diff options
| -rw-r--r-- | include/linux/lz4.h | 762 | ||||
| -rw-r--r-- | lib/lz4/Makefile | 2 | ||||
| -rw-r--r-- | lib/lz4/lz4_compress.c | 1161 | ||||
| -rw-r--r-- | lib/lz4/lz4_decompress.c | 705 | ||||
| -rw-r--r-- | lib/lz4/lz4defs.h | 338 | ||||
| -rw-r--r-- | lib/lz4/lz4hc_compress.c | 867 |
6 files changed, 2758 insertions, 1077 deletions
diff --git a/include/linux/lz4.h b/include/linux/lz4.h index 6b784c59f321..1b0f8ca0f9c8 100644 --- a/include/linux/lz4.h +++ b/include/linux/lz4.h @@ -1,87 +1,717 @@ -#ifndef __LZ4_H__ -#define __LZ4_H__ -/* - * LZ4 Kernel Interface +/* LZ4 Kernel Interface * * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com> + * Copyright (C) 2016, Sven Schmidt <4sschmid@informatik.uni-hamburg.de> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. + * + * This file is based on the original header file + * for LZ4 - Fast LZ compression algorithm. + * + * LZ4 - Fast LZ compression algorithm + * Copyright (C) 2011-2016, Yann Collet. + * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * You can contact the author at : + * - LZ4 homepage : http://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 */ -#define LZ4_MEM_COMPRESS (16384) -#define LZ4HC_MEM_COMPRESS (262144 + (2 * sizeof(unsigned char *))) +#ifndef __LZ4_H__ +#define __LZ4_H__ + +#include <linux/types.h> +#include <linux/string.h> /* memset, memcpy */ + +/*-************************************************************************ + * CONSTANTS + **************************************************************************/ /* - * lz4_compressbound() - * Provides the maximum size that LZ4 may output in a "worst case" scenario - * (input data not compressible) + * LZ4_MEMORY_USAGE : + * Memory usage formula : N->2^N Bytes + * (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) + * Increasing memory usage improves compression ratio + * Reduced memory usage can improve speed, due to cache effect + * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */ -static inline size_t lz4_compressbound(size_t isize) +#define LZ4_MEMORY_USAGE 14 + +#define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */ +#define LZ4_COMPRESSBOUND(isize) (\ + (unsigned int)(isize) > (unsigned int)LZ4_MAX_INPUT_SIZE \ + ? 0 \ + : (isize) + ((isize)/255) + 16) + +#define LZ4_ACCELERATION_DEFAULT 1 +#define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2) +#define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE) +#define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) + +#define LZ4HC_MIN_CLEVEL 3 +#define LZ4HC_DEFAULT_CLEVEL 9 +#define LZ4HC_MAX_CLEVEL 16 + +#define LZ4HC_DICTIONARY_LOGSIZE 16 +#define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE) +#define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1) +#define LZ4HC_HASH_LOG (LZ4HC_DICTIONARY_LOGSIZE - 1) +#define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG) +#define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1) + +/*-************************************************************************ + * STREAMING CONSTANTS AND STRUCTURES + **************************************************************************/ +#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE - 3)) + 4) +#define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long)) + +#define LZ4_STREAMHCSIZE 262192 +#define LZ4_STREAMHCSIZE_SIZET (262192 / sizeof(size_t)) + +#define LZ4_STREAMDECODESIZE_U64 4 +#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * \ + sizeof(unsigned long long)) + +/* + * LZ4_stream_t - information structure to track an LZ4 stream. + */ +typedef struct { + uint32_t hashTable[LZ4_HASH_SIZE_U32]; + uint32_t currentOffset; + uint32_t initCheck; + const uint8_t *dictionary; + uint8_t *bufferStart; + uint32_t dictSize; +} LZ4_stream_t_internal; +typedef union { + unsigned long long table[LZ4_STREAMSIZE_U64]; + LZ4_stream_t_internal internal_donotuse; +} LZ4_stream_t; + +/* + * LZ4_streamHC_t - information structure to track an LZ4HC stream. + */ +typedef struct { + unsigned int hashTable[LZ4HC_HASHTABLESIZE]; + unsigned short chainTable[LZ4HC_MAXD]; + /* next block to continue on current prefix */ + const unsigned char *end; + /* All index relative to this position */ + const unsigned char *base; + /* alternate base for extDict */ + const unsigned char *dictBase; + /* below that point, need extDict */ + unsigned int dictLimit; + /* below that point, no more dict */ + unsigned int lowLimit; + /* index from which to continue dict update */ + unsigned int nextToUpdate; + unsigned int compressionLevel; +} LZ4HC_CCtx_internal; +typedef union { + size_t table[LZ4_STREAMHCSIZE_SIZET]; + LZ4HC_CCtx_internal internal_donotuse; +} LZ4_streamHC_t; + +/* + * LZ4_streamDecode_t - information structure to track an + * LZ4 stream during decompression. + * + * init this structure using LZ4_setStreamDecode (or memset()) before first use + */ +typedef struct { + const uint8_t *externalDict; + size_t extDictSize; + const uint8_t *prefixEnd; + size_t prefixSize; +} LZ4_streamDecode_t_internal; +typedef union { + unsigned long long table[LZ4_STREAMDECODESIZE_U64]; + LZ4_streamDecode_t_internal internal_donotuse; +} LZ4_streamDecode_t; + +/*-************************************************************************ + * SIZE OF STATE + **************************************************************************/ +#define LZ4_MEM_COMPRESS LZ4_STREAMSIZE +#define LZ4HC_MEM_COMPRESS LZ4_STREAMHCSIZE + +/*-************************************************************************ + * Compression Functions + **************************************************************************/ + +/** + * LZ4_compressBound() - Max. output size in worst case szenarios + * @isize: Size of the input data + * + * Return: Max. size LZ4 may output in a "worst case" szenario + * (data not compressible) + */ +static inline int LZ4_compressBound(size_t isize) { - return isize + (isize / 255) + 16; + return LZ4_COMPRESSBOUND(isize); } -/* - * lz4_compress() - * src : source address of the original data - * src_len : size of the original data - * dst : output buffer address of the compressed data - * This requires 'dst' of size LZ4_COMPRESSBOUND. - * dst_len : is the output size, which is returned after compress done - * workmem : address of the working memory. - * This requires 'workmem' of size LZ4_MEM_COMPRESS. - * return : Success if return 0 - * Error if return (< 0) - * note : Destination buffer and workmem must be already allocated with - * the defined size. - */ -int lz4_compress(const unsigned char *src, size_t src_len, - unsigned char *dst, size_t *dst_len, void *wrkmem); - - /* - * lz4hc_compress() - * src : source address of the original data - * src_len : size of the original data - * dst : output buffer address of the compressed data - * This requires 'dst' of size LZ4_COMPRESSBOUND. - * dst_len : is the output size, which is returned after compress done - * workmem : address of the working memory. - * This requires 'workmem' of size LZ4HC_MEM_COMPRESS. - * return : Success if return 0 - * Error if return (< 0) - * note : Destination buffer and workmem must be already allocated with - * the defined size. - */ -int lz4hc_compress(const unsigned char *src, size_t src_len, - unsigned char *dst, size_t *dst_len, void *wrkmem); +/** + * lz4_compressbound() - For backwards compatibility; see LZ4_compressBound + * @isize: Size of the input data + * + * Return: Max. size LZ4 may output in a "worst case" szenario + * (data not compressible) + */ +static inline int lz4_compressbound(size_t isize) +{ + return LZ4_COMPRESSBOUND(isize); +} + +/** + * LZ4_compress_default() - Compress data from source to dest + * @source: source address of the original data + * @dest: output buffer address of the compressed data + * @inputSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE + * @maxOutputSize: full or partial size of buffer 'dest' + * which must be already allocated + * @wrkmem: address of the working memory. + * This requires 'workmem' of LZ4_MEM_COMPRESS. + * + * Compresses 'sourceSize' bytes from buffer 'source' + * into already allocated 'dest' buffer of size 'maxOutputSize'. + * Compression is guaranteed to succeed if + * 'maxOutputSize' >= LZ4_compressBound(inputSize). + * It also runs faster, so it's a recommended setting. + * If the function cannot compress 'source' into a more limited 'dest' budget, + * compression stops *immediately*, and the function result is zero. + * As a consequence, 'dest' content is not valid. + * + * Return: Number of bytes written into buffer 'dest' + * (necessarily <= maxOutputSize) or 0 if compression fails + */ +int LZ4_compress_default(const char *source, char *dest, int inputSize, + int maxOutputSize, void *wrkmem); + +/** + * LZ4_compress_fast() - As LZ4_compress_default providing an acceleration param + * @source: source address of the original data + * @dest: output buffer address of the compressed data + * @inputSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE + * @maxOutputSize: full or partial size of buffer 'dest' + * which must be already allocated + * @acceleration: acceleration factor + * @wrkmem: address of the working memory. + * This requires 'workmem' of LZ4_MEM_COMPRESS. + * + * Same as LZ4_compress_default(), but allows to select an "acceleration" + * factor. The larger the acceleration value, the faster the algorithm, + * but also the lesser the compression. It's a trade-off. It can be fine tuned, + * with each successive value providing roughly +~3% to speed. + * An acceleration value of "1" is the same as regular LZ4_compress_default() + * Values <= 0 will be replaced by LZ4_ACCELERATION_DEFAULT, which is 1. + * + * Return: Number of bytes written into buffer 'dest' + * (necessarily <= maxOutputSize) or 0 if compression fails + */ +int LZ4_compress_fast(const char *source, char *dest, int inputSize, + int maxOutputSize, int acceleration, void *wrkmem); + +/** + * LZ4_compress_destSize() - Compress as much data as possible + * from source to dest + * @source: source address of the original data + * @dest: output buffer address of the compressed data + * @sourceSizePtr: will be modified to indicate how many bytes where read + * from 'source' to fill 'dest'. New value is necessarily <= old value. + * @targetDestSize: Size of buffer 'dest' which must be already allocated + * @wrkmem: address of the working memory. + * This requires 'workmem' of LZ4_MEM_COMPRESS. + * + * Reverse the logic, by compressing as much data as possible + * from 'source' buffer into already allocated buffer 'dest' + * of size 'targetDestSize'. + * This function either compresses the entire 'source' content into 'dest' + * if it's large enough, or fill 'dest' buffer completely with as much data as + * possible from 'source'. + * + * Return: Number of bytes written into 'dest' (necessarily <= targetDestSize) + * or 0 if compression fails + */ +int LZ4_compress_destSize(const char *source, char *dest, int *sourceSizePtr, + int targetDestSize, void *wrkmem); /* - * lz4_decompress() - * src : source address of the compressed data - * src_len : is the input size, whcih is returned after decompress done - * dest : output buffer address of the decompressed data - * actual_dest_len: is the size of uncompressed data, supposing it's known - * return : Success if return 0 - * Error if return (< 0) - * note : Destination buffer must be already allocated. - * slightly faster than lz4_decompress_unknownoutputsize() + * lz4_compress() - For backward compatibility, see LZ4_compress_default + * @src: source address of the original data + * @src_len: size of the original data + * @dst: output buffer address of the compressed data. This requires 'dst' + * of size LZ4_COMPRESSBOUND + * @dst_len: is the output size, which is returned after compress done + * @workmem: address of the working memory. + * + * Return: Success if return 0, Error if return < 0 */ -int lz4_decompress(const unsigned char *src, size_t *src_len, - unsigned char *dest, size_t actual_dest_len); +int lz4_compress(const unsigned char *src, size_t src_len, unsigned char *dst, + size_t *dst_len, void *wrkmem); + +/*-************************************************************************ + * Decompression Functions + **************************************************************************/ + +/** + * LZ4_decompress_fast() - Decompresses data from 'source' into 'dest' + * @source: source address of the compressed data + * @dest: output buffer address of the uncompressed data + * which must be already allocated with 'originalSize' bytes + * @originalSize: is the original and therefore uncompressed size + * + * Decompresses data from 'source' into 'dest'. + * This function fully respect memory boundaries for properly formed + * compressed data. + * It is a bit faster than LZ4_decompress_safe(). + * However, it does not provide any protection against intentionally + * modified data stream (malicious input). + * Use this function in trusted environment only + * (data to decode comes from a trusted source). + * + * Return: number of bytes read from the source buffer + * or a negative result if decompression fails. + */ +int LZ4_decompress_fast(const char *source, char *dest, int originalSize); + +/** + * LZ4_decompress_safe() - Decompression protected against buffer overflow + * @source: source address of the compressed data + * @dest: output buffer address of the uncompressed data + * which must be already allocated + * @compressedSize: is the precise full size of the compressed block + * @maxDecompressedSize: is the size of 'dest' buffer + * + * Decompresses data fom 'source' into 'dest'. + * If the source stream is detected malformed, the function will + * stop decoding and return a negative result. + * This function is protected against buffer overflow exploits, + * including malicious data packets. It never writes outside output buffer, + * nor reads outside input buffer. + * + * Return: number of bytes decompressed into destination buffer + * (necessarily <= maxDecompressedSize) + * or a negative result in case of error + */ +int LZ4_decompress_safe(const char *source, char *dest, int compressedSize, + int maxDecompressedSize); + +/** + * LZ4_decompress_safe_partial() - Decompress a block of size 'compressedSize' + * at position 'source' into buffer 'dest' + * @source: source address of the compressed data + * @dest: output buffer address of the decompressed data which must be + * already allocated + * @compressedSize: is the precise full size of the compressed block. + * @targetOutputSize: the decompression operation will try + * to stop as soon as 'targetOutputSize' has been reached + * @maxDecompressedSize: is the size of destination buffer + * + * This function decompresses a compressed block of size 'compressedSize' + * at position 