1 /* 2 LZ4 - Fast LZ compression algorithm 3 Header File 4 Copyright (C) 2011-2015, Yann Collet. 5 6 BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) 7 8 Redistribution and use in source and binary forms, with or without 9 modification, are permitted provided that the following conditions are 10 met: 11 12 * Redistributions of source code must retain the above copyright 13 notice, this list of conditions and the following disclaimer. 14 * Redistributions in binary form must reproduce the above 15 copyright notice, this list of conditions and the following disclaimer 16 in the documentation and/or other materials provided with the 17 distribution. 18 19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 You can contact the author at : 32 - LZ4 source repository : https://github.com/Cyan4973/lz4 33 - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c 34 */ 35 #pragma once 36 37 #if defined (__cplusplus) 38 extern "C" { 39 #endif 40 41 /* 42 * lz4.h provides block compression functions, and gives full buffer control to programmer. 43 * If you need to generate inter-operable compressed data (respecting LZ4 frame specification), 44 * and can let the library handle its own memory, please use lz4frame.h instead. 45 */ 46 47 /************************************** 48 * Version 49 **************************************/ 50 #define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */ 51 #define LZ4_VERSION_MINOR 7 /* for new (non-breaking) interface capabilities */ 52 #define LZ4_VERSION_RELEASE 1 /* for tweaks, bug-fixes, or development */ 53 #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE) 54 int LZ4_versionNumber (void); 55 56 /************************************** 57 * Tuning parameter 58 **************************************/ 59 /* 60 * LZ4_MEMORY_USAGE : 61 * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) 62 * Increasing memory usage improves compression ratio 63 * Reduced memory usage can improve speed, due to cache effect 64 * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache 65 */ 66 #define LZ4_MEMORY_USAGE 14 67 68 69 /************************************** 70 * Simple Functions 71 **************************************/ 72 73 int LZ4_compress_default(const char* source, char* dest, int sourceSize, int maxDestSize); 74 int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize); 75 76 /* 77 LZ4_compress_default() : 78 Compresses 'sourceSize' bytes from buffer 'source' 79 into already allocated 'dest' buffer of size 'maxDestSize'. 80 Compression is guaranteed to succeed if 'maxDestSize' >= LZ4_compressBound(sourceSize). 81 It also runs faster, so it's a recommended setting. 82 If the function cannot compress 'source' into a more limited 'dest' budget, 83 compression stops *immediately*, and the function result is zero. 84 As a consequence, 'dest' content is not valid. 85 This function never writes outside 'dest' buffer, nor read outside 'source' buffer. 86 sourceSize : Max supported value is LZ4_MAX_INPUT_VALUE 87 maxDestSize : full or partial size of buffer 'dest' (which must be already allocated) 88 return : the number of bytes written into buffer 'dest' (necessarily <= maxOutputSize) 89 or 0 if compression fails 90 91 LZ4_decompress_safe() : 92 compressedSize : is the precise full size of the compressed block. 93 maxDecompressedSize : is the size of destination buffer, which must be already allocated. 94 return : the number of bytes decompressed into destination buffer (necessarily <= maxDecompressedSize) 95 If destination buffer is not large enough, decoding will stop and output an error code (<0). 96 If the source stream is detected malformed, the function will stop decoding and return a negative result. 97 This function is protected against buffer overflow exploits, including malicious data packets. 98 It never writes outside output buffer, nor reads outside input buffer. 99 */ 100 101 102 /************************************** 103 * Advanced Functions 104 **************************************/ 105 #define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */ 106 #define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16) 107 108 /* 109 LZ4_compressBound() : 110 Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible) 111 This function is primarily useful for memory allocation purposes (destination buffer size). 112 Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example). 113 Note that LZ4_compress_default() compress faster when dest buffer size is >= LZ4_compressBound(srcSize) 114 inputSize : max supported value is LZ4_MAX_INPUT_SIZE 115 return : maximum output size in a "worst case" scenario 116 or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE) 117 */ 118 int LZ4_compressBound(int inputSize); 119 120 /* 121 LZ4_compress_fast() : 122 Same as LZ4_compress_default(), but allows to select an "acceleration" factor. 123 The larger the acceleration value, the faster the algorithm, but also the lesser the compression. 124 It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed. 125 An acceleration value of "1" is the same as regular LZ4_compress_default() 126 Values <= 0 will be replaced by ACCELERATION_DEFAULT (see lz4.c), which is 1. 127 */ 128 int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, int acceleration); 129 130 131 /* 132 LZ4_compress_fast_extState() : 133 Same compression function, just using an externally allocated memory space to store compression state. 