diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/lz4.c | 163 |
1 files changed, 114 insertions, 49 deletions
@@ -92,6 +92,7 @@ * Dependency **************************************/ #define LZ4_STATIC_LINKING_ONLY +#define LZ4_DISABLE_DEPRECATE_WARNINGS /* due to LZ4_decompress_safe_withPrefix64k */ #include "lz4.h" /* see also "memory routines" below */ @@ -1554,6 +1555,8 @@ _output_error: } +/*===== Instantiate the API decoding functions. =====*/ + LZ4_FORCE_O2_GCC_PPC64LE int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize) { @@ -1575,9 +1578,76 @@ 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); + (BYTE*)dest - 64 KB, NULL, 0); +} + +/*===== Instantiate a few more decoding cases, used more than once. =====*/ + +LZ4_FORCE_O2_GCC_PPC64LE /* Exported, an obsolete API function. */ +int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, + endOnInputSize, full, 0, withPrefix64k, + (BYTE*)dest - 64 KB, NULL, 0); +} + +/* Another obsolete API function, paired with the previous one. */ +int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize) +{ + /* LZ4_decompress_fast doesn't validate match offsets, + * and thus serves well with any prefixed dictionary. */ + return LZ4_decompress_fast(source, dest, originalSize); +} + +LZ4_FORCE_O2_GCC_PPC64LE +static int LZ4_decompress_safe_withSmallPrefix(const char* source, char* dest, int compressedSize, int maxOutputSize, + size_t prefixSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, + endOnInputSize, full, 0, noDict, + (BYTE*)dest-prefixSize, NULL, 0); } +LZ4_FORCE_O2_GCC_PPC64LE /* Exported under another name, for tests/fullbench.c */ +#define LZ4_decompress_safe_extDict LZ4_decompress_safe_forceExtDict +int LZ4_decompress_safe_extDict(const char* source, char* dest, int compressedSize, int maxOutputSize, + const void* dictStart, size_t dictSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, + endOnInputSize, full, 0, usingExtDict, + (BYTE*)dest, (const BYTE*)dictStart, dictSize); +} + +LZ4_FORCE_O2_GCC_PPC64LE +static int LZ4_decompress_fast_extDict(const char* source, char* dest, int originalSize, + const void* dictStart, size_t dictSize) +{ + return LZ4_decompress_generic(source, dest, 0, originalSize, + endOnOutputSize, full, 0, usingExtDict, + (BYTE*)dest, (const BYTE*)dictStart, dictSize); +} + +/* The "double dictionary" mode, for use with e.g. ring buffers: the first part + * of the dictionary is passed as prefix, and the second via dictStart + dictSize. + * These routines are used only once, in LZ4_decompress_*_continue(). + */ +LZ4_FORCE_INLINE +int LZ4_decompress_safe_doubleDict(const char* source, char* dest, int compressedSize, int maxOutputSize, + size_t prefixSize, const void* dictStart, size_t dictSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, + endOnInputSize, full, 0, usingExtDict, + (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize); +} + +LZ4_FORCE_INLINE +int LZ4_decompress_fast_doubleDict(const char* source, char* dest, int originalSize, + size_t prefixSize, const void* dictStart, size_t dictSize) +{ + return LZ4_decompress_generic(source, dest, 0, originalSize, + endOnOutputSize, full, 0, usingExtDict, + (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize); +} /*===== streaming decompression functions =====*/ @@ -1624,19 +1694,32 @@ int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch 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 (lz4sd->prefixSize == 0) { + /* The first call, no dictionary yet. */ + assert(lz4sd->extDictSize == 0); + result = LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize); + if (result <= 0) return result; + lz4sd->prefixSize = result; + lz4sd->prefixEnd = (BYTE*)dest + result; + } else if (lz4sd->prefixEnd == (BYTE*)dest) { + /* They're rolling the current segment. */ + if (lz4sd->prefixSize >= 64 KB - 1) + result = LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize); + else if (lz4sd->extDictSize == 0) + result = LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize, + lz4sd->prefixSize); + else + result = LZ4_decompress_safe_doubleDict(source, dest, compressedSize, maxOutputSize, + lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize); if (result <= 0) return result; lz4sd->prefixSize += result; lz4sd->prefixEnd += result; } else { + /* The buffer wraps around, or they're switching to another buffer. */ 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); + result = LZ4_decompress_safe_extDict(source, dest, compressedSize, maxOutputSize, + lz4sd->externalDict, lz4sd->extDictSize); if (result <= 0) return result; lz4sd->prefixSize = result; lz4sd->prefixEnd = (BYTE*)dest + result; @@ -1651,19 +1734,26 @@ int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch 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 (lz4sd->prefixSize == 0) { + assert(lz4sd->extDictSize == 0); + result = LZ4_decompress_fast(source, dest, originalSize); + if (result <= 0) return result; + lz4sd->prefixSize = originalSize; + lz4sd->prefixEnd = (BYTE*)dest + originalSize; + } else if (lz4sd->prefixEnd == (BYTE*)dest) { + if (lz4sd->prefixSize >= 64 KB - 1 || lz4sd->extDictSize == 0) + result = LZ4_decompress_fast(source, dest, originalSize); + else + result = LZ4_decompress_fast_doubleDict(source, dest, originalSize, + 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); + result = LZ4_decompress_fast_extDict(source, dest, originalSize, + lz4sd->externalDict, lz4sd->extDictSize); if (result <= 0) return result; lz4sd->prefixSize = originalSize; lz4sd->prefixEnd = (BYTE*)dest + originalSize; @@ -1680,36 +1770,23 @@ Advanced decoding functions : the dictionary must be explicitly provided within parameters */ -LZ4_FORCE_O2_GCC_PPC64LE -LZ4_FORCE_INLINE int LZ4_decompress_usingDict_generic(const char* source, char* dest, int compressedSize, int maxOutputSize, int safe, const char* dictStart, int dictSize) +int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize) { if (dictSize==0) - return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, noDict, (BYTE*)dest, NULL, 0); + return LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize); 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); + if (dictSize >= 64 KB - 1) + return LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize); + return LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize, dictSize); } - return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, usingExtDict, (BYTE*)dest, (const BYTE*)dictStart, dictSize); -} - -LZ4_FORCE_O2_GCC_PPC64LE -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); + return LZ4_decompress_safe_extDict(source, dest, compressedSize, maxOutputSize, dictStart, dictSize); } -LZ4_FORCE_O2_GCC_PPC64LE int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize) { - return LZ4_decompress_usingDict_generic(source, dest, 0, originalSize, 0, dictStart, dictSize); -} - -/* debug function */ -LZ4_FORCE_O2_GCC_PPC64LE -int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize) -{ - return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, (BYTE*)dest, (const BYTE*)dictStart, dictSize); + if (dictSize==0 || dictStart+dictSize == dest) + return LZ4_decompress_fast(source, dest, originalSize); + return LZ4_decompress_fast_extDict(source, dest, originalSize, dictStart, dictSize); } @@ -1780,16 +1857,4 @@ char* LZ4_slideInputBuffer (void* state) return (char *)(uptrval)((LZ4_stream_t*)state)->internal_donotuse.dictionary; } -/* Obsolete streaming decompression functions */ - -int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize) -{ - return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, withPrefix64k, (BYTE*)dest - 64 KB, NULL, 64 KB); -} - -int LZ4_decompress_fast_withPrefix64k(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); -} - #endif /* LZ4_COMMONDEFS_ONLY */ |