From 24488e4eaa06edd3aee8141fc41db70cece7b167 Mon Sep 17 00:00:00 2001 From: ddidderr Date: Sat, 11 Jul 2026 14:25:23 +0200 Subject: [PATCH] feat(rust): port legacy v0.1 decoder Port lib/legacy/zstd_v01.c (the frozen zstd v0.1 decoder) to rust/src/legacy/zstd_v01.rs as the first legacy-format port on the new scaffolding, and reduce the C file to a declaration-only shim that keeps its header includes for configuration and platform preprocessor behavior. Frozen-decoder policy: zstd_v01.c embeds its own v0.1-era FSE and Huff0 snapshot, distinct from every other release. The Rust port is a line-by-line translation with the same table layouts (FSE_DTable as a u32 header word plus packed newState/symbol/nbBits entries, the Huff0 u16 DTable with byte/nbBits pairs), the same arithmetic including wrap-around and pointer-comparison quirks (e.g. the offset-vs-base address check in ZSTD_execSequence), the same internal FSE error space (size_t)-1..-7, and the same public ZSTD error codes. It reuses no modern Rust entropy module; its only crate dependency is `errors`, matching the C file's error_private.h include. The 32-bit-only reload points are kept as compile-time conditions on usize::BITS. Symbol takeover boundary: all nine ZSTDv01_* entry points from zstd_v01.h now come from Rust as context-free #[no_mangle] extern "C" functions (isError, decompress, decompressDCtx, findFrameSizeInfoLegacy, createDCtx, freeDCtx, resetDCtx, nextSrcSizeToDecompress, decompressContinue). zstd_legacy.h only uses the first four for v0.1; streaming for v0.1-v0.3 intentionally returns version_unsupported there, unchanged. The ZSTDv01_Dctx struct definition moves entirely into Rust: C code only ever holds an opaque pointer (zstd_v01.h forward-declares the type), and the context is malloc/free-allocated exactly like the C version so create/free may pair across the language boundary. Byte-identity verification against the pristine pre-migration C build (f8745da6, pure C, ZSTD_LEGACY_SUPPORT=1): - Real v0.1 frames were generated by building the v0.1.0 git tag and compressing text, random, and 426 KB multi-block inputs. A one-shot ZSTD_decompress harness linked once against the pristine C libzstd.a and once against the Rust-backed libzstd.a produced bit-identical outputs for all frames. - A direct ZSTDv01_* probe (one-shot decode, dst-too-small, truncated input, bad magic, findFrameSizeInfoLegacy, and the streaming continue loop) printed identical results, including exact error codes (-70 dstSize_tooSmall, -72 srcSize_wrong, -10 prefix_unknown) and identical dBound values. - zstd -l -v on v0.1 files matches the pristine binary; CLI streaming decode of v0.1 fails with the same "Version not supported" in both, by design of zstd_legacy.h. Unit tests embed three v0.1.0-generated fixtures (entropy-coded, raw-block, and four-block frames) plus the truncation, bad-magic, small-destination, and streaming-API cases, all asserting the exact C error codes above. Note that `make -C tests test-legacy` only covers v0.4+ frames, so the embedded fixtures and the harness comparison are the actual v0.1 coverage. Test plan: - cd rust && cargo fmt --check && cargo clippy --all-targets --features legacy-v01 -- -D warnings && cargo test --all-targets --features legacy-v01 (127 tests, 9 for v0.1) - cargo clippy/test --no-default-features --features decompression,legacy-v01 (module builds standalone) - make -C tests fuzzer && ./tests/fuzzer -i1 --no-big-tests, also with ZSTD_LEGACY_SUPPORT=1 (mixed Rust v0.1 + C v0.2-0.7 link) - make -C tests test-rust-lib-smoke && make -C tests test-legacy - make -C programs zstd (default and ZSTD_LEGACY_SUPPORT=1); nm shows the nine ZSTDv01_* symbols provided by Rust at level 1 - make -C lib libzstd.a ZSTD_LEGACY_SUPPORT=0 (no legacy symbols) and meson -Dlegacy_level=1 shared library exporting all nine --- lib/legacy/zstd_v01.c | 2112 +------------------------------ rust/README.md | 11 +- rust/src/legacy/mod.rs | 2 + rust/src/legacy/zstd_v01.rs | 2354 +++++++++++++++++++++++++++++++++++ 4 files changed, 2367 insertions(+), 2112 deletions(-) create mode 100644 rust/src/legacy/zstd_v01.rs diff --git a/lib/legacy/zstd_v01.c b/lib/legacy/zstd_v01.c index ad3c9330e..17feb29fa 100644 --- a/lib/legacy/zstd_v01.c +++ b/lib/legacy/zstd_v01.c @@ -17,2111 +17,7 @@ #include "../common/compiler.h" #include "../common/error_private.h" - -/****************************************** -* Static allocation -******************************************/ -/* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */ -#define FSE_DTABLE_SIZE_U32(maxTableLog) (1 + (1<2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) -* Increasing memory usage improves compression ratio -* Reduced memory usage can improve speed, due to cache effect -* Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */ -#define FSE_MAX_MEMORY_USAGE 14 -#define FSE_DEFAULT_MEMORY_USAGE 13 - -/* FSE_MAX_SYMBOL_VALUE : -* Maximum symbol value authorized. -* Required for proper stack allocation */ -#define FSE_MAX_SYMBOL_VALUE 255 - - -/**************************************************************** -* template functions type & suffix -****************************************************************/ -#define FSE_FUNCTION_TYPE BYTE -#define FSE_FUNCTION_EXTENSION - - -/**************************************************************** -* Byte symbol type -****************************************************************/ -typedef struct -{ - unsigned short newState; - unsigned char symbol; - unsigned char nbBits; -} FSE_decode_t; /* size == U32 */ - - - -/**************************************************************** -* Compiler specifics -****************************************************************/ -#ifdef _MSC_VER /* Visual Studio */ -# define FORCE_INLINE static __forceinline -# include /* For Visual 2005 */ -# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ -# pragma warning(disable : 4214) /* disable: C4214: non-int bitfields */ -#else -# define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__) -# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ -# ifdef __GNUC__ -# define FORCE_INLINE static inline __attribute__((always_inline)) -# else -# define FORCE_INLINE static inline -# endif -# else -# define FORCE_INLINE static -# endif /* __STDC_VERSION__ */ -#endif - - -/**************************************************************** -* Includes -****************************************************************/ -#include /* malloc, free, qsort */ -#include /* memcpy, memset */ -#include /* printf (debug) */ - - -#ifndef MEM_ACCESS_MODULE -#define MEM_ACCESS_MODULE -/**************************************************************** -* Basic Types -*****************************************************************/ -#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ -# include -typedef uint8_t BYTE; -typedef uint16_t U16; -typedef int16_t S16; -typedef uint32_t U32; -typedef int32_t S32; -typedef uint64_t U64; -typedef int64_t S64; -#else -typedef unsigned char BYTE; -typedef unsigned short U16; -typedef signed short S16; -typedef unsigned int U32; -typedef signed int S32; -typedef unsigned long long U64; -typedef signed long long S64; -#endif - -#endif /* MEM_ACCESS_MODULE */ - -/**************************************************************** -* Memory I/O -*****************************************************************/ - -static unsigned FSE_32bits(void) -{ - return sizeof(void*)==4; -} - -static unsigned FSE_isLittleEndian(void) -{ - const union { U32 i; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */ - return one.c[0]; -} - -static U16 FSE_read16(const void* memPtr) -{ - U16 val; memcpy(&val, memPtr, sizeof(val)); return val; -} - -static U32 FSE_read32(const void* memPtr) -{ - U32 val; memcpy(&val, memPtr, sizeof(val)); return val; -} - -static U64 FSE_read64(const void* memPtr) -{ - U64 val; memcpy(&val, memPtr, sizeof(val)); return val; -} - -static U16 FSE_readLE16(const void* memPtr) -{ - if (FSE_isLittleEndian()) - return FSE_read16(memPtr); - else - { - const BYTE* p = (const BYTE*)memPtr; - return (U16)(p[0] + (p[1]<<8)); - } -} - -static U32 FSE_readLE32(const void* memPtr) -{ - if (FSE_isLittleEndian()) - return FSE_read32(memPtr); - else - { - const BYTE* p = (const BYTE*)memPtr; - return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24)); - } -} - - -static U64 FSE_readLE64(const void* memPtr) -{ - if (FSE_isLittleEndian()) - return FSE_read64(memPtr); - else - { - const BYTE* p = (const BYTE*)memPtr; - return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24) - + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56)); - } -} - -static size_t FSE_readLEST(const void* memPtr) -{ - if (FSE_32bits()) - return (size_t)FSE_readLE32(memPtr); - else - return (size_t)FSE_readLE64(memPtr); -} - - - -/**************************************************************** -* Constants -*****************************************************************/ -#define FSE_MAX_TABLELOG (FSE_MAX_MEMORY_USAGE-2) -#define FSE_MAX_TABLESIZE (1U< FSE_TABLELOG_ABSOLUTE_MAX -#error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported" -#endif - - -/**************************************************************** -* Error Management -****************************************************************/ -#define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */ - - -/**************************************************************** -* Complex types -****************************************************************/ -typedef struct -{ - int deltaFindState; - U32 deltaNbBits; -} FSE_symbolCompressionTransform; /* total 8 bytes */ - -typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)]; - -/**************************************************************** -* Internal functions -****************************************************************/ -FORCE_INLINE unsigned FSE_highbit32 (U32 val) -{ -# if defined(_MSC_VER) /* Visual */ - unsigned long r; - return _BitScanReverse(&r, val) ? (unsigned)r : 0; -# elif defined(__GNUC__) && (GCC_VERSION >= 304) /* GCC Intrinsic */ - return __builtin_clz (val) ^ 31; -# else /* Software version */ - static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 }; - U32 v = val; - unsigned r; - v |= v >> 1; - v |= v >> 2; - v |= v >> 4; - v |= v >> 8; - v |= v >> 16; - r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27]; - return r; -# endif -} - - -/**************************************************************** -* Templates -****************************************************************/ -/* - designed to be included - for type-specific functions (template emulation in C) - Objective is to write these functions only once, for improved maintenance -*/ - -/* safety checks */ -#ifndef FSE_FUNCTION_EXTENSION -# error "FSE_FUNCTION_EXTENSION must be defined" -#endif -#ifndef FSE_FUNCTION_TYPE -# error "FSE_FUNCTION_TYPE must be defined" -#endif - -/* Function names */ -#define FSE_CAT(X,Y) X##Y -#define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y) -#define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y) - - - -static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; } - -#define FSE_DECODE_TYPE FSE_decode_t - - -typedef struct { - U16 tableLog; - U16 fastMode; -} FSE_DTableHeader; /* sizeof U32 */ - -static size_t FSE_buildDTable -(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog) -{ - void* ptr = dt; - FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr; - FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)(ptr) + 1; /* because dt is unsigned, 32-bits aligned on 32-bits */ - const U32 tableSize = 1 << tableLog; - const U32 tableMask = tableSize-1; - const U32 step = FSE_tableStep(tableSize); - U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1]; - U32 position = 0; - U32 highThreshold = tableSize-1; - const S16 largeLimit= (S16)(1 << (tableLog-1)); - U32 noLarge = 1; - U32 s; - - /* Sanity Checks */ - if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return (size_t)-FSE_ERROR_maxSymbolValue_tooLarge; - if (tableLog > FSE_MAX_TABLELOG) return (size_t)-FSE_ERROR_tableLog_tooLarge; - - /* Init, lay down lowprob symbols */ - DTableH[0].tableLog = (U16)tableLog; - for (s=0; s<=maxSymbolValue; s++) - { - if (normalizedCounter[s]==-1) - { - tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s; - symbolNext[s] = 1; - } - else - { - if (normalizedCounter[s] >= largeLimit) noLarge=0; - symbolNext[s] = normalizedCounter[s]; - } - } - - /* Spread symbols */ - for (s=0; s<=maxSymbolValue; s++) - { - int i; - for (i=0; i highThreshold) position = (position + step) & tableMask; /* lowprob area */ - } - } - - if (position!=0) return (size_t)-FSE_ERROR_GENERIC; /* position must reach all cells once, otherwise normalizedCounter is incorrect */ - - /* Build Decoding table */ - { - U32 i; - for (i=0; ifastMode = (U16)noLarge; - return 0; -} - - -/****************************************** -* FSE byte symbol -******************************************/ -#ifndef FSE_COMMONDEFS_ONLY - -static unsigned FSE_isError(size_t code) { return (code > (size_t)(-FSE_ERROR_maxCode)); } - -static short FSE_abs(short a) -{ - return a<0? -a : a; -} - - -/**************************************************************** -* Header bitstream management -****************************************************************/ -static size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr, - const void* headerBuffer, size_t hbSize) -{ - const BYTE* const istart = (const BYTE*) headerBuffer; - const BYTE* const iend = istart + hbSize; - const BYTE* ip = istart; - int nbBits; - int remaining; - int threshold; - U32 bitStream; - int bitCount; - unsigned charnum = 0; - int previous0 = 0; - - if (hbSize < 4) return (size_t)-FSE_ERROR_srcSize_wrong; - bitStream = FSE_readLE32(ip); - nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG; /* extract tableLog */ - if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return (size_t)-FSE_ERROR_tableLog_tooLarge; - bitStream >>= 4; - bitCount = 4; - *tableLogPtr = nbBits; - remaining = (1<1) && (charnum<=*maxSVPtr)) - { - if (previous0) - { - unsigned n0 = charnum; - while ((bitStream & 0xFFFF) == 0xFFFF) - { - n0+=24; - if (ip < iend-5) - { - ip+=2; - bitStream = FSE_readLE32(ip) >> bitCount; - } - else - { - bitStream >>= 16; - bitCount+=16; - } - } - while ((bitStream & 3) == 3) - { - n0+=3; - bitStream>>=2; - bitCount+=2; - } - n0 += bitStream & 3; - bitCount += 2; - if (n0 > *maxSVPtr) return (size_t)-FSE_ERROR_maxSymbolValue_tooSmall; - while (charnum < n0) normalizedCounter[charnum++] = 0; - if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) - { - ip += bitCount>>3; - bitCount &= 7; - bitStream = FSE_readLE32(ip) >> bitCount; - } - else - bitStream >>= 2; - } - { - const short max = (short)((2*threshold-1)-remaining); - short count; - - if ((bitStream & (threshold-1)) < (U32)max) - { - count = (short)(bitStream & (threshold-1)); - bitCount += nbBits-1; - } - else - { - count = (short)(bitStream & (2*threshold-1)); - if (count >= threshold) count -= max; - bitCount += nbBits; - } - - count--; /* extra accuracy */ - remaining -= FSE_abs(count); - normalizedCounter[charnum++] = count; - previous0 = !count; - while (remaining < threshold) - { - nbBits--; - threshold >>= 1; - } - - { - if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) - { - ip += bitCount>>3; - bitCount &= 7; - } - else - { - bitCount -= (int)(8 * (iend - 4 - ip)); - ip = iend - 