1 /* 2 LZ4 auto-framing library 3 Header File 4 Copyright (C) 2011-2015, 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 : http://code.google.com/p/lz4/ 32 - LZ4 source mirror : https://github.com/Cyan4973/lz4 33 - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c 34 */ 35 36 /* LZ4F is a stand-alone API to create LZ4-compressed frames 37 * fully conformant to specification v1.4.1. 38 * All related operations, including memory management, are handled by the library. 39 * You don't need lz4.h when using lz4frame.h. 40 * */ 41 42 #pragma once 43 44 #if defined (__cplusplus) 45 extern "C" { 46 #endif 47 48 /************************************** 49 Includes 50 **************************************/ 51 #include <stddef.h> /* size_t */ 52 53 54 /************************************** 55 * Error management 56 * ************************************/ 57 typedef size_t LZ4F_errorCode_t; 58 59 unsigned LZ4F_isError(LZ4F_errorCode_t code); 60 const char* LZ4F_getErrorName(LZ4F_errorCode_t code); /* return error code string; useful for debugging */ 61 62 63 /************************************** 64 * Frame compression types 65 * ************************************/ 66 typedef enum { LZ4F_default=0, max64KB=4, max256KB=5, max1MB=6, max4MB=7 } blockSizeID_t; 67 typedef enum { blockLinked=0, blockIndependent} blockMode_t; 68 typedef enum { noContentChecksum=0, contentChecksumEnabled } contentChecksum_t; 69 70 typedef struct { 71 blockSizeID_t blockSizeID; /* max64KB, max256KB, max1MB, max4MB ; 0 == default */ 72 blockMode_t blockMode; /* blockLinked, blockIndependent ; 0 == default */ 73 contentChecksum_t contentChecksumFlag; /* noContentChecksum, contentChecksumEnabled ; 0 == default */ 74 unsigned reserved[5]; 75 } LZ4F_frameInfo_t; 76 77 typedef struct { 78 LZ4F_frameInfo_t frameInfo; 79 unsigned compressionLevel; /* 0 == default (fast mode); values above 16 count as 16 */ 80 unsigned autoFlush; /* 1 == always flush : reduce need for tmp buffer */ 81 unsigned reserved[4]; 82 } LZ4F_preferences_t; 83 84 85 /*********************************** 86 * Simple compression function 87 * *********************************/ 88 size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr); 89 90 size_t LZ4F_compressFrame(void* dstBuffer, size_t dstMaxSize, const void* srcBuffer, size_t srcSize, const LZ4F_preferences_t* preferencesPtr); 91 /* LZ4F_compressFrame() 92 * Compress an entire srcBuffer into a valid LZ4 frame, as defined by specification v1.4.1. 93 * The most important rule is that dstBuffer MUST be large enough (dstMaxSize) to ensure compression completion even in worst case. 94 * You can get the minimum value of dstMaxSize by using LZ4F_compressFrameBound() 95 * If this condition is not respected, LZ4F_compressFrame() will fail (result is an errorCode) 96 * The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default. 97 * The result of the function is the number of bytes written into dstBuffer. 98 * The function outputs an error code if it fails (can be tested using LZ4F_isError()) 99 */ 100 101 102 103 /********************************** 104 * Advanced compression functions 105 * ********************************/ 106 typedef void* LZ4F_compressionContext_t; 107 108 typedef struct { 109 unsigned stableSrc; /* 1 == src content will remain available on future calls to LZ4F_compress(); avoid saving src content within tmp buffer as future dictionary */ 110 unsigned reserved[3]; 111 } LZ4F_compressOptions_t; 112 113 /* Resource Management */ 114 115 #define LZ4F_VERSION 100 116 LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_compressionContext_t* LZ4F_compressionContextPtr, unsigned version); 117 LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_compressionContext_t LZ4F_compressionContext); 118 /* LZ4F_createCompressionContext() : 119 * The first thing to do is to create a compressionContext object, which will be used in all compression operations. 120 * This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure. 121 * The version provided MUST be LZ4F_VERSION. It is intended to track potential version differences between different binaries. 122 * The function will provide a pointer to a fully allocated LZ4F_compressionContext_t object. 123 * If the result LZ4F_errorCode_t is not zero, there was an error during context creation. 124 * Object can release its memory using LZ4F_freeCompressionContext(); 125 */ 126 127 128 /* Compression */ 129 130 size_t LZ4F_compressBegin(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const LZ4F_preferences_t* preferencesPtr); 131 /* LZ4F_compressBegin() : 132 * will write the frame header into dstBuffer. 133 * dstBuffer must be large enough to accommodate a header (dstMaxSize). Maximum header size is 19 bytes. 134 * The LZ4F_preferences_t structure is optional : you can provide NULL as argument, all preferences will then be set to default. 135 * The result of the function is the number of bytes written into dstBuffer for the header 136 * or an error code (can be tested using LZ4F_isError()) 137 */ 138 139 size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr); 140 /* LZ4F_compressBound() : 141 * Provides the minimum size of Dst buffer given srcSize to handle worst case situations. 142 * preferencesPtr is optional : you can provide NULL as argument, all preferences will then be set to default. 143 * Note that different preferences will produce in different results. 144 */ 145 146 size_t LZ4F_compressUpdate(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* compressOptionsPtr); 147 /* LZ4F_compressUpdate() 148 * LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary. 149 * The most important rule is that dstBuffer MUST be large enough (dstMaxSize) to ensure compression completion even in worst case. 150 * If this condition is not respected, LZ4F_compress() will fail (result is an errorCode) 151 * You can get the minimum value of dstMaxSize by using LZ4F_compressBound() 152 * The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. 