From cd1e1829081ad9ab0af20d5c088a2a6d0871ddfc Mon Sep 17 00:00:00 2001 From: Tino Reichardt Date: Sat, 4 May 2019 22:40:27 +0200 Subject: [PATCH] Update lz4 to version 1.9.1 --- C/7zVersion.h | 4 +- C/lz4/README.md | 67 +++- C/lz4/lz4.c | 882 ++++++++++++++++++++++++++++++++--------------- C/lz4/lz4.h | 373 +++++++++++--------- C/lz4/lz4frame.c | 430 +++++++++++++---------- C/lz4/lz4frame.h | 147 +++++--- C/lz4/lz4hc.c | 360 +++++++++++-------- C/lz4/lz4hc.h | 246 ++++++++----- README.md | 6 +- 9 files changed, 1605 insertions(+), 910 deletions(-) diff --git a/C/7zVersion.h b/C/7zVersion.h index 8a864fd2..0fcb3c52 100644 --- a/C/7zVersion.h +++ b/C/7zVersion.h @@ -1,7 +1,7 @@ #define MY_VER_MAJOR 19 #define MY_VER_MINOR 00 #define MY_VER_BUILD 0 -#define MY_VERSION_NUMBERS "19.00 ZS v1.4.0 R1" +#define MY_VERSION_NUMBERS "19.00 ZS v1.4.0 R2" #define MY_VERSION MY_VERSION_NUMBERS #ifdef MY_CPU_NAME @@ -10,7 +10,7 @@ #define MY_VERSION_CPU MY_VERSION #endif -#define MY_DATE "2019-04-26" +#define MY_DATE "2019-05-04" #undef MY_COPYRIGHT #undef MY_VERSION_COPYRIGHT_DATE #define MY_AUTHOR_NAME "Igor Pavlov, Tino Reichardt" diff --git a/C/lz4/README.md b/C/lz4/README.md index 7082fe3e..b753195c 100644 --- a/C/lz4/README.md +++ b/C/lz4/README.md @@ -7,8 +7,8 @@ not all of them are necessary. #### Minimal LZ4 build The minimum required is **`lz4.c`** and **`lz4.h`**, -which provides the fast compression and decompression algorithm. -They generate and decode data using [LZ4 block format]. +which provides the fast compression and decompression algorithms. +They generate and decode data using the [LZ4 block format]. #### High Compression variant @@ -16,13 +16,14 @@ They generate and decode data using [LZ4 block format]. For more compression ratio at the cost of compression speed, the High Compression variant called **lz4hc** is available. Add files **`lz4hc.c`** and **`lz4hc.h`**. -The variant still depends on regular `lib/lz4.*` source files. +This variant also compresses data using the [LZ4 block format], +and depends on regular `lib/lz4.*` source files. -#### Frame variant, for interoperability +#### Frame support, for interoperability In order to produce compressed data compatible with `lz4` command line utility, -it's necessary to encode lz4-compressed blocks using the [official interoperable frame format]. +it's necessary to use the [official interoperable frame format]. This format is generated and decoded automatically by the **lz4frame** library. Its public API is described in `lib/lz4frame.h`. In order to work properly, lz4frame needs all other modules present in `/lib`, @@ -32,15 +33,63 @@ So it's necessary to include all `*.c` and `*.h` files present in `/lib`. #### Advanced / Experimental API -A complex API defined in `lz4frame_static.h` contains definitions -which are not guaranteed to remain stable in future versions. -As a consequence, it must be used with static linking ***only***. +Definitions which are not guaranteed to remain stable in future versions, +are protected behind macros, such as `LZ4_STATIC_LINKING_ONLY`. +As the name implies, these definitions can only be invoked +in the context of static linking ***only***. +Otherwise, dependent application may fail on API or ABI break in the future. +The associated symbols are also not present in dynamic library by default. +Should they be nonetheless needed, it's possible to force their publication +by using build macro `LZ4_PUBLISH_STATIC_FUNCTIONS`. + + +#### Build macros + +The following build macro can be selected at compilation time : + +- `LZ4_FAST_DEC_LOOP` : this triggers the optimized decompression loop. + This loops works great on x86/x64 cpus, and is automatically enabled on this platform. + It's possible to enable or disable it manually, by passing `LZ4_FAST_DEC_LOOP=1` or `0` to the preprocessor. + For example, with `gcc` : `-DLZ4_FAST_DEC_LOOP=1`, + and with `make` : `CPPFLAGS+=-DLZ4_FAST_DEC_LOOP=1 make lz4`. + +- `LZ4_DISTANCE_MAX` : control the maximum offset that the compressor will allow. + Set to 65535 by default, which is the maximum value supported by lz4 format. + Reducing maximum distance will reduce opportunities for LZ4 to find matches, + hence will produce worse the compression ratio. + However, a smaller max distance may allow compatibility with specific decoders using limited memory budget. + This build macro only influences the compressed output of the compressor. + +- `LZ4_DISABLE_DEPRECATE_WARNINGS` : invoking a deprecated function will make the compiler generate a warning. + This is meant to invite users to update their source code. + Should this be a problem, it's generally possible to make the compiler ignore these warnings, + for example with `-Wno-deprecated-declarations` on `gcc`, + or `_CRT_SECURE_NO_WARNINGS` for Visual Studio. + Another method is to define `LZ4_DISABLE_DEPRECATE_WARNINGS` + before including the LZ4 header files. + + +#### Amalgamation + +lz4 source code can be amalgamated into a single file. +One can combine all source code into `lz4_all.c` by using following command: +``` +cat lz4.c > lz4_all.c +cat lz4hc.c >> lz4_all.c +cat lz4frame.c >> lz4_all.c +``` +(`cat` file order is important) then compile `lz4_all.c`. +All `*.h` files present in `/lib` remain necessary to compile `lz4_all.c`. #### Windows : using MinGW+MSYS to create DLL DLL can be created using MinGW+MSYS with the `make liblz4` command. This command creates `dll\liblz4.dll` and the import library `dll\liblz4.lib`. +To override the `dlltool` command when cross-compiling on Linux, just set the `DLLTOOL` variable. Example of cross compilation on Linux with mingw-w64 64 bits: +``` +make BUILD_STATIC=no CC=x86_64-w64-mingw32-gcc DLLTOOL=x86_64-w64-mingw32-dlltool OS=Windows_NT +``` The import library is only required with Visual C++. The header files `lz4.h`, `lz4hc.h`, `lz4frame.h` and the dynamic library `dll\liblz4.dll` are required to compile a project using gcc/MinGW. @@ -48,7 +97,7 @@ The dynamic library has to be added to linking options. It means that if a project that uses LZ4 consists of a single `test-dll.c` file it should be linked with `dll\liblz4.dll`. For example: ``` - gcc $(CFLAGS) -Iinclude/ test-dll.c -o test-dll dll\liblz4.dll + $(CC) $(CFLAGS) -Iinclude/ test-dll.c -o test-dll dll\liblz4.dll ``` The compiled executable will require LZ4 DLL which is available at `dll\liblz4.dll`. diff --git a/C/lz4/lz4.c b/C/lz4/lz4.c index 4046102e..e614c457 100644 --- a/C/lz4/lz4.c +++ b/C/lz4/lz4.c @@ -32,7 +32,6 @@ - LZ4 source repository : https://github.com/lz4/lz4 */ - /*-************************************ * Tuning parameters **************************************/ @@ -91,8 +90,22 @@ /*-************************************ * Dependency **************************************/ +/* + * LZ4_SRC_INCLUDED: + * Amalgamation flag, whether lz4.c is included + */ +#ifndef LZ4_SRC_INCLUDED +# define LZ4_SRC_INCLUDED 1 +#endif + +#ifndef LZ4_STATIC_LINKING_ONLY #define LZ4_STATIC_LINKING_ONLY +#endif + +#ifndef LZ4_DISABLE_DEPRECATE_WARNINGS #define LZ4_DISABLE_DEPRECATE_WARNINGS /* due to LZ4_decompress_safe_withPrefix64k */ +#endif + #include "lz4.h" /* see also "memory routines" below */ @@ -123,7 +136,7 @@ #endif /* LZ4_FORCE_INLINE */ /* LZ4_FORCE_O2_GCC_PPC64LE and LZ4_FORCE_O2_INLINE_GCC_PPC64LE - * Gcc on ppc64le generates an unrolled SIMDized loop for LZ4_wildCopy, + * gcc on ppc64le generates an unrolled SIMDized loop for LZ4_wildCopy8, * together with a simple 8-byte copy loop as a fall-back path. * However, this optimization hurts the decompression speed by >30%, * because the execution does not go to the optimized loop @@ -131,12 +144,12 @@ * before going to the fall-back path become useless overhead. * This optimization happens only with the -O3 flag, and -O2 generates * a simple 8-byte copy loop. - * With gcc on ppc64le, all of the LZ4_decompress_* and LZ4_wildCopy + * With gcc on ppc64le, all of the LZ4_decompress_* and LZ4_wildCopy8 * functions are annotated with __attribute__((optimize("O2"))), - * and also LZ4_wildCopy is forcibly inlined, so that the O2 attribute - * of LZ4_wildCopy does not affect the compression speed. + * and also LZ4_wildCopy8 is forcibly inlined, so that the O2 attribute + * of LZ4_wildCopy8 does not affect the compression speed. */ -#if defined(__PPC64__) && defined(__LITTLE_ENDIAN__) && defined(__GNUC__) +#if defined(__PPC64__) && defined(__LITTLE_ENDIAN__) && defined(__GNUC__) && !defined(__clang__) # define LZ4_FORCE_O2_GCC_PPC64LE __attribute__((optimize("O2"))) # define LZ4_FORCE_O2_INLINE_GCC_PPC64LE __attribute__((optimize("O2"))) LZ4_FORCE_INLINE #else @@ -170,7 +183,7 @@ /*-************************************ -* Basic Types +* Types **************************************/ #if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) # include @@ -195,6 +208,13 @@ typedef size_t reg_t; /* 32-bits in x32 mode */ #endif +typedef enum { + notLimited = 0, + limitedOutput = 1, + fillOutput = 2 +} limitedOutput_directive; + + /*-************************************ * Reading and writing into memory **************************************/ @@ -228,7 +248,7 @@ static reg_t LZ4_read_ARCH(const void* ptr) { return ((const unalign*)ptr)->uArc static void LZ4_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; } static void LZ4_write32(void* memPtr, U32 value) { ((unalign*)memPtr)->u32 = value; } -#else /* safe and portable access through memcpy() */ +#else /* safe and portable access using memcpy() */ static U16 LZ4_read16(const void* memPtr) { @@ -281,7 +301,7 @@ static void LZ4_writeLE16(void* memPtr, U16 value) /* customized variant of memcpy, which can overwrite up to 8 bytes beyond dstEnd */ LZ4_FORCE_O2_INLINE_GCC_PPC64LE -void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd) +void LZ4_wildCopy8(void* dstPtr, const void* srcPtr, void* dstEnd) { BYTE* d = (BYTE*)dstPtr; const BYTE* s = (const BYTE*)srcPtr; @@ -290,6 +310,86 @@ void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd) do { memcpy(d,s,8); d+=8; s+=8; } while (d= 16. */ +LZ4_FORCE_O2_INLINE_GCC_PPC64LE void +LZ4_wildCopy32(void* dstPtr, const void* srcPtr, void* dstEnd) +{ + BYTE* d = (BYTE*)dstPtr; + const BYTE* s = (const BYTE*)srcPtr; + BYTE* const e = (BYTE*)dstEnd; + + do { memcpy(d,s,16); memcpy(d+16,s+16,16); d+=32; s+=32; } while (d 65535) /* max supported by LZ4 format */ +# error "LZ4_DISTANCE_MAX is too big : must be <= 65535" +#endif #define ML_BITS 4 #define ML_MASK ((1U< compression ru /*-************************************ * Local Structures and types **************************************/ -typedef enum { notLimited = 0, limitedOutput = 1, fillOutput = 2 } limitedOutput_directive; typedef enum { clearedTable = 0, byPtr, byU32, byU16 } tableType_t; /** @@ -522,13 +627,14 @@ static U32 LZ4_hash4(U32 sequence, tableType_t const tableType) static U32 LZ4_hash5(U64 sequence, tableType_t const tableType) { - static const U64 prime5bytes = 889523592379ULL; - static const U64 prime8bytes = 11400714785074694791ULL; const U32 hashLog = (tableType == byU16) ? LZ4_HASHLOG+1 : LZ4_HASHLOG; - if (LZ4_isLittleEndian()) + if (LZ4_isLittleEndian()) { + const U64 prime5bytes = 889523592379ULL; return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog)); - else + } else { + const U64 prime8bytes = 11400714785074694791ULL; return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog)); + } } LZ4_FORCE_INLINE U32 LZ4_hashPosition(const void* const p, tableType_t const tableType) @@ -609,6 +715,15 @@ LZ4_FORCE_INLINE void LZ4_prepareTable( LZ4_stream_t_internal* const cctx, const int inputSize, const tableType_t tableType) { + /* If compression failed during the previous step, then the context + * is marked as dirty, therefore, it has to be fully reset. + */ + if (cctx->dirty) { + DEBUGLOG(5, "LZ4_prepareTable: Full reset for %p", cctx); + MEM_INIT(cctx, 0, sizeof(LZ4_stream_t_internal)); + return; + } + /* If the table hasn't been used, it's guaranteed to be zeroed out, and is * therefore safe to use no matter what mode we're in. Otherwise, we figure * out if it's safe to leave as is or whether it needs to be reset. @@ -629,7 +744,7 @@ LZ4_FORCE_INLINE void LZ4_prepareTable( } } - /* Adding a gap, so all previous entries are > MAX_DISTANCE back, is faster + /* Adding a gap, so all previous entries are > LZ4_DISTANCE_MAX back, is faster * than compressing without a gap. However, compressing with * currentOffset == 0 is faster still, so we preserve that case. */ @@ -651,14 +766,15 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( const char* const source, char* const dest, const int inputSize, - int *inputConsumed, /* only written when outputLimited == fillOutput */ + int *inputConsumed, /* only written when outputDirective == fillOutput */ const int maxOutputSize, - const limitedOutput_directive outputLimited, + const limitedOutput_directive outputDirective, const tableType_t tableType, const dict_directive dictDirective, const dictIssue_directive dictIssue, - const U32 acceleration) + const int acceleration) { + int result; const BYTE* ip = (const BYTE*) source; U32 const startIndex = cctx->currentOffset; @@ -693,9 +809,10 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( U32 forwardH; DEBUGLOG(5, "LZ4_compress_generic: srcSize=%i, tableType=%u", inputSize, tableType); - /* Init conditions */ - if (outputLimited == fillOutput && maxOutputSize < 1) return 0; /* Impossible to store anything */ - if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported inputSize, too large (or negative) */ + /* If init conditions are not met, we don't have to mark stream + * as having dirty context, since no action was taken yet */ + if (outputDirective == fillOutput && maxOutputSize < 1) return 0; /* Impossible to store anything */ + if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported inputSize, too large (or negative) */ if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */ if (tableType==byPtr) assert(dictDirective==noDict); /* only supported use case with byPtr */ assert(acceleration >= 1); @@ -728,8 +845,8 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( /* Find a match */ if (tableType == byPtr) { const BYTE* forwardIp = ip; - unsigned step = 1; - unsigned searchMatchNb = acceleration << LZ4_skipTrigger; + int step = 1; + int searchMatchNb = acceleration << LZ4_skipTrigger; do { U32 const h = forwardH; ip = forwardIp; @@ -743,14 +860,14 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( forwardH = LZ4_hashPosition(forwardIp, tableType); LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType, base); - } while ( (match+MAX_DISTANCE < ip) + } while ( (match+LZ4_DISTANCE_MAX < ip) || (LZ4_read32(match) != LZ4_read32(ip)) ); } else { /* byU32, byU16 */ const BYTE* forwardIp = ip; - unsigned step = 1; - unsigned searchMatchNb = acceleration << LZ4_skipTrigger; + int step = 1; + int searchMatchNb = acceleration << LZ4_skipTrigger; do { U32 const h = forwardH; U32 const current = (U32)(forwardIp - base); @@ -794,8 +911,8 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( if ((dictIssue == dictSmall) && (matchIndex < prefixIdxLimit)) continue; /* match outside of valid area */ assert(matchIndex < current); - if ((tableType != byU16) && (matchIndex+MAX_DISTANCE < current)) continue; /* too far */ - if (tableType == byU16) assert((current - matchIndex) <= MAX_DISTANCE); /* too_far presumed impossible with byU16 */ + if ((tableType != byU16) && (matchIndex+LZ4_DISTANCE_MAX < current)) continue; /* too far */ + if (tableType == byU16) assert((current - matchIndex) <= LZ4_DISTANCE_MAX); /* too_far presumed impossible with byU16 */ if (LZ4_read32(match) == LZ4_read32(ip)) { if (maybe_extMem) offset = current - matchIndex; @@ -811,16 +928,17 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( /* Encode Literals */ { unsigned const litLength = (unsigned)(ip - anchor); token = op++; - if ((outputLimited == limitedOutput) && /* Check output buffer overflow */ - (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit))) - return 0; - if ((outputLimited == fillOutput) && + if ((outputDirective == limitedOutput) && /* Check output buffer overflow */ + (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)) ) + return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */ + + if ((outputDirective == fillOutput) && (unlikely(op + (litLength+240)/255 /* litlen */ + litLength /* literals */ + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit))) { op--; goto _last_literals; } if (litLength >= RUN_MASK) { - int len = (int)litLength-RUN_MASK; + int len = (int)(litLength - RUN_MASK); *token = (RUN_MASK<= 255 ; len-=255) *op++ = 255; *op++ = (BYTE)len; @@ -828,7 +946,7 @@ LZ4_FORCE_INLINE int LZ4_compress_generic( else *token = (BYTE)(litLength< olimit)) { /* the match was too close to the end, rewind and go to last literals */ op = token; @@ -853,11 +971,11 @@ _next_match: /* Encode Offset */ if (maybe_extMem) { /* static test */ DEBUGLOG(6, " with offset=%u (ext if > %i)", offset, (int)(ip - (const BYTE*)source)); - assert(offset <= MAX_DISTANCE && offset > 0); + assert(offset <= LZ4_DISTANCE_MAX && offset > 0); LZ4_writeLE16(op, (U16)offset); op+=2; } else { DEBUGLOG(6, " with offset=%u (same segment)", (U32)(ip - match)); - assert(ip-match <= MAX_DISTANCE); + assert(ip-match <= LZ4_DISTANCE_MAX); LZ4_writeLE16(op, (U16)(ip - match)); op+=2; } @@ -870,7 +988,7 @@ _next_match: assert(dictEnd > match); if (limit > matchlimit) limit = matchlimit; matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, limit); - ip += MINMATCH + matchCode; + ip += (size_t)matchCode + MINMATCH; if (ip==limit) { unsigned const more = LZ4_count(limit, (const BYTE*)source, matchlimit); matchCode += more; @@ -879,19 +997,20 @@ _next_match: DEBUGLOG(6, " with matchLength=%u starting in extDict", matchCode+MINMATCH); } else { matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit); - ip += MINMATCH + matchCode; + ip += (size_t)matchCode + MINMATCH; DEBUGLOG(6, " with matchLength=%u", matchCode+MINMATCH); } - if ((outputLimited) && /* Check output buffer overflow */ + if ((outputDirective) && /* Check output buffer overflow */ (unlikely(op + (1 + LASTLITERALS) + (matchCode>>8) > olimit)) ) { - if (outputLimited == limitedOutput) - return 0; - if (outputLimited == fillOutput) { + if (outputDirective == fillOutput) { /* Match description too long : reduce it */ U32 newMatchCode = 15 /* in token */ - 1 /* to avoid needing a zero byte */ + ((U32)(olimit - op) - 2 - 1 - LASTLITERALS) * 255; ip -= matchCode - newMatchCode; matchCode = newMatchCode; + } else { + assert(outputDirective == limitedOutput); + return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */ } } if (matchCode >= ML_MASK) { @@ -922,7 +1041,7 @@ _next_match: match = LZ4_getPosition(ip, cctx->hashTable, tableType, base); LZ4_putPosition(ip, cctx->hashTable, tableType, base); - if ( (match+MAX_DISTANCE >= ip) + if ( (match+LZ4_DISTANCE_MAX >= ip) && (LZ4_read32(match) == LZ4_read32(ip)) ) { token=op++; *token=0; goto _next_match; } @@ -957,7 +1076,7 @@ _next_match: LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType); assert(matchIndex < current); if ( ((dictIssue==dictSmall) ? (matchIndex >= prefixIdxLimit) : 1) - && ((tableType==byU16) ? 1 : (matchIndex+MAX_DISTANCE >= current)) + && ((tableType==byU16) ? 