4; - } - bitStream = FSE_readLE32(ip) >> (bitCount & 31); - } - } - } - if (remaining != 1) return (size_t)-FSE_ERROR_GENERIC; - *maxSVPtr = charnum-1; - - ip += (bitCount+7)>>3; - if ((size_t)(ip-istart) > hbSize) return (size_t)-FSE_ERROR_srcSize_wrong; - return ip-istart; -} - - -/********************************************************* -* Decompression (Byte symbols) -*********************************************************/ -static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue) -{ - void* ptr = dt; - FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr; - FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1; /* because dt is unsigned */ - - DTableH->tableLog = 0; - DTableH->fastMode = 0; - - cell->newState = 0; - cell->symbol = symbolValue; - cell->nbBits = 0; - - return 0; -} - - -static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits) -{ - void* ptr = dt; - FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr; - FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1; /* because dt is unsigned */ - const unsigned tableSize = 1 << nbBits; - const unsigned tableMask = tableSize - 1; - const unsigned maxSymbolValue = tableMask; - unsigned s; - - /* Sanity checks */ - if (nbBits < 1) return (size_t)-FSE_ERROR_GENERIC; /* min size */ - - /* Build Decoding Table */ - DTableH->tableLog = (U16)nbBits; - DTableH->fastMode = 1; - for (s=0; s<=maxSymbolValue; s++) - { - dinfo[s].newState = 0; - dinfo[s].symbol = (BYTE)s; - dinfo[s].nbBits = (BYTE)nbBits; - } - - return 0; -} - - -/* FSE_initDStream - * Initialize a FSE_DStream_t. - * srcBuffer must point at the beginning of an FSE block. - * The function result is the size of the FSE_block (== srcSize). - * If srcSize is too small, the function will return an errorCode; - */ -static size_t FSE_initDStream(FSE_DStream_t* bitD, const void* srcBuffer, size_t srcSize) -{ - if (srcSize < 1) return (size_t)-FSE_ERROR_srcSize_wrong; - - if (srcSize >= sizeof(size_t)) - { - U32 contain32; - bitD->start = (const char*)srcBuffer; - bitD->ptr = (const char*)srcBuffer + srcSize - sizeof(size_t); - bitD->bitContainer = FSE_readLEST(bitD->ptr); - contain32 = ((const BYTE*)srcBuffer)[srcSize-1]; - if (contain32 == 0) return (size_t)-FSE_ERROR_GENERIC; /* stop bit not present */ - bitD->bitsConsumed = 8 - FSE_highbit32(contain32); - } - else - { - U32 contain32; - bitD->start = (const char*)srcBuffer; - bitD->ptr = bitD->start; - bitD->bitContainer = *(const BYTE*)(bitD->start); - switch(srcSize) - { - case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16); - /* fallthrough */ - case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24); - /* fallthrough */ - case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32); - /* fallthrough */ - case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24; - /* fallthrough */ - case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16; - /* fallthrough */ - case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) << 8; - /* fallthrough */ - default:; - } - contain32 = ((const BYTE*)srcBuffer)[srcSize-1]; - if (contain32 == 0) return (size_t)-FSE_ERROR_GENERIC; /* stop bit not present */ - bitD->bitsConsumed = 8 - FSE_highbit32(contain32); - bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8; - } - - return srcSize; -} - - -/*!FSE_lookBits - * Provides next n bits from the bitContainer. - * bitContainer is not modified (bits are still present for next read/look) - * On 32-bits, maxNbBits==25 - * On 64-bits, maxNbBits==57 - * return : value extracted. - */ -static size_t FSE_lookBits(FSE_DStream_t* bitD, U32 nbBits) -{ - const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1; - return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask); -} - -static size_t FSE_lookBitsFast(FSE_DStream_t* bitD, U32 nbBits) /* only if nbBits >= 1 !! */ -{ - const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1; - return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask); -} - -static void FSE_skipBits(FSE_DStream_t* bitD, U32 nbBits) -{ - bitD->bitsConsumed += nbBits; -} - - -/*!FSE_readBits - * Read next n bits from the bitContainer. - * On 32-bits, don't read more than maxNbBits==25 - * On 64-bits, don't read more than maxNbBits==57 - * Use the fast variant *only* if n >= 1. - * return : value extracted. - */ -static size_t FSE_readBits(FSE_DStream_t* bitD, U32 nbBits) -{ - size_t value = FSE_lookBits(bitD, nbBits); - FSE_skipBits(bitD, nbBits); - return value; -} - -static size_t FSE_readBitsFast(FSE_DStream_t* bitD, U32 nbBits) /* only if nbBits >= 1 !! */ -{ - size_t value = FSE_lookBitsFast(bitD, nbBits); - FSE_skipBits(bitD, nbBits); - return value; -} - -static unsigned FSE_reloadDStream(FSE_DStream_t* bitD) -{ - if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8)) /* should never happen */ - return FSE_DStream_tooFar; - - if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer)) - { - bitD->ptr -= bitD->bitsConsumed >> 3; - bitD->bitsConsumed &= 7; - bitD->bitContainer = FSE_readLEST(bitD->ptr); - return FSE_DStream_unfinished; - } - if (bitD->ptr == bitD->start) - { - if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return FSE_DStream_endOfBuffer; - return FSE_DStream_completed; - } - { - U32 nbBytes = bitD->bitsConsumed >> 3; - U32 result = FSE_DStream_unfinished; - if (bitD->ptr - nbBytes < bitD->start) - { - nbBytes = (U32)(bitD->ptr - bitD->start); /* ptr > start */ - result = FSE_DStream_endOfBuffer; - } - bitD->ptr -= nbBytes; - bitD->bitsConsumed -= nbBytes*8; - bitD->bitContainer = FSE_readLEST(bitD->ptr); /* reminder : srcSize > sizeof(bitD) */ - return result; - } -} - - -static void FSE_initDState(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD, const FSE_DTable* dt) -{ - const void* ptr = dt; - const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr; - DStatePtr->state = FSE_readBits(bitD, DTableH->tableLog); - FSE_reloadDStream(bitD); - DStatePtr->table = dt + 1; -} - -static BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD) -{ - const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state]; - const U32 nbBits = DInfo.nbBits; - BYTE symbol = DInfo.symbol; - size_t lowBits = FSE_readBits(bitD, nbBits); - - DStatePtr->state = DInfo.newState + lowBits; - return symbol; -} - -static BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD) -{ - const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state]; - const U32 nbBits = DInfo.nbBits; - BYTE symbol = DInfo.symbol; - size_t lowBits = FSE_readBitsFast(bitD, nbBits); - - DStatePtr->state = DInfo.newState + lowBits; - return symbol; -} - -/* FSE_endOfDStream - Tells if bitD has reached end of bitStream or not */ - -static unsigned FSE_endOfDStream(const FSE_DStream_t* bitD) -{ - return ((bitD->ptr == bitD->start) && (bitD->bitsConsumed == sizeof(bitD->bitContainer)*8)); -} - -static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr) -{ - return DStatePtr->state == 0; -} - - -FORCE_INLINE size_t FSE_decompress_usingDTable_generic( - void* dst, size_t maxDstSize, - const void* cSrc, size_t cSrcSize, - const FSE_DTable* dt, const unsigned fast) -{ - BYTE* const ostart = (BYTE*) dst; - BYTE* op = ostart; - BYTE* const omax = op + maxDstSize; - BYTE* const olimit = omax-3; - - FSE_DStream_t bitD; - FSE_DState_t state1; - FSE_DState_t state2; - size_t errorCode; - - /* Init */ - errorCode = FSE_initDStream(&bitD, cSrc, cSrcSize); /* replaced last arg by maxCompressed Size */ - if (FSE_isError(errorCode)) return errorCode; - - FSE_initDState(&state1, &bitD, dt); - FSE_initDState(&state2, &bitD, dt); - -#define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD) - - /* 4 symbols per loop */ - for ( ; (FSE_reloadDStream(&bitD)==FSE_DStream_unfinished) && (op sizeof(bitD.bitContainer)*8) /* This test must be static */ - FSE_reloadDStream(&bitD); - - op[1] = FSE_GETSYMBOL(&state2); - - if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8) /* This test must be static */ - { if (FSE_reloadDStream(&bitD) > FSE_DStream_unfinished) { op+=2; break; } } - - op[2] = FSE_GETSYMBOL(&state1); - - if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8) /* This test must be static */ - FSE_reloadDStream(&bitD); - - op[3] = FSE_GETSYMBOL(&state2); - } - - /* tail */ - /* note : FSE_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly FSE_DStream_completed */ - while (1) - { - if ( (FSE_reloadDStream(&bitD)>FSE_DStream_completed) || (op==omax) || (FSE_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) ) - break; - - *op++ = FSE_GETSYMBOL(&state1); - - if ( (FSE_reloadDStream(&bitD)>FSE_DStream_completed) || (op==omax) || (FSE_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) ) - break; - - *op++ = FSE_GETSYMBOL(&state2); - } - - /* end ? */ - if (FSE_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2)) - return op-ostart; - - if (op==omax) return (size_t)-FSE_ERROR_dstSize_tooSmall; /* dst buffer is full, but cSrc unfinished */ - - return (size_t)-FSE_ERROR_corruptionDetected; -} - - -static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize, - const void* cSrc, size_t cSrcSize, - const FSE_DTable* dt) -{ - FSE_DTableHeader DTableH; - memcpy(&DTableH, dt, sizeof(DTableH)); /* memcpy() into local variable, to avoid strict aliasing warning */ - - /* select fast mode (static) */ - if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1); - return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0); -} - - -static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize) -{ - const BYTE* const istart = (const BYTE*)cSrc; - const BYTE* ip = istart; - short counting[FSE_MAX_SYMBOL_VALUE+1]; - DTable_max_t dt; /* Static analyzer seems unable to understand this table will be properly initialized later */ - unsigned tableLog; - unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE; - size_t errorCode; - - if (cSrcSize<2) return (size_t)-FSE_ERROR_srcSize_wrong; /* too small input size */ - - /* normal FSE decoding mode */ - errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize); - if (FSE_isError(errorCode)) return errorCode; - if (errorCode >= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong; /* too small input size */ - ip += errorCode; - cSrcSize -= errorCode; - - errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog); - if (FSE_isError(errorCode)) return errorCode; - - /* always return, even if it is an error code */ - return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt); -} - - - -/* ******************************************************* -* Huff0 : Huffman block compression -*********************************************************/ -#define HUF_MAX_SYMBOL_VALUE 255 -#define HUF_DEFAULT_TABLELOG 12 /* used by default, when not specified */ -#define HUF_MAX_TABLELOG 12 /* max possible tableLog; for allocation purpose; can be modified */ -#define HUF_ABSOLUTEMAX_TABLELOG 16 /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */ -#if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG) -# error "HUF_MAX_TABLELOG is too large !" -#endif - -typedef struct HUF_CElt_s { - U16 val; - BYTE nbBits; -} HUF_CElt ; - -typedef struct nodeElt_s { - U32 count; - U16 parent; - BYTE byte; - BYTE nbBits; -} nodeElt; - - -/* ******************************************************* -* Huff0 : Huffman block decompression -*********************************************************/ -typedef struct { - BYTE byte; - BYTE nbBits; -} HUF_DElt; - -static size_t HUF_readDTable (U16* DTable, const void* src, size_t srcSize) -{ - BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1]; - U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1]; /* large enough for values from 0 to 16 */ - U32 weightTotal; - U32 maxBits; - const BYTE* ip = (const BYTE*) src; - size_t iSize; - size_t oSize; - U32 n; - U32 nextRankStart; - void* ptr = DTable+1; - HUF_DElt* const dt = (HUF_DElt*)ptr; - - if (!srcSize) return (size_t)-FSE_ERROR_srcSize_wrong; - iSize = ip[0]; - - FSE_STATIC_ASSERT(sizeof(HUF_DElt) == sizeof(U16)); /* if compilation fails here, assertion is false */ - //memset(huffWeight, 0, sizeof(huffWeight)); /* should not be necessary, but some analyzer complain ... */ - if (iSize >= 128) /* special header */ - { - if (iSize >= (242)) /* RLE */ - { - static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 }; - oSize = l[iSize-242]; - memset(huffWeight, 1, sizeof(huffWeight)); - iSize = 0; - } - else /* Incompressible */ - { - oSize = iSize - 127; - iSize = ((oSize+1)/2); - if (iSize+1 > srcSize) return (size_t)-FSE_ERROR_srcSize_wrong; - ip += 1; - for (n=0; n> 4; - huffWeight[n+1] = ip[n/2] & 15; - } - } - } - else /* header compressed with FSE (normal case) */ - { - if (iSize+1 > srcSize) return (size_t)-FSE_ERROR_srcSize_wrong; - oSize = FSE_decompress(huffWeight, HUF_MAX_SYMBOL_VALUE, ip+1, iSize); /* max 255 values decoded, last one is implied */ - if (FSE_isError(oSize)) return oSize; - } - - /* collect weight stats */ - memset(rankVal, 0, sizeof(rankVal)); - weightTotal = 0; - for (n=0; n= HUF_ABSOLUTEMAX_TABLELOG) return (size_t)-FSE_ERROR_corruptionDetected; - rankVal[huffWeight[n]]++; - weightTotal += (1 << huffWeight[n]) >> 1; - } - if (weightTotal == 0) return (size_t)-FSE_ERROR_corruptionDetected; - - /* get last non-null symbol weight (implied, total must be 2^n) */ - maxBits = FSE_highbit32(weightTotal) + 1; - if (maxBits > DTable[0]) return (size_t)-FSE_ERROR_tableLog_tooLarge; /* DTable is too small */ - DTable[0] = (U16)maxBits; - { - U32 total = 1 << maxBits; - U32 rest = total - weightTotal; - U32 verif = 1 << FSE_highbit32(rest); - U32 lastWeight = FSE_highbit32(rest) + 1; - if (verif != rest) return (size_t)-FSE_ERROR_corruptionDetected; /* last value must be a clean power of 2 */ - huffWeight[oSize] = (BYTE)lastWeight; - rankVal[lastWeight]++; - } - - /* check tree construction validity */ - if ((rankVal[1] < 2) || (rankVal[1] & 1)) return (size_t)-FSE_ERROR_corruptionDetected; /* by construction : at least 2 elts of rank 1, must be even */ - - /* Prepare ranks */ - nextRankStart = 0; - for (n=1; n<=maxBits; n++) - { - U32 current = nextRankStart; - nextRankStart += (rankVal[n] << (n-1)); - rankVal[n] = current; - } - - /* fill DTable */ - for (n=0; n<=oSize; n++) - { - const U32 w = huffWeight[n]; - const U32 length = (1 << w) >> 1; - U32 i; - HUF_DElt D; - D.byte = (BYTE)n; D.nbBits = (BYTE)(maxBits + 1 - w); - for (i = rankVal[w]; i < rankVal[w] + length; i++) - dt[i] = D; - rankVal[w] += length; - } - - return iSize+1; -} - - -static BYTE HUF_decodeSymbol(FSE_DStream_t* Dstream, const HUF_DElt* dt, const U32 dtLog) -{ - const size_t val = FSE_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */ - const BYTE c = dt[val].byte; - FSE_skipBits(Dstream, dt[val].nbBits); - return c; -} - -static size_t HUF_decompress_usingDTable( /* -3% slower when non static */ - void* dst, size_t maxDstSize, - const void* cSrc, size_t cSrcSize, - const U16* DTable) -{ - if (cSrcSize < 6) return (size_t)-FSE_ERROR_srcSize_wrong; - { - BYTE* const ostart = (BYTE*) dst; - BYTE* op = ostart; - BYTE* const omax = op + maxDstSize; - BYTE* const olimit = maxDstSize < 15 ? op : omax-15; - - const void* ptr = DTable; - const HUF_DElt* const dt = (const HUF_DElt*)(ptr)+1; - const U32 dtLog = DTable[0]; - size_t errorCode; - U32 reloadStatus; - - /* Init */ - - const U16* jumpTable = (const U16*)cSrc; - const size_t length1 = FSE_readLE16(jumpTable); - const size_t length2 = FSE_readLE16(jumpTable+1); - const size_t length3 = FSE_readLE16(jumpTable+2); - const size_t length4 = cSrcSize - 6 - length1 - length2 - length3; /* check coherency !! */ - const char* const start1 = (const char*)(cSrc) + 6; - const char* const start2 = start1 + length1; - const char* const start3 = start2 + length2; - const char* const start4 = start3 + length3; - FSE_DStream_t bitD1, bitD2, bitD3, bitD4; - - if (length1+length2+length3+6 >= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong; - - errorCode = FSE_initDStream(&bitD1, start1, length1); - if (FSE_isError(errorCode)) return errorCode; - errorCode = FSE_initDStream(&bitD2, start2, length2); - if (FSE_isError(errorCode)) return errorCode; - errorCode = FSE_initDStream(&bitD3, start3, length3); - if (FSE_isError(errorCode)) return errorCode; - errorCode = FSE_initDStream(&bitD4, start4, length4); - if (FSE_isError(errorCode)) return errorCode; - - reloadStatus=FSE_reloadDStream(&bitD2); - - /* 16 symbols per loop */ - for ( ; (reloadStatus12)) FSE_reloadDStream(&Dstream) - - #define HUF_DECODE_SYMBOL_2(n, Dstream) \ - op[n] = HUF_decodeSymbol(&Dstream, dt, dtLog); \ - if (FSE_32bits()) FSE_reloadDStream(&Dstream) - - HUF_DECODE_SYMBOL_1( 0, bitD1); - HUF_DECODE_SYMBOL_1( 1, bitD2); - HUF_DECODE_SYMBOL_1( 2, bitD3); - HUF_DECODE_SYMBOL_1( 3, bitD4); - HUF_DECODE_SYMBOL_2( 4, bitD1); - HUF_DECODE_SYMBOL_2( 5, bitD2); - HUF_DECODE_SYMBOL_2( 6, bitD3); - HUF_DECODE_SYMBOL_2( 7, bitD4); - HUF_DECODE_SYMBOL_1( 8, bitD1); - HUF_DECODE_SYMBOL_1( 9, bitD2); - HUF_DECODE_SYMBOL_1(10, bitD3); - HUF_DECODE_SYMBOL_1(11, bitD4); - HUF_DECODE_SYMBOL_0(12, bitD1); - HUF_DECODE_SYMBOL_0(13, bitD2); - HUF_DECODE_SYMBOL_0(14, bitD3); - HUF_DECODE_SYMBOL_0(15, bitD4); - } - - if (reloadStatus!