1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mfbt/lz4.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,276 @@
1.4 +/*
1.5 + LZ4 - Fast LZ compression algorithm
1.6 + Header File
1.7 + Copyright (C) 2011-2014, Yann Collet.
1.8 + BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
1.9 +
1.10 + Redistribution and use in source and binary forms, with or without
1.11 + modification, are permitted provided that the following conditions are
1.12 + met:
1.13 +
1.14 + * Redistributions of source code must retain the above copyright
1.15 + notice, this list of conditions and the following disclaimer.
1.16 + * Redistributions in binary form must reproduce the above
1.17 + copyright notice, this list of conditions and the following disclaimer
1.18 + in the documentation and/or other materials provided with the
1.19 + distribution.
1.20 +
1.21 + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.22 + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.23 + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.24 + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1.25 + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1.26 + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1.27 + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.28 + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.29 + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.30 + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1.31 + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.32 +
1.33 + You can contact the author at :
1.34 + - LZ4 source repository : http://code.google.com/p/lz4/
1.35 + - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
1.36 +*/
1.37 +#pragma once
1.38 +
1.39 +#if defined (__cplusplus)
1.40 +extern "C" {
1.41 +#endif
1.42 +
1.43 +
1.44 +/**************************************
1.45 + Version
1.46 +**************************************/
1.47 +#define LZ4_VERSION_MAJOR 1 /* for major interface/format changes */
1.48 +#define LZ4_VERSION_MINOR 2 /* for minor interface/format changes */
1.49 +#define LZ4_VERSION_RELEASE 0 /* for tweaks, bug-fixes, or development */
1.50 +
1.51 +
1.52 +/**************************************
1.53 + Tuning parameter
1.54 +**************************************/
1.55 +/*
1.56 + * LZ4_MEMORY_USAGE :
1.57 + * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
1.58 + * Increasing memory usage improves compression ratio
1.59 + * Reduced memory usage can improve speed, due to cache effect
1.60 + * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
1.61 + */
1.62 +#define LZ4_MEMORY_USAGE 14
1.63 +
1.64 +
1.65 +/**************************************
1.66 + Simple Functions
1.67 +**************************************/
1.68 +
1.69 +int LZ4_compress (const char* source, char* dest, int inputSize);
1.70 +int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxOutputSize);
1.71 +
1.72 +/*
1.73 +LZ4_compress() :
1.74 + Compresses 'inputSize' bytes from 'source' into 'dest'.
1.75 + Destination buffer must be already allocated,
1.76 + and must be sized to handle worst cases situations (input data not compressible)
1.77 + Worst case size evaluation is provided by function LZ4_compressBound()
1.78 + inputSize : Max supported value is LZ4_MAX_INPUT_VALUE
1.79 + return : the number of bytes written in buffer dest
1.80 + or 0 if the compression fails
1.81 +
1.82 +LZ4_decompress_safe() :
1.83 + compressedSize : is obviously the source size
1.84 + maxOutputSize : is the size of the destination buffer, which must be already allocated.
1.85 + return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize)
1.86 + If the destination buffer is not large enough, decoding will stop and output an error code (<0).
1.87 + If the source stream is detected malformed, the function will stop decoding and return a negative result.
1.88 + This function is protected against buffer overflow exploits :
1.89 + it never writes outside of output buffer, and never reads outside of input buffer.
1.90 + Therefore, it is protected against malicious data packets.
1.91 +*/
1.92 +
1.93 +
1.94 +/*
1.95 +Note :
1.96 + Should you prefer to explicitly allocate compression-table memory using your own allocation method,
1.97 + use the streaming functions provided below, simply reset the memory area between each call to LZ4_compress_continue()
1.98 +*/
1.99 +
1.100 +
1.101 +/**************************************
1.102 + Advanced Functions
1.103 +**************************************/
1.104 +#define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */
1.105 +#define LZ4_COMPRESSBOUND(isize) ((unsigned int)(isize) > (unsigned int)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
1.106 +
1.107 +/*
1.108 +LZ4_compressBound() :
1.109 + Provides the maximum size that LZ4 may output in a "worst case" scenario (input data not compressible)
1.110 + primarily useful for memory allocation of output buffer.
