Added : LZ4 HC : Now integrated into main trunk.

LZ4_HC license moved to BSD

git-svn-id: https://lz4.googlecode.com/svn/trunk@66 650e7d94-2a16-8b24-b05c-7c0b3f6821cd

1 files changed, 663 insertions, 0 deletions

diff --git a/lz4hc.c b/lz4hc.c
new file mode 100644
index 0000000..cca755c
--- /dev/null
+++ b/lz4hc.c
@@ -0,0 +1,663 @@
+/*

+   LZ4 HC - High Compression Mode of LZ4

+   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/

+*/

+

+

+//**************************************

+// 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 __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

+//**************************************

+#include <stdlib.h>   // calloc, free

+#include <string.h>   // memset, memcpy

+#include "lz4hc.h"

+

+#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

+#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 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;

+}

+

+