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Diffstat (limited to 'lib/lz4/lz4hc.h')
| -rw-r--r-- | lib/lz4/lz4hc.h | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/lib/lz4/lz4hc.h b/lib/lz4/lz4hc.h new file mode 100644 index 0000000..157d813 --- /dev/null +++ b/lib/lz4/lz4hc.h @@ -0,0 +1,307 @@ +/* + LZ4 HC - High Compression Mode of LZ4 + Header File + 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 + 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 source repository : https://github.com/lz4/lz4 + - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c +*/ +#ifndef LZ4_HC_H_19834876238432 +#define LZ4_HC_H_19834876238432 + +#if defined (__cplusplus) +extern "C" { +#endif + +/* --- Dependency --- */ +/* 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 10 +#define LZ4HC_CLEVEL_MAX 12 + + +/*-************************************ + * Block Compression + **************************************/ +/*! LZ4_compress_HC() : + * 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") + * `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. + */ +LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel); + + +/* Note : + * Decompression functions are provided within "lz4.h" (BSD license) + */ + + +/*! LZ4_compress_HC_extStateHC() : + * 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() should do properly). + */ +LZ4LIB_API int LZ4_sizeofStateHC(void); +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); + + +/*-************************************ + * Streaming Compression + * Bufferless synchronous API + **************************************/ + typedef union LZ4_streamHC_u LZ4_streamHC_t; /* incomplete type (defined later) */ + +/* + 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+ */ + +/*^********************************************** + * !!!!!! STATIC LINKING ONLY !!!!!! + ***********************************************/ + +/*-****************************************************************** + * PRIVATE DEFINITIONS : + * 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_DICTIONARY_LOGSIZE) +#define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1) + +#define LZ4HC_HASH_LOG 15 +#define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG) +#define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1) + + +#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) +#include <stdint.h> + +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 */ + 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; + int8_t favorDecSpeed; /* favor decompression speed if this flag set, + otherwise, favor compression ratio */ + int8_t dirty; /* stream has to be fully reset if this flag is set */ + const LZ4HC_CCtx_internal* dictCtx; +}; + +#else + +typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal; +struct LZ4HC_CCtx_internal +{ + unsigned int hashTable[LZ4HC_HASHTABLESIZE]; + 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 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 */ + short compressionLevel; + char favorDecSpeed; /* favor decompression speed if this flag set, + otherwise, favor compression ratio */ + char dirty; /* stream has to be fully reset if this flag is set */ + const LZ4HC_CCtx_internal* dictCtx; +}; + +#endif + + +/* Do not use these definitions directly ! + * Declare or allocate an LZ4_streamHC_t instead. + */ +#define LZ4_STREAMHCSIZE (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56 + ((sizeof(void*)==16) ? 56 : 0) /* AS400*/ ) /* 262200 or 262256*/ +#define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t)) +union LZ4_streamHC_u { + size_t table[LZ4_STREAMHCSIZE_SIZET]; + LZ4HC_CCtx_internal internal_donotuse; +}; /* previously typedef'd to LZ4_streamHC_t */ + +/* LZ4_streamHC_t : + * This structure allows static allocation of LZ4 HC streaming state. + * This can be used to allocate statically, on state, or as part of a larger structure. + * + * Such state **must** be initialized using LZ4_initStreamHC() before first use. + * + * Note that invoking LZ4_initStreamHC() is not required when + * the state was created using LZ4_createStreamHC() (which is recommended). + * Using the normal builder, a newly created state is automatically initialized. + * + * Static allocation shall only be used in combination with static linking. + */ + +/* LZ4_initStreamHC() : v1.9.0+ + * Required before first use of a statically allocated LZ4_streamHC_t. + * Before v1.9.0 : use LZ4_resetStreamHC() instead + */ +LZ4LIB_API LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size); + +#if defined (__cplusplus) +} +#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 + +#define LZ4_STATIC_LINKING_ONLY /* LZ4LIB_STATIC_API */ +#include "lz4.h" + +#if defined (__cplusplus) +extern "C" { +#endif + +/*! LZ4_setCompressionLevel() : v1.8.0+ (experimental) + * It's possible to change compression level + * between successive invocations of LZ4_compress_HC_continue*() + * for dynamic adaptation. + */ +LZ4LIB_STATIC_API void LZ4_setCompressionLevel( + LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); + +/*! 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 + * 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 + * + * 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. + */ +LZ4LIB_STATIC_API void LZ4_resetStreamHC_fast( + LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel); + +#if defined (__cplusplus) +} +#endif + +#endif /* LZ4_HC_SLO_098092834 */ +#endif /* LZ4_HC_STATIC_LINKING_ONLY */ |