diff options
Diffstat (limited to 'src/lib/lz4/lz4.c')
| -rw-r--r-- | src/lib/lz4/lz4.c | 819 |
1 files changed, 819 insertions, 0 deletions
diff --git a/src/lib/lz4/lz4.c b/src/lib/lz4/lz4.c new file mode 100644 index 0000000..06e2829 --- /dev/null +++ b/src/lib/lz4/lz4.c @@ -0,0 +1,819 @@ +/*
+ 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 <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 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)
+
+
+//**************************************
+// 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; // 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));
+}
+
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