=FSE_DStream_completed) /* not complete : some bitStream might be FSE_DStream_unfinished */ - return (size_t)-FSE_ERROR_corruptionDetected; - - /* tail */ - { - /* bitTail = bitD1; */ /* *much* slower : -20% !??! */ - FSE_DStream_t bitTail; - bitTail.ptr = bitD1.ptr; - bitTail.bitsConsumed = bitD1.bitsConsumed; - bitTail.bitContainer = bitD1.bitContainer; /* required in case of FSE_DStream_endOfBuffer */ - bitTail.start = start1; - for ( ; (FSE_reloadDStream(&bitTail) < FSE_DStream_completed) && (op= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong; - ip += errorCode; - cSrcSize -= errorCode; - - return HUF_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, DTable); -} - - -#endif /* FSE_COMMONDEFS_ONLY */ - -/* - zstd - standard compression library - Copyright (C) 2014-2015, Yann Collet. - - BSD 2-Clause License (https://opensource.org/licenses/bsd-license.php) - - Redistribution and use in source and binary forms, with or without - modification, are permitted provided that the following conditions are - met: - * Redistributions of source code must retain the above copyright - notice, this list of conditions and the following disclaimer. - * Redistributions in binary form must reproduce the above - copyright notice, this list of conditions and the following disclaimer - in the documentation and/or other materials provided with the - distribution. - THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR - A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT - OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT - LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE - OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - - You can contact the author at : - - zstd source repository : https://github.com/Cyan4973/zstd - - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c -*/ - -/**************************************************************** -* Tuning parameters -*****************************************************************/ -/* MEMORY_USAGE : -* Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) -* Increasing memory usage improves compression ratio -* Reduced memory usage can improve speed, due to cache effect */ -#define ZSTD_MEMORY_USAGE 17 - - -/************************************** - CPU Feature Detection -**************************************/ -/* - * Automated efficient unaligned memory access detection - * Based on known hardware architectures - * This list will be updated thanks to feedbacks - */ -#if defined(CPU_HAS_EFFICIENT_UNALIGNED_MEMORY_ACCESS) \ - || defined(__ARM_FEATURE_UNALIGNED) \ - || defined(__i386__) || defined(__x86_64__) \ - || defined(_M_IX86) || defined(_M_X64) \ - || defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_8__) \ - || (defined(_M_ARM) && (_M_ARM >= 7)) -# define ZSTD_UNALIGNED_ACCESS 1 -#else -# define ZSTD_UNALIGNED_ACCESS 0 -#endif - - -/******************************************************** -* Includes -*********************************************************/ -#include /* calloc */ -#include /* memcpy, memmove */ -#include /* debug : printf */ - - -/******************************************************** -* Compiler specifics -*********************************************************/ -#ifdef __AVX2__ -# include /* AVX2 intrinsics */ -#endif - -#ifdef _MSC_VER /* Visual Studio */ -# include /* For Visual 2005 */ -# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ -# pragma warning(disable : 4324) /* disable: C4324: padded structure */ -#endif - - -#ifndef MEM_ACCESS_MODULE -#define MEM_ACCESS_MODULE -/******************************************************** -* Basic Types -*********************************************************/ -#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ -# if defined(_AIX) -# include -# else -# include /* intptr_t */ -# endif -typedef uint8_t BYTE; -typedef uint16_t U16; -typedef int16_t S16; -typedef uint32_t U32; -typedef int32_t S32; -typedef uint64_t U64; -#else -typedef unsigned char BYTE; -typedef unsigned short U16; -typedef signed short S16; -typedef unsigned int U32; -typedef signed int S32; -typedef unsigned long long U64; -#endif - -#endif /* MEM_ACCESS_MODULE */ - - -/******************************************************** -* Constants -*********************************************************/ -static const U32 ZSTD_magicNumber = 0xFD2FB51E; /* 3rd version : seqNb header */ - -#define HASH_LOG (ZSTD_MEMORY_USAGE - 2) -#define HASH_TABLESIZE (1 << HASH_LOG) -#define HASH_MASK (HASH_TABLESIZE - 1) - -#define KNUTH 2654435761 - -#define BIT7 128 -#define BIT6 64 -#define BIT5 32 -#define BIT4 16 - -#define KB *(1 <<10) -#define MB *(1 <<20) -#define GB *(1U<<30) - -#define BLOCKSIZE (128 KB) /* define, for static allocation */ - -#define WORKPLACESIZE (BLOCKSIZE*3) -#define MINMATCH 4 -#define MLbits 7 -#define LLbits 6 -#define Offbits 5 -#define MaxML ((1<>3]; -#else - U32 hashTable[HASH_TABLESIZE]; -#endif - BYTE buffer[WORKPLACESIZE]; -} cctxi_t; - - - - -/************************************** -* Error Management -**************************************/ -/* published entry point */ -unsigned ZSTDv01_isError(size_t code) { return ERR_isError(code); } - - -/************************************** -* Tool functions -**************************************/ -#define ZSTD_VERSION_MAJOR 0 /* for breaking interface changes */ -#define ZSTD_VERSION_MINOR 1 /* for new (non-breaking) interface capabilities */ -#define ZSTD_VERSION_RELEASE 3 /* for tweaks, bug-fixes, or development */ -#define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE) - -/************************************************************** -* Decompression code -**************************************************************/ - -static size_t ZSTDv01_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr) -{ - const BYTE* const in = (const BYTE* const)src; - BYTE headerFlags; - U32 cSize; - - if (srcSize < 3) return ERROR(srcSize_wrong); - - headerFlags = *in; - cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16); - - bpPtr->blockType = (blockType_t)(headerFlags >> 6); - bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0; - - if (bpPtr->blockType == bt_end) return 0; - if (bpPtr->blockType == bt_rle) return 1; - return cSize; -} - - -static size_t ZSTD_copyUncompressedBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize) -{ - if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall); - if (srcSize > 0) { - memcpy(dst, src, srcSize); - } - return srcSize; -} - - -static size_t ZSTD_decompressLiterals(void* ctx, - void* dst, size_t maxDstSize, - const void* src, size_t srcSize) -{ - BYTE* op = (BYTE*)dst; - BYTE* const oend = op + maxDstSize; - const BYTE* ip = (const BYTE*)src; - size_t errorCode; - size_t litSize; - - /* check : minimum 2, for litSize, +1, for content */ - if (srcSize <= 3) return ERROR(corruption_detected); - - litSize = ip[1] + (ip[0]<<8); - litSize += ((ip[-3] >> 3) & 7) << 16; /* mmmmh.... */ - op = oend - litSize; - - (void)ctx; - if (litSize > maxDstSize) return ERROR(dstSize_tooSmall); - errorCode = HUF_decompress(op, litSize, ip+2, srcSize-2); - if (FSE_isError(errorCode)) return ERROR(GENERIC); - return litSize; -} - - -static size_t ZSTDv01_decodeLiteralsBlock(void* ctx, - void* dst, size_t maxDstSize, - const BYTE** litStart, size_t* litSize, - const void* src, size_t srcSize) -{ - const BYTE* const istart = (const BYTE* const)src; - const BYTE* ip = istart; - BYTE* const ostart = (BYTE* const)dst; - BYTE* const oend = ostart + maxDstSize; - blockProperties_t litbp; - - size_t litcSize = ZSTDv01_getcBlockSize(src, srcSize, &litbp); - if (ZSTDv01_isError(litcSize)) return litcSize; - if (litcSize > srcSize - ZSTD_blockHeaderSize) return ERROR(srcSize_wrong); - ip += ZSTD_blockHeaderSize; - - switch(litbp.blockType) - { - case bt_raw: - *litStart = ip; - ip += litcSize; - *litSize = litcSize; - break; - case bt_rle: - { - size_t rleSize = litbp.origSize; - if (rleSize>maxDstSize) return ERROR(dstSize_tooSmall); - if (!srcSize) return ERROR(srcSize_wrong); - if (rleSize > 0) { - memset(oend - rleSize, *ip, rleSize); - } - *litStart = oend - rleSize; - *litSize = rleSize; - ip++; - break; - } - case bt_compressed: - { - size_t decodedLitSize = ZSTD_decompressLiterals(ctx, dst, maxDstSize, ip, litcSize); - if (ZSTDv01_isError(decodedLitSize)) return decodedLitSize; - *litStart = oend - decodedLitSize; - *litSize = decodedLitSize; - ip += litcSize; - break; - } - case bt_end: - default: - return ERROR(GENERIC); - } - - return ip-istart; -} - - -static size_t ZSTDv01_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr, - FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb, - const void* src, size_t srcSize) -{ - const BYTE* const istart = (const BYTE* const)src; - const BYTE* ip = istart; - const BYTE* const iend = istart + srcSize; - U32 LLtype, Offtype, MLtype; - U32 LLlog, Offlog, MLlog; - size_t dumpsLength; - - /* check */ - if (srcSize < 5) return ERROR(srcSize_wrong); - - /* SeqHead */ - *nbSeq = ZSTD_readLE16(ip); ip+=2; - LLtype = *ip >> 6; - Offtype = (*ip >> 4) & 3; - MLtype = (*ip >> 2) & 3; - if (*ip & 2) - { - dumpsLength = ip[2]; - dumpsLength += ip[1] << 8; - ip += 3; - } - else - { - dumpsLength = ip[1]; - dumpsLength += (ip[0] & 1) << 8; - ip += 2; - } - *dumpsPtr = ip; - ip += dumpsLength; - *dumpsLengthPtr = dumpsLength; - - /* check */ - if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */ - - /* sequences */ - { - S16 norm[MaxML+1]; /* assumption : MaxML >= MaxLL and MaxOff */ - size_t headerSize; - - /* Build DTables */ - switch(LLtype) - { - case bt_rle : - LLlog = 0; - FSE_buildDTable_rle(DTableLL, *ip++); break; - case bt_raw : - LLlog = LLbits; - FSE_buildDTable_raw(DTableLL, LLbits); break; - default : - { U32 max = MaxLL; - headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip); - if (FSE_isError(headerSize)) return ERROR(GENERIC); - if (LLlog > LLFSELog) return ERROR(corruption_detected); - ip += headerSize; - FSE_buildDTable(DTableLL, norm, max, LLlog); - } } - - switch(Offtype) - { - case bt_rle : - Offlog = 0; - if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */ - FSE_buildDTable_rle(DTableOffb, *ip++); break; - case bt_raw : - Offlog = Offbits; - FSE_buildDTable_raw(DTableOffb, Offbits); break; - default : - { U32 max = MaxOff; - headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip); - if (FSE_isError(headerSize)) return ERROR(GENERIC); - if (Offlog > OffFSELog) return ERROR(corruption_detected); - ip += headerSize; - FSE_buildDTable(DTableOffb, norm, max, Offlog); - } } - - switch(MLtype) - { - case bt_rle : - MLlog = 0; - if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */ - FSE_buildDTable_rle(DTableML, *ip++); break; - case bt_raw : - MLlog = MLbits; - FSE_buildDTable_raw(DTableML, MLbits); break; - default : - { U32 max = MaxML; - headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip); - if (FSE_isError(headerSize)) return ERROR(GENERIC); - if (MLlog > MLFSELog) return ERROR(corruption_detected); - ip += headerSize; - FSE_buildDTable(DTableML, norm, max, MLlog); - } } } - - return ip-istart; -} - - -typedef struct { - size_t litLength; - size_t offset; - size_t matchLength; -} seq_t; - -typedef struct { - FSE_DStream_t DStream; - FSE_DState_t stateLL; - FSE_DState_t stateOffb; - FSE_DState_t stateML; - size_t prevOffset; - const BYTE* dumps; - const BYTE* dumpsEnd; -} seqState_t; - - -static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState) -{ - size_t litLength; - size_t prevOffset; - size_t offset; - size_t matchLength; - const BYTE* dumps = seqState->dumps; - const BYTE* const de = seqState->dumpsEnd; - - /* Literal length */ - litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream)); - prevOffset = litLength ? seq->offset : seqState->prevOffset; - seqState->prevOffset = seq->offset; - if (litLength == MaxLL) - { - const U32 add = dumpsstateOffb), &(seqState->DStream)); - if (ZSTD_32bits()) FSE_reloadDStream(&(seqState->DStream)); - nbBits = offsetCode - 1; - if (offsetCode==0) nbBits = 0; /* cmove */ - offset = ((size_t)1 << (nbBits & ((sizeof(offset)*8)-1))) + FSE_readBits(&(seqState->DStream), nbBits); - if (ZSTD_32bits()) FSE_reloadDStream(&(seqState->DStream)); - if (offsetCode==0) offset = prevOffset; - } - - /* MatchLength */ - matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream)); - if (matchLength == MaxML) - { - const U32 add = dumpslitLength = litLength; - seq->offset = offset; - seq->matchLength = matchLength; - seqState->dumps = dumps; -} - - -static size_t ZSTD_execSequence(BYTE* op, - seq_t sequence, - const BYTE** litPtr, const BYTE* const litLimit, - BYTE* const base, BYTE* const oend) -{ - static const int dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4}; /* added */ - static const int dec64table[] = {8, 8, 8, 7, 8, 9,10,11}; /* subtracted */ - const BYTE* const ostart = op; - BYTE* const oLitEnd = op + sequence.litLength; - const size_t litLength = sequence.litLength; - BYTE* const endMatch = op + litLength + sequence.matchLength; /* risk : address space overflow (32-bits) */ - const BYTE* const litEnd = *litPtr + litLength; - - /* checks */ - size_t const seqLength = sequence.litLength + sequence.matchLength; - - if (seqLength > (size_t)(oend - op)) return ERROR(dstSize_tooSmall); - if (sequence.litLength > (size_t)(litLimit - *litPtr)) return ERROR(corruption_detected); - /* Now we know there are no overflow in literal nor match lengths, can use pointer checks */ - if (sequence.offset > (U32)(oLitEnd - base)) return ERROR(corruption_detected); - - if (endMatch > oend) return ERROR(dstSize_tooSmall); /* overwrite beyond dst buffer */ - if (litEnd > litLimit) return ERROR(corruption_detected); /* overRead beyond lit buffer */ - if (sequence.matchLength > (size_t)(*litPtr-op)) return