1 : (matchIndex+LZ4_DISTANCE_MAX >= current)) && (LZ4_read32(match) == LZ4_read32(ip)) ) { token=op++; *token=0; @@ -976,15 +1095,17 @@ _next_match: _last_literals: /* Encode Last Literals */ { size_t lastRun = (size_t)(iend - anchor); - if ( (outputLimited) && /* Check output buffer overflow */ + if ( (outputDirective) && /* Check output buffer overflow */ (op + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > olimit)) { - if (outputLimited == fillOutput) { + if (outputDirective == fillOutput) { /* adapt lastRun to fill 'dst' */ - lastRun = (olimit-op) - 1; + assert(olimit >= op); + lastRun = (size_t)(olimit-op) - 1; lastRun -= (lastRun+240)/255; + } else { + assert(outputDirective == limitedOutput); + return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */ } - if (outputLimited == limitedOutput) - return 0; } if (lastRun >= RUN_MASK) { size_t accumulator = lastRun - RUN_MASK; @@ -999,31 +1120,33 @@ _last_literals: op += lastRun; } - if (outputLimited == fillOutput) { + if (outputDirective == fillOutput) { *inputConsumed = (int) (((const char*)ip)-source); } DEBUGLOG(5, "LZ4_compress_generic: compressed %i bytes into %i bytes", inputSize, (int)(((char*)op) - dest)); - return (int)(((char*)op) - dest); + result = (int)(((char*)op) - dest); + assert(result > 0); + return result; } int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration) { - LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)state)->internal_donotuse; + LZ4_stream_t_internal* const ctx = & LZ4_initStream(state, sizeof(LZ4_stream_t)) -> internal_donotuse; + assert(ctx != NULL); if (acceleration < 1) acceleration = ACCELERATION_DEFAULT; - LZ4_resetStream((LZ4_stream_t*)state); if (maxOutputSize >= LZ4_compressBound(inputSize)) { if (inputSize < LZ4_64Klimit) { return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, byU16, noDict, noDictIssue, acceleration); } else { - const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > MAX_DISTANCE)) ? byPtr : byU32; + const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > LZ4_DISTANCE_MAX)) ? byPtr : byU32; return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration); } } else { if (inputSize < LZ4_64Klimit) {; return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration); } else { - const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > MAX_DISTANCE)) ? byPtr : byU32; + const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > LZ4_DISTANCE_MAX)) ? byPtr : byU32; return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, noDict, noDictIssue, acceleration); } } @@ -1053,7 +1176,7 @@ int LZ4_compress_fast_extState_fastReset(void* state, const char* src, char* dst return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration); } } else { - const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32; + const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32; LZ4_prepareTable(ctx, srcSize, tableType); return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration); } @@ -1067,7 +1190,7 @@ int LZ4_compress_fast_extState_fastReset(void* state, const char* src, char* dst return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration); } } else { - const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32; + const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32; LZ4_prepareTable(ctx, srcSize, tableType); return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration); } @@ -1094,23 +1217,25 @@ int LZ4_compress_fast(const char* source, char* dest, int inputSize, int maxOutp } -int LZ4_compress_default(const char* source, char* dest, int inputSize, int maxOutputSize) +int LZ4_compress_default(const char* src, char* dst, int srcSize, int maxOutputSize) { - return LZ4_compress_fast(source, dest, inputSize, maxOutputSize, 1); + return LZ4_compress_fast(src, dst, srcSize, maxOutputSize, 1); } /* hidden debug function */ /* strangely enough, gcc generates faster code when this function is uncommented, even if unused */ -int LZ4_compress_fast_force(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration) +int LZ4_compress_fast_force(const char* src, char* dst, int srcSize, int dstCapacity, int acceleration) { LZ4_stream_t ctx; - LZ4_resetStream(&ctx); + LZ4_initStream(&ctx, sizeof(ctx)); - if (inputSize < LZ4_64Klimit) - return LZ4_compress_generic(&ctx.internal_donotuse, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration); - else - return LZ4_compress_generic(&ctx.internal_donotuse, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, sizeof(void*)==8 ? byU32 : byPtr, noDict, noDictIssue, acceleration); + if (srcSize < LZ4_64Klimit) { + return LZ4_compress_generic(&ctx.internal_donotuse, src, dst, srcSize, NULL, dstCapacity, limitedOutput, byU16, noDict, noDictIssue, acceleration); + } else { + tableType_t const addrMode = (sizeof(void*) > 4) ? byU32 : byPtr; + return LZ4_compress_generic(&ctx.internal_donotuse, src, dst, srcSize, NULL, dstCapacity, limitedOutput, addrMode, noDict, noDictIssue, acceleration); + } } @@ -1119,7 +1244,8 @@ int LZ4_compress_fast_force(const char* source, char* dest, int inputSize, int m * _continue() call without resetting it. */ static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize) { - LZ4_resetStream(state); + void* const s = LZ4_initStream(state, sizeof (*state)); + assert(s != NULL); (void)s; if (targetDstSize >= LZ4_compressBound(*srcSizePtr)) { /* compression success is guaranteed */ return LZ4_compress_fast_extState(state, src, dst, *srcSizePtr, targetDstSize, 1); @@ -1127,8 +1253,8 @@ static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src, if (*srcSizePtr < LZ4_64Klimit) { return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, byU16, noDict, noDictIssue, 1); } else { - tableType_t const tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32; - return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, tableType, noDict, noDictIssue, 1); + tableType_t const addrMode = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32; + return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, addrMode, noDict, noDictIssue, 1); } } } @@ -1159,14 +1285,40 @@ int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targe LZ4_stream_t* LZ4_createStream(void) { - LZ4_stream_t* lz4s = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t)); + LZ4_stream_t* const lz4s = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t)); LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal)); /* A compilation error here means LZ4_STREAMSIZE is not large enough */ DEBUGLOG(4, "LZ4_createStream %p", lz4s); if (lz4s == NULL) return NULL; - LZ4_resetStream(lz4s); + LZ4_initStream(lz4s, sizeof(*lz4s)); return lz4s; } +#ifndef _MSC_VER /* for some reason, Visual fails the aligment test on 32-bit x86 : + it reports an aligment of 8-bytes, + while actually aligning LZ4_stream_t on 4 bytes. */ +static size_t LZ4_stream_t_alignment(void) +{ + struct { char c; LZ4_stream_t t; } t_a; + return sizeof(t_a) - sizeof(t_a.t); +} +#endif + +LZ4_stream_t* LZ4_initStream (void* buffer, size_t size) +{ + DEBUGLOG(5, "LZ4_initStream"); + if (buffer == NULL) return NULL; + if (size < sizeof(LZ4_stream_t)) return NULL; +#ifndef _MSC_VER /* for some reason, Visual fails the aligment test on 32-bit x86 : + it reports an aligment of 8-bytes, + while actually aligning LZ4_stream_t on 4 bytes. */ + if (((size_t)buffer) & (LZ4_stream_t_alignment() - 1)) return NULL; /* alignment check */ +#endif + MEM_INIT(buffer, 0, sizeof(LZ4_stream_t)); + return (LZ4_stream_t*)buffer; +} + +/* resetStream is now deprecated, + * prefer initStream() which is more general */ void LZ4_resetStream (LZ4_stream_t* LZ4_stream) { DEBUGLOG(5, "LZ4_resetStream (ctx:%p)", LZ4_stream); @@ -1226,10 +1378,16 @@ int LZ4_loadDict (LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize) p+=3; } - return dict->dictSize; + return (int)dict->dictSize; } void LZ4_attach_dictionary(LZ4_stream_t *working_stream, const LZ4_stream_t *dictionary_stream) { + /* Calling LZ4_resetStream_fast() here makes sure that changes will not be + * erased by subsequent calls to LZ4_resetStream_fast() in case stream was + * marked as having dirty context, e.g. requiring full reset. + */ + LZ4_resetStream_fast(working_stream); + if (dictionary_stream != NULL) { /* If the current offset is zero, we will never look in the * external dictionary context, since there is no value a table @@ -1248,7 +1406,8 @@ void LZ4_attach_dictionary(LZ4_stream_t *working_stream, const LZ4_stream_t *dic static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, int nextSize) { - if (LZ4_dict->currentOffset + nextSize > 0x80000000) { /* potential ptrdiff_t overflow (32-bits mode) */ + assert(nextSize >= 0); + if (LZ4_dict->currentOffset + (unsigned)nextSize > 0x80000000) { /* potential ptrdiff_t overflow (32-bits mode) */ /* rescale hash table */ U32 const delta = LZ4_dict->currentOffset - 64 KB; const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize; @@ -1265,7 +1424,10 @@ static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, int nextSize) } -int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration) +int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, + const char* source, char* dest, + int inputSize, int maxOutputSize, + int acceleration) { const tableType_t tableType = byU32; LZ4_stream_t_internal* streamPtr = &LZ4_stream->internal_donotuse; @@ -1273,12 +1435,12 @@ int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, const char* source, ch DEBUGLOG(5, "LZ4_compress_fast_continue (inputSize=%i)", inputSize); - if (streamPtr->initCheck) return 0; /* Uninitialized structure detected */ + if (streamPtr->dirty) return 0; /* Uninitialized structure detected */ LZ4_renormDictT(streamPtr, inputSize); /* avoid index overflow */ if (acceleration < 1) acceleration = ACCELERATION_DEFAULT; /* invalidate tiny dictionaries */ - if ( (streamPtr->dictSize-1 < 4) /* intentional underflow */ + if ( (streamPtr->dictSize-1 < 4-1) /* intentional underflow */ && (dictEnd != (const BYTE*)source) ) { DEBUGLOG(5, "LZ4_compress_fast_continue: dictSize(%u) at addr:%p is too small", streamPtr->dictSize, streamPtr->dictionary); streamPtr->dictSize = 0; @@ -1371,7 +1533,7 @@ int LZ4_saveDict (LZ4_stream_t* LZ4_dict, char* safeBuffer, int dictSize) const BYTE* const previousDictEnd = dict->dictionary + dict->dictSize; if ((U32)dictSize > 64 KB) dictSize = 64 KB; /* useless to define a dictionary > 64 KB */ - if ((U32)dictSize > dict->dictSize) dictSize = dict->dictSize; + if ((U32)dictSize > dict->dictSize) dictSize = (int)dict->dictSize; memmove(safeBuffer, previousDictEnd - dictSize, dictSize); @@ -1393,6 +1555,37 @@ typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive; #undef MIN #define MIN(a,b) ( (a) < (b) ? (a) : (b) ) +/* Read the variable-length literal or match length. + * + * ip - pointer to use as input. + * lencheck - end ip. Return an error if ip advances >= lencheck. + * loop_check - check ip >= lencheck in body of loop. Returns loop_error if so. + * initial_check - check ip >= lencheck before start of loop. Returns initial_error if so. + * error (output) - error code. Should be set to 0 before call. + */ +typedef enum { loop_error = -2, initial_error = -1, ok = 0 } variable_length_error; +LZ4_FORCE_INLINE unsigned +read_variable_length(const BYTE**ip, const BYTE* lencheck, int loop_check, int initial_check, variable_length_error* error) +{ + unsigned length = 0; + unsigned s; + if (initial_check && unlikely((*ip) >= lencheck)) { /* overflow detection */ + *error = initial_error; + return length; + } + do { + s = **ip; + (*ip)++; + length += s; + if (loop_check && unlikely((*ip) >= lencheck)) { /* overflow detection */ + *error = loop_error; + return length; + } + } while (s==255); + + return length; +} + /*! LZ4_decompress_generic() : * This generic decompression function covers all use cases. * It shall be instantiated several times, using different sets of directives. @@ -1414,234 +1607,369 @@ LZ4_decompress_generic( const size_t dictSize /* note : = 0 if noDict */ ) { - const BYTE* ip = (const BYTE*) src; - const BYTE* const iend = ip + srcSize; + if (src == NULL) return -1; - BYTE* op = (BYTE*) dst; - BYTE* const oend = op + outputSize; - BYTE* cpy; + { const BYTE* ip = (const BYTE*) src; + const BYTE* const iend = ip + srcSize; - const BYTE* const dictEnd = (const BYTE*)dictStart + dictSize; - const unsigned inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4}; - const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3}; + BYTE* op = (BYTE*) dst; + BYTE* const oend = op + outputSize; + BYTE* cpy; - const int safeDecode = (endOnInput==endOnInputSize); - const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB))); + const BYTE* const dictEnd = (dictStart == NULL) ? NULL : dictStart + dictSize; - /* Set up the "end" pointers for the shortcut. */ - const BYTE* const shortiend = iend - (endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/; - const BYTE* const shortoend = oend - (endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/; + const int safeDecode = (endOnInput==endOnInputSize); + const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB))); - DEBUGLOG(5, "LZ4_decompress_generic (srcSize:%i, dstSize:%i)", srcSize, outputSize); - /* Special cases */ - assert(lowPrefix <= op); - assert(src != NULL); - if ((endOnInput) && (unlikely(outputSize==0))) return ((srcSize==1) && (*ip==0)) ? 0 : -1; /* Empty output buffer */ - if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0 ? 1 : -1); - if ((endOnInput) && unlikely(srcSize==0)) return -1; + /* Set up the "end" pointers for the shortcut. */ + const BYTE* const shortiend = iend - (endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/; + const BYTE* const shortoend = oend - (endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/; - /* Main Loop : decode sequences */ - while (1) { const BYTE* match; size_t offset; + unsigned token; + size_t length; - unsigned const token = *ip++; - size_t length = token >> ML_BITS; /* literal length */ - assert(!endOnInput || ip <= iend); /* ip < iend before the increment */ + DEBUGLOG(5, "LZ4_decompress_generic (srcSize:%i, dstSize:%i)", srcSize, outputSize); - /* A two-stage shortcut for the most common case: - * 1) If the literal length is 0..14, and there is enough space, - * enter the shortcut and copy 16 bytes on behalf of the literals - * (in the fast mode, only 8 bytes can be safely copied this way). - * 2) Further if the match length is 4..18, copy 18 bytes in a similar - * manner; but we ensure that there's enough space in the output for - * those 18 bytes earlier, upon entering the shortcut (in other words, - * there is a combined check for both stages). - */ - if ( (endOnInput ? length != RUN_MASK : length <= 8) - /* strictly "less than" on input, to re-enter the loop with at least one byte */ - && likely((endOnInput ? ip < shortiend : 1) & (op <= shortoend)) ) { - /* Copy the literals */ - memcpy(op, ip, endOnInput ? 16 : 8); - op += length; ip += length; + /* Special cases */ + assert(lowPrefix <= op); + if ((endOnInput) && (unlikely(outputSize==0))) return ((srcSize==1) && (*ip==0)) ? 0 : -1; /* Empty output buffer */ + if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0 ? 1 : -1); + if ((endOnInput) && unlikely(srcSize==0)) return -1; - /* The second stage: prepare for match copying, decode full info. - * If it doesn't work out, the info won't be wasted. */ - length = token & ML_MASK; /* match length */ - offset = LZ4_readLE16(ip); ip += 2; + /* Currently the fast loop shows a regression on qualcomm arm chips. */ +#if LZ4_FAST_DEC_LOOP + if ((oend - op) < FASTLOOP_SAFE_DISTANCE) { + DEBUGLOG(6, "skip fast decode loop"); + goto safe_decode; + } + + /* Fast loop : decode sequences as long as output < iend-FASTLOOP_SAFE_DISTANCE */ + while (1) { + /* Main fastloop assertion: We can always wildcopy FASTLOOP_SAFE_DISTANCE */ + assert(oend - op >= FASTLOOP_SAFE_DISTANCE); + if (endOnInput) assert(ip < iend); + token = *ip++; + length = token >> ML_BITS; /* literal length */ + + assert(!endOnInput || ip <= iend); /* ip < iend before the increment */ + + /* decode literal length */ + if (length == RUN_MASK) { + variable_length_error error = ok; + length += read_variable_length(&ip, iend-RUN_MASK, endOnInput, endOnInput, &error); + if (error == initial_error) goto _output_error; + if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) goto _output_error; /* overflow detection */ + if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) goto _output_error; /* overflow detection */ + + /* copy literals */ + cpy = op+length; + LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH); + if (endOnInput) { /* LZ4_decompress_safe() */ + if ((cpy>oend-32) || (ip+length>iend-32)) goto safe_literal_copy; + LZ4_wildCopy32(op, ip, cpy); + } else { /* LZ4_decompress_fast() */ + if (cpy>oend-8) goto safe_literal_copy; + LZ4_wildCopy8(op, ip, cpy); /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time : + * it doesn't know input length, and only relies on end-of-block properties */ + } + ip += length; op = cpy; + } else { + cpy = op+length; + if (endOnInput) { /* LZ4_decompress_safe() */ + DEBUGLOG(7, "copy %u bytes in a 16-bytes stripe", (unsigned)length); + /* We don't need to check oend, since we check it once for each loop below */ + if (ip > iend-(16 + 1/*max lit + offset + nextToken*/)) goto safe_literal_copy; + /* Literals can only be 14, but hope compilers optimize if we copy by a register size */ + memcpy(op, ip, 16); + } else { /* LZ4_decompress_fast() */ + /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time : + * it doesn't know input length, and relies on end-of-block properties */ + memcpy(op, ip, 8); + if (length > 8) memcpy(op+8, ip+8, 8); + } + ip += length; op = cpy; + } + + /* get offset */ + offset = LZ4_readLE16(ip); ip+=2; match = op - offset; - assert(match <= op); /* check overflow */ - /* Do not deal with overlapping matches. */ - if ( (length != ML_MASK) - && (offset >= 8) - && (dict==withPrefix64k || match >= lowPrefix) ) { - /* Copy the match. */ - memcpy(op + 0, match + 0, 8); - memcpy(op + 8, match + 8, 8); - memcpy(op +16, match +16, 2); - op += length + MINMATCH; - /* Both stages worked, load the next token. */ + /* get matchlength */ + length = token & ML_MASK; + + if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) goto _output_error; /* Error : offset outside buffers */ + + if (length == ML_MASK) { + variable_length_error error = ok; + length += read_variable_length(&ip, iend - LASTLITERALS + 1, endOnInput, 0, &error); + if (error != ok) goto _output_error; + if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */ + length += MINMATCH; + if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) { + goto safe_match_copy; + } + } else { + length += MINMATCH; + if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) { + goto safe_match_copy; + } + + /* Fastpath check: Avoids a branch in LZ4_wildCopy32 if true */ + if (!(dict == usingExtDict) || (match >= lowPrefix)) { + if (offset >= 8) { + memcpy(op, match, 8); + memcpy(op+8, match+8, 8); + memcpy(op+16, match+16, 2); + op += length; + continue; + } } } + + /* match starting within external dictionary */ + if ((dict==usingExtDict) && (match < lowPrefix)) { + if (unlikely(op+length > oend-LASTLITERALS)) { + if (partialDecoding) length = MIN(length, (size_t)(oend-op)); + else goto _output_error; /* doesn't respect parsing restriction */ + } + + if (length <= (size_t)(lowPrefix-match)) { + /* match fits entirely within external dictionary : just copy */ + memmove(op, dictEnd - (lowPrefix-match), length); + op += length; + } else { + /* match stretches into both external dictionary and current block */ + size_t const copySize = (size_t)(lowPrefix - match); + size_t const restSize = length - copySize; + memcpy(op, dictEnd - copySize, copySize); + op += copySize; + if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */ + BYTE* const endOfMatch = op + restSize; + const BYTE* copyFrom = lowPrefix; + while (op < endOfMatch) *op++ = *copyFrom++; + } else { + memcpy(op, lowPrefix, restSize); + op += restSize; + } } continue; } - /* The second stage didn't work out, but the info is ready. - * Propel it right to the point of match copying. */ - goto _copy_match; - } + /* copy match within block */ + cpy = op + length; - /* decode literal length */ - if (length == RUN_MASK) { - unsigned s; - if (unlikely(endOnInput ? ip >= iend-RUN_MASK : 0)) goto _output_error; /* overflow detection */ - do { - s = *ip++; - length += s; - } while ( likely(endOnInput ? ip= WILDCOPYLENGTH); - if ( ((endOnInput) && ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS))) ) - || ((!endOnInput) && (cpy>oend-WILDCOPYLENGTH)) ) - { - if (partialDecoding) { - if (cpy > oend) { cpy = oend; length = oend-op; } /* Partial decoding : stop in the middle of literal segment */ - if ((endOnInput) && (ip+length > iend)) goto _output_error; /* Error : read attempt beyond end of input buffer */ + assert((op <= oend) && (oend-op >= 32)); + if (unlikely(offset<16)) { + LZ4_memcpy_using_offset(op, match, cpy, offset); } else { - if ((!endOnInput) && (cpy != oend)) goto _output_error; /* Error : block decoding must stop exactly there */ - if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error; /* Error : input must be consumed */ - } - memcpy(op, ip, length); - ip += length; - op += length; - if (!partialDecoding || (cpy == oend)) { - /* Necessarily EOF, due to parsing restrictions */ - break; + LZ4_wildCopy32(op, match, cpy); } - } else { - LZ4_wildCopy(op, ip, cpy); /* may overwrite up to WILDCOPYLENGTH beyond cpy */ - ip += length; op = cpy; + op = cpy; /* wildcopy correction */ } + safe_decode: +#endif - /* get offset */ - offset = LZ4_readLE16(ip); ip+=2; - match = op - offset; + /* Main Loop : decode remaining sequences where output < FASTLOOP_SAFE_DISTANCE */ + while (1) { + token = *ip++; + length = token >> ML_BITS; /* literal length */ - /* get matchlength */ - length = token & ML_MASK; + assert(!endOnInput || ip <= iend); /* ip < iend before the increment */ -_copy_match: - if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) goto _output_error; /* Error : offset outside buffers */ - if (!partialDecoding) { - assert(oend > op); - assert(oend - op >= 4); - LZ4_write32(op, 0); /* silence an msan warning when offset==0; costs <1%; */ - } /* note : when partialDecoding, there is no guarantee that at least 4 bytes remain available in output buffer */ + /* A two-stage shortcut for the most common case: + * 1) If the literal length is 0..14, and there is enough space, + * enter the shortcut and copy 16 bytes on behalf of the literals + * (in the fast mode, only 8 bytes can be safely copied this way). + * 2) Further if the match length is 4..18, copy 18 bytes in a similar + * manner; but we ensure that there's enough space in the output for + * those 18 bytes earlier, upon entering the shortcut (in other words, + * there is a combined check for both stages). + */ + if ( (endOnInput ? length != RUN_MASK : length <= 8) + /* strictly "less than" on input, to re-enter the loop with at least one byte */ + && likely((endOnInput ? ip < shortiend : 1) & (op <= shortoend)) ) { + /* Copy the literals */ + memcpy(op, ip, endOnInput ? 