134 Use LZ4_sizeofState() to know how much memory must be allocated, 135 and allocate it on 8-bytes boundaries (using malloc() typically). 136 Then, provide it as 'void* state' to compression function. 137 */ 138 int LZ4_sizeofState(void); 139 int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, int acceleration); 140 141 142 /* 143 LZ4_compress_destSize() : 144 Reverse the logic, by compressing as much data as possible from 'source' buffer 145 into already allocated buffer 'dest' of size 'targetDestSize'. 146 This function either compresses the entire 'source' content into 'dest' if it's large enough, 147 or fill 'dest' buffer completely with as much data as possible from 'source'. 148 *sourceSizePtr : will be modified to indicate how many bytes where read from 'source' to fill 'dest'. 149 New value is necessarily <= old value. 150 return : Nb bytes written into 'dest' (necessarily <= targetDestSize) 151 or 0 if compression fails 152 */ 153 int LZ4_compress_destSize (const char* source, char* dest, int* sourceSizePtr, int targetDestSize); 154 155 156 /* 157 LZ4_decompress_fast() : 158 originalSize : is the original and therefore uncompressed size 159 return : the number of bytes read from the source buffer (in other words, the compressed size) 160 If the source stream is detected malformed, the function will stop decoding and return a negative result. 161 Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes. 162 note : This function fully respect memory boundaries for properly formed compressed data. 163 It is a bit faster than LZ4_decompress_safe(). 164 However, it does not provide any protection against intentionally modified data stream (malicious input). 165 Use this function in trusted environment only (data to decode comes from a trusted source). 166 */ 167 int LZ4_decompress_fast (const char* source, char* dest, int originalSize); 168 169 /* 170 LZ4_decompress_safe_partial() : 171 This function decompress a compressed block of size 'compressedSize' at position 'source' 172 into destination buffer 'dest' of size 'maxDecompressedSize'. 173 The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached, 174 reducing decompression time. 175 return : the number of bytes decoded in the destination buffer (necessarily <= maxDecompressedSize) 176 Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller. 177 Always control how many bytes were decoded. 178 If the source stream is detected malformed, the function will stop decoding and return a negative result. 179 This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets 180 */ 181 int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize); 182 183 184 /*********************************************** 185 * Streaming Compression Functions 186 ***********************************************/ 187 #define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4) 188 #define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(long long)) 189 /* 190 * LZ4_stream_t 191 * information structure to track an LZ4 stream. 192 * important : init this structure content before first use ! 193 * note : only allocated directly the structure if you are statically linking LZ4 194 * If you are using liblz4 as a DLL, please use below construction methods instead. 195 */ 196 typedef struct { long long table[LZ4_STREAMSIZE_U64]; } LZ4_stream_t; 197 198 /* 199 * LZ4_resetStream 200 * Use this function to init an allocated LZ4_stream_t structure 201 */ 202 void LZ4_resetStream (LZ4_stream_t* streamPtr); 203 204 /* 205 * LZ4_createStream will allocate and initialize an LZ4_stream_t structure 206 * LZ4_freeStream releases its memory. 207 * In the context of a DLL (liblz4), please use these methods rather than the static struct. 208 * They are more future proof, in case of a change of LZ4_stream_t size. 209 */ 210 LZ4_stream_t* LZ4_createStream(void); 211 int LZ4_freeStream (LZ4_stream_t* streamPtr); 212 213 /* 214 * LZ4_loadDict 215 * Use this function to load a static dictionary into LZ4_stream. 216 * Any previous data will be forgotten, only 'dictionary' will remain in memory. 217 * Loading a size of 0 is allowed. 218 * Return : dictionary size, in bytes (necessarily <= 64 KB) 219 */ 220 int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize); 221 222 /* 223 * LZ4_compress_fast_continue 224 * Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio. 225 * Important : Previous data blocks are assumed to still be present and unmodified ! 226 * 'dst' buffer must be already allocated. 227 * If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster. 228 * If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function returns a zero. 229 */ 230 int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration); 231 232 /* 233 * LZ4_saveDict 234 * If previously compressed data block is not guaranteed to remain available at its memory location 235 * save it into a safer place (char* safeBuffer) 236 * Note : you don't need to call LZ4_loadDict() afterwards, 237 * dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue() 238 * Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error 239 */ 240 int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize); 241 242 243 /************************************************ 244 * Streaming Decompression Functions 245 ************************************************/ 246 247 #define LZ4_STREAMDECODESIZE_U64 4 248 #define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long)) 249 typedef struct { unsigned long long table[LZ4_STREAMDECODESIZE_U64]; } LZ4_streamDecode_t; 250 /* 251 * LZ4_streamDecode_t 252 * information structure to track an LZ4 stream. 