- New naming : LZ4_decompress_safe() and LZ4_decompress_fast()

- New function : LZ4_decompress_safe_partial(), to decompress just enough data within a compressed block, saving CPU cycles
- New source files : lz4_decoder.h, lz4_encoder.h, lz4hc_encoder.h
- Improved speed of LZ4_decompress_fast()
- Improved speed for compression of small blocks < 64KB
- Improved speed for HC compression

git-svn-id: https://lz4.googlecode.com/svn/trunk@94 650e7d94-2a16-8b24-b05c-7c0b3f6821cd

1 files changed, 241 insertions, 544 deletions

diff --git a/lz4.c b/lz4.c
index 2fac1a6..0cd962e 100644
--- a/lz4.c
+++ b/lz4.c
@@ -31,6 +31,10 @@
    - LZ4 source repository : http://code.google.com/p/lz4/

 */

 

+/*

+Note : this source file requires "lz4_encoder.h" and "lz4_decoder.h"

+*/

+

 //**************************************

 // Tuning parameters

 //**************************************

@@ -41,6 +45,12 @@
 // Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache

 #define MEMORY_USAGE 14

 

+// HEAPMODE :

+// Select if compression algorithm will allocate space for its tables

+// in memory stack (0:default, fastest), or in memory heap (1:requires memory allocation (malloc)).

+// Default allocation strategy is to use stack (HEAPMODE 0)

+#define HEAPMODE 0

+

 // 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

@@ -175,21 +185,18 @@ typedef struct _U64_S { U64 v; } U64_S;
 //**************************************

 // Constants

 //**************************************

-#define MINMATCH 4

+#define HASHTABLESIZE (1 << MEMORY_USAGE)

 

-#define HASH_LOG (MEMORY_USAGE-2)

-#define HASHTABLESIZE (1 << HASH_LOG)

-#define HASH_MASK (HASHTABLESIZE - 1)

+#define MINMATCH 4

 

-#define NOTCOMPRESSIBLE_DETECTIONLEVEL 6 // Increasing this value will make the algorithm slower on incompressible data

-#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 LZ4_64KLIMIT ((1<<16) + (MFLIMIT-1))

+#define SKIPSTRENGTH 6     // Increasing this value will make the compression run slower on incompressible data

+

 #define MAXD_LOG 16

 #define MAX_DISTANCE ((1 << MAXD_LOG) - 1)

 

@@ -232,19 +239,8 @@ typedef struct _U64_S { U64 v; } U64_S;
 

 

 //**************************************

-// 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; }

 

@@ -289,29 +285,29 @@ static inline int LZ4_NbCommonBytes (register U64 val)
 static inline int LZ4_NbCommonBytes (register U32 val)

 {

 #if defined(LZ4_BIG_ENDIAN)

-    #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)

+#  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)

+#  elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)

     return (__builtin_clz(val) >> 3);

-    #else

+#  else

     int r;

     if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }

     r += (!val);

     return r;

-    #endif

+#  endif

 #else

-    #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)

+#  if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT)

     unsigned long r;

     _BitScanForward( &r, val );

     return (int)(r>>3);

-    #elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)

+#  elif defined(__GNUC__) && (GCC_VERSION >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT)

     return (__builtin_ctz(val) >> 3);

-    #else

+#  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

 }

 

@@ -323,581 +319,282 @@ static inline int LZ4_NbCommonBytes (register U32 val)
 // 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,

+/*

+int LZ4_compress_stack(

                  const char* source,

                  char* dest,

-                 int inputSize,

-                 int maxOutputSize)

-{

-#if HEAPMODE

-    struct refTables *srt = (struct refTables *) (*ctx);

-    HTYPE* HashTable;

-#else

-    HTYPE HashTable[HASHTABLESIZE] = {0};

-#endif

+                 int inputSize)

 

-    const BYTE* ip = (BYTE*) source;

-    INITBASE(base);

-    const BYTE* anchor = ip;

-    const BYTE* const iend = ip + inputSize;

-    const BYTE* const mflimit = iend - MFLIMIT;

-#define matchlimit (iend - LASTLITERALS)

+Compress 'inputSize' bytes from 'source' into an output buffer 'dest'.

+Destination buffer must be already allocated, and sized at a minimum of LZ4_compressBound(inputSize).

