1 /* 2 LZ4 HC - High Compression Mode of LZ4 3 Header File 4 Copyright (C) 2011-2016, Yann Collet. 5 BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) 6 7 Redistribution and use in source and binary forms, with or without 8 modification, are permitted provided that the following conditions are 9 met: 10 11 * Redistributions of source code must retain the above copyright 12 notice, this list of conditions and the following disclaimer. 13 * Redistributions in binary form must reproduce the above 14 copyright notice, this list of conditions and the following disclaimer 15 in the documentation and/or other materials provided with the 16 distribution. 17 18 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30 You can contact the author at : 31 - LZ4 source repository : https://github.com/lz4/lz4 32 - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c 33 */ 34 #ifndef LZ4_HC_H_19834876238432 35 #define LZ4_HC_H_19834876238432 36 37 #if defined (__cplusplus) 38 extern "C" { 39 #endif 40 41 /* --- Dependency --- */ 42 /* note : lz4hc is not an independent module, it requires lz4.h/lz4.c for proper compilation */ 43 #include "lz4.h" /* stddef, LZ4LIB_API, LZ4_DEPRECATED */ 44 45 46 /* --- Useful constants --- */ 47 #define LZ4HC_CLEVEL_MIN 3 48 #define LZ4HC_CLEVEL_DEFAULT 9 49 #define LZ4HC_CLEVEL_OPT_MIN 11 50 #define LZ4HC_CLEVEL_MAX 12 51 52 53 /*-************************************ 54 * Block Compression 55 **************************************/ 56 /*! LZ4_compress_HC() : 57 * Compress data from `src` into `dst`, using the more powerful but slower "HC" algorithm. 58 * `dst` must be already allocated. 59 * Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h") 60 * Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h") 61 * `compressionLevel` : Recommended values are between 4 and 9, although any value between 1 and LZ4HC_MAX_CLEVEL will work. 62 * Values >LZ4HC_MAX_CLEVEL behave the same as LZ4HC_MAX_CLEVEL. 63 * @return : the number of bytes written into 'dst' 64 * or 0 if compression fails. 65 */ 66 LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel); 67 68 69 /* Note : 70 * Decompression functions are provided within "lz4.h" (BSD license) 71 */ 72 73 74 /*! LZ4_compress_HC_extStateHC() : 75 * Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`. 76 * `state` size is provided by LZ4_sizeofStateHC(). 77 * Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() will do properly). 78 */ 79 LZ4LIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel); 80 LZ4LIB_API int LZ4_sizeofStateHC(void); 81 82 83 /*-************************************ 84 * Streaming Compression 85 * Bufferless synchronous API 86 **************************************/ 87 typedef union LZ4_streamHC_u LZ4_streamHC_t; /* incomplete type (defined later) */ 88 89 /*! LZ4_createStreamHC() and LZ4_freeStreamHC() : 90 * These functions create and release memory for LZ4 HC streaming state. 91 * Newly created states are automatically initialized. 92 * Existing states can be re-used several times, using LZ4_resetStreamHC(). 93 * These methods are API and ABI stable, they can be used in combination with a DLL. 94 */ 95 LZ4LIB_API LZ4_streamHC_t* LZ4_createStreamHC(void); 96 LZ4LIB_API int LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr); 97 98 LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel); 99 LZ4LIB_API int LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize); 100 101 LZ4LIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr, const char* src, char* dst, int srcSize, int maxDstSize); 102 103 LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, int maxDictSize); 104 105 /* 106 These functions compress data in successive blocks of any size, using previous blocks as dictionary. 107 One key assumption is that previous blocks (up to 64 KB) remain read-accessible while compressing next blocks. 108 There is an exception for ring buffers, which can be smaller than 64 KB. 109 Ring buffers scenario is automatically detected and handled by LZ4_compress_HC_continue(). 110 111 Before starting compression, state must be properly initialized, using LZ4_resetStreamHC(). 112 A first "fictional block" can then be designated as initial dictionary, using LZ4_loadDictHC() (Optional). 113 114 Then, use LZ4_compress_HC_continue() to compress each successive block. 115 Previous memory blocks (including initial dictionary when present) must remain accessible and unmodified during compression. 116 'dst' buffer should be sized to handle worst case scenarios, using LZ4_compressBound(), to ensure operation success. 117 118 If, for any reason, previous data blocks can't be preserved unmodified in memory during next compression block, 119 you must save it to a safer memory space, using LZ4_saveDictHC(). 120 Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer'. 