1 /* 2 LZ4 - Fast LZ compression algorithm 3 Header File 4 Copyright (C) 2011-2013, 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 homepage : http://fastcompression.blogspot.com/p/lz4.html 32 - LZ4 source repository : http://code.google.com/p/lz4/ 33 */ 34 #pragma once 35 36 #if defined (__cplusplus) 37 extern "C" { 38 #endif 39 40 41 /************************************** 42 Version 43 **************************************/ 44 #define LZ4_VERSION_MAJOR 1 /* for major interface/format changes */ 45 #define LZ4_VERSION_MINOR 1 /* for minor interface/format changes */ 46 #define LZ4_VERSION_RELEASE 3 /* for tweaks, bug-fixes, or development */ 47 48 49 /************************************** 50 Compiler Options 51 **************************************/ 52 #if (defined(__GNUC__) && defined(__STRICT_ANSI__)) || (defined(_MSC_VER) && !defined(__cplusplus)) /* Visual Studio */ 53 # define inline __inline /* Visual C is not C99, but supports some kind of inline */ 54 #endif 55 56 57 /************************************** 58 Simple Functions 59 **************************************/ 60 61 int LZ4_compress (const char* source, char* dest, int inputSize); 62 int LZ4_decompress_safe (const char* source, char* dest, int inputSize, int maxOutputSize); 63 64 /* 65 LZ4_compress() : 66 Compresses 'inputSize' bytes from 'source' into 'dest'. 67 Destination buffer must be already allocated, 68 and must be sized to handle worst cases situations (input data not compressible) 69 Worst case size evaluation is provided by function LZ4_compressBound() 70 inputSize : Max supported value is LZ4_MAX_INPUT_VALUE 71 return : the number of bytes written in buffer dest 72 or 0 if the compression fails 73 74 LZ4_decompress_safe() : 75 maxOutputSize : is the size of the destination buffer (which must be already allocated) 76 return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize) 77 If the source stream is detected malformed, the function will stop decoding and return a negative result. 78 This function is protected against buffer overflow exploits (never writes outside of output buffer, and never reads outside of input buffer). Therefore, it is protected against malicious data packets 79 */ 80 81 82 /************************************** 83 Advanced Functions 84 **************************************/ 85 #define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */ 86 #define LZ4_COMPRESSBOUND(isize) ((unsigned int)(isize) > (unsigned int)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16) 87 88 /* 89 LZ4_compressBound() : 90 Provides the maximum size that LZ4 may output in a "worst case" scenario (input data not compressible) 91 primarily useful for memory allocation of output buffer. 92 inline function is recommended for the general case, 93 macro is also provided when result needs to be evaluated at compilation (such as stack memory allocation). 94 95 isize : is the input size. Max supported value is LZ4_MAX_INPUT_SIZE 96 return : maximum output size in a "worst case" scenario 97 or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE) 98 */ 99 int LZ4_compressBound(int isize); 100 101 102 /* 103 LZ4_compress_limitedOutput() : 104 Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'. 105 If it cannot achieve it, compression will stop, and result of the function will be zero. 106 This function never writes outside of provided output buffer. 107 108 inputSize : Max supported value is LZ4_MAX_INPUT_VALUE 109 maxOutputSize : is the size of the destination buffer (which must be already allocated) 110 return : the number of bytes written in buffer 'dest' 111 or 0 if the compression fails 112 */ 113 int LZ4_compress_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize); 114 115 116 /* 117 LZ4_decompress_fast() : 118 originalSize : is the original and therefore uncompressed size 119 return : the number of bytes read from the source buffer (in other words, the compressed size) 120 If the source stream is malformed, the function will stop decoding and return a negative result. 121 note : This function is a bit faster than LZ4_decompress_safe() 122 This function never writes outside of output buffers, but may read beyond input buffer in case of malicious data packet. 123 Use this function preferably into a trusted environment (data to decode comes from a trusted source). 124 Destination buffer must be already allocated. Its size must be a minimum of 'outputSize' bytes. 125 */ 126 int LZ4_decompress_fast (const char* source, char* dest, int originalSize); 127 128 129 /* 130 LZ4_decompress_safe_partial() : 131 This function decompress a compressed block of size 'inputSize' at position 'source' 132 into output buffer 'dest' of size 'maxOutputSize'. 133 The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached, 134 reducing decompression time. 135 return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize) 136 Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller. 137 Always control how many bytes were decoded. 138 If the source stream is detected malformed, the function will stop decoding and return a negative result. 139 This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets 140 */ 141 int LZ4_decompress_safe_partial (const char* source, char* dest, int inputSize, int targetOutputSize, int maxOutputSize); 142 143 144 /* 145 These functions are provided should you prefer to allocate memory for compression tables with your own allocation methods. 