oneSeqSize)); + ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase); +#endif + if (UNLIKELY(ZSTD_isError(oneSeqSize))) + return oneSeqSize; + DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize); + op += oneSeqSize; + } + + /* check if reached exact end */ + assert(nbSeq == 0); + RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, ""); + /* save reps for next block */ + { U32 i; for (i=0; ientropy.rep[i] = (U32)(seqState.prevOffset[i]); } + } + + /* last literal segment */ + { size_t const lastLLSize = (size_t)(litEnd - litPtr); + DEBUGLOG(6, "copy last literals : %u", (U32)lastLLSize); + RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, ""); + if (op != NULL) { + ZSTD_memcpy(op, litPtr, lastLLSize); + op += lastLLSize; + } } + + DEBUGLOG(6, "decoded block of size %u bytes", (U32)(op - ostart)); + return (size_t)(op - ostart); +} + +static size_t +ZSTD_decompressSequences_default(ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} + +static size_t +ZSTD_decompressSequencesSplitLitBuffer_default(ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + return ZSTD_decompressSequences_bodySplitLitBuffer(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} +#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ + +#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT + +FORCE_INLINE_TEMPLATE + +size_t ZSTD_prefetchMatch(size_t prefetchPos, seq_t const sequence, + const BYTE* const prefixStart, const BYTE* const dictEnd) +{ + prefetchPos += sequence.litLength; + { const BYTE* const matchBase = (sequence.offset > prefetchPos) ? dictEnd : prefixStart; + /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted. + * No consequence though : memory address is only used for prefetching, not for dereferencing */ + const BYTE* const match = ZSTD_wrappedPtrSub(ZSTD_wrappedPtrAdd(matchBase, prefetchPos), sequence.offset); + PREFETCH_L1(match); PREFETCH_L1(match+CACHELINE_SIZE); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */ + } + return prefetchPos + sequence.matchLength; +} + +/* This decoding function employs prefetching + * to reduce latency impact of cache misses. + * It's generally employed when block contains a significant portion of long-distance matches + * or when coupled with a "cold" dictionary */ +FORCE_INLINE_TEMPLATE size_t +ZSTD_decompressSequencesLong_body( + ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + const BYTE* ip = (const BYTE*)seqStart; + const BYTE* const iend = ip + seqSize; + BYTE* const ostart = (BYTE*)dst; + BYTE* const oend = dctx->litBufferLocation == ZSTD_in_dst ? dctx->litBuffer : ZSTD_maybeNullPtrAdd(ostart, maxDstSize); + BYTE* op = ostart; + const BYTE* litPtr = dctx->litPtr; + const BYTE* litBufferEnd = dctx->litBufferEnd; + const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart); + const BYTE* const dictStart = (const BYTE*) (dctx->virtualStart); + const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd); + + /* Regen sequences */ + if (nbSeq) { +#define STORED_SEQS 8 +#define STORED_SEQS_MASK (STORED_SEQS-1) +#define ADVANCED_SEQS STORED_SEQS + seq_t sequences[STORED_SEQS]; + int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS); + seqState_t seqState; + int seqNb; + size_t prefetchPos = (size_t)(op-prefixStart); /* track position relative to prefixStart */ + + dctx->fseEntropy = 1; + { int i; for (i=0; ientropy.rep[i]; } + assert(dst != NULL); + assert(iend >= ip); + RETURN_ERROR_IF( + ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)), + corruption_detected, ""); + ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); + ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); + ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); + + /* prepare in advance */ + for (seqNb=0; seqNblitBufferLocation == ZSTD_split && litPtr + sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength > dctx->litBufferEnd) { + /* lit buffer is reaching split point, empty out the first buffer and transition to litExtraBuffer */ + const size_t leftoverLit = dctx->litBufferEnd - litPtr; + if (leftoverLit) + { + RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer"); + ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit); + sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength -= leftoverLit; + op += leftoverLit; + } + litPtr = dctx->litExtraBuffer; + litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE; + dctx->litBufferLocation = ZSTD_not_in_dst; + { size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd); +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) + assert(!ZSTD_isError(oneSeqSize)); + ZSTD_assertValidSequence(dctx, op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], prefixStart, dictStart); +#endif + if (ZSTD_isError(oneSeqSize)) return oneSeqSize; + + prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd); + sequences[seqNb & STORED_SEQS_MASK] = sequence; + op += oneSeqSize; + } } + else + { + /* lit buffer is either wholly contained in first or second split, or not split at all*/ + size_t const oneSeqSize = dctx->litBufferLocation == ZSTD_split ? + 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) : + ZSTD_execSequence(op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd); +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) + assert(!ZSTD_isError(oneSeqSize)); + ZSTD_assertValidSequence(dctx, op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], prefixStart, dictStart); +#endif + if (ZSTD_isError(oneSeqSize)) return oneSeqSize; + + prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd); + sequences[seqNb & STORED_SEQS_MASK] = sequence; + op += oneSeqSize; + } + } + RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, ""); + + /* finish queue */ + seqNb -= seqAdvance; + for ( ; seqNblitBufferLocation == ZSTD_split && litPtr + sequence->litLength > dctx->litBufferEnd) { + const size_t leftoverLit = dctx->litBufferEnd - litPtr; + if (leftoverLit) { + RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer"); + ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit); + sequence->litLength -= leftoverLit; + op += leftoverLit; + } + litPtr = dctx->litExtraBuffer; + litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE; + dctx->litBufferLocation = ZSTD_not_in_dst; + { size_t const oneSeqSize = ZSTD_execSequence(op, oend, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd); +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) + assert(!ZSTD_isError(oneSeqSize)); + ZSTD_assertValidSequence(dctx, op, oend, sequences[seqNb&STORED_SEQS_MASK], prefixStart, dictStart); +#endif + if (ZSTD_isError(oneSeqSize)) return oneSeqSize; + op += oneSeqSize; + } + } + else + { + size_t const oneSeqSize = dctx->litBufferLocation == ZSTD_split ? + ZSTD_execSequenceSplitLitBuffer(op, oend, litPtr + sequence->litLength - WILDCOPY_OVERLENGTH, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd) : + ZSTD_execSequence(op, oend, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd); +#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) + assert(!ZSTD_isError(oneSeqSize)); + ZSTD_assertValidSequence(dctx, op, oend, sequences[seqNb&STORED_SEQS_MASK], prefixStart, dictStart); +#endif + if (ZSTD_isError(oneSeqSize)) return oneSeqSize; + op += oneSeqSize; + } + } + + /* save reps for next block */ + { U32 i; for (i=0; ientropy.rep[i] = (U32)(seqState.prevOffset[i]); } + } + + /* last literal segment */ + if (dctx->litBufferLocation == ZSTD_split) { /* first deplete literal buffer in dst, then copy litExtraBuffer */ + size_t const lastLLSize = litBufferEnd - litPtr; + RETURN_ERROR_IF(lastLLSize > (size_t)(oend - op), dstSize_tooSmall, ""); + if (op != NULL) { + ZSTD_memmove(op, litPtr, lastLLSize); + op += lastLLSize; + } + litPtr = dctx->litExtraBuffer; + litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE; + } + { size_t const lastLLSize = litBufferEnd - litPtr; + RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, ""); + if (op != NULL) { + ZSTD_memmove(op, litPtr, lastLLSize); + op += lastLLSize; + } + } + + return (size_t)(op - ostart); +} + +static size_t +ZSTD_decompressSequencesLong_default(ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} +#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ + + + +#if DYNAMIC_BMI2 + +#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG +static BMI2_TARGET_ATTRIBUTE size_t +DONT_VECTORIZE +ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} +static