16 : 8); + op += length; ip += length; - if (length == ML_MASK) { - unsigned s; - do { - s = *ip++; - if ((endOnInput) && (ip > iend-LASTLITERALS)) goto _output_error; - length += s; - } while (s==255); - if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */ - } - length += MINMATCH; + /* The second stage: prepare for match copying, decode full info. + * If it doesn't work out, the info won't be wasted. */ + length = token & ML_MASK; /* match length */ + offset = LZ4_readLE16(ip); ip += 2; + match = op - offset; + assert(match <= op); /* check overflow */ - /* match starting within external dictionary */ - if ((dict==usingExtDict) && (match < lowPrefix)) { - if (unlikely(op+length > oend-LASTLITERALS)) { - if (partialDecoding) length = MIN(length, (size_t)(oend-op)); - else goto _output_error; /* doesn't respect parsing restriction */ + /* Do not deal with overlapping matches. */ + if ( (length != ML_MASK) + && (offset >= 8) + && (dict==withPrefix64k || match >= lowPrefix) ) { + /* Copy the match. */ + memcpy(op + 0, match + 0, 8); + memcpy(op + 8, match + 8, 8); + memcpy(op +16, match +16, 2); + op += length + MINMATCH; + /* Both stages worked, load the next token. */ + continue; + } + + /* The second stage didn't work out, but the info is ready. + * Propel it right to the point of match copying. */ + goto _copy_match; } - if (length <= (size_t)(lowPrefix-match)) { - /* match fits entirely within external dictionary : just copy */ - memmove(op, dictEnd - (lowPrefix-match), length); - op += length; - } else { - /* match stretches into both external dictionary and current block */ - size_t const copySize = (size_t)(lowPrefix - match); - size_t const restSize = length - copySize; - memcpy(op, dictEnd - copySize, copySize); - op += copySize; - if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */ - BYTE* const endOfMatch = op + restSize; - const BYTE* copyFrom = lowPrefix; - while (op < endOfMatch) *op++ = *copyFrom++; + /* decode literal length */ + if (length == RUN_MASK) { + variable_length_error error = ok; + length += read_variable_length(&ip, iend-RUN_MASK, endOnInput, endOnInput, &error); + if (error == initial_error) goto _output_error; + if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) goto _output_error; /* overflow detection */ + if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) goto _output_error; /* overflow detection */ + } + + /* copy literals */ + cpy = op+length; +#if LZ4_FAST_DEC_LOOP + safe_literal_copy: +#endif + LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH); + if ( ((endOnInput) && ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS))) ) + || ((!endOnInput) && (cpy>oend-WILDCOPYLENGTH)) ) + { + if (partialDecoding) { + if (cpy > oend) { cpy = oend; assert(op<=oend); length = (size_t)(oend-op); } /* Partial decoding : stop in the middle of literal segment */ + if ((endOnInput) && (ip+length > iend)) goto _output_error; /* Error : read attempt beyond end of input buffer */ } else { - memcpy(op, lowPrefix, restSize); - op += restSize; - } } - continue; - } + if ((!endOnInput) && (cpy != oend)) goto _output_error; /* Error : block decoding must stop exactly there */ + if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error; /* Error : input must be consumed */ + } + memcpy(op, ip, length); + ip += length; + op += length; + if (!partialDecoding || (cpy == oend)) { + /* Necessarily EOF, due to parsing restrictions */ + break; + } - /* copy match within block */ - cpy = op + length; - - /* partialDecoding : may not respect endBlock parsing restrictions */ - assert(op<=oend); - if (partialDecoding && (cpy > oend-MATCH_SAFEGUARD_DISTANCE)) { - size_t const mlen = MIN(length, (size_t)(oend-op)); - const BYTE* const matchEnd = match + mlen; - BYTE* const copyEnd = op + mlen; - if (matchEnd > op) { /* overlap copy */ - while (op < copyEnd) *op++ = *match++; } else { - memcpy(op, match, mlen); + LZ4_wildCopy8(op, ip, cpy); /* may overwrite up to WILDCOPYLENGTH beyond cpy */ + ip += length; op = cpy; } - op = copyEnd; - if (op==oend) break; - continue; + + /* get offset */ + offset = LZ4_readLE16(ip); ip+=2; + match = op - offset; + + /* get matchlength */ + length = token & ML_MASK; + + _copy_match: + if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) goto _output_error; /* Error : offset outside buffers */ + if (!partialDecoding) { + assert(oend > op); + assert(oend - op >= 4); + LZ4_write32(op, 0); /* silence an msan warning when offset==0; costs <1%; */ + } /* note : when partialDecoding, there is no guarantee that at least 4 bytes remain available in output buffer */ + + if (length == ML_MASK) { + variable_length_error error = ok; + length += read_variable_length(&ip, iend - LASTLITERALS + 1, endOnInput, 0, &error); + if (error != ok) goto _output_error; + if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */ + } + length += MINMATCH; + +#if LZ4_FAST_DEC_LOOP + safe_match_copy: +#endif + /* match starting within external dictionary */ + if ((dict==usingExtDict) && (match < lowPrefix)) { + if (unlikely(op+length > oend-LASTLITERALS)) { + if (partialDecoding) length = MIN(length, (size_t)(oend-op)); + else goto _output_error; /* doesn't respect parsing restriction */ + } + + if (length <= (size_t)(lowPrefix-match)) { + /* match fits entirely within external dictionary : just copy */ + memmove(op, dictEnd - (lowPrefix-match), length); + op += length; + } else { + /* match stretches into both external dictionary and current block */ + size_t const copySize = (size_t)(lowPrefix - match); + size_t const restSize = length - copySize; + memcpy(op, dictEnd - copySize, copySize); + op += copySize; + if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */ + BYTE* const endOfMatch = op + restSize; + const BYTE* copyFrom = lowPrefix; + while (op < endOfMatch) *op++ = *copyFrom++; + } else { + memcpy(op, lowPrefix, restSize); + op += restSize; + } } + continue; + } + + /* copy match within block */ + cpy = op + length; + + /* partialDecoding : may end anywhere within the block */ + assert(op<=oend); + if (partialDecoding && (cpy > oend-MATCH_SAFEGUARD_DISTANCE)) { + size_t const mlen = MIN(length, (size_t)(oend-op)); + const BYTE* const matchEnd = match + mlen; + BYTE* const copyEnd = op + mlen; + if (matchEnd > op) { /* overlap copy */ + while (op < copyEnd) *op++ = *match++; + } else { + memcpy(op, match, mlen); + } + op = copyEnd; + if (op==oend) break; + continue; + } + + if (unlikely(offset<8)) { + op[0] = match[0]; + op[1] = match[1]; + op[2] = match[2]; + op[3] = match[3]; + match += inc32table[offset]; + memcpy(op+4, match, 4); + match -= dec64table[offset]; + } else { + memcpy(op, match, 8); + match += 8; + } + op += 8; + + if (unlikely(cpy > oend-MATCH_SAFEGUARD_DISTANCE)) { + BYTE* const oCopyLimit = oend - (WILDCOPYLENGTH-1); + if (cpy > oend-LASTLITERALS) goto _output_error; /* Error : last LASTLITERALS bytes must be literals (uncompressed) */ + if (op < oCopyLimit) { + LZ4_wildCopy8(op, match, oCopyLimit); + match += oCopyLimit - op; + op = oCopyLimit; + } + while (op < cpy) *op++ = *match++; + } else { + memcpy(op, match, 8); + if (length > 16) LZ4_wildCopy8(op+8, match+8, cpy); + } + op = cpy; /* wildcopy correction */ } - if (unlikely(offset<8)) { - op[0] = match[0]; - op[1] = match[1]; - op[2] = match[2]; - op[3] = match[3]; - match += inc32table[offset]; - memcpy(op+4, match, 4); - match -= dec64table[offset]; - } else { - memcpy(op, match, 8); - match += 8; - } - op += 8; + /* end of decoding */ + if (endOnInput) + return (int) (((char*)op)-dst); /* Nb of output bytes decoded */ + else + return (int) (((const char*)ip)-src); /* Nb of input bytes read */ - if (unlikely(cpy > oend-MATCH_SAFEGUARD_DISTANCE)) { - BYTE* const oCopyLimit = oend - (WILDCOPYLENGTH-1); - if (cpy > oend-LASTLITERALS) goto _output_error; /* Error : last LASTLITERALS bytes must be literals (uncompressed) */ - if (op < oCopyLimit) { - LZ4_wildCopy(op, match, oCopyLimit); - match += oCopyLimit - op; - op = oCopyLimit; - } - while (op < cpy) *op++ = *match++; - } else { - memcpy(op, match, 8); - if (length > 16) LZ4_wildCopy(op+8, match+8, cpy); - } - op = cpy; /* wildcopy correction */ + /* Overflow error detected */ + _output_error: + return (int) (-(((const char*)ip)-src))-1; } - - /* end of decoding */ - if (endOnInput) - return (int) (((char*)op)-dst); /* Nb of output bytes decoded */ - else - return (int) (((const char*)ip)-src); /* Nb of input bytes read */ - - /* Overflow error detected */ -_output_error: - return (int) (-(((const char*)ip)-src))-1; } @@ -1745,12 +2073,13 @@ int LZ4_decompress_fast_doubleDict(const char* source, char* dest, int originalS LZ4_streamDecode_t* LZ4_createStreamDecode(void) { LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOC_AND_ZERO(sizeof(LZ4_streamDecode_t)); + LZ4_STATIC_ASSERT(LZ4_STREAMDECODESIZE >= sizeof(LZ4_streamDecode_t_internal)); /* A compilation error here means LZ4_STREAMDECODESIZE is not large enough */ return lz4s; } int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream) { - if (!LZ4_stream) return 0; /* support free on NULL */ + if (LZ4_stream == NULL) return 0; /* support free on NULL */ FREEMEM(LZ4_stream); return 0; } @@ -1808,7 +2137,7 @@ int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch assert(lz4sd->extDictSize == 0); result = LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize); if (result <= 0) return result; - lz4sd->prefixSize = result; + lz4sd->prefixSize = (size_t)result; lz4sd->prefixEnd = (BYTE*)dest + result; } else if (lz4sd->prefixEnd == (BYTE*)dest) { /* They're rolling the current segment. */ @@ -1821,7 +2150,7 @@ int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch result = LZ4_decompress_safe_doubleDict(source, dest, compressedSize, maxOutputSize, lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize); if (result <= 0) return result; - lz4sd->prefixSize += result; + lz4sd->prefixSize += (size_t)result; lz4sd->prefixEnd += result; } else { /* The buffer wraps around, or they're switching to another buffer. */ @@ -1830,7 +2159,7 @@ int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch result = LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize, lz4sd->externalDict, lz4sd->extDictSize); if (result <= 0) return result; - lz4sd->prefixSize = result; + lz4sd->prefixSize = (size_t)result; lz4sd->prefixEnd = (BYTE*)dest + result; } @@ -1842,12 +2171,13 @@ int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch { LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse; int result; + assert(originalSize >= 0); if (lz4sd->prefixSize == 0) { assert(lz4sd->extDictSize == 0); result = LZ4_decompress_fast(source, dest, originalSize); if (result <= 0) return result; - lz4sd->prefixSize = originalSize; + lz4sd->prefixSize = (size_t)originalSize; lz4sd->prefixEnd = (BYTE*)dest + originalSize; } else if (lz4sd->prefixEnd == (BYTE*)dest) { if (lz4sd->prefixSize >= 64 KB - 1 || lz4sd->extDictSize == 0) @@ -1856,7 +2186,7 @@ int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch result = LZ4_decompress_fast_doubleDict(source, dest, originalSize, lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize); if (result <= 0) return result; - lz4sd->prefixSize += originalSize; + lz4sd->prefixSize += (size_t)originalSize; lz4sd->prefixEnd += originalSize; } else { lz4sd->extDictSize = lz4sd->prefixSize; @@ -1864,7 +2194,7 @@ int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch result = LZ4_decompress_fast_extDict(source, dest, originalSize, lz4sd->externalDict, lz4sd->extDictSize); if (result <= 0) return result; - lz4sd->prefixSize = originalSize; + lz4sd->prefixSize = (size_t)originalSize; lz4sd->prefixEnd = (BYTE*)dest + originalSize; } diff --git a/C/lz4/lz4.h b/C/lz4/lz4.h index 059ef7c1..a9c932cc 100644 --- a/C/lz4/lz4.h +++ b/C/lz4/lz4.h @@ -51,19 +51,23 @@ extern "C" { multiple GB/s per core, typically reaching RAM speed limits on multi-core systems. The LZ4 compression library provides in-memory compression and decompression functions. + It gives full buffer control to user. Compression can be done in: - a single step (described as Simple Functions) - a single step, reusing a context (described in Advanced Functions) - unbounded multiple steps (described as Streaming compression) - lz4.h provides block compression functions. It gives full buffer control to user. - Decompressing an lz4-compressed block also requires metadata (such as compressed size). - Each application is free to encode such metadata in whichever way it wants. + lz4.h generates and decodes LZ4-compressed blocks (doc/lz4_Block_format.md). + Decompressing a block requires additional metadata, such as its compressed size. + Each application is free to encode and pass such metadata in whichever way it wants. - An additional format, called LZ4 frame specification (doc/lz4_Frame_format.md), - take care of encoding standard metadata alongside LZ4-compressed blocks. - Frame format is required for interoperability. - It is delivered through a companion API, declared in lz4frame.h. + lz4.h only handle blocks, it can not generate Frames. + + Blocks are different from Frames (doc/lz4_Frame_format.md). + Frames bundle both blocks and metadata in a specified manner. + This are required for compressed data to be self-contained and portable. + Frame format is delivered through a companion API, declared in lz4frame.h. + Note that the `lz4` CLI can only manage frames. */ /*^*************************************************************** @@ -92,8 +96,8 @@ extern "C" { /*------ Version ------*/ #define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */ -#define LZ4_VERSION_MINOR 8 /* for new (non-breaking) interface capabilities */ -#define LZ4_VERSION_RELEASE 3 /* for tweaks, bug-fixes, or development */ +#define LZ4_VERSION_MINOR 9 /* for new (non-breaking) interface capabilities */ +#define LZ4_VERSION_RELEASE 1 /* for tweaks, bug-fixes, or development */ #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE) @@ -103,7 +107,7 @@ extern "C" { #define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION) LZ4LIB_API int LZ4_versionNumber (void); /**< library version number; useful to check dll version */ -LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; unseful to check dll version */ +LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; useful to check dll version */ /*-************************************ @@ -112,14 +116,15 @@ LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; /*! * LZ4_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 may improve speed, thanks to cache effect + * Increasing memory usage improves compression ratio. + * Reduced memory usage may improve speed, thanks to better cache locality. * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */ #ifndef LZ4_MEMORY_USAGE # define LZ4_MEMORY_USAGE 14 #endif + /*-************************************ * Simple Functions **************************************/ @@ -130,21 +135,22 @@ LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; It also runs faster, so it's a recommended setting. If the function cannot compress 'src' into a more limited 'dst' budget, compression stops *immediately*, and the function result is zero. - Note : as a consequence, 'dst' content is not valid. - Note 2 : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer). + In which case, 'dst' content is undefined (invalid). srcSize : max supported value is LZ4_MAX_INPUT_SIZE. dstCapacity : size of buffer 'dst' (which must be already allocated) - return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity) - or 0 if compression fails */ + @return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity) + or 0 if compression fails + Note : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer). +*/ LZ4LIB_API int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity); /*! LZ4_decompress_safe() : compressedSize : is the exact complete size of the compressed block. dstCapacity : is the size of destination buffer, which must be already allocated. - return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity) + @return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity) If destination buffer is not large enough, decoding will stop and output an error code (negative value). If the source stream is detected malformed, the function will stop decoding and return a negative result. - This function is protected against malicious data packets. + Note : This function is protected against malicious data packets (never writes outside 'dst' buffer, nor read outside 'source' buffer). */ LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSize, int dstCapacity); @@ -155,8 +161,7 @@ LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSi #define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */ #define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16) -/*! -LZ4_compressBound() : +/*! LZ4_compressBound() : Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible) This function is primarily useful for memory allocation purposes (destination buffer size). Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example). @@ -167,8 +172,7 @@ LZ4_compressBound() : */ LZ4LIB_API int LZ4_compressBound(int inputSize); -/*! -LZ4_compress_fast() : +/*! LZ4_compress_fast() : Same as LZ4_compress_default(), but allows selection of "acceleration" factor. The larger the acceleration value, the faster the algorithm, but also the lesser the compression. It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed. @@ -178,13 +182,12 @@ LZ4_compress_fast() : LZ4LIB_API int LZ4_compress_fast (const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); -/*! -LZ4_compress_fast_extState() : - Same compression function, just using an externally allocated memory space to store compression state. - Use LZ4_sizeofState() to know how much memory must be allocated, - and allocate it on 8-bytes boundaries (using malloc() typically). - Then, provide this buffer as 'void* state' to compression function. -*/ +/*! LZ4_compress_fast_extState() : + * Same as LZ4_compress_fast(), using an externally allocated memory space for its state. + * Use LZ4_sizeofState() to know how much memory must be allocated, + * and allocate it on 8-bytes boundaries (using `malloc()` typically). + * Then, provide this buffer as `void* state` to compression function. + */ LZ4LIB_API int LZ4_sizeofState(void); LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); @@ -204,27 +207,6 @@ LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* d LZ4LIB_API int LZ4_compress_destSize (const char* src, char* dst, int* srcSizePtr, int targetDstSize); -/*! LZ4_decompress_fast() : **unsafe!** - * This function used to be a bit faster than LZ4_decompress_safe(), - * though situation has changed in recent versions, - * and now `LZ4_decompress_safe()` can be as fast and sometimes faster than `LZ4_decompress_fast()`. - * Moreover, LZ4_decompress_fast() is not protected vs malformed input, as it doesn't perform full validation of compressed data. - * As a consequence, this function is no longer recommended, and may be deprecated in future versions. - * It's only remaining specificity is that it can decompress data without knowing its compressed size. - * - * originalSize : is the uncompressed size to regenerate. - * `dst` must be already allocated, its size must be >= 'originalSize' bytes. - * @return : number of bytes read from source buffer (== compressed size). - * If the source stream is detected malformed, the function stops decoding and returns a negative result. - * note : This function requires uncompressed originalSize to be known in advance. - * The function never writes past the output buffer. - * However, since it doesn't know its 'src' size, it may read past the intended input. - * Also, because match offsets are not validated during decoding, - * reads from 'src' may underflow. - * Use this function in trusted environment **only**. - */ -LZ4LIB_API int LZ4_decompress_fast (const char* src, char* dst, int originalSize); - /*! LZ4_decompress_safe_partial() : * Decompress an LZ4 compressed block, of size 'srcSize' at position 'src', * into destination buffer 'dst' of size 'dstCapacity'. @@ -257,30 +239,49 @@ LZ4LIB_API int LZ4_decompress_safe_partial (const char* src, char* dst, int srcS ***********************************************/ typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */ -/*! LZ4_createStream() and LZ4_freeStream() : - * LZ4_createStream() will allocate and initialize an `LZ4_stream_t` structure. - * LZ4_freeStream() releases its memory. - */ LZ4LIB_API LZ4_stream_t* LZ4_createStream(void); LZ4LIB_API int LZ4_freeStream (LZ4_stream_t* streamPtr); -/*! LZ4_resetStream() : - * An LZ4_stream_t structure can be allocated once and re-used multiple times. - * Use this function to start compressing a new stream. +/*! LZ4_resetStream_fast() : v1.9.0+ + * Use this to prepare an LZ4_stream_t for a new chain of dependent blocks + * (e.g., LZ4_compress_fast_continue()). + * + * An LZ4_stream_t must be initialized once before usage. + * This is automatically done when created by LZ4_createStream(). + * However, should the LZ4_stream_t be simply declared on stack (for example), + * it's necessary to initialize it first, using LZ4_initStream(). + * + * After init, start any new stream with LZ4_resetStream_fast(). + * A same LZ4_stream_t can be re-used multiple times consecutively + * and compress multiple streams, + * provided that it starts each new stream with LZ4_resetStream_fast(). + * + * LZ4_resetStream_fast() is much faster than LZ4_initStream(), + * but is not compatible with memory regions containing garbage data. + * + * Note: it's only useful to call LZ4_resetStream_fast() + * in the context of streaming compression. + * The *extState* functions perform their own resets. + * Invoking LZ4_resetStream_fast() before is redundant, and even counterproductive. */ -LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr); +LZ4LIB_API void LZ4_resetStream_fast (LZ4_stream_t* streamPtr); /*! LZ4_loadDict() : - * Use this function to load a static dictionary into LZ4_stream_t. - * Any previous data will be forgotten, only 'dictionary' will remain in memory. + * Use this function to reference a static dictionary into LZ4_stream_t. + * The dictionary must remain available during compression. + * LZ4_loadDict() triggers a reset, so