1.111 + macro is also provided when result needs to be evaluated at compilation (such as stack memory allocation).
1.112 +
1.113 + isize : is the input size. Max supported value is LZ4_MAX_INPUT_SIZE
1.114 + return : maximum output size in a "worst case" scenario
1.115 + or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
1.116 +*/
1.117 +int LZ4_compressBound(int isize);
1.118 +
1.119 +
1.120 +/*
1.121 +LZ4_compress_limitedOutput() :
1.122 + Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
1.123 + If it cannot achieve it, compression will stop, and result of the function will be zero.
1.124 + This function never writes outside of provided output buffer.
1.125 +
1.126 + inputSize : Max supported value is LZ4_MAX_INPUT_VALUE
1.127 + maxOutputSize : is the size of the destination buffer (which must be already allocated)
1.128 + return : the number of bytes written in buffer 'dest'
1.129 + or 0 if the compression fails
1.130 +*/
1.131 +int LZ4_compress_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
1.132 +
1.133 +
1.134 +/*
1.135 +LZ4_decompress_fast() :
1.136 + originalSize : is the original and therefore uncompressed size
1.137 + return : the number of bytes read from the source buffer (in other words, the compressed size)
1.138 + If the source stream is malformed, the function will stop decoding and return a negative result.
1.139 + Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
1.140 + note : This function is a bit faster than LZ4_decompress_safe()
1.141 + It provides fast decompression and fully respect memory boundaries for properly formed compressed data.
1.142 + It does not provide full protection against intentionnally modified data stream.
1.143 + Use this function in a trusted environment (data to decode comes from a trusted source).
1.144 +*/
1.145 +int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
1.146 +
1.147 +
1.148 +/*
1.149 +LZ4_decompress_safe_partial() :
1.150 + This function decompress a compressed block of size 'compressedSize' at position 'source'
1.151 + into output buffer 'dest' of size 'maxOutputSize'.
1.152 + The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
1.153 + reducing decompression time.
1.154 + return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize)
1.155 + Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
1.156 + Always control how many bytes were decoded.
1.157 + If the source stream is detected malformed, the function will stop decoding and return a negative result.
1.158 + This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
1.159 +*/
1.160 +int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxOutputSize);
1.161 +
1.162 +
1.163 +/***********************************************
1.164 + Experimental Streaming Compression Functions
1.165 +***********************************************/
1.166 +
1.167 +#define LZ4_STREAMSIZE_U32 ((1 << (LZ4_MEMORY_USAGE-2)) + 8)
1.168 +#define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U32 * sizeof(unsigned int))
1.169 +/*
1.170 + * LZ4_stream_t
1.171 + * information structure to track an LZ4 stream.
1.172 + * important : set this structure content to zero before first use !
1.173 + */
1.174 +typedef struct { unsigned int table[LZ4_STREAMSIZE_U32]; } LZ4_stream_t;
1.175 +
1.176 +/*
1.177 + * If you prefer dynamic allocation methods,
1.178 + * LZ4_createStream
1.179 + * provides a pointer (void*) towards an initialized LZ4_stream_t structure.
1.180 + * LZ4_free just frees it.
1.181 + */
1.182 +void* LZ4_createStream();
1.183 +int LZ4_free (void* LZ4_stream);
1.184 +
1.185 +
1.186 +/*
1.187 + * LZ4_loadDict
1.188 + * Use this function to load a static dictionary into LZ4_stream.
1.189 + * Any previous data will be forgotten, only 'dictionary' will remain in memory.
1.190 + * Loading a size of 0 is allowed (same effect as init).
1.191 + * Return : 1 if OK, 0 if error
1.192 + */
1.193 +int LZ4_loadDict (void* LZ4_stream, const char* dictionary, int dictSize);
1.194 +
1.195 +/*
1.196 + * LZ4_compress_continue
1.197 + * Compress data block 'source', using blocks compressed before as dictionary to improve compression ratio
1.198 + * Previous data blocks are assumed to still be present at their previous location.
