diff options
Diffstat (limited to 'lib/lz4hc.h')
| -rw-r--r-- | lib/lz4hc.h | 253 |
1 files changed, 190 insertions, 63 deletions
diff --git a/lib/lz4hc.h b/lib/lz4hc.h index 1036fd0b..970fa396 100644 --- a/lib/lz4hc.h +++ b/lib/lz4hc.h @@ -1,7 +1,7 @@ /* LZ4 HC - High Compression Mode of LZ4 Header File - Copyright (C) 2011-2016, Yann Collet. + Copyright (C) 2011-2017, 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 @@ -39,14 +39,14 @@ extern "C" { #endif /* --- Dependency --- */ -/* note : lz4hc is not an independent module, it requires lz4.h/lz4.c for proper compilation */ +/* note : lz4hc requires lz4.h/lz4.c for compilation */ #include "lz4.h" /* stddef, LZ4LIB_API, LZ4_DEPRECATED */ /* --- Useful constants --- */ #define LZ4HC_CLEVEL_MIN 3 #define LZ4HC_CLEVEL_DEFAULT 9 -#define LZ4HC_CLEVEL_OPT_MIN 11 +#define LZ4HC_CLEVEL_OPT_MIN 10 #define LZ4HC_CLEVEL_MAX 12 @@ -54,12 +54,12 @@ 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 more 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") - * `compressionLevel` : Recommended values are between 4 and 9, although any value between 1 and LZ4HC_MAX_CLEVEL will work. - * Values >LZ4HC_MAX_CLEVEL behave the same as LZ4HC_MAX_CLEVEL. + * 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") + * `compressionLevel` : any value between 1 and LZ4HC_CLEVEL_MAX will work. + * Values > LZ4HC_CLEVEL_MAX behave the same as LZ4HC_CLEVEL_MAX. * @return : the number of bytes written into 'dst' * or 0 if compression fails. */ @@ -72,12 +72,12 @@ LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dst /*! LZ4_compress_HC_extStateHC() : - * Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`. + * Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`. * `state` size is provided by LZ4_sizeofStateHC(). - * Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() will do properly). + * Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() should do properly). */ -LZ4LIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel); 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); /*-************************************ @@ -87,10 +87,10 @@ LZ4LIB_API int LZ4_sizeofStateHC(void); typedef union LZ4_streamHC_u LZ4_streamHC_t; /* incomplete type (defined later) */ /*! 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. + * 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. */ LZ4LIB_API LZ4_streamHC_t* LZ4_createStreamHC(void); LZ4LIB_API int LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr); @@ -113,25 +113,23 @@ LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, in 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, using LZ4_compressBound(), to ensure operation success. + '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 blocks can't be preserved unmodified in memory during next compression block, - you must save it to a safer memory space, using LZ4_saveDictHC(). + 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 - **************************************/ -#define LZ4HC_DICTIONARY_LOGSIZE 17 + ****************************************************************/ +#define LZ4HC_DICTIONARY_LOGSIZE 16 #define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE) #define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1) @@ -143,41 +141,43 @@ LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, in #if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) #include <stdint.h> -typedef struct +typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal; +struct LZ4HC_CCtx_internal { uint32_t hashTable[LZ4HC_HASHTABLESIZE]; uint16_t chainTable[LZ4HC_MAXD]; - const uint8_t* end; /* next block here to continue on current prefix */ - const uint8_t* base; /* All index relative to this position */ - const uint8_t* dictBase; /* alternate base for extDict */ - uint8_t* inputBuffer; /* deprecated */ - uint32_t dictLimit; /* below that point, need extDict */ - uint32_t lowLimit; /* below that point, no more dict */ - uint32_t nextToUpdate; /* index from which to continue dictionary update */ - uint32_t searchNum; /* only for optimal parser */ - uint32_t compressionLevel; -} LZ4HC_CCtx_internal; + const uint8_t* end; /* next block here to continue on current prefix */ + const uint8_t* base; /* All index relative to this position */ + const uint8_t* dictBase; /* alternate base for extDict */ + uint32_t dictLimit; /* below that point, need extDict */ + uint32_t lowLimit; /* below that point, no more dict */ + uint32_t nextToUpdate; /* index from which to continue dictionary update */ + short compressionLevel; + short favorDecSpeed; + const LZ4HC_CCtx_internal* dictCtx; +}; #else -typedef struct +typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal; +struct LZ4HC_CCtx_internal { unsigned int hashTable[LZ4HC_HASHTABLESIZE]; - unsigned short chainTable[LZ4HC_MAXD]; + unsigned short chainTable[LZ4HC_MAXD]; const unsigned char* end; /* next block here to continue on current prefix */ const unsigned char* base; /* All index relative to this position */ const unsigned char* dictBase; /* alternate base for extDict */ - unsigned char* inputBuffer; /* deprecated */ unsigned int dictLimit; /* below that point, need extDict */ unsigned int lowLimit; /* below that point, no more dict */ unsigned int nextToUpdate; /* index from which to continue dictionary update */ - unsigned int searchNum; /* only for optimal parser */ - unsigned int compressionLevel; -} LZ4HC_CCtx_internal; + short compressionLevel; + short favorDecSpeed; + const LZ4HC_CCtx_internal* dictCtx; +}; #endif -#define LZ4_STREAMHCSIZE (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56) /* 393268 */ +#define LZ4_STREAMHCSIZE (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56) /* 262200 */ #define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t)) union LZ4_streamHC_u { size_t table[LZ4_STREAMHCSIZE_SIZET]; @@ -199,26 +199,32 @@ union LZ4_streamHC_u { /* see lz4.h LZ4_DISABLE_DEPRECATE_WARNINGS to turn off deprecation warnings */ /* deprecated compression functions */ -/* these functions will trigger warning messages in future releases */ -LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC (const char* source, char* dest, int inputSize); -LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize); -LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel); -LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); -LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize); -LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); -LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel); -LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); -LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize); -LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize); - -/* Deprecated