any previous data will be forgotten. + * The same dictionary will have to be loaded on decompression side for successful decoding. + * Dictionary are useful for better compression of small data (KB range). + * While LZ4 accept any input as dictionary, + * results are generally better when using Zstandard's Dictionary Builder. * Loading a size of 0 is allowed, and is the same as reset. - * @return : dictionary size, in bytes (necessarily <= 64 KB) + * @return : loaded dictionary size, in bytes (necessarily <= 64 KB) */ LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize); /*! LZ4_compress_fast_continue() : * Compress 'src' content using data from previously compressed blocks, for better compression ratio. - * 'dst' buffer must be already allocated. + * 'dst' buffer must be already allocated. * If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster. * * @return : size of compressed block @@ -288,10 +289,10 @@ LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, in * * Note 1 : Each invocation to LZ4_compress_fast_continue() generates a new block. * Each block has precise boundaries. + * Each block must be decompressed separately, calling LZ4_decompress_*() with relevant metadata. * It's not possible to append blocks together and expect a single invocation of LZ4_decompress_*() to decompress them together. - * Each block must be decompressed separately, calling LZ4_decompress_*() with associated metadata. * - * Note 2 : The previous 64KB of source data is __assumed__ to remain present, unmodified, at same address in memory! + * Note 2 : The previous 64KB of source data is __assumed__ to remain present, unmodified, at same address in memory ! * * Note 3 : When input is structured as a double-buffer, each buffer can have any size, including < 64 KB. * Make sure that buffers are separated, by at least one byte. @@ -299,7 +300,7 @@ LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, in * * Note 4 : If input buffer is a ring-buffer, it can have any size, including < 64 KB. * - * Note 5 : After an error, the stream status is invalid, it can only be reset or freed. + * Note 5 : After an error, the stream status is undefined (invalid), it can only be reset or freed. */ LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); @@ -335,7 +336,7 @@ LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_str */ LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize); -/*! LZ4_decoderRingBufferSize() : v1.8.2 +/*! LZ4_decoderRingBufferSize() : v1.8.2+ * Note : in a ring buffer scenario (optional), * blocks are presumed decompressed next to each other * up to the moment there is not enough remaining space for next block (remainingSize < maxBlockSize), @@ -347,7 +348,7 @@ LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const * or 0 if there is an error (invalid maxBlockSize). */ LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize); -#define LZ4_DECODER_RING_BUFFER_SIZE(mbs) (65536 + 14 + (mbs)) /* for static allocation; mbs presumed valid */ +#define LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize) (65536 + 14 + (maxBlockSize)) /* for static allocation; maxBlockSize presumed valid */ /*! LZ4_decompress_*_continue() : * These decoding functions allow decompression of consecutive blocks in "streaming" mode. @@ -375,83 +376,67 @@ LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize); * then indicate where this data is saved using LZ4_setStreamDecode(), before decompressing next block. */ LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int srcSize, int dstCapacity); -LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize); /*! LZ4_decompress_*_usingDict() : * These decoding functions work the same as * a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue() * They are stand-alone, and don't need an LZ4_streamDecode_t structure. - * Dictionary is presumed stable : it must remain accessible and unmodified during next decompression. + * Dictionary is presumed stable : it must remain accessible and unmodified during decompression. + * Performance tip : Decompression speed can be substantially increased + * when dst == dictStart + dictSize. */ LZ4LIB_API int LZ4_decompress_safe_usingDict (const char* src, char* dst, int srcSize, int dstCapcity, const char* dictStart, int dictSize); -LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize); -/*^********************************************** +/*^************************************* * !!!!!! STATIC LINKING ONLY !!!!!! - ***********************************************/ + ***************************************/ -/*-************************************ - * Unstable declarations - ************************************** - * Declarations in this section should be considered unstable. - * Use at your own peril, etc., etc. - * They may be removed in the future. - * Their signatures may change. - **************************************/ +/*-**************************************************************************** + * Experimental section + * + * Symbols declared in this section must be considered unstable. Their + * signatures or semantics may change, or they may be removed altogether in the + * future. They are therefore only safe to depend on when the caller is + * statically linked against the library. + * + * To protect against unsafe usage, not only are the declarations guarded, + * the definitions are hidden by default + * when building LZ4 as a shared/dynamic library. + * + * In order to access these declarations, + * define LZ4_STATIC_LINKING_ONLY in your application + * before including LZ4's headers. + * + * In order to make their implementations accessible dynamically, you must + * define LZ4_PUBLISH_STATIC_FUNCTIONS when building the LZ4 library. + ******************************************************************************/ + +#ifdef LZ4_PUBLISH_STATIC_FUNCTIONS +#define LZ4LIB_STATIC_API LZ4LIB_API +#else +#define LZ4LIB_STATIC_API +#endif #ifdef LZ4_STATIC_LINKING_ONLY -/*! LZ4_resetStream_fast() : - * Use this, like LZ4_resetStream(), to prepare a context for a new chain of - * calls to a streaming API (e.g., LZ4_compress_fast_continue()). - * - * Note: - * Using this in advance of a non- streaming-compression function is redundant, - * and potentially bad for performance, since they all perform their own custom - * reset internally. - * - * Differences from LZ4_resetStream(): - * When an LZ4_stream_t is known to be in a internally coherent state, - * it can often be prepared for a new compression with almost no work, only - * sometimes falling back to the full, expensive reset that is always required - * when the stream is in an indeterminate state (i.e., the reset performed by - * LZ4_resetStream()). - * - * LZ4_streams are guaranteed to be in a valid state when: - * - returned from LZ4_createStream() - * - reset by LZ4_resetStream() - * - memset(stream, 0, sizeof(LZ4_stream_t)), though this is discouraged - * - the stream was in a valid state and was reset by LZ4_resetStream_fast() - * - the stream was in a valid state and was then used in any compression call - * that returned success - * - the stream was in an indeterminate state and was used in a compression - * call that fully reset the state (e.g., LZ4_compress_fast_extState()) and - * that returned success - * - * When a stream isn't known to be in a valid state, it is not safe to pass to - * any fastReset or streaming function. It must first be cleansed by the full - * LZ4_resetStream(). - */ -LZ4LIB_API void LZ4_resetStream_fast (LZ4_stream_t* streamPtr); /*! LZ4_compress_fast_extState_fastReset() : * A variant of LZ4_compress_fast_extState(). * - * Using this variant avoids an expensive initialization step. It is only safe - * to call if the state buffer is known to be correctly initialized already - * (see above comment on LZ4_resetStream_fast() for a definition of "correctly - * initialized"). From a high level, the difference is that this function - * initializes the provided state with a call to something like - * LZ4_resetStream_fast() while LZ4_compress_fast_extState() starts with a - * call to LZ4_resetStream(). + * Using this variant avoids an expensive initialization step. + * It is only safe to call if the state buffer is known to be correctly initialized already + * (see above comment on LZ4_resetStream_fast() for a definition of "correctly initialized"). + * From a high level, the difference is that + * this function initializes the provided state with a call to something like LZ4_resetStream_fast() + * while LZ4_compress_fast_extState() starts with a call to LZ4_resetStream(). */ -LZ4LIB_API int LZ4_compress_fast_extState_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); +LZ4LIB_STATIC_API int LZ4_compress_fast_extState_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); /*! LZ4_attach_dictionary() : - * This is an experimental API that allows for the efficient use of a - * static dictionary many times. + * This is an experimental API that allows + * efficient use of a static dictionary many times. * * Rather than re-loading the dictionary buffer into a working context before * each compression, or copying a pre-loaded dictionary's LZ4_stream_t into a @@ -462,8 +447,8 @@ LZ4LIB_API int LZ4_compress_fast_extState_fastReset (void* state, const char* sr * Currently, only streams which have been prepared by LZ4_loadDict() should * be expected to work. * - * Alternatively, the provided dictionary stream pointer may be NULL, in which - * case any existing dictionary stream is unset. + * Alternatively, the provided dictionaryStream may be NULL, + * in which case any existing dictionary stream is unset. * * If a dictionary is provided, it replaces any pre-existing stream history. * The dictionary contents are the only history that can be referenced and @@ -475,17 +460,18 @@ LZ4LIB_API int LZ4_compress_fast_extState_fastReset (void* state, const char* sr * stream (and source buffer) must remain in-place / accessible / unchanged * through the completion of the first compression call on the stream. */ -LZ4LIB_API void LZ4_attach_dictionary(LZ4_stream_t *working_stream, const LZ4_stream_t *dictionary_stream); +LZ4LIB_STATIC_API void LZ4_attach_dictionary(LZ4_stream_t* workingStream, const LZ4_stream_t* dictionaryStream); #endif -/*-************************************ - * Private definitions - ************************************** - * Do not use these definitions. - * They are exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`. - * Using these definitions will expose code to API and/or ABI break in future versions of the library. - **************************************/ + +/*-************************************************************ + * PRIVATE DEFINITIONS + ************************************************************** + * Do not use these definitions directly. + * They are only exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`. + * Accessing members will expose code to API and/or ABI break in future versions of the library. + **************************************************************/ #define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2) #define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE) #define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */ @@ -497,7 +483,7 @@ typedef struct LZ4_stream_t_internal LZ4_stream_t_internal; struct LZ4_stream_t_internal { uint32_t hashTable[LZ4_HASH_SIZE_U32]; uint32_t currentOffset; - uint16_t initCheck; + uint16_t dirty; uint16_t tableType; const uint8_t* dictionary; const LZ4_stream_t_internal* dictCtx; @@ -517,7 +503,7 @@ typedef struct LZ4_stream_t_internal LZ4_stream_t_internal; struct LZ4_stream_t_internal { unsigned int hashTable[LZ4_HASH_SIZE_U32]; unsigned int currentOffset; - unsigned short initCheck; + unsigned short dirty; unsigned short tableType; const unsigned char* dictionary; const LZ4_stream_t_internal* dictCtx; @@ -526,38 +512,54 @@ struct LZ4_stream_t_internal { typedef struct { const unsigned char* externalDict; - size_t extDictSize; const unsigned char* prefixEnd; + size_t extDictSize; size_t prefixSize; } LZ4_streamDecode_t_internal; #endif -/*! - * LZ4_stream_t : - * information structure to track an LZ4 stream. - * init this structure before first use. - * note : only use in association with static linking ! - * this definition is not API/ABI safe, - * it may change in a future version ! +/*! LZ4_stream_t : + * information structure to track an LZ4 stream. + * LZ4_stream_t can also be created using LZ4_createStream(), which is recommended. + * The structure definition can be convenient for static allocation + * (on stack, or as part of larger structure). + * Init this structure with LZ4_initStream() before first use. + * note : only use this definition in association with static linking ! + * this definition is not API/ABI safe, and may change in a future version. */ -#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4) +#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4 + ((sizeof(void*)==16) ? 4 : 0) /*AS-400*/ ) #define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long)) union LZ4_stream_u { unsigned long long table[LZ4_STREAMSIZE_U64]; LZ4_stream_t_internal internal_donotuse; } ; /* previously typedef'd to LZ4_stream_t */ - -/*! - * LZ4_streamDecode_t : - * information structure to track an LZ4 stream during decompression. - * init this structure using LZ4_setStreamDecode (or memset()) before first use - * note : only use in association with static linking ! - * this definition is not API/ABI safe, - * and may change in a future version ! +/*! LZ4_initStream() : v1.9.0+ + * An LZ4_stream_t structure must be initialized at least once. + * This is automatically done when invoking LZ4_createStream(), + * but it's not when the structure is simply declared on stack (for example). + * + * Use LZ4_initStream() to properly initialize a newly declared LZ4_stream_t. + * It can also initialize any arbitrary buffer of sufficient size, + * and will @return a pointer of proper type upon initialization. + * + * Note : initialization fails if size and alignment conditions are not respected. + * In which case, the function will @return NULL. + * Note2: An LZ4_stream_t structure guarantees correct alignment and size. + * Note3: Before v1.9.0, use LZ4_resetStream() instead */ -#define LZ4_STREAMDECODESIZE_U64 4 +LZ4LIB_API LZ4_stream_t* LZ4_initStream (void* buffer, size_t size); + + +/*! LZ4_streamDecode_t : + * information structure to track an LZ4 stream during decompression. + * init this structure using LZ4_setStreamDecode() before first use. + * note : only use in association with static linking ! + * this definition is not API/ABI safe, + * and may change in a future version ! + */ +#define LZ4_STREAMDECODESIZE_U64 (4 + ((sizeof(void*)==16) ? 2 : 0) /*AS-400*/ ) #define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long)) union LZ4_streamDecode_u { unsigned long long table[LZ4_STREAMDECODESIZE_U64]; @@ -570,11 +572,16 @@ union LZ4_streamDecode_u { **************************************/ /*! Deprecation warnings - Should deprecation warnings be a problem, - it is generally possible to disable them, - typically with -Wno-deprecated-declarations for gcc - or _CRT_SECURE_NO_WARNINGS in Visual. - Otherwise, it's also possible to define LZ4_DISABLE_DEPRECATE_WARNINGS */ + * + * Deprecated functions make the compiler generate a warning when invoked. + * This is meant to invite users to update their source code. + * Should deprecation warnings be a problem, it is generally possible to disable them, + * typically with -Wno-deprecated-declarations for gcc + * or _CRT_SECURE_NO_WARNINGS in Visual. + * + * Another method is to define LZ4_DISABLE_DEPRECATE_WARNINGS + * before including the header file. + */ #ifdef LZ4_DISABLE_DEPRECATE_WARNINGS # define LZ4_DEPRECATED(message) /* disable deprecation warnings */ #else @@ -594,8 +601,8 @@ union LZ4_streamDecode_u { #endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */ /* Obsolete compression functions */ -LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress (const char* source, char* dest, int sourceSize); -LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize); +LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress (const char* source, char* dest, int sourceSize); +LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize); LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize); LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") LZ4LIB_API int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize); @@ -616,13 +623,57 @@ LZ4_DEPRECATED("use LZ4_decompress_safe() instead") LZ4LIB_API int LZ4_uncompres */ LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API void* LZ4_create (char* inputBuffer); LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API int LZ4_sizeofStreamState(void); -LZ4_DEPRECATED("Use LZ4_resetStream() instead") LZ4LIB_API int LZ4_resetStreamState(void* state, char* inputBuffer); -LZ4_DEPRECATED("Use LZ4_saveDict() instead") LZ4LIB_API char* LZ4_slideInputBuffer (void* state); +LZ4_DEPRECATED("Use LZ4_resetStream() instead") LZ4LIB_API int LZ4_resetStreamState(void* state, char* inputBuffer); +LZ4_DEPRECATED("Use LZ4_saveDict() instead") LZ4LIB_API char* LZ4_slideInputBuffer (void* state); /* Obsolete streaming decoding functions */ LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") LZ4LIB_API int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize); LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize); +/*! LZ4_decompress_fast() : **unsafe!** + * These functions used to be faster than LZ4_decompress_safe(), + * but it has changed, and they are now slower than LZ4_decompress_safe(). + * This is because LZ4_decompress_fast() doesn't know the input size, + * and therefore must progress more cautiously in the input buffer to not read beyond the end of block. + * On top of that `LZ4_decompress_fast()` is not protected vs malformed or malicious inputs, making it a security liability. + * As a consequence, LZ4_decompress_fast() is strongly discouraged, and deprecated. + * + * The last remaining LZ4_decompress_fast() specificity is that + * it can decompress a block without knowing its compressed size. + * Such functionality could be achieved in a more secure manner, + * by also providing the maximum size of input buffer, + * but it would require new prototypes, and adaptation of the implementation to this new use case. + * + * Parameters: + * originalSize : is the uncompressed size to regenerate. + * `dst` must be already allocated, its size must be >= 'originalSize' bytes. + * @return : number of bytes read from source buffer (== compressed size). + * The function expects to finish at block's end exactly. + * If the source stream is detected malformed, the function stops decoding and returns a negative result. + * note : LZ4_decompress_fast*() requires originalSize. Thanks to this information, it never writes past the output buffer. + * However, since it doesn't know its 'src' size, it may read an unknown amount of input, past input buffer bounds. + * Also, since match offsets are not validated, match reads from 'src' may underflow too. + * These issues never happen if input (compressed) data is correct. + * But they may happen if input data is invalid (error or intentional tampering). + * As a consequence, use these functions in trusted environments with trusted data **only**. + */ + +LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe() instead") +LZ4LIB_API int LZ4_decompress_fast (const char* src, char* dst, int originalSize); +LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_continue() instead") +LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize); +LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_usingDict() instead") +LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize); + +/*! LZ4_resetStream() : + * An LZ4_stream_t structure must be initialized at least once. + * This is done with LZ4_initStream(), or LZ4_resetStream(). + * Consider switching to LZ4_initStream(), + * invoking LZ4_resetStream() will trigger deprecation warnings in the future. + */ +LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr); + + #endif /* LZ4_H_2983827168210 */ diff --git a/C/lz4/lz4frame.c b/C/lz4/lz4frame.c index 5207f377..904508f8 100644 --- a/C/lz4/lz4frame.c +++ b/C/lz4/lz4frame.c @@ -1,41 +1,44 @@ /* -LZ4 auto-framing library -Copyright (C) 2011-2016, Yann Collet. - -BSD 2-Clause License (http://www.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 : -- LZ4 homepage : http://www.lz4.org -- LZ4 source repository : https://github.com/lz4/lz4 -*/ + * LZ4 auto-framing library + * Copyright (C) 2011-2016, Yann Collet. + * + * BSD 2-Clause License (http://www.