BMI2_TARGET_ATTRIBUTE size_t +DONT_VECTORIZE +ZSTD_decompressSequencesSplitLitBuffer_bmi2(ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + return ZSTD_decompressSequences_bodySplitLitBuffer(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} +#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ + +#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT +static BMI2_TARGET_ATTRIBUTE size_t +ZSTD_decompressSequencesLong_bmi2(ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} +#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ + +#endif /* DYNAMIC_BMI2 */ + +typedef size_t (*ZSTD_decompressSequences_t)( + ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset); + +#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG +static size_t +ZSTD_decompressSequences(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + DEBUGLOG(5, "ZSTD_decompressSequences"); +#if DYNAMIC_BMI2 + if (ZSTD_DCtx_get_bmi2(dctx)) { + return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); + } +#endif + return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} +static size_t +ZSTD_decompressSequencesSplitLitBuffer(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + DEBUGLOG(5, "ZSTD_decompressSequencesSplitLitBuffer"); +#if DYNAMIC_BMI2 + if (ZSTD_DCtx_get_bmi2(dctx)) { + return ZSTD_decompressSequencesSplitLitBuffer_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); + } +#endif + return ZSTD_decompressSequencesSplitLitBuffer_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} +#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ + + +#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT +/* ZSTD_decompressSequencesLong() : + * decompression function triggered when a minimum share of offsets is considered "long", + * aka out of cache. + * note : "long" definition seems overloaded here, sometimes meaning "wider than bitstream register", and sometimes meaning "farther than memory cache distance". + * This function will try to mitigate main memory latency through the use of prefetching */ +static size_t +ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, int nbSeq, + const ZSTD_longOffset_e isLongOffset) +{ + DEBUGLOG(5, "ZSTD_decompressSequencesLong"); +#if DYNAMIC_BMI2 + if (ZSTD_DCtx_get_bmi2(dctx)) { + return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); + } +#endif + return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); +} +#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ + + +/** + * @returns The total size of the history referenceable by zstd, including + * both the prefix and the extDict. At @p op any offset larger than this + * is invalid. + */ +static size_t ZSTD_totalHistorySize(BYTE* op, BYTE const* virtualStart) +{ + return (size_t)(op - virtualStart); +} + +typedef struct { + unsigned longOffsetShare; + unsigned maxNbAdditionalBits; +} ZSTD_OffsetInfo; + +/* ZSTD_getOffsetInfo() : + * condition : offTable must be valid + * @return : "share" of long offsets (arbitrarily defined as > (1<<23)) + * compared to maximum possible of (1< 22) info.longOffsetShare += 1; + } + + assert(tableLog <= OffFSELog); + info.longOffsetShare <<= (OffFSELog - tableLog); /* scale to OffFSELog */ + } + + return info; +} + +/** + * @returns The maximum offset we can decode in one read of our bitstream, without + * reloading more bits in the middle of the offset bits read. Any offsets larger + * than this must use the long offset decoder. + */ +static size_t ZSTD_maxShortOffset(void) +{ + if (MEM_64bits()) { + /* We can decode any offset without reloading bits. + * This might change if the max window size grows. + */ + ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX <= 31); + return (size_t)-1; + } else { + /* The maximum offBase is (1 << (STREAM_ACCUMULATOR_MIN + 1)) - 1. + * This offBase would require STREAM_ACCUMULATOR_MIN extra bits. + * Then we have to subtract ZSTD_REP_NUM to get the maximum possible offset. + */ + size_t const maxOffbase = ((size_t)1 << (STREAM_ACCUMULATOR_MIN + 1)) - 1; + size_t const maxOffset = maxOffbase - ZSTD_REP_NUM; + assert(ZSTD_highbit32((U32)maxOffbase) == STREAM_ACCUMULATOR_MIN); + return maxOffset; + } +} + +size_t +ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, const