'source' into destination buffer 'dest' + * of size 'maxDecompressedSize'. + * The function tries to stop decompressing operation as soon as + * 'targetOutputSize' has been reached, reducing decompression time. + * This function never writes outside of output buffer, + * and never reads outside of input buffer. + * It is therefore protected against malicious data packets. + * + * Return: the number of bytes decoded in the destination buffer + * (necessarily <= maxDecompressedSize) + * or a negative result in case of error + * + */ +int LZ4_decompress_safe_partial(const char *source, char *dest, + int compressedSize, int targetOutputSize, int maxDecompressedSize); /* - * lz4_decompress_unknownoutputsize() - * src : source address of the compressed data - * src_len : is the input size, therefore the compressed size - * dest : output buffer address of the decompressed data - * dest_len: is the max size of the destination buffer, which is - * returned with actual size of decompressed data after - * decompress done - * return : Success if return 0 - * Error if return (< 0) - * note : Destination buffer must be already allocated. + * lz4_decompress_unknownoutputsize() - For backwards compatibility, + * see LZ4_decompress_safe + * @src: source address of the compressed data + * @src_len: is the input size, therefore the compressed size + * @dest: output buffer address of the decompressed data + * which must be already allocated + * @dest_len: is the max size of the destination buffer, which is + * returned with actual size of decompressed data after decompress done + * + * Return: Success if return 0, Error if return (< 0) */ int lz4_decompress_unknownoutputsize(const unsigned char *src, size_t src_len, - unsigned char *dest, size_t *dest_len); + unsigned char *dest, size_t *dest_len); + +/** + * lz4_decompress() - For backwards cocmpatibility, see LZ4_decompress_fast + * @src: source address of the compressed data + * @src_len: is the input size, which is returned after decompress done + * @dest: output buffer address of the decompressed data, + * which must be already allocated + * @actual_dest_len: is the size of uncompressed data, supposing it's known + * + * Return: Success if return 0, Error if return (< 0) + */ +int lz4_decompress(const unsigned char *src, size_t *src_len, + unsigned char *dest, size_t actual_dest_len); + +/*-************************************************************************ + * LZ4 HC Compression + **************************************************************************/ + +/** + * LZ4_compress_HC() - Compress data from `src` into `dst`, using HC algorithm + * @src: source address of the original data + * @dst: output buffer address of the compressed data + * @srcSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE + * @dstCapacity: full or partial size of buffer 'dst', + * which must be already allocated + * @compressionLevel: Recommended values are between 4 and 9, although any + * value between 1 and LZ4HC_MAX_CLEVEL will work. + * Values >LZ4HC_MAX_CLEVEL behave the same as 16. + * @wrkmem: address of the working memory. + * This requires 'wrkmem' of size LZ4HC_MEM_COMPRESS. + * + * Compress data from 'src' into 'dst', using the more powerful + * but slower "HC" algorithm. Compression is guaranteed to succeed if + * `dstCapacity >= LZ4_compressBound(srcSize) + * + * Return : the number of bytes written into 'dst' or 0 if compression fails. + */ +int LZ4_compress_HC(const char *src, char *dst, int srcSize, int dstCapacity, + int compressionLevel, void *wrkmem); + +/** + * lz4hc_compress() - For backwards compatibility, see LZ4_compress_HC + * @src: source address of the original data + * @src_len: size of the original data + * @dst: output buffer address of the compressed data. This requires 'dst' + * of size LZ4_COMPRESSBOUND. + * @dst_len: is the output size, which is returned after compress done + * @wrkmem: address of the working memory. + * This requires 'workmem' of size LZ4HC_MEM_COMPRESS. + * + * Return : Success if return 0, Error if return (< 0) + */ +int lz4hc_compress(const unsigned char *src, size_t src_len, unsigned char *dst, + size_t *dst_len, void *wrkmem); + +/** + * LZ4_resetStreamHC() - Init an allocated 'LZ4_streamHC_t' structure + * @streamHCPtr: pointer to the 'LZ4_streamHC_t' structure + * @compressionLevel: Recommended values are between 4 and 9, although any + * value between 1 and LZ4HC_MAX_CLEVEL will work. + * Values >LZ4HC_MAX_CLEVEL behave the same as 16. + * + * An LZ4_streamHC_t structure can be allocated once + * and re-used multiple times. + * Use this function to init an allocated `LZ4_streamHC_t` structure + * and start a new compression. + */ +void LZ4_resetStreamHC(LZ4_streamHC_t *streamHCPtr, int compressionLevel); + +/** + * LZ4_loadDictHC() - Load a static dictionary into LZ4_streamHC + * @streamHCPtr: pointer to the LZ4HC_stream_t + * @dictionary: dictionary to load + * @dictSize: size of dictionary + * + * Use this function to load a static dictionary into LZ4HC_stream. + * Any previous data will be forgotten, only 'dictionary' + * will remain in memory. + * Loading a size of 0 is allowed. + * + * Return : dictionary size, in bytes (necessarily <= 64 KB) + */ +int LZ4_loadDictHC(LZ4_streamHC_t *streamHCPtr, const char *dictionary, + int dictSize); + +/** + * LZ4_compress_HC_continue() - Compress 'src' using data from previously + * compressed blocks as a dictionary using the HC algorithm + * @streamHCPtr: Pointer to the previous 'LZ4_streamHC_t' structure + * @src: source address of the original data + * @dst: output buffer address of the compressed data, + * which must be already allocated + * @srcSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE + * @maxDstSize: full or partial size of buffer 'dest' + * which must be already allocated + * + * These functions compress data in successive blocks of any size, using + * previous blocks as dictionary. One key assumption is that previous + * blocks (up to 64 KB) remain read-accessible while + * compressing next blocks. There is an exception for ring buffers, + * which can be smaller than 64 KB. + * Ring buffers scenario is automatically detected and handled by + * LZ4_compress_HC_continue(). + * Before starting compression, state must be properly initialized, + * using LZ4_resetStreamHC(). + * A first "fictional block" can then be designated as + * initial dictionary, using LZ4_loadDictHC() (Optional). + * Then, use LZ4_compress_HC_continue() + * to compress each successive block. Previous memory blocks + * (including initial dictionary when present) must remain accessible + * and unmodified during compression. + * 'dst' buffer should be sized to handle worst case scenarios, using + * LZ4_compressBound(), to ensure operation success. + * If, for any reason, previous data blocks can't be preserved unmodified + * in memory during next compression block, + * you must save it to a safer memory space, using LZ4_saveDictHC(). + * Return value of LZ4_saveDictHC() is the size of dictionary + * effectively saved into 'safeBuffer'. + * + * Return: Number of bytes written into buffer 'dst' or 0 if compression fails + */ +int LZ4_compress_HC_continue(LZ4_streamHC_t *streamHCPtr, const char *src, + char *dst, int srcSize, int maxDstSize); + +/** + * LZ4_saveDictHC() - Save static dictionary from LZ4HC_stream + * @streamHCPtr: pointer to the 'LZ4HC_stream_t' structure + * @safeBuffer: buffer to save dictionary to, must be already allocated + * @maxDictSize: size of 'safeBuffer' + * + * If previously compressed data block is not guaranteed + * to remain available at its memory location, + * save it into a safer place (char *safeBuffer). + * Note : you don't need to call LZ4_loadDictHC() afterwards, + * dictionary is immediately usable, you can therefore call + * LZ4_compress_HC_continue(). + * + * Return : saved dictionary size in bytes (necessarily <= maxDictSize), + * or 0 if error. + */ +int LZ4_saveDictHC(LZ4_streamHC_t *streamHCPtr, char *safeBuffer, + int maxDictSize); + +/*-********************************************* + * Streaming Compression Functions + ***********************************************/ + +/** + * LZ4_resetStream() - Init an allocated 'LZ4_stream_t' structure + * @LZ4_stream: pointer to the 'LZ4_stream_t' structure + * + * An LZ4_stream_t structure can be allocated once + * and re-used multiple times. + * Use this function to init an allocated `LZ4_stream_t` structure + * and start a new compression. + */ +void LZ4_resetStream(LZ4_stream_t *LZ4_stream); + +/** + * LZ4_loadDict() - Load a static dictionary into LZ4_stream + * @streamPtr: pointer to the LZ4_stream_t + * @dictionary: dictionary to load + * @dictSize: size of dictionary + * + * Use this function to load a static dictionary into LZ4_stream. + * Any previous data will be forgotten, only 'dictionary' + * will remain in memory. + * Loading a size of 0 is allowed. + * + * Return : dictionary size, in bytes (necessarily <= 64 KB) + */ +int LZ4_loadDict(LZ4_stream_t *streamPtr, const char *dictionary, + int dictSize); + +/** + * LZ4_saveDict() - Save static dictionary from LZ4_stream + * @streamPtr: pointer to the 'LZ4_stream_t' structure + * @safeBuffer: buffer to save dictionary to, must be already allocated + * @dictSize: size of 'safeBuffer' + * + * If previously compressed data block is not guaranteed + * to remain available at its memory location, + * save it into a safer place (char *safeBuffer). + * Note : you don't need to call LZ4_loadDict() afterwards, + * dictionary is immediately usable, you can therefore call + * LZ4_compress_fast_continue(). + * + * Return : saved dictionary size in bytes (necessarily <= dictSize), + * or 0 if error. + */ +int LZ4_saveDict(LZ4_stream_t *streamPtr, char *safeBuffer, int dictSize); + +/** + * LZ4_compress_fast_continue() - Compress 'src' using data from previously + * compressed blocks as a dictionary + * @streamPtr: Pointer to the previous 'LZ4_stream_t' structure + * @src: source address of the original data + * @dst: output buffer address of the compressed data, + * which must be already allocated + * @srcSize: size of the input data. Max supported value is LZ4_MAX_INPUT_SIZE + * @maxDstSize: full or partial size of buffer 'dest' + * which must be already allocated + * @acceleration: acceleration factor + * + * Compress buffer content 'src', using data from previously compressed blocks + * as dictionary to improve compression ratio. + * Important : Previous data blocks are assumed to still + * be present and unmodified ! + * If maxDstSize >= LZ4_compressBound(srcSize), + * compression is guaranteed to succeed, and runs faster. + * + * Return: Number of bytes written into buffer 'dst' or 0 if compression fails + */ +int LZ4_compress_fast_continue(LZ4_stream_t *streamPtr, const char *src, + char *dst, int srcSize, int maxDstSize, int acceleration); + +/** + * LZ4_setStreamDecode() - Instruct where to find dictionary + * @LZ4_streamDecode: the 'LZ4_streamDecode_t' structure + * @dictionary: dictionary to use + * @dictSize: size of dictionary + * + * Use this function to instruct where to find the dictionary. + * Setting a size of 0 is allowed (same effect as reset). + * + * Return: 1 if OK, 0 if error + */ +int LZ4_setStreamDecode(LZ4_streamDecode_t *LZ4_streamDecode, + const char *dictionary, int dictSize); + +/** + * LZ4_decompress_fast_continue() - Decompress blocks in streaming mode + * @LZ4_streamDecode: the 'LZ4_streamDecode_t' structure + * @source: source address of the compressed data + * @dest: output buffer address of the uncompressed data + * which must be already allocated + * @compressedSize: is the precise full size of the compressed block + * @maxDecompressedSize: is the size of 'dest' buffer + * + * These decoding function allows decompression of multiple blocks + * in "streaming" mode. + * Previously decoded blocks *must* remain available at the memory position + * where they were decoded (up to 64 KB) + * In the case of a ring buffers, decoding buffer must be either : + * - Exactly same size as encoding buffer, with same update rule + * (block boundaries at same positions) In which case, + * the decoding & encoding ring buffer can have any size, + * including very small ones ( < 64 KB). + * - Larger than encoding buffer, by a minimum of maxBlockSize more bytes. + * maxBlockSize is implementation dependent. + * It's the maximum size you intend to compress into a single block. + * In which case, encoding and decoding buffers do not need + * to be synchronized, and encoding ring buffer can have any size, + * including small ones ( < 64 KB). + * - _At least_ 64 KB + 8 bytes + maxBlockSize. + * In which case, encoding and decoding buffers do not need to be + * synchronized, and encoding ring buffer can have any size, + * including larger than decoding buffer. W + * Whenever these conditions are not possible, save the last 64KB of decoded + * data into a safe buffer, and indicate where it is saved + * using LZ4_setStreamDecode() + * + * Return: number of bytes decompressed into destination buffer + * (necessarily <= maxDecompressedSize) + * or a negative result in case of error + */ +int LZ4_decompress_safe_continue(LZ4_streamDecode_t *LZ4_streamDecode, + const char *source, char *dest, int compressedSize, + int maxDecompressedSize); + +/** + * LZ4_decompress_fast_continue() - Decompress blocks in streaming mode + * @LZ4_streamDecode: the 'LZ4_streamDecode_t' structure + * @source: source address of the compressed data + * @dest: output buffer address of the uncompressed data + * which must be already allocated with 'originalSize' bytes + * @originalSize: is the original and therefore uncompressed size + * + * These decoding function allows decompression of multiple blocks + * in "streaming" mode. + * Previously decoded blocks *must* remain available at the memory position + * where they were decoded (up to 64 KB) + * In the case of a ring buffers, decoding buffer must be either : + * - Exactly same size as encoding buffer, with same update rule + * (block boundaries at same positions) In which case, + * the decoding & encoding ring buffer can have any size, + * including very small ones ( < 64 KB). + * - Larger than encoding buffer, by a minimum of maxBlockSize more bytes. + * maxBlockSize is implementation dependent. + * It's the maximum size you intend to compress into a single block. + * In which case, encoding and decoding buffers do not need + * to be synchronized, and encoding ring buffer can have any size, + * including small ones ( < 64 KB). + * - _At least_ 64 KB + 8 bytes + maxBlockSize. + * In which case, encoding and decoding buffers do not need to be + * synchronized, and encoding ring buffer can have any size, + * including larger than decoding buffer. W + * Whenever