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 : + * - LZ4 homepage : http://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 + */ /* LZ4F is a stand-alone API to create LZ4-compressed Frames -* in full conformance with specification v1.5.0 -* All related operations, including memory management, are handled by the library. -* */ + * in full conformance with specification v1.6.1 . + * This library rely upon memory management capabilities (malloc, free) + * provided either by , + * or redirected towards another library of user's choice + * (see Memory Routines below). + */ /*-************************************ @@ -62,16 +65,27 @@ You can contact the author at : /*-************************************ * Memory routines **************************************/ +/* + * User may redirect invocations of + * malloc(), calloc() and free() + * towards another library or solution of their choice + * by modifying below section. + */ #include /* malloc, calloc, free */ -#define ALLOC(s) malloc(s) -#define ALLOC_AND_ZERO(s) calloc(1,s) -#define FREEMEM free +#ifndef LZ4_SRC_INCLUDED /* avoid redefinition when sources are coalesced */ +# define ALLOC(s) malloc(s) +# define ALLOC_AND_ZERO(s) calloc(1,(s)) +# define FREEMEM(p) free(p) +#endif + #include /* memset, memcpy, memmove */ -#define MEM_INIT memset +#ifndef LZ4_SRC_INCLUDED /* avoid redefinition when sources are coalesced */ +# define MEM_INIT(p,v,s) memset((p),(v),(s)) +#endif /*-************************************ -* Includes +* Library declarations **************************************/ #define LZ4F_STATIC_LINKING_ONLY #include "lz4frame.h" @@ -134,8 +148,8 @@ static U32 LZ4F_readLE32 (const void* src) { const BYTE* const srcPtr = (const BYTE*)src; U32 value32 = srcPtr[0]; - value32 += (srcPtr[1]<<8); - value32 += (srcPtr[2]<<16); + value32 += ((U32)srcPtr[1])<< 8; + value32 += ((U32)srcPtr[2])<<16; value32 += ((U32)srcPtr[3])<<24; return value32; } @@ -180,9 +194,11 @@ static void LZ4F_writeLE64 (void* dst, U64 value64) /*-************************************ * Constants **************************************/ -#define KB *(1<<10) -#define MB *(1<<20) -#define GB *(1<<30) +#ifndef LZ4_SRC_INCLUDED /* avoid double definition */ +# define KB *(1<<10) +# define MB *(1<<20) +# define GB *(1<<30) +#endif #define _1BIT 0x01 #define _2BITS 0x03 @@ -195,9 +211,10 @@ static void LZ4F_writeLE64 (void* dst, U64 value64) #define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U #define LZ4F_BLOCKSIZEID_DEFAULT LZ4F_max64KB -static const size_t minFHSize = 7; +static const size_t minFHSize = LZ4F_HEADER_SIZE_MIN; /* 7 */ static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX; /* 19 */ -static const size_t BHSize = 4; +static const size_t BHSize = 4; /* block header : size, and compress flag */ +static const size_t BFSize = 4; /* block footer : checksum (optional) */ /*-************************************ @@ -258,22 +275,22 @@ unsigned LZ4F_getVersion(void) { return LZ4F_VERSION; } int LZ4F_compressionLevel_max(void) { return LZ4HC_CLEVEL_MAX; } +size_t LZ4F_getBlockSize(unsigned blockSizeID) +{ + static const size_t blockSizes[4] = { 64 KB, 256 KB, 1 MB, 4 MB }; + + if (blockSizeID == 0) blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT; + if (blockSizeID < LZ4F_max64KB || blockSizeID > LZ4F_max4MB) + return err0r(LZ4F_ERROR_maxBlockSize_invalid); + blockSizeID -= LZ4F_max64KB; + return blockSizes[blockSizeID]; +} /*-************************************ * Private functions **************************************/ #define MIN(a,b) ( (a) < (b) ? (a) : (b) ) -static size_t LZ4F_getBlockSize(unsigned blockSizeID) -{ - static const size_t blockSizes[4] = { 64 KB, 256 KB, 1 MB, 4 MB }; - - if (blockSizeID == 0) blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT; - blockSizeID -= 4; - if (blockSizeID > 3) return err0r(LZ4F_ERROR_maxBlockSize_invalid); - return blockSizes[blockSizeID]; -} - static BYTE LZ4F_headerChecksum (const void* header, size_t length) { U32 const xxh = XXH32(header, length, 0); @@ -308,8 +325,7 @@ static size_t LZ4F_compressBound_internal(size_t srcSize, const LZ4F_preferences_t* preferencesPtr, size_t alreadyBuffered) { - LZ4F_preferences_t prefsNull; - MEM_INIT(&prefsNull, 0, sizeof(prefsNull)); + LZ4F_preferences_t prefsNull = LZ4F_INIT_PREFERENCES; prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled; /* worst case */ { const LZ4F_preferences_t* const prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr; U32 const flush = prefsPtr->autoFlush | (srcSize==0); @@ -323,11 +339,10 @@ static size_t LZ4F_compressBound_internal(size_t srcSize, size_t const lastBlockSize = flush ? partialBlockSize : 0; unsigned const nbBlocks = nbFullBlocks + (lastBlockSize>0); - size_t const blockHeaderSize = 4; - size_t const blockCRCSize = 4 * prefsPtr->frameInfo.blockChecksumFlag; - size_t const frameEnd = 4 + (prefsPtr->frameInfo.contentChecksumFlag*4); + size_t const blockCRCSize = BFSize * prefsPtr->frameInfo.blockChecksumFlag; + size_t const frameEnd = BHSize + (prefsPtr->frameInfo.contentChecksumFlag*BFSize); - return ((blockHeaderSize + blockCRCSize) * nbBlocks) + + return ((BHSize + blockCRCSize) * nbBlocks) + (blockSize * nbFullBlocks) + lastBlockSize + frameEnd; } } @@ -388,15 +403,18 @@ size_t LZ4F_compressFrame_usingCDict(LZ4F_cctx* cctx, if (LZ4F_isError(headerSize)) return headerSize; dstPtr += headerSize; /* header size */ } - { size_t const cSize = LZ4F_compressUpdate(cctx, dstPtr, dstEnd-dstPtr, srcBuffer, srcSize, &options); + assert(dstEnd >= dstPtr); + { size_t const cSize = LZ4F_compressUpdate(cctx, dstPtr, (size_t)(dstEnd-dstPtr), srcBuffer, srcSize, &options); if (LZ4F_isError(cSize)) return cSize; dstPtr += cSize; } - { size_t const tailSize = LZ4F_compressEnd(cctx, dstPtr, dstEnd-dstPtr, &options); /* flush last block, and generate suffix */ + assert(dstEnd >= dstPtr); + { size_t const tailSize = LZ4F_compressEnd(cctx, dstPtr, (size_t)(dstEnd-dstPtr), &options); /* flush last block, and generate suffix */ if (LZ4F_isError(tailSize)) return tailSize; dstPtr += tailSize; } - return (dstPtr - dstStart); + assert(dstEnd >= dstStart); + return (size_t)(dstPtr - dstStart); } @@ -428,7 +446,7 @@ size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity, if (preferencesPtr == NULL || preferencesPtr->compressionLevel < LZ4HC_CLEVEL_MIN) { - LZ4_resetStream(&lz4ctx); + LZ4_initStream(&lz4ctx, sizeof(lz4ctx)); cctxPtr->lz4CtxPtr = &lz4ctx; cctxPtr->lz4CtxAlloc = 1; cctxPtr->lz4CtxState = 1; @@ -598,20 +616,22 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr, if (cctxPtr->lz4CtxAlloc < ctxTypeID) { FREEMEM(cctxPtr->lz4CtxPtr); if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) { - cctxPtr->lz4CtxPtr = (void*)LZ4_createStream(); + cctxPtr->lz4CtxPtr = LZ4_createStream(); } else { - cctxPtr->lz4CtxPtr = (void*)LZ4_createStreamHC(); + cctxPtr->lz4CtxPtr = LZ4_createStreamHC(); } - if (cctxPtr->lz4CtxPtr == NULL) return err0r(LZ4F_ERROR_allocation_failed); + if (cctxPtr->lz4CtxPtr == NULL) + return err0r(LZ4F_ERROR_allocation_failed); cctxPtr->lz4CtxAlloc = ctxTypeID; cctxPtr->lz4CtxState = ctxTypeID; } else if (cctxPtr->lz4CtxState != ctxTypeID) { /* otherwise, a sufficient buffer is allocated, but we need to * reset it to the correct context type */ if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) { - LZ4_resetStream((LZ4_stream_t *) cctxPtr->lz4CtxPtr); + LZ4_initStream((LZ4_stream_t *) cctxPtr->lz4CtxPtr, sizeof (LZ4_stream_t)); } else { - LZ4_resetStreamHC((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel); + LZ4_initStreamHC((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, sizeof(LZ4_streamHC_t)); + LZ4_setCompressionLevel((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel); } cctxPtr->lz4CtxState = ctxTypeID; } @@ -623,8 +643,8 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr, cctxPtr->maxBlockSize = LZ4F_getBlockSize(cctxPtr->prefs.frameInfo.blockSizeID); { size_t const requiredBuffSize = preferencesPtr->autoFlush ? - (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) * 64 KB : /* only needs windows size */ - cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) * 128 KB); + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 64 KB : 0) : /* only needs past data up to window size */ + cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 128 KB : 0); if (cctxPtr->maxBufferSize < requiredBuffSize) { cctxPtr->maxBufferSize = 0; @@ -635,7 +655,7 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr, } } cctxPtr->tmpIn = cctxPtr->tmpBuff; cctxPtr->tmpInSize = 0; - XXH32_reset(&(cctxPtr->xxh), 0); + (void)XXH32_reset(&(cctxPtr->xxh), 0); /* context init */ cctxPtr->cdict = cdict; @@ -644,7 +664,7 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr, LZ4F_initStream(cctxPtr->lz4CtxPtr, cdict, cctxPtr->prefs.compressionLevel, LZ4F_blockLinked); } if (preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN) { - LZ4_favorDecompressionSpeed((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, (int)preferencesPtr->favorDecSpeed); + LZ4_favorDecompressionSpeed((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, (int)preferencesPtr->favorDecSpeed); } /* Magic Number */ @@ -656,7 +676,7 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr, *dstPtr++ = (BYTE)(((1 & _2BITS) << 6) /* Version('01') */ + ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5) + ((cctxPtr->prefs.frameInfo.blockChecksumFlag & _1BIT ) << 4) - + ((cctxPtr->prefs.frameInfo.contentSize > 0) << 3) + + ((unsigned)(cctxPtr->prefs.frameInfo.contentSize > 0) << 3) + ((cctxPtr->prefs.frameInfo.contentChecksumFlag & _1BIT ) << 2) + (cctxPtr->prefs.frameInfo.dictID > 0) ); /* BD Byte */ @@ -673,11 +693,11 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr, dstPtr += 4; } /* Header CRC Byte */ - *dstPtr = LZ4F_headerChecksum(headerStart, dstPtr - headerStart); + *dstPtr = LZ4F_headerChecksum(headerStart, (size_t)(dstPtr - headerStart)); dstPtr++; cctxPtr->cStage = 1; /* header written, now request input data block */ - return (dstPtr - dstStart); + return (size_t)(dstPtr - dstStart); } @@ -686,7 +706,7 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr, * dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes. * preferencesPtr can be NULL, in which case default parameters are selected. * @return : number of bytes written into dstBuffer for the header - * or an error code (can be tested using LZ4F_isError()) + * or an error code (can be tested using LZ4F_isError()) */ size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, @@ -712,27 +732,31 @@ typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize /*! LZ4F_makeBlock(): - * compress a single block, add header and checksum - * assumption : dst buffer capacity is >= srcSize */ -static size_t LZ4F_makeBlock(void* dst, const void* src, size_t srcSize, + * compress a single block, add header and optional checksum. + * assumption : dst buffer capacity is >= BHSize + srcSize + crcSize + */ +static size_t LZ4F_makeBlock(void* dst, + const void* src, size_t srcSize, compressFunc_t compress, void* lz4ctx, int level, - const LZ4F_CDict* cdict, LZ4F_blockChecksum_t crcFlag) + const LZ4F_CDict* cdict, + LZ4F_blockChecksum_t crcFlag) { BYTE* const cSizePtr = (BYTE*)dst; - U32 cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+4), + U32 cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+BHSize), (int)(srcSize), (int)(srcSize-1), level, cdict); - LZ4F_writeLE32(cSizePtr, cSize); if (cSize == 0) { /* compression failed */ cSize = (U32)srcSize; LZ4F_writeLE32(cSizePtr, cSize | LZ4F_BLOCKUNCOMPRESSED_FLAG); - memcpy(cSizePtr+4, src, srcSize); + memcpy(cSizePtr+BHSize, src, srcSize); + } else { + LZ4F_writeLE32(cSizePtr, cSize); } if (crcFlag) { - U32 const crc32 = XXH32(cSizePtr+4, cSize, 0); /* checksum of compressed data */ - LZ4F_writeLE32(cSizePtr+4+cSize, crc32); + U32 const crc32 = XXH32(cSizePtr+BHSize, cSize, 0); /* checksum of compressed data */ + LZ4F_writeLE32(cSizePtr+BHSize+cSize, crc32); } - return 4 + cSize + ((U32)crcFlag)*4; + return BHSize + cSize + ((U32)crcFlag)*BFSize; } @@ -832,9 +856,11 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, sizeToCopy); srcPtr += sizeToCopy; - dstPtr += LZ4F_makeBlock(dstPtr, cctxPtr->tmpIn, blockSize, + dstPtr += LZ4F_makeBlock(dstPtr, + cctxPtr->tmpIn, blockSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel, - cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag); + cctxPtr->cdict, + cctxPtr->prefs.frameInfo.blockChecksumFlag); if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += blockSize; cctxPtr->tmpInSize = 0; @@ -844,18 +870,22 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, while ((size_t)(srcEnd - srcPtr) >= blockSize) { /* compress full blocks */ lastBlockCompressed = fromSrcBuffer; - dstPtr += LZ4F_makeBlock(dstPtr, srcPtr, blockSize, + dstPtr += LZ4F_makeBlock(dstPtr, + srcPtr, blockSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel, - cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag); + cctxPtr->cdict, + cctxPtr->prefs.frameInfo.blockChecksumFlag); srcPtr += blockSize; } if ((cctxPtr->prefs.autoFlush) && (srcPtr < srcEnd)) { /* compress remaining input < blockSize */ lastBlockCompressed = fromSrcBuffer; - dstPtr += LZ4F_makeBlock(dstPtr, srcPtr, srcEnd - srcPtr, + dstPtr += LZ4F_makeBlock(dstPtr, + srcPtr, (size_t)(srcEnd - srcPtr), compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel, - cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag); + cctxPtr->cdict, + cctxPtr->prefs.frameInfo.blockChecksumFlag); srcPtr = srcEnd; } @@ -881,28 +911,30 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, /* some input data left, necessarily < blockSize */ if (srcPtr < srcEnd) { /* fill tmp buffer */ - size_t const sizeToCopy = srcEnd - srcPtr; + size_t const sizeToCopy = (size_t)(srcEnd - srcPtr); memcpy(cctxPtr->tmpIn, srcPtr, sizeToCopy); cctxPtr->tmpInSize = sizeToCopy; } if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled) - XXH32_update(&(cctxPtr->xxh), srcBuffer, srcSize); + (void)XXH32_update(&(cctxPtr->xxh), srcBuffer, srcSize); cctxPtr->totalInSize += srcSize; - return dstPtr - dstStart; + return (size_t)(dstPtr - dstStart); } /*! LZ4F_flush() : - * Should you need to create compressed data immediately, without waiting for a block to be filled, - * you can call LZ4_flush(), which will immediately compress any remaining data stored within compressionContext. - * The result of the function is the number of bytes written into dstBuffer - * (it can be zero, this means there was no data left within compressionContext) + * When compressed data must be sent immediately, without waiting for a block to be filled, + * invoke LZ4_flush(), which will immediately compress any remaining data stored within LZ4F_cctx. + * The result of the function is the number of bytes written into dstBuffer. + * It can be zero, this means there was no data left within LZ4F_cctx. * The function outputs an error code if it fails (can be tested using LZ4F_isError()) - * The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. + * LZ4F_compressOptions_t* is optional. NULL is a valid argument. */ -size_t LZ4F_flush(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* compressOptionsPtr) +size_t LZ4F_flush(LZ4F_cctx* cctxPtr, + void* dstBuffer, size_t dstCapacity, + const LZ4F_compressOptions_t* compressOptionsPtr) { BYTE* const dstStart = (BYTE*)dstBuffer; BYTE* dstPtr = dstStart; @@ -910,52 +942,65 @@ size_t LZ4F_flush(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const if (cctxPtr->tmpInSize == 0) return 0; /* nothing to flush */ if (cctxPtr->cStage != 1) return err0r(LZ4F_ERROR_GENERIC); - if (dstCapacity < (cctxPtr->tmpInSize + 4)) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); /* +4 : block header(4) */ + if (dstCapacity < (cctxPtr->tmpInSize + BHSize + BFSize)) + return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); (void)compressOptionsPtr; /* not yet useful */ /* select compression function */ compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel); /* compress tmp buffer */ - dstPtr += LZ4F_makeBlock(dstPtr, cctxPtr->tmpIn, cctxPtr->tmpInSize, + dstPtr += LZ4F_makeBlock(dstPtr, + cctxPtr->tmpIn, cctxPtr->tmpInSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel, - cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag); - if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += cctxPtr->tmpInSize; + cctxPtr->cdict, + cctxPtr->prefs.frameInfo.blockChecksumFlag); + assert(((void)"flush overflows dstBuffer!", (size_t)(dstPtr - dstStart) <= dstCapacity)); + + if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) + cctxPtr->tmpIn += cctxPtr->tmpInSize; cctxPtr->tmpInSize = 0; /* keep tmpIn within limits */ if ((cctxPtr->tmpIn + cctxPtr->maxBlockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize)) { /* necessarily LZ4F_blockLinked */ - int realDictSize = LZ4F_localSaveDict(cctxPtr); + int const realDictSize = LZ4F_localSaveDict(cctxPtr); cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize; } - return dstPtr - dstStart; + return (size_t)(dstPtr - dstStart); } /*! LZ4F_compressEnd() : - * When you want to properly finish the compressed frame, just call LZ4F_compressEnd(). - * It will flush whatever data remained within compressionContext (like LZ4_flush()) - * but also properly finalize the frame, with an endMark and a checksum. - * The result of the function is the number of bytes written into dstBuffer (necessarily >= 4 (endMark size)) - * The function outputs an error code if it fails (can be tested using LZ4F_isError()) - * The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. - * compressionContext can then be used again, starting with LZ4F_compressBegin(). The preferences will remain the same. + * When you want to properly finish the compressed frame, just call LZ4F_compressEnd(). + * It will flush whatever data remained within compressionContext (like LZ4_flush()) + * but also properly finalize the frame, with an endMark and an (optional) checksum. + * LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. + * @return: the number of bytes written into dstBuffer (necessarily >= 4 (endMark size)) + * or an error code if it fails (can be tested using LZ4F_isError()) + * The context can then be used again to compress a new frame, starting with LZ4F_compressBegin(). */ -size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstMaxSize, const LZ4F_compressOptions_t* compressOptionsPtr) +size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr, + void* dstBuffer, size_t dstCapacity, + const LZ4F_compressOptions_t* compressOptionsPtr) { BYTE* const dstStart = (BYTE*)dstBuffer; BYTE* dstPtr = dstStart; - size_t const flushSize = LZ4F_flush(cctxPtr, dstBuffer, dstMaxSize, compressOptionsPtr); + size_t const flushSize = LZ4F_flush(cctxPtr, dstBuffer, dstCapacity, compressOptionsPtr); if (LZ4F_isError(flushSize)) return flushSize; dstPtr += flushSize; + assert(flushSize <= dstCapacity); + dstCapacity -= flushSize; + + if (dstCapacity < 4) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); LZ4F_writeLE32(dstPtr, 0); - dstPtr+=4; /* endMark */ + dstPtr += 4; /* endMark */ if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled) { U32 const xxh = XXH32_digest(&(cctxPtr->xxh)); + if (dstCapacity < 8) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); LZ4F_writeLE32(dstPtr, xxh); dstPtr+=4; /* content Checksum */ } @@ -968,7 +1013,7 @@ size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstMaxSize, return err0r(LZ4F_ERROR_frameSize_wrong); } - return dstPtr - dstStart; + return (size_t)(dstPtr - dstStart); } @@ -1019,7 +1064,10 @@ struct LZ4F_dctx_s { LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** LZ4F_decompressionContextPtr, unsigned versionNumber) { LZ4F_dctx* const dctx = (LZ4F_dctx*)ALLOC_AND_ZERO(sizeof(LZ4F_dctx)); - if (dctx==NULL) return err0r(LZ4F_ERROR_GENERIC); + if (dctx == NULL) { /* failed allocation */ + *LZ4F_decompressionContextPtr = NULL; + return err0r(LZ4F_ERROR_allocation_failed); + } dctx->version = versionNumber; *LZ4F_decompressionContextPtr = dctx; @@ -1049,31 +1097,6 @@ void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx) } -/*! LZ4F_headerSize() : - * @return : size of frame header - * or an error code, which can be tested using LZ4F_isError() - */ -static size_t LZ4F_headerSize(const void* src, size_t srcSize) -{ - /* minimal srcSize to determine header size */ - if (srcSize < 5) return err0r(LZ4F_ERROR_frameHeader_incomplete); - - /* special case : skippable frames */ - if ((LZ4F_readLE32(src) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) return 8; - - /* control magic number */ - if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER) - return err0r(LZ4F_ERROR_frameType_unknown); - - /* Frame Header Size */ - { BYTE const FLG = ((const BYTE*)src)[4]; - U32 const contentSizeFlag = (FLG>>3) & _1BIT; - U32 const dictIDFlag = FLG & _1BIT; - return minFHSize + (contentSizeFlag*8) + (dictIDFlag*4); - } -} - - /*! LZ4F_decodeHeader() : * input : `src` points at the **beginning of the frame** * output : set internal values of dctx, such as @@ -1125,7 +1148,7 @@ static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize } /* Frame Header Size */ - frameHeaderSize = minFHSize + (contentSizeFlag*8) + (dictIDFlag*4); + frameHeaderSize = minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0); if (srcSize < frameHeaderSize) { /* not enough input to fully decode frame header */ @@ -1146,6 +1169,7 @@ static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize } /* check header */ + assert(frameHeaderSize > 5); { BYTE const HC = LZ4F_headerChecksum(srcPtr+4, frameHeaderSize-5); if (HC != srcPtr[frameHeaderSize-1]) return err0r(LZ4F_ERROR_headerChecksum_invalid); @@ -1169,6 +1193,34 @@ static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize } +/*! LZ4F_headerSize() : + * @return : size of frame header + * or an error code, which can be tested using LZ4F_isError() + */ +size_t LZ4F_headerSize(const void* src, size_t srcSize) +{ + if (src == NULL) return err0r(LZ4F_ERROR_srcPtr_wrong); + + /* minimal srcSize to determine header size */ + if (srcSize < LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH) + return err0r(LZ4F_ERROR_frameHeader_incomplete); + + /* special case : skippable frames */ + if ((LZ4F_readLE32(src) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) + return 8; + + /* control magic number */ + if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER) + return err0r(LZ4F_ERROR_frameType_unknown); + + /* Frame Header Size */ + { BYTE const FLG = ((const BYTE*)src)[4]; + U32 const contentSizeFlag = (FLG>>3) & _1BIT; + U32 const dictIDFlag = FLG & _1BIT; + return minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0); + } +} + /*! LZ4F_getFrameInfo() : * This function extracts frame parameters (max blockSize, frame checksum, etc.). * Usage is optional. Objective is to provide relevant information for allocation purposes. @@ -1184,10 +1236,12 @@ static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize * note 1 : in case of error, dctx is not modified. Decoding operations can resume from where they stopped. * note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure. */ -LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx, LZ4F_frameInfo_t* frameInfoPtr, - const void* srcBuffer, size_t* srcSizePtr) +LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx, + LZ4F_frameInfo_t* frameInfoPtr, + const void* srcBuffer, size_t* srcSizePtr) { - if (dctx->dStage > dstage_storeFrameHeader) { /* assumption : dstage_* header enum at beginning of range */ + LZ4F_STATIC_ASSERT(dstage_getFrameHeader < dstage_storeFrameHeader); + if (dctx->dStage > dstage_storeFrameHeader) { /* frameInfo already decoded */ size_t o=0, i=0; *srcSizePtr = 0; @@ -1200,7 +1254,6 @@ LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx, LZ4F_frameInfo_t* frameInfoP *srcSizePtr = 0; return err0r(LZ4F_ERROR_frameDecoding_alreadyStarted); } else { - size_t decodeResult; size_t const hSize = LZ4F_headerSize(srcBuffer, *srcSizePtr); if (LZ4F_isError(hSize)) { *srcSizePtr=0; return hSize; } if (*srcSizePtr < hSize) { @@ -1208,16 +1261,16 @@ LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx, LZ4F_frameInfo_t* frameInfoP return err0r(LZ4F_ERROR_frameHeader_incomplete); } - decodeResult = LZ4F_decodeHeader(dctx, srcBuffer, hSize); - if (LZ4F_isError(decodeResult)) { - *srcSizePtr = 0; - } else { - *srcSizePtr = decodeResult; - decodeResult = BHSize; /* block header size */ - } - *frameInfoPtr = dctx->frameInfo; - return decodeResult; - } } + { size_t decodeResult = LZ4F_decodeHeader(dctx, srcBuffer, hSize); + if (LZ4F_isError(decodeResult)) { + *srcSizePtr = 0; + } else { + *srcSizePtr = decodeResult; + decodeResult = BHSize; /* block header size */ + } + *frameInfoPtr = dctx->frameInfo; + return decodeResult; + } } } } @@ -1235,9 +1288,10 @@ static void LZ4F_updateDict(LZ4F_dctx* dctx, return; } - if (dstPtr - dstBufferStart + dstSize >= 64 KB) { /* history in dstBuffer becomes large enough to become dictionary */ + assert(dstPtr >= dstBufferStart); + if ((size_t)(dstPtr - dstBufferStart) + dstSize >= 64 KB) { /* history in dstBuffer becomes large enough to become dictionary */ dctx->dict = (const BYTE*)dstBufferStart; - dctx->dictSize = dstPtr - dstBufferStart + dstSize; + dctx->dictSize = (size_t)(dstPtr - dstBufferStart) + dstSize; return; } @@ -1253,7 +1307,7 @@ static void LZ4F_updateDict(LZ4F_dctx* dctx, } if (withinTmp) { /* copy relevant dict portion in front of tmpOut within tmpOutBuffer */ - size_t const preserveSize = dctx->tmpOut - dctx->tmpOutBuffer; + size_t const preserveSize = (size_t)(dctx->tmpOut - dctx->tmpOutBuffer); size_t copySize = 64 KB - dctx->tmpOutSize; const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart; if (dctx->tmpOutSize > 64 KB) copySize = 0; @@ -1338,7 +1392,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, case dstage_getFrameHeader: if ((size_t)(srcEnd-srcPtr) >= maxFHSize) { /* enough to decode - shortcut */ - size_t const hSize = LZ4F_decodeHeader(dctx, srcPtr, srcEnd-srcPtr); /* will update dStage appropriately */ + size_t const hSize = LZ4F_decodeHeader(dctx, srcPtr, (size_t)(srcEnd-srcPtr)); /* will update dStage appropriately */ if (LZ4F_isError(hSize)) return hSize; srcPtr += hSize; break; @@ -1366,14 +1420,14 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, break; case dstage_init: - if (dctx->frameInfo.contentChecksumFlag) XXH32_reset(&(dctx->xxh), 0); + if (dctx->frameInfo.contentChecksumFlag) (void)XXH32_reset(&(dctx->xxh), 0); /* internal buffers allocation */ { size_t const bufferNeeded = dctx->maxBlockSize - + ((dctx->frameInfo.blockMode==LZ4F_blockLinked) * 128 KB); + + ((dctx->frameInfo.blockMode==LZ4F_blockLinked) ? 128 KB : 0); if (bufferNeeded > dctx->maxBufferSize) { /* tmp buffers too small */ dctx->maxBufferSize = 0; /* ensure allocation will be re-attempted on next entry*/ FREEMEM(dctx->tmpIn); - dctx->tmpIn = (BYTE*)ALLOC(dctx->maxBlockSize + 4 /* block checksum */); + dctx->tmpIn = (BYTE*)ALLOC(dctx->maxBlockSize + BFSize /* block checksum */); if (dctx->tmpIn == NULL) return err0r(LZ4F_ERROR_allocation_failed); FREEMEM(dctx->tmpOutBuffer); @@ -1420,7 +1474,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, /* decode block header */ { size_t const nextCBlockSize = LZ4F_readLE32(selectedIn) & 0x7FFFFFFFU; - size_t const crcSize = dctx->frameInfo.blockChecksumFlag * 4; + size_t const crcSize = dctx->frameInfo.blockChecksumFlag * BFSize; if (nextCBlockSize==0) { /* frameEnd signal, no more block */ dctx->dStage = dstage_getSuffix; break; @@ -1431,7 +1485,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, /* next block is uncompressed */ dctx->tmpInTarget = nextCBlockSize; if (dctx->frameInfo.blockChecksumFlag) { - XXH32_reset(&dctx->blockChecksum, 0); + (void)XXH32_reset(&dctx->blockChecksum, 0); } dctx->dStage = dstage_copyDirect; break; @@ -1440,7 +1494,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, dctx->tmpInTarget = nextCBlockSize + crcSize; dctx->dStage = dstage_getCBlock; if (dstPtr==dstEnd) { - nextSrcSizeHint = nextCBlockSize + crcSize + BHSize; + nextSrcSizeHint = BHSize + nextCBlockSize + crcSize; doAnotherStage = 0; } break; @@ -1451,10 +1505,10 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, size_t const sizeToCopy = MIN(dctx->tmpInTarget, minBuffSize); memcpy(dstPtr, srcPtr, sizeToCopy); if (dctx->frameInfo.blockChecksumFlag) { - XXH32_update(&dctx->blockChecksum, srcPtr, sizeToCopy); + (void)XXH32_update(&dctx->blockChecksum, srcPtr, sizeToCopy); } if (dctx->frameInfo.contentChecksumFlag) - XXH32_update(&dctx->xxh, srcPtr, sizeToCopy); + (void)XXH32_update(&dctx->xxh, srcPtr, sizeToCopy); if (dctx->frameInfo.contentSize) dctx->frameRemainingSize -= sizeToCopy; @@ -1474,7 +1528,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, } dctx->tmpInTarget -= sizeToCopy; /* need to copy more */ nextSrcSizeHint = dctx->tmpInTarget + - + dctx->frameInfo.contentChecksumFlag * 4 /* block checksum */ + +(dctx->frameInfo.blockChecksumFlag ? BFSize : 0) + BHSize /* next header size */; doAnotherStage = 0; break; @@ -1525,8 +1579,10 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, dctx->tmpInSize += sizeToCopy; srcPtr += sizeToCopy; if (dctx->tmpInSize < dctx->tmpInTarget) { /* need more input */ - nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + BHSize; - doAnotherStage=0; + nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + + (dctx->frameInfo.blockChecksumFlag ? BFSize : 0) + + BHSize /* next header size */; + doAnotherStage = 0; break; } selectedIn = dctx->tmpIn; @@ -1558,13 +1614,13 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, dict, (int)dictSize); if (decodedSize < 0) return err0r(LZ4F_ERROR_GENERIC); /* decompression failed */ if (dctx->frameInfo.contentChecksumFlag) - XXH32_update(&(dctx->xxh), dstPtr, decodedSize); + XXH32_update(&(dctx->xxh), dstPtr, (size_t)decodedSize); if (dctx->frameInfo.contentSize) - dctx->frameRemainingSize -= decodedSize; + dctx->frameRemainingSize -= (size_t)decodedSize; /* dictionary management */ if (dctx->frameInfo.blockMode==LZ4F_blockLinked) - LZ4F_updateDict(dctx, dstPtr, decodedSize, dstStart, 0); + LZ4F_updateDict(dctx, dstPtr, (size_t)decodedSize, dstStart, 0); dstPtr += decodedSize; dctx->dStage = dstage_getBlockHeader; @@ -1601,10 +1657,10 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, if (decodedSize < 0) /* decompression failed */ return err0r(LZ4F_ERROR_decompressionFailed); if (dctx->frameInfo.contentChecksumFlag) - XXH32_update(&(dctx->xxh), dctx->tmpOut, decodedSize); + XXH32_update(&(dctx->xxh), dctx->tmpOut, (size_t)decodedSize); if (dctx->frameInfo.contentSize) - dctx->frameRemainingSize -= decodedSize; - dctx->tmpOutSize = decodedSize; + dctx->frameRemainingSize -= (size_t)decodedSize; + dctx->tmpOutSize = (size_t)decodedSize; dctx->tmpOutStart = 0; dctx->dStage = dstage_flushOut; } @@ -1732,7 +1788,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, && ((unsigned)(dctx->dStage)-2 < (unsigned)(dstage_getSuffix)-2) ) /* valid stages : [init ... getSuffix[ */ { if (dctx->dStage == dstage_flushOut) { - size_t const preserveSize = dctx->tmpOut - dctx->tmpOutBuffer; + size_t const preserveSize = (size_t)(dctx->tmpOut - dctx->tmpOutBuffer); size_t copySize = 64 KB - dctx->tmpOutSize; const BYTE* oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart; if (dctx->tmpOutSize > 64 KB) copySize = 0; @@ -1756,8 +1812,8 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx, } } - *srcSizePtr = (srcPtr - srcStart); - *dstSizePtr = (dstPtr - dstStart); + *srcSizePtr = (size_t)(srcPtr - srcStart); + *dstSizePtr = (size_t)(dstPtr - dstStart); return nextSrcSizeHint; } diff --git a/C/lz4/lz4frame.h b/C/lz4/lz4frame.h index 75f1fd91..742c2528 100644 --- a/C/lz4/lz4frame.h +++ b/C/lz4/lz4frame.h @@ -32,11 +32,14 @@ - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c */ -/* LZ4F is a stand-alone API to create LZ4-compressed frames - * conformant with specification v1.6.1. - * It also offers streaming capabilities. +/* LZ4F is a stand-alone API able to create and decode LZ4 frames + * conformant with specification v1.6.1 in doc/lz4_Frame_format.md . + * Generated frames are compatible with `lz4` CLI. + * + * LZ4F also offers streaming capabilities. + * * lz4.h is not required when using lz4frame.h, - * except to get constant such as LZ4_VERSION_NUMBER. + * except to extract common constant such as LZ4_VERSION_NUMBER. * */ #ifndef LZ4F_H_09782039843 @@ -173,7 +176,7 @@ typedef struct { LZ4F_blockChecksum_t blockChecksumFlag; /* 1: each block followed by a checksum of block's compressed data; 0: disabled (default) */ } LZ4F_frameInfo_t; -#define LZ4F_INIT_FRAMEINFO { 0, 0, 0, 0, 0, 0, 0 } /* v1.8.3+ */ +#define LZ4F_INIT_FRAMEINFO { LZ4F_default, LZ4F_blockLinked, LZ4F_noContentChecksum, LZ4F_frame, 0ULL, 0U, LZ4F_noBlockChecksum } /* v1.8.3+ */ /*! LZ4F_preferences_t : * makes it possible to supply advanced compression instructions to streaming interface. @@ -188,14 +191,14 @@ typedef struct { unsigned reserved[3]; /* must be zero for forward compatibility */ } LZ4F_preferences_t; -#define LZ4F_INIT_PREFERENCES { LZ4F_INIT_FRAMEINFO, 0, 0, 0, { 0, 0, 0 } } /* v1.8.3+ */ +#define LZ4F_INIT_PREFERENCES { LZ4F_INIT_FRAMEINFO, 0, 0u, 0u, { 0u, 0u, 0u } } /* v1.8.3+ */ /*-********************************* * Simple compression function ***********************************/ -LZ4FLIB_API int LZ4F_compressionLevel_max(void); +LZ4FLIB_API int LZ4F_compressionLevel_max(void); /* v1.8.0+ */ /*! LZ4F_compressFrameBound() : * Returns the maximum possible compressed size with LZ4F_compressFrame() given srcSize and preferences. @@ -247,7 +250,9 @@ LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx); /*---- Compression ----*/ -#define LZ4F_HEADER_SIZE_MAX 19 /* LZ4 Frame header size can vary from 7 to 19 bytes */ +#define LZ4F_HEADER_SIZE_MIN 7 /* LZ4 Frame header size can vary, depending on selected paramaters */ +#define LZ4F_HEADER_SIZE_MAX 19 + /*! LZ4F_compressBegin() : * will write the frame header into dstBuffer. * dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes. @@ -260,15 +265,19 @@ LZ4FLIB_API size_t LZ4F_compressBegin(LZ4F_cctx* cctx, const LZ4F_preferences_t* prefsPtr); /*! LZ4F_compressBound() : - * Provides minimum dstCapacity required to guarantee compression success - * given a srcSize and preferences, covering worst case scenario. + * Provides minimum dstCapacity required to guarantee success of + * LZ4F_compressUpdate(), given a srcSize and preferences, for a worst case scenario. + * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() instead. + * Note that the result is only valid for a single invocation of LZ4F_compressUpdate(). + * When invoking LZ4F_compressUpdate() multiple times, + * if the output buffer is gradually filled up instead of emptied and re-used from its start, + * one must check if there is enough remaining capacity before each invocation, using LZ4F_compressBound(). + * @return is always the same for a srcSize and prefsPtr. * prefsPtr is optional : when NULL is provided, preferences will be set to cover worst case scenario. - * Estimation is valid for either LZ4F_compressUpdate(), LZ4F_flush() or LZ4F_compressEnd(), - * Estimation includes the possibility that internal buffer might already be filled by up to (blockSize-1) bytes. - * It also includes frame footer (ending + checksum), which would have to be generated by LZ4F_compressEnd(). - * Estimation doesn't include frame header, as it was already generated by LZ4F_compressBegin(). - * Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers. - * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations. + * tech details : + * @return includes the possibility that internal buffer might already be filled by up to (blockSize-1) bytes. + * It also includes frame footer (ending + checksum), since it might be generated by LZ4F_compressEnd(). + * @return doesn't include frame header, as it was already generated by LZ4F_compressBegin(). */ LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr); @@ -295,6 +304,7 @@ LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, * `cOptPtr` is optional : it's possible to provide NULL, all options will be set to default. * @return : nb of bytes written into dstBuffer (can be zero, when there is no data stored within cctx) * or an error code if it fails (which can be tested using LZ4F_isError()) + * Note : LZ4F_flush() is guaranteed to be successful when dstCapacity >= LZ4F_compressBound(0, prefsPtr). */ LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, @@ -307,6 +317,7 @@ LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx, * `cOptPtr` is optional : NULL can be provided, in which case all options will be set to default. * @return : nb of bytes written into dstBuffer, necessarily >= 4 (endMark), * or an error code if it fails (which can be tested using LZ4F_isError()) + * Note : LZ4F_compressEnd() is guaranteed to be successful when dstCapacity >= LZ4F_compressBound(0, prefsPtr). * A successful call to LZ4F_compressEnd() makes `cctx` available again for another compression task. */ LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx, @@ -345,23 +356,58 @@ LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx); * Streaming decompression functions *************************************/ +#define LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH 5 + +/*! LZ4F_headerSize() : v1.9.0+ + * Provide the header size of a frame starting at `src`. + * `srcSize` must be >= LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH, + * which is enough to decode the header length. + * @return : size of frame header + * or an error code, which can be tested using LZ4F_isError() + * note : Frame header size is variable, but is guaranteed to be + * >= LZ4F_HEADER_SIZE_MIN bytes, and <= LZ4F_HEADER_SIZE_MAX bytes. + */ +size_t LZ4F_headerSize(const void* src, size_t srcSize); + /*! LZ4F_getFrameInfo() : * This function extracts frame parameters (max blockSize, dictID, etc.). - * Its usage is optional. - * Extracted information is typically useful for allocation and dictionary. - * This function works in 2 situations : - * - At the beginning of a new frame, in which case - * it will decode information from `srcBuffer`, starting the decoding process. - * Input size must be large enough to successfully decode the entire frame header. - * Frame header size is variable, but is guaranteed to be <= LZ4F_HEADER_SIZE_MAX bytes. - * It's allowed to provide more input data than this minimum. - * - After decoding has been started. - * In which case, no input is read, frame parameters are extracted from dctx. - * - If decoding has barely started, but not yet extracted information from header, + * Its usage is optional: user can call LZ4F_decompress() directly. + * + * Extracted information will fill an existing LZ4F_frameInfo_t structure. + * This can be useful for allocation and dictionary identification purposes. + * + * LZ4F_getFrameInfo() can work in the following situations : + * + * 1) At the beginning of a new frame, before any invocation of LZ4F_decompress(). + * It will decode header from `srcBuffer`, + * consuming the header and starting the decoding process. + * + * Input size must be large enough to contain the full frame header. + * Frame header size can be known beforehand by LZ4F_headerSize(). + * Frame header size is variable, but is guaranteed to be >= LZ4F_HEADER_SIZE_MIN bytes, + * and not more than <= LZ4F_HEADER_SIZE_MAX bytes. + * Hence, blindly providing LZ4F_HEADER_SIZE_MAX bytes or more will always work. + * It's allowed to provide more input data than the header size, + * LZ4F_getFrameInfo() will only consume the header. + * + * If input size is not large enough, + * aka if it's smaller than header size, + * function will fail and return an error code. + * + * 2) After decoding has been started, + * it's possible to invoke LZ4F_getFrameInfo() anytime + * to extract already decoded frame parameters stored within dctx. + * + * Note that, if decoding has barely started, + * and not yet read enough information to decode the header, * LZ4F_getFrameInfo() will fail. - * The number of bytes consumed from srcBuffer will be updated within *srcSizePtr (necessarily <= original value). - * Decompression must resume from (srcBuffer + *srcSizePtr). - * @return : an hint about how many srcSize bytes LZ4F_decompress() expects for next call, + * + * The number of bytes consumed from srcBuffer will be updated in *srcSizePtr (necessarily <= original value). + * LZ4F_getFrameInfo() only consumes bytes when decoding has not yet started, + * and when decoding the header has been successful. + * Decompression must then resume from (srcBuffer + *srcSizePtr). + * + * @return : a hint about how many srcSize bytes LZ4F_decompress() expects for next call, * or an error code which can be tested using LZ4F_isError(). * note 1 : in case of error, dctx is not modified. Decoding operation can resume from beginning safely. * note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure. @@ -427,15 +473,15 @@ LZ4FLIB_API void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx); /* always su extern "C" { #endif -/* These declarations are not stable and may change in the future. They are - * therefore only safe to depend on when the caller is statically linked - * against the library. To access their declarations, define - * LZ4F_STATIC_LINKING_ONLY. +/* These declarations are not stable and may change in the future. + * They are therefore only safe to depend on + * when the caller is statically linked against the library. + * To access their declarations, define LZ4F_STATIC_LINKING_ONLY. * - * There is a further protection mechanism where these symbols aren't published - * into shared/dynamic libraries. You can override this behavior and force - * them to be published by defining LZ4F_PUBLISH_STATIC_FUNCTIONS. Use at - * your own risk. + * By default, these symbols aren't published into shared/dynamic libraries. + * You can override this behavior and force them to be published + * by defining LZ4F_PUBLISH_STATIC_FUNCTIONS. + * Use at your own risk. */ #ifdef LZ4F_PUBLISH_STATIC_FUNCTIONS #define LZ4FLIB_STATIC_API LZ4FLIB_API @@ -471,19 +517,38 @@ extern "C" { #define LZ4F_GENERATE_ENUM(ENUM) LZ4F_##ENUM, /* enum list is exposed, to handle specific errors */ -typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) } LZ4F_errorCodes; +typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) + _LZ4F_dummy_error_enum_for_c89_never_used } LZ4F_errorCodes; LZ4FLIB_STATIC_API LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult); - +LZ4FLIB_STATIC_API size_t LZ4F_getBlockSize(unsigned); /********************************** * Bulk processing dictionary API *********************************/ + +/* A Dictionary is useful for the compression of small messages (KB range). + * It dramatically improves compression efficiency. + * + * LZ4 can ingest any input as dictionary, though only the last 64 KB are useful. + * Best results are generally achieved by using Zstandard's Dictionary Builder + * to generate a high-quality dictionary from a set of samples. + * + * Loading a dictionary has a cost, since it involves construction of tables. + * The Bulk processing dictionary API makes it possible to share this cost + * over an arbitrary number of compression jobs, even concurrently, + * markedly improving compression latency for these cases. + * + * The same dictionary will have to be used on the decompression side + * for decoding to be successful. + * To help identify the correct dictionary at decoding stage, + * the frame header allows optional embedding of a dictID field. + */ typedef struct LZ4F_CDict_s LZ4F_CDict; /*! LZ4_createCDict() : - * When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once. + * When compressing multiple messages / blocks using the same dictionary, it's recommended to load it just once. * LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay. * LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only. * `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict */ diff --git a/C/lz4/lz4hc.c