streaming_operation streaming) +{ /* blockType == blockCompressed */ + const BYTE* ip = (const BYTE*)src; + DEBUGLOG(5, "ZSTD_decompressBlock_internal (cSize : %u)", (unsigned)srcSize); + + /* Note : the wording of the specification + * allows compressed block to be sized exactly ZSTD_blockSizeMax(dctx). + * This generally does not happen, as it makes little sense, + * since an uncompressed block would feature same size and have no decompression cost. + * Also, note that decoder from reference libzstd before < v1.5.4 + * would consider this edge case as an error. + * As a consequence, avoid generating compressed blocks of size ZSTD_blockSizeMax(dctx) + * for broader compatibility with the deployed ecosystem of zstd decoders */ + RETURN_ERROR_IF(srcSize > ZSTD_blockSizeMax(dctx), srcSize_wrong, ""); + + /* Decode literals section */ + { size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize, dst, dstCapacity, streaming); + DEBUGLOG(5, "ZSTD_decodeLiteralsBlock : cSize=%u, nbLiterals=%zu", (U32)litCSize, dctx->litSize); + if (ZSTD_isError(litCSize)) return litCSize; + ip += litCSize; + srcSize -= litCSize; + } + + /* Build Decoding Tables */ + { + /* Compute the maximum block size, which must also work when !frame and fParams are unset. + * Additionally, take the min with dstCapacity to ensure that the totalHistorySize fits in a size_t. + */ + size_t const blockSizeMax = MIN(dstCapacity, ZSTD_blockSizeMax(dctx)); + size_t const totalHistorySize = ZSTD_totalHistorySize(ZSTD_maybeNullPtrAdd((BYTE*)dst, blockSizeMax), (BYTE const*)dctx->virtualStart); + /* isLongOffset must be true if there are long offsets. + * Offsets are long if they are larger than ZSTD_maxShortOffset(). + * We don't expect that to be the case in 64-bit mode. + * + * We check here to see if our history is large enough to allow long offsets. + * If it isn't, then we can't possible have (valid) long offsets. If the offset + * is invalid, then it is okay to read it incorrectly. + * + * If isLongOffsets is true, then we will later check our decoding table to see + * if it is even possible to generate long offsets. + */ + ZSTD_longOffset_e isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (totalHistorySize > ZSTD_maxShortOffset())); + /* These macros control at build-time which decompressor implementation + * we use. If neither is defined, we do some inspection and dispatch at + * runtime. + */ +#if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ + !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) + int usePrefetchDecoder = dctx->ddictIsCold; +#else + /* Set to 1 to avoid computing offset info if we don't need to. + * Otherwise this value is ignored. + */ + int usePrefetchDecoder = 1; +#endif + int nbSeq; + size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize); + if (ZSTD_isError(seqHSize)) return seqHSize; + ip += seqHSize; + srcSize -= seqHSize; + + RETURN_ERROR_IF((dst == NULL || dstCapacity == 0) && nbSeq > 0, dstSize_tooSmall, "NULL not handled"); + RETURN_ERROR_IF(MEM_64bits() && sizeof(size_t) == sizeof(void*) && (size_t)(-1) - (size_t)dst < (size_t)(1 << 20), dstSize_tooSmall, + "invalid dst"); + + /* If we could potentially have long offsets, or we might want to use the prefetch decoder, + * compute information about the share of long offsets, and the maximum nbAdditionalBits. + * NOTE: could probably use a larger nbSeq limit + */ + if (isLongOffset || (!usePrefetchDecoder && (totalHistorySize > (1u << 24)) && (nbSeq > 8))) { + ZSTD_OffsetInfo const info = ZSTD_getOffsetInfo(dctx->OFTptr, nbSeq); + if (isLongOffset && info.maxNbAdditionalBits <= STREAM_ACCUMULATOR_MIN) { + /* If isLongOffset, but the maximum number of additional bits that we see in our table is small + * enough, then we know it is impossible to have too long an offset in this block, so we can + * use the regular offset decoder. + */ + isLongOffset = ZSTD_lo_isRegularOffset; + } + if (!usePrefetchDecoder) { + U32 const minShare = MEM_64bits() ? 7 : 20; /* heuristic values, correspond to 2.73% and 7.81% */ + usePrefetchDecoder = (info.longOffsetShare >= minShare); + } + } + + dctx->ddictIsCold = 0; + +#if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ + !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) + if (usePrefetchDecoder) { +#else + (void)usePrefetchDecoder; + { +#endif +#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT + return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); +#endif + } + +#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG + /* else */ + if (dctx->litBufferLocation == ZSTD_split) + return ZSTD_decompressSequencesSplitLitBuffer(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); + else + return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); +#endif + } +} + + +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize) +{ + if (dst != dctx->previousDstEnd && dstSize > 0) { /* not contiguous */ + dctx->dictEnd = dctx->previousDstEnd; + dctx->virtualStart = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart)); + dctx->prefixStart = dst; + dctx->previousDstEnd = dst; + } +} + + +size_t ZSTD_decompressBlock_deprecated(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize) +{ + size_t dSize; + dctx->isFrameDecompression = 0; + ZSTD_checkContinuity(dctx, dst, dstCapacity); + dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, not_streaming); + FORWARD_IF_ERROR(dSize, ""); + dctx->previousDstEnd = (char*)dst + dSize; + return dSize; +} + + +/* NOTE: Must just wrap ZSTD_decompressBlock_deprecated() */ +size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize) +{ + return ZSTD_decompressBlock_deprecated(dctx, dst, dstCapacity, src, srcSize); +} diff --git a/third_party/zstd/lib/decompress/zstd_decompress_block.h b/third_party/zstd/lib/decompress/zstd_decompress_block.h new file mode 100644 index 0000000000..ab152404ba --- /dev/null +++ b/third_party/zstd/lib/decompress/zstd_decompress_block.h @@ -0,0 +1,73 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + + +#ifndef ZSTD_DEC_BLOCK_H +#define ZSTD_DEC_BLOCK_H + +/*-******************************************************* + * Dependencies + *********************************************************/ +#include "../common/zstd_deps.h" /* size_t */ +#include "../zstd.h" /* DCtx, and some public functions */ +#include "../common/zstd_internal.h" /* blockProperties_t, and some public functions */ +#include "zstd_decompress_internal.h" /* ZSTD_seqSymbol */ + + +/* === Prototypes === */ + +/* note: prototypes already published within `zstd.h` : + * ZSTD_decompressBlock() + */ + +/* note: prototypes already published within `zstd_internal.h` : + * ZSTD_getcBlockSize() + * ZSTD_decodeSeqHeaders() + */ + + + /* Streaming state is used to inform allocation of the literal buffer */ +typedef enum { + not_streaming = 0, + is_streaming = 1 +} streaming_operation; + +/* ZSTD_decompressBlock_internal() : + * decompress block, starting at `src`, + * into destination buffer `dst`. + * @return : decompressed block size, + * or an error code (which can be tested using ZSTD_isError()) + */ +size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, const streaming_operation streaming); + +/* ZSTD_buildFSETable() : + * generate FSE decoding table for one symbol (ll, ml or off) + * this function must be called with valid parameters only + * (dt is large enough, normalizedCounter distribution total is a power of 2, max is within range, etc.) + * in which case it cannot fail. + * The workspace must be 4-byte aligned and at least ZSTD_BUILD_FSE_TABLE_WKSP_SIZE bytes, which is + * defined in zstd_decompress_internal.h. + * Internal use only. + */ +void ZSTD_buildFSETable(ZSTD_seqSymbol* dt, + const short* normalizedCounter, unsigned maxSymbolValue, + const U32* baseValue, const U8* nbAdditionalBits, + unsigned tableLog, void* wksp, size_t wkspSize, + int bmi2); + +/* Internal definition of ZSTD_decompressBlock() to avoid deprecation warnings. */ +size_t ZSTD_decompressBlock_deprecated(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize); + + +#endif /* ZSTD_DEC_BLOCK_H */ diff --git a/third_party/zstd/lib/decompress/zstd_decompress_internal.h b/third_party/zstd/lib/decompress/zstd_decompress_internal.h new file mode 100644 index 0000000000..83a7a0115f --- /dev/null +++ b/third_party/zstd/lib/decompress/zstd_decompress_internal.h @@ -0,0 +1,240 