+return : the number of bytes written in buffer 'dest'

+*/

+#define FUNCTION_NAME LZ4_compress_stack

+#include "lz4_encoder.h"

 

-    BYTE* op = (BYTE*) dest;

-    BYTE* const oend = op + maxOutputSize;

 

-    int length;

-    const int skipStrength = SKIPSTRENGTH;

-    U32 forwardH;

+/*

+int LZ4_compress_stack_limitedOutput(

+                 const char* source,

+                 char* dest,

+                 int inputSize,

+                 int maxOutputSize)

 

+Compress 'inputSize' 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

+*/

+#define FUNCTION_NAME LZ4_compress_stack_limitedOutput

+#define LIMITED_OUTPUT

+#include "lz4_encoder.h"

 

-    // Init

-    if (inputSize<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

 

+/*

+int LZ4_compress64k_stack(

+                 const char* source,

+                 char* dest,

+                 int inputSize)

 

-    // First Byte

-    HashTable[LZ4_HASH_VALUE(ip)] = (HTYPE)(ip - base);

-    ip++; forwardH = LZ4_HASH_VALUE(ip);

+Compress 'inputSize' bytes from 'source' into an output buffer 'dest'.

+This function compresses better than LZ4_compress_stack(), on the condition that

+'inputSize' must be < to LZ4_64KLIMIT, or the function will fail.

+Destination buffer must be already allocated, and sized at a minimum of LZ4_compressBound(inputSize).

+return : the number of bytes written in buffer 'dest', or 0 if compression fails

+*/

+#define FUNCTION_NAME LZ4_compress64k_stack

+#define COMPRESS_64K

+#include "lz4_encoder.h"

 

-    // 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;

+/*

+int LZ4_compress64k_stack_limitedOutput(

+                 const char* source,

+                 char* dest,

+                 int inputSize,

+                 int maxOutputSize)

 

-            if unlikely(forwardIp > mflimit) { goto _last_literals; }

+Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.

+This function compresses better than LZ4_compress_stack_limitedOutput(), on the condition that

+'inputSize' must be < to LZ4_64KLIMIT, or the function will fail.

+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

+*/

+#define FUNCTION_NAME LZ4_compress64k_stack_limitedOutput

+#define COMPRESS_64K

+#define LIMITED_OUTPUT

+#include "lz4_encoder.h"

 

-            forwardH = LZ4_HASH_VALUE(forwardIp);

-            ref = base + HashTable[h];

-            HashTable[h] = (HTYPE)(ip - base);

 

-        } while ((ref < ip - MAX_DISTANCE) || (A32(ref) != A32(ip)));

+/*

+void* LZ4_createHeapMemory();

+int LZ4_freeHeapMemory(void* ctx);

 

-        // Catch up

-        while ((ip>anchor) && (ref>(BYTE*)source) && unlikely(ip[-1]==ref[-1])) { ip--; ref--; }

+Used to allocate and free hashTable memory 

+to be used by the LZ4_compress_heap* family of functions.

+LZ4_createHeapMemory() returns NULL is memory allocation fails.

+*/

+void* LZ4_create() { return malloc(HASHTABLESIZE); }

+int LZ4_free(void* ctx) { free(ctx); return 0; }

 

-        // 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 = (BYTE)(length<<ML_BITS);

-#else

-        if (length>=(int)RUN_MASK) 

-        { 

-            int len;

-            *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 already 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

-        length = (int)(ip - anchor);

-        if unlikely(op + (1 + LASTLITERALS) + (length>>8) > oend) return 0; 		// Check output limit

-        if (length>=(int)ML_MASK) 

-        { 

-            *token += ML_MASK; 

-            length -= ML_MASK; 

-            for (; length > 509 ; length-=510) { *op++ = 255; *op++ = 255; } 

-            if (length > 254) { length-=255; *op++ = 255; } 

-            *op++ = (BYTE)length; 

-        }

-        else *token += (BYTE)length;

-

-        // Test end of chunk

-        if (ip > mflimit) { anchor = ip;  break; }

-

-        // Fill table

-        HashTable[LZ4_HASH_VALUE(ip-2)] = (HTYPE)(ip - 2 - base);

-

-        // Test next position

-        ref = base + HashTable[LZ4_HASH_VALUE(ip)];

