Signed-off-by: Andrew Mahone <andrew.mah...@gmail.com> --- fs/btrfs/lz4.c | 843 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/lz4.h | 128 +++++++++ fs/btrfs/lz4hc.c | 685 ++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/lz4hc.h | 58 ++++ 4 files changed, 1714 insertions(+) create mode 100644 fs/btrfs/lz4.c create mode 100644 fs/btrfs/lz4.h create mode 100644 fs/btrfs/lz4hc.c create mode 100644 fs/btrfs/lz4hc.h
diff --git a/fs/btrfs/lz4.c b/fs/btrfs/lz4.c new file mode 100644 index 0000000..87d18fe --- /dev/null +++ b/fs/btrfs/lz4.c @@ -0,0 +1,843 @@ +/* + 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. +*/ +/* + * With authors permission dual licensed as BSD/GPL for linux kernel + * + * Origin: http://lz4.googlecode.com/svn/trunk + * Revision: 62 + */ + +//************************************** +// 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 ? +#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 + +// Uncomment this parameter if your target system or compiler does not support hardware bit count +//#define LZ4_FORCE_SW_BITCOUNT + + + +//************************************** +// Compiler Options +//************************************** +#if defined(__STDC_VERSION__) && __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 +#include <intrin.h> // _BitScanForward +#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 + + +//************************************** +// Includes +//************************************** +#ifdef __KERNEL__ +#include <linux/string.h> +#include <linux/bug.h> +#define malloc(size) ({ BUG(); (void*)0; }) +#define free(ptr) ({ BUG(); (void*)0; }) +#else +#include <stdlib.h> // for malloc +#include <string.h> // for memset +#include "lz4.h" +#endif + + +//************************************** +// 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 +#ifdef __KERNEL__ +#include <asm/byteorder.h> +#include <linux/types.h> +#define BYTE u8 +#define U16 u16 +#define U32 u32 +#define S32 s32 +#define U64 u64 + +#else +#include <stdint.h> +#define BYTE uint8_t +#define U16 uint16_t +#define U32 uint32_t +#define S32 int32_t +#define U64 uint64_t +#endif // __KERNEL__ +#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<<ML_BITS)-1) +#define RUN_BITS (8-ML_BITS) +#define RUN_MASK ((1U<<RUN_BITS)-1) + +/* + * Disable on-stack context allocation for linux kernel + */ +#undef STACKLIMIT +#define STACKLIMIT 0 + + +//************************************** +// Architecture-specific macros +//************************************** +#if LZ4_ARCH64 // 64-bit +#define STEPSIZE 8 +#define UARCH U64 +#define AARCH A64 +#define LZ4_COPYSTEP(s,d) A64(d) = A64(s); d+=8; s+=8; +#define LZ4_COPYPACKET(s,d) LZ4_COPYSTEP(s,d) +#define LZ4_SECURECOPY(s,d,e) if (d<e) LZ4_WILDCOPY(s,d,e) +#define HTYPE U32 +#define INITBASE(base) const BYTE* const base = ip +#else // 32-bit +#define STEPSIZE 4 +#define UARCH U32 +#define AARCH A32 +#define LZ4_COPYSTEP(s,d) A32(d) = A32(s); d+=4; s+=4; +#define LZ4_COPYPACKET(s,d) LZ4_COPYSTEP(s,d); LZ4_COPYSTEP(s,d); +#define LZ4_SECURECOPY LZ4_WILDCOPY +#define HTYPE const BYTE* +#define INITBASE(base) const int base = 0 +#endif + +#if (defined(LZ4_BIG_ENDIAN) && !defined(BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE)) +#define LZ4_READ_LITTLEENDIAN_16(d,s,p) { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; } +#define LZ4_WRITE_LITTLEENDIAN_16(p,i) { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p+=2; } +#else // Little Endian +#define LZ4_READ_LITTLEENDIAN_16(d,s,p) { d = (s) - A16(p); } +#define LZ4_WRITE_LITTLEENDIAN_16(p,v) { A16(p) = v; p+=2; } +#endif + + +//************************************** +// Local structures +//************************************** +struct refTables +{ + HTYPE hashTable[HASHTABLESIZE]; +}; + + +//************************************** +// Macros +//************************************** +#define LZ4_HASH_FUNCTION(i) (((i) * 2654435761U) >> ((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<e); +#define LZ4_BLINDCOPY(s,d,l) { BYTE* e=(d)+l; LZ4_WILDCOPY(s,d,e); d=e; } + + +//**************************** +// Private functions +//**************************** +#if LZ4_ARCH64 + +inline static int LZ4_NbCommonBytes (register U64 val) +{ +#if defined(LZ4_BIG_ENDIAN) + #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) + unsigned long r = 0; + _BitScanReverse64( &r, val ); + return (int)(r>>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 (isize<MINLENGTH) goto _last_literals; +#if HEAPMODE + if (*ctx == NULL) + { + srt = (struct refTables *) malloc ( sizeof(struct refTables) ); + *ctx = (void*) srt; + } + HashTable = (HTYPE*)(srt->hashTable); + 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<<ML_BITS); len = length-RUN_MASK; for(; len > 254 ; len-=255) *op++ = 255; *op++ = (BYTE)len; } + else *token = (length<<ML_BITS); + + // Copy Literals + LZ4_BLINDCOPY(anchor, op, length); + +_next_match: + // Encode Offset + LZ4_WRITE_LITTLEENDIAN_16(op,ip-ref); + + // Start Counting + ip+=MINMATCH; ref+=MINMATCH; // MinMatch verified + anchor = ip; + while (likely(ip<matchlimit-(STEPSIZE-1))) + { + UARCH diff = AARCH(ref) ^ AARCH(ip); + 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; } + if ((ip<(matchlimit-1)) && (A16(ref) == A16(ip))) { ip+=2; ref+=2; } + if ((ip<matchlimit) && (*ref == *ip)) ip++; +_endCount: + + // Encode MatchLength + len = (ip - anchor); + 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++ = (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<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; } + else *op++ = (lastRun<<ML_BITS); + memcpy(op, anchor, iend - anchor); + op += iend-anchor; + } + + // End + return (int) (((char*)op)-dest); +} + + + +// Note : this function is valid only if isize < LZ4_64KLIMIT +#define LZ4_64KLIMIT ((1<<16) + (MFLIMIT-1)) +#define HASHLOG64K (HASH_LOG+1) +#define HASH64KTABLESIZE (1U<<HASHLOG64K) +#define LZ4_HASH64K_FUNCTION(i) (((i) * 2654435761U) >> ((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 (isize<MINLENGTH) goto _last_literals; +#if HEAPMODE + if (*ctx == NULL) + { + srt = (struct refTables *) malloc ( sizeof(struct refTables) ); + *ctx = (void*) srt; + } + HashTable = (U16*)(srt->hashTable); + 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<<ML_BITS); len = length-RUN_MASK; for(; len > 254 ; len-=255) *op++ = 255; *op++ = (BYTE)len; } + else *token = (length<<ML_BITS); + + // Copy Literals + LZ4_BLINDCOPY(anchor, op, length); + +_next_match: + // Encode Offset + LZ4_WRITE_LITTLEENDIAN_16(op,ip-ref); + + // Start Counting + ip+=MINMATCH; ref+=MINMATCH; // MinMatch verified + anchor = ip; + while (ip<matchlimit-(STEPSIZE-1)) + { + UARCH diff = AARCH(ref) ^ AARCH(ip); + 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; } + if ((ip<(matchlimit-1)) && (A16(ref) == A16(ip))) { ip+=2; ref+=2; } + if ((ip<matchlimit) && (*ref == *ip)) ip++; +_endCount: + + // Encode MatchLength + len = (ip - anchor); + 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++ = (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<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; } + else *op++ = (lastRun<<ML_BITS); + memcpy(op, anchor, iend - anchor); + op += iend-anchor; + } + + // End + return (int) (((char*)op)-dest); +} + + + +int LZ4_compress(const char* source, + char* dest, + int isize) +{ +#if HEAPMODE + void* ctx = malloc(sizeof(struct refTables)); + int result; + if (isize < LZ4_64KLIMIT) + result = LZ4_compress64kCtx(&ctx, source, dest, isize); + else result = LZ4_compressCtx(&ctx, source, dest, isize); + free(ctx); + return result; +#else + if (isize < (int)LZ4_64KLIMIT) return LZ4_compress64kCtx(NULL, source, dest, isize); + return