2ece0d8380
- promoted LZ4_resetStream_fast() to stable - moved LZ4_resetStream() into deprecate, but without triggering a compiler warning - update all sources to no longer rely on LZ4_resetStream() note : LZ4_initStream() proposal is slightly different : it's able to initialize any buffer, provided that it's large enough. To this end, it accepts a void*, and returns an LZ4_stream_t*.
432 lines
21 KiB
C
432 lines
21 KiB
C
/*
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LZ4 HC - High Compression Mode of LZ4
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Header File
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Copyright (C) 2011-2017, Yann Collet.
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the following disclaimer
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in the documentation and/or other materials provided with the
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distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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You can contact the author at :
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- LZ4 source repository : https://github.com/lz4/lz4
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- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
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*/
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#ifndef LZ4_HC_H_19834876238432
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#define LZ4_HC_H_19834876238432
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#if defined (__cplusplus)
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extern "C" {
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#endif
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/* --- Dependency --- */
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/* note : lz4hc requires lz4.h/lz4.c for compilation */
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#include "lz4.h" /* stddef, LZ4LIB_API, LZ4_DEPRECATED */
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/* --- Useful constants --- */
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#define LZ4HC_CLEVEL_MIN 3
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#define LZ4HC_CLEVEL_DEFAULT 9
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#define LZ4HC_CLEVEL_OPT_MIN 10
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#define LZ4HC_CLEVEL_MAX 12
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/*-************************************
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* Block Compression
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**************************************/
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/*! LZ4_compress_HC() :
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* Compress data from `src` into `dst`, using the powerful but slower "HC" algorithm.
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* `dst` must be already allocated.
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* Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h")
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* Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h")
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* `compressionLevel` : any value between 1 and LZ4HC_CLEVEL_MAX will work.
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* Values > LZ4HC_CLEVEL_MAX behave the same as LZ4HC_CLEVEL_MAX.
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* @return : the number of bytes written into 'dst'
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* or 0 if compression fails.
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*/
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LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel);
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/* Note :
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* Decompression functions are provided within "lz4.h" (BSD license)
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*/
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/*! LZ4_compress_HC_extStateHC() :
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* Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`.
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* `state` size is provided by LZ4_sizeofStateHC().
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* Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() should do properly).
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*/
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LZ4LIB_API int LZ4_sizeofStateHC(void);
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LZ4LIB_API int LZ4_compress_HC_extStateHC(void* stateHC, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
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/*! LZ4_compress_HC_destSize() : v1.9.0+
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* Will compress as much data as possible from `src`
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* to fit into `targetDstSize` budget.
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* Result is provided in 2 parts :
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* @return : the number of bytes written into 'dst' (necessarily <= targetDstSize)
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* or 0 if compression fails.
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* `srcSizePtr` : on success, *srcSizePtr is updated to indicate how much bytes were read from `src`
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*/
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LZ4LIB_API int LZ4_compress_HC_destSize(void* stateHC,
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const char* src, char* dst,
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int* srcSizePtr, int targetDstSize,
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int compressionLevel);
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/*-************************************
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* Streaming Compression
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* Bufferless synchronous API
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**************************************/
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typedef union LZ4_streamHC_u LZ4_streamHC_t; /* incomplete type (defined later) */
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/*! LZ4_createStreamHC() and LZ4_freeStreamHC() :
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* These functions create and release memory for LZ4 HC streaming state.
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* Newly created states are automatically initialized.
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* A same state can be used multiple times consecutively,
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* starting with LZ4_resetStreamHC_fast() to start a new stream of blocks.
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*/
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LZ4LIB_API LZ4_streamHC_t* LZ4_createStreamHC(void);
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LZ4LIB_API int LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr);
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/*
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These functions compress data in successive blocks of any size,
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using previous blocks as dictionary, to improve compression ratio.
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One key assumption is that previous blocks (up to 64 KB) remain read-accessible while compressing next blocks.
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There is an exception for ring buffers, which can be smaller than 64 KB.
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Ring-buffer scenario is automatically detected and handled within LZ4_compress_HC_continue().
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Before starting compression, state must be allocated and properly initialized.
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LZ4_createStreamHC() does both, though compression level is set to LZ4HC_CLEVEL_DEFAULT.
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Selecting the compression level can be done with LZ4_resetStreamHC_fast() (starts a new stream)
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or LZ4_setCompressionLevel() (anytime, between blocks in the same stream) (experimental).
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LZ4_resetStreamHC_fast() only works on states which have been properly initialized at least once,
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which is automatically the case when state is created using LZ4_createStreamHC().
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After reset, a first "fictional block" can be designated as initial dictionary,
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using LZ4_loadDictHC() (Optional).
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Invoke LZ4_compress_HC_continue() to compress each successive block.
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The number of blocks is unlimited.
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Previous input blocks, including initial dictionary when present,
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must remain accessible and unmodified during compression.
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It's allowed to update compression level anytime between blocks,
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using LZ4_setCompressionLevel() (experimental).