b/C/lz4/lz4hc.c index e913ee7b..936f7396 100644 --- a/C/lz4/lz4hc.c +++ b/C/lz4/lz4hc.c @@ -61,10 +61,15 @@ # pragma clang diagnostic ignored "-Wunused-function" #endif -#define LZ4_COMMONDEFS_ONLY -#include "lz4.c" /* LZ4_count, constants, mem */ +/*=== Enums ===*/ +typedef enum { noDictCtx, usingDictCtxHc } dictCtx_directive; +#define LZ4_COMMONDEFS_ONLY +#ifndef LZ4_SRC_INCLUDED +#include "lz4.c" /* LZ4_count, constants, mem */ +#endif + /*=== Constants ===*/ #define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH) #define LZ4_OPT_NUM (1<<12) @@ -76,12 +81,11 @@ #define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-LZ4HC_HASH_LOG)) #define DELTANEXTMAXD(p) chainTable[(p) & LZ4HC_MAXD_MASK] /* flexible, LZ4HC_MAXD dependent */ #define DELTANEXTU16(table, pos) table[(U16)(pos)] /* faster */ +/* Make fields passed to, and updated by LZ4HC_encodeSequence explicit */ +#define UPDATABLE(ip, op, anchor) &ip, &op, &anchor static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); } -/*=== Enums ===*/ -typedef enum { noDictCtx, usingDictCtx } dictCtx_directive; - /************************************** * HC Compression @@ -92,9 +96,9 @@ static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4) MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); } -static void LZ4HC_init (LZ4HC_CCtx_internal* hc4, const BYTE* start) +static void LZ4HC_init_internal (LZ4HC_CCtx_internal* hc4, const BYTE* start) { - uptrval startingOffset = hc4->end - hc4->base; + uptrval startingOffset = (uptrval)(hc4->end - hc4->base); if (startingOffset > 1 GB) { LZ4HC_clearTables(hc4); startingOffset = 0; @@ -121,7 +125,7 @@ LZ4_FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip) while (idx < target) { U32 const h = LZ4HC_hashPtr(base+idx); size_t delta = idx - hashTable[h]; - if (delta>MAX_DISTANCE) delta = MAX_DISTANCE; + if (delta>LZ4_DISTANCE_MAX) delta = LZ4_DISTANCE_MAX; DELTANEXTU16(chainTable, idx) = (U16)delta; hashTable[h] = idx; idx++; @@ -224,14 +228,13 @@ LZ4HC_InsertAndGetWiderMatch ( const U32 dictLimit = hc4->dictLimit; const BYTE* const lowPrefixPtr = base + dictLimit; const U32 ipIndex = (U32)(ip - base); - const U32 lowestMatchIndex = (hc4->lowLimit + 64 KB > ipIndex) ? hc4->lowLimit : ipIndex - MAX_DISTANCE; + const U32 lowestMatchIndex = (hc4->lowLimit + 64 KB > ipIndex) ? hc4->lowLimit : ipIndex - LZ4_DISTANCE_MAX; const BYTE* const dictBase = hc4->dictBase; int const lookBackLength = (int)(ip-iLowLimit); int nbAttempts = maxNbAttempts; - int matchChainPos = 0; + U32 matchChainPos = 0; U32 const pattern = LZ4_read32(ip); U32 matchIndex; - U32 dictMatchIndex; repeat_state_e repeat = rep_untested; size_t srcPatternLength = 0; @@ -256,7 +259,7 @@ LZ4HC_InsertAndGetWiderMatch ( if (LZ4_read16(iLowLimit + longest - 1) == LZ4_read16(matchPtr - lookBackLength + longest - 1)) { if (LZ4_read32(matchPtr) == pattern) { int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr) : 0; - matchLength = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); + matchLength = MINMATCH + (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); matchLength -= back; if (matchLength > longest) { longest = matchLength; @@ -270,7 +273,7 @@ LZ4HC_InsertAndGetWiderMatch ( int back = 0; const BYTE* vLimit = ip + (dictLimit - matchIndex); if (vLimit > iHighLimit) vLimit = iHighLimit; - matchLength = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; + matchLength = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; if ((ip+matchLength == vLimit) && (vLimit < iHighLimit)) matchLength += LZ4_count(ip+matchLength, lowPrefixPtr, iHighLimit); back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0; @@ -283,14 +286,14 @@ LZ4HC_InsertAndGetWiderMatch ( if (chainSwap && matchLength==longest) { /* better match => select a better chain */ assert(lookBackLength==0); /* search forward only */ - if (matchIndex + longest <= ipIndex) { + if (matchIndex + (U32)longest <= ipIndex) { U32 distanceToNextMatch = 1; int pos; for (pos = 0; pos <= longest - MINMATCH; pos++) { - U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + pos); + U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + (U32)pos); if (candidateDist > distanceToNextMatch) { distanceToNextMatch = candidateDist; - matchChainPos = pos; + matchChainPos = (U32)pos; } } if (distanceToNextMatch > 1) { if (distanceToNextMatch > matchIndex) break; /* avoid overflow */ @@ -315,7 +318,7 @@ LZ4HC_InsertAndGetWiderMatch ( const BYTE* const matchPtr = base + matchCandidateIdx; if (LZ4_read32(matchPtr) == pattern) { /* good candidate */ size_t const forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern); - const BYTE* const lowestMatchPtr = (lowPrefixPtr + MAX_DISTANCE >= ip) ? lowPrefixPtr : ip - MAX_DISTANCE; + const BYTE* const lowestMatchPtr = (lowPrefixPtr + LZ4_DISTANCE_MAX >= ip) ? lowPrefixPtr : ip - LZ4_DISTANCE_MAX; size_t const backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern); size_t const currentSegmentLength = backLength + forwardPatternLength; @@ -328,7 +331,7 @@ LZ4HC_InsertAndGetWiderMatch ( size_t const maxML = MIN(currentSegmentLength, srcPatternLength); if ((size_t)longest < maxML) { assert(base + matchIndex < ip); - if (ip - (base+matchIndex) > MAX_DISTANCE) break; + if (ip - (base+matchIndex) > LZ4_DISTANCE_MAX) break; assert(maxML < 2 GB); longest = (int)maxML; *matchpos = base + matchIndex; /* virtual pos, relative to ip, to retrieve offset */ @@ -343,16 +346,18 @@ LZ4HC_InsertAndGetWiderMatch ( } } /* PA optimization */ /* follow current chain */ - matchIndex -= DELTANEXTU16(chainTable, matchIndex+matchChainPos); + matchIndex -= DELTANEXTU16(chainTable, matchIndex + matchChainPos); } /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */ - if (dict == usingDictCtx && nbAttempts && ipIndex - lowestMatchIndex < MAX_DISTANCE) { - size_t const dictEndOffset = dictCtx->end - dictCtx->base; + if ( dict == usingDictCtxHc + && nbAttempts + && ipIndex - lowestMatchIndex < LZ4_DISTANCE_MAX) { + size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->base); + U32 dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)]; assert(dictEndOffset <= 1 GB); - dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)]; matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset; - while (ipIndex - matchIndex <= MAX_DISTANCE && nbAttempts--) { + while (ipIndex - matchIndex <= LZ4_DISTANCE_MAX && nbAttempts--) { const BYTE* const matchPtr = dictCtx->base + dictMatchIndex; if (LZ4_read32(matchPtr) == pattern) { @@ -360,22 +365,19 @@ LZ4HC_InsertAndGetWiderMatch ( int back = 0; const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex); if (vLimit > iHighLimit) vLimit = iHighLimit; - mlt = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; + mlt = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH; back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->base + dictCtx->dictLimit) : 0; mlt -= back; if (mlt > longest) { longest = mlt; *matchpos = base + matchIndex + back; *startpos = ip + back; - } - } + } } { U32 const nextOffset = DELTANEXTU16(dictCtx->chainTable, dictMatchIndex); dictMatchIndex -= nextOffset; matchIndex -= nextOffset; - } - } - } + } } } return longest; } @@ -395,14 +397,6 @@ int LZ4HC_InsertAndFindBestMatch(LZ4HC_CCtx_internal* const hc4, /* Index tabl return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts, patternAnalysis, 0 /*chainSwap*/, dict, favorCompressionRatio); } - - -typedef enum { - noLimit = 0, - limitedOutput = 1, - limitedDestSize = 2, -} limitedOutput_directive; - /* LZ4HC_encodeSequence() : * @return : 0 if ok, * 1 if buffer issue detected */ @@ -437,7 +431,7 @@ LZ4_FORCE_INLINE int LZ4HC_encodeSequence ( /* Encode Literal length */ length = (size_t)(*ip - *anchor); - if ((limit) && ((*op + (length >> 8) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1; /* Check output limit */ + if ((limit) && ((*op + (length / 255) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1; /* Check output limit */ if (length >= RUN_MASK) { size_t len = length - RUN_MASK; *token = (RUN_MASK << ML_BITS); @@ -448,17 +442,17 @@ LZ4_FORCE_INLINE int LZ4HC_encodeSequence ( } /* Copy Literals */ - LZ4_wildCopy(*op, *anchor, (*op) + length); + LZ4_wildCopy8(*op, *anchor, (*op) + length); *op += length; /* Encode Offset */ - assert( (*ip - match) <= MAX_DISTANCE ); /* note : consider providing offset as a value, rather than as a pointer difference */ + assert( (*ip - match) <= LZ4_DISTANCE_MAX ); /* note : consider providing offset as a value, rather than as a pointer difference */ LZ4_writeLE16(*op, (U16)(*ip-match)); *op += 2; /* Encode MatchLength */ assert(matchLength >= MINMATCH); - length = (size_t)(matchLength - MINMATCH); - if ((limit) && (*op + (length >> 8) + (1 + LASTLITERALS) > oend)) return 1; /* Check output limit */ + length = (size_t)matchLength - MINMATCH; + if ((limit) && (*op + (length / 255) + (1 + LASTLITERALS) > oend)) return 1; /* Check output limit */ if (length >= ML_MASK) { *token += ML_MASK; length -= ML_MASK; @@ -511,12 +505,12 @@ LZ4_FORCE_INLINE int LZ4HC_compress_hashChain ( /* init */ *srcSizePtr = 0; - if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ + if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */ /* Main Loop */ while (ip <= mflimit) { - ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict); + ml = LZ4HC_InsertAndFindBestMatch(ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict); if (ml encode ML1 */ optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; continue; } @@ -581,10 +575,10 @@ _Search3: if (start2 < ip+ml) ml = (int)(start2 - ip); /* Now, encode 2 sequences */ optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; ip = start2; optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml2, ref2, limit, oend)) goto _dest_overflow; continue; } @@ -603,7 +597,7 @@ _Search3: } optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; ip = start3; ref = ref3; ml = ml3; @@ -641,7 +635,7 @@ _Search3: } } optr = op; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; + if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow; /* ML2 becomes ML1 */ ip = start2; ref = ref2; ml = ml2; @@ -658,7 +652,7 @@ _last_literals: { size_t lastRunSize = (size_t)(iend - anchor); /* literals */ size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255; size_t const totalSize = 1 + litLength + lastRunSize; - if (limit == limitedDestSize) oend += LASTLITERALS; /* restore correct value */ + if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */ if (limit && (op + totalSize > oend)) { if (limit == limitedOutput) return 0; /* Check output limit */ /* adapt lastRunSize to fill 'dest' */ @@ -685,7 +679,7 @@ _last_literals: return (int) (((char*)op)-dest); _dest_overflow: - if (limit == limitedDestSize) { + if (limit == fillOutput) { op = optr; /* restore correct out pointer */ goto _last_literals; } @@ -735,56 +729,64 @@ LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal ( { lz4opt,16384,LZ4_OPT_NUM }, /* 12==LZ4HC_CLEVEL_MAX */ }; - DEBUGLOG(4, "LZ4HC_compress_generic(%p, %p, %d)", ctx, src, *srcSizePtr); + DEBUGLOG(4, "LZ4HC_compress_generic(ctx=%p, src=%p, srcSize=%d)", ctx, src, *srcSizePtr); - if (limit == limitedDestSize && dstCapacity < 1) return 0; /* Impossible to store anything */ - if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */ + if (limit == fillOutput && dstCapacity < 1) return 0; /* Impossible to store anything */ + if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */ ctx->end += *srcSizePtr; if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe something to review */ cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel); { cParams_t const cParam = clTable[cLevel]; HCfavor_e const favor = ctx->favorDecSpeed ? favorDecompressionSpeed : favorCompressionRatio; - if (cParam.strat == lz4hc) - return LZ4HC_compress_hashChain(ctx, + int result; + + if (cParam.strat == lz4hc) { + result = LZ4HC_compress_hashChain(ctx, src, dst, srcSizePtr, dstCapacity, cParam.nbSearches, limit, dict); - assert(cParam.strat == lz4opt); - return LZ4HC_compress_optimal(ctx, - src, dst, srcSizePtr, dstCapacity, - cParam.nbSearches, cParam.targetLength, limit, - cLevel == LZ4HC_CLEVEL_MAX, /* ultra mode */ - dict, favor); + } else { + assert(cParam.strat == lz4opt); + result = LZ4HC_compress_optimal(ctx, + src, dst, srcSizePtr, dstCapacity, + (int)cParam.nbSearches, cParam.targetLength, limit, + cLevel == LZ4HC_CLEVEL_MAX, /* ultra mode */ + dict, favor); + } + if (result <= 0) ctx->dirty = 1; + return result; } } static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock); -static int LZ4HC_compress_generic_noDictCtx ( - LZ4HC_CCtx_internal* const ctx, - const char* const src, - char* const dst, - int* const srcSizePtr, - int const dstCapacity, - int cLevel, - limitedOutput_directive limit - ) +static int +LZ4HC_compress_generic_noDictCtx ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) { assert(ctx->dictCtx == NULL); return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, noDictCtx); } -static int LZ4HC_compress_generic_dictCtx ( - LZ4HC_CCtx_internal* const ctx, - const char* const src, - char* const dst, - int* const srcSizePtr, - int const dstCapacity, - int cLevel, - limitedOutput_directive limit - ) +static int +LZ4HC_compress_generic_dictCtx ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) { - const size_t position = ctx->end - ctx->base - ctx->lowLimit; + const size_t position = (size_t)(ctx->end - ctx->base) - ctx->lowLimit; assert(ctx->dictCtx != NULL); if (position >= 64 KB) { ctx->dictCtx = NULL; @@ -795,19 +797,20 @@ static int LZ4HC_compress_generic_dictCtx ( ctx->compressionLevel = (short)cLevel; return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); } else { - return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtx); + return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtxHc); } } -static int LZ4HC_compress_generic ( - LZ4HC_CCtx_internal* const ctx, - const char* const src, - char* const dst, - int* const srcSizePtr, - int const dstCapacity, - int cLevel, - limitedOutput_directive limit - ) +static int +LZ4HC_compress_generic ( + LZ4HC_CCtx_internal* const ctx, + const char* const src, + char* const dst, + int* const srcSizePtr, + int const dstCapacity, + int cLevel, + limitedOutput_directive limit + ) { if (ctx->dictCtx == NULL) { return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); @@ -817,24 +820,41 @@ static int LZ4HC_compress_generic ( } -int LZ4_sizeofStateHC(void) { return sizeof(LZ4_streamHC_t); } +int LZ4_sizeofStateHC(void) { return (int)sizeof(LZ4_streamHC_t); } +#ifndef _MSC_VER /* for some reason, Visual fails the aligment test on 32-bit x86 : + * it reports an aligment of 8-bytes, + * while actually aligning LZ4_streamHC_t on 4 bytes. */ +static size_t LZ4_streamHC_t_alignment(void) +{ + struct { char c; LZ4_streamHC_t t; } t_a; + return sizeof(t_a) - sizeof(t_a.t); +} +#endif + +/* state is presumed correctly initialized, + * in which case its size and alignment have already been validate */ int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel) { LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse; +#ifndef _MSC_VER /* for some reason, Visual fails the aligment test on 32-bit x86 : + * it reports an aligment of 8-bytes, + * while actually aligning LZ4_streamHC_t on 4 bytes. */ + assert(((size_t)state & (LZ4_streamHC_t_alignment() - 1)) == 0); /* check alignment */ +#endif if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */ LZ4_resetStreamHC_fast((LZ4_streamHC_t*)state, compressionLevel); - LZ4HC_init (ctx, (const BYTE*)src); + LZ4HC_init_internal (ctx, (const BYTE*)src); if (dstCapacity < LZ4_compressBound(srcSize)) return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput); else - return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, noLimit); + return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, notLimited); } int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel) { - if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */ - LZ4_resetStreamHC ((LZ4_streamHC_t*)state, compressionLevel); + LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx)); + if (ctx==NULL) return 0; /* init failure */ return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel); } @@ -848,19 +868,19 @@ int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, in #endif int const cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, dstCapacity, compressionLevel); #if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1 - free(statePtr); + FREEMEM(statePtr); #endif return cSize; } -/* LZ4_compress_HC_destSize() : - * only compatible with regular HC parser */ -int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel) +/* state is presumed sized correctly (>= sizeof(LZ4_streamHC_t)) */ +int LZ4_compress_HC_destSize(void* state, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel) { - LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse; - LZ4_resetStreamHC((LZ4_streamHC_t*)LZ4HC_Data, cLevel); - LZ4HC_init(ctx, (const BYTE*) source); - return LZ4HC_compress_generic(ctx, source, dest, sourceSizePtr, targetDestSize, cLevel, limitedDestSize); + LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx)); + if (ctx==NULL) return 0; /* init failure */ + LZ4HC_init_internal(&ctx->internal_donotuse, (const BYTE*) source); + LZ4_setCompressionLevel(ctx, cLevel); + return LZ4HC_compress_generic(&ctx->internal_donotuse, source, dest, sourceSizePtr, targetDestSize, cLevel, fillOutput); } @@ -869,44 +889,70 @@ int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, i * Streaming Functions **************************************/ /* allocation */ -LZ4_streamHC_t* LZ4_createStreamHC(void) { +LZ4_streamHC_t* LZ4_createStreamHC(void) +{ LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t)); if (LZ4_streamHCPtr==NULL) return NULL; - LZ4_resetStreamHC(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT); + LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); /* full initialization, malloc'ed buffer can be full of garbage */ return LZ4_streamHCPtr; } -int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) { +int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) +{ DEBUGLOG(4, "LZ4_freeStreamHC(%p)", LZ4_streamHCPtr); if (!LZ4_streamHCPtr) return 0; /* support free on NULL */ - free(LZ4_streamHCPtr); + FREEMEM(LZ4_streamHCPtr); return 0; } -/* initialization */ -void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) +LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size) { - LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= sizeof(size_t) * LZ4_STREAMHCSIZE_SIZET); /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */ - DEBUGLOG(4, "LZ4_resetStreamHC(%p, %d)", LZ4_streamHCPtr, compressionLevel); + LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)buffer; + if (buffer == NULL) return NULL; + if (size < sizeof(LZ4_streamHC_t)) return NULL; +#ifndef _MSC_VER /* for some reason, Visual fails the aligment test on 32-bit x86 : + * it reports an aligment of 8-bytes, + * while actually aligning LZ4_streamHC_t on 4 bytes. */ + if (((size_t)buffer) & (LZ4_streamHC_t_alignment() - 1)) return NULL; /* alignment check */ +#endif + /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */ + LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= LZ4_STREAMHCSIZE); + DEBUGLOG(4, "LZ4_initStreamHC(%p, %u)", LZ4_streamHCPtr, (unsigned)size); + /* end-base will trigger a clearTable on starting compression */ LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1; LZ4_streamHCPtr->internal_donotuse.base = NULL; LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = 0; + LZ4_streamHCPtr->internal_donotuse.dirty = 0; + LZ4_setCompressionLevel(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT); + return LZ4_streamHCPtr; +} + +/* just a stub */ +void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) +{ + LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel); } void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) { DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel); - LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base; - LZ4_streamHCPtr->internal_donotuse.base = NULL; - LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; + if (LZ4_streamHCPtr->internal_donotuse.dirty) { + LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); + } else { + /* preserve end - base : can trigger clearTable's threshold */ + LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base; + LZ4_streamHCPtr->internal_donotuse.base = NULL; + LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL; + } LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel); } void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel) { + DEBUGLOG(5, "LZ4_setCompressionLevel(%p, %d)", LZ4_streamHCPtr, compressionLevel); if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT; if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX; LZ4_streamHCPtr->internal_donotuse.compressionLevel = (short)compressionLevel; @@ -917,16 +963,24 @@ void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor) LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = (favor!