146 To know how much memory must be allocated for the compression tables, use : 147 int LZ4_sizeofState(); 148 149 Note that tables must be aligned on 4-bytes boundaries, otherwise compression will fail (return code 0). 150 151 The allocated memory can be provided to the compressions functions using 'void* state' parameter. 152 LZ4_compress_withState() and LZ4_compress_limitedOutput_withState() are equivalent to previously described functions. 153 They just use the externally allocated memory area instead of allocating their own (on stack, or on heap). 154 */ 155 int LZ4_sizeofState(void); 156 int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize); 157 int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); 158 159 160 /************************************** 161 Streaming Functions 162 **************************************/ 163 void* LZ4_create (const char* inputBuffer); 164 int LZ4_compress_continue (void* LZ4_Data, const char* source, char* dest, int inputSize); 165 int LZ4_compress_limitedOutput_continue (void* LZ4_Data, const char* source, char* dest, int inputSize, int maxOutputSize); 166 char* LZ4_slideInputBuffer (void* LZ4_Data); 167 int LZ4_free (void* LZ4_Data); 168 169 /* 170 These functions allow the compression of dependent blocks, where each block benefits from prior 64 KB within preceding blocks. 171 In order to achieve this, it is necessary to start creating the LZ4 Data Structure, thanks to the function : 172 173 void* LZ4_create (const char* inputBuffer); 174 The result of the function is the (void*) pointer on the LZ4 Data Structure. 175 This pointer will be needed in all other functions. 176 If the pointer returned is NULL, then the allocation has failed, and compression must be aborted. 177 The only parameter 'const char* inputBuffer' must, obviously, point at the beginning of input buffer. 178 The input buffer must be already allocated, and size at least 192KB. 179 'inputBuffer' will also be the 'const char* source' of the first block. 180 181 All blocks are expected to lay next to each other within the input buffer, starting from 'inputBuffer'. 182 To compress each block, use either LZ4_compress_continue() or LZ4_compress_limitedOutput_continue(). 183 Their behavior are identical to LZ4_compress() or LZ4_compress_limitedOutput(), 184 but require the LZ4 Data Structure as their first argument, and check that each block starts right after the previous one. 185 If next block does not begin immediately after the previous one, the compression will fail (return 0). 186 187 When it's no longer possible to lay the next block after the previous one (not enough space left into input buffer), a call to : 188 char* LZ4_slideInputBuffer(void* LZ4_Data); 189 must be performed. It will typically copy the latest 64KB of input at the beginning of input buffer. 190 Note that, for this function to work properly, minimum size of an input buffer must be 192KB. 191 ==> The memory position where the next input data block must start is provided as the result of the function. 192 193 Compression can then resume, using LZ4_compress_continue() or LZ4_compress_limitedOutput_continue(), as usual. 194 195 When compression is completed, a call to LZ4_free() will release the memory used by the LZ4 Data Structure. 196 */ 197 198 199 int LZ4_sizeofStreamState(void); 200 int LZ4_resetStreamState(void* state, const char* inputBuffer); 201 202 /* 203 These functions achieve the same result as : 204 void* LZ4_create (const char* inputBuffer); 205 206 They are provided here to allow the user program to allocate memory using its own routines. 207 208 To know how much space must be allocated, use LZ4_sizeofStreamState(); 209 Note also that space must be 4-bytes aligned. 210 211 Once space is allocated, you must initialize it using : LZ4_resetStreamState(void* state, const char* inputBuffer); 212 void* state is a pointer to the space allocated. 213 It must be aligned on 4-bytes boundaries, and be large enough. 214 The parameter 'const char* inputBuffer' must, obviously, point at the beginning of input buffer. 215 The input buffer must be already allocated, and size at least 192KB. 216 'inputBuffer' will also be the 'const char* source' of the first block. 217 218 The same space can be re-used multiple times, just by initializing it each time with LZ4_resetStreamState(). 219 return value of LZ4_resetStreamState() must be 0 is OK. 220 Any other value means there was an error (typically, pointer is not aligned on 4-bytes boundaries). 221 */ 222 223 224 int LZ4_decompress_safe_withPrefix64k (const char* source, char* dest, int inputSize, int maxOutputSize); 225 int LZ4_decompress_fast_withPrefix64k (const char* source, char* dest, int outputSize); 226 227 /* 228 *_withPrefix64k() : 229 These decoding functions work the same as their "normal name" versions, 230 but can use up to 64KB of data in front of 'char* dest'. 231 These functions are necessary to decode inter-dependant blocks. 232 */ 233 234 235 /************************************** 236 Obsolete Functions 237 **************************************/ 238 /* 239 These functions are deprecated and should no longer be used. 240 They are provided here for compatibility with existing user programs. 241 */ 242 int LZ4_uncompress (const char* source, char* dest, int outputSize); 243 int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); 244 245 246 #if defined (__cplusplus) 247 } 248 #endif 249