121 */ 122 123 124 /*-****************************************** 125 * !!!!! STATIC LINKING ONLY !!!!! 126 *******************************************/ 127 128 /*-************************************* 129 * PRIVATE DEFINITIONS : 130 * Do not use these definitions. 131 * They are exposed to allow static allocation of `LZ4_streamHC_t`. 132 * Using these definitions makes the code vulnerable to potential API break when upgrading LZ4 133 **************************************/ 134 #define LZ4HC_DICTIONARY_LOGSIZE 17 135 #define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE) 136 #define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1) 137 138 #define LZ4HC_HASH_LOG 15 139 #define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG) 140 #define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1) 141 142 143 #if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) 144 #include <stdint.h> 145 146 typedef struct 147 { 148 uint32_t hashTable[LZ4HC_HASHTABLESIZE]; 149 uint16_t chainTable[LZ4HC_MAXD]; 150 const uint8_t* end; /* next block here to continue on current prefix */ 151 const uint8_t* base; /* All index relative to this position */ 152 const uint8_t* dictBase; /* alternate base for extDict */ 153 uint8_t* inputBuffer; /* deprecated */ 154 uint32_t dictLimit; /* below that point, need extDict */ 155 uint32_t lowLimit; /* below that point, no more dict */ 156 uint32_t nextToUpdate; /* index from which to continue dictionary update */ 157 uint32_t searchNum; /* only for optimal parser */ 158 uint32_t compressionLevel; 159 } LZ4HC_CCtx_internal; 160 161 #else 162 163 typedef struct 164 { 165 unsigned int hashTable[LZ4HC_HASHTABLESIZE]; 166 unsigned short chainTable[LZ4HC_MAXD]; 167 const unsigned char* end; /* next block here to continue on current prefix */ 168 const unsigned char* base; /* All index relative to this position */ 169 const unsigned char* dictBase; /* alternate base for extDict */ 170 unsigned char* inputBuffer; /* deprecated */ 171 unsigned int dictLimit; /* below that point, need extDict */ 172 unsigned int lowLimit; /* below that point, no more dict */ 173 unsigned int nextToUpdate; /* index from which to continue dictionary update */ 174 unsigned int searchNum; /* only for optimal parser */ 175 unsigned int compressionLevel; 176 } LZ4HC_CCtx_internal; 177 178 #endif 179 180 #define LZ4_STREAMHCSIZE (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56) /* 393268 */ 181 #define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t)) 182 union LZ4_streamHC_u { 183 size_t table[LZ4_STREAMHCSIZE_SIZET]; 184 LZ4HC_CCtx_internal internal_donotuse; 185 }; /* previously typedef'd to LZ4_streamHC_t */ 186 /* 187 LZ4_streamHC_t : 188 This structure allows static allocation of LZ4 HC streaming state. 189 State must be initialized using LZ4_resetStreamHC() before first use. 190 191 Static allocation shall only be used in combination with static linking. 192 When invoking LZ4 from a DLL, use create/free functions instead, which are API and ABI stable. 193 */ 194 195 196 /*-************************************ 197 * Deprecated Functions 198 **************************************/ 199 /* see lz4.h LZ4_DISABLE_DEPRECATE_WARNINGS to turn off deprecation warnings */ 200 201 /* deprecated compression functions */ 202 /* these functions will trigger warning messages in future releases */ 203 LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC (const char* source, char* dest, int inputSize); 204 LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize); 205 LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel); 206 LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); 207 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize); 208 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); 209 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel); 210 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); 211 LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize); 212 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); 213 214 /* Deprecated Streaming functions using older model; should no longer be used */ 215 LZ4_DEPRECATED("use LZ4_createStreamHC() instead") void* LZ4_createHC (char* inputBuffer); 216 LZ4_DEPRECATED("use LZ4_saveDictHC() instead") char* LZ4_slideInputBufferHC (void* LZ4HC_Data); 217 LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") int LZ4_freeHC (void* LZ4HC_Data); 218 LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel); 219 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); 220 LZ4_DEPRECATED("use LZ4_createStreamHC() instead") int LZ4_sizeofStreamStateHC(void); 221 LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") int LZ4_resetStreamStateHC(void* state, char* inputBuffer); 222 223 224 #if defined (__cplusplus) 225 } 226 #endif 227 228 #endif /* LZ4_HC_H_19834876238432 */ 229