LZ4_compressCtx(NULL, source, dest, isize); +#endif +} + + + + +//**************************** +// Decompression functions +//**************************** + +// Note : The decoding functions LZ4_uncompress() and LZ4_uncompress_unknownOutputSize() +// are safe against "buffer overflow" attack type. +// They will never write nor read outside of the provided output buffers. +// LZ4_uncompress_unknownOutputSize() also insures that it will never read outside of the input buffer. +// A corrupted input will produce an error result, a negative int, indicating the position of the error within input stream. + +int LZ4_uncompress(const char* source, + char* dest, + int osize) +{ + // Local Variables + const BYTE* restrict ip = (const BYTE*) source; + const BYTE* restrict ref; + + BYTE* restrict op = (BYTE*) dest; + BYTE* const oend = op + osize; + BYTE* cpy; + + BYTE token; + + int len, length; + size_t dec[] ={0, 3, 2, 3, 0, 0, 0, 0}; + + + // Main Loop + while (1) + { + // get runlength + token = *ip++; + if ((length=(token>>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; + 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; + + // get matchlength + if ((length=(token&ML_MASK)) == ML_MASK) { for (;*ip==255;length+=255) {ip++;} length += *ip++; } + + // copy repeated sequence + if (unlikely(op-ref<STEPSIZE)) + { +#if LZ4_ARCH64 + size_t dec2table[]={0, 0, 0, -1, 0, 1, 2, 3}; + size_t dec2 = dec2table[op-ref]; +#else + const int dec2 = 0; +#endif + *op++ = *ref++; + *op++ = *ref++; + *op++ = *ref++; + *op++ = *ref++; + ref -= dec[op-ref]; + A32(op)=A32(ref); op += STEPSIZE-4; + ref -= dec2; + } else { LZ4_COPYSTEP(ref,op); } + cpy = op + length - (STEPSIZE-4); + if (cpy>oend-COPYLENGTH) + { + if (cpy > oend) goto _output_error; + LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH)); + while(op<cpy) *op++=*ref++; + op=cpy; + if (op == oend) break; // Check EOF (should never happen, since last 5 bytes are supposed to be literals) + continue; + } + LZ4_SECURECOPY(ref, op, cpy); + op=cpy; // correction + } + + // end of decoding + return (int) (((char*)ip)-source); + + // write overflow error detected +_output_error: + return (int) (-(((char*)ip)-source)); +} + + +int LZ4_uncompress_unknownOutputSize( + const char* source, + char* dest, + int isize, + int maxOutputSize) +{ + // Local Variables + const BYTE* restrict ip = (const BYTE*) source; + const BYTE* const iend = ip + isize; + const BYTE* restrict ref; + + BYTE* restrict op = (BYTE*) dest; + BYTE* const oend = op + maxOutputSize; + BYTE* cpy; + + size_t dec[] ={0, 3, 2, 3, 0, 0, 0, 0}; + + + // Main Loop + while (ip<iend) + { + BYTE token; + int length; + + // get runlength + token = *ip++; + if ((length=(token>>ML_BITS)) == RUN_MASK) { int s=255; while ((ip<iend) && (s==255)) { s=*ip++; length += s; } } + + // copy literals + cpy = op+length; + if ((cpy>oend-COPYLENGTH) || (ip+length>iend-COPYLENGTH)) + { + if (cpy > oend) goto _output_error; + if (ip+length > iend) goto _output_error; + memcpy(op, ip, length); + op += length; + ip += length; + if (ip<iend) goto _output_error; + break; // Necessarily EOF, due to parsing restrictions + } + 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; + + // get matchlength + if ((length=(token&ML_MASK)) == ML_MASK) { while (ip<iend) { int s = *ip++; length +=s; if (s==255) continue; break; } } + + // copy repeated sequence + if (unlikely(op-ref<STEPSIZE)) + { +#if LZ4_ARCH64 + size_t dec2table[]={0, 0, 0, -1, 0, 1, 2, 3}; + size_t dec2 = dec2table[op-ref]; +#else + const int dec2 = 0; +#endif + *op++ = *ref++; + *op++ = *ref++; + *op++ = *ref++; + *op++ = *ref++; + ref -= dec[op-ref]; + A32(op)=A32(ref); op += STEPSIZE-4; + ref -= dec2; + } else { LZ4_COPYSTEP(ref,op); } + cpy = op + length - (STEPSIZE-4); + if (cpy>oend-COPYLENGTH) + { + if (cpy > oend) goto _output_error; + LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH)); + while(op<cpy) *op++=*ref++; + op=cpy; + if (op == oend) break; // Check EOF (should never happen, since last 5 bytes are supposed to be literals) + continue; + } + LZ4_SECURECOPY(ref, op, cpy); + op=cpy; // correction + } + + // end of decoding + return (int) (((char*)op)-dest); + + // write overflow error detected +_output_error: + return (int) (-(((char*)ip)-source)); +} + +int LZ4_context_size(void) +{ + return sizeof(struct refTables); +} +int LZ4_context64k_size(void) +{ + return sizeof(struct refTables); +} + diff --git a/fs/btrfs/lz4.h b/fs/btrfs/lz4.h new file mode 100644 index 0000000..dcd8f44 --- /dev/null +++ b/fs/btrfs/lz4.h @@ -0,0 +1,128 @@ +/* + LZ4 - Fast LZ compression algorithm + Header File + Copyright (C) 2011, Yann Collet. + BSD License + + 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. +*/ + +/* + * With authors permission dual licensed as BSD/GPL for linux kernel + * + * Origin: http://lz4.googlecode.com/svn/trunk + * Revision: 62 + */ +#pragma once + +#if defined (__cplusplus) +extern "C" { +#endif + + +//**************************** +// Simple Functions +//**************************** + +int LZ4_compress (const char* source, char* dest, int isize); +int LZ4_uncompress (const char* source, char* dest, int osize); + +/* +LZ4_compress() : + isize : is the input size. Max supported value is ~1.9GB + return : the number of bytes written in buffer dest + or 0 if the compression fails (if LZ4_COMPRESSMIN is set) + note : destination buffer must be already allocated. + destination buffer must be sized to handle worst cases situations (input data not compressible) + worst case size evaluation is provided by function LZ4_compressBound() + +LZ4_uncompress() : + osize : is the output size, therefore the original size + return : the number of bytes read in the source buffer + If the source stream is malformed, the function will stop decoding and return a negative result, indicating the byte position of the faulty instruction + This function never writes beyond dest + osize, and is therefore protected against malicious data packets + note : destination buffer must be already allocated +*/ + + +//**************************** +// Advanced Functions +//**************************** + +int LZ4_compressBound(int isize); + +/* +LZ4_compressBound() : + Provides the maximum size that LZ4 may output in a "worst case" scenario (input data not compressible) + primarily useful for memory allocation of output buffer. + + isize : is the input size. Max supported value is ~1.9GB + return : maximum output size in a "worst case" scenario + note : this function is limited by "int" range (2^31-1) +*/ + + +int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); + +/* +LZ4_uncompress_unknownOutputSize() : + isize : is the input size, therefore the compressed size + maxOutputSize : is the size of the destination buffer (which must be already allocated) + return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize) + If the source stream is malformed, the function will stop decoding and return a negative result, indicating the byte position of the faulty instruction + This function never writes beyond dest + maxOutputSize, and is therefore protected against malicious data packets + note : This version is slightly slower than LZ4_uncompress() +*/ + + +int LZ4_compressCtx(void** ctx, const char* source, char* dest, int isize); + +/* +LZ4_compressCtx() : + This function explicitly handles the CTX memory structure. + It avoids allocating/deallocating memory between each call, improving performance when malloc is heavily invoked. + This function is only useful when memory is allocated into the heap (HASH_LOG value beyond STACK_LIMIT) + Performance difference will be noticeable only when repetitively calling the compression function over many small segments. + Note : by