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'dst' buffer should be sized to handle worst case scenarios
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(see LZ4_compressBound(), it ensures compression success).
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In case of failure, the API does not guarantee recovery,
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so the state _must_ be reset.
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To ensure compression success
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whenever `dst` buffer size cannot be made >= LZ4_compressBound(),
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consider using LZ4_compress_HC_continue_destSize().
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Whenever previous input blocks can't be preserved unmodified in-place during compression of next blocks,
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it's possible to copy the last blocks into a more stable memory space, using LZ4_saveDictHC().
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Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer' (<= 64 KB)
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After completing a streaming compression,
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it's possible to start a new stream of blocks, using the same LZ4_streamHC_t state,
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just by resetting it, using LZ4_resetStreamHC_fast().
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*/
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LZ4LIB_API void LZ4_resetStreamHC_fast(LZ4_streamHC_t* streamHCPtr, int compressionLevel); /* v1.9.0+ */
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LZ4LIB_API int LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize);
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LZ4LIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr,
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const char* src, char* dst,
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int srcSize, int maxDstSize);
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/*! LZ4_compress_HC_continue_destSize() : v1.9.0+
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* Similar to LZ4_compress_HC_continue(),
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* but will read as much data as possible from `src`
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* to fit into `targetDstSize` budget.
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* Result is provided into 2 parts :
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* @return : the number of bytes written into 'dst' (necessarily <= targetDstSize)
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* or 0 if compression fails.
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* `srcSizePtr` : on success, *srcSizePtr will be updated to indicate how much bytes were read from `src`.
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* Note that this function may not consume the entire input.
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*/
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LZ4LIB_API int LZ4_compress_HC_continue_destSize(LZ4_streamHC_t* LZ4_streamHCPtr,
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const char* src, char* dst,
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int* srcSizePtr, int targetDstSize);
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LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, int maxDictSize);
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/*^**********************************************
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* !!!!!! STATIC LINKING ONLY !!!!!!
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***********************************************/
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/*-******************************************************************
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* PRIVATE DEFINITIONS :
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* Do not use these definitions directly.
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* They are merely exposed to allow static allocation of `LZ4_streamHC_t`.
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* Declare an `LZ4_streamHC_t` directly, rather than any type below.
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* Even then, only do so in the context of static linking, as definitions may change between versions.
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********************************************************************/
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#define LZ4HC_DICTIONARY_LOGSIZE 16
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#define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE)
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#define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1)
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#define LZ4HC_HASH_LOG 15
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#define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG)
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#define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1)
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#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
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#include <stdint.h>
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typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal;
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struct LZ4HC_CCtx_internal
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{
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uint32_t hashTable[LZ4HC_HASHTABLESIZE];
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uint16_t chainTable[LZ4HC_MAXD];
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const uint8_t* end; /* next block here to continue on current prefix */
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const uint8_t* base; /* All index relative to this position */
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const uint8_t* dictBase; /* alternate base for extDict */
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uint32_t dictLimit; /* below that point, need extDict */
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uint32_t lowLimit; /* below that point, no more dict */
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uint32_t nextToUpdate; /* index from which to continue dictionary update */
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short compressionLevel;
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int8_t favorDecSpeed; /* favor decompression speed if this flag set,
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otherwise, favor compression ratio */
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int8_t dirty; /* stream has to be fully reset if this flag is set */
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const LZ4HC_CCtx_internal* dictCtx;
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};
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#else
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typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal;
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struct LZ4HC_CCtx_internal
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{
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unsigned int hashTable[LZ4HC_HASHTABLESIZE];
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unsigned short chainTable[LZ4HC_MAXD];
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const unsigned char* end; /* next block here to continue on current prefix */
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const unsigned char* base; /* All index relative to this position */
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const unsigned char* dictBase; /* alternate base for extDict */
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unsigned int dictLimit; /* below that point, need extDict */
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unsigned int lowLimit; /* below that point, no more dict */
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unsigned int nextToUpdate; /* index from which to continue dictionary update */
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short compressionLevel;
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char favorDecSpeed; /* favor decompression speed if this flag set,
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otherwise, favor compression ratio */
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char dirty; /* stream has to be fully reset if this flag is set */
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const LZ4HC_CCtx_internal* dictCtx;
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};
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#endif
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/* Do not use these definitions directly !
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* Declare or allocate an LZ4_streamHC_t instead.
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*/
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#define LZ4_STREAMHCSIZE (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56 + ((sizeof(void*)==16) ? 56 : 0) /* AS400*/ ) /* 262200 or 262256*/
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#define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t))
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union LZ4_streamHC_u {
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size_t table[LZ4_STREAMHCSIZE_SIZET];
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LZ4HC_CCtx_internal internal_donotuse;
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}; /* previously typedef'd to LZ4_streamHC_t */
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/* LZ4_streamHC_t :
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* This structure allows static allocation of LZ4 HC streaming state.
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* This can be used to allocate statically, on state, or as part of a larger structure.
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*
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* Such state **must** be initialized using LZ4_initStreamHC() before first use.