these conditions are not possible, save the last 64KB of decoded + * data into a safe buffer, and indicate where it is saved + * using LZ4_setStreamDecode() + * + * Return: number of bytes decompressed into destination buffer + * (necessarily <= maxDecompressedSize) + * or a negative result in case of error + */ +int LZ4_decompress_fast_continue(LZ4_streamDecode_t *LZ4_streamDecode, + const char *source, char *dest, int originalSize); + +/** + * LZ4_decompress_safe_usingDict() - Same as LZ4_setStreamDecode() + * followed by LZ4_decompress_safe_continue() + * @source: source address of the compressed data + * @dest: output buffer address of the uncompressed data + * which must be already allocated + * @compressedSize: is the precise full size of the compressed block + * @maxDecompressedSize: is the size of 'dest' buffer + * @dictStart: pointer to the start of the dictionary in memory + * @dictSize: size of dictionary + * + * These decoding function works the same as + * a combination of LZ4_setStreamDecode() followed by + * LZ4_decompress_safe_continue() + * It is stand-alone, and don'tn eed a LZ4_streamDecode_t structure. + * + * Return: number of bytes decompressed into destination buffer + * (necessarily <= maxDecompressedSize) + * or a negative result in case of error + */ +int LZ4_decompress_safe_usingDict(const char *source, char *dest, + int compressedSize, int maxDecompressedSize, const char *dictStart, + int dictSize); + +/** + * LZ4_decompress_fast_usingDict() - Same as LZ4_setStreamDecode() + * followed by LZ4_decompress_fast_continue() + * @source: source address of the compressed data + * @dest: output buffer address of the uncompressed data + * which must be already allocated with 'originalSize' bytes + * @originalSize: is the original and therefore uncompressed size + * @dictStart: pointer to the start of the dictionary in memory + * @dictSize: size of dictionary + * + * These decoding function works the same as + * a combination of LZ4_setStreamDecode() followed by + * LZ4_decompress_safe_continue() + * It is stand-alone, and don'tn eed a LZ4_streamDecode_t structure. + * + * Return: number of bytes decompressed into destination buffer + * (necessarily <= maxDecompressedSize) + * or a negative result in case of error + */ +int LZ4_decompress_fast_usingDict(const char *source, char *dest, + int originalSize, const char *dictStart, int dictSize); + #endif diff --git a/lib/lz4/Makefile b/lib/lz4/Makefile index 8085d04e9309..f7b113271d13 100644 --- a/lib/lz4/Makefile +++ b/lib/lz4/Makefile @@ -1,3 +1,5 @@ +ccflags-y += -O3 + obj-$(CONFIG_LZ4_COMPRESS) += lz4_compress.o obj-$(CONFIG_LZ4HC_COMPRESS) += lz4hc_compress.o obj-$(CONFIG_LZ4_DECOMPRESS) += lz4_decompress.o diff --git a/lib/lz4/lz4_compress.c b/lib/lz4/lz4_compress.c index 28321d8f75ef..53f313f05185 100644 --- a/lib/lz4/lz4_compress.c +++ b/lib/lz4/lz4_compress.c @@ -1,19 +1,16 @@ /* * LZ4 - Fast LZ compression algorithm - * Copyright (C) 2011-2012, Yann Collet. - * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) - + * Copyright (C) 2011 - 2016, Yann Collet. + * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php) * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: - * - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. - * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR @@ -25,417 +22,939 @@ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - * * You can contact the author at : - * - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html - * - LZ4 source repository : http://code.google.com/p/lz4/ + * - LZ4 homepage : http://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 * - * Changed for kernel use by: - * Chanho Min <chanho.min@lge.com> + * Changed for kernel usage by: + * Sven Schmidt <4sschmid@informatik.uni-hamburg.de> */ +/*-************************************ + * Dependencies + **************************************/ +#include <linux/lz4.h> +#include "lz4defs.h" #include <linux/module.h> #include <linux/kernel.h> -#include <linux/lz4.h> #include <asm/unaligned.h> -#include "lz4defs.h" -/* - * LZ4_compressCtx : - * ----------------- - * Compress 'isize' bytes from 'source' into an output buffer 'dest' of - * maximum size 'maxOutputSize'. * If it cannot achieve it, compression - * will stop, and result of the function will be zero. - * return : the number of bytes written in buffer 'dest', or 0 if the - * compression fails - */ -static inline int lz4_compressctx(void *ctx, - const char *source, - char *dest, - int isize, - int maxoutputsize) +static const int LZ4_minLength = (MFLIMIT + 1); +static const int LZ4_64Klimit = ((64 * KB) + (MFLIMIT - 1)); + +/*-****************************** + * Compression functions + ********************************/ +static FORCE_INLINE U32 LZ4_hash4( + U32 sequence, + tableType_t const tableType) { - HTYPE *hashtable = (HTYPE *)ctx; - const u8 *ip = (u8 *)source; -#if LZ4_ARCH64 - const BYTE * const base = ip; + if (tableType == byU16) + return ((sequence * 2654435761U) + >> ((MINMATCH * 8) - (LZ4_HASHLOG + 1))); + else + return ((sequence * 2654435761U) + >> ((MINMATCH * 8) - LZ4_HASHLOG)); +} + +static FORCE_INLINE U32 LZ4_hash5( + U64 sequence, + tableType_t const tableType) +{ + const U32 hashLog = (tableType == byU16) + ? LZ4_HASHLOG + 1 + : LZ4_HASHLOG; + +#if LZ4_LITTLE_ENDIAN + static const U64 prime5bytes = 889523592379ULL; + + return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog)); #else - const int base = 0; + static const U64 prime8bytes = 11400714785074694791ULL; + + return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog)); #endif - const u8 *anchor = ip; - const u8 *const iend = ip + isize; - const u8 *const mflimit = iend - MFLIMIT; - #define MATCHLIMIT (iend - LASTLITERALS) - - u8 *op = (u8 *) dest; - u8 *const oend = op + maxoutputsize; - int length; - const int skipstrength = SKIPSTRENGTH; - u32 forwardh; - int lastrun; - - /* Init */ - if (isize < MINLENGTH) - goto _last_literals; +} + +static FORCE_INLINE U32 LZ4_hashPosition( + const void *p, + tableType_t const tableType) +{ +#if LZ4_ARCH64 + if (tableType == byU32) + return LZ4_hash5(LZ4_read_ARCH(p), tableType); +#endif + + return LZ4_hash4(LZ4_read32(p), tableType); +} + +static void LZ4_putPositionOnHash( + const BYTE *p, + U32 h, + void *tableBase, + tableType_t const tableType, + const BYTE *srcBase) +{ + switch (tableType) { + case byPtr: + { + const BYTE **hashTable = (const BYTE **)tableBase; + + hashTable[h] = p; + return; + } + case byU32: + { + U32 *hashTable = (U32 *) tableBase; + + hashTable[h] = (U32)(p - srcBase); + return; + } + case byU16: + { + U16 *hashTable = (U16 *) tableBase; + + hashTable[h] = (U16)(p - srcBase); + return; + } + } +} + +static FORCE_INLINE void LZ4_putPosition( + const BYTE *p, + void *tableBase, + tableType_t tableType, + const BYTE *srcBase) +{ + U32 const h = LZ4_hashPosition(p, tableType); + + LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase); +} + +static const BYTE *LZ4_getPositionOnHash( + U32 h, + void *tableBase, + tableType_t tableType, + const BYTE *srcBase) +{ + if (tableType == byPtr) { + const BYTE **hashTable = (const BYTE **) tableBase; + + return hashTable[h]; + } + + if (tableType == byU32) { + const U32 * const hashTable = (U32 *) tableBase; + + return hashTable[h] + srcBase; + } + + { + /* default, to ensure a return */ + const U16 * const hashTable = (U16 *) tableBase; + + return hashTable[h] + srcBase; + } +} + +static FORCE_INLINE const BYTE *LZ4_getPosition( + const BYTE *p, + void *tableBase, + tableType_t tableType, + const BYTE *srcBase) +{ + U32 const h = LZ4_hashPosition(p, tableType); + + return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase); +} + - memset((void *)hashtable, 0, LZ4_MEM_COMPRESS); +/* + * LZ4_compress_generic() : + * inlined, to ensure branches are decided at compilation time + */ +static FORCE_INLINE int LZ4_compress_generic( + LZ4_stream_t_internal * const dictPtr, + const char * const source, + char * const dest, + const int inputSize, + const int maxOutputSize, + const limitedOutput_directive outputLimited, + const tableType_t tableType, + const dict_directive dict, + const dictIssue_directive dictIssue, + const U32 acceleration) +{ + const BYTE *ip = (const BYTE *) source; + const BYTE *base; + const BYTE *lowLimit; + const BYTE * const lowRefLimit = ip - dictPtr->dictSize; + const BYTE * const dictionary = dictPtr->dictionary; + const BYTE * const dictEnd = dictionary + dictPtr->dictSize; + const size_t dictDelta = dictEnd - (const BYTE *)source; + const BYTE *anchor = (const BYTE *) source; + const BYTE * const iend = ip + inputSize; + const BYTE * const mflimit = iend - MFLIMIT; + const BYTE * const matchlimit = iend - LASTLITERALS; + + BYTE *op = (BYTE *) dest; + BYTE * const olimit = op + maxOutputSize; + + U32 forwardH; + size_t refDelta = 0; + + /* Init conditions */ + if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) { + /* Unsupported inputSize, too large (or negative) */ + return 0; + } + + switch (dict) { + case noDict: + default: + base = (const BYTE *)source; + lowLimit = (const BYTE *)source; + break; + case withPrefix64k: + base = (const BYTE *)source - dictPtr->currentOffset; + lowLimit = (const BYTE *)source - dictPtr->dictSize; + break; + case usingExtDict: + base = (const BYTE *)source - dictPtr->currentOffset; + lowLimit = (const BYTE *)source; + break; + } + + if ((tableType == byU16) + && (inputSize >= LZ4_64Klimit)) { + /* Size too large (not within 64K limit) */ + return 0; + } + + if (inputSize < LZ4_minLength) { + /* Input too small, no compression (all literals) */ + goto _last_literals; + } /* First Byte */ - hashtable[LZ4_HASH_VALUE(ip)] = ip - base; + LZ4_putPosition(ip, dictPtr->hashTable, tableType, base); ip++; - forwardh = LZ4_HASH_VALUE(ip); + forwardH = LZ4_hashPosition(ip, tableType); /* Main Loop */ - for (;;) { - int findmatchattempts = (1U << skipstrength) + 3; - const u8 *forwardip = ip; - const u8 *ref; - u8 *token; + for ( ; ; ) { + const BYTE *match; + BYTE *token; /* Find a match */ - do { - u32 h = forwardh; - int step = findmatchattempts++ >> skipstrength; - ip = forwardip; - forwardip = ip + step; - - if (unlikely(forwardip > mflimit)) - goto _last_literals; - - forwardh = LZ4_HASH_VALUE(forwardip); - ref = base + hashtable[h]; - hashtable[h] = ip - base; - } while ((ref < ip - MAX_DISTANCE) || (A32(ref) != A32(ip))); + { + const BYTE *forwardIp = ip; + unsigned int step = 1; + unsigned int searchMatchNb = acceleration << LZ4_SKIPTRIGGER; + + do { + U32 const h = forwardH; + + ip = forwardIp; + forwardIp += step; + step = (searchMatchNb++ >> LZ4_SKIPTRIGGER); + + if (unlikely(forwardIp > mflimit)) + goto _last_literals; + + match = LZ4_getPositionOnHash(h, + dictPtr->hashTable, + tableType, base); + + if (dict == usingExtDict) { + if (match < (const BYTE *)source) { + refDelta = dictDelta; + lowLimit = dictionary; + } else { + refDelta = 0; + lowLimit = (const BYTE *)source; + } } + + forwardH = LZ4_hashPosition(forwardIp, + tableType); + + LZ4_putPositionOnHash(ip, h, dictPtr->hashTable, + tableType, base); + } while (((dictIssue == dictSmall) + ? (match < lowRefLimit) + : 0) + || ((tableType == byU16) + ? 0 + : (match + MAX_DISTANCE < ip)) + || (LZ4_read32(match + refDelta) + != LZ4_read32(ip))); + } /* Catch up */ - while ((ip > anchor) && (ref > (u8 *)source) && - unlikely(ip[-1] == ref[-1])) { + while (((ip > anchor) & (match + refDelta > lowLimit)) + && (unlikely(ip[-1] == match[refDelta - 1]))) { ip--; - ref--; + match--; } - /* Encode Literal length */ - length = (int)(ip - anchor); - token = op++; - /* check output limit */ - if (unlikely(op + length + (2 + 1 + LASTLITERALS) + - (length >> 8) > oend)) - return 0; + /* Encode Literals */ + { + unsigned const int litLength = (unsigned int)(ip - anchor); - if (length >= (int)RUN_MASK) { - int len; - *token = (RUN_MASK << ML_BITS); - len = length - RUN_MASK; - for (; len > 254 ; len -= 255) - *op++ = 255; - *op++ = (u8)len; - } else - *token = (length << ML_BITS); + token = op++; + + if ((outputLimited) && + /* Check output buffer overflow */ + (unlikely(op + litLength + + (2 + 1 + LASTLITERALS) + + (litLength / 255) > olimit))) + return 0; + + if (litLength >= RUN_MASK) { + int len = (int)litLength - RUN_MASK; + + *token = (RUN_MASK << ML_BITS); + + for (; len >= 255; len -= 255) + *op++ = 255; + *op++ = (BYTE)len; + } else + *token = (BYTE)(litLength << ML_BITS); + + /* Copy Literals */ + LZ4_wildCopy(op, anchor, op + litLength); + op += litLength; + } - /* Copy Literals */ - LZ4_BLINDCOPY(anchor, op, length); _next_match: /* Encode Offset */ - LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref)); + LZ4_writeLE16(op, (U16)(ip - match)); + op += 2; - /* Start Counting */ - ip += MINMATCH; - /* MinMatch verified */ - ref += MINMATCH; - anchor = ip; - while (likely(ip < MATCHLIMIT - (STEPSIZE - 1))) { - #if LZ4_ARCH64 - u64 diff = A64(ref) ^ A64(ip); - #else - u32 diff = A32(ref) ^ A32(ip); - #endif - if (!diff) { - ip += STEPSIZE; - ref += STEPSIZE; - continue; - } - ip += LZ4_NBCOMMONBYTES(diff); - goto _endcount; - } - #if LZ4_ARCH64 - if ((ip < (MATCHLIMIT - 3)) && (A32(ref) == A32(ip))) { - ip += 4; - ref += 4; - } - #endif - if ((ip < (MATCHLIMIT - 1)) && (A16(ref) == A16(ip))) { - ip += 2; - ref += 2; - } - if ((ip < MATCHLIMIT) && (*ref == *ip)) - ip++; -_endcount: /* Encode MatchLength */ - length = (int)(ip - anchor); - /* Check output limit */ - if (unlikely(op + (1 + LASTLITERALS) + (length >> 8) > oend)) - return 0; - if (length >= (int)ML_MASK) { - *token += ML_MASK; - length -= ML_MASK; - for (; length > 509 ; length -= 510) { - *op++ = 255; - *op++ = 255; - } - if (length > 254) { - length -= 255; - *op++ = 255; + { + unsigned int matchCode; + + if ((dict == usingExtDict) + && (lowLimit == dictionary)) { + const BYTE *limit; + + match += refDelta; + limit = ip + (dictEnd - match); + + if (limit > matchlimit) + limit = matchlimit; + + matchCode = LZ4_count(ip + MINMATCH, + match + MINMATCH, limit); + + ip += MINMATCH + matchCode; + + if (ip == limit) { + unsigned const int more = LZ4_count(ip, + (const BYTE *)source, + matchlimit); + + matchCode += more; + ip += more; + } + } else { + matchCode = LZ4_count(ip + MINMATCH, + match + MINMATCH, matchlimit); + ip += MINMATCH + matchCode; } - *op++ = (u8)length; - } else - *token += length; + + if (outputLimited && + /* Check output buffer overflow */ + (unlikely(op + + (1 + LASTLITERALS) + + (matchCode >> 8) > olimit))) + return 0; + + if (matchCode >= ML_MASK) { + *token += ML_MASK; + matchCode -= ML_MASK; + LZ4_write32(op, 0xFFFFFFFF); + + while (matchCode >= 4 * 255) { + op += 4; + LZ4_write32(op, 0xFFFFFFFF); + matchCode -= 4 * 255; + } + + op += matchCode / 255; + *op++ = (BYTE)(matchCode % 255); + } else + *token += (BYTE)(matchCode); + } + + anchor = ip; /* Test end of chunk */ - if (ip > mflimit) { - anchor = ip; + if (ip > mflimit) break; - } /* Fill table */ - hashtable[LZ4_HASH_VALUE(ip-2)] = ip - 2 - base; + LZ4_putPosition(ip - 2, dictPtr->hashTable, tableType, base); /* Test next position */ - ref = base + hashtable[LZ4_HASH_VALUE(ip)]; - hashtable[LZ4_HASH_VALUE(ip)] = ip - base; - if ((ref > ip - (MAX_DISTANCE + 1)) && (A32(ref) == A32(ip))) { + match = LZ4_getPosition(ip, dictPtr->hashTable, + tableType, base); + + if (dict == usingExtDict) { + if (match < (const BYTE *)source) { + refDelta = dictDelta; + lowLimit = dictionary; + } else { + refDelta = 0; + lowLimit = (const BYTE *)source; + } + } + + LZ4_putPosition(ip, dictPtr->hashTable, tableType, base); + + if (((dictIssue == dictSmall) ? (match >= lowRefLimit) : 1) + && (match + MAX_DISTANCE >= ip) + && (LZ4_read32(match + refDelta) == LZ4_read32(ip))) { token = op++; *token = 0; goto _next_match; } /* Prepare next loop */ - anchor = ip++; - forwardh = LZ4_HASH_VALUE(ip); + forwardH = LZ4_hashPosition(++ip, tableType); } _last_literals: /* Encode Last Literals */ - lastrun = (int)(iend - anchor); - if (((char *)op - dest) + lastrun + 1 - + ((lastrun + 255 - RUN_MASK) / 255) > (u32)maxoutputsize) - return 0; + { + size_t const lastRun = (size_t)(iend - anchor); - if (lastrun >= (int)RUN_MASK) { - *op++ = (RUN_MASK << ML_BITS); - lastrun -= RUN_MASK; - for (; lastrun > 254 ; lastrun -= 255) - *op++ = 255; - *op++ = (u8)lastrun; - } else - *op++ = (lastrun << ML_BITS); - memcpy(op, anchor, iend - anchor); - op += iend - anchor; + if ((outputLimited) && + /* Check output buffer overflow */ + ((op - (BYTE *)dest) + lastRun + 1 + + ((lastRun + 255 - RUN_MASK) / 255) > (U32)maxOutputSize)) + return 0; + + if (lastRun >= RUN_MASK) { + size_t accumulator = lastRun - RUN_MASK; + *op++ = RUN_MASK << ML_BITS; + for (; accumulator >= 255; accumulator -= 255) + *op++ = 255; + *op++ = (BYTE) accumulator; + } else { + *op++ = (BYTE)(lastRun << ML_BITS); + } + + memcpy(op, anchor, lastRun); + + op += lastRun; + } /* End */ - return (int)(((char *)op) - dest); + return (int) (((char *)op) - dest); } -static inline int lz4_compress64kctx(void *ctx, - const char *source, - char *dest, - int isize, - int maxoutputsize) +static int LZ4_compress_fast_extState( + void *state, + const char *source, + char *dest, + int inputSize, + int maxOutputSize, + int acceleration) { - u16 *hashtable = (u16 *)ctx; - const u8 *ip = (u8 *) source; - const u8 *anchor = ip; - const u8 *const base = ip; - const u8 *const iend = ip + isize; - const u8 *const mflimit = iend - MFLIMIT; - #define MATCHLIMIT (iend - LASTLITERALS) - - u8 *op = (u8 *) dest; - u8 *const oend = op + maxoutputsize; - int len, length; - const int skipstrength = SKIPSTRENGTH; - u32 forwardh; - int lastrun; - - /* Init */ - if (isize < MINLENGTH) - goto _last_literals; + LZ4_stream_t_internal *ctx = &((LZ4_stream_t *)state)->internal_donotuse; +#if LZ4_ARCH64 + const tableType_t tableType = byU32; +#else + const tableType_t tableType = byPtr; +#endif - memset((void *)hashtable, 0, LZ4_MEM_COMPRESS); + LZ4_resetStream((LZ4_stream_t *)state); + + if (acceleration < 1) + acceleration = LZ4_ACCELERATION_DEFAULT; + + if (maxOutputSize >= LZ4_COMPRESSBOUND(inputSize)) { + if (inputSize < LZ4_64Klimit) + return LZ4_compress_generic(ctx, source, + dest, inputSize, 0, + noLimit, byU16, noDict, + noDictIssue, acceleration); + else + return LZ4_compress_generic(ctx, source, + dest, inputSize, 0, + noLimit, tableType, noDict, + noDictIssue, acceleration); + } else { + if (inputSize < LZ4_64Klimit) + return LZ4_compress_generic(ctx, source, + dest, inputSize, + maxOutputSize, limitedOutput, byU16, noDict, + noDictIssue, acceleration); + else + return LZ4_compress_generic(ctx, source, + dest, inputSize, + maxOutputSize, limitedOutput, tableType, noDict, + noDictIssue, acceleration); + } +} + +int LZ4_compress_fast(const char *source, char *dest, int inputSize, + int maxOutputSize, int acceleration, void *wrkmem) +{ + return LZ4_compress_fast_extState(wrkmem, source, dest, inputSize, + maxOutputSize, acceleration); +} +EXPORT_SYMBOL(LZ4_compress_fast); + +int LZ4_compress_default(const char *source, char *dest, int inputSize, + int maxOutputSize, void *wrkmem) +{ + return LZ4_compress_fast(source, dest, inputSize, + maxOutputSize, LZ4_ACCELERATION_DEFAULT, wrkmem); +} +EXPORT_SYMBOL(LZ4_compress_default); + +/*-****************************** + * *_destSize() variant + ********************************/ +static int LZ4_compress_destSize_generic( + LZ4_stream_t_internal * const ctx, + const char * const src, + char * const dst, + int * const srcSizePtr, + const int targetDstSize, + const tableType_t tableType) +{ + const BYTE *ip = (const BYTE *) src; + const BYTE *base = (const BYTE *) src; + const BYTE *lowLimit = (const BYTE *) src; + const BYTE *anchor = ip; + const BYTE * const iend = ip + *srcSizePtr; + const BYTE * const mflimit = iend - MFLIMIT; + const BYTE * const matchlimit = iend - LASTLITERALS; + + BYTE *op = (BYTE *) dst; + BYTE * const oend = op + targetDstSize; + BYTE * const oMaxLit = op + targetDstSize - 2 /* offset */ + - 8 /* because 8 + MINMATCH == MFLIMIT */ - 1 /* token */; + BYTE * const oMaxMatch = op + targetDstSize + - (LASTLITERALS + 1 /* token */); + BYTE * const oMaxSeq = oMaxLit - 1 /* token */; + + U32 forwardH; + + /* Init conditions */ + /* Impossible to store anything */ + if (targetDstSize < 1) + return 0; + /* Unsupported input size, too large (or negative) */ + if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) + return 0; + /* Size too large (not within 64K limit) */ + if ((tableType == byU16) && (*srcSizePtr >= LZ4_64Klimit)) + return 0; + /* Input too small, no compression (all literals) */ + if (*srcSizePtr < LZ4_minLength) + goto _last_literals; /* First Byte */ - ip++; - forwardh = LZ4_HASH64K_VALUE(ip); + *srcSizePtr = 0; + LZ4_putPosition(ip, ctx->hashTable, tableType, base); + ip++; forwardH = LZ4_hashPosition(ip, tableType); /* Main Loop */ - for (;;) { - int findmatchattempts = (1U << skipstrength) + 3; - const u8 *forwardip = ip; - const u8 *ref; - u8 *token; + for ( ; ; ) { + const BYTE *match; + BYTE *token; /* Find a match */ - do { - u32 h = forwardh; - int step = findmatchattempts++ >> skipstrength; - ip = forwardip; - forwardip = ip + step; - - if (forwardip > mflimit) - goto _last_literals; - - forwardh = LZ4_HASH64K_VALUE(forwardip); - ref = base + hashtable[h]; - hashtable[h] = (u16)(ip - base); - } while (A32(ref) != A32(ip)); + { + const BYTE *forwardIp = ip; + unsigned int step = 1; + unsigned int searchMatchNb = 1 << LZ4_SKIPTRIGGER; + + do { + U32 h = forwardH; + + ip = forwardIp; + forwardIp += step; + step = (searchMatchNb++ >> LZ4_SKIPTRIGGER); + + if (unlikely(forwardIp > mflimit)) + goto _last_literals; + + match = LZ4_getPositionOnHash(h, ctx->hashTable, + tableType, base); + forwardH = LZ4_hashPosition(forwardIp, + tableType); + LZ4_putPositionOnHash(ip, h, + ctx->hashTable, tableType, + base); + + } while (((tableType == byU16) + ? 0 + : (match + MAX_DISTANCE < ip)) + || (LZ4_read32(match) != LZ4_read32(ip))); + } /* Catch up */ - while ((ip > anchor) && (ref > (u8 *)source) - && (ip[-1] == ref[-1])) { + while ((ip > anchor) + && (match > lowLimit) + && (unlikely(ip[-1] == match[-1]))) { ip--; - ref--; + match--; } /* Encode Literal length */ - length = (int)(ip - anchor); - token = op++; - /* Check output limit */ - if (unlikely(op + length + (2 + 1 + LASTLITERALS) - + (length >> 8) > oend)) - return 0; - if (length >= (int)RUN_MASK) { - *token = (RUN_MASK << ML_BITS); - len = length - RUN_MASK; - for (; len > 254 ; len -= 255) - *op++ = 255; - *op++ = (u8)len; - } else - *token = (length << ML_BITS); + { + unsigned int litLength = (unsigned int)(ip - anchor); - /* Copy Literals */ - LZ4_BLINDCOPY(anchor, op, length); + token = op++; + if (op + ((litLength + 240) / 255) + + litLength > oMaxLit) { + /* Not enough space for a last match */ + op--; + goto _last_literals; + } + if (litLength >= RUN_MASK) { + unsigned int len = litLength - RUN_MASK; + *token = (RUN_MASK<<ML_BITS); + for (; len >= 255; len -= 255) + *op++ = 255; + *op++ = (BYTE)len; + } else + *token = (BYTE)(litLength << ML_BITS); + + /* Copy Literals */ + LZ4_wildCopy(op, anchor, op + litLength); + op += litLength; + } _next_match: /* Encode Offset */ - LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref)); + LZ4_writeLE16(op, (U16)(ip - match)); op += 2; - /* Start Counting */ - ip += MINMATCH; - /* MinMatch verified */ - ref += MINMATCH; - anchor = ip; + /* Encode MatchLength */ + { + size_t matchLength = LZ4_count(ip + MINMATCH, + match + MINMATCH, matchlimit); - while (ip < MATCHLIMIT - (STEPSIZE - 1)) { - #if LZ4_ARCH64 - u64 diff = A64(ref) ^ A64(ip); - #else - u32 diff = A32(ref) ^ A32(ip); - #endif - - if (!diff) { - ip += STEPSIZE; - ref += STEPSIZE; - continue; + if (op + ((matchLength + 240)/255) > oMaxMatch) { + /* Match description too long : reduce it */ + matchLength = (15 - 1) + (oMaxMatch - op) * 255; } - ip += LZ4_NBCOMMONBYTES(diff); - goto _endcount; - } - #if LZ4_ARCH64 - if ((ip < (MATCHLIMIT - 3)) && (A32(ref) == A32(ip))) { - ip += 4; - ref += 4; - } - #endif - if ((ip < (MATCHLIMIT - 1)) && (A16(ref) == A16(ip))) { - ip += 2; - ref += 2; + ip += MINMATCH + matchLength; + + if (matchLength >= ML_MASK) { + *token += ML_MASK; + matchLength -= ML_MASK; + while (matchLength >= 255) { + matchLength -= 255; + *op++ = 255; + } + *op++ = (BYTE)matchLength; + } else + *token += (BYTE)(matchLength); } - if ((ip < MATCHLIMIT) && (*ref == *ip)) - ip++; -_endcount: - /* Encode MatchLength */ - len = (int)(ip - anchor); - /* Check output limit */ - if (unlikely(op + (1 + LASTLITERALS) + (len >> 8) > oend)) - return 0; - if (len >= (int)ML_MASK) { - *token += ML_MASK; - len -= ML_MASK; - for (; len > 509 ; len -= 510) { - *op++ = 255; - *op++ = 255; - } - if (len > 254) { - len -= 255; - *op++ = 255; - } - *op++ = (u8)len; - } else - *token += len; + anchor = ip; - /* Test end of chunk */ - if (ip > mflimit) { - anchor = ip; + /* Test end of block */ + if (ip > mflimit) + break; + if (op > oMaxSeq) break; - } /* Fill table */ - hashtable[LZ4_HASH64K_VALUE(ip-2)] = (u16)(ip - 2 - base); + LZ4_putPosition(ip - 2, ctx->hashTable, tableType, base); /* Test next position */ - ref = base + hashtable[LZ4_HASH64K_VALUE(ip)]; - hashtable[LZ4_HASH64K_VALUE(ip)] = (u16)(ip - base); - if (A32(ref) == A32(ip)) { - token = op++; - *token = 0; + match = LZ4_getPosition(ip, ctx->hashTable, tableType, base); + LZ4_putPosition(ip, ctx->hashTable, tableType, base); + + if ((match + MAX_DISTANCE >= ip) + && (LZ4_read32(match) == LZ4_read32(ip))) { + token = op++; *token = 0; goto _next_match; } /* Prepare next loop */ - anchor = ip++; - forwardh = LZ4_HASH64K_VALUE(ip); + forwardH = LZ4_hashPosition(++ip, tableType); } _last_literals: /* Encode Last Literals */ - lastrun = (int)(iend - anchor); - if (op + lastrun + 1 + (lastrun - RUN_MASK + 255) / 255 > oend) - return 0; - if (lastrun >= (int)RUN_MASK) { - *op++ = (RUN_MASK << ML_BITS); - lastrun -= RUN_MASK; - for (; lastrun > 254 ; lastrun -= 255) - *op++ = 255; - *op++ = (u8)lastrun; - } else - *op++ = (lastrun << ML_BITS); - memcpy(op, anchor, iend - anchor); - op += iend - anchor; + { + size_t lastRunSize = (size_t)(iend - anchor); + + if (op + 1 /* token */ + + ((lastRunSize + 240) / 255) /* litLength */ + + lastRunSize /* literals */ > oend) { + /* adapt lastRunSize to fill 'dst' */ + lastRunSize = (oend - op) - 1; + lastRunSize -= (lastRunSize + 240) / 255; + } + ip = anchor + lastRunSize; + + if (lastRunSize >= RUN_MASK) { + size_t accumulator = lastRunSize - RUN_MASK; + + *op++ = RUN_MASK << ML_BITS; + for (; accumulator >= 255; accumulator -= 255) + *op++ = 255; + *op++ = (BYTE) accumulator; + } else { + *op++ = (BYTE)(lastRunSize<<ML_BITS); + } + memcpy(op, anchor, lastRunSize); + op += lastRunSize; + } + /* End */ - return (int)(((char *)op) - dest); + *srcSizePtr = (int) (((const char *)ip) - src); + return (int) (((char *)op) - dst); } -int lz4_compress(const unsigned char *src, size_t src_len, - unsigned char *dst, size_t *dst_len, void *wrkmem) +static int LZ4_compress_destSize_extState( + LZ4_stream_t *state, + const char *src, + char *dst, + int *srcSizePtr, + int targetDstSize) { - int ret = -1; - int out_len = 0; +#if LZ4_ARCH64 + const tableType_t tableType = byU32; +#else + const tableType_t tableType = byPtr; +#endif - if (src_len < LZ4_64KLIMIT) - out_len = lz4_compress64kctx(wrkmem, src, dst, src_len, - lz4_compressbound(src_len)); - else - out_len = lz4_compressctx(wrkmem, src, dst, src_len, - lz4_compressbound(src_len)); + LZ4_resetStream(state); + + if (targetDstSize >= LZ4_COMPRESSBOUND(*srcSizePtr)) { + /* compression success is guaranteed */ + return LZ4_compress_fast_extState( + state, src, dst, *srcSizePtr, + targetDstSize, 1); + } else { + if (*srcSizePtr < LZ4_64Klimit) + return LZ4_compress_destSize_generic( + &state->internal_donotuse, + src, dst, srcSizePtr, + targetDstSize, byU16); + else + return LZ4_compress_destSize_generic( + &state->internal_donotuse, + src, dst, srcSizePtr, + targetDstSize, tableType); + } +} + + +int LZ4_compress_destSize( + const char *src, + char *dst, + int *srcSizePtr, + int targetDstSize, + void *wrkmem) +{ + return LZ4_compress_destSize_extState(wrkmem, src, dst, srcSizePtr, + targetDstSize); +} +EXPORT_SYMBOL(LZ4_compress_destSize); + +/*-****************************** + * Streaming functions + ********************************/ +void LZ4_resetStream(LZ4_stream_t *LZ4_stream) +{ + memset(LZ4_stream, 0, sizeof(LZ4_stream_t)); +} + +int LZ4_loadDict(LZ4_stream_t *LZ4_dict, + const char *dictionary, int dictSize) +{ + LZ4_stream_t_internal *dict = &LZ4_dict->internal_donotuse; + const BYTE *p = (const BYTE *)dictionary; + const BYTE * const dictEnd = p + dictSize; + const BYTE *base; + + if ((dict->initCheck) + || (dict->currentOffset > 1 * GB)) { + /* Uninitialized structure, or reuse overflow */ + LZ4_resetStream(LZ4_dict); + } + + if (dictSize < (int)HASH_UNIT) { + dict->dictionary = NULL; + dict->dictSize = 0; + return 0; + } + + if ((dictEnd - p) > 64 * KB) + p = dictEnd - 64 * KB; + dict->currentOffset += 64 * KB; + base = p - dict->currentOffset; + dict->dictionary = p; + dict->dictSize = (U32)(dictEnd - p); + dict->currentOffset += dict->dictSize; + + while (p <= dictEnd - HASH_UNIT) { + LZ4_putPosition(p, dict->hashTable, byU32, base); + p += 3; + } + + return dict->dictSize; +} +EXPORT_SYMBOL(LZ4_loadDict); + +static void LZ4_renormDictT(LZ4_stream_t_internal *LZ4_dict, + const BYTE *src) +{ + if ((LZ4_dict->currentOffset > 0x80000000) || + ((uptrval)LZ4_dict->currentOffset > (uptrval)src)) { + /* address