default, memory is allocated into the stack, therefore "malloc" is not invoked. +LZ4_compress64kCtx() : + Same as LZ4_compressCtx(), but specific to small inputs (<64KB). + isize *Must* be <64KB, otherwise the output will be corrupted. + + On first call : provide a *ctx=NULL; It will be automatically allocated. + On next calls : reuse the same ctx pointer. + Use different pointers for different threads when doing multi-threading. + +*/ + +int LZ4_compress64kCtx(void** ctx, + const char* source, + char* dest, + int isize); + +int LZ4_context_size(void); +int LZ4_context64k_size(void); + +#if defined (__cplusplus) +} +#endif diff --git a/fs/btrfs/lz4hc.c b/fs/btrfs/lz4hc.c new file mode 100644 index 0000000..f69c77a --- /dev/null +++ b/fs/btrfs/lz4hc.c @@ -0,0 +1,685 @@ +/* + LZ4 HC - High Compression Mode of LZ4 + Copyright (C) 2011-2012, Yann Collet. + L-GPL v3 License + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License along + with this program; if not, see <http://www.gnu.org/licenses/>, + or write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + + You can contact the author at : + - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html + - LZ4-HC source repository : http://code.google.com/p/lz4hc/ +*/ + + + +//************************************** +// 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 ? +#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 + + +//************************************** +// Compiler Options +//************************************** +#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L // C99 + /* "restrict" is a known keyword */ +#else +#define restrict // Disable restrict +#endif + +#ifdef _MSC_VER +#define inline __forceinline // Visual is not C99, but supports some kind of inline +#endif + +#ifdef _MSC_VER // Visual Studio +#define bswap16(x) _byteswap_ushort(x) +#else +#define bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8))) +#endif + + +//************************************** +// Includes +//************************************** +#ifdef __KERNEL__ +#include <linux/string.h> +#include <linux/bug.h> +#define calloc(x,size) ({ BUG(); (void*)0; }) +#define malloc(size) ({ BUG(); (void*)0; }) +#define free(ptr) ({ BUG(); (void*)0; }) +#else +#include <stdlib.h> // calloc, free +#include <string.h> // memset, memcpy +#include "lz4hc.h" +#endif + +#define ALLOCATOR(s) calloc(1,s) +#define FREEMEM free +#define MEM_INIT memset + + +//************************************** +// 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 +#ifdef __KERNEL__ +#include <asm/byteorder.h> +#include <linux/types.h> +#define BYTE u8 +#define U16 u16 +#define U32 u32 +#define S32 s32 +#define U64 u64 + +#else +#include <stdint.h> +#define BYTE uint8_t +#define U16 uint16_t +#define U32 uint32_t +#define S32 int32_t +#define U64 uint64_t +#endif // __KERNEL__ +#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 DICTIONARY_LOGSIZE 16 +#define MAXD (1<<DICTIONARY_LOGSIZE) +#define MAXD_MASK ((U32)(MAXD - 1)) +#define MAX_DISTANCE (MAXD - 1) + +#define HASH_LOG (DICTIONARY_LOGSIZE-1) +#define HASHTABLESIZE (1 << HASH_LOG) +#define HASH_MASK (HASHTABLESIZE - 1) + +#define MAX_NB_ATTEMPTS 256 + +#define ML_BITS 4 +#define ML_MASK (size_t)((1U<<ML_BITS)-1) +#define RUN_BITS (8-ML_BITS) +#define RUN_MASK ((1U<<RUN_BITS)-1) + +#define COPYLENGTH 8 +#define LASTLITERALS 5 +#define MFLIMIT (COPYLENGTH+MINMATCH) +#define MINLENGTH (MFLIMIT+1) +#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH) + + +//************************************** +// Architecture-specific macros +//************************************** +#if LZ4_ARCH64 // 64-bit +#define STEPSIZE 8 +#define LZ4_COPYSTEP(s,d) A64(d) = A64(s); d+=8; s+=8; +#define LZ4_COPYPACKET(s,d) LZ4_COPYSTEP(s,d) +#define UARCH U64 +#define AARCH A64 +#define HTYPE U32 +#define INITBASE(b,s) const