1.199 + */
1.200 +int LZ4_compress_continue (void* LZ4_stream, const char* source, char* dest, int inputSize);
1.201 +
1.202 +/*
1.203 + * LZ4_compress_limitedOutput_continue
1.204 + * Same as before, but also specify a maximum target compressed size (maxOutputSize)
1.205 + * If objective cannot be met, compression exits, and returns a zero.
1.206 + */
1.207 +int LZ4_compress_limitedOutput_continue (void* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize);
1.208 +
1.209 +/*
1.210 + * LZ4_saveDict
1.211 + * If previously compressed data block is not guaranteed to remain at its previous memory location
1.212 + * save it into a safe place (char* safeBuffer)
1.213 + * Note : you don't need to call LZ4_loadDict() afterwards,
1.214 + * dictionary is immediately usable, you can therefore call again LZ4_compress_continue()
1.215 + * Return : 1 if OK, 0 if error
1.216 + * Note : any dictSize > 64 KB will be interpreted as 64KB.
1.217 + */
1.218 +int LZ4_saveDict (void* LZ4_stream, char* safeBuffer, int dictSize);
1.219 +
1.220 +
1.221 +/************************************************
1.222 + Experimental Streaming Decompression Functions
1.223 +************************************************/
1.224 +
1.225 +#define LZ4_STREAMDECODESIZE_U32 4
1.226 +#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U32 * sizeof(unsigned int))
1.227 +/*
1.228 + * LZ4_streamDecode_t
1.229 + * information structure to track an LZ4 stream.
1.230 + * important : set this structure content to zero before first use !
1.231 + */
1.232 +typedef struct { unsigned int table[LZ4_STREAMDECODESIZE_U32]; } LZ4_streamDecode_t;
1.233 +
1.234 +/*
1.235 + * If you prefer dynamic allocation methods,
1.236 + * LZ4_createStreamDecode()
1.237 + * provides a pointer (void*) towards an initialized LZ4_streamDecode_t structure.
1.238 + * LZ4_free just frees it.
1.239 + */
1.240 +void* LZ4_createStreamDecode();
1.241 +int LZ4_free (void* LZ4_stream); /* yes, it's the same one as for compression */
1.242 +
1.243 +/*
1.244 +*_continue() :
1.245 + These decoding functions allow decompression of multiple blocks in "streaming" mode.
1.246 + Previously decoded blocks must still be available at the memory position where they were decoded.
1.247 + If it's not possible, save the relevant part of decoded data into a safe buffer,
1.248 + and indicate where it stands using LZ4_setDictDecode()
1.249 +*/
1.250 +int LZ4_decompress_safe_continue (void* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize);
1.251 +int LZ4_decompress_fast_continue (void* LZ4_streamDecode, const char* source, char* dest, int originalSize);
1.252 +
1.253 +/*
1.254 + * LZ4_setDictDecode
1.255 + * Use this function to instruct where to find the dictionary.
1.256 + * This function can be used to specify a static dictionary,
1.257 + * or to instruct where to find some previously decoded data saved into a different memory space.
1.258 + * Setting a size of 0 is allowed (same effect as no dictionary).
1.259 + * Return : 1 if OK, 0 if error
1.260 + */
1.261 +int LZ4_setDictDecode (void* LZ4_streamDecode, const char* dictionary, int dictSize);
1.262 +
1.263 +
1.264 +/*
1.265 +Advanced decoding functions :
1.266 +*_usingDict() :
1.267 + These decoding functions work the same as
1.268 + a combination of LZ4_setDictDecode() followed by LZ4_decompress_x_continue()
1.269 + all together into a single function call.
1.270 + It doesn't use nor update an LZ4_streamDecode_t structure.
1.271 +*/
1.272 +int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize);
1.273 +int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize);
1.274 +
1.275 +
1.276 +
1.277 +#if defined (__cplusplus)
1.278 +}
1.279 +#endif