-        HashTable[LZ4_HASH_VALUE(ip)] = (HTYPE)(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+255-RUN_MASK)/255) > (U32)maxOutputSize) return 0;  // Check output limit

-        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++ = (BYTE)(lastRun<<ML_BITS);

-        memcpy(op, anchor, iend - anchor);

-        op += iend-anchor;

-    }

-

-    // End

-    return (int) (((char*)op)-dest);

-}

+/*

+int LZ4_compress_heap(

+                 void* ctx,

+                 const char* source,

+                 char* dest,

+                 int inputSize)

 

+Compress 'inputSize' bytes from 'source' into an output buffer 'dest'.

+The memory used for compression must be created by LZ4_createHeapMemory() and provided by pointer 'ctx'.

+Destination buffer must be already allocated, and sized at a minimum of LZ4_compressBound(inputSize).

+return : the number of bytes written in buffer 'dest'

+*/

+#define FUNCTION_NAME LZ4_compress_heap

+#define USE_HEAPMEMORY

+#include "lz4_encoder.h"

 

 

-// 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,

+/*

+int LZ4_compress_heap_limitedOutput(

+                 void* ctx,

                  const char* source,

                  char* dest,

-                 int isize,

+                 int inputSize,

                  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

 

+Compress 'inputSize' 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.

+The memory used for compression must be created by LZ4_createHeapMemory() and provided by pointer 'ctx'.

+return : the number of bytes written in buffer 'dest', or 0 if the compression fails

+*/

+#define FUNCTION_NAME LZ4_compress_heap_limitedOutput

+#define LIMITED_OUTPUT

+#define USE_HEAPMEMORY

+#include "lz4_encoder.h"

 

-    // 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;

+/*

+int LZ4_compress64k_heap(

+                 void* ctx,

+                 const char* source,

+                 char* dest,

+                 int inputSize)

 

-        // Find a match

-        do {

-            U32 h = forwardH;

-            int step = findMatchAttempts++ >> skipStrength;

-            ip = forwardIp;

-            forwardIp = ip + step;

+Compress 'inputSize' bytes from 'source' into an output buffer 'dest'.

+The memory used for compression must be created by LZ4_createHeapMemory() and provided by pointer 'ctx'.

+'inputSize' must be < to LZ4_64KLIMIT, or the function will fail.

+Destination buffer must be already allocated, and sized at a minimum of LZ4_compressBound(inputSize).

+return : the number of bytes written in buffer 'dest'

+*/

+#define FUNCTION_NAME LZ4_compress64k_heap

+#define COMPRESS_64K

+#define USE_HEAPMEMORY

+#include "lz4_encoder.h"

 

-            if (forwardIp > mflimit) { goto _last_literals; }

 

-            forwardH = LZ4_HASH64K_VALUE(forwardIp);

-            ref = base + HashTable[h];

-            HashTable[h] = (U16)(ip - base);

+/*

+int LZ4_compress64k_heap_limitedOutput(

+                 void* ctx,

+                 const char* source,

+                 char* dest,

+                 int inputSize,

+                 int maxOutputSize)

 

-        } while (A32(ref) != A32(ip));

+Compress 'inputSize' 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.

+The memory used for compression must be created by LZ4_createHeapMemory() and provided by pointer 'ctx'.

+'inputSize' must be < to LZ4_64KLIMIT, or the function will fail.

+return : the number of bytes written in buffer 'dest', or 0 if the compression fails

+*/

+#define FUNCTION_NAME LZ4_compress64k_heap_limitedOutput

+#define COMPRESS_64K

+#define LIMITED_OUTPUT

+#define USE_HEAPMEMORY

+#include "lz4_encoder.h"

 

-        // 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 = (BYTE)(length<<ML_BITS);

+int LZ4_compress(const char* source, char* dest, int inputSize)

+{

+#if HEAPMODE

+    void* ctx = LZ4_create();

+    int result;

+    if (ctx == NULL) return 0;    // Failed allocation => compression not done

+    if (inputSize < LZ4_64KLIMIT)

+        result = LZ4_compress64k_heap(ctx, source, dest, inputSize);

+    else result = LZ4_compress_heap(ctx, source, dest, inputSize);