BYTE* const b = s +#else // 32-bit +#define STEPSIZE 4 +#define LZ4_COPYSTEP(s,d) A32(d) = A32(s); d+=4; s+=4; +#define LZ4_COPYPACKET(s,d) LZ4_COPYSTEP(s,d); LZ4_COPYSTEP(s,d); +#define UARCH U32 +#define AARCH A32 +#define HTYPE const BYTE* +#define INITBASE(b,s) const int b = 0 +#endif + +#if defined(LZ4_BIG_ENDIAN) +#define LZ4_READ_LITTLEENDIAN_16(d,s,p) { U16 v = A16(p); v = bswap16(v); d = (s) - v; } +#define LZ4_WRITE_LITTLEENDIAN_16(p,i) { U16 v = (U16)(i); v = bswap16(v); A16(p) = v; p+=2; } +#else // Little Endian +#define LZ4_READ_LITTLEENDIAN_16(d,s,p) { d = (s) - A16(p); } +#define LZ4_WRITE_LITTLEENDIAN_16(p,v) { A16(p) = v; p+=2; } +#endif + + +//************************************************************ +// Local Types +//************************************************************ +typedef struct +{ + const BYTE* base; + HTYPE hashTable[HASHTABLESIZE]; + U16 chainTable[MAXD]; + const BYTE* nextToUpdate; +} LZ4HC_Data_Structure; + + +//************************************** +// Macros +//************************************** +#define LZ4_WILDCOPY(s,d,e) do { LZ4_COPYPACKET(s,d) } while (d<e); +#define LZ4_BLINDCOPY(s,d,l) { BYTE* e=d+l; LZ4_WILDCOPY(s,d,e); d=e; } +#define HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-HASH_LOG)) +#define HASH_VALUE(p) HASH_FUNCTION(*(U32*)(p)) +#define HASH_POINTER(p) (HashTable[HASH_VALUE(p)] + base) +#define DELTANEXT(p) chainTable[(size_t)(p) & MAXD_MASK] +#define GETNEXT(p) ((p) - (size_t)DELTANEXT(p)) +#define ADD_HASH(p) { size_t delta = (p) - HASH_POINTER(p); if (delta>MAX_DISTANCE) delta = MAX_DISTANCE; DELTANEXT(p) = (U16)delta; HashTable[HASH_VALUE(p)] = (p) - base; } + + +//************************************** +// Private functions +//************************************** +#if LZ4_ARCH64 + +inline static int LZ4_NbCommonBytes (register U64 val) +{ +#if defined(LZ4_BIG_ENDIAN) + #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) + unsigned long r = 0; + _BitScanReverse64( &r, val ); + return (int)(r>>3); + #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 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__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 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__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 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__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 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 + + +inline static int LZ4HC_Init (LZ4HC_Data_Structure* hc4, const BYTE* base) +{ + MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable)); + MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); + hc4->nextToUpdate = base + LZ4_ARCH64; + hc4->base = base; + return 1; +} + + +inline static void* LZ4HC_Create (const BYTE* base) +{ + void* hc4 = ALLOCATOR(sizeof(LZ4HC_Data_Structure)); + + LZ4HC_Init (hc4, base); + return hc4; +} + + +inline static int LZ4HC_Free (void** LZ4HC_Data) +{ + FREEMEM(*LZ4HC_Data); + *LZ4HC_Data = NULL; + return (1); +} + + +inline static void LZ4HC_Insert (LZ4HC_Data_Structure* hc4, const BYTE* ip) +{ + U16* chainTable = hc4->chainTable; + HTYPE* HashTable = hc4->hashTable; + INITBASE(base,hc4->base); + + while(hc4->nextToUpdate < ip) + { + ADD_HASH(hc4->nextToUpdate); + hc4->nextToUpdate++; + } +} + + +inline static int LZ4HC_InsertAndFindBestMatch (LZ4HC_Data_Structure* hc4, const BYTE* ip, const BYTE* const matchlimit, const BYTE** matchpos) +{ + U16* const chainTable = hc4->chainTable; + HTYPE* const HashTable = hc4->hashTable; + const BYTE* ref; + INITBASE(base,hc4->base); + int nbAttempts=MAX_NB_ATTEMPTS; + int ml=0; + + // HC4 match finder + LZ4HC_Insert(hc4, ip); + ref = HASH_POINTER(ip); + while ((ref > (ip-MAX_DISTANCE)) && (nbAttempts)) + { + nbAttempts--; + if (*(ref+ml) == *(ip+ml)) + if (*(U32*)ref == *(U32*)ip) + { + const BYTE* reft = ref+MINMATCH; + const BYTE* ipt = ip+MINMATCH; + + while (ipt<matchlimit-(STEPSIZE-1)) + { + UARCH diff = AARCH(reft) ^ AARCH(ipt); + if (!diff) { ipt+=STEPSIZE; reft+=STEPSIZE; continue; } + ipt += LZ4_NbCommonBytes(diff); + goto _endCount; + } + if (LZ4_ARCH64) if ((ipt<(matchlimit-3)) && (A32(reft) == A32(ipt))) { ipt+=4; reft+=4; } + if ((ipt<(matchlimit-1)) && (A16(reft) == A16(ipt))) { ipt+=2; reft+=2; } + if ((ipt<matchlimit) && (*reft == *ipt)) ipt++; +_endCount: + + if (ipt-ip > ml) { ml = ipt-ip; *matchpos = ref; } + } + ref = GETNEXT(ref); + } + + return ml; +} + + +inline static int LZ4HC_InsertAndGetWiderMatch (LZ4HC_Data_Structure* hc4, const BYTE* ip, const BYTE* startLimit, const BYTE* matchlimit, int longest, const BYTE** matchpos, const BYTE** startpos) +{ + U16* const chainTable = hc4->chainTable; + HTYPE* const HashTable = hc4->hashTable; + INITBASE(base,hc4->base); + const BYTE* ref; + int nbAttempts = MAX_NB_ATTEMPTS; + int delta = ip-startLimit; + + // First Match + LZ4HC_Insert(hc4, ip); + ref = HASH_POINTER(ip); + + while ((ref > ip-MAX_DISTANCE) && (ref >= hc4->base) && (nbAttempts)) + { + nbAttempts--; + if (*(startLimit + longest) == *(ref - delta + longest)) + if (*(U32*)ref == *(U32*)ip) + { + const BYTE* reft = ref+MINMATCH; + const BYTE* ipt = ip+MINMATCH; + const BYTE* startt = ip; + + while (ipt<matchlimit-(STEPSIZE-1)) + { + UARCH diff = AARCH(reft) ^ AARCH(ipt); + if (!diff) { ipt+=STEPSIZE; reft+=STEPSIZE; continue; } + ipt += LZ4_NbCommonBytes(diff); + goto _endCount; + } + if (LZ4_ARCH64) if ((ipt<(matchlimit-3)) && (A32(reft) == A32(ipt))) { ipt+=4; reft+=4; } + if ((ipt<(matchlimit-1)) && (A16(reft) == A16(ipt))) { ipt+=2; 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 = ipt-startt; + *matchpos = reft; + *startpos = startt; + } + } + ref = GETNEXT(ref); + } + + return longest; +} + + +inline static int LZ4_encodeSequence(const BYTE** ip, BYTE** op, const BYTE** anchor, int ml, const BYTE* ref) +{ + int length, len; + BYTE* token; + + // Encode Literal length + length = *ip - *anchor; + token = (*op)++; + if (length>=(int)RUN_MASK) { *token=(RUN_MASK<<ML_BITS); len = length-RUN_MASK; for(; len > 254 ; len-=255) *(*op)++ = 255; *(*op)++ = (BYTE)len; } + else *token = (length<<ML_BITS); + + // Copy Literals + LZ4_BLINDCOPY(*anchor, *op, length); + + // Encode Offset + LZ4_WRITE_LITTLEENDIAN_16(*op,*ip-ref); + + // Encode MatchLength + len = (int)(ml-MINMATCH); + 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)++ = (BYTE)len; } + else *token += len; + + // Prepare next loop + *ip += ml; + *anchor = *ip; + + return 0; +} + + +//**************************** +// Compression CODE +//**************************** + +int LZ4_compressHCCtx(LZ4HC_Data_Structure* ctx, + const char* source, + char* dest, + int isize) +{ + const BYTE* ip = (const BYTE*) source; + const BYTE* anchor = ip; + const BYTE* const iend = ip + isize; + const BYTE* const mflimit = iend - MFLIMIT; + const BYTE* const matchlimit = (iend - LASTLITERALS); + + BYTE* op = (BYTE*) dest; + + int ml, ml2, ml3, ml0; + 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; + + ip++; + + // Main Loop + while (ip < mflimit) + { + ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, (&ref)); + if (!ml) { ip++; continue; } + + // saved, in case we would skip too much + start0 = ip; + ref0 = ref; + ml0 = ml; + +_Search2: + if (ip+ml < mflimit) + ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 1, matchlimit, ml, &ref2, &start2); + else ml2=ml; + + if (ml2 == ml) // No better match + { + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + continue; + } + + if (start0 < ip) + { + if (start2 < ip + ml0) // empirical + { + ip = start0; + ref = ref0; + ml = ml0; + } + } + + // Here, start0==ip + if ((start2 - ip) < 3) // First Match too small : removed + { + ml = ml2; + ip = start2; + ref =ref2; + goto _Search2; + } + +_Search3: + // 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 = start2 - ip + ml2 - MINMATCH; + correction = new_ml - (start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + // 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); + else ml3=ml2; + + if (ml3 == ml2) // No better match : 2 sequences to encode + { + // ip & ref are known; Now for ml + if (start2 < ip+ml) + { + if ((start2 - ip) < OPTIMAL_ML) + { + int correction; + if (ml > OPTIMAL_ML) ml = OPTIMAL_ML; + if (ip+ml > start2 + ml2 - MINMATCH) ml = start2 - ip + ml2 - MINMATCH; + correction = ml - (start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + else + { + ml = start2 - ip; + } + } + // Now, encode 2 sequences + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + ip = start2; + LZ4_encodeSequence(&ip, &op, &anchor, ml2, ref2); + continue; + } + + if (start3 < ip+ml+3) // 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 = (ip+ml) - start2; + start2 += correction; + ref2 += correction; + ml2 -= correction; + if (ml2 < MINMATCH) + { + start2 = start3; + ref2 = ref3; + ml2 = ml3; + } + } + + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + ip = start3; + ref = ref3; + ml = ml3; + + start0 = start2; + ref0 = ref2; + ml0 = ml2; + goto _Search2; + } + + start2 = start3; + ref2 = ref3; + ml2 = ml3; + goto _Search3; + } + + // 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 = start2 - ip + ml2 - MINMATCH; + correction = ml - (start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + else + { + ml = start2 - ip; + } + } + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + + ip = start2; + ref = ref2; + ml = ml2; + + start2 = start3; + ref2 = ref3; + ml2 = ml3; + + goto _Search3; + + } + + // Encode Last Literals + { + int lastRun = iend - anchor; + 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++ = (lastRun<<ML_BITS); + memcpy(op, anchor, iend - anchor); + op += iend-anchor; + } + + // End + return (int) (((char*)op)-dest); +} + + +int LZ4_compressHC(const char* source, + char* dest, + int isize) +{ + void* ctx = LZ4HC_Create((const BYTE*)source); + int result = LZ4_compressHCCtx(ctx, source, dest, isize); + LZ4HC_Free (&ctx); + + return result; +} + +int LZ4_contextHC_size(void) +{ + return sizeof(LZ4HC_Data_Structure); +} + +void LZ4_contextHC_init(void *ctx, const void *base) +{ + LZ4HC_Init(ctx, base); +} + + diff --git a/fs/btrfs/lz4hc.h b/fs/btrfs/lz4hc.h new file mode 100644 index 0000000..23ab176 --- /dev/null +++ b/fs/btrfs/lz4hc.h @@ -0,0 +1,58 @@ +/* + LZ4 HC - High Compression Mode of LZ4 + Copyright (C) 2011-2012, Yann Collet. + L-GPL v3 License + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License along + with this program; if not, see <http://www.gnu.org/licenses/>, + or write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + + You can contact the author at : + - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html + - LZ4-HC source repository : http://code.google.com/p/lz4hc/ +*/ +#pragma once + + +#if defined (__cplusplus) +extern "C" { +#endif + + +int LZ4_compressHC (const char* source, char* dest, int isize); + +/* +LZ4_compressHC : + return : the number of bytes in compressed buffer dest + note : destination buffer must be already allocated. + To avoid any problem, size it to handle worst cases situations (input data not compressible) + Worst case size evaluation is provided by function LZ4_compressBound() (see "lz4.h") +*/ + + +/* Note : +Decompression functions are provided within regular LZ4 source code (see "lz4.h") (BSD license) +*/ + +int LZ4_compressHCCtx(void* ctx, + const char* source, + char* dest, + int isize); + +int LZ4_contextHC_size(void); +void LZ4_contextHC_init(void *ctx, const void *base); + +#if defined (__cplusplus) +} +#endif -- 1.7.11 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
