diff options
Diffstat (limited to 'src/lib/lz4/lz4.c')
| -rw-r--r-- | src/lib/lz4/lz4.c | 863 |
1 files changed, 0 insertions, 863 deletions
diff --git a/src/lib/lz4/lz4.c b/src/lib/lz4/lz4.c deleted file mode 100644 index eeefa67..0000000 --- a/src/lib/lz4/lz4.c +++ /dev/null @@ -1,863 +0,0 @@ -/*
- 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
-//**************************************
-// 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
-#define MEMORY_USAGE 14
-
-// NOTCOMPRESSIBLE_DETECTIONLEVEL :
-// 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_DETECTIONLEVEL 6
-
-// BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
-// This will provide a small 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 remain 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
-# include <intrin.h> // For Visual 2005
-# 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 <stdlib.h> // for malloc
-#include <string.h> // 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 <stdint.h>
-# 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 (MEMORY_USAGE-2)
-#define HASHTABLESIZE (1 << HASH_LOG)
-#define HASH_MASK (HASHTABLESIZE - 1)
-
-#define SKIPSTRENGTH (NOTCOMPRESSIBLE_DETECTIONLEVEL>2?NOTCOMPRESSIBLE_DETECTIONLEVEL: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)
-
-
-//**************************************
-// 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
-
-static inline 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
-
-static inline 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
-
-
-
-//******************************
-// Compression functions
-//******************************
-
-// 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)
-{
-#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;
- BYTE* const oend = op + maxOutputSize;
-
- 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 = (int)(ip - anchor);
- token = op++;
- if unlikely(op + length + (2 + 1 + LASTLITERALS) + (length>>8) >= oend) return 0; // Check output limit
-#ifdef _MSC_VER
- if (length>=(int)RUN_MASK)
- {
- int len = length-RUN_MASK;
- *token=(RUN_MASK<<ML_BITS);
- if (len>254)
- {
- do { *op++ = 255; len -= 255; } while (len>254);
- *op++ = (BYTE)len;
- memcpy(op, anchor, length);
- op += length;
- goto _next_match;
- }
- else
- *op++ = (BYTE)len;
- }
- else *token = (length<<ML_BITS);
-#else
- 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);
-#endif
-
- // Copy Literals
- LZ4_BLINDCOPY(anchor, op, length);
-
-_next_match:
- // Encode Offset
- LZ4_WRITE_LITTLEENDIAN_16(op,(U16)(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 = (int)(ip - anchor);
- if unlikely(op + (1 + LASTLITERALS) + (len>>8) >= oend) return 0; // Check output limit
- 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 = (int)(iend - anchor);
- if (((char*)op - dest) + lastRun + 1 + ((lastRun-15)/255) >= maxOutputSize) 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))
-static inline int LZ4_compress64kCtx(void** ctx,
- const char* source,
- char* dest,
- int isize,
- int maxOutputSize)
-{
-#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;
- BYTE* const oend = op + maxOutputSize;
-
- 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] = (U16)(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 = (int)(ip - anchor);
- token = op++;
- if unlikely(op + length + (2 + 1 + LASTLITERALS) + (length>>8) >= oend) return 0; // Check output limit
-#ifdef _MSC_VER
- if (length>=(int)RUN_MASK)
- {
- int len = length-RUN_MASK;
- *token=(RUN_MASK<<ML_BITS);
- if (len>254)
- {
- do { *op++ = 255; len -= 255; } while (len>254);
- *op++ = (BYTE)len;
- memcpy(op, anchor, length);
- op += length;
- goto _next_match;
- }
- else
- *op++ = (BYTE)len;
- }
- else *token = (length<<ML_BITS);
-#else
- 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);
-#endif
-
- // Copy Literals
- LZ4_BLINDCOPY(anchor, op, length);
-
-_next_match:
- // Encode Offset
- LZ4_WRITE_LITTLEENDIAN_16(op,(U16)(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 = (int)(ip - anchor);
- if unlikely(op + (1 + LASTLITERALS) + (len>>8) >= oend) return 0; // Check output limit
- 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)] = (U16)(ip - 2 - 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; goto _next_match; }
-
- // Prepare next loop
- anchor = ip++;
- forwardH = LZ4_HASH64K_VALUE(ip);
- }
-
-_last_literals:
- // Encode Last Literals
- {
- int lastRun = (int)(iend - anchor);
- if (((char*)op - dest) + lastRun + 1 + ((lastRun)>>8) >= maxOutputSize) 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_limitedOutput(const char* source,
- char* dest,
- int isize,
- int maxOutputSize)
-{
-#if HEAPMODE
- void* ctx = malloc(sizeof(struct refTables));
- int result;
- if (isize < LZ4_64KLIMIT)
- result = LZ4_compress64kCtx(&ctx, source, dest, isize, maxOutputSize);
- else result = LZ4_compressCtx(&ctx, source, dest, isize, maxOutputSize);
- free(ctx);
- return result;
-#else
- if (isize < (int)LZ4_64KLIMIT) return LZ4_compress64kCtx(NULL, source, dest, isize, maxOutputSize);
- return LZ4_compressCtx(NULL, source, dest, isize, maxOutputSize);
-#endif
-}
-
-
-int LZ4_compress(const char* source,
- char* dest,
- int isize)
-{
- return LZ4_compress_limitedOutput(source, dest, isize, LZ4_compressBound(isize));
-}
-
-
-
-
-//****************************
-// 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; // 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-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; // Error : request to write beyond destination buffer
- 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; // 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 (ip<iend) goto _output_error; // Error : LZ4 format violation
- 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; // Error : offset creates reference outside of destination buffer
-
- // 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; // Error : request to write outside of destination buffer
- 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));
-}
-
|