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + + +/* zstd_decompress_internal: + * objects and definitions shared within lib/decompress modules */ + + #ifndef ZSTD_DECOMPRESS_INTERNAL_H + #define ZSTD_DECOMPRESS_INTERNAL_H + + +/*-******************************************************* + * Dependencies + *********************************************************/ +#include "../common/mem.h" /* BYTE, U16, U32 */ +#include "../common/zstd_internal.h" /* constants : MaxLL, MaxML, MaxOff, LLFSELog, etc. */ + + + +/*-******************************************************* + * Constants + *********************************************************/ +static UNUSED_ATTR const U32 LL_base[MaxLL+1] = { + 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 18, 20, 22, 24, 28, 32, 40, + 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, + 0x2000, 0x4000, 0x8000, 0x10000 }; + +static UNUSED_ATTR const U32 OF_base[MaxOff+1] = { + 0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D, + 0xFD, 0x1FD, 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD, + 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD, + 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD }; + +static UNUSED_ATTR const U8 OF_bits[MaxOff+1] = { + 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 17, 18, 19, 20, 21, 22, 23, + 24, 25, 26, 27, 28, 29, 30, 31 }; + +static UNUSED_ATTR const U32 ML_base[MaxML+1] = { + 3, 4, 5, 6, 7, 8, 9, 10, + 11, 12, 13, 14, 15, 16, 17, 18, + 19, 20, 21, 22, 23, 24, 25, 26, + 27, 28, 29, 30, 31, 32, 33, 34, + 35, 37, 39, 41, 43, 47, 51, 59, + 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803, + 0x1003, 0x2003, 0x4003, 0x8003, 0x10003 }; + + +/*-******************************************************* + * Decompression types + *********************************************************/ + typedef struct { + U32 fastMode; + U32 tableLog; + } ZSTD_seqSymbol_header; + + typedef struct { + U16 nextState; + BYTE nbAdditionalBits; + BYTE nbBits; + U32 baseValue; + } ZSTD_seqSymbol; + + #define SEQSYMBOL_TABLE_SIZE(log) (1 + (1 << (log))) + +#define ZSTD_BUILD_FSE_TABLE_WKSP_SIZE (sizeof(S16) * (MaxSeq + 1) + (1u << MaxFSELog) + sizeof(U64)) +#define ZSTD_BUILD_FSE_TABLE_WKSP_SIZE_U32 ((ZSTD_BUILD_FSE_TABLE_WKSP_SIZE + sizeof(U32) - 1) / sizeof(U32)) +#define ZSTD_HUFFDTABLE_CAPACITY_LOG 12 + +typedef struct { + ZSTD_seqSymbol LLTable[SEQSYMBOL_TABLE_SIZE(LLFSELog)]; /* Note : Space reserved for FSE Tables */ + ZSTD_seqSymbol OFTable[SEQSYMBOL_TABLE_SIZE(OffFSELog)]; /* is also used as temporary workspace while building hufTable during DDict creation */ + ZSTD_seqSymbol MLTable[SEQSYMBOL_TABLE_SIZE(MLFSELog)]; /* and therefore must be at least HUF_DECOMPRESS_WORKSPACE_SIZE large */ + HUF_DTable hufTable[HUF_DTABLE_SIZE(ZSTD_HUFFDTABLE_CAPACITY_LOG)]; /* can accommodate HUF_decompress4X */ + U32 rep[ZSTD_REP_NUM]; + U32 workspace[ZSTD_BUILD_FSE_TABLE_WKSP_SIZE_U32]; +} ZSTD_entropyDTables_t; + +typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader, + ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock, + ZSTDds_decompressLastBlock, ZSTDds_checkChecksum, + ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage; + +typedef enum { zdss_init=0, zdss_loadHeader, + zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage; + +typedef enum { + ZSTD_use_indefinitely = -1, /* Use the dictionary indefinitely */ + ZSTD_dont_use = 0, /* Do not use the dictionary (if one exists free it) */ + ZSTD_use_once = 1 /* Use the dictionary once and set to ZSTD_dont_use */ +} ZSTD_dictUses_e; + +/* Hashset for storing references to multiple ZSTD_DDict within ZSTD_DCtx */ +typedef struct { + const ZSTD_DDict** ddictPtrTable; + size_t ddictPtrTableSize; + size_t ddictPtrCount; +} ZSTD_DDictHashSet; + +#ifndef ZSTD_DECODER_INTERNAL_BUFFER +# define ZSTD_DECODER_INTERNAL_BUFFER (1 << 16) +#endif + +#define ZSTD_LBMIN 64 +#define ZSTD_LBMAX (128 << 10) + +/* extra buffer, compensates when dst is not large enough to store litBuffer */ +#define ZSTD_LITBUFFEREXTRASIZE BOUNDED(ZSTD_LBMIN, ZSTD_DECODER_INTERNAL_BUFFER, ZSTD_LBMAX) + +typedef enum { + ZSTD_not_in_dst = 0, /* Stored entirely within litExtraBuffer */ + ZSTD_in_dst = 1, /* Stored