ERROR(dstSize_tooSmall); /* overwrite literal segment */ - - /* copy Literals */ - ZSTD_memmove(op, *litPtr, sequence.litLength); /* note : v0.1 seems to allow scenarios where output or input are close to end of buffer */ - - op += litLength; - *litPtr = litEnd; /* update for next sequence */ - - /* check : last match must be at a minimum distance of 8 from end of dest buffer */ - if (oend-op < 8) return ERROR(dstSize_tooSmall); - - /* copy Match */ - { - const U32 overlapRisk = (((size_t)(litEnd - endMatch)) < 12); - const BYTE* match = op - sequence.offset; /* possible underflow at op - offset ? */ - size_t qutt = 12; - U64 saved[2]; - - /* check */ - if (match < base) return ERROR(corruption_detected); - if (sequence.offset > (size_t)base) return ERROR(corruption_detected); - - /* save beginning of literal sequence, in case of write overlap */ - if (overlapRisk) - { - if ((endMatch + qutt) > oend) qutt = oend-endMatch; - memcpy(saved, endMatch, qutt); - } - - if (sequence.offset < 8) - { - const int dec64 = dec64table[sequence.offset]; - op[0] = match[0]; - op[1] = match[1]; - op[2] = match[2]; - op[3] = match[3]; - match += dec32table[sequence.offset]; - ZSTD_copy4(op+4, match); - match -= dec64; - } else { ZSTD_copy8(op, match); } - op += 8; match += 8; - - if (endMatch > oend-(16-MINMATCH)) - { - if (op < oend-8) - { - ZSTD_wildcopy(op, match, (oend-8) - op); - match += (oend-8) - op; - op = oend-8; - } - while (opLLTable; - U32* DTableML = dctx->MLTable; - U32* DTableOffb = dctx->OffTable; - BYTE* const base = (BYTE*) (dctx->base); - - /* Build Decoding Tables */ - errorCode = ZSTDv01_decodeSeqHeaders(&nbSeq, &dumps, &dumpsLength, - DTableLL, DTableML, DTableOffb, - ip, iend-ip); - if (ZSTDv01_isError(errorCode)) return errorCode; - ip += errorCode; - - /* Regen sequences */ - { - seq_t sequence; - seqState_t seqState; - - memset(&sequence, 0, sizeof(sequence)); - seqState.dumps = dumps; - seqState.dumpsEnd = dumps + dumpsLength; - seqState.prevOffset = 1; - errorCode = FSE_initDStream(&(seqState.DStream), ip, iend-ip); - if (FSE_isError(errorCode)) return ERROR(corruption_detected); - FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL); - FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb); - FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML); - - for ( ; (FSE_reloadDStream(&(seqState.DStream)) <= FSE_DStream_completed) && (nbSeq>0) ; ) - { - size_t oneSeqSize; - nbSeq--; - ZSTD_decodeSequence(&sequence, &seqState); - oneSeqSize = ZSTD_execSequence(op, sequence, &litPtr, litEnd, base, oend); - if (ZSTDv01_isError(oneSeqSize)) return oneSeqSize; - op += oneSeqSize; - } - - /* check if reached exact end */ - if ( !FSE_endOfDStream(&(seqState.DStream)) ) return ERROR(corruption_detected); /* requested too much : data is corrupted */ - if (nbSeq<0) return ERROR(corruption_detected); /* requested too many sequences : data is corrupted */ - - /* last literal segment */ - { - size_t lastLLSize = litEnd - litPtr; - if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall); - if (lastLLSize > 0) { - if (op != litPtr) memmove(op, litPtr, lastLLSize); - op += lastLLSize; - } - } - } - - return op-ostart; -} - - -static size_t ZSTD_decompressBlock( - void* ctx, - void* dst, size_t maxDstSize, - const void* src, size_t srcSize) -{ - /* blockType == blockCompressed, srcSize is trusted */ - const BYTE* ip = (const BYTE*)src; - const BYTE* litPtr = NULL; - size_t litSize = 0; - size_t errorCode; - - /* Decode literals sub-block */ - errorCode = ZSTDv01_decodeLiteralsBlock(ctx, dst, maxDstSize, &litPtr, &litSize, src, srcSize); - if (ZSTDv01_isError(errorCode)) return errorCode; - ip += errorCode; - srcSize -= errorCode; - - return ZSTD_decompressSequences(ctx, dst, maxDstSize, ip, srcSize, litPtr, litSize); -} - - -size_t ZSTDv01_decompressDCtx(void* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize) -{ - const BYTE* ip = (const BYTE*)src; - const BYTE* iend = ip + srcSize; - BYTE* const ostart = (BYTE* const)dst; - BYTE* op = ostart; - BYTE* const oend = ostart + maxDstSize; - size_t remainingSize = srcSize; - U32 magicNumber; - size_t errorCode=0; - blockProperties_t blockProperties; - - /* Frame Header */ - if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong); - magicNumber = ZSTD_readBE32(src); - if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown); - ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize; - - /* Loop on each block */ - while (1) - { - size_t blockSize = ZSTDv01_getcBlockSize(ip, iend-ip, &blockProperties); - if (ZSTDv01_isError(blockSize)) return blockSize; - - ip += ZSTD_blockHeaderSize; - remainingSize -= ZSTD_blockHeaderSize; - if (blockSize > remainingSize) return ERROR(srcSize_wrong); - - switch(blockProperties.blockType) - { - case bt_compressed: - errorCode = ZSTD_decompressBlock(ctx, op, oend-op, ip, blockSize); - break; - case bt_raw : - errorCode = ZSTD_copyUncompressedBlock(op, oend-op, ip, blockSize); - break; - case bt_rle : - return ERROR(GENERIC); /* not yet supported */ - break; - case bt_end : - /* end of frame */ - if (remainingSize) return ERROR(srcSize_wrong); - break; - default: - return ERROR(GENERIC); - } - if (blockSize == 0) break; /* bt_end */ - - if (ZSTDv01_isError(errorCode)) return errorCode; - op += errorCode; - ip += blockSize; - remainingSize -= blockSize; - } - - return op-ostart; -} - -size_t ZSTDv01_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize) -{ - dctx_t ctx; - ctx.base = dst; - return ZSTDv01_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize); -} - -/* ZSTD_errorFrameSizeInfoLegacy() : - assumes `cSize` and `dBound` are _not_ NULL */ -static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret) -{ - *cSize = ret; - *dBound = ZSTD_CONTENTSIZE_ERROR; -} - -void ZSTDv01_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound) -{ - const BYTE* ip = (const BYTE*)src; - size_t remainingSize = srcSize; - size_t nbBlocks = 0; - U32 magicNumber; - blockProperties_t blockProperties; - - /* Frame Header */ - if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) { - ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong)); - return; - } - magicNumber = ZSTD_readBE32(src); - if (magicNumber != ZSTD_magicNumber) { - ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown)); - return; - } - ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize; - - /* Loop on each block */ - while (1) - { - size_t blockSize = ZSTDv01_getcBlockSize(ip, remainingSize, &blockProperties); - if (ZSTDv01_isError(blockSize)) { - ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, blockSize); - return; - } - - ip += ZSTD_blockHeaderSize; - remainingSize -= ZSTD_blockHeaderSize; - if (blockSize > remainingSize) { - ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong)); - return; - } - - if (blockSize == 0) break; /* bt_end */ - - ip += blockSize; - remainingSize -= blockSize; - nbBlocks++; - } - - *cSize = ip - (const BYTE*)src; - *dBound = nbBlocks * BLOCKSIZE; -} - -/******************************* -* Streaming Decompression API -*******************************/ - -size_t ZSTDv01_resetDCtx(ZSTDv01_Dctx* dctx) -{ - dctx->expected = ZSTD_frameHeaderSize; - dctx->phase = 0; - dctx->previousDstEnd = NULL; - dctx->base = NULL; - return 0; -} - -ZSTDv01_Dctx* ZSTDv01_createDCtx(void) -{ - ZSTDv01_Dctx* dctx = (ZSTDv01_Dctx*)malloc(sizeof(ZSTDv01_Dctx)); - if (dctx==NULL) return NULL; - ZSTDv01_resetDCtx(dctx); - return dctx; -} - -size_t ZSTDv01_freeDCtx(ZSTDv01_Dctx* dctx) -{ - free(dctx); - return 0; -} - -size_t ZSTDv01_nextSrcSizeToDecompress(ZSTDv01_Dctx* dctx) -{ - return ((dctx_t*)dctx)->expected; -} - -size_t ZSTDv01_decompressContinue(ZSTDv01_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize) -{ - dctx_t* ctx = (dctx_t*)dctx; - - /* Sanity check */ - if (srcSize != ctx->expected) return ERROR(srcSize_wrong); - if (dst != ctx->previousDstEnd) /* not contiguous */ - ctx->base = dst; - - /* Decompress : frame header */ - if (ctx->phase == 0) - { - /* Check frame magic header */ - U32 magicNumber = ZSTD_readBE32(src); - if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown); - ctx->phase = 1; - ctx->expected = ZSTD_blockHeaderSize; - return 0; - } - - /* Decompress : block header */ - if (ctx->phase == 1) - { - blockProperties_t bp; - size_t blockSize = ZSTDv01_getcBlockSize(src, ZSTD_blockHeaderSize, &bp); - if (ZSTDv01_isError(blockSize)) return blockSize; - if (bp.blockType == bt_end) - { - ctx->expected = 0; - ctx->phase = 0; - } - else - { - ctx->expected = blockSize; - ctx->bType = bp.blockType; - ctx->phase = 2; - } - - return 0; - } - - /* Decompress : block content */ - { - size_t rSize; - switch(ctx->bType) - { - case bt_compressed: - rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize); - break; - case bt_raw : - rSize = ZSTD_copyUncompressedBlock(dst, maxDstSize, src, srcSize); - break; - case bt_rle : - return ERROR(GENERIC); /* not yet handled */ - break; - case bt_end : /* should never happen (filtered at phase 1) */ - rSize = 0; - break; - default: - return ERROR(GENERIC); - } - ctx->phase = 1; - ctx->expected = ZSTD_blockHeaderSize; - if (ZSTDv01_isError(rSize)) return rSize; - ctx->previousDstEnd = (void*)( ((char*)dst) + rSize); - return rSize; - } - -} +/* Implementation moved to Rust (rust/src/legacy/zstd_v01.rs). + * The frozen v0.1 decoder, including its embedded FSE/Huff0 snapshot and the + * ZSTDv01_Dctx streaming state, now lives entirely in Rust; C code only ever + * holds an opaque ZSTDv01_Dctx pointer. */ diff --git a/rust/README.md b/rust/README.md index 090ec46fd..3dca810ef 100644 --- a/rust/README.md +++ b/rust/README.md @@ -48,8 +48,9 @@ zstd ABI: - Dictionary support - `zstd_ddict` owns, loads, copies, and references decode dictionaries. - Legacy decoding - - `legacy` hosts one frozen module per historical format (v0.1 through - v0.7). No version has been ported yet; all decoders are still C. + - `legacy` hosts one frozen module per historical format; `legacy::zstd_v01` + ports the self-contained v0.1 decoder. Versions v0.2 through v0.7 are + still C. - Block decompression - `zstd_decompress_block` decodes literal and sequence sections, maintains FSE/Huffman repeat state, and executes compressed-block sequences. @@ -64,7 +65,7 @@ zstd ABI: metadata, and streaming I/O. The optimal block matcher, high-level frame compression, dictionary-building, -the legacy v0.1-v0.7 decoders, and the CLI file-I/O backend are still C. They +the legacy v0.2-v0.7 decoders, and the CLI file-I/O backend are still C. They must move before the rewrite is complete. Keeping that boundary explicit prevents a passing hybrid build from being mistaken for the final all-Rust result. @@ -101,7 +102,9 @@ A feature whose version has not been ported yet gates nothing; the original C file still provides that decoder, so mixed C/Rust legacy levels link cleanly. Porting a version means adding `src/legacy/zstd_v0N.rs`, registering it in `src/legacy/mod.rs` behind its feature, and reducing -`lib/legacy/zstd_v0N.c` to a declaration-only shim. +`lib/legacy/zstd_v0N.c` to a declaration-only shim. For v0.1 the streaming +`ZSTDv01_Dctx` state lives entirely in Rust: C code only ever holds an opaque +pointer, so the C-side struct definition is gone. ## Compatibility boundary diff --git a/rust/src/legacy/mod.rs b/rust/src/legacy/mod.rs index df2d785b0..fec4e55dd 100644 --- a/rust/src/legacy/mod.rs +++ b/rust/src/legacy/mod.rs @@ -36,3 +36,5 @@ //! pub mod zstd_v0N; //! ``` +#[cfg(feature = "legacy-v01")] +pub mod zstd_v01; diff --git a/rust/src/legacy/zstd_v01.rs b/rust/src/legacy/zstd_v01.rs new file mode 100644 index 000000000..e48789d59 --- /dev/null +++ b/rust/src/legacy/zstd_v01.rs @@ -0,0 +1,2354 @@ +#![allow(non_snake_case)] + +//! Frozen decoder for the zstd v0.1 format. +//! +//! This is a line-by-line port of `lib/legacy/zstd_v01.c`: the same table +//! layouts, the same arithmetic, and the same error codes. The C file is a +//! self-contained snapshot of the v0.1-era FSE and Huff0 coders, so this +//! module deliberately reimplements them instead of reusing the modern +//! `fse_decompress`/`huf_decompress` modules (see `legacy/mod.rs` for the +//! frozen-decoder policy). The only shared dependency is `crate::errors`, +//! mirroring the C file's `error_private.h` include. +//! +//! The streaming `ZSTDv01_Dctx` state lives entirely in Rust; C callers only +//! ever hold an opaque pointer to it. It is allocated with `libc::malloc` +//! and released with `libc::free`, exactly like the original C context. + +use crate::errors::{ERR_isError, ZstdErrorCode, ERROR}; +use std::os::raw::{c_uint, c_void}; +use std::ptr; + +/* ****************************************** + * Error management (frozen v0.1 FSE codes) + ********************************************/ +/* FSE_LIST_ERRORS in zstd_v01.c; values are returned as `(size_t)-code`. */ +const FSE_ERROR_GENERIC: usize = 1; +const FSE_ERROR_TABLELOG_TOO_LARGE: usize = 2; +const FSE_ERROR_MAX_SYMBOL_VALUE_TOO_LARGE: usize = 3; +const FSE_ERROR_MAX_SYMBOL_VALUE_TOO_SMALL: usize = 4; +const FSE_ERROR_DST_SIZE_TOO_SMALL: usize = 5; +const FSE_ERROR_SRC_SIZE_WRONG: usize = 6; +const FSE_ERROR_CORRUPTION_DETECTED: usize = 7; +const FSE_ERROR_MAX_CODE: usize = 8; + +#[inline] +fn fse_error(code: usize) -> usize { + code.wrapping_neg() +} + +#[inline] +fn fse_is_error(code: usize) -> bool { + code > fse_error(FSE_ERROR_MAX_CODE) +} + +/* ****************************************** + * Tuning parameters (frozen) + ********************************************/ +const FSE_MAX_MEMORY_USAGE: u32 = 14; +const FSE_MAX_SYMBOL_VALUE: u32 = 255; + +const FSE_MAX_TABLELOG: u32 = FSE_MAX_MEMORY_USAGE - 2; +const FSE_MIN_TABLELOG: u32 = 5; +const FSE_TABLELOG_ABSOLUTE_MAX: u32 = 15; + +const HUF_MAX_SYMBOL_VALUE: u32 = 255; +const HUF_MAX_TABLELOG: u32 = 12; +const HUF_ABSOLUTEMAX_TABLELOG: u32 = 16; + +const IS_32BITS: bool = std::mem::size_of::() == 4; +const USIZE_BITS: u32 = usize::BITS; + +/* ****************************************** + * Memory I/O (FSE_read* / ZSTD_read* helpers) + ********************************************/ +#[inline] +unsafe fn fse_read_le16(mem_ptr: *const u8) -> u16 { + u16::from_le_bytes(ptr::read_unaligned(mem_ptr as *const [u8; 2])) +} + +#[inline] +unsafe fn fse_read_le32(mem_ptr: *const u8) -> u32 { + u32::from_le_bytes(ptr::read_unaligned(mem_ptr as *const [u8; 4])) +} + +#[inline] +unsafe fn fse_read_le64(mem_ptr: *const u8) -> u64 { + u64::from_le_bytes(ptr::read_unaligned(mem_ptr as *const [u8; 8])) +} + +#[inline] +unsafe fn fse_read_lest(mem_ptr: *const u8) -> usize { + if IS_32BITS { + fse_read_le32(mem_ptr) as usize + } else { + fse_read_le64(mem_ptr) as usize + } +} + +/// `FSE_highbit32`; the caller guarantees `val != 0`, as in C. +#[inline] +fn fse_highbit32(val: u32) -> u32 { + val.leading_zeros() ^ 31 +} + +/* ****************************************** + * FSE structures + ********************************************/ +#[repr(C)] +#[derive(Clone, Copy)] +struct FseDecode { + new_state: u16, + symbol: u8, + nb_bits: u8, +} + +#[repr(C)] +struct FseDTableHeader { + table_log: u16, + fast_mode: u16, +} + +struct FseDStream { + bit_container: usize, + bits_consumed: u32, + ptr: *const u8, + start: *const u8, +} + +struct FseDState { + state: usize, + table: *const FseDecode, +} + +const FSE_DSTREAM_UNFINISHED: u32 = 0; +const FSE_DSTREAM_END_OF_BUFFER: u32 = 1; +const FSE_DSTREAM_COMPLETED: u32 = 2; +const FSE_DSTREAM_TOO_FAR: u32 = 3; + +#[inline] +fn fse_table_step(table_size: u32) -> u32 { + (table_size >> 1) + (table_size >> 3) + 3 +} + +/* An FSE_DTable is an opaque u32 array: one header word followed by + * `1 << tableLog` FseDecode entries, exactly as in C. */ +unsafe fn fse_build_dtable( + dt: *mut u32, + normalized_counter: *const i16, + max_symbol_value: u32, + table_log: u32, +) -> usize { + let dtable_h = dt as *mut FseDTableHeader; + let table_decode = dt.add(1) as *mut FseDecode; + + /* Sanity checks */ + if max_symbol_value > FSE_MAX_SYMBOL_VALUE { + return fse_error(FSE_ERROR_MAX_SYMBOL_VALUE_TOO_LARGE); + } + if table_log > FSE_MAX_TABLELOG { + return fse_error(FSE_ERROR_TABLELOG_TOO_LARGE); + } + + let table_size: u32 = 1 << table_log; + let table_mask = table_size - 1; + let step = fse_table_step(table_size); + let mut symbol_next = [0u16; (FSE_MAX_SYMBOL_VALUE + 1) as usize]; + let mut position: u32 = 0; + let mut high_threshold = table_size - 1; + let large_limit = (1i32 << (table_log - 1)) as i16; + let mut no_large: u32 = 1; + + /* Init, lay down lowprob symbols */ + (*dtable_h).table_log = table_log as u16; + for s in 0..