/* LZ4 - Fast LZ compression algorithm Copyright (C) 2011-2012, 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://fastcompression.blogspot.com/p/lz4.html - LZ4 source repository : http://code.google.com/p/lz4/ */ //************************************** // Tuning parameters //************************************** // COMPRESSIONLEVEL : // Increasing this value improves compression ratio // Lowering this value reduces memory usage // Reduced memory usage typically improves speed, due to cache effect (ex : L1 32KB for Intel, L1 64KB for AMD) // Memory usage formula : N->2^(N+2) Bytes (examples : 12 -> 16KB ; 17 -> 512KB) #define COMPRESSIONLEVEL 12 // NOTCOMPRESSIBLE_CONFIRMATION : // Decreasing this value will make the algorithm skip faster data segments considered "incompressible" // This may decrease compression ratio dramatically, but will be faster on incompressible data // Increasing this value will make the algorithm search more before declaring a segment "incompressible" // This could improve compression a bit, but will be slower on incompressible data // The default value (6) is recommended #define NOTCOMPRESSIBLE_CONFIRMATION 6 // LZ4_COMPRESSMIN : // Compression function will *fail* if it is not successful at compressing input by at least LZ4_COMPRESSMIN bytes // Since the compression function stops working prematurely, it results in a speed gain // The output however is unusable. Compression function result will be zero. // Default : 0 = disabled #define LZ4_COMPRESSMIN 0 // BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE : // This will provide a boost to performance for big endian cpu, but the resulting compressed stream will be incompatible with little-endian CPU. // You can set this option to 1 in situations where data will stay within closed environment // This option is useless on Little_Endian CPU (such as x86) //#define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1 //************************************** // CPU Feature Detection //************************************** // 32 or 64 bits ? #if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) || defined(__amd64) || defined(__ppc64__) || defined(_WIN64) || defined(__LP64__) || defined(_LP64) ) // Detects 64 bits mode # define LZ4_ARCH64 1 #else # define LZ4_ARCH64 0 #endif // Little Endian or Big Endian ? // Note : overwrite the below #define if you know your architecture endianess #if (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || defined(_BIG_ENDIAN) || defined(_ARCH_PPC) || defined(__PPC__) || defined(__PPC) || defined(PPC) || defined(__powerpc__) || defined(__powerpc) || defined(powerpc) || ((defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))) ) # define LZ4_BIG_ENDIAN 1 #else // Little Endian assumed. PDP Endian and other very rare endian format are unsupported. #endif // Unaligned memory access is automatically enabled for "common" CPU, such as x86. // For others CPU, the compiler will be more cautious, and insert extra code to ensure aligned access is respected // If you know your target CPU supports unaligned memory access, you may want to force this option manually to improve performance #if defined(__ARM_FEATURE_UNALIGNED) # define LZ4_FORCE_UNALIGNED_ACCESS 1 #endif // Define this parameter if your target system or compiler does not support hardware bit count #if defined(_MSC_VER) && defined(_WIN32_WCE) // Visual Studio for Windows CE does not support Hardware bit count # define LZ4_FORCE_SW_BITCOUNT #endif //************************************** // Compiler Options //************************************** #if __STDC_VERSION__ >= 199901L // C99 /* "restrict" is a known keyword */ #else # define restrict // Disable restrict #endif #define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__) #ifdef _MSC_VER // Visual Studio # define inline __forceinline // Visual is not C99, but supports some kind of inline # if LZ4_ARCH64 // 64-bit # pragma intrinsic(_BitScanForward64) // For Visual 2005 # pragma intrinsic(_BitScanReverse64) // For Visual 2005 # else # pragma intrinsic(_BitScanForward) // For Visual 2005 # pragma intrinsic(_BitScanReverse) // For Visual 2005 # endif #endif #ifdef _MSC_VER # define lz4_bswap16(x) _byteswap_ushort(x) #else # define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8))) #endif #if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__) # define expect(expr,value) (__builtin_expect ((expr),(value)) ) #else # define