entirely within dst (in memory after current output write) */ + ZSTD_split = 2 /* Split between litExtraBuffer and dst */ +} ZSTD_litLocation_e; + +struct ZSTD_DCtx_s +{ + const ZSTD_seqSymbol* LLTptr; + const ZSTD_seqSymbol* MLTptr; + const ZSTD_seqSymbol* OFTptr; + const HUF_DTable* HUFptr; + ZSTD_entropyDTables_t entropy; + U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32]; /* space needed when building huffman tables */ + const void* previousDstEnd; /* detect continuity */ + const void* prefixStart; /* start of current segment */ + const void* virtualStart; /* virtual start of previous segment if it was just before current one */ + const void* dictEnd; /* end of previous segment */ + size_t expected; + ZSTD_frameHeader fParams; + U64 processedCSize; + U64 decodedSize; + blockType_e bType; /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */ + ZSTD_dStage stage; + U32 litEntropy; + U32 fseEntropy; + XXH64_state_t xxhState; + size_t headerSize; + ZSTD_format_e format; + ZSTD_forceIgnoreChecksum_e forceIgnoreChecksum; /* User specified: if == 1, will ignore checksums in compressed frame. Default == 0 */ + U32 validateChecksum; /* if == 1, will validate checksum. Is == 1 if (fParams.checksumFlag == 1) and (forceIgnoreChecksum == 0). */ + const BYTE* litPtr; + ZSTD_customMem customMem; + size_t litSize; + size_t rleSize; + size_t staticSize; + int isFrameDecompression; +#if DYNAMIC_BMI2 != 0 + int bmi2; /* == 1 if the CPU supports BMI2 and 0 otherwise. CPU support is determined dynamically once per context lifetime. */ +#endif + + /* dictionary */ + ZSTD_DDict* ddictLocal; + const ZSTD_DDict* ddict; /* set by ZSTD_initDStream_usingDDict(), or ZSTD_DCtx_refDDict() */ + U32 dictID; + int ddictIsCold; /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */ + ZSTD_dictUses_e dictUses; + ZSTD_DDictHashSet* ddictSet; /* Hash set for multiple ddicts */ + ZSTD_refMultipleDDicts_e refMultipleDDicts; /* User specified: if == 1, will allow references to multiple DDicts. Default == 0 (disabled) */ + int disableHufAsm; + int maxBlockSizeParam; + + /* streaming */ + ZSTD_dStreamStage streamStage; + char* inBuff; + size_t inBuffSize; + size_t inPos; + size_t maxWindowSize; + char* outBuff; + size_t outBuffSize; + size_t outStart; + size_t outEnd; + size_t lhSize; +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) + void* legacyContext; + U32 previousLegacyVersion; + U32 legacyVersion; +#endif + U32 hostageByte; + int noForwardProgress; + ZSTD_bufferMode_e outBufferMode; + ZSTD_outBuffer expectedOutBuffer; + + /* workspace */ + BYTE* litBuffer; + const BYTE* litBufferEnd; + ZSTD_litLocation_e litBufferLocation; + BYTE litExtraBuffer[ZSTD_LITBUFFEREXTRASIZE + WILDCOPY_OVERLENGTH]; /* literal buffer can be split between storage within dst and within this scratch buffer */ + BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; + + size_t oversizedDuration; + +#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + void const* dictContentBeginForFuzzing; + void const* dictContentEndForFuzzing; +#endif + + /* Tracing */ +#if ZSTD_TRACE + ZSTD_TraceCtx traceCtx; +#endif +}; /* typedef'd to ZSTD_DCtx within "zstd.h" */ + +MEM_STATIC int ZSTD_DCtx_get_bmi2(const struct ZSTD_DCtx_s *dctx) { +#if DYNAMIC_BMI2 != 0 + return dctx->bmi2; +#else + (void)dctx; + return 0; +#endif +} + +/*-******************************************************* + * Shared internal functions + *********************************************************/ + +/*! ZSTD_loadDEntropy() : + * dict : must point at beginning of a valid zstd dictionary. + * @return : size of dictionary header (size of magic number + dict ID + entropy tables) */ +size_t ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy, + const void* const dict, size_t const dictSize); + +/*! ZSTD_checkContinuity() : + * check if next `dst` follows previous position, where decompression ended. + * If yes, do nothing (continue on current segment). + * If not, classify previous segment as "external dictionary", and start a new segment. + * This function cannot fail. */ +void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize); + + +#endif /* ZSTD_DECOMPRESS_INTERNAL_H */ -- cgit v1.2.3