=max_symbol_value { + let count = *normalized_counter.add(s as usize); + if count == -1 { + (*table_decode.add(high_threshold as usize)).symbol = s as u8; + high_threshold = high_threshold.wrapping_sub(1); + symbol_next[s as usize] = 1; + } else { + if count >= large_limit { + no_large = 0; + } + symbol_next[s as usize] = count as u16; + } + } + + /* Spread symbols */ + for s in 0..=max_symbol_value { + let count = *normalized_counter.add(s as usize); + let mut i = 0i32; + while i < count as i32 { + (*table_decode.add(position as usize)).symbol = s as u8; + position = (position + step) & table_mask; + while position > high_threshold { + position = (position + step) & table_mask; /* lowprob area */ + } + i += 1; + } + } + + if position != 0 { + /* position must reach all cells once, otherwise normalizedCounter is incorrect */ + return fse_error(FSE_ERROR_GENERIC); + } + + /* Build Decoding table */ + for i in 0..table_size as usize { + let symbol = (*table_decode.add(i)).symbol; + let next_state = symbol_next[symbol as usize]; + symbol_next[symbol as usize] = next_state.wrapping_add(1); + let nb_bits = (table_log - fse_highbit32(next_state as u32)) as u8; + (*table_decode.add(i)).nb_bits = nb_bits; + (*table_decode.add(i)).new_state = + (((next_state as u32) << nb_bits).wrapping_sub(table_size)) as u16; + } + + (*dtable_h).fast_mode = no_large as u16; + 0 +} + +/* ****************************************** + * FSE header bitstream (FSE_readNCount) + ********************************************/ +unsafe fn fse_read_ncount( + normalized_counter: *mut i16, + max_sv_ptr: &mut u32, + table_log_ptr: &mut u32, + header_buffer: *const u8, + hb_size: usize, +) -> usize { + let istart = header_buffer; + let iend_addr = (istart as usize).wrapping_add(hb_size); + let mut ip = istart; + let mut charnum: u32 = 0; + let mut previous0 = false; + + if hb_size < 4 { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + let mut bit_stream = fse_read_le32(ip); + let mut nb_bits: i32 = ((bit_stream & 0xF) + FSE_MIN_TABLELOG) as i32; /* extract tableLog */ + if nb_bits > FSE_TABLELOG_ABSOLUTE_MAX as i32 { + return fse_error(FSE_ERROR_TABLELOG_TOO_LARGE); + } + bit_stream >>= 4; + let mut bit_count: i32 = 4; + *table_log_ptr = nb_bits as u32; + let mut remaining: i32 = (1 << nb_bits) + 1; + let mut threshold: i32 = 1 << nb_bits; + nb_bits += 1; + + while remaining > 1 && charnum <= *max_sv_ptr { + if previous0 { + let mut n0 = charnum; + while (bit_stream & 0xFFFF) == 0xFFFF { + n0 += 24; + if (ip as usize) < iend_addr.wrapping_sub(5) { + ip = ip.add(2); + bit_stream = fse_read_le32(ip).wrapping_shr(bit_count as u32); + } else { + bit_stream >>= 16; + bit_count += 16; + } + } + while (bit_stream & 3) == 3 { + n0 += 3; + bit_stream >>= 2; + bit_count += 2; + } + n0 += bit_stream & 3; + bit_count += 2; + if n0 > *max_sv_ptr { + return fse_error(FSE_ERROR_MAX_SYMBOL_VALUE_TOO_SMALL); + } + while charnum < n0 { + *normalized_counter.add(charnum as usize) = 0; + charnum += 1; + } + if (ip as usize) <= iend_addr.wrapping_sub(7) + || (ip as usize).wrapping_add((bit_count >> 3) as usize) + <= iend_addr.wrapping_sub(4) + { + ip = ip.add((bit_count >> 3) as usize); + bit_count &= 7; + bit_stream = fse_read_le32(ip).wrapping_shr(bit_count as u32); + } else { + bit_stream >>= 2; + } + } + { + let max: i16 = ((2 * threshold - 1) - remaining) as i16; + let mut count: i16; + + if (bit_stream & (threshold - 1) as u32) < max as i32 as u32 { + count = (bit_stream & (threshold - 1) as u32) as u16 as i16; + bit_count += nb_bits - 1; + } else { + count = (bit_stream & (2 * threshold - 1) as u32) as u16 as i16; + if count as i32 >= threshold { + count = ((count as i32) - (max as i32)) as i16; + } + bit_count += nb_bits; + } + + count = count.wrapping_sub(1); /* extra accuracy */ + remaining -= (count as i32).abs(); + *normalized_counter.add(charnum as usize) = count; + charnum += 1; + previous0 = count == 0; + while remaining < threshold { + nb_bits -= 1; + threshold >>= 1; + } + + if (ip as usize) <= iend_addr.wrapping_sub(7) + || (ip as usize).wrapping_add((bit_count >> 3) as usize) + <= iend_addr.wrapping_sub(4) + { + ip = ip.add((bit_count >> 3) as usize); + bit_count &= 7; + } else { + bit_count -= + (8 * (iend_addr.wrapping_sub(4) as isize - ip as usize as isize)) as i32; + ip = (iend_addr - 4) as *const u8; + } + bit_stream = fse_read_le32(ip).wrapping_shr((bit_count & 31) as u32); + } + } + if remaining != 1 { + return fse_error(FSE_ERROR_GENERIC); + } + *max_sv_ptr = charnum - 1; + + ip = ip.wrapping_offset(((bit_count + 7) >> 3) as isize); + if (ip as usize).wrapping_sub(istart as usize) > hb_size { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + (ip as usize).wrapping_sub(istart as usize) +} + +/* ****************************************** + * FSE decompression, byte symbols + ********************************************/ +unsafe fn fse_build_dtable_rle(dt: *mut u32, symbol_value: u8) -> usize { + let dtable_h = dt as *mut FseDTableHeader; + let cell = dt.add(1) as *mut FseDecode; + + (*dtable_h).table_log = 0; + (*dtable_h).fast_mode = 0; + + (*cell).new_state = 0; + (*cell).symbol = symbol_value; + (*cell).nb_bits = 0; + + 0 +} + +unsafe fn fse_build_dtable_raw(dt: *mut u32, nb_bits: u32) -> usize { + let dtable_h = dt as *mut FseDTableHeader; + let dinfo = dt.add(1) as *mut FseDecode; + + /* Sanity checks */ + if nb_bits < 1 { + return fse_error(FSE_ERROR_GENERIC); /* min size */ + } + let table_size: u32 = 1 << nb_bits; + let table_mask = table_size - 1; + let max_symbol_value = table_mask; + + (*dtable_h).table_log = nb_bits as u16; + (*dtable_h).fast_mode = 1; + for s in 0..=max_symbol_value { + let cell = dinfo.add(s as usize); + (*cell).new_state = 0; + (*cell).symbol = s as u8; + (*cell).nb_bits = nb_bits as u8; + } + + 0 +} + +unsafe fn fse_init_dstream( + bit_d: &mut FseDStream, + src_buffer: *const u8, + src_size: usize, +) -> usize { + let word = std::mem::size_of::(); + if src_size < 1 { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + + if src_size >= word { + bit_d.start = src_buffer; + bit_d.ptr = src_buffer.add(src_size - word); + bit_d.bit_container = fse_read_lest(bit_d.ptr); + let contain32 = *src_buffer.add(src_size - 1) as u32; + if contain32 == 0 { + return fse_error(FSE_ERROR_GENERIC); /* stop bit not present */ + } + bit_d.bits_consumed = 8 - fse_highbit32(contain32); + } else { + bit_d.start = src_buffer; + bit_d.ptr = bit_d.start; + bit_d.bit_container = *bit_d.start as usize; + /* C switch with fallthrough over srcSize 7..2 */ + if src_size >= 7 { + bit_d.bit_container += (*src_buffer.add(6) as usize) << (USIZE_BITS as usize - 16); + } + if src_size >= 6 { + bit_d.bit_container += (*src_buffer.add(5) as usize) << (USIZE_BITS as usize - 24); + } + if src_size >= 5 { + bit_d.bit_container += (*src_buffer.add(4) as usize) << (USIZE_BITS as usize - 32); + } + if src_size >= 4 { + bit_d.bit_container += (*src_buffer.add(3) as usize) << 24; + } + if src_size >= 3 { + bit_d.bit_container += (*src_buffer.add(2) as usize) << 16; + } + if src_size >= 2 { + bit_d.bit_container += (*src_buffer.add(1) as usize) << 8; + } + let contain32 = *src_buffer.add(src_size - 1) as u32; + if contain32 == 0 { + return fse_error(FSE_ERROR_GENERIC); /* stop bit not present */ + } + bit_d.bits_consumed = 8 - fse_highbit32(contain32); + bit_d.bits_consumed += ((word - src_size) * 8) as u32; + } + + src_size +} + +#[inline] +unsafe fn fse_look_bits(bit_d: &FseDStream, nb_bits: u32) -> usize { + let bit_mask = USIZE_BITS - 1; + ((bit_d.bit_container << (bit_d.bits_consumed & bit_mask)) >> 1) + >> (bit_mask.wrapping_sub(nb_bits) & bit_mask) +} + +#[inline] +unsafe fn fse_look_bits_fast(bit_d: &FseDStream, nb_bits: u32) -> usize { + /* only if nb_bits >= 1 */ + let bit_mask = USIZE_BITS - 1; + (bit_d.bit_container << (bit_d.bits_consumed & bit_mask)) + >> ((bit_mask + 1).wrapping_sub(nb_bits) & bit_mask) +} + +#[inline] +fn fse_skip_bits(bit_d: &mut FseDStream, nb_bits: u32) { + bit_d.bits_consumed = bit_d.bits_consumed.wrapping_add(nb_bits); +} + +#[inline] +unsafe fn fse_read_bits(bit_d: &mut FseDStream, nb_bits: u32) -> usize { + let value = fse_look_bits(bit_d, nb_bits); + fse_skip_bits(bit_d, nb_bits); + value +} + +#[inline] +unsafe fn fse_read_bits_fast(bit_d: &mut FseDStream, nb_bits: u32) -> usize { + /* only if nb_bits >= 1 */ + let value = fse_look_bits_fast(bit_d, nb_bits); + fse_skip_bits(bit_d, nb_bits); + value +} + +unsafe fn fse_reload_dstream(bit_d: &mut FseDStream) -> u32 { + let word = std::mem::size_of::(); + if bit_d.bits_consumed > (word * 8) as u32 { + /* should never happen */ + return FSE_DSTREAM_TOO_FAR; + } + + if (bit_d.ptr as usize) >= (bit_d.start as usize).wrapping_add(word) { + bit_d.ptr = bit_d.ptr.sub((bit_d.bits_consumed >> 3) as usize); + bit_d.bits_consumed &= 7; + bit_d.bit_container = fse_read_lest(bit_d.ptr); + return FSE_DSTREAM_UNFINISHED; + } + if bit_d.ptr == bit_d.start { + if bit_d.bits_consumed < (word * 8) as u32 { + return FSE_DSTREAM_END_OF_BUFFER; + } + return FSE_DSTREAM_COMPLETED; + } + { + let mut nb_bytes = bit_d.bits_consumed >> 3; + let mut result = FSE_DSTREAM_UNFINISHED; + if (bit_d.ptr as usize).wrapping_sub(nb_bytes as usize) < (bit_d.start as usize) { + nb_bytes = ((bit_d.ptr as usize) - (bit_d.start as usize)) as u32; /* ptr > start */ + result = FSE_DSTREAM_END_OF_BUFFER; + } + bit_d.ptr = bit_d.ptr.sub(nb_bytes as usize); + bit_d.bits_consumed -= nb_bytes * 8; + bit_d.bit_container = fse_read_lest(bit_d.ptr); /* reminder : srcSize > sizeof(bitD) */ + result + } +} + +unsafe fn fse_init_dstate(d_state: &mut FseDState, bit_d: &mut FseDStream, dt: *const u32) { + let dtable_h = dt as *const FseDTableHeader; + d_state.state = fse_read_bits(bit_d, (*dtable_h).table_log as u32); + fse_reload_dstream(bit_d); + d_state.table = dt.add(1) as *const FseDecode; +} + +unsafe fn fse_decode_symbol(d_state: &mut FseDState, bit_d: &mut FseDStream) -> u8 { + let d_info = *d_state.table.add(d_state.state); + let low_bits = fse_read_bits(bit_d, d_info.nb_bits as u32); + d_state.state = (d_info.new_state as usize).wrapping_add(low_bits); + d_info.symbol +} + +unsafe fn fse_decode_symbol_fast(d_state: &mut FseDState, bit_d: &mut FseDStream) -> u8 { + let d_info = *d_state.table.add(d_state.state); + let low_bits = fse_read_bits_fast(bit_d, d_info.nb_bits as u32); + d_state.state = (d_info.new_state as usize).wrapping_add(low_bits); + d_info.symbol +} + +#[inline] +fn fse_end_of_dstream(bit_d: &FseDStream) -> bool { + bit_d.ptr == bit_d.start && bit_d.bits_consumed == USIZE_BITS +} + +#[inline] +fn fse_end_of_dstate(d_state: &FseDState) -> bool { + d_state.state == 0 +} + +unsafe fn fse_decompress_using_dtable_generic( + dst: *mut u8, + max_dst_size: usize, + c_src: *const u8, + c_src_size: usize, + dt: *const u32, + fast: bool, +) -> usize { + let ostart = dst; + let mut op = ostart; + let omax_addr = (op as usize).wrapping_add(max_dst_size); + let olimit_addr = omax_addr.wrapping_sub(3); + + let mut bit_d = FseDStream { + bit_container: 0, + bits_consumed: 0, + ptr: ptr::null(), + start: ptr::null(), + }; + let mut state1 = FseDState { + state: 0, + table: ptr::null(), + }; + let mut state2 = FseDState { + state: 0, + table: ptr::null(), + }; + + /* Init */ + let error_code = fse_init_dstream(&mut bit_d, c_src, c_src_size); + if fse_is_error(error_code) { + return error_code; + } + + fse_init_dstate(&mut state1, &mut bit_d, dt); + fse_init_dstate(&mut state2, &mut bit_d, dt); + + macro_rules! fse_getsymbol { + ($state:expr) => { + if fast { + fse_decode_symbol_fast($state, &mut bit_d) + } else { + fse_decode_symbol($state, &mut bit_d) + } + }; + } + + /* Constant conditions from the C source; on 64-bit both are false, on + * 32-bit only the *4 variant reloads. */ + const RELOAD_2: bool = FSE_MAX_TABLELOG * 2 + 7 > USIZE_BITS; + const RELOAD_4: bool = FSE_MAX_TABLELOG * 4 + 7 > USIZE_BITS; + + /* 4 symbols per loop */ + while fse_reload_dstream(&mut bit_d) == FSE_DSTREAM_UNFINISHED && (op as usize) < olimit_addr { + *op = fse_getsymbol!(&mut state1); + + if RELOAD_2 { + /* This test must be static */ + fse_reload_dstream(&mut bit_d); + } + + *op.add(1) = fse_getsymbol!(&mut state2); + + if RELOAD_4 { + /* This test must be static */ + if fse_reload_dstream(&mut bit_d) > FSE_DSTREAM_UNFINISHED { + op = op.add(2); + break; + } + } + + *op.add(2) = fse_getsymbol!(&mut state1); + + if RELOAD_2 { + /* This test must be static */ + fse_reload_dstream(&mut bit_d); + } + + *op.add(3) = fse_getsymbol!(&mut state2); + op = op.add(4); + } + + /* tail */ + loop { + if fse_reload_dstream(&mut bit_d) > FSE_DSTREAM_COMPLETED + || (op as usize) == omax_addr + || (fse_end_of_dstream(&bit_d) && (fast || fse_end_of_dstate(&state1))) + { + break; + } + + *op = fse_getsymbol!(&mut state1); + op = op.add(1); + + if fse_reload_dstream(&mut bit_d) > FSE_DSTREAM_COMPLETED + || (op as usize) == omax_addr + || (fse_end_of_dstream(&bit_d) && (fast || fse_end_of_dstate(&state2))) + { + break; + } + + *op = fse_getsymbol!