expect(expr,value) (expr) #endif #define likely(expr) expect((expr) != 0, 1) #define unlikely(expr) expect((expr) != 0, 0) //************************************** // Includes //************************************** #include // for malloc #include // for memset #include "lz4.h" //************************************** // Basic Types //************************************** #if defined(_MSC_VER) // Visual Studio does not support 'stdint' natively # define BYTE unsigned __int8 # define U16 unsigned __int16 # define U32 unsigned __int32 # define S32 __int32 # define U64 unsigned __int64 #else # include # define BYTE uint8_t # define U16 uint16_t # define U32 uint32_t # define S32 int32_t # define U64 uint64_t #endif #ifndef LZ4_FORCE_UNALIGNED_ACCESS # pragma pack(push, 1) #endif typedef struct _U16_S { U16 v; } U16_S; typedef struct _U32_S { U32 v; } U32_S; typedef struct _U64_S { U64 v; } U64_S; #ifndef LZ4_FORCE_UNALIGNED_ACCESS # pragma pack(pop) #endif #define A64(x) (((U64_S *)(x))->v) #define A32(x) (((U32_S *)(x))->v) #define A16(x) (((U16_S *)(x))->v) //************************************** // Constants //************************************** #define MINMATCH 4 #define HASH_LOG COMPRESSIONLEVEL #define HASHTABLESIZE (1 << HASH_LOG) #define HASH_MASK (HASHTABLESIZE - 1) #define SKIPSTRENGTH (NOTCOMPRESSIBLE_CONFIRMATION>2?NOTCOMPRESSIBLE_CONFIRMATION:2) #define STACKLIMIT 13 #define HEAPMODE (HASH_LOG>STACKLIMIT) // Defines if memory is allocated into the stack (local variable), or into the heap (malloc()). #define COPYLENGTH 8 #define LASTLITERALS 5 #define MFLIMIT (COPYLENGTH+MINMATCH) #define MINLENGTH (MFLIMIT+1) #define MAXD_LOG 16 #define MAX_DISTANCE ((1 << MAXD_LOG) - 1) #define ML_BITS 4 #define ML_MASK ((1U<> ((MINMATCH*8)-HASH_LOG)) #define LZ4_HASH_VALUE(p) LZ4_HASH_FUNCTION(A32(p)) #define LZ4_WILDCOPY(s,d,e) do { LZ4_COPYPACKET(s,d) } while (d>3); #elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) return (__builtin_clzll(val) >> 3); #else int r; if (!(val>>32)) { r=4; } else { r=0; val>>=32; } if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; } r += (!val); return r; #endif #else #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) unsigned long r = 0; _BitScanForward64( &r, val ); return (int)(r>>3); #elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) return (__builtin_ctzll(val) >> 3); #else static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 }; return DeBruijnBytePos[((U64)((val & -val) * 0x0218A392CDABBD3F)) >> 58]; #endif #endif } #else inline static int LZ4_NbCommonBytes (register U32 val) { #if defined(LZ4_BIG_ENDIAN) #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) unsigned long r = 0; _BitScanReverse( &r, val ); return (int)(r>>3); #elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) return (__builtin_clz(val) >> 3); #else int r; if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; } r += (!val); return r; #endif #else #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) unsigned long r = 0; _BitScanForward( &r, val ); return (int)(r>>3); #elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) return (__builtin_ctz(val) >> 3); #else static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 }; return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27]; #endif #endif } #endif //**************************** // Public functions //**************************** int LZ4_compressBound(int isize) { return (isize + (isize/255) + 16); } //****************************** // Compression functions //****************************** int LZ4_compressCtx(void** ctx, const char* source, char* dest, int isize) { #if HEAPMODE struct refTables *srt = (struct refTables *) (*ctx); HTYPE* HashTable; #else HTYPE HashTable[HASHTABLESIZE] = {0}; #endif const BYTE* ip = (BYTE*) source; INITBASE(base); const BYTE* anchor = ip; const BYTE* const iend = ip + isize; const BYTE* const mflimit = iend - MFLIMIT; #define matchlimit (iend - LASTLITERALS) BYTE* op = (BYTE*) dest; int len, length; const int skipStrength = SKIPSTRENGTH; U32 forwardH; // Init if (isizehashTable); memset((void*)HashTable, 0, sizeof(srt->hashTable)); #else (void) ctx; #endif // First Byte HashTable[LZ4_HASH_VALUE(ip)] = ip - base; ip++; forwardH = LZ4_HASH_VALUE(ip); // Main Loop for ( ; ; ) { int findMatchAttempts = (1U << skipStrength) + 3; const BYTE* forwardIp = ip; const BYTE* ref; 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))); // Catch