Streaming functions using older model; should no longer be used */ -LZ4_DEPRECATED("use LZ4_createStreamHC() instead") void* LZ4_createHC (char* inputBuffer); -LZ4_DEPRECATED("use LZ4_saveDictHC() instead") char* LZ4_slideInputBufferHC (void* LZ4HC_Data); -LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") int LZ4_freeHC (void* LZ4HC_Data); -LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel); -LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); -LZ4_DEPRECATED("use LZ4_createStreamHC() instead") int LZ4_sizeofStreamStateHC(void); -LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") int LZ4_resetStreamStateHC(void* state, char* inputBuffer); +LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC (const char* source, char* dest, int inputSize); +LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize); +LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel); +LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); +LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize); +LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); +LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel); +LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); +LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize); +LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize); + +/* Obsolete streaming functions; degraded functionality; do not use! + * + * In order to perform streaming compression, these functions depended on data + * that is no longer tracked in the state. They have been preserved as well as + * possible: using them will still produce a correct output. However, use of + * LZ4_slideInputBufferHC() will truncate the history of the stream, rather + * than preserve a window-sized chunk of history. + */ +LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API void* LZ4_createHC (const char* inputBuffer); +LZ4_DEPRECATED("use LZ4_saveDictHC() instead") LZ4LIB_API char* LZ4_slideInputBufferHC (void* LZ4HC_Data); +LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") LZ4LIB_API int LZ4_freeHC (void* LZ4HC_Data); +LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel); +LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); +LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API int LZ4_sizeofStreamStateHC(void); +LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") LZ4LIB_API int LZ4_resetStreamStateHC(void* state, char* inputBuffer); #if defined (__cplusplus) @@ -226,3 +232,124 @@ LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") int LZ4_resetStreamStateHC( #endif #endif /* LZ4_HC_H_19834876238432 */ + + +/*-************************************************** + * !!!!! STATIC LINKING ONLY !!!!! + * Following definitions are considered experimental. + * They should not be linked from DLL, + * as there is no guarantee of API stability yet. + * Prototypes will be promoted to "stable" status + * after successfull usage in real-life scenarios. + ***************************************************/ +#ifdef LZ4_HC_STATIC_LINKING_ONLY /* protection macro */ +#ifndef LZ4_HC_SLO_098092834 +#define LZ4_HC_SLO_098092834 + +#if defined (__cplusplus) +extern "C" { +#endif + +/*! LZ4_compress_HC_destSize() : v1.8.0 (experimental) + * Will try to compress as much data from `src` as possible + * that can fit into `targetDstSize` budget. + * Result is provided in 2 parts : + * @return : the number of bytes written into 'dst' + * or 0 if compression fails. + * `srcSizePtr` : value will be updated to indicate how much bytes were read from `src` + */ +int LZ4_compress_HC_destSize(void* LZ4HC_Data, + const char* src, char* dst, + int* srcSizePtr, int targetDstSize, + int compressionLevel); + +/*! LZ4_compress_HC_continue_destSize() : v1.8.0 (experimental) + * Similar as LZ4_compress_HC_continue(), + * but will read a variable nb of bytes from `src` + * to fit into `targetDstSize` budget. + * Result is provided in 2 parts : + * @return : the number of bytes written into 'dst' + * or 0 if compression fails. + * `srcSizePtr` : value will be updated to indicate how much bytes were read from `src`. + */ +int LZ4_compress_HC_continue_destSize(LZ4_streamHC_t* LZ4_streamHCPtr, + const char* src, char* dst, + int* srcSizePtr, int targetDstSize); + +/*! 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() : + * 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 + * when the stream is in an indeterminate state (i.e., the reset performed by + * LZ4_resetStreamHC()). + * + * LZ4_streamHCs are guaranteed to be in a valid state when: + * - returned from LZ4_createStreamHC() + * - reset by LZ4_resetStreamHC() + * - memset(stream, 0, sizeof(LZ4_streamHC_t)) + * - the stream was in a valid state and was reset by LZ4_resetStreamHC_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 (LZ4_compress_HC_extStateHC()) and that + * returned success + */ +void LZ4_resetStreamHC_fast(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); + +/*! LZ4_compress_HC_extStateHC_fastReset() : + * A variant of LZ4_compress_HC_extStateHC(). + * + * 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_resetStreamHC_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 + * 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); + +/*! LZ4_attach_HC_dictionary() : + * This is an experimental API that allows for the 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_streamHC_t into a + * working LZ4_streamHC_t, this function introduces a no-copy setup mechanism, + * in which the working stream references the dictionary stream in-place. + * + * Several assumptions are made about the state of the dictionary stream. + * Currently, only streams which have been prepared by LZ4_loadDictHC() should + * be expected to work. + * + * Alternatively, the provided dictionary stream pointer may be NULL, in which + * case any existing dictionary stream is unset. + * + * A dictionary should only be attached to a stream without any history (i.e., + * a stream that has just been reset). + * + * The dictionary will remain attached to the working stream only for the + * current stream session. Calls to LZ4_resetStreamHC(_fast) will remove the + * dictionary context association from the working stream. The dictionary + * 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); + +#if defined (__cplusplus) +} +#endif + +#endif /* LZ4_HC_SLO_098092834 */ +#endif /* LZ4_HC_STATIC_LINKING_ONLY */ |