space overflow */ + /* rescale hash table */ + U32 const delta = LZ4_dict->currentOffset - 64 * KB; + const BYTE *dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize; + int i; + + for (i = 0; i < LZ4_HASH_SIZE_U32; i++) { + if (LZ4_dict->hashTable[i] < delta) + LZ4_dict->hashTable[i] = 0; + else + LZ4_dict->hashTable[i] -= delta; + } + LZ4_dict->currentOffset = 64 * KB; + if (LZ4_dict->dictSize > 64 * KB) + LZ4_dict->dictSize = 64 * KB; + LZ4_dict->dictionary = dictEnd - LZ4_dict->dictSize; + } +} + +int LZ4_saveDict(LZ4_stream_t *LZ4_dict, char *safeBuffer, int dictSize) +{ + LZ4_stream_t_internal * const dict = &LZ4_dict->internal_donotuse; + const BYTE * const previousDictEnd = dict->dictionary + dict->dictSize; + + if ((U32)dictSize > 64 * KB) { + /* useless to define a dictionary > 64 * KB */ + dictSize = 64 * KB; + } + if ((U32)dictSize > dict->dictSize) + dictSize = dict->dictSize; + + memmove(safeBuffer, previousDictEnd - dictSize, dictSize); + + dict->dictionary = (const BYTE *)safeBuffer; + dict->dictSize = (U32)dictSize; + + return dictSize; +} +EXPORT_SYMBOL(LZ4_saveDict); + +int LZ4_compress_fast_continue(LZ4_stream_t *LZ4_stream, const char *source, + char *dest, int inputSize, int maxOutputSize, int acceleration) +{ + LZ4_stream_t_internal *streamPtr = &LZ4_stream->internal_donotuse; + const BYTE * const dictEnd = streamPtr->dictionary + + streamPtr->dictSize; + + const BYTE *smallest = (const BYTE *) source; + + if (streamPtr->initCheck) { + /* Uninitialized structure detected */ + return 0; + } + + if ((streamPtr->dictSize > 0) && (smallest > dictEnd)) + smallest = dictEnd; + + LZ4_renormDictT(streamPtr, smallest); + + if (acceleration < 1) + acceleration = LZ4_ACCELERATION_DEFAULT; - if (out_len < 0) - goto exit; + /* Check overlapping input/dictionary space */ + { + const BYTE *sourceEnd = (const BYTE *) source + inputSize; + + if ((sourceEnd > streamPtr->dictionary) + && (sourceEnd < dictEnd)) { + streamPtr->dictSize = (U32)(dictEnd - sourceEnd); + if (streamPtr->dictSize > 64 * KB) + streamPtr->dictSize = 64 * KB; + if (streamPtr->dictSize < 4) + streamPtr->dictSize = 0; + streamPtr->dictionary = dictEnd - streamPtr->dictSize; + } + } - *dst_len = out_len; + /* prefix mode : source data follows dictionary */ + if (dictEnd == (const BYTE *)source) { + int result; + + if ((streamPtr->dictSize < 64 * KB) && + (streamPtr->dictSize < streamPtr->currentOffset)) { + result = LZ4_compress_generic( + streamPtr, source, dest, inputSize, + maxOutputSize, limitedOutput, byU32, + withPrefix64k, dictSmall, acceleration); + } else { + result = LZ4_compress_generic( + streamPtr, source, dest, inputSize, + maxOutputSize, limitedOutput, byU32, + withPrefix64k, noDictIssue, acceleration); + } + streamPtr->dictSize += (U32)inputSize; + streamPtr->currentOffset += (U32)inputSize; + return result; + } - return 0; -exit: - return ret; + /* external dictionary mode */ + { + int result; + + if ((streamPtr->dictSize < 64 * KB) && + (streamPtr->dictSize < streamPtr->currentOffset)) { + result = LZ4_compress_generic( + streamPtr, source, dest, inputSize, + maxOutputSize, limitedOutput, byU32, + usingExtDict, dictSmall, acceleration); + } else { + result = LZ4_compress_generic( + streamPtr, source, dest, inputSize, + maxOutputSize, limitedOutput, byU32, + usingExtDict, noDictIssue, acceleration); + } + streamPtr->dictionary = (const BYTE *)source; + streamPtr->dictSize = (U32)inputSize; + streamPtr->currentOffset += (U32)inputSize; + return result; + } +} +EXPORT_SYMBOL(LZ4_compress_fast_continue); + +/*-****************************** + * For backwards compatibility + ********************************/ +int lz4_compress(const unsigned char *src, size_t src_len, unsigned char *dst, + size_t *dst_len, void *wrkmem) { + *dst_len = LZ4_compress_default(src, dst, src_len, + *dst_len, wrkmem); + + /* + * Prior lz4_compress will return -1 in case of error + * and 0 on success + * while new LZ4_compress_fast/default + * returns 0 in case of error + * and the output length on success + */ + if (!*dst_len) + return -1; + else + return 0; } EXPORT_SYMBOL(lz4_compress); diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c index 6d940c72b5fc..b5e00a19a7b4 100644 --- a/lib/lz4/lz4_decompress.c +++ b/lib/lz4/lz4_decompress.c @@ -1,25 +1,16 @@ /* - * LZ4 Decompressor for Linux kernel - * - * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com> - * - * Based on LZ4 implementation by Yann Collet. - * * LZ4 - Fast LZ compression algorithm - * Copyright (C) 2011-2012, Yann Collet. - * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) - * + * Copyright (C) 2011 - 2016, Yann Collet. + * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php) * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: - * - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. - * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR @@ -31,313 +22,529 @@ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * You can contact the author at : + * - LZ4 homepage : http://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 * - * You can contact the author at : - * - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html - * - LZ4 source repository : http://code.google.com/p/lz4/ + * Changed for kernel usage by: + * Sven Schmidt <4sschmid@informatik.uni-hamburg.de> */ -#ifndef STATIC +/*-************************************ + * Dependencies + **************************************/ +#include <linux/lz4.h> +#include "lz4defs.h" +#include <linux/init.h> #include <linux/module.h> #include <linux/kernel.h> -#endif -#include <linux/lz4.h> - #include <asm/unaligned.h> -#include "lz4defs.h" - -static const int dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0}; -#if LZ4_ARCH64 -static const int dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3}; -#endif - -static int lz4_uncompress(const char *source, char *dest, int osize) +/*-***************************** + * Decompression functions + *******************************/ +/* LZ4_decompress_generic() : + * This generic decompression function cover all use cases. + * It shall be instantiated several times, using different sets of directives + * Note that it is important this generic function is really inlined, + * in order to remove useless branches during compilation optimization. + */ +static FORCE_INLINE int LZ4_decompress_generic( + const char * const source, + char * const dest, + int inputSize, + /* + * If endOnInput == endOnInputSize, + * this value is the max size of Output Buffer. + */ + int outputSize, + /* endOnOutputSize, endOnInputSize */ + int endOnInput, + /* full, partial */ + int partialDecoding, + /* only used if partialDecoding == partial */ + int targetOutputSize, + /* noDict, withPrefix64k, usingExtDict */ + int dict, + /* == dest when no prefix */ + const BYTE * const lowPrefix, + /* only if dict == usingExtDict */ + const BYTE * const dictStart, + /* note : = 0 if noDict */ + const size_t dictSize + ) { + /* Local Variables */ const BYTE *ip = (const BYTE *) source; - const BYTE *ref; + const BYTE * const iend = ip + inputSize; + BYTE *op = (BYTE *) dest; - BYTE * const oend = op + osize; + BYTE * const oend = op + outputSize; BYTE *cpy; - unsigned token; - size_t length; + BYTE *oexit = op + targetOutputSize; + const BYTE * const lowLimit = lowPrefix - dictSize; + + const BYTE * const dictEnd = (const BYTE *)dictStart + dictSize; + const unsigned int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; + const int dec64table[] = { 0, 0, 0, -1, 0, 1, 2, 3 }; + const int safeDecode = (endOnInput == endOnInputSize); + const int checkOffset = ((safeDecode) && (dictSize < (int)(64 * KB))); + + /* Special cases */ + /* targetOutputSize too high => decode everything */ + if ((partialDecoding) && (oexit > oend - MFLIMIT)) + oexit = oend - MFLIMIT; + + /* Empty output buffer */ + if ((endOnInput) && (unlikely(outputSize == 0))) + return ((inputSize == 1) && (*ip == 0)) ? 0 : -1; + + if ((!endOnInput) && (unlikely(outputSize == 0))) + return (*ip == 0 ? 1 : -1); + + /* Main Loop : decode sequences */ while (1) { + size_t length; + const BYTE *match; + size_t offset; + + /* get literal length */ + unsigned int const token = *ip++; + + length = token>>ML_BITS; - /* get runlength */ - token = *ip++; - length = (token >> ML_BITS); if (length == RUN_MASK) { - size_t len; + unsigned int s; - len = *ip++; - for (; len == 255; length += 255) - len = *ip++; - if (unlikely(length > (size_t)(length + len))) + do { + s = *ip++; + length += s; + } while (likely(endOnInput + ? ip < iend - RUN_MASK + : 1) & (s == 255)); + + if ((safeDecode) + && unlikely( + (size_t)(op + length) < (size_t)(op))) { + /* overflow detection */ goto _output_error; - length += len; + } + if ((safeDecode) + && unlikely( + (size_t)(ip + length) < (size_t)(ip))) { + /* overflow detection */ + goto _output_error; + } } /* copy literals */ cpy = op + length; - if (unlikely(cpy > oend - COPYLENGTH)) { - /* - * Error: not enough place for another match - * (min 4) + 5 literals - */ - if (cpy != oend) - goto _output_error; + if (((endOnInput) && ((cpy > (partialDecoding ? oexit : oend - MFLIMIT)) + || (ip + length > iend - (2 + 1 + LASTLITERALS)))) + || ((!endOnInput) && (cpy > oend - WILDCOPYLENGTH))) { + if (partialDecoding) { + if (cpy > oend) { + /* + * Error : + * write attempt beyond end of output buffer + */ + goto _output_error; + } + if ((endOnInput) + && (ip + length > iend)) { + /* + * Error : + * read attempt beyond + * end of input buffer + */ + goto _output_error; + } + } else { + if ((!endOnInput) + && (cpy != oend)) { + /* + * Error : + * block decoding must + * stop exactly there + */ + goto _output_error; + } + if ((endOnInput) + && ((ip + length != iend) + || (cpy > oend))) { + /* + * Error : + * input must be consumed + */ + goto _output_error; + } + } memcpy(op, ip, length); ip += length; - break; /* EOF */ + op += length; + /* Necessarily EOF, due to parsing restrictions */ + break; } - LZ4_WILDCOPY(ip, op, cpy); - ip -= (op - cpy); + + LZ4_wildCopy(op, ip, cpy); + ip += length; op = cpy; /* get offset */ - LZ4_READ_LITTLEENDIAN_16(ref, cpy, ip); + offset = LZ4_readLE16(ip); ip += 2; + match = op - offset; - /* Error: offset create reference outside destination buffer */ - if (unlikely(ref < (BYTE *const) dest)) + if ((checkOffset) && (unlikely(match < lowLimit))) { + /* Error : offset outside buffers */ goto _output_error; + } + + /* costs ~1%; silence an msan warning when offset == 0 */ + LZ4_write32(op, (U32)offset); /* get matchlength */ length = token & ML_MASK; if (length == ML_MASK) { - for (; *ip == 255; length += 255) - ip++; - if (unlikely(length > (size_t)(length + *ip))) + unsigned int s; + + do { + s = *ip++; + + if ((endOnInput) && (ip > iend - LASTLITERALS)) + goto _output_error; + + length += s; + } while (s == 255); + + if ((safeDecode) + && unlikely( + (size_t)(op + length) < (size_t)op)) { + /* overflow detection */ goto _output_error; - length += *ip++; + } } - /* copy repeated sequence */ - if (unlikely((op - ref) < STEPSIZE)) { -#if LZ4_ARCH64 - int dec64 = dec64table[op - ref]; -#else - const int dec64 = 0; -#endif - op[0] = ref[0]; - op[1] = ref[1]; - op[2] = ref[2]; - op[3] = ref[3]; - op += 4; - ref += 4; - ref -= dec32table[op-ref]; - PUT4(ref, op); - op += STEPSIZE - 4; - ref -= dec64; + length += MINMATCH; + + /* check external dictionary */ + if ((dict == usingExtDict) && (match < lowPrefix)) { + if (unlikely(op + length > oend - LASTLITERALS)) { + /* doesn't respect parsing restriction */ + goto _output_error; + } + + if (length <= (size_t)(lowPrefix - match)) { + /* + * match can be copied as a single segment + * from external dictionary + */ + memmove(op, dictEnd - (lowPrefix - match), + length); + op += length; + } else { + /* + * match encompass external + * dictionary and current block + */ + size_t const copySize = (size_t)(lowPrefix - match); + size_t const restSize = length - copySize; + + memcpy(op, dictEnd - copySize, copySize); + op += copySize; + + if (restSize > (size_t)(op - lowPrefix)) { + /* overlap copy */ + BYTE * const endOfMatch = op + restSize; + const BYTE *copyFrom = lowPrefix; + + while (op < endOfMatch) + *op++ = *copyFrom++; + } else { + memcpy(op, lowPrefix, restSize); + op += restSize; + } + } + + continue; + } + + /* copy match within block */ + cpy = op + length; + + if (unlikely(offset < 8)) { + const int dec64 = dec64table[offset]; + + op[0] = match[0]; + op[1] = match[1]; + op[2] = match[2]; + op[3] = match[3]; + match += dec32table[offset]; + memcpy(op + 4, match, 4); + match -= dec64; } else { - LZ4_COPYSTEP(ref, op); + LZ4_copy8(op, match); + match += 8; } - cpy = op + length - (STEPSIZE - 4); - if (cpy > (oend - COPYLENGTH)) { - /* Error: request to write beyond destination buffer */ - if (cpy > oend) - goto _output_error; -#if LZ4_ARCH64 - if ((ref + COPYLENGTH) > oend) -#else - if ((ref + COPYLENGTH) > oend || - (op + COPYLENGTH) > oend) -#endif + op += 8; + + if (unlikely(cpy > oend - 12)) { + BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1); + + if (cpy > oend - LASTLITERALS) { + /* + * Error : last LASTLITERALS bytes + * must be literals (uncompressed) + */ goto _output_error; - LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH)); + } + + if (op < oCopyLimit) { + LZ4_wildCopy(op, match, oCopyLimit); + match += oCopyLimit - op; + op = oCopyLimit; + } + while (op < cpy) - *op++ = *ref++; - op = cpy; - /* - * Check EOF (should never happen, since last 5 bytes - * are supposed to be literals) - */ - if (op == oend) - goto _output_error; - continue; + *op++ = *match++; + } else { + LZ4_copy8(op, match); + + if (length > 16) + LZ4_wildCopy(op + 8, match + 8, cpy); } - LZ4_SECURECOPY(ref, op, cpy); + op = cpy; /* correction */ } + /* end of decoding */ - return (int) (((char *)ip) - source); + if (endOnInput) { + /* Nb of output bytes decoded */ + return (int) (((char *)op) - dest); + } else { + /* Nb of input bytes read */ + return (int) (((const char *)ip) - source); + } - /* write overflow error detected */ + /* Overflow error detected */ _output_error: return -1; } -static int lz4_uncompress_unknownoutputsize(const char *source, char *dest, - int isize, size_t maxoutputsize) +int LZ4_decompress_safe(const char *source, char *dest, + int compressedSize, int maxDecompressedSize) { - const BYTE *ip = (const BYTE *) source; - const BYTE *const iend = ip + isize; - const BYTE *ref; - + return LZ4_decompress_generic(source, dest, compressedSize, + maxDecompressedSize, endOnInputSize, full, 0, + noDict, (BYTE *)dest, NULL, 0); +} - BYTE *op = (BYTE *) dest; - BYTE * const oend = op + maxoutputsize; - BYTE *cpy; +int LZ4_decompress_safe_partial(const char *source, char *dest, + int compressedSize, int targetOutputSize, int maxDecompressedSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, + maxDecompressedSize, endOnInputSize, partial, + targetOutputSize, noDict, (BYTE *)dest, NULL, 0); +} - /* Main Loop */ - while (ip < iend) { +int LZ4_decompress_fast(const char *source, char *dest, int originalSize) +{ + return LZ4_decompress_generic(source, dest, 0, originalSize, + endOnOutputSize, full, 0, withPrefix64k, + (BYTE *)(dest - 64 * KB), NULL, 64 * KB); +} - unsigned token; - size_t length; +int LZ4_setStreamDecode(LZ4_streamDecode_t *LZ4_streamDecode, + const char *dictionary, int dictSize) +{ + LZ4_streamDecode_t_internal *lz4sd = (LZ4_streamDecode_t_internal *) LZ4_streamDecode; - /* get runlength */ - token = *ip++; - length = (token >> ML_BITS); - if (length == RUN_MASK) { - int s = 255; - while ((ip < iend) && (s == 255)) { - s = *ip++; - if (unlikely(length > (size_t)(length + s))) - goto _output_error; - length += s; - } - } - /* copy literals */ - cpy = op + length; - if ((cpy > oend - COPYLENGTH) || - (ip + length > iend - COPYLENGTH)) { - - if (cpy > oend) - goto _output_error;/* writes beyond buffer */ - - if (ip + length != iend) - goto _output_error;/* - * Error: LZ4 format requires - * to consume all input - * at this stage - */ - memcpy(op, ip, length); - op += length; - break;/* Necessarily EOF, due to parsing restrictions */ - } - LZ4_WILDCOPY(ip, op, cpy); - ip -= (op - cpy); - op = cpy; + lz4sd->prefixSize = (size_t) dictSize; + lz4sd->prefixEnd = (const BYTE *) dictionary + dictSize; + lz4sd->externalDict = NULL; + lz4sd->extDictSize = 0; + return 1; +} - /* get offset */ - LZ4_READ_LITTLEENDIAN_16(ref, cpy, ip); - ip += 2; - if (ref < (BYTE * const) dest) - goto _output_error; - /* - * Error : offset creates reference - * outside of destination buffer - */ +/* + * *_continue() : + * These decoding functions allow decompression of multiple blocks + * in "streaming" mode. + * Previously decoded blocks must still be available at the memory + * position where they were decoded. + * If it's not possible, save the relevant part of + * decoded data into a safe buffer, + * and indicate where it stands using LZ4_setStreamDecode() + */ +int LZ4_decompress_safe_continue(LZ4_streamDecode_t *LZ4_streamDecode, + const char *source, char *dest, int compressedSize, int maxOutputSize) +{ + LZ4_streamDecode_t_internal *lz4sd = &LZ4_streamDecode->internal_donotuse; + int result; + + if (lz4sd->prefixEnd == (BYTE *)dest) { + result = LZ4_decompress_generic(source, dest, + compressedSize, + maxOutputSize, + endOnInputSize, full, 0, + usingExtDict, lz4sd->prefixEnd - lz4sd->prefixSize, + lz4sd->externalDict, + lz4sd->extDictSize); + + if (result <= 0) + return result; + + lz4sd->prefixSize += result; + lz4sd->prefixEnd += result; + } else { + lz4sd->extDictSize = lz4sd->prefixSize; + lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize; + result = LZ4_decompress_generic(source, dest, + compressedSize, maxOutputSize, + endOnInputSize, full, 0, + usingExtDict, (BYTE *)dest, + lz4sd->externalDict, lz4sd->extDictSize); + if (result <= 0) + return result; + lz4sd->prefixSize = result; + lz4sd->prefixEnd = (BYTE *)dest + result; + } - /* get matchlength */ - length = (token & ML_MASK); - if (length == ML_MASK) { - while (ip < iend) { - int s = *ip++; - if (unlikely(length > (size_t)(length + s))) - goto _output_error; - length += s; - if (s == 255) - continue; - break; - } - } + return result; +} - /* copy repeated sequence */ - if (unlikely((op - ref) < STEPSIZE)) { -#if LZ4_ARCH64 - int dec64 = dec64table[op - ref]; -#else - const int dec64 = 0; -#endif - op[0] = ref[0]; - op[1] = ref[1]; - op[2] = ref[2]; - op[3] = ref[3]; - op += 4; - ref += 4; - ref -= dec32table[op - ref]; - PUT4(ref, op); - op += STEPSIZE - 4; - ref -= dec64; - } else { - LZ4_COPYSTEP(ref, op); - } - cpy = op + length - (STEPSIZE-4); - if (cpy > oend - COPYLENGTH) { - if (cpy > oend) - goto _output_error; /* write outside of buf */ -#if LZ4_ARCH64 - if ((ref + COPYLENGTH) > oend) -#else - if ((ref + COPYLENGTH) > oend || - (op + COPYLENGTH) > oend) -#endif - goto _output_error; - LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH)); - while (op < cpy) - *op++ = *ref++; - op = cpy; - /* - * Check EOF (should never happen, since last 5 bytes - * are supposed to be literals) - */ - if (op == oend) - goto _output_error; - continue; - } - LZ4_SECURECOPY(ref, op, cpy); - op = cpy; /* correction */ +int LZ4_decompress_fast_continue(LZ4_streamDecode_t *LZ4_streamDecode, + const char *source, char *dest, int originalSize) +{ + LZ4_streamDecode_t_internal *lz4sd = &LZ4_streamDecode->internal_donotuse; + int result; + + if (lz4sd->prefixEnd == (BYTE *)dest) { + result = LZ4_decompress_generic(source, dest, 0, originalSize, + endOnOutputSize, full, 0, + usingExtDict, + lz4sd->prefixEnd - lz4sd->prefixSize, + lz4sd->externalDict, lz4sd->extDictSize); + + if (result <= 0) + return result; + + lz4sd->prefixSize += originalSize; + lz4sd->prefixEnd += originalSize; + } else { + lz4sd->extDictSize = lz4sd->prefixSize; + lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize; + result = LZ4_decompress_generic(source, dest, 0, originalSize, + endOnOutputSize, full, 0, + usingExtDict, (BYTE *)dest, + lz4sd->externalDict, lz4sd->extDictSize); + if (result <= 0) + return result; + lz4sd->prefixSize = originalSize; + lz4sd->prefixEnd = (BYTE *)dest + originalSize; } - /* end of decoding */ - return (int) (((char *) op) - dest); - /* write overflow error detected */ -_output_error: - return -1; + return result; } -int lz4_decompress(const unsigned char *src, size_t *src_len, - unsigned char *dest, size_t actual_dest_len) +/* + * Advanced decoding functions : + * *_usingDict() : + * These decoding functions work the same as "_continue" ones, + * the dictionary must be explicitly provided within parameters + */ +static FORCE_INLINE int LZ4_decompress_usingDict_generic(const char *source, + char *dest, int compressedSize, int maxOutputSize, int safe, + const char *dictStart, int dictSize) { - int ret = -1; - int input_len = 0; - - input_len = lz4_uncompress(src, dest, actual_dest_len); - if (input_len < 0) - goto exit_0; - *src_len = input_len; + if (dictSize == 0) + return LZ4_decompress_generic(source, dest, + compressedSize, maxOutputSize, safe, full, 0, + noDict, (BYTE *)dest, NULL, 0); + if (dictStart + dictSize == dest) { + if (dictSize >= (int)(64 * KB - 1)) + return LZ4_decompress_generic(source, dest, + compressedSize, maxOutputSize, safe, full, 0, + withPrefix64k, (BYTE *)dest - 64 * KB, NULL, 0); + return LZ4_decompress_generic(source, dest, compressedSize, + maxOutputSize, safe, full, 0, noDict, + (BYTE *)dest - dictSize, NULL, 0); + } + return LZ4_decompress_generic(source, dest, compressedSize, + maxOutputSize, safe, full, 0, usingExtDict, + (BYTE *)dest, (const BYTE *)dictStart, dictSize); +} - return 0; -exit_0: - return ret; +int LZ4_decompress_safe_usingDict(const char *source, char *dest, + int compressedSize, int maxOutputSize, + const char *dictStart, int dictSize) +{ + return LZ4_decompress_usingDict_generic(source, dest, + compressedSize, maxOutputSize, 1, dictStart, dictSize); } -#ifndef STATIC -EXPORT_SYMBOL(lz4_decompress); -#endif -int lz4_decompress_unknownoutputsize(const unsigned char *src, size_t src_len, - unsigned char *dest, size_t *dest_len) +int LZ4_decompress_fast_usingDict(const char *source, char *dest, + int originalSize, const char *dictStart, int dictSize) { - int ret = -1; - int out_len = 0; - - out_len = lz4_uncompress_unknownoutputsize(src, dest, src_len, - *dest_len); - if (out_len < 0) - goto exit_0; - *dest_len = out_len; - - return 0; -exit_0: - return ret; + return LZ4_decompress_usingDict_generic(source, dest, 0, + originalSize, 0, dictStart, dictSize); } + +/*-****************************** + * For backwards compatibility + ********************************/ +int lz4_decompress_unknownoutputsize(const unsigned char *src, + size_t src_len, unsigned char *dest, size_t *dest_len) { + *dest_len = LZ4_decompress_safe(src, dest, + src_len, *dest_len); + + /* + * Prior lz4_decompress_unknownoutputsize will return + * 0 for success and a negative result for error + * new LZ4_decompress_safe returns + * - the length of data read on success + * - and also a negative result on error + * meaning when result > 0, we just return 0 here + */ + if (src_len > 0) + return 0; + else + return -1; +} + +int lz4_decompress(const unsigned char *src, size_t *src_len, + unsigned char *dest, size_t actual_dest_len) { + *src_len = LZ4_decompress_fast(src, dest, actual_dest_len); + + /* + * Prior lz4_decompress will return + * 0 for success and a negative result for error + * new LZ4_decompress_fast returns + * - the length of data read on success + * - and also a negative result on error + * meaning when result > 0, we just return 0 here + */ + if (*src_len > 0) + return 0; + else + return -1; +} + #ifndef STATIC +EXPORT_SYMBOL(LZ4_decompress_safe); +EXPORT_SYMBOL(LZ4_decompress_safe_partial); +EXPORT_SYMBOL(LZ4_decompress_fast); +EXPORT_SYMBOL(LZ4_setStreamDecode); +EXPORT_SYMBOL(LZ4_decompress_safe_continue); +EXPORT_SYMBOL(LZ4_decompress_fast_continue); +EXPORT_SYMBOL(LZ4_decompress_safe_usingDict); +EXPORT_SYMBOL(LZ4_decompress_fast_usingDict); EXPORT_SYMBOL(lz4_decompress_unknownoutputsize); +EXPORT_SYMBOL(lz4_decompress); MODULE_LICENSE("Dual BSD/GPL"); -MODULE_DESCRIPTION("LZ4 Decompressor"); +MODULE_DESCRIPTION("LZ4 decompressor"); #endif diff --git a/lib/lz4/lz4defs.h b/lib/lz4/lz4defs.h index c79d7ea8a38e..00a0b58a0871 100644 --- a/lib/lz4/lz4defs.h +++ b/lib/lz4/lz4defs.h @@ -1,157 +1,227 @@ +#ifndef __LZ4DEFS_H__ +#define __LZ4DEFS_H__ + /* - * lz4defs.h -- architecture specific defines - * - * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com> + * lz4defs.h -- common and architecture specific defines for the kernel usage + + * LZ4 - Fast LZ compression algorithm + * Copyright (C) 2011-2016, Yann Collet. + * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * You can contact the author at : + * - LZ4 homepage : http://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. + * Changed for kernel usage by: + * Sven Schmidt <4sschmid@informatik.uni-hamburg.de> */ -/* - * Detects 64 bits mode - */ +#include <asm/unaligned.h> +#include <linux/string.h> /* memset, memcpy */ + +#define FORCE_INLINE __always_inline + +/*-************************************ + * Basic Types + **************************************/ +#include <linux/types.h> + +typedef uint8_t BYTE; +typedef uint16_t U16; +typedef uint32_t U32; +typedef int32_t S32; +typedef uint64_t U64; +typedef uintptr_t uptrval; + +/*-************************************ + * Architecture specifics + **************************************/ #if defined(CONFIG_64BIT) #define LZ4_ARCH64 1 #else #define LZ4_ARCH64 0 #endif -/* - * Architecture-specific macros - */ -#define BYTE u8 -typedef struct _U16_S { u16 v; } U16_S; -typedef struct _U32_S { u32 v; } U32_S; -typedef struct _U64_S { u64 v; } U64_S; -#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) - -#define A16(x) (((U16_S *)(x))->v) -#define A32(x) (((U32_S *)(x))->v) -#define A64(x) (((U64_S *)(x))->v) - -#define PUT4(s, d) (A32(d) = A32(s)) -#define PUT8(s, d) (A64(d) = A64(s)) - -#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \ - (d = s - A16(p)) - -#define LZ4_WRITE_LITTLEENDIAN_16(p, v) \ - do { \ - A16(p) = v; \ - p += 2; \ - } while (0) -#else /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */ - -#define A64(x) get_unaligned((u64 *)&(((U16_S *)(x))->v)) -#define A32(x) get_unaligned((u32 *)&(((U16_S *)(x))->v)) -#define A16(x) get_unaligned((u16 *)&(((U16_S *)(x))->v)) - -#define PUT4(s, d) \ - put_unaligned(get_unaligned((const u32 *) s), (u32 *) d) -#define PUT8(s, d) \ - put_unaligned(get_unaligned((const u64 *) s), (u64 *) d) - -#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \ - (d = s - get_unaligned_le16(p)) - -#define LZ4_WRITE_LITTLEENDIAN_16(p, v) \ - do { \ - put_unaligned_le16(v, (u16 *)(p)); \ - p += 2; \ - } while (0) +#if defined(__LITTLE_ENDIAN) +#define LZ4_LITTLE_ENDIAN 1 +#else +#define LZ4_LITTLE_ENDIAN 0 #endif -#define COPYLENGTH 8 -#define ML_BITS 4 -#define ML_MASK ((1U << ML_BITS) - 1) +/*-************************************ + * Constants + **************************************/ +#define MINMATCH 4 + +#define WILDCOPYLENGTH 8 +#define LASTLITERALS 5 +#define MFLIMIT (WILDCOPYLENGTH + MINMATCH) + +/* Increase this value ==> compression run slower on incompressible data */ +#define LZ4_SKIPTRIGGER 6 + +#define HASH_UNIT sizeof(size_t) + +#define KB (1 << 10) +#define MB (1 << 20) +#define GB (1U << 30) + +#define MAXD_LOG 16 +#define MAX_DISTANCE ((1 << MAXD_LOG) - 1) +#define STEPSIZE sizeof(size_t) + +#define ML_BITS 4 +#define ML_MASK ((1U << ML_BITS) - 1) #define RUN_BITS (8 - ML_BITS) #define RUN_MASK ((1U << RUN_BITS) - 1) -#define MEMORY_USAGE 14 -#define MINMATCH 4 -#define SKIPSTRENGTH 6 -#define LASTLITERALS 5 -#define MFLIMIT (COPYLENGTH + MINMATCH) -#define MINLENGTH (MFLIMIT + 1) -#define MAXD_LOG 16 -#define MAXD (1 << MAXD_LOG) -#define MAXD_MASK (u32)(MAXD - 1) -#define MAX_DISTANCE (MAXD - 1) -#define HASH_LOG (MAXD_LOG - 1) -#define HASHTABLESIZE (1 << HASH_LOG) -#define MAX_NB_ATTEMPTS 256 -#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH) -#define LZ4_64KLIMIT ((1<<16) + (MFLIMIT - 1)) -#define HASHLOG64K ((MEMORY_USAGE - 2) + 1) -#define HASH64KTABLESIZE (1U << HASHLOG64K) -#define LZ4_HASH_VALUE(p) (((A32(p)) * 2654435761U) >> \ - ((MINMATCH * 8) - (MEMORY_USAGE-2))) -#define LZ4_HASH64K_VALUE(p) (((A32(p)) * 2654435761U) >> \ - ((MINMATCH * 8) - HASHLOG64K)) -#define HASH_VALUE(p) (((A32(p)) * 2654435761U) >> \ - ((MINMATCH * 8) - HASH_LOG)) - -#if LZ4_ARCH64/* 64-bit */ -#define STEPSIZE 8 - -#define LZ4_COPYSTEP(s, d) \ - do { \ - PUT8(s, d); \ - d += 8; \ - s += 8; \ - } while (0) - -#define LZ4_COPYPACKET(s, d) LZ4_COPYSTEP(s, d) - -#define LZ4_SECURECOPY(s, d, e) \ - do { \ - if (d < e) { \ - LZ4_WILDCOPY(s, d, e); \ - } \ - } while (0) -#define HTYPE u32 - -#ifdef __BIG_ENDIAN -#define LZ4_NBCOMMONBYTES(val) (__builtin_clzll(val) >> 3) + +/*-************************************ + * Reading and writing into memory + **************************************/ +static FORCE_INLINE U16 LZ4_read16(const void *ptr) +{ + return get_unaligned((const U16 *)ptr); +} + +static FORCE_INLINE U32 LZ4_read32(const void *ptr) +{ + return get_unaligned((const U32 *)ptr); +} + +static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr) +{ + return get_unaligned((const size_t *)ptr); +} + +static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value) +{ + put_unaligned(value, (U16 *)memPtr); +} + +static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value) +{ + put_unaligned(value, (U32 *)memPtr); +} + +static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr) +{ + return get_unaligned_le16(memPtr); +} + +static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value) +{ + return put_unaligned_le16(value, memPtr); +} + +static FORCE_INLINE void LZ4_copy8(void *dst, const void *src) +{ +#if LZ4_ARCH64 + U64 a = get_unaligned((const U64 *)src); + + put_unaligned(a, (U64 *)dst); +#else + U32 a = get_unaligned((const U32 *)src); + U32 b = get_unaligned((const U32 *)src + 1); + + put_unaligned(a, (U32 *)dst); + put_unaligned(b, (U32 *)dst + 1); +#endif +} + +/* + * customized variant of memcpy, + * which can overwrite up to 7 bytes beyond dstEnd + */ +static FORCE_INLINE void LZ4_wildCopy(void *dstPtr, + const void *srcPtr, void *dstEnd) +{ + BYTE *d = (BYTE *)dstPtr; + const BYTE *s = (const BYTE *)srcPtr; + BYTE *const e = (BYTE *)dstEnd; + + do { + LZ4_copy8(d, s); + d += 8; + s += 8; + } while (d < e); +} + +static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val) +{ +#if LZ4_LITTLE_ENDIAN + return __ffs(val) >> 3; #else -#define LZ4_NBCOMMONBYTES(val) (__builtin_ctzll(val) >> 3) + return (BITS_PER_LONG - 1 - __fls(val)) >> 3; +#endif +} + +static FORCE_INLINE unsigned int LZ4_count( + const BYTE *pIn, + const BYTE *pMatch, + const BYTE *pInLimit) +{ + const BYTE *const pStart = pIn; + + while (likely(pIn < pInLimit - (STEPSIZE - 1))) { + size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn); + + if (!diff) { + pIn += STEPSIZE; + pMatch += STEPSIZE; + continue; + } + + pIn += LZ4_NbCommonBytes(diff); + + return (unsigned int)(pIn - pStart); + } + +#if LZ4_ARCH64 + if ((pIn < (pInLimit - 3)) + && (LZ4_read32(pMatch) == LZ4_read32(pIn))) { + pIn += 4; + pMatch += 4; + } #endif -#else /* 32-bit */ -#define STEPSIZE 4 + if ((pIn < (pInLimit - 1)) + && (LZ4_read16(pMatch) == LZ4_read16(pIn))) { + pIn += 2; + pMatch += 2; + } -#define LZ4_COPYSTEP(s, d) \ - do { \ - PUT4(s, d); \ - d += 4; \ - s += 4; \ - } while (0) + if ((pIn < pInLimit) && (*pMatch == *pIn)) + pIn++; -#define LZ4_COPYPACKET(s, d) \ - do { \ - LZ4_COPYSTEP(s, d); \ - LZ4_COPYSTEP(s, d); \ - } while (0) + return (unsigned int)(pIn - pStart); +} -#define LZ4_SECURECOPY LZ4_WILDCOPY -#define HTYPE const u8* +typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive; +typedef enum { byPtr, byU32, byU16 } tableType_t; -#ifdef __BIG_ENDIAN -#define LZ4_NBCOMMONBYTES(val) (__builtin_clz(val) >> 3) -#else -#define LZ4_NBCOMMONBYTES(val) (__builtin_ctz(val) >> 3) -#endif +typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive; +typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive; -#endif +typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive; +typedef enum { full = 0, partial = 1 } earlyEnd_directive; -#define LZ4_WILDCOPY(s, d, e) \ - do { \ - LZ4_COPYPACKET(s, d); \ - } while (d < e) - -#define LZ4_BLINDCOPY(s, d, l) \ - do { \ - u8 *e = (d) + l; \ - LZ4_WILDCOPY(s, d, e); \ - d = e; \ - } while (0) +#endif diff --git a/lib/lz4/lz4hc_compress.c b/lib/lz4/lz4hc_compress.c index f344f76b6559..e1fbf1561e55 100644 --- a/lib/lz4/lz4hc_compress.c +++ b/lib/lz4/lz4hc_compress.c @@ -1,19 +1,17 @@ /* * LZ4 HC - High Compression Mode of LZ4 - * Copyright (C) 2011-2012, Yann Collet. - * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + * Copyright (C) 2011-2015, Yann Collet. * + * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php) * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: - * - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. - * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR @@ -25,323 +23,361 @@ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - * * You can contact the author at : - * - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html - * - LZ4 source repository : http://code.google.com/p/lz4/ + * - LZ4 homepage : http://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 * - * Changed for kernel use by: - * Chanho Min <chanho.min@lge.com> + * Changed for kernel usage by: + * Sven Schmidt <4sschmid@informatik.uni-hamburg.de> */ -#include <linux/module.h> -#include <linux/kernel.h> +/*-************************************ + * Dependencies + **************************************/ #include <linux/lz4.h> -#include <asm/unaligned.h> #include "lz4defs.h" +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/string.h> /* memset */ + +/* ************************************* + * Local Constants and types + ***************************************/ -struct lz4hc_data { - const u8 *base; - HTYPE hashtable[HASHTABLESIZE]; - u16 chaintable[MAXD]; - const u8 *nexttoupdate; -} __attribute__((__packed__)); +#define OPTIMAL_ML (int)((ML_MASK - 1) + MINMATCH) -static inline int lz4hc_init(struct lz4hc_data *hc4, const u8 *base) +#define HASH_FUNCTION(i) (((i) * 2654435761U) \ + >> ((MINMATCH*8) - LZ4HC_HASH_LOG)) +#define DELTANEXTU16(p) chainTable[(U16)(p)] /* faster */ + +static U32 LZ4HC_hashPtr(const void *ptr) +{ + return HASH_FUNCTION(LZ4_read32(ptr)); +} + +/************************************** + * HC Compression + **************************************/ +static void LZ4HC_init(LZ4HC_CCtx_internal *hc4, const BYTE *start) { - memset((void *)hc4->hashtable, 0, sizeof(hc4->hashtable)); - memset(hc4->chaintable, 0xFF, sizeof(hc4->chaintable)); - -#if LZ4_ARCH64 - hc4->nexttoupdate = base + 1; -#else - hc4->nexttoupdate = base; -#endif - hc4->base = base; - return 1; + memset((void *)hc4->hashTable, 0, sizeof(hc4->hashTable)); + memset(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); + hc4->nextToUpdate = 64 * KB; + hc4->base = start - 64 * KB; + hc4->end = start; + hc4->dictBase = start - 64 * KB; + hc4->dictLimit = 64 * KB; + hc4->lowLimit = 64 * KB; } /* Update chains up to ip (excluded) */ -static inline void lz4hc_insert(struct lz4hc_data *hc4, const u8 *ip) +static FORCE_INLINE void LZ4HC_Insert(LZ4HC_CCtx_internal *hc4, + const BYTE *ip) { - u16 *chaintable = hc4->chaintable; - HTYPE *hashtable = hc4->hashtable; -#if LZ4_ARCH64 + U16 * const chainTable = hc4->chainTable; + U32 * const hashTable = hc4->hashTable; const BYTE * const base = hc4->base; -#else - const int base = 0; -#endif + U32 const target = (U32)(ip - base); + U32 idx = hc4->nextToUpdate; + + while (idx < target) { + U32 const h = LZ4HC_hashPtr(base + idx); + size_t delta = idx - hashTable[h]; - while (hc4->nexttoupdate < ip) { - const u8 *p = hc4->nexttoupdate; - size_t delta = p - (hashtable[HASH_VALUE(p)] + base); if (delta > MAX_DISTANCE) delta = MAX_DISTANCE; - chaintable[(size_t)(p) & MAXD_MASK] = (u16)delta; - hashtable[HASH_VALUE(p)] = (p) - base; - hc4->nexttoupdate++; - } -} -static inline size_t lz4hc_commonlength(const u8 *p1, const u8 *p2, - const u8 *const matchlimit) -{ - const u8 *p1t = p1; - - while (p1t < matchlimit - (STEPSIZE - 1)) { -#if LZ4_ARCH64 - u64 diff = A64(p2) ^ A64(p1t); -#else - u32 diff = A32(p2) ^ A32(p1t); -#endif - if (!diff) { - p1t += STEPSIZE; - p2 += STEPSIZE; - continue; - } - p1t += LZ4_NBCOMMONBYTES(diff); - return p1t - p1; - } -#if LZ4_ARCH64 - if ((p1t < (matchlimit-3)) && (A32(p2) == A32(p1t))) { - p1t += 4; - p2 += 4; - } -#endif + DELTANEXTU16(idx) = (U16)delta; - if ((p1t < (matchlimit - 1)) && (A16(p2) == A16(p1t))) { - p1t += 2; - p2 += 2; + hashTable[h] = idx; + idx++; } - if ((p1t < matchlimit) && (*p2 == *p1t)) - p1t++; - return p1t - p1; + + hc4->nextToUpdate = target; } -static inline int lz4hc_insertandfindbestmatch(struct lz4hc_data *hc4, - const u8 *ip, const u8 *const matchlimit, const u8 **matchpos) +static FORCE_INLINE int LZ4HC_InsertAndFindBestMatch( + LZ4HC_CCtx_internal *hc4, /* Index table will be updated */ + const BYTE *ip, + const BYTE * const iLimit, + const BYTE **matchpos, + const int maxNbAttempts) { - u16 *const chaintable = hc4->chaintable; - HTYPE *const hashtable = hc4->hashtable; - const u8 *ref; -#if LZ4_ARCH64 + U16 * const chainTable = hc4->chainTable; + U32 * const HashTable = hc4->hashTable; const BYTE * const base = hc4->base; -#else - const int base = 0; -#endif - int nbattempts = MAX_NB_ATTEMPTS; - size_t repl = 0, ml = 0; - u16 delta; + const BYTE * const dictBase = hc4->dictBase; + const U32 dictLimit = hc4->dictLimit; + const U32 lowLimit = (hc4->lowLimit + 64 * KB > (U32)(ip - base)) + ? hc4->lowLimit + : (U32)(ip - base) - (64 * KB - 1); + U32 matchIndex; + int nbAttempts = maxNbAttempts; + size_t ml = 0; /* HC4 match finder */ - lz4hc_insert(hc4, ip); - ref = hashtable[HASH_VALUE(ip)] + base; - - /* potential repetition */ - if (ref >= ip-4) { - /* confirmed */ - if (A32(ref) == A32(ip)) { - delta = (u16)(ip-ref); - repl = ml = lz4hc_commonlength(ip + MINMATCH, - ref + MINMATCH, matchlimit) + MINMATCH; - *matchpos = ref; - } - ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK]; - } + LZ4HC_Insert(hc4, ip); + matchIndex = HashTable[LZ4HC_hashPtr(ip)]; + + while ((matchIndex >= lowLimit) + && (nbAttempts)) { + nbAttempts--; + if (matchIndex >= dictLimit) { + const BYTE * const match = base + matchIndex; + + if (*(match + ml) == *(ip + ml) + && (LZ4_read32(match) == LZ4_read32(ip))) { + size_t const mlt = LZ4_count(ip + MINMATCH, + match + MINMATCH, iLimit) + MINMATCH; - while ((ref >= ip - MAX_DISTANCE) && nbattempts) { - nbattempts--; - if (*(ref + ml) == *(ip + ml)) { - if (A32(ref) == A32(ip)) { - size_t mlt = - lz4hc_commonlength(ip + MINMATCH, - ref + MINMATCH, matchlimit) + MINMATCH; if (mlt > ml) { ml = mlt; - *matchpos = ref; + *matchpos = match; + } + } + } else { + const BYTE * const match = dictBase + matchIndex; + + if (LZ4_read32(match) == LZ4_read32(ip)) { + size_t mlt; + const BYTE *vLimit = ip + + (dictLimit - matchIndex); + + if (vLimit > iLimit) + vLimit = iLimit; + mlt = LZ4_count(ip + MINMATCH, + match + MINMATCH, vLimit) + MINMATCH; + if ((ip + mlt == vLimit) + && (vLimit < iLimit)) + mlt += LZ4_count(ip + mlt, + base + dictLimit, + iLimit); + if (mlt > ml) { + /* virtual matchpos */ + ml = mlt; + *matchpos = base + matchIndex; } } } - ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK]; - } - - /* Complete table */ - if (repl) { - const BYTE *ptr = ip; - const BYTE *end; - end = ip + repl - (MINMATCH-1); - /* Pre-Load */ - while (ptr < end - delta) { - chaintable[(size_t)(ptr) & MAXD_MASK] = delta; - ptr++; - } - do { - chaintable[(size_t)(ptr) & MAXD_MASK] = delta; - /* Head of chain */ - hashtable[HASH_VALUE(ptr)] = (ptr) - base; - ptr++; - } while (ptr < end); - hc4->nexttoupdate = end; + matchIndex -= DELTANEXTU16(matchIndex); } return (int)ml; } -static inline int lz4hc_insertandgetwidermatch(struct lz4hc_data *hc4, - const u8 *ip, const u8 *startlimit, const u8 *matchlimit, int longest, - const u8 **matchpos, const u8 **startpos) +static FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch( + LZ4HC_CCtx_internal *hc4, + const BYTE * const ip, + const BYTE * const iLowLimit, + const BYTE * const iHighLimit, + int longest, + const BYTE **matchpos, + const BYTE **startpos, + const int maxNbAttempts) { - u16 *const chaintable = hc4->chaintable; - HTYPE *const hashtable = hc4->hashtable; -#if LZ4_ARCH64 + U16 * const chainTable = hc4->chainTable; + U32 * const HashTable = hc4->hashTable; const BYTE * const base = hc4->base; -#else - const int base = 0; -#endif - const u8 *ref; - int nbattempts = MAX_NB_ATTEMPTS; - int delta = (int)(ip - startlimit); + const U32 dictLimit = hc4->dictLimit; + const BYTE * const lowPrefixPtr = base + dictLimit; + const U32 lowLimit = (hc4->lowLimit + 64 * KB > (U32)(ip - base)) + ? hc4->lowLimit + : (U32)(ip - base) - (64 * KB - 1); + const BYTE * const dictBase = hc4->dictBase; + U32 matchIndex; + int nbAttempts = maxNbAttempts; + int delta = (int)(ip - iLowLimit); /* First Match */ - lz4hc_insert(hc4, ip); - ref = hashtable[HASH_VALUE(ip)] + base; - - while ((ref >= ip - MAX_DISTANCE) && (ref >= hc4->base) - && (nbattempts)) { - nbattempts--; - if (*(startlimit + longest) == *(ref - delta + longest)) { - if (A32(ref) == A32(ip)) { - const u8 *reft = ref + MINMATCH; - const u8 *ipt = ip + MINMATCH; - const u8 *startt = ip; - - while (ipt < matchlimit-(STEPSIZE - 1)) { - #if LZ4_ARCH64 - u64 diff = A64(reft) ^ A64(ipt); - #else - u32 diff = A32(reft) ^ A32(ipt); - #endif - - if (!diff) { - ipt += STEPSIZE; - reft += STEPSIZE; - continue; + LZ4HC_Insert(hc4, ip); + matchIndex = HashTable[LZ4HC_hashPtr(ip)]; + + while ((matchIndex >= lowLimit) + && (nbAttempts)) { + nbAttempts--; + if (matchIndex >= dictLimit) { + const BYTE *matchPtr = base + matchIndex; + + if (*(iLowLimit + longest) + == *(matchPtr - delta + longest)) { + if (LZ4_read32(matchPtr) == LZ4_read32(ip)) { + int mlt = MINMATCH + LZ4_count( + ip + MINMATCH, + matchPtr + MINMATCH, + iHighLimit); + int back = 0; + + while ((ip + back > iLowLimit) + && (matchPtr + back > lowPrefixPtr) + && (ip[back - 1] == matchPtr[back - 1])) + back--; + + mlt -= back; + + if (mlt > longest) { + longest = (int)mlt; + *matchpos = matchPtr + back; + *startpos = ip + back; } - ipt += LZ4_NBCOMMONBYTES(diff); - goto _endcount; - } - #if LZ4_ARCH64 - if ((ipt < (matchlimit - 3)) - && (A32(reft) == A32(ipt))) { - ipt += 4; - reft += 4; } - ipt += 2; - #endif - if ((ipt < (matchlimit - 1)) - && (A16(reft) == A16(ipt))) { - reft += 2; - } - if ((ipt < matchlimit) && (*reft == *ipt)) - ipt++; -_endcount: - reft = ref; - - while ((startt > startlimit) - && (reft > hc4->base) - && (startt[-1] == reft[-1])) { - startt--; - reft--; - } - - if ((ipt - startt) > longest) { - longest = (int)(ipt - startt); - *matchpos = reft; - *startpos = startt; + } + } else { + const BYTE * const matchPtr = dictBase + matchIndex; + + if (LZ4_read32(matchPtr) == LZ4_read32(ip)) { + size_t mlt; + int back = 0; + const BYTE *vLimit = ip + (dictLimit - matchIndex); + + if (vLimit > iHighLimit) + vLimit = iHighLimit; + + mlt = LZ4_count(ip + MINMATCH, + matchPtr + MINMATCH, vLimit) + MINMATCH; + + if ((ip + mlt == vLimit) && (vLimit < iHighLimit)) + mlt += LZ4_count(ip + mlt, base + dictLimit, + iHighLimit); + while ((ip + back > iLowLimit) + && (matchIndex + back > lowLimit) + && (ip[back - 1] == matchPtr[back - 1])) + back--; + + mlt -= back; + + if ((int)mlt > longest) { + longest = (int)mlt; + *matchpos = base + matchIndex + back; + *startpos = ip + back; } } } - ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK]; + + matchIndex -= DELTANEXTU16(matchIndex); } + return longest; } -static inline int lz4_encodesequence(const u8 **ip, u8 **op, const u8 **anchor, - int ml, const u8 *ref) +static FORCE_INLINE int LZ4HC_encodeSequence( + const BYTE **ip, + BYTE **op, + const BYTE **anchor, + int matchLength, + const BYTE * const match, + limitedOutput_directive limitedOutputBuffer, + BYTE *oend) { - int length, len; - u8 *token; + int length; + BYTE *token; /* Encode Literal length */ length = (int)(*ip - *anchor); token = (*op)++; + + if ((limitedOutputBuffer) + && ((*op + (length>>8) + + length + (2 + 1 + LASTLITERALS)) > oend)) { + /* Check output limit */ + return 1; + } if (length >= (int)RUN_MASK) { - *token = (RUN_MASK << ML_BITS); + int len; + + *token = (RUN_MASK<<ML_BITS); len = length - RUN_MASK; for (; len > 254 ; len -= 255) *(*op)++ = 255; - *(*op)++ = (u8)len; + *(*op)++ = (BYTE)len; } else - *token = (length << ML_BITS); + *token = (BYTE)(length<<ML_BITS); /* Copy Literals */ - LZ4_BLINDCOPY(*anchor, *op, length); + LZ4_wildCopy(*op, *anchor, (*op) + length); + *op += length; /* Encode Offset */ - LZ4_WRITE_LITTLEENDIAN_16(*op, (u16)(*ip - ref)); + LZ4_writeLE16(*op, (U16)(*ip - match)); + *op += 2; /* Encode MatchLength */ - len = (int)(ml - MINMATCH); - if (len >= (int)ML_MASK) { + length = (int)(matchLength - MINMATCH); + + if ((limitedOutputBuffer) + && (*op + (length>>8) + + (1 + LASTLITERALS) > oend)) { + /* Check output limit */ + return 1; + } + + if (length >= (int)ML_MASK) { *token += ML_MASK; - len -= ML_MASK; - for (; len > 509 ; len -= 510) { + length -= ML_MASK; + + for (; length > 509 ; length -= 510) { *(*op)++ = 255; *(*op)++ = 255; } - if (len > 254) { - len -= 255; + + if (length > 254) { + length -= 255; *(*op)++ = 255; } - *(*op)++ = (u8)len; + + *(*op)++ = (BYTE)length; } else - *token += len; + *token += (BYTE)(length); /* Prepare next loop */ - *ip += ml; + *ip += matchLength; *anchor = *ip; return 0; } -static int lz4_compresshcctx(struct lz4hc_data *ctx, - const char *source, - char *dest, - int isize) +static int LZ4HC_compress_generic( + LZ4HC_CCtx_internal *const ctx, + const char * const source, + char * const dest, + int const inputSize, + int const maxOutputSize, + int compressionLevel, + limitedOutput_directive limit + ) { - const u8 *ip = (const u8 *)source; - const u8 *anchor = ip; - const u8 *const iend = ip + isize; - const u8 *const mflimit = iend - MFLIMIT; - const u8 *const matchlimit = (iend - LASTLITERALS); + const BYTE *ip = (const BYTE *) source; + const BYTE *anchor = ip; + const BYTE * const iend = ip + inputSize; + const BYTE * const mflimit = iend - MFLIMIT; + const BYTE * const matchlimit = (iend - LASTLITERALS); - u8 *op = (u8 *)dest; + BYTE *op = (BYTE *) dest; + BYTE * const oend = op + maxOutputSize; + unsigned int maxNbAttempts; int ml, ml2, ml3, ml0; - const u8 *ref = NULL; - const u8 *start2 = NULL; - const u8 *ref2 = NULL; - const u8 *start3 = NULL; - const u8 *ref3 = NULL; - const u8 *start0; - const u8 *ref0; - int lastrun; + const BYTE *ref = NULL; + const BYTE *start2 = NULL; + const BYTE *ref2 = NULL; + const BYTE *start3 = NULL; + const BYTE *ref3 = NULL; + const BYTE *start0; + const BYTE *ref0; + + /* init */ + if (compressionLevel > LZ4HC_MAX_CLEVEL) + compressionLevel = LZ4HC_MAX_CLEVEL; + if (compressionLevel < 1) + compressionLevel = LZ4HC_DEFAULT_CLEVEL; + maxNbAttempts = 1 << (compressionLevel - 1); + ctx->end += inputSize; ip++; /* Main Loop */ while (ip < mflimit) { - ml = lz4hc_insertandfindbestmatch(ctx, ip, matchlimit, (&ref)); + ml = LZ4HC_InsertAndFindBestMatch(ctx, ip, + matchlimit, (&ref), maxNbAttempts); if (!ml) { ip++; continue; @@ -351,51 +387,59 @@ static int lz4_compresshcctx(struct lz4hc_data *ctx, start0 = ip; ref0 = ref; ml0 = ml; -_search2: - if (ip+ml < mflimit) - ml2 = lz4hc_insertandgetwidermatch(ctx, ip + ml - 2, - ip + 1, matchlimit, ml, &ref2, &start2); + +_Search2: + if (ip + ml < mflimit) + ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, + ip + ml - 2, ip + 0, + matchlimit, ml, &ref2, + &start2, maxNbAttempts); else ml2 = ml; - /* No better match */ + if (ml2 == ml) { - lz4_encodesequence(&ip, &op, &anchor, ml, ref); + /* No better match */ + if (LZ4HC_encodeSequence(&ip, &op, + &anchor, ml, ref, limit, oend)) + return 0; continue; } if (start0 < ip) { - /* empirical */ if (start2 < ip + ml0) { + /* empirical */ ip = start0; ref = ref0; ml = ml0; } } - /* - * Here, start0==ip - * First Match too small : removed - */ + + /* Here, start0 == ip */ if ((start2 - ip) < 3) { + /* First Match too small : removed */ ml = ml2; ip = start2; ref = ref2; - goto _search2; + goto _Search2; } -_search3: +_Search3: /* - * Currently we have : - * ml2 > ml1, and - * ip1+3 <= ip2 (usually < ip1+ml1) - */ + * Currently we have : + * ml2 > ml1, and + * ip1 + 3 <= ip2 (usually < ip1 + ml1) + */ if ((start2 - ip) < OPTIMAL_ML) { int correction; int new_ml = ml; + if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML; if (ip + new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH; + correction = new_ml - (int)(start2 - ip); + if (correction > 0) { start2 += correction; ref2 += correction; @@ -403,39 +447,44 @@ _search3: } } /* - * Now, we have start2 = ip+new_ml, - * with new_ml=min(ml, OPTIMAL_ML=18) + * Now, we have start2 = ip + new_ml, + * with new_ml = min(ml, OPTIMAL_ML = 18) */ + if (start2 + ml2 < mflimit) - ml3 = lz4hc_insertandgetwidermatch(ctx, - start2 + ml2 - 3, start2, matchlimit, - ml2, &ref3, &start3); + ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, + start2 + ml2 - 3, start2, + matchlimit, ml2, &ref3, &start3, + maxNbAttempts); else ml3 = ml2; - /* No better match : 2 sequences to encode */ if (ml3 == ml2) { + /* No better match : 2 sequences to encode */ /* ip & ref are known; Now for ml */ - if (start2 < ip+ml) + if (start2 < ip + ml) ml = (int)(start2 - ip); - /* Now, encode 2 sequences */ - lz4_encodesequence(&ip, &op, &anchor, ml, ref); + if (LZ4HC_encodeSequence(&ip, &op, &anchor, + ml, ref, limit, oend)) + return 0; ip = start2; - lz4_encodesequence(&ip, &op, &anchor, ml2, ref2); + if (LZ4HC_encodeSequence(&ip, &op, &anchor, + ml2, ref2, limit, oend)) + return 0; continue; } - /* Not enough space for match 2 : remove it */ if (start3 < ip + ml + 3) { - /* - * can write Seq1 immediately ==> Seq2 is removed, - * so Seq3 becomes Seq1 - */ + /* Not enough space for match 2 : remove it */ if (start3 >= (ip + ml)) { + /* can write Seq1 immediately + * ==> Seq2 is removed, + * so Seq3 becomes Seq1 + */ if (start2 < ip + ml) { - int correction = - (int)(ip + ml - start2); + int correction = (int)(ip + ml - start2); + start2 += correction; ref2 += correction; ml2 -= correction; @@ -446,35 +495,38 @@ _search3: } } - lz4_encodesequence(&ip, &op, &anchor, ml, ref); - ip = start3; + if (LZ4HC_encodeSequence(&ip, &op, &anchor, + ml, ref, limit, oend)) + return 0; + ip = start3; ref = ref3; - ml = ml3; + ml = ml3; start0 = start2; ref0 = ref2; ml0 = ml2; - goto _search2; + goto _Search2; } start2 = start3; ref2 = ref3; ml2 = ml3; - goto _search3; + goto _Search3; } /* - * OK, now we have 3 ascending matches; let's write at least - * the first one ip & ref are known; Now for ml - */ + * OK, now we have 3 ascending matches; + * let's write at least the first one + * ip & ref are known; Now for ml + */ if (start2 < ip + ml) { if ((start2 - ip) < (int)ML_MASK) { int correction; + if (ml > OPTIMAL_ML) ml = OPTIMAL_ML; if (ip + ml > start2 + ml2 - MINMATCH) - ml = (int)(start2 - ip) + ml2 - - MINMATCH; + ml = (int)(start2 - ip) + ml2 - MINMATCH; correction = ml - (int)(start2 - ip); if (correction > 0) { start2 += correction; @@ -484,7 +536,9 @@ _search3: } else ml = (int)(start2 - ip); } - lz4_encodesequence(&ip, &op, &anchor, ml, ref); + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, + ref, limit, oend)) + return 0; ip = start2; ref = ref2; @@ -494,46 +548,245 @@ _search3: ref2 = ref3; ml2 = ml3; - goto _search3; + goto _Search3; } /* Encode Last Literals */ - lastrun = (int)(iend - anchor); - if (lastrun >= (int)RUN_MASK) { - *op++ = (RUN_MASK << ML_BITS); - lastrun -= RUN_MASK; - for (; lastrun > 254 ; lastrun -= 255) - *op++ = 255; - *op++ = (u8) lastrun; - } else - *op++ = (lastrun << ML_BITS); - memcpy(op, anchor, iend - anchor); - op += iend - anchor; + { + int lastRun = (int)(iend - anchor); + + if ((limit) + && (((char *)op - dest) + lastRun + 1 + + ((lastRun + 255 - RUN_MASK)/255) + > (U32)maxOutputSize)) { + /* Check output limit */ + return 0; + } + if (lastRun >= (int)RUN_MASK) { + *op++ = (RUN_MASK<<ML_BITS); + lastRun -= RUN_MASK; + for (; lastRun > 254 ; lastRun -= 255) + *op++ = 255; + *op++ = (BYTE) lastRun; + } else + *op++ = (BYTE)(lastRun<<ML_BITS); + memcpy(op, anchor, iend - anchor); + op += iend - anchor; + } + /* End */ return (int) (((char *)op) - dest); } -int lz4hc_compress(const unsigned char *src, size_t src_len, - unsigned char *dst, size_t *dst_len, void *wrkmem) +static int LZ4_compress_HC_extStateHC( + void *state, + const char *src, + char *dst, + int srcSize, + int maxDstSize, + int compressionLevel) { - int ret = -1; - int out_len = 0; + LZ4HC_CCtx_internal *ctx = &((LZ4_streamHC_t *)state)->internal_donotuse; - struct lz4hc_data *hc4 = (struct lz4hc_data *)wrkmem; - lz4hc_init(hc4, (const u8 *)src); - out_len = lz4_compresshcctx((struct lz4hc_data *)hc4, (const u8 *)src, - (char *)dst, (int)src_len); + if (((size_t)(state)&(sizeof(void *) - 1)) != 0) { + /* Error : state is not aligned + * for pointers (32 or 64 bits) + */ + return 0; + } - if (out_len < 0) - goto exit; + LZ4HC_init(ctx, (const BYTE *)src); - *dst_len = out_len; - return 0; + if (maxDstSize < LZ4_compressBound(srcSize)) + return LZ4HC_compress_generic(ctx, src, dst, + srcSize, maxDstSize, compressionLevel, limitedOutput); + else + return LZ4HC_compress_generic(ctx, src, dst, + srcSize, maxDstSize, compressionLevel, noLimit); +} + +int LZ4_compress_HC(const char *src, char *dst, int srcSize, + int maxDstSize, int compressionLevel, void *wrkmem) +{ + return LZ4_compress_HC_extStateHC(wrkmem, src, dst, + srcSize, maxDstSize, compressionLevel); +} +EXPORT_SYMBOL(LZ4_compress_HC); + +/************************************** + * Streaming Functions + **************************************/ +void LZ4_resetStreamHC(LZ4_streamHC_t *LZ4_streamHCPtr, int compressionLevel) +{ + LZ4_streamHCPtr->internal_donotuse.base = NULL; + LZ4_streamHCPtr->internal_donotuse.compressionLevel = (unsigned int)compressionLevel; +} + +int LZ4_loadDictHC(LZ4_streamHC_t *LZ4_streamHCPtr, + const char *dictionary, + int dictSize) +{ + LZ4HC_CCtx_internal *ctxPtr = &LZ4_streamHCPtr->internal_donotuse; + + if (dictSize > 64 * KB) { + dictionary += dictSize - 64 * KB; + dictSize = 64 * KB; + } + LZ4HC_init(ctxPtr, (const BYTE *)dictionary); + if (dictSize >= 4) + LZ4HC_Insert(ctxPtr, (const BYTE *)dictionary + (dictSize - 3)); + ctxPtr->end = (const BYTE *)dictionary + dictSize; + return dictSize; +} +EXPORT_SYMBOL(LZ4_loadDictHC); + +/* compression */ + +static void LZ4HC_setExternalDict( + LZ4HC_CCtx_internal *ctxPtr, + const BYTE *newBlock) +{ + if (ctxPtr->end >= ctxPtr->base + 4) { + /* Referencing remaining dictionary content */ + LZ4HC_Insert(ctxPtr, ctxPtr->end - 3); + } + + /* + * Only one memory segment for extDict, + * so any previous extDict is lost at this stage + */ + ctxPtr->lowLimit = ctxPtr->dictLimit; + ctxPtr->dictLimit = (U32)(ctxPtr->end - ctxPtr->base); + ctxPtr->dictBase = ctxPtr->base; + ctxPtr->base = newBlock - ctxPtr->dictLimit; + ctxPtr->end = newBlock; + /* match referencing will resume from there */ + ctxPtr->nextToUpdate = ctxPtr->dictLimit; +} +EXPORT_SYMBOL(LZ4HC_setExternalDict); + +static int LZ4_compressHC_continue_generic( + LZ4_streamHC_t *LZ4_streamHCPtr, + const char *source, + char *dest, + int inputSize, + int maxOutputSize, + limitedOutput_directive limit) +{ + LZ4HC_CCtx_internal *ctxPtr = &LZ4_streamHCPtr->internal_donotuse; + + /* auto - init if forgotten */ + if (ctxPtr->base == NULL) + LZ4HC_init(ctxPtr, (const BYTE *) source); + + /* Check overflow */ + if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 * GB) { + size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->base) + - ctxPtr->dictLimit; + if (dictSize > 64 * KB) + dictSize = 64 * KB; + LZ4_loadDictHC(LZ4_streamHCPtr, + (const char *)(ctxPtr->end) - dictSize, (int)dictSize); + } + + /* Check if blocks follow each other */ + if ((const BYTE *)source != ctxPtr->end) + LZ4HC_setExternalDict(ctxPtr, (const BYTE *)source); + + /* Check overlapping input/dictionary space */ + { + const BYTE *sourceEnd = (const BYTE *) source + inputSize; + const BYTE * const dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit; + const BYTE * const dictEnd = ctxPtr->dictBase + ctxPtr->dictLimit; + + if ((sourceEnd > dictBegin) + && ((const BYTE *)source < dictEnd)) { + if (sourceEnd > dictEnd) + sourceEnd = dictEnd; + ctxPtr->lowLimit = (U32)(sourceEnd - ctxPtr->dictBase); + + if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4) + ctxPtr->lowLimit = ctxPtr->dictLimit; + } + } + + return LZ4HC_compress_generic(ctxPtr, source, dest, + inputSize, maxOutputSize, ctxPtr->compressionLevel, limit); +} + +int LZ4_compress_HC_continue( + LZ4_streamHC_t *LZ4_streamHCPtr, + const char *source, + char *dest, + int inputSize, + int maxOutputSize) +{ + if (maxOutputSize < LZ4_compressBound(inputSize)) + return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, + source, dest, inputSize, maxOutputSize, limitedOutput); + else + return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, + source, dest, inputSize, maxOutputSize, noLimit); +} +EXPORT_SYMBOL(LZ4_compress_HC_continue); + +/* dictionary saving */ + +int LZ4_saveDictHC( + LZ4_streamHC_t *LZ4_streamHCPtr, + char *safeBuffer, + int dictSize) +{ + LZ4HC_CCtx_internal *const streamPtr = &LZ4_streamHCPtr->internal_donotuse; + int const prefixSize = (int)(streamPtr->end + - (streamPtr->base + streamPtr->dictLimit)); + + if (dictSize > 64 * KB) + dictSize = 64 * KB; + if (dictSize < 4) + dictSize = 0; + if (dictSize > prefixSize) + dictSize = prefixSize; + + memmove(safeBuffer, streamPtr->end - dictSize, dictSize); -exit: - return ret; + { + U32 const endIndex = (U32)(streamPtr->end - streamPtr->base); + + streamPtr->end = (const BYTE *)safeBuffer + dictSize; + streamPtr->base = streamPtr->end - endIndex; + streamPtr->dictLimit = endIndex - dictSize; + streamPtr->lowLimit = endIndex - dictSize; + + if (streamPtr->nextToUpdate < streamPtr->dictLimit) + streamPtr->nextToUpdate = streamPtr->dictLimit; + } + return dictSize; +} +EXPORT_SYMBOL(LZ4_saveDictHC); + +/*-****************************** + * For backwards compatibility + ********************************/ +int lz4hc_compress(const unsigned char *src, size_t src_len, + unsigned char *dst, size_t *dst_len, void *wrkmem) +{ + *dst_len = LZ4_compress_HC(src, dst, src_len, + *dst_len, LZ4HC_DEFAULT_CLEVEL, wrkmem); + + /* + * Prior lz4hc_compress will return -1 in case of error + * and 0 on success + * while new LZ4_compress_HC + * returns 0 in case of error + * and the output length on success + */ + if (!*dst_len) + return -1; + else + return 0; } EXPORT_SYMBOL(lz4hc_compress); MODULE_LICENSE("Dual BSD/GPL"); -MODULE_DESCRIPTION("LZ4HC compressor"); +MODULE_DESCRIPTION("LZ4 HC compressor"); |