+    LZ4_free(ctx);

+    return result;

 #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);

+    if (inputSize < (int)LZ4_64KLIMIT) return LZ4_compress64k_stack(source, dest, inputSize);

+    return LZ4_compress_stack(source, dest, inputSize);

 #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 += (BYTE)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 (op + lastRun + 1 + (lastRun-RUN_MASK+255)/255 > oend) 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++ = (BYTE)(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)

+int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)

 {

 #if HEAPMODE

-    void* ctx = malloc(sizeof(struct refTables));

+    void* ctx = LZ4_create();

     int result;

     if (ctx == NULL) return 0;    // Failed allocation => compression not done

-    if (isize < LZ4_64KLIMIT)

-        result = LZ4_compress64kCtx(&ctx, source, dest, isize, maxOutputSize);

-    else result = LZ4_compressCtx(&ctx, source, dest, isize, maxOutputSize);

-    free(ctx);

+    if (inputSize < LZ4_64KLIMIT)

+        result = LZ4_compress64k_heap_limitedOutput(ctx, source, dest, inputSize, maxOutputSize);

+    else result = LZ4_compress_heap_limitedOutput(ctx, source, dest, inputSize, maxOutputSize);

+    LZ4_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);

+    if (inputSize < (int)LZ4_64KLIMIT) return LZ4_compress64k_stack_limitedOutput(source, dest, inputSize, maxOutputSize);

+    return LZ4_compress_stack_limitedOutput(source, dest, inputSize, 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.

-//      LZ4_uncompress() guarantees that it will never read before source, nor beyond source + LZ4_compressBound(osize)

-//		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* ref;

-

-    BYTE* op = (BYTE*) dest;

-    BYTE* const oend = op + osize;

-    BYTE* cpy;

-

-    unsigned token;

+/*

+int LZ4_decompress_safe(const char* source,

+                        char* dest,

+                        int inputSize,

+                        int maxOutputSize);

+

+LZ4_decompress_safe() guarantees it will never write nor read outside of the provided output buffers.

+This function is safe against "buffer overflow" attacks.

+A corrupted input will produce an error result, a negative int.

+*/

+#define FUNCTION_NAME LZ4_decompress_safe

+#define EXITCONDITION_INPUTSIZE

+#include "lz4_decoder.h"

 

-    size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};

-#if LZ4_ARCH64

-    size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};

-#endif

 

+/*

+int LZ4_decompress_safe_withPrefix64k(

+                        const char* source,

+                        char* dest,

+                        int inputSize,

+                        int maxOutputSize);

+

+Same as LZ4_decompress_safe(), but will also use 64K of memory before the beginning of input buffer.

+Typically used to decode streams of inter-dependant blocks.

+Note : the 64K of memory before pointer 'source' must be allocated and read-allowed.

+*/

+#define FUNCTION_NAME LZ4_decompress_safe_withPrefix64k

+#define EXITCONDITION_INPUTSIZE

+#define PREFIX_64K

+#include "lz4_decoder.h"

 

-    // Main Loop

-    while (1)

-    {

-        size_t length;

-

-        // get runlength

-        token = *ip++;

-        if ((length=(token>>ML_BITS)) == RUN_MASK)  { size_t len; for (;(len=*ip++)==255;length+=255){} length += len; }

-

-        // copy literals

-        cpy = op+length;

-        if (cpy>oend-COPYLENGTH)

-        {

-            if (cpy != oend) goto _output_error;         // Error : not enough place for another match (min 4) + 5 literals

-            memcpy(op, ip, length);

-            ip += length;

-            break;                                       // EOF

-        }

-        LZ4_WILDCOPY(ip, op, cpy); ip -= (op-cpy); op = cpy;

-

-        // get offset

-        LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;

-        if unlikely(ref < (BYTE* const)dest) goto _output_error;   // Error : offset 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 dec64 = dec64table[op-ref];

-#else

-            const int dec64 = 0;

-#endif

-            op[0] = ref[0];

-            op[1] = ref[1];

-            op[2] = ref[2];

-            op[3] = ref[3];

-            op += 4, ref += 4; ref -= dec32table[op-ref];

-            A32(op) = A32(ref); 

-            op += STEPSIZE-4; ref -= dec64;