=0); } -int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize) +/* LZ4_loadDictHC() : + * LZ4_streamHCPtr is presumed properly initialized */ +int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, + const char* dictionary, int dictSize) { LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse; DEBUGLOG(4, "LZ4_loadDictHC(%p, %p, %d)", LZ4_streamHCPtr, dictionary, dictSize); + assert(LZ4_streamHCPtr != NULL); if (dictSize > 64 KB) { - dictionary += dictSize - 64 KB; + dictionary += (size_t)dictSize - 64 KB; dictSize = 64 KB; } - LZ4_resetStreamHC(LZ4_streamHCPtr, ctxPtr->compressionLevel); - LZ4HC_init (ctxPtr, (const BYTE*)dictionary); + /* need a full initialization, there are bad side-effects when using resetFast() */ + { int const cLevel = ctxPtr->compressionLevel; + LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr)); + LZ4_setCompressionLevel(LZ4_streamHCPtr, cLevel); + } + LZ4HC_init_internal (ctxPtr, (const BYTE*)dictionary); ctxPtr->end = (const BYTE*)dictionary + dictSize; if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3); return dictSize; @@ -959,9 +1013,11 @@ static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr, limitedOutput_directive limit) { LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse; - DEBUGLOG(4, "LZ4_compressHC_continue_generic(%p, %p, %d)", LZ4_streamHCPtr, src, *srcSizePtr); + DEBUGLOG(4, "LZ4_compressHC_continue_generic(ctx=%p, src=%p, srcSize=%d)", + LZ4_streamHCPtr, src, *srcSizePtr); + assert(ctxPtr != NULL); /* auto-init if forgotten */ - if (ctxPtr->base == NULL) LZ4HC_init (ctxPtr, (const BYTE*) src); + if (ctxPtr->base == NULL) LZ4HC_init_internal (ctxPtr, (const BYTE*) src); /* Check overflow */ if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 GB) { @@ -971,7 +1027,8 @@ static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr, } /* Check if blocks follow each other */ - if ((const BYTE*)src != ctxPtr->end) LZ4HC_setExternalDict(ctxPtr, (const BYTE*)src); + if ((const BYTE*)src != ctxPtr->end) + LZ4HC_setExternalDict(ctxPtr, (const BYTE*)src); /* Check overlapping input/dictionary space */ { const BYTE* sourceEnd = (const BYTE*) src + *srcSizePtr; @@ -992,12 +1049,12 @@ int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, if (dstCapacity < LZ4_compressBound(srcSize)) return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, limitedOutput); else - return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, noLimit); + return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, notLimited); } int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int* srcSizePtr, int targetDestSize) { - return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, limitedDestSize); + return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, fillOutput); } @@ -1016,19 +1073,21 @@ int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictS { U32 const endIndex = (U32)(streamPtr->end - streamPtr->base); streamPtr->end = (const BYTE*)safeBuffer + dictSize; streamPtr->base = streamPtr->end - endIndex; - streamPtr->dictLimit = endIndex - dictSize; - streamPtr->lowLimit = endIndex - dictSize; + streamPtr->dictLimit = endIndex - (U32)dictSize; + streamPtr->lowLimit = endIndex - (U32)dictSize; if (streamPtr->nextToUpdate < streamPtr->dictLimit) streamPtr->nextToUpdate = streamPtr->dictLimit; } return dictSize; } -/*********************************** +/*************************************************** * Deprecated Functions -***********************************/ +***************************************************/ + /* These functions currently generate deprecation warnings */ -/* Deprecated compression functions */ + +/* Wrappers for deprecated compression functions */ int LZ4_compressHC(const char* src, char* dst, int srcSize) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), 0); } int LZ4_compressHC_limitedOutput(const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC(src, dst, srcSize, maxDstSize, 0); } int LZ4_compressHC2(const char* src, char* dst, int srcSize, int cLevel) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), cLevel); } @@ -1044,25 +1103,26 @@ int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* ctx, const char* src, /* Deprecated streaming functions */ int LZ4_sizeofStreamStateHC(void) { return LZ4_STREAMHCSIZE; } +/* state is presumed correctly sized, aka >= sizeof(LZ4_streamHC_t) + * @return : 0 on success, !=0 if error */ int LZ4_resetStreamStateHC(void* state, char* inputBuffer) { - LZ4HC_CCtx_internal *ctx = &((LZ4_streamHC_t*)state)->internal_donotuse; - if ((((size_t)state) & (sizeof(void*)-1)) != 0) return 1; /* Error : pointer is not aligned for pointer (32 or 64 bits) */ - LZ4_resetStreamHC((LZ4_streamHC_t*)state, ((LZ4_streamHC_t*)state)->internal_donotuse.compressionLevel); - LZ4HC_init(ctx, (const BYTE*)inputBuffer); + LZ4_streamHC_t* const hc4 = LZ4_initStreamHC(state, sizeof(*hc4)); + if (hc4 == NULL) return 1; /* init failed */ + LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer); return 0; } void* LZ4_createHC (const char* inputBuffer) { - LZ4_streamHC_t* hc4 = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t)); + LZ4_streamHC_t* const hc4 = LZ4_createStreamHC(); if (hc4 == NULL) return NULL; /* not enough memory */ - LZ4_resetStreamHC(hc4, 0 /* compressionLevel */); - LZ4HC_init (&hc4->internal_donotuse, (const BYTE*)inputBuffer); + LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer); return hc4; } -int LZ4_freeHC (void* LZ4HC_Data) { +int LZ4_freeHC (void* LZ4HC_Data) +{ if (!LZ4HC_Data) return 0; /* support free on NULL */ FREEMEM(LZ4HC_Data); return 0; @@ -1070,7 +1130,7 @@ int LZ4_freeHC (void* LZ4HC_Data) { int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int cLevel) { - return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, 0, cLevel, noLimit); + return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, 0, cLevel, notLimited); } int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int dstCapacity, int cLevel) @@ -1089,7 +1149,7 @@ char* LZ4_slideInputBufferHC(void* LZ4HC_Data) /* ================================================ - * LZ4 Optimal parser (levels 10-12) + * LZ4 Optimal parser (levels [LZ4HC_CLEVEL_OPT_MIN - LZ4HC_CLEVEL_MAX]) * ===============================================*/ typedef struct { int price; @@ -1102,8 +1162,9 @@ typedef struct { LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen) { int price = litlen; + assert(litlen >= 0); if (litlen >= (int)RUN_MASK) - price += 1 + (litlen-RUN_MASK)/255; + price += 1 + ((litlen-(int)RUN_MASK) / 255); return price; } @@ -1112,11 +1173,13 @@ LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen) LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen) { int price = 1 + 2 ; /* token + 16-bit offset */ + assert(litlen >= 0); + assert(mlen >= MINMATCH); price += LZ4HC_literalsPrice(litlen); if (mlen >= (int)(ML_MASK+MINMATCH)) - price += 1 + (mlen-(ML_MASK+MINMATCH))/255; + price += 1 + ((mlen-(int)(ML_MASK+MINMATCH)) / 255); return price; } @@ -1175,9 +1238,9 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, BYTE* oend = op + dstCapacity; /* init */ - DEBUGLOG(5, "LZ4HC_compress_optimal"); + DEBUGLOG(5, "LZ4HC_compress_optimal(dst=%p, dstCapa=%u)", dst, (unsigned)dstCapacity); *srcSizePtr = 0; - if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ + if (limit == fillOutput) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1; /* Main Loop */ @@ -1195,7 +1258,7 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, int const firstML = firstMatch.len; const BYTE* const matchPos = ip - firstMatch.off; opSaved = op; - if ( LZ4HC_encodeSequence(&ip, &op, &anchor, firstML, matchPos, limit, oend) ) /* updates ip, op and anchor */ + if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), firstML, matchPos, limit, oend) ) /* updates ip, op and anchor */ goto _dest_overflow; continue; } @@ -1333,6 +1396,7 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, } } } /* for (cur = 1; cur <= last_match_pos; cur++) */ + assert(last_match_pos < LZ4_OPT_NUM + TRAILING_LITERALS); best_mlen = opt[last_match_pos].mlen; best_off = opt[last_match_pos].off; cur = last_match_pos - best_mlen; @@ -1365,9 +1429,9 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, if (ml == 1) { ip++; rPos++; continue; } /* literal; note: can end up with several literals, in which case, skip them */ rPos += ml; assert(ml >= MINMATCH); - assert((offset >= 1) && (offset <= MAX_DISTANCE)); + assert((offset >= 1) && (offset <= LZ4_DISTANCE_MAX)); opSaved = op; - if ( LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ip - offset, limit, oend) ) /* updates ip, op and anchor */ + if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ip - offset, limit, oend) ) /* updates ip, op and anchor */ goto _dest_overflow; } } } /* while (ip <= mflimit) */ @@ -1377,7 +1441,7 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, { size_t lastRunSize = (size_t)(iend - anchor); /* literals */ size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255; size_t const totalSize = 1 + litLength + lastRunSize; - if (limit == limitedDestSize) oend += LASTLITERALS; /* restore correct value */ + if (limit == fillOutput) oend += LASTLITERALS; /* restore correct value */ if (limit && (op + totalSize > oend)) { if (limit == limitedOutput) return 0; /* Check output limit */ /* adapt lastRunSize to fill 'dst' */ @@ -1404,7 +1468,7 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, return (int) ((char*)op-dst); _dest_overflow: - if (limit == limitedDestSize) { + if (limit == fillOutput) { op = opSaved; /* restore correct out pointer */ goto _last_literals; } diff --git a/C/lz4/lz4hc.h b/C/lz4/lz4hc.h index 970fa396..cdc6d895 100644 --- a/C/lz4/lz4hc.h +++ b/C/lz4/lz4hc.h @@ -54,7 +54,7 @@ extern "C" { * Block Compression **************************************/ /*! LZ4_compress_HC() : - * Compress data from `src` into `dst`, using the more powerful but slower "HC" algorithm. + * Compress data from `src` into `dst`, using the powerful but slower "HC" algorithm. * `dst` must be already allocated. * Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h") * Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h") @@ -77,7 +77,21 @@ LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dst * Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() should do properly). */ LZ4LIB_API int LZ4_sizeofStateHC(void); -LZ4LIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel); +LZ4LIB_API int LZ4_compress_HC_extStateHC(void* stateHC, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel); + + +/*! LZ4_compress_HC_destSize() : v1.9.0+ + * Will compress as much data as possible from `src` + * to fit into `targetDstSize` budget. + * Result is provided in 2 parts : + * @return : the number of bytes written into 'dst' (necessarily <= targetDstSize) + * or 0 if compression fails. + * `srcSizePtr` : on success, *srcSizePtr is updated to indicate how much bytes were read from `src` + */ +LZ4LIB_API int LZ4_compress_HC_destSize(void* stateHC, + const char* src, char* dst, + int* srcSizePtr, int targetDstSize, + int compressionLevel); /*-************************************ @@ -89,46 +103,92 @@ LZ4LIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* ds /*! LZ4_createStreamHC() and LZ4_freeStreamHC() : * These functions create and release memory for LZ4 HC streaming state. * Newly created states are automatically initialized. - * Existing states can be re-used several times, using LZ4_resetStreamHC(). - * These methods are API and ABI stable, they can be used in combination with a DLL. + * A same state can be used multiple times consecutively, + * starting with LZ4_resetStreamHC_fast() to start a new stream of blocks. */ LZ4LIB_API LZ4_streamHC_t* LZ4_createStreamHC(void); LZ4LIB_API int LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr); -LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel); +/* + These functions compress data in successive blocks of any size, + using previous blocks as dictionary, to improve compression ratio. + One key assumption is that previous blocks (up to 64 KB) remain read-accessible while compressing next blocks. + There is an exception for ring buffers, which can be smaller than 64 KB. + Ring-buffer scenario is automatically detected and handled within LZ4_compress_HC_continue(). + + Before starting compression, state must be allocated and properly initialized. + LZ4_createStreamHC() does both, though compression level is set to LZ4HC_CLEVEL_DEFAULT. + + Selecting the compression level can be done with LZ4_resetStreamHC_fast() (starts a new stream) + or LZ4_setCompressionLevel() (anytime, between blocks in the same stream) (experimental). + LZ4_resetStreamHC_fast() only works on states which have been properly initialized at least once, + which is automatically the case when state is created using LZ4_createStreamHC(). + + After reset, a first "fictional block" can be designated as initial dictionary, + using LZ4_loadDictHC() (Optional). + + Invoke LZ4_compress_HC_continue() to compress each successive block. + The number of blocks is unlimited. + Previous input blocks, including initial dictionary when present, + must remain accessible and unmodified during compression. + + It's allowed to update compression level anytime between blocks, + using LZ4_setCompressionLevel() (experimental). + + 'dst' buffer should be sized to handle worst case scenarios + (see LZ4_compressBound(), it ensures compression success). + In case of failure, the API does not guarantee recovery, + so the state _must_ be reset. + To ensure compression success + whenever `dst` buffer size cannot be made >= LZ4_compressBound(), + consider using LZ4_compress_HC_continue_destSize(). + + Whenever previous input blocks can't be preserved unmodified in-place during compression of next blocks, + it's possible to copy the last blocks into a more stable memory space, using LZ4_saveDictHC(). + Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer' (<= 64 KB) + + After completing a streaming compression, + it's possible to start a new stream of blocks, using the same LZ4_streamHC_t state, + just by resetting it, using LZ4_resetStreamHC_fast(). +*/ + +LZ4LIB_API void LZ4_resetStreamHC_fast(LZ4_streamHC_t* streamHCPtr, int compressionLevel); /* v1.9.0+ */ LZ4LIB_API int LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize); -LZ4LIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr, const char* src, char* dst, int srcSize, int maxDstSize); +LZ4LIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr, + const char* src, char* dst, + int srcSize, int maxDstSize); + +/*! LZ4_compress_HC_continue_destSize() : v1.9.0+ + * Similar to LZ4_compress_HC_continue(), + * but will read as much data as possible from `src` + * to fit into `targetDstSize` budget. + * Result is provided into 2 parts : + * @return : the number of bytes written into 'dst' (necessarily <= targetDstSize) + * or 0 if compression fails. + * `srcSizePtr` : on success, *srcSizePtr will be updated to indicate how much bytes were read from `src`. + * Note that this function may not consume the entire input. + */ +LZ4LIB_API int LZ4_compress_HC_continue_destSize(LZ4_streamHC_t* LZ4_streamHCPtr, + const char* src, char* dst, + int* srcSizePtr, int targetDstSize); LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, int maxDictSize); -/* - These functions compress data in successive blocks of any size, using previous blocks as dictionary. - One key assumption is that previous blocks (up to 64 KB) remain read-accessible while compressing next blocks. - There is an exception for ring buffers, which can be smaller than 64 KB. - Ring buffers scenario is automatically detected and handled by LZ4_compress_HC_continue(). - - Before starting compression, state must be properly initialized, using LZ4_resetStreamHC(). - A first "fictional block" can then be designated as initial dictionary, using LZ4_loadDictHC() (Optional). - - Then, use LZ4_compress_HC_continue() to compress each successive block. - Previous memory blocks (including initial dictionary when present) must remain accessible and unmodified during compression. - 'dst' buffer should be sized to handle worst case scenarios (see LZ4_compressBound()), to ensure operation success. - Because in case of failure, the API does not guarantee context recovery, and context will have to be reset. - If `dst` buffer budget cannot be >= LZ4_compressBound(), consider using LZ4_compress_HC_continue_destSize() instead. - - If, for any reason, previous data block can't be preserved unmodified in memory for next compression block, - you can save it to a more stable memory space, using LZ4_saveDictHC(). - Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer'. -*/ -/*-************************************************************** +/*^********************************************** + * !!!!!! STATIC LINKING ONLY !!!!!! + ***********************************************/ + +/*-****************************************************************** * PRIVATE DEFINITIONS : - * Do not use these definitions. - * They are exposed to allow static allocation of `LZ4_streamHC_t`. - * Using these definitions makes the code vulnerable to potential API break when upgrading LZ4 - ****************************************************************/ + * Do not use these definitions directly. + * They are merely exposed to allow static allocation of `LZ4_streamHC_t`. + * Declare an `LZ4_streamHC_t` directly, rather than any type below. + * Even then, only do so in the context of static linking, as definitions may change between versions. + ********************************************************************/ + #define LZ4HC_DICTIONARY_LOGSIZE 16 #define LZ4HC_MAXD (1<= LZ4HC_CLEVEL_OPT_MIN. */ -int LZ4_compress_HC_continue_destSize(LZ4_streamHC_t* LZ4_streamHCPtr, - const char* src, char* dst, - int* srcSizePtr, int targetDstSize); +LZ4LIB_STATIC_API void LZ4_favorDecompressionSpeed( + LZ4_streamHC_t* LZ4_streamHCPtr, int favor); -/*! LZ4_setCompressionLevel() : v1.8.0 (experimental) - * It's possible to change compression level between 2 invocations of LZ4_compress_HC_continue*() - */ -void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); - -/*! LZ4_favorDecompressionSpeed() : v1.8.2 (experimental) - * Parser will select decisions favoring decompression over compression ratio. - * Only work at highest compression settings (level >= LZ4HC_CLEVEL_OPT_MIN) - */ -void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor); - -/*! LZ4_resetStreamHC_fast() : +/*! LZ4_resetStreamHC_fast() : v1.9.0+ * When an LZ4_streamHC_t is known to be in a internally coherent state, * it can often be prepared for a new compression with almost no work, only * sometimes falling back to the full, expensive reset that is always required @@ -304,8 +372,14 @@ void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor); * - the stream was in an indeterminate state and was used in a compression * call that fully reset the state (LZ4_compress_HC_extStateHC()) and that * returned success + * + * Note: + * A stream that was last used in a compression call that returned an error + * may be passed to this function. However, it will be fully reset, which will + * clear any existing history and settings from the context. */ -void LZ4_resetStreamHC_fast(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); +LZ4LIB_STATIC_API void LZ4_resetStreamHC_fast( + LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); /*! LZ4_compress_HC_extStateHC_fastReset() : * A variant of LZ4_compress_HC_extStateHC(). @@ -318,7 +392,11 @@ void LZ4_resetStreamHC_fast(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLeve * LZ4_resetStreamHC_fast() while LZ4_compress_HC_extStateHC() starts with a * call to LZ4_resetStreamHC(). */ -int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel); +LZ4LIB_STATIC_API int LZ4_compress_HC_extStateHC_fastReset ( + void* state, + const char* src, char* dst, + int srcSize, int dstCapacity, + int compressionLevel); /*! LZ4_attach_HC_dictionary() : * This is an experimental API that allows for the efficient use of a @@ -345,7 +423,9 @@ int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* ds * stream (and source buffer) must remain in-place / accessible / unchanged * through the lifetime of the stream session. */ -LZ4LIB_API void LZ4_attach_HC_dictionary(LZ4_streamHC_t *working_stream, const LZ4_streamHC_t *dictionary_stream); +LZ4LIB_STATIC_API void LZ4_attach_HC_dictionary( + LZ4_streamHC_t *working_stream, + const LZ4_streamHC_t *dictionary_stream); #if defined (__cplusplus) } diff --git a/README.md b/README.md index 4426fe1e..d8506b12 100644 --- a/README.md +++ b/README.md @@ -21,7 +21,7 @@ You can install it in two ways: 2. [Brotli] v.1.0.7 is a generic-purpose lossless compression algorithm that compresses data using a combination of a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling, with a compression ratio comparable to the best currently available general-purpose compression methods. It is similar in speed with deflate but offers more dense compression. - Levels: 0..11 -3. [LZ4] v1.8.3 is lossless compression algorithm, providing compression speed at 400 MB/s per core (0.16 Bytes/cycle). It features an extremely fast decoder, with speed in multiple GB/s per core (0.71 Bytes/cycle). A high compression derivative, called LZ4_HC, is available, trading customizable CPU time for compression ratio. +3. [LZ4] v1.9.1 is lossless compression algorithm, providing compression speed at 400 MB/s per core (0.16 Bytes/cycle). It features an extremely fast decoder, with speed in multiple GB/s per core (0.71 Bytes/cycle). A high compression derivative, called LZ4_HC, is available, trading customizable CPU time for compression ratio. - Levels: 1..12 4. [LZ5] v1.5 is a modification of LZ4 which gives a better ratio at cost of slower compression and decompression. @@ -278,11 +278,11 @@ You find this project useful, maybe you consider a donation ;-) - [Brotli] Version 1.0.7 - [Fast LZMA2] Version 1.0.0 - [Lizard] Version 1.0 - - [LZ4] Version 1.8.3 + - [LZ4] Version 1.9.1 - [LZ5] Version 1.5 - [Zstandard] Version 1.4.0 -/TR 2019-04-26 +/TR 2019-05-04 ## Notes