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*
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* Note that invoking LZ4_initStreamHC() is not required when
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* the state was created using LZ4_createStreamHC() (which is recommended).
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* Using the normal builder, a newly created state is automatically initialized.
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*
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* Static allocation shall only be used in combination with static linking.
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*/
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LZ4LIB_API void LZ4_initStreamHC (void* streamHCPtr, int compressionLevel); /* v1.9.0+ */
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/*-************************************
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* Deprecated Functions
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**************************************/
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/* see lz4.h LZ4_DISABLE_DEPRECATE_WARNINGS to turn off deprecation warnings */
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/* deprecated compression functions */
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LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC (const char* source, char* dest, int inputSize);
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LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
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LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
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LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
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LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize);
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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);
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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);
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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);
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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);
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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);
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/* Obsolete streaming functions; degraded functionality; do not use!
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*
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* In order to perform streaming compression, these functions depended on data
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* that is no longer tracked in the state. They have been preserved as well as
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* possible: using them will still produce a correct output. However, use of
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* LZ4_slideInputBufferHC() will truncate the history of the stream, rather
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* than preserve a window-sized chunk of history.
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*/
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LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API void* LZ4_createHC (const char* inputBuffer);
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LZ4_DEPRECATED("use LZ4_saveDictHC() instead") LZ4LIB_API char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
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LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") LZ4LIB_API int LZ4_freeHC (void* LZ4HC_Data);
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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);
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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);
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LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API int LZ4_sizeofStreamStateHC(void);
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LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") LZ4LIB_API int LZ4_resetStreamStateHC(void* state, char* inputBuffer);
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/* LZ4_resetStreamHC() is now replaced by LZ4_initStreamHC().
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* The intention is to emphasize the difference with LZ4_resetStreamHC_fast(),
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* which is now the recommended function to start a new stream of blocks,
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* but cannot be used to initialize a memory segment containing arbitrary garbage data.
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*
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* It is recommended to switch to LZ4_initStreamHC().
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* LZ4_resetStreamHC() will generate deprecation warnings in a future version.
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*/
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LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel);
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#if defined (__cplusplus)
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}
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#endif
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#endif /* LZ4_HC_H_19834876238432 */
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/*-**************************************************
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* !!!!! STATIC LINKING ONLY !!!!!
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* Following definitions are considered experimental.
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* They should not be linked from DLL,
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* as there is no guarantee of API stability yet.
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* Prototypes will be promoted to "stable" status
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* after successfull usage in real-life scenarios.
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***************************************************/
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#ifdef LZ4_HC_STATIC_LINKING_ONLY /* protection macro */
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#ifndef LZ4_HC_SLO_098092834
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#define LZ4_HC_SLO_098092834
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#if defined (__cplusplus)
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extern "C" {
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#endif
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/*! LZ4_setCompressionLevel() : v1.8.0+ (experimental)
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* It's possible to change compression level
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* between successive invocations of LZ4_compress_HC_continue*()
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* for dynamic adaptation.
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*/
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LZ4LIB_STATIC_API void LZ4_setCompressionLevel(
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LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
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/*! LZ4_favorDecompressionSpeed() : v1.8.2+ (experimental)
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* Opt. Parser will favor decompression speed over compression ratio.
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* Only applicable to levels >= LZ4HC_CLEVEL_OPT_MIN.
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*/
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LZ4LIB_STATIC_API void LZ4_favorDecompressionSpeed(
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LZ4_streamHC_t* LZ4_streamHCPtr, int favor);
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/*! LZ4_resetStreamHC_fast() :
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* When an LZ4_streamHC_t is known to be in a internally coherent state,
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* it can often be prepared for a new compression with almost no work, only
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* sometimes falling back to the full, expensive reset that is always required
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* when the stream is in an indeterminate state (i.e., the reset performed by
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* LZ4_resetStreamHC()).
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*
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* LZ4_streamHCs are guaranteed to be in a valid state when:
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* - returned from LZ4_createStreamHC()
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* - reset by LZ4_resetStreamHC()
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* - memset(stream, 0, sizeof(LZ4_streamHC_t))
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* - the stream was in a valid state and was reset by LZ4_resetStreamHC_fast()
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* - the stream was in a valid state and was then used in any compression call
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* that returned success
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* - the stream was in an indeterminate state and was used in a compression
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* call that fully reset the state (LZ4_compress_HC_extStateHC()) and that
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* returned success
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*
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* Note:
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* A stream that was last used in a compression call that returned an error
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* may be passed to this function. However, it will be fully reset, which will
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* clear any existing history and settings from the context.
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*/
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LZ4LIB_STATIC_API void LZ4_resetStreamHC_fast(
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LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
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/*! LZ4_compress_HC_extStateHC_fastReset() :
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* A variant of LZ4_compress_HC_extStateHC().
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*
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* Using this variant avoids an expensive initialization step. It is only safe
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* 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().
|
|
*/
|
|
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
|
|
* 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_STATIC_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 */
|