(&mut state2); + op = op.add(1); + } + + /* end ? */ + if fse_end_of_dstream(&bit_d) && fse_end_of_dstate(&state1) && fse_end_of_dstate(&state2) { + return (op as usize) - (ostart as usize); + } + + if (op as usize) == omax_addr { + /* dst buffer is full, but cSrc unfinished */ + return fse_error(FSE_ERROR_DST_SIZE_TOO_SMALL); + } + + fse_error(FSE_ERROR_CORRUPTION_DETECTED) +} + +unsafe fn fse_decompress_using_dtable( + dst: *mut u8, + original_size: usize, + c_src: *const u8, + c_src_size: usize, + dt: *const u32, +) -> usize { + let fast_mode = (*(dt as *const FseDTableHeader)).fast_mode; + + /* select fast mode (static) */ + if fast_mode != 0 { + return fse_decompress_using_dtable_generic( + dst, + original_size, + c_src, + c_src_size, + dt, + true, + ); + } + fse_decompress_using_dtable_generic(dst, original_size, c_src, c_src_size, dt, false) +} + +unsafe fn fse_decompress( + dst: *mut u8, + max_dst_size: usize, + c_src: *const u8, + c_src_size: usize, +) -> usize { + let istart = c_src; + let mut ip = istart; + let mut counting = [0i16; (FSE_MAX_SYMBOL_VALUE + 1) as usize]; + let mut dt = [0u32; 1 + (1 << FSE_MAX_TABLELOG)]; /* DTable_max_t */ + let mut table_log: u32 = 0; + let mut max_symbol_value: u32 = FSE_MAX_SYMBOL_VALUE; + let mut remaining_size = c_src_size; + + if c_src_size < 2 { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); /* too small input size */ + } + + /* normal FSE decoding mode */ + let error_code = fse_read_ncount( + counting.as_mut_ptr(), + &mut max_symbol_value, + &mut table_log, + istart, + c_src_size, + ); + if fse_is_error(error_code) { + return error_code; + } + if error_code >= c_src_size { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); /* too small input size */ + } + ip = ip.add(error_code); + remaining_size -= error_code; + + let error_code = fse_build_dtable( + dt.as_mut_ptr(), + counting.as_ptr(), + max_symbol_value, + table_log, + ); + if fse_is_error(error_code) { + return error_code; + } + + /* always return, even if it is an error code */ + fse_decompress_using_dtable(dst, max_dst_size, ip, remaining_size, dt.as_ptr()) +} + +/* ****************************************** + * Huff0 : Huffman block decompression + ********************************************/ +#[repr(C)] +#[derive(Clone, Copy)] +struct HufDElt { + byte: u8, + nb_bits: u8, +} + +/* Loop shapes and arithmetic below intentionally mirror the frozen C. */ +#[allow(clippy::needless_range_loop, clippy::manual_div_ceil)] +unsafe fn huf_read_dtable(dtable: *mut u16, src: *const u8, src_size: usize) -> usize { + let mut huff_weight = [0u8; (HUF_MAX_SYMBOL_VALUE + 1) as usize]; + let mut rank_val = [0u32; (HUF_ABSOLUTEMAX_TABLELOG + 1) as usize]; + let ip = src; + let dt = dtable.add(1) as *mut HufDElt; + + if src_size == 0 { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + let mut i_size = *ip as usize; + + let o_size: usize; + if i_size >= 128 { + /* special header */ + if i_size >= 242 { + /* RLE */ + const L: [usize; 14] = [1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128]; + o_size = L[i_size - 242]; + huff_weight = [1u8; (HUF_MAX_SYMBOL_VALUE + 1) as usize]; + i_size = 0; + } else { + /* Incompressible */ + o_size = i_size - 127; + i_size = (o_size + 1) / 2; + if i_size + 1 > src_size { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + let ip = ip.add(1); + let mut n = 0usize; + while n < o_size { + huff_weight[n] = *ip.add(n / 2) >> 4; + huff_weight[n + 1] = *ip.add(n / 2) & 15; + n += 2; + } + } + } else { + /* header compressed with FSE (normal case) */ + if i_size + 1 > src_size { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + /* max 255 values decoded, last one is implied */ + let decoded = fse_decompress( + huff_weight.as_mut_ptr(), + HUF_MAX_SYMBOL_VALUE as usize, + ip.add(1), + i_size, + ); + if fse_is_error(decoded) { + return decoded; + } + o_size = decoded; + } + + /* collect weight stats */ + let mut weight_total: u32 = 0; + for n in 0..o_size { + if huff_weight[n] >= HUF_ABSOLUTEMAX_TABLELOG as u8 { + return fse_error(FSE_ERROR_CORRUPTION_DETECTED); + } + rank_val[huff_weight[n] as usize] += 1; + weight_total += (1u32 << huff_weight[n]) >> 1; + } + if weight_total == 0 { + return fse_error(FSE_ERROR_CORRUPTION_DETECTED); + } + + /* get last non-null symbol weight (implied, total must be 2^n) */ + let max_bits = fse_highbit32(weight_total) + 1; + if max_bits > *dtable as u32 { + return fse_error(FSE_ERROR_TABLELOG_TOO_LARGE); /* DTable is too small */ + } + *dtable = max_bits as u16; + { + let total = 1u32 << max_bits; + let rest = total - weight_total; + let verif = 1u32 << fse_highbit32(rest); + let last_weight = fse_highbit32(rest) + 1; + if verif != rest { + return fse_error(FSE_ERROR_CORRUPTION_DETECTED); /* last value must be a clean power of 2 */ + } + huff_weight[o_size] = last_weight as u8; + rank_val[last_weight as usize] += 1; + } + + /* check tree construction validity */ + if rank_val[1] < 2 || (rank_val[1] & 1) != 0 { + /* by construction : at least 2 elts of rank 1, must be even */ + return fse_error(FSE_ERROR_CORRUPTION_DETECTED); + } + + /* Prepare ranks */ + let mut next_rank_start: u32 = 0; + for n in 1..=(max_bits as usize) { + let current = next_rank_start; + next_rank_start += rank_val[n] << (n - 1); + rank_val[n] = current; + } + + /* fill DTable */ + for n in 0..=o_size { + let w = huff_weight[n] as usize; + let length = (1u32 << w) >> 1; + let d = HufDElt { + byte: n as u8, + nb_bits: (max_bits + 1 - w as u32) as u8, + }; + for i in rank_val[w]..(rank_val[w] + length) { + *dt.add(i as usize) = d; + } + rank_val[w] += length; + } + + i_size + 1 +} + +unsafe fn huf_decode_symbol(d_stream: &mut FseDStream, dt: *const HufDElt, dt_log: u32) -> u8 { + let val = fse_look_bits_fast(d_stream, dt_log); /* note : dtLog >= 1 */ + let entry = *dt.add(val); + fse_skip_bits(d_stream, entry.nb_bits as u32); + entry.byte +} + +/* The C decode macros: SYMBOL_1 reloads on 32-bit only when + * HUF_MAX_TABLELOG > 12 (never here); SYMBOL_2 reloads on 32-bit. */ +#[inline] +unsafe fn huf_decode_symbol_1( + op: *mut u8, + d_stream: &mut FseDStream, + dt: *const HufDElt, + dt_log: u32, +) { + *op = huf_decode_symbol(d_stream, dt, dt_log); + if IS_32BITS && HUF_MAX_TABLELOG > 12 { + fse_reload_dstream(d_stream); + } +} + +#[inline] +unsafe fn huf_decode_symbol_2( + op: *mut u8, + d_stream: &mut FseDStream, + dt: *const HufDElt, + dt_log: u32, +) { + *op = huf_decode_symbol(d_stream, dt, dt_log); + if IS_32BITS { + fse_reload_dstream(d_stream); + } +} + +unsafe fn huf_decompress_using_dtable( + dst: *mut u8, + max_dst_size: usize, + c_src: *const u8, + c_src_size: usize, + dtable: *const u16, +) -> usize { + if c_src_size < 6 { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + + let ostart = dst; + let mut op = ostart; + let omax_addr = (op as usize).wrapping_add(max_dst_size); + let olimit_addr = if max_dst_size < 15 { + op as usize + } else { + omax_addr - 15 + }; + + let dt = dtable.add(1) as *const HufDElt; + let dt_log = *dtable as u32; + + /* Init */ + let length1 = fse_read_le16(c_src) as usize; + let length2 = fse_read_le16(c_src.add(2)) as usize; + let length3 = fse_read_le16(c_src.add(4)) as usize; + let length4 = c_src_size + .wrapping_sub(6) + .wrapping_sub(length1) + .wrapping_sub(length2) + .wrapping_sub(length3); /* check coherency !! */ + let start1 = c_src.add(6); + let start2 = start1.wrapping_add(length1); + let start3 = start2.wrapping_add(length2); + let start4 = start3.wrapping_add(length3); + + if length1 + length2 + length3 + 6 >= c_src_size { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + + let mut bit_d1 = FseDStream { + bit_container: 0, + bits_consumed: 0, + ptr: ptr::null(), + start: ptr::null(), + }; + let mut bit_d2 = FseDStream { + bit_container: 0, + bits_consumed: 0, + ptr: ptr::null(), + start: ptr::null(), + }; + let mut bit_d3 = FseDStream { + bit_container: 0, + bits_consumed: 0, + ptr: ptr::null(), + start: ptr::null(), + }; + let mut bit_d4 = FseDStream { + bit_container: 0, + bits_consumed: 0, + ptr: ptr::null(), + start: ptr::null(), + }; + + let error_code = fse_init_dstream(&mut bit_d1, start1, length1); + if fse_is_error(error_code) { + return error_code; + } + let error_code = fse_init_dstream(&mut bit_d2, start2, length2); + if fse_is_error(error_code) { + return error_code; + } + let error_code = fse_init_dstream(&mut bit_d3, start3, length3); + if fse_is_error(error_code) { + return error_code; + } + let error_code = fse_init_dstream(&mut bit_d4, start4, length4); + if fse_is_error(error_code) { + return error_code; + } + + let mut reload_status = fse_reload_dstream(&mut bit_d2); + + /* 16 symbols per loop; D2-3-4 are supposed to be synchronized and finish together */ + while reload_status < FSE_DSTREAM_COMPLETED && (op as usize) < olimit_addr { + huf_decode_symbol_1(op, &mut bit_d1, dt, dt_log); + huf_decode_symbol_1(op.add(1), &mut bit_d2, dt, dt_log); + huf_decode_symbol_1(op.add(2), &mut bit_d3, dt, dt_log); + huf_decode_symbol_1(op.add(3), &mut bit_d4, dt, dt_log); + huf_decode_symbol_2(op.add(4), &mut bit_d1, dt, dt_log); + huf_decode_symbol_2(op.add(5), &mut bit_d2, dt, dt_log); + huf_decode_symbol_2(op.add(6), &mut bit_d3, dt, dt_log); + huf_decode_symbol_2(op.add(7), &mut bit_d4, dt, dt_log); + huf_decode_symbol_1(op.add(8), &mut bit_d1, dt, dt_log); + huf_decode_symbol_1(op.add(9), &mut bit_d2, dt, dt_log); + huf_decode_symbol_1(op.add(10), &mut bit_d3, dt, dt_log); + huf_decode_symbol_1(op.add(11), &mut bit_d4, dt, dt_log); + *op.add(12) = huf_decode_symbol(&mut bit_d1, dt, dt_log); + *op.add(13) = huf_decode_symbol(&mut bit_d2, dt, dt_log); + *op.add(14) = huf_decode_symbol(&mut bit_d3, dt, dt_log); + *op.add(15) = huf_decode_symbol(&mut bit_d4, dt, dt_log); + + op = op.add(16); + reload_status = fse_reload_dstream(&mut bit_d2) + | fse_reload_dstream(&mut bit_d3) + | fse_reload_dstream(&mut bit_d4); + fse_reload_dstream(&mut bit_d1); + } + + if reload_status != FSE_DSTREAM_COMPLETED { + /* not complete : some bitStream might be FSE_DStream_unfinished */ + return fse_error(FSE_ERROR_CORRUPTION_DETECTED); + } + + /* tail */ + { + let mut bit_tail = FseDStream { + bit_container: bit_d1.bit_container, /* required in case of FSE_DStream_endOfBuffer */ + bits_consumed: bit_d1.bits_consumed, + ptr: bit_d1.ptr, + start: start1, + }; + while fse_reload_dstream(&mut bit_tail) < FSE_DSTREAM_COMPLETED && (op as usize) < omax_addr + { + *op = huf_decode_symbol(&mut bit_tail, dt, dt_log); + op = op.add(1); + } + + if fse_end_of_dstream(&bit_tail) { + return (op as usize) - (ostart as usize); + } + } + + if (op as usize) == omax_addr { + return fse_error(FSE_ERROR_DST_SIZE_TOO_SMALL); /* dst buffer is full, but cSrc unfinished */ + } + + fse_error(FSE_ERROR_CORRUPTION_DETECTED) +} + +unsafe fn huf_decompress( + dst: *mut u8, + max_dst_size: usize, + c_src: *const u8, + c_src_size: usize, +) -> usize { + /* HUF_CREATE_STATIC_DTABLE(DTable, HUF_MAX_TABLELOG) */ + let mut dtable = [0u16; 1 + (1 << HUF_MAX_TABLELOG)]; + dtable[0] = HUF_MAX_TABLELOG as u16; + let mut ip = c_src; + + let error_code = huf_read_dtable(dtable.as_mut_ptr(), c_src, c_src_size); + if fse_is_error(error_code) { + return error_code; + } + if error_code >= c_src_size { + return fse_error(FSE_ERROR_SRC_SIZE_WRONG); + } + ip = ip.add(error_code); + + huf_decompress_using_dtable( + dst, + max_dst_size, + ip, + c_src_size - error_code, + dtable.as_ptr(), + ) +} + +/* ****************************************** + * zstd v0.1 frame decoding + ********************************************/ +const ZSTD_MAGIC_NUMBER: u32 = 0xFD2FB51E; /* 3rd version : seqNb header */ + +const KB: usize = 1 << 10; +const BLOCKSIZE: usize = 128 * KB; /* define, for static allocation */ + +const MINMATCH: usize = 4; +const MLBITS: u32 = 7; +const LLBITS: u32 = 6; +const OFFBITS: u32 = 5; +const MAX_ML: u32 = (1 << MLBITS) - 1; +const MAX_LL: u32 = (1 << LLBITS) - 1; +const MAX_OFF: u32 = (1 << OFFBITS) - 1; +#[allow(dead_code)] /* part of the frozen v0.1 constant set; used only by the compressor */ +const LIT_FSE_LOG: u32 = 11; +const ML_FSE_LOG: u32 = 10; +const LL_FSE_LOG: u32 = 10; +const OFF_FSE_LOG: u32 = 9; + +const ZSTD_CONTENTSIZE_ERROR: u64 = 0u64.wrapping_sub(2); + +const ZSTD_BLOCK_HEADER_SIZE: usize = 3; +const ZSTD_FRAME_HEADER_SIZE: usize = 4; + +/* FSE_DTABLE_SIZE_U32(maxTableLog) == 1 + (1 << maxTableLog) */ +const LL_DTABLE_SIZE_U32: usize = 1 + (1 << LL_FSE_LOG as usize); +const OFF_DTABLE_SIZE_U32: usize = 1 + (1 << OFF_FSE_LOG as usize); +const ML_DTABLE_SIZE_U32: usize = 1 + (1 << ML_FSE_LOG as usize); + +#[inline] +unsafe fn zstd_copy4(dst: *mut u8, src: *const u8) { + ptr::copy_nonoverlapping(src, dst, 4); +} + +#[inline] +unsafe fn zstd_copy8(dst: *mut u8, src: *const u8) { + ptr::copy_nonoverlapping(src, dst, 8); +} + +unsafe fn zstd_wildcopy(dst: *mut u8, src: *const u8, length: isize) { + let mut ip = src; + let mut op = dst; + let oend_addr = (op as usize).wrapping_add(length as usize); + while (op as usize) < oend_addr { + zstd_copy8(op, ip); + op = op.add(8); + ip = ip.add(8); + } +} + +#[inline] +unsafe fn zstd_read_le16(mem_ptr: *const u8) -> u16 { + u16::from_le_bytes(ptr::read_unaligned(mem_ptr as *const [u8; 2])) +} + +#[inline] +unsafe fn zstd_read_le24(mem_ptr: *const u8) -> u32 { + zstd_read_le16(mem_ptr) as u32 + ((*mem_ptr.add(2) as u32) << 16) +} + +#[inline] +unsafe fn zstd_read_be32(mem_ptr: *const u8) -> u32 { + u32::from_be_bytes(ptr::read_unaligned(mem_ptr as *const [u8; 4])) +} + +/* blockType_t */ +const BT_COMPRESSED: u32 = 0; +const BT_RAW: u32 = 1; +const BT_RLE: u32 = 2; +const BT_END: u32 = 3; + +struct BlockProperties { + block_type: u32, + orig_size: u32, +} + +/// The v0.1 streaming decompression context (`dctx_t` in C). The struct is +/// opaque to C: `zstd_v01.h` only forward-declares it, so the definition now +/// lives here. +#[repr(C)] +pub struct ZSTDv01_Dctx { + ll_table: [u32; LL_DTABLE_SIZE_U32], + off_table: [u32; OFF_DTABLE_SIZE_U32], + ml_table: [u32; ML_DTABLE_SIZE_U32], + previous_dst_end: *const u8, + base: *const u8, + expected: usize, + b_type: u32, + phase: u32, +} + +unsafe fn zstdv01_getc_block_size( + src: *const u8, + src_size: usize, + bp_ptr: &mut BlockProperties, +) -> usize { + if src_size < 3 { + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + + let header_flags = *src; + let c_size = + (*src.add(2) as u32) + ((*src.add(1) as u32) << 8) + (((header_flags & 7) as u32) << 16); + + bp_ptr.block_type = (header_flags >> 6) as u32; + bp_ptr.orig_size = if bp_ptr.block_type == BT_RLE { + c_size + } else { + 0 + }; + + if bp_ptr.block_type == BT_END { + return 0; + } + if bp_ptr.block_type == BT_RLE { + return 1; + } + c_size as usize +} + +unsafe fn zstd_copy_uncompressed_block( + dst: *mut u8, + max_dst_size: usize, + src: *const u8, + src_size: usize, +) -> usize { + if src_size > max_dst_size { + return ERROR(ZstdErrorCode::DstSizeTooSmall); + } + if src_size > 0 { + ptr::copy_nonoverlapping(src, dst, src_size); + } + src_size +} + +unsafe fn zstd_decompress_literals( + dst: *mut u8, + max_dst_size: usize, + src: *const u8, + src_size: usize, +) -> usize { + let oend = dst.add(max_dst_size); + let ip = src; + + /* check : minimum 2, for litSize, +1, for content */ + if src_size <= 3 { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + + let mut lit_size = (*ip.add(1) as usize) + ((*ip as usize) << 8); + lit_size += (((*ip.offset(-3) as usize) >> 3) & 7) << 16; /* mmmmh.... */ + + if lit_size > max_dst_size { + return ERROR(ZstdErrorCode::DstSizeTooSmall); + } + let op = oend.sub(lit_size); + let error_code = huf_decompress(op, lit_size, ip.add(2), src_size - 2); + if fse_is_error(error_code) { + return ERROR(ZstdErrorCode::Generic); + } + lit_size +} + +unsafe fn zstdv01_decode_literals_block( + dst: *mut u8, + max_dst_size: usize, + lit_start: &mut *const u8, + lit_size: &mut usize, + src: *const u8, + src_size: usize, +) -> usize { + let istart = src; + let mut ip = istart; + let ostart = dst; + let oend = ostart.add(max_dst_size); + let mut litbp = BlockProperties { + block_type: 0, + orig_size: 0, + }; + + let litc_size = zstdv01_getc_block_size(src, src_size, &mut litbp); + if ERR_isError(litc_size) { + return litc_size; + } + if litc_size > src_size - ZSTD_BLOCK_HEADER_SIZE { + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + ip = ip.add(ZSTD_BLOCK_HEADER_SIZE); + + match litbp.block_type { + BT_RAW => { + *lit_start = ip; + ip = ip.add(litc_size); + *lit_size = litc_size; + } + BT_RLE => { + let rle_size = litbp.orig_size as usize; + if rle_size > max_dst_size { + return ERROR(ZstdErrorCode::DstSizeTooSmall); + } + if src_size == 0 { + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + if rle_size > 0 { + ptr::write_bytes(oend.sub(rle_size), *ip, rle_size); + } + *lit_start = oend.sub(rle_size); + *lit_size = rle_size; + ip = ip.add(1); + } + BT_COMPRESSED => { + let decoded_lit_size = zstd_decompress_literals(dst, max_dst_size, ip, litc_size); + if ERR_isError(decoded_lit_size) { + return decoded_lit_size; + } + *lit_start = oend.sub(decoded_lit_size); + *lit_size = decoded_lit_size; + ip = ip.add(litc_size); + } + _ => { + /* bt_end and impossible values */ + return ERROR(ZstdErrorCode::Generic); + } + } + + (ip as usize) - (istart as usize) +} + +#[allow(clippy::too_many_arguments)] +unsafe fn zstdv01_decode_seq_headers( + nb_seq: &mut i32, + dumps_ptr: &mut *const u8, + dumps_length_ptr: &mut usize, + dtable_ll: *mut u32, + dtable_ml: *mut u32, + dtable_offb: *mut u32, + src: *const u8, + src_size: usize, +) -> usize { + let istart = src; + let mut ip = istart; + let iend_addr = (istart as usize).wrapping_add(src_size); + + /* check */ + if src_size < 5 { + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + + /* SeqHead */ + *nb_seq = zstd_read_le16(ip) as i32; + ip = ip.add(2); + let ll_type = (*ip >> 6) as u32; + let off_type = ((*ip >> 4) & 3) as u32; + let ml_type = ((*ip >> 2) & 3) as u32; + let dumps_length: usize; + if (*ip & 2) != 0 { + dumps_length = (*ip.add(2) as usize) + ((*ip.add(1) as usize) << 8); + ip = ip.add(3); + } else { + dumps_length = (*ip.add(1) as usize) + (((*ip as usize) & 1) << 8); + ip = ip.add(2); + } + *dumps_ptr = ip; + ip = ip.wrapping_add(dumps_length); + *dumps_length_ptr = dumps_length; + + /* check */ + if (ip as usize) > iend_addr.wrapping_sub(3) { + /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */ + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + + /* sequences */ + { + let mut norm = [0i16; (MAX_ML + 1) as usize]; /* assumption : MaxML >= MaxLL and MaxOff */ + + /* Build DTables */ + match ll_type { + BT_RLE => { + fse_build_dtable_rle(dtable_ll, *ip); + ip = ip.add(1); + } + BT_RAW => { + fse_build_dtable_raw(dtable_ll, LLBITS); + } + _ => { + let mut max = MAX_LL; + let mut ll_log = 0u32; + let header_size = fse_read_ncount( + norm.as_mut_ptr(), + &mut max, + &mut ll_log, + ip, + iend_addr - ip as usize, + ); + if fse_is_error(header_size) { + return ERROR(ZstdErrorCode::Generic); + } + if ll_log > LL_FSE_LOG { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + ip = ip.add(header_size); + fse_build_dtable(dtable_ll, norm.as_ptr(), max, ll_log); + } + } + + match off_type { + BT_RLE => { + if (ip as usize) > iend_addr.wrapping_sub(2) { + /* min : "raw", hence no header, but at least xxLog bits */ + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + fse_build_dtable_rle(dtable_offb, *ip); + ip = ip.add(1); + } + BT_RAW => { + fse_build_dtable_raw(dtable_offb, OFFBITS); + } + _ => { + let mut max = MAX_OFF; + let mut off_log = 0u32; + let header_size = fse_read_ncount( + norm.as_mut_ptr(), + &mut max, + &mut off_log, + ip, + iend_addr - ip as usize, + ); + if fse_is_error(header_size) { + return ERROR(ZstdErrorCode::Generic); + } + if off_log > OFF_FSE_LOG { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + ip = ip.add(header_size); + fse_build_dtable(dtable_offb, norm.as_ptr(), max, off_log); + } + } + + match ml_type { + BT_RLE => { + if (ip as usize) > iend_addr.wrapping_sub(2) { + /* min : "raw", hence no header, but at least xxLog bits */ + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + fse_build_dtable_rle(dtable_ml, *ip); + ip = ip.add(1); + } + BT_RAW => { + fse_build_dtable_raw(dtable_ml, MLBITS); + } + _ => { + let mut max = MAX_ML; + let mut ml_log = 0u32; + let header_size = fse_read_ncount( + norm.as_mut_ptr(), + &mut max, + &mut ml_log, + ip, + iend_addr - ip as usize, + ); + if fse_is_error(header_size) { + return ERROR(ZstdErrorCode::Generic); + } + if ml_log > ML_FSE_LOG { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + ip = ip.add(header_size); + fse_build_dtable(dtable_ml, norm.as_ptr(), max, ml_log); + } + } + } + + (ip as usize) - (istart as usize) +} + +#[derive(Clone, Copy)] +struct Seq { + lit_length: usize, + offset: usize, + match_length: usize, +} + +struct SeqState { + d_stream: FseDStream, + state_ll: FseDState, + state_offb: FseDState, + state_ml: FseDState, + prev_offset: usize, + dumps: *const u8, + dumps_end: *const u8, +} + +unsafe fn zstd_decode_sequence(seq: &mut Seq, seq_state: &mut SeqState) { + let mut dumps = seq_state.dumps; + let de = seq_state.dumps_end; + + /* Literal length */ + let mut lit_length = + fse_decode_symbol(&mut seq_state.state_ll, &mut seq_state.d_stream) as usize; + let prev_offset = if lit_length != 0 { + seq.offset + } else { + seq_state.prev_offset + }; + seq_state.prev_offset = seq.offset; + if lit_length == MAX_LL as usize { + let add = if (dumps as usize) < (de as usize) { + let v = *dumps as u32; + dumps = dumps.add(1); + v + } else { + 0 + }; + if add < 255 { + lit_length += add as usize; + } else if (dumps as usize) <= (de as usize).wrapping_sub(3) { + lit_length = zstd_read_le24(dumps) as usize; + dumps = dumps.add(3); + } + } + + /* Offset */ + let mut offset: usize; + { + let offset_code = + fse_decode_symbol(&mut seq_state.state_offb, &mut seq_state.d_stream) as u32; + if IS_32BITS { + fse_reload_dstream(&mut seq_state.d_stream); + } + let mut nb_bits = offset_code.wrapping_sub(1); + if offset_code == 0 { + nb_bits = 0; /* cmove */ + } + offset = (1usize << (nb_bits & (USIZE_BITS - 1))) + .wrapping_add(fse_read_bits(&mut seq_state.d_stream, nb_bits)); + if IS_32BITS { + fse_reload_dstream(&mut seq_state.d_stream); + } + if offset_code == 0 { + offset = prev_offset; + } + } + + /* MatchLength */ + let mut match_length = + fse_decode_symbol(&mut seq_state.state_ml, &mut seq_state.d_stream) as usize; + if match_length == MAX_ML as usize { + let add = if (dumps as usize) < (de as usize) { + let v = *dumps as u32; + dumps = dumps.add(1); + v + } else { + 0 + }; + if add < 255 { + match_length += add as usize; + } else if (dumps as usize) <= (de as usize).wrapping_sub(3) { + match_length = zstd_read_le24(dumps) as usize; + dumps = dumps.add(3); + } + } + match_length += MINMATCH; + + /* save result */ + seq.lit_length = lit_length; + seq.offset = offset; + seq.match_length = match_length; + seq_state.dumps = dumps; +} + +unsafe fn zstd_exec_sequence( + op: *mut u8, + sequence: Seq, + lit_ptr: &mut *const u8, + lit_limit: *const u8, + base: *const u8, + oend: *mut u8, +) -> usize { + static DEC32TABLE: [usize; 8] = [0, 1, 2, 1, 4, 4, 4, 4]; /* added */ + static DEC64TABLE: [usize; 8] = [8, 8, 8, 7, 8, 9, 10, 11]; /* subtracted */ + let ostart = op; + let mut op = op; + let o_lit_end = op.wrapping_add(sequence.lit_length); + let lit_length = sequence.lit_length; + /* risk : address space overflow (32-bits) */ + let end_match = op + .wrapping_add(lit_length) + .wrapping_add(sequence.match_length); + let lit_end = (*lit_ptr).wrapping_add(lit_length); + + /* checks */ + let seq_length = sequence.lit_length.wrapping_add(sequence.match_length); + + if seq_length > (oend as usize).wrapping_sub(op as usize) { + return ERROR(ZstdErrorCode::DstSizeTooSmall); + } + if sequence.lit_length > (lit_limit as usize).wrapping_sub(*lit_ptr as usize) { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + /* Now we know there are no overflow in literal nor match lengths, can use pointer checks */ + if sequence.offset > ((o_lit_end as usize).wrapping_sub(base as usize)) as u32 as usize { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + + if (end_match as usize) > (oend as usize) { + /* overwrite beyond dst buffer */ + return ERROR(ZstdErrorCode::DstSizeTooSmall); + } + if (lit_end as usize) > (lit_limit as usize) { + /* overRead beyond lit buffer */ + return ERROR(ZstdErrorCode::CorruptionDetected); + } + if sequence.match_length > (*lit_ptr as usize).wrapping_sub(op as usize) { + /* overwrite literal segment */ + return ERROR(ZstdErrorCode::DstSizeTooSmall); + } + + /* copy Literals */ + /* note : v0.1 seems to allow scenarios where output or input are close to end of buffer */ + ptr::copy(*lit_ptr, op, sequence.lit_length); + + op = op.add(lit_length); + *lit_ptr = lit_end; /* update for next sequence */ + + /* check : last match must be at a minimum distance of 8 from end of dest buffer */ + if (oend as usize) - (op as usize) < 8 { + return ERROR(ZstdErrorCode::DstSizeTooSmall); + } + + /* copy Match */ + { + let overlap_risk = (lit_end as usize).wrapping_sub(end_match as usize) < 12; + /* possible underflow at op - offset ? */ + let mut match_ptr = (op as usize).wrapping_sub(sequence.offset) as *const u8; + let mut qutt: usize = 12; + let mut saved = [0u8; 16]; /* U64 saved[2] */ + + /* check */ + if (match_ptr as usize) < (base as usize) { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + if sequence.offset > base as usize { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + + /* save beginning of literal sequence, in case of write overlap */ + if overlap_risk { + if (end_match as usize).wrapping_add(qutt) > (oend as usize) { + qutt = (oend as usize) - (end_match as usize); + } + ptr::copy_nonoverlapping(end_match as *const u8, saved.as_mut_ptr(), qutt); + } + + if sequence.offset < 8 { + let dec64 = DEC64TABLE[sequence.offset]; + *op = *match_ptr; + *op.add(1) = *match_ptr.add(1); + *op.add(2) = *match_ptr.add(2); + *op.add(3) = *match_ptr.add(3); + match_ptr = match_ptr.add(DEC32TABLE[sequence.offset]); + zstd_copy4(op.add(4), match_ptr); + match_ptr = match_ptr.sub(dec64); + } else { + zstd_copy8(op, match_ptr); + } + op = op.add(8); + match_ptr = match_ptr.add(8); + + if (end_match as usize) > (oend as usize).wrapping_sub(16 - MINMATCH) { + if (op as usize) < (oend as usize).wrapping_sub(8) { + let dist = ((oend as usize) - 8) - (op as usize); + zstd_wildcopy(op, match_ptr, dist as isize); + match_ptr = match_ptr.add(dist); + op = oend.sub(8); + } + while (op as usize) < (end_match as usize) { + *op = *match_ptr; + op = op.add(1); + match_ptr = match_ptr.add(1); + } + } else { + /* works even if matchLength < 8 */ + zstd_wildcopy(op, match_ptr, sequence.match_length as isize - 8); + } + + /* restore, in case of overlap */ + if overlap_risk { + ptr::copy_nonoverlapping(saved.as_ptr(), end_match, qutt); + } + } + + (end_match as usize) - (ostart as usize) +} + +unsafe fn zstd_decompress_sequences( + ctx: *mut ZSTDv01_Dctx, + dst: *mut u8, + max_dst_size: usize, + seq_start: *const u8, + seq_size: usize, + lit_start: *const u8, + lit_size: usize, +) -> usize { + let dctx = ctx; + let mut ip = seq_start; + let iend_addr = (ip as usize).wrapping_add(seq_size); + let ostart = dst; + let mut op = ostart; + let oend = ostart.add(max_dst_size); + let mut lit_ptr = lit_start; + let lit_end = lit_start.add(lit_size); + let mut nb_seq: i32 = 0; + let mut dumps: *const u8 = ptr::null(); + let mut dumps_length: usize = 0; + let dtable_ll = (*dctx).ll_table.as_mut_ptr(); + let dtable_ml = (*dctx).ml_table.as_mut_ptr(); + let dtable_offb = (*dctx).off_table.as_mut_ptr(); + let base = (*dctx).base; + + /* Build Decoding Tables */ + let error_code = zstdv01_decode_seq_headers( + &mut nb_seq, + &mut dumps, + &mut dumps_length, + dtable_ll, + dtable_ml, + dtable_offb, + ip, + iend_addr - ip as usize, + ); + if ERR_isError(error_code) { + return error_code; + } + ip = ip.add(error_code); + + /* Regen sequences */ + { + let mut sequence = Seq { + lit_length: 0, + offset: 0, + match_length: 0, + }; + let mut seq_state = SeqState { + d_stream: FseDStream { + bit_container: 0, + bits_consumed: 0, + ptr: ptr::null(), + start: ptr::null(), + }, + state_ll: FseDState { + state: 0, + table: ptr::null(), + }, + state_offb: FseDState { + state: 0, + table: ptr::null(), + }, + state_ml: FseDState { + state: 0, + table: ptr::null(), + }, + prev_offset: 1, + dumps, + dumps_end: dumps.wrapping_add(dumps_length), + }; + let error_code = fse_init_dstream(&mut seq_state.d_stream, ip, iend_addr - ip as usize); + if fse_is_error(error_code) { + return ERROR(ZstdErrorCode::CorruptionDetected); + } + fse_init_dstate(&mut seq_state.state_ll, &mut seq_state.d_stream, dtable_ll); + fse_init_dstate( + &mut seq_state.state_offb, + &mut seq_state.d_stream, + dtable_offb, + ); + fse_init_dstate(&mut seq_state.state_ml, &mut seq_state.d_stream, dtable_ml); + + while fse_reload_dstream(&mut seq_state.d_stream) <= FSE_DSTREAM_COMPLETED && nb_seq > 0 { + nb_seq -= 1; + zstd_decode_sequence(&mut sequence, &mut seq_state); + let one_seq_size = zstd_exec_sequence(op, sequence, &mut lit_ptr, lit_end, base, oend); + if ERR_isError(one_seq_size) { + return one_seq_size; + } + op = op.add(one_seq_size); + } + + /* check if reached exact end */ + if !fse_end_of_dstream(&seq_state.d_stream) { + /* requested too much : data is corrupted */ + return ERROR(ZstdErrorCode::CorruptionDetected); + } + if nb_seq < 0 { + /* requested too many sequences : data is corrupted */ + return ERROR(ZstdErrorCode::CorruptionDetected); + } + + /* last literal segment */ + { + let last_ll_size = (lit_end as usize) - (lit_ptr as usize); + if (op as usize).wrapping_add(last_ll_size) > (oend as usize) { + return ERROR(ZstdErrorCode::DstSizeTooSmall); + } + if last_ll_size > 0 { + if !std::ptr::eq(op as *const u8, lit_ptr) { + ptr::copy(lit_ptr, op, last_ll_size); + } + op = op.add(last_ll_size); + } + } + } + + (op as usize) - (ostart as usize) +} + +unsafe fn zstd_decompress_block( + ctx: *mut ZSTDv01_Dctx, + dst: *mut u8, + max_dst_size: usize, + src: *const u8, + src_size: usize, +) -> usize { + /* blockType == blockCompressed, srcSize is trusted */ + let mut ip = src; + let mut lit_ptr: *const u8 = ptr::null(); + let mut lit_size: usize = 0; + + /* Decode literals sub-block */ + let error_code = zstdv01_decode_literals_block( + dst, + max_dst_size, + &mut lit_ptr, + &mut lit_size, + src, + src_size, + ); + if ERR_isError(error_code) { + return error_code; + } + ip = ip.add(error_code); + let src_size = src_size - error_code; + + zstd_decompress_sequences(ctx, dst, max_dst_size, ip, src_size, lit_ptr, lit_size) +} + +unsafe fn zstdv01_decompress_dctx( + ctx: *mut ZSTDv01_Dctx, + dst: *mut u8, + max_dst_size: usize, + src: *const u8, + src_size: usize, +) -> usize { + let mut ip = src; + let iend_addr = (ip as usize).wrapping_add(src_size); + let ostart = dst; + let mut op = ostart; + let oend_addr = (ostart as usize).wrapping_add(max_dst_size); + let mut remaining_size = src_size; + let mut error_code: usize = 0; + + /* Frame Header */ + if src_size < ZSTD_FRAME_HEADER_SIZE + ZSTD_BLOCK_HEADER_SIZE { + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + let magic_number = zstd_read_be32(src); + if magic_number != ZSTD_MAGIC_NUMBER { + return ERROR(ZstdErrorCode::PrefixUnknown); + } + ip = ip.add(ZSTD_FRAME_HEADER_SIZE); + remaining_size -= ZSTD_FRAME_HEADER_SIZE; + + /* Loop on each block */ + loop { + let mut block_properties = BlockProperties { + block_type: 0, + orig_size: 0, + }; + let block_size = + zstdv01_getc_block_size(ip, iend_addr - ip as usize, &mut block_properties); + if ERR_isError(block_size) { + return block_size; + } + + ip = ip.add(ZSTD_BLOCK_HEADER_SIZE); + remaining_size -= ZSTD_BLOCK_HEADER_SIZE; + if block_size > remaining_size { + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + + match block_properties.block_type { + BT_COMPRESSED => { + error_code = + zstd_decompress_block(ctx, op, oend_addr - op as usize, ip, block_size); + } + BT_RAW => { + error_code = + zstd_copy_uncompressed_block(op, oend_addr - op as usize, ip, block_size); + } + BT_RLE => { + return ERROR(ZstdErrorCode::Generic); /* not yet supported */ + } + BT_END => { + /* end of frame */ + if remaining_size != 0 { + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + } + _ => { + return ERROR(ZstdErrorCode::Generic); + } + } + if block_size == 0 { + break; /* bt_end */ + } + + if ERR_isError(error_code) { + return error_code; + } + op = op.add(error_code); + ip = ip.add(block_size); + remaining_size -= block_size; + } + + (op as usize) - (ostart as usize) +} + +/* ZSTD_errorFrameSizeInfoLegacy() : +assumes `cSize` and `dBound` are _not_ NULL */ +unsafe fn zstd_error_frame_size_info_legacy(c_size: *mut usize, d_bound: *mut u64, ret: usize) { + *c_size = ret; + *d_bound = ZSTD_CONTENTSIZE_ERROR; +} + +/* ****************************************** + * Exported C ABI (zstd_v01.h) + ********************************************/ + +/// C ABI: `ZSTDv01_isError`. +#[no_mangle] +pub extern "C" fn ZSTDv01_isError(code: usize) -> c_uint { + ERR_isError(code) as c_uint +} + +/// C ABI: `ZSTDv01_decompressDCtx`. +#[no_mangle] +pub unsafe extern "C" fn ZSTDv01_decompressDCtx( + ctx: *mut c_void, + dst: *mut c_void, + max_original_size: usize, + src: *const c_void, + compressed_size: usize, +) -> usize { + zstdv01_decompress_dctx( + ctx as *mut ZSTDv01_Dctx, + dst as *mut u8, + max_original_size, + src as *const u8, + compressed_size, + ) +} + +/// C ABI: `ZSTDv01_decompress`. +#[no_mangle] +pub unsafe extern "C" fn ZSTDv01_decompress( + dst: *mut c_void, + max_original_size: usize, + src: *const c_void, + compressed_size: usize, +) -> usize { + /* The C version uses an uninitialized on-stack dctx_t; only `base` is + * read before being written, so a zeroed context is equivalent. */ + let mut ctx = std::mem::MaybeUninit::::zeroed(); + let ctx_ptr = ctx.as_mut_ptr(); + (*ctx_ptr).base = dst as *const u8; + zstdv01_decompress_dctx( + ctx_ptr, + dst as *mut u8, + max_original_size, + src as *const u8, + compressed_size, + ) +} + +/// C ABI: `ZSTDv01_findFrameSizeInfoLegacy`. +#[no_mangle] +pub unsafe extern "C" fn ZSTDv01_findFrameSizeInfoLegacy( + src: *const c_void, + src_size: usize, + c_size: *mut usize, + d_bound: *mut u64, +) { + let mut ip = src as *const u8; + let mut remaining_size = src_size; + let mut nb_blocks: usize = 0; + + /* Frame Header */ + if src_size < ZSTD_FRAME_HEADER_SIZE + ZSTD_BLOCK_HEADER_SIZE { + zstd_error_frame_size_info_legacy(c_size, d_bound, ERROR(ZstdErrorCode::SrcSizeWrong)); + return; + } + let magic_number = zstd_read_be32(src as *const u8); + if magic_number != ZSTD_MAGIC_NUMBER { + zstd_error_frame_size_info_legacy(c_size, d_bound, ERROR(ZstdErrorCode::PrefixUnknown)); + return; + } + ip = ip.add(ZSTD_FRAME_HEADER_SIZE); + remaining_size -= ZSTD_FRAME_HEADER_SIZE; + + /* Loop on each block */ + loop { + let mut block_properties = BlockProperties { + block_type: 0, + orig_size: 0, + }; + let block_size = zstdv01_getc_block_size(ip, remaining_size, &mut block_properties); + if ERR_isError(block_size) { + zstd_error_frame_size_info_legacy(c_size, d_bound, block_size); + return; + } + + ip = ip.add(ZSTD_BLOCK_HEADER_SIZE); + remaining_size -= ZSTD_BLOCK_HEADER_SIZE; + if block_size > remaining_size { + zstd_error_frame_size_info_legacy(c_size, d_bound, ERROR(ZstdErrorCode::SrcSizeWrong)); + return; + } + + if block_size == 0 { + break; /* bt_end */ + } + + ip = ip.add(block_size); + remaining_size -= block_size; + nb_blocks += 1; + } + + *c_size = (ip as usize) - (src as usize); + *d_bound = (nb_blocks * BLOCKSIZE) as u64; +} + +/* ****************************************** + * Streaming Decompression API + ********************************************/ + +/// C ABI: `ZSTDv01_resetDCtx`. +#[no_mangle] +pub unsafe extern "C" fn ZSTDv01_resetDCtx(dctx: *mut ZSTDv01_Dctx) -> usize { + (*dctx).expected = ZSTD_FRAME_HEADER_SIZE; + (*dctx).phase = 0; + (*dctx).previous_dst_end = ptr::null(); + (*dctx).base = ptr::null(); + 0 +} + +/// C ABI: `ZSTDv01_createDCtx`. Allocated with `malloc` exactly like the C +/// implementation, so create/free may be paired across the C/Rust boundary. +#[no_mangle] +pub unsafe extern "C" fn ZSTDv01_createDCtx() -> *mut ZSTDv01_Dctx { + let dctx = libc::malloc(std::mem::size_of::()) as *mut ZSTDv01_Dctx; + if dctx.is_null() { + return ptr::null_mut(); + } + ZSTDv01_resetDCtx(dctx); + dctx +} + +/// C ABI: `ZSTDv01_freeDCtx`. +#[no_mangle] +pub unsafe extern "C" fn ZSTDv01_freeDCtx(dctx: *mut ZSTDv01_Dctx) -> usize { + libc::free(dctx as *mut c_void); + 0 +} + +/// C ABI: `ZSTDv01_nextSrcSizeToDecompress`. +#[no_mangle] +pub unsafe extern "C" fn ZSTDv01_nextSrcSizeToDecompress(dctx: *mut ZSTDv01_Dctx) -> usize { + (*dctx).expected +} + +/// C ABI: `ZSTDv01_decompressContinue`. +#[no_mangle] +pub unsafe extern "C" fn ZSTDv01_decompressContinue( + dctx: *mut ZSTDv01_Dctx, + dst: *mut c_void, + max_dst_size: usize, + src: *const c_void, + src_size: usize, +) -> usize { + let ctx = dctx; + let src = src as *const u8; + let dst = dst as *mut u8; + + /* Sanity check */ + if src_size != (*ctx).expected { + return ERROR(ZstdErrorCode::SrcSizeWrong); + } + if !std::ptr::eq(dst as *const u8, (*ctx).previous_dst_end) { + /* not contiguous */ + (*ctx).base = dst as *const u8; + } + + /* Decompress : frame header */ + if (*ctx).phase == 0 { + /* Check frame magic header */ + let magic_number = zstd_read_be32(src); + if magic_number != ZSTD_MAGIC_NUMBER { + return ERROR(ZstdErrorCode::PrefixUnknown); + } + (*ctx).phase = 1; + (*ctx).expected = ZSTD_BLOCK_HEADER_SIZE; + return 0; + } + + /* Decompress : block header */ + if (*ctx).phase == 1 { + let mut bp = BlockProperties { + block_type: 0, + orig_size: 0, + }; + let block_size = zstdv01_getc_block_size(src, ZSTD_BLOCK_HEADER_SIZE, &mut bp); + if ERR_isError(block_size) { + return block_size; + } + if bp.block_type == BT_END { + (*ctx).expected = 0; + (*ctx).phase = 0; + } else { + (*ctx).expected = block_size; + (*ctx).b_type = bp.block_type; + (*ctx).phase = 2; + } + + return 0; + } + + /* Decompress : block content */ + { + let r_size = match (*ctx).b_type { + BT_COMPRESSED => zstd_decompress_block(ctx, dst, max_dst_size, src, src_size), + BT_RAW => zstd_copy_uncompressed_block(dst, max_dst_size, src, src_size), + BT_RLE => { + return ERROR(ZstdErrorCode::Generic); /* not yet handled */ + } + BT_END => { + /* should never happen (filtered at phase 1) */ + 0 + } + _ => { + return ERROR(ZstdErrorCode::Generic); + } + }; + (*ctx).phase = 1; + (*ctx).expected = ZSTD_BLOCK_HEADER_SIZE; + if ERR_isError(r_size) { + return r_size; + } + (*ctx).previous_dst_end = (dst as usize + r_size) as *const u8; + r_size + } +} + +#[cfg(test)] +mod tests { + use super::*; + + /// 237-byte base text; the fixtures compress repetitions of it. + const SAMPLE: &str = "snowden is snowed in / he's now then in his snow den / when does the snow end?\ngoodbye little dog / you dug some holes in your day / they'll be hard to fill.\nwhen life shuts a door, / just open it. it's a door. / that is how doors work.\n"; + + /// `SAMPLE` repeated 3 times (711 bytes), compressed by a zstd binary + /// built from the v0.1.0 tag. Single compressed block (FSE + Huff0), + /// verified byte-identical against the pristine C decoder. + const FRAME_ENTROPY: &[u8] = &[ + 0xFD, 0x2F, 0xB5, 0x1E, 0x00, 0x00, 0xB0, 0x00, 0x00, 0x93, 0x00, 0xD6, 0x19, 0x80, 0x87, + 0xB1, 0x00, 0xC0, 0x73, 0xC5, 0x8A, 0xA5, 0x6C, 0x6F, 0x4B, 0xF2, 0x9F, 0x94, 0xC4, 0x2B, + 0xE4, 0x6B, 0x2C, 0x96, 0xAE, 0x5F, 0xC8, 0x9C, 0x1F, 0x00, 0x1C, 0x00, 0x1B, 0x00, 0x43, + 0x31, 0x70, 0xE4, 0xC9, 0xA3, 0x46, 0xD9, 0xAD, 0xFD, 0x78, 0x37, 0x66, 0xA6, 0x4D, 0x15, + 0xCA, 0x33, 0xF5, 0xA7, 0x31, 0x83, 0x02, 0x96, 0x7E, 0xD0, 0x5E, 0xAC, 0xE9, 0x48, 0x03, + 0xC7, 0xEF, 0x44, 0x81, 0x0B, 0x00, 0x90, 0xEA, 0x55, 0x41, 0xD8, 0x4E, 0x36, 0x10, 0xAC, + 0x95, 0x92, 0x42, 0x5D, 0x92, 0xF4, 0x64, 0x7F, 0x96, 0x44, 0x59, 0x0B, 0x03, 0x4A, 0xF6, + 0x16, 0x9F, 0xC8, 0xB9, 0x11, 0x70, 0xB8, 0x35, 0x06, 0xC4, 0x26, 0xC7, 0x6A, 0x89, 0xE4, + 0x6F, 0x65, 0xC0, 0x9B, 0x55, 0x08, 0xEB, 0xE8, 0x37, 0x66, 0x67, 0x9E, 0x7D, 0x57, 0xA0, + 0x25, 0x0D, 0xA4, 0x3E, 0x26, 0x8F, 0x32, 0xF6, 0xC9, 0x49, 0x50, 0x40, 0x0A, 0xED, 0x34, + 0x94, 0x15, 0x5E, 0xE3, 0x1B, 0xD6, 0x27, 0x05, 0x00, 0x54, 0x05, 0x41, 0xFF, 0xD6, 0x01, + 0x00, 0x80, 0x36, 0x00, 0xFE, 0x8D, 0x38, 0x42, 0x51, 0x7E, 0x40, 0x38, 0xD5, 0x60, 0x46, + 0x03, 0x90, 0x25, 0xC0, 0x00, 0x00, + ]; + + /// 48 random bytes compressed by v0.1.0: a raw (uncompressed) block. + const FRAME_RAW: &[u8] = &[ + 0xFD, 0x2F, 0xB5, 0x1E, 0x40, 0x00, 0x30, 0x77, 0xE9, 0x9A, 0x70, 0x2F, 0x77, 0x16, 0x9A, + 0x92, 0xD4, 0xEE, 0x72, 0xFD, 0xDD, 0x0F, 0x39, 0x33, 0x8B, 0x8B, 0x3C, 0x6A, 0x91, 0xB2, + 0x2B, 0x3A, 0xF0, 0x0E, 0xA6, 0x4C, 0x51, 0xA0, 0xC9, 0x5F, 0x69, 0x1A, 0xCE, 0x93, 0x5C, + 0x7F, 0x43, 0x0C, 0xD9, 0x25, 0xBC, 0x91, 0xDD, 0x6E, 0xD7, 0xC0, 0x00, 0x00, + ]; + + const RAW_PAYLOAD: &[u8] = &[ + 0x77, 0xE9, 0x9A, 0x70, 0x2F, 0x77, 0x16, 0x9A, 0x92, 0xD4, 0xEE, 0x72, 0xFD, 0xDD, 0x0F, + 0x39, 0x33, 0x8B, 0x8B, 0x3C, 0x6A, 0x91, 0xB2, 0x2B, 0x3A, 0xF0, 0x0E, 0xA6, 0x4C, 0x51, + 0xA0, 0xC9, 0x5F, 0x69, 0x1A, 0xCE, 0x93, 0x5C, 0x7F, 0x43, 0x0C, 0xD9, 0x25, 0xBC, 0x91, + 0xDD, 0x6E, 0xD7, + ]; + + /// `SAMPLE` repeated 1800 times (426600 bytes) compressed by v0.1.0: + /// four data blocks, so it exercises multi-block frames and repeated + /// offsets. + const FRAME_MULTI_BLOCK: &[u8] = &[ + 0xFD, 0x2F, 0xB5, 0x1E, 0x00, 0x00, 0xB0, 0x00, 0x00, 0x93, 0x00, 0xD6, 0x19, 0x80, 0x87, + 0xB1, 0x00, 0xC0, 0x73, 0xC5, 0x8A, 0xA5, 0x6C, 0x6F, 0x4B, 0xF2, 0x9F, 0x94, 0xC4, 0x2B, + 0xE4, 0x6B, 0x2C, 0x96, 0xAE, 0x5F, 0xC8, 0x9C, 0x1F, 0x00, 0x1C, 0x00, 0x1B, 0x00, 0x43, + 0x31, 0x70, 0xE4, 0xC9, 0xA3, 0x46, 0xD9, 0xAD, 0xFD, 0x78, 0x37, 0x66, 0xA6, 0x4D, 0x15, + 0xCA, 0x33, 0xF5, 0xA7, 0x31, 0x83, 0x02, 0x96, 0x7E, 0xD0, 0x5E, 0xAC, 0xE9, 0x48, 0x03, + 0xC7, 0xEF, 0x44, 0x81, 0x0B, 0x00, 0x90, 0xEA, 0x55, 0x41, 0xD8, 0x4E, 0x36, 0x10, 0xAC, + 0x95, 0x92, 0x42, 0x5D, 0x92, 0xF4, 0x64, 0x7F, 0x96, 0x44, 0x59, 0x0B, 0x03, 0x4A, 0xF6, + 0x16, 0x9F, 0xC8, 0xB9, 0x11, 0x70, 0xB8, 0x35, 0x06, 0xC4, 0x26, 0xC7, 0x6A, 0x89, 0xE4, + 0x6F, 0x65, 0xC0, 0x9B, 0x55, 0x08, 0xEB, 0xE8, 0x37, 0x66, 0x67, 0x9E, 0x7D, 0x57, 0xA0, + 0x25, 0x0D, 0xA4, 0x3E, 0x26, 0x8F, 0x32, 0xF6, 0xC9, 0x49, 0x50, 0x40, 0x0A, 0xED, 0x34, + 0x94, 0x15, 0x5E, 0xE3, 0x1B, 0xD6, 0x27, 0x05, 0x00, 0x54, 0x05, 0x41, 0xFF, 0x0F, 0xFF, + 0x01, 0x80, 0x36, 0x00, 0xFE, 0x8D, 0x38, 0x42, 0x51, 0x7E, 0x40, 0x38, 0xD5, 0x60, 0x46, + 0x03, 0x90, 0x25, 0x00, 0x00, 0x12, 0x40, 0x00, 0x00, 0x01, 0x00, 0x54, 0x04, 0xFF, 0xFC, + 0xFF, 0x01, 0x80, 0xFA, 0x7F, 0x00, 0xFC, 0x23, 0x10, 0x00, 0x00, 0x12, 0x40, 0x00, 0x00, + 0x01, 0x00, 0x54, 0x04, 0xFF, 0xFC, 0xFF, 0x01, 0x00, 0xF5, 0xFF, 0x00, 0xF8, 0x4B, 0x20, + 0x00, 0x00, 0x12, 0x40, 0x00, 0x00, 0x01, 0x00, 0x54, 0x04, 0xFF, 0x64, 0x82, 0x00, 0x80, + 0xEF, 0xFF, 0x00, 0xF0, 0x9F, 0x40, 0xC0, 0x00, 0x00, + ]; + + fn decompress(frame: &[u8], capacity: usize) -> Result, usize> { + let mut out = vec![0u8; capacity]; + let code = unsafe { + ZSTDv01_decompress( + out.as_mut_ptr() as *mut c_void, + capacity, + frame.as_ptr() as *const c_void, + frame.len(), + ) + }; + if ZSTDv01_isError(code) != 0 { + return Err(code); + } + out.truncate(code); + Ok(out) + } + + fn frame_size_info(frame: &[u8]) -> (usize, u64) { + let mut c_size = 0usize; + let mut d_bound = 0u64; + unsafe { + ZSTDv01_findFrameSizeInfoLegacy( + frame.as_ptr() as *const c_void, + frame.len(), + &mut c_size, + &mut d_bound, + ); + } + (c_size, d_bound) + } + + #[test] + fn decodes_entropy_frame_byte_identically() { + let expected = SAMPLE.repeat(3).into_bytes(); + let out = decompress(FRAME_ENTROPY, expected.len()).unwrap(); + assert_eq!(out, expected); + } + + #[test] + fn decodes_raw_block_frame_byte_identically() { + let out = decompress(FRAME_RAW, RAW_PAYLOAD.len()).unwrap(); + assert_eq!(out, RAW_PAYLOAD); + } + + #[test] + fn decodes_multi_block_frame_byte_identically() { + let expected = SAMPLE.repeat(1800).into_bytes(); + assert_eq!(expected.len(), 426600); + let out = decompress(FRAME_MULTI_BLOCK, expected.len()).unwrap(); + assert_eq!(out, expected); + } + + #[test] + fn reports_frame_size_info_like_c() { + /* Values verified against the pristine C implementation. */ + assert_eq!( + frame_size_info(FRAME_ENTROPY), + (FRAME_ENTROPY.len(), 131072) + ); + assert_eq!(frame_size_info(FRAME_RAW), (FRAME_RAW.len(), 131072)); + assert_eq!( + frame_size_info(FRAME_MULTI_BLOCK), + (FRAME_MULTI_BLOCK.len(), 524288) + ); + } + + #[test] + fn rejects_bad_magic_with_prefix_unknown() { + let mut frame = FRAME_ENTROPY.to_vec(); + frame[0] ^= 0x55; + assert_eq!( + decompress(&frame, 1024).unwrap_err(), + ERROR(ZstdErrorCode::PrefixUnknown) + ); + let (c_size, d_bound) = frame_size_info(&frame); + assert_eq!(c_size, ERROR(ZstdErrorCode::PrefixUnknown)); + assert_eq!(d_bound, ZSTD_CONTENTSIZE_ERROR); + } + + #[test] + fn rejects_truncated_frames_with_src_size_wrong() { + for frame in [FRAME_ENTROPY, FRAME_RAW, FRAME_MULTI_BLOCK] { + let truncated = &frame[..frame.len() - 1]; + assert_eq!( + decompress(truncated, 1 << 20).unwrap_err(), + ERROR(ZstdErrorCode::SrcSizeWrong) + ); + assert_eq!( + decompress(&frame[..5], 1 << 20).unwrap_err(), + ERROR(ZstdErrorCode::SrcSizeWrong) + ); + } + } + + #[test] + fn rejects_small_destination_with_dst_size_too_small() { + /* Error codes verified against the pristine C implementation. */ + let expected_len = SAMPLE.len() * 3; + assert_eq!( + decompress(FRAME_ENTROPY, expected_len - 1).unwrap_err(), + ERROR(ZstdErrorCode::DstSizeTooSmall) + ); + assert_eq!( + decompress(FRAME_ENTROPY, 0).unwrap_err(), + ERROR(ZstdErrorCode::DstSizeTooSmall) + ); + assert_eq!( + decompress(FRAME_RAW, RAW_PAYLOAD.len() - 1).unwrap_err(), + ERROR(ZstdErrorCode::DstSizeTooSmall) + ); + } + + #[test] + fn streaming_api_decodes_the_frame() { + let expected = SAMPLE.repeat(3).into_bytes(); + let mut out = vec![0u8; expected.len()]; + let mut in_pos = 0usize; + let mut out_pos = 0usize; + unsafe { + let dctx = ZSTDv01_createDCtx(); + assert!(!dctx.is_null()); + loop { + let needed = ZSTDv01_nextSrcSizeToDecompress(dctx); + if needed == 0 { + break; + } + assert!(in_pos + needed <= FRAME_ENTROPY.len()); + let produced = ZSTDv01_decompressContinue( + dctx, + out.as_mut_ptr().add(out_pos) as *mut c_void, + out.len() - out_pos, + FRAME_ENTROPY.as_ptr().add(in_pos) as *const c_void, + needed, + ); + assert_eq!(ZSTDv01_isError(produced), 0); + in_pos += needed; + out_pos += produced; + } + assert_eq!(ZSTDv01_freeDCtx(dctx), 0); + } + assert_eq!(in_pos, FRAME_ENTROPY.len()); + assert_eq!(out_pos, expected.len()); + assert_eq!(out, expected); + } + + #[test] + fn streaming_context_reset_and_null_free() { + unsafe { + let dctx = ZSTDv01_createDCtx(); + assert_eq!(ZSTDv01_nextSrcSizeToDecompress(dctx), 4); + /* bad magic through the streaming entry point */ + let bad = [0u8; 4]; + assert_eq!( + ZSTDv01_decompressContinue( + dctx, + ptr::null_mut(), + 0, + bad.as_ptr() as *const c_void, + 4 + ), + ERROR(ZstdErrorCode::PrefixUnknown) + ); + /* wrong srcSize */ + assert_eq!( + ZSTDv01_decompressContinue( + dctx, + ptr::null_mut(), + 0, + bad.as_ptr() as *const c_void, + 3 + ), + ERROR(ZstdErrorCode::SrcSizeWrong) + ); + assert_eq!(ZSTDv01_resetDCtx(dctx), 0); + assert_eq!(ZSTDv01_nextSrcSizeToDecompress(dctx), 4); + assert_eq!(ZSTDv01_freeDCtx(dctx), 0); + assert_eq!(ZSTDv01_freeDCtx(ptr::null_mut()), 0); + } + } +}