153 * The result of the function is the number of bytes written into dstBuffer : it can be zero, meaning input data was just buffered. 154 * The function outputs an error code if it fails (can be tested using LZ4F_isError()) 155 */ 156 157 size_t LZ4F_flush(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const LZ4F_compressOptions_t* compressOptionsPtr); 158 /* LZ4F_flush() 159 * Should you need to create compressed data immediately, without waiting for a block to be filled, 160 * you can call LZ4_flush(), which will immediately compress any remaining data buffered within compressionContext. 161 * The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. 162 * The result of the function is the number of bytes written into dstBuffer 163 * (it can be zero, this means there was no data left within compressionContext) 164 * The function outputs an error code if it fails (can be tested using LZ4F_isError()) 165 */ 166 167 size_t LZ4F_compressEnd(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const LZ4F_compressOptions_t* compressOptionsPtr); 168 /* LZ4F_compressEnd() 169 * When you want to properly finish the compressed frame, just call LZ4F_compressEnd(). 170 * It will flush whatever data remained within compressionContext (like LZ4_flush()) 171 * but also properly finalize the frame, with an endMark and a checksum. 172 * The result of the function is the number of bytes written into dstBuffer (necessarily >= 4 (endMark size)) 173 * The function outputs an error code if it fails (can be tested using LZ4F_isError()) 174 * The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. 175 * compressionContext can then be used again, starting with LZ4F_compressBegin(). 176 */ 177 178 179 /*********************************** 180 * Decompression functions 181 * *********************************/ 182 183 typedef void* LZ4F_decompressionContext_t; 184 185 typedef struct { 186 unsigned stableDst; /* guarantee that decompressed data will still be there on next function calls (avoid storage into tmp buffers) */ 187 unsigned reserved[3]; 188 } LZ4F_decompressOptions_t; 189 190 191 /* Resource management */ 192 193 LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_decompressionContext_t* ctxPtr, unsigned version); 194 LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_decompressionContext_t ctx); 195 /* LZ4F_createDecompressionContext() : 196 * The first thing to do is to create a decompressionContext object, which will be used in all decompression operations. 197 * This is achieved using LZ4F_createDecompressionContext(). 198 * The version provided MUST be LZ4F_VERSION. It is intended to track potential version differences between different binaries. 199 * The function will provide a pointer to a fully allocated and initialized LZ4F_decompressionContext_t object. 200 * If the result LZ4F_errorCode_t is not OK_NoError, there was an error during context creation. 201 * Object can release its memory using LZ4F_freeDecompressionContext(); 202 */ 203 204 205 /* Decompression */ 206 207 size_t LZ4F_getFrameInfo(LZ4F_decompressionContext_t ctx, 208 LZ4F_frameInfo_t* frameInfoPtr, 209 const void* srcBuffer, size_t* srcSizePtr); 210 /* LZ4F_getFrameInfo() 211 * This function decodes frame header information, such as blockSize. 212 * It is optional : you could start by calling directly LZ4F_decompress() instead. 213 * The objective is to extract header information without starting decompression, typically for allocation purposes. 214 * LZ4F_getFrameInfo() can also be used *after* starting decompression, on a valid LZ4F_decompressionContext_t. 215 * The number of bytes read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value). 216 * You are expected to resume decompression from where it stopped (srcBuffer + *srcSizePtr) 217 * The function result is an hint of how many srcSize bytes LZ4F_decompress() expects for next call, 218 * or an error code which can be tested using LZ4F_isError(). 219 */ 220 221 size_t LZ4F_decompress(LZ4F_decompressionContext_t ctx, 222 void* dstBuffer, size_t* dstSizePtr, 223 const void* srcBuffer, size_t* srcSizePtr, 224 const LZ4F_decompressOptions_t* optionsPtr); 225 /* LZ4F_decompress() 226 * Call this function repetitively to regenerate data compressed within srcBuffer. 227 * The function will attempt to decode *srcSizePtr bytes from srcBuffer, into dstBuffer of maximum size *dstSizePtr. 228 * 229 * The number of bytes regenerated into dstBuffer will be provided within *dstSizePtr (necessarily <= original value). 230 * 231 * The number of bytes read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value). 232 * If number of bytes read is < number of bytes provided, then decompression operation is not completed. 233 * It typically happens when dstBuffer is not large enough to contain all decoded data. 234 * LZ4F_decompress() must be called again, starting from where it stopped (srcBuffer + *srcSizePtr) 235 * The function will check this condition, and refuse to continue if it is not respected. 236 * 237 * dstBuffer is supposed to be flushed between each call to the function, since its content will be overwritten. 238 * dst arguments can be changed at will with each consecutive call to the function. 239 * 240 * The function result is an hint of how many srcSize bytes LZ4F_decompress() expects for next call. 241 * Schematically, it's the size of the current (or remaining) compressed block + header of next block. 242 * Respecting the hint provides some boost to performance, since it does skip intermediate buffers. 243 * This is just a hint, you can always provide any srcSize you want. 244 * When a frame is fully decoded, the function result will be 0. (no more data expected) 245 * If decompression failed, function result is an error code, which can be tested using LZ4F_isError(). 246 */ 247 248 249 250 #if defined (__cplusplus) 251 } 252 #endif 253