up while ((ip>anchor) && (ref>(BYTE*)source) && unlikely(ip[-1]==ref[-1])) { ip--; ref--; } // Encode Literal length length = ip - anchor; token = op++; if (length>=(int)RUN_MASK) { *token=(RUN_MASK< 254 ; len-=255) *op++ = 255; *op++ = (BYTE)len; } else *token = (length<=(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++ = (BYTE)len; } else *token += len; // Test end of chunk if (ip > mflimit) { anchor = ip; break; } // Fill table HashTable[LZ4_HASH_VALUE(ip-2)] = ip - 2 - 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))) { token = op++; *token=0; goto _next_match; } // Prepare next loop anchor = ip++; forwardH = LZ4_HASH_VALUE(ip); } _last_literals: // Encode Last Literals { int lastRun = iend - anchor; if ((LZ4_COMPRESSMIN>0) && (((op - (BYTE*)dest) + lastRun + 1 + ((lastRun-15)/255)) > isize - LZ4_COMPRESSMIN)) return 0; if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK< 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; } else *op++ = (lastRun<> ((MINMATCH*8)-HASHLOG64K)) #define LZ4_HASH64K_VALUE(p) LZ4_HASH64K_FUNCTION(A32(p)) int LZ4_compress64kCtx(void** ctx, const char* source, char* dest, int isize) { #if HEAPMODE struct refTables *srt = (struct refTables *) (*ctx); U16* HashTable; #else U16 HashTable[HASH64KTABLESIZE] = {0}; #endif const BYTE* ip = (BYTE*) source; const BYTE* anchor = ip; const BYTE* const base = ip; const BYTE* const iend = ip + isize; const BYTE* const mflimit = iend - MFLIMIT; #define matchlimit (iend - LASTLITERALS) BYTE* op = (BYTE*) dest; int len, length; const int skipStrength = SKIPSTRENGTH; U32 forwardH; // Init if (isizehashTable); memset((void*)HashTable, 0, sizeof(srt->hashTable)); #else (void) ctx; #endif // First Byte ip++; forwardH = LZ4_HASH64K_VALUE(ip); // Main Loop for ( ; ; ) { int findMatchAttempts = (1U << skipStrength) + 3; const BYTE* forwardIp = ip; const BYTE* ref; 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] = ip - base; } while (A32(ref) != A32(ip)); // Catch up while ((ip>anchor) && (ref>(BYTE*)source) && (ip[-1]==ref[-1])) { ip--; ref--; } // Encode Literal length length = ip - anchor; token = op++; if (length>=(int)RUN_MASK) { *token=(RUN_MASK< 254 ; len-=255) *op++ = 255; *op++ = (BYTE)len; } else *token = (length<=(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++ = (BYTE)len; } else *token += len; // Test end of chunk if (ip > mflimit) { anchor = ip; break; } // Fill table HashTable[LZ4_HASH64K_VALUE(ip-2)] = ip - 2 - base; // Test next position ref = base + HashTable[LZ4_HASH64K_VALUE(ip)]; HashTable[LZ4_HASH64K_VALUE(ip)] = ip - base; if (A32(ref) == A32(ip)) { token = op++; *token=0; goto _next_match; } // Prepare next loop anchor = ip++; forwardH = LZ4_HASH64K_VALUE(ip); } _last_literals: // Encode Last Literals { int lastRun = iend - anchor; if ((LZ4_COMPRESSMIN>0) && (((op - (BYTE*)dest) + lastRun + 1 + ((lastRun-15)/255)) > isize - LZ4_COMPRESSMIN)) return 0; if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK< 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; } else *op++ = (lastRun<>ML_BITS)) == RUN_MASK) { for (;(len=*ip++)==255;length+=255){} length += len; } // copy literals cpy = op+length; if unlikely(cpy>oend-COPYLENGTH) { if (cpy > oend) goto _output_error; // Error : request to write beyond destination buffer memcpy(op, ip, length); ip += length; break; // Necessarily EOF } LZ4_WILDCOPY(ip, op, cpy); ip -= (op-cpy); op = cpy; // get offset LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2; if (ref < (BYTE* const)dest) goto _output_error; // Error : offset create reference outside destination buffer // get matchlength if ((length=(token&ML_MASK)) == ML_MASK) { for (;*ip==255;length+=255) {ip++;} length += *ip++; } // copy repeated sequence if unlikely(op-refoend-COPYLENGTH) { if (cpy > oend) goto _output_error; // Error : request to write beyond destination buffer LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH)); while(op>ML_BITS)) == RUN_MASK) { int s=255; while ((ipoend-COPYLENGTH) || (ip+length>iend-COPYLENGTH)) { if (cpy > oend) goto _output_error; // Error : request to write beyond destination buffer if (ip+length > iend) goto _output_error; // Error : request to read beyond source buffer memcpy(op, ip, length); op += length; ip += length; if (ipoend-COPYLENGTH) { if (cpy > oend) goto _output_error; // Error : request to write outside of destination buffer LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH)); while(op