253 * init this structure content using LZ4_setStreamDecode or memset() before first use ! 254 * 255 * In the context of a DLL (liblz4) please prefer usage of construction methods below. 256 * They are more future proof, in case of a change of LZ4_streamDecode_t size in the future. 257 * LZ4_createStreamDecode will allocate and initialize an LZ4_streamDecode_t structure 258 * LZ4_freeStreamDecode releases its memory. 259 */ 260 LZ4_streamDecode_t* LZ4_createStreamDecode(void); 261 int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream); 262 263 /* 264 * LZ4_setStreamDecode 265 * Use this function to instruct where to find the dictionary. 266 * Setting a size of 0 is allowed (same effect as reset). 267 * Return : 1 if OK, 0 if error 268 */ 269 int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize); 270 271 /* 272 *_continue() : 273 These decoding functions allow decompression of multiple blocks in "streaming" mode. 274 Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB) 275 In the case of a ring buffers, decoding buffer must be either : 276 - Exactly same size as encoding buffer, with same update rule (block boundaries at same positions) 277 In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB). 278 - Larger than encoding buffer, by a minimum of maxBlockSize more bytes. 279 maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block. 280 In which case, encoding and decoding buffers do not need to be synchronized, 281 and encoding ring buffer can have any size, including small ones ( < 64 KB). 282 - _At least_ 64 KB + 8 bytes + maxBlockSize. 283 In which case, encoding and decoding buffers do not need to be synchronized, 284 and encoding ring buffer can have any size, including larger than decoding buffer. 285 Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer, 286 and indicate where it is saved using LZ4_setStreamDecode() 287 */ 288 int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize); 289 int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize); 290 291 292 /* 293 Advanced decoding functions : 294 *_usingDict() : 295 These decoding functions work the same as 296 a combination of LZ4_setStreamDecode() followed by LZ4_decompress_x_continue() 297 They are stand-alone. They don't need nor update an LZ4_streamDecode_t structure. 298 */ 299 int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize); 300 int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize); 301 302 303 304 /************************************** 305 * Obsolete Functions 306 **************************************/ 307 /* Deprecate Warnings */ 308 /* Should these warnings messages be a problem, 309 it is generally possible to disable them, 310 with -Wno-deprecated-declarations for gcc 311 or _CRT_SECURE_NO_WARNINGS in Visual for example. 312 You can also define LZ4_DEPRECATE_WARNING_DEFBLOCK. */ 313 #ifndef LZ4_DEPRECATE_WARNING_DEFBLOCK 314 # define LZ4_DEPRECATE_WARNING_DEFBLOCK 315 # define LZ4_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__) 316 # if (LZ4_GCC_VERSION >= 405) || defined(__clang__) 317 # define LZ4_DEPRECATED(message) __attribute__((deprecated(message))) 318 # elif (LZ4_GCC_VERSION >= 301) 319 # define LZ4_DEPRECATED(message) __attribute__((deprecated)) 320 # elif defined(_MSC_VER) 321 # define LZ4_DEPRECATED(message) __declspec(deprecated(message)) 322 # else 323 # pragma message("WARNING: You need to implement LZ4_DEPRECATED for this compiler") 324 # define LZ4_DEPRECATED(message) 325 # endif 326 #endif /* LZ4_DEPRECATE_WARNING_DEFBLOCK */ 327 328 /* Obsolete compression functions */ 329 /* These functions are planned to start generate warnings by r131 approximately */ 330 int LZ4_compress (const char* source, char* dest, int sourceSize); 331 int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize); 332 int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize); 333 int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); 334 int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize); 335 int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize); 336 337 /* Obsolete decompression functions */ 338 /* These function names are completely deprecated and must no longer be used. 339 They are only provided here for compatibility with older programs. 340 - LZ4_uncompress is the same as LZ4_decompress_fast 341 - LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe 342 These function prototypes are now disabled; uncomment them only if you really need them. 343 It is highly recommended to stop using these prototypes and migrate to maintained ones */ 344 /* int LZ4_uncompress (const char* source, char* dest, int outputSize); */ 345 /* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */ 346 347 /* Obsolete streaming functions; use new streaming interface whenever possible */ 348 LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer); 349 LZ4_DEPRECATED("use LZ4_createStream() instead") int LZ4_sizeofStreamState(void); 350 LZ4_DEPRECATED("use LZ4_resetStream() instead") int LZ4_resetStreamState(void* state, char* inputBuffer); 351 LZ4_DEPRECATED("use LZ4_saveDict() instead") char* LZ4_slideInputBuffer (void* state); 352 353 /* Obsolete streaming decoding functions */ 354 LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize); 355 LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize); 356 357 358 #if defined (__cplusplus) 359 } 360 #endif 361