-        } else { LZ4_COPYSTEP(ref,op); }

-        cpy = op + length - (STEPSIZE-4);

-

-        if unlikely(cpy>oend-(COPYLENGTH)-(STEPSIZE-4))

-        {

-            if (cpy > oend-LASTLITERALS) goto _output_error;    // Error : last 5 bytes must be literals

-            LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH));

-            while(op<cpy) *op++=*ref++;

-            op=cpy;

-            continue;

-        }

-        

-        LZ4_WILDCOPY(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_decompress_safe_partial(

+                        const char* source,

+                        char* dest,

+                        int inputSize,

+                        int targetOutputSize,

+                        int maxOutputSize);

+

+LZ4_decompress_safe_partial() objective is to decompress only a part of the compressed input block provided.

+The decoding process stops as soon as 'targetOutputSize' bytes have been decoded, reducing decoding time.

+The result of the function is the number of bytes decoded.

+LZ4_decompress_safe_partial() may decode less than 'targetOutputSize' if input doesn't contain enough bytes to decode.

+Always verify how many bytes were decoded to ensure there are as many as wanted into the output buffer 'dest'.

+A corrupted input will produce an error result, a negative int.

+*/

+#define FUNCTION_NAME LZ4_decompress_safe_partial

+#define EXITCONDITION_INPUTSIZE

+#define PARTIAL_DECODING

+#include "lz4_decoder.h"

 

-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* ref;

 

-    BYTE* op = (BYTE*) dest;

-    BYTE* const oend = op + maxOutputSize;

-    BYTE* cpy;

+/*

+int LZ4_decompress_fast(const char* source,

+                        char* dest,

+                        int outputSize);

+

+This function is faster than LZ4_decompress_safe().

+LZ4_decompress_fast() guarantees it will never write nor read outside of output buffer.

+Since LZ4_decompress_fast() doesn't know the size of input buffer.

+it can only guarantee that it will never write into the input buffer, and will never read before its beginning.

+To be used preferably in a controlled environment (when the compressed data to be decoded is from a trusted source).

+A detected corrupted input will produce an error result, a negative int.

+*/

+#define FUNCTION_NAME LZ4_decompress_fast

+#include "lz4_decoder.h"

 

-    size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};

-#if LZ4_ARCH64

-    size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};

-#endif

 

+/*

+int LZ4_decompress_fast_withPrefix64k(

+                        const char* source,

+                        char* dest,

+                        int inputSize

+                        int maxOutputSize);

+

+Same as LZ4_decompress_fast(), but will use the 64K of memory before the beginning of input buffer.

+Typically used to decode streams of dependant inter-blocks.

+Note : the 64K of memory before pointer 'source' must be allocated and read-allowed.

+*/

+#define FUNCTION_NAME LZ4_decompress_fast_withPrefix64k

+#define PREFIX_64K

+#include "lz4_decoder.h"

 

-    // Special case

-    if unlikely(ip==iend) goto _output_error;    // A correctly formed null-compressed LZ4 must have at least one byte (token=0)

-

-    // Main Loop

-    while (1) 

-    {

-        unsigned token;

-        size_t length;

-

-        // get runlength

-        token = *ip++;

-        if ((length=(token>>ML_BITS)) == RUN_MASK) 

-        { 

-            int s=255; 

-            while (likely(ip<iend) && (s==255)) { s=*ip++; length += s; } 

-        }

-

-        // copy literals

-        cpy = op+length;

-        if ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS)))

-        {

-            if (cpy > oend) goto _output_error;          // Error : writes beyond output buffer

-            if (ip+length != iend) goto _output_error;   // Error : LZ4 format requires to consume all input at this stage (no match within the last 11 bytes, and at least 8 remaining input bytes for another match+literals)

-            memcpy(op, ip, length);

-            op += length;

-            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 unlikely(ref < (BYTE* const)dest) goto _output_error;   // Error : offset outside of destination buffer

-

-        // get matchlength

-        if ((length=(token&ML_MASK)) == ML_MASK)    

-        { 

-            while likely(ip<iend-(LASTLITERALS+1))    // Error : a minimum input bytes must remain for LASTLITERALS + token

-            { 

-                int s = *ip++; 

-                length +=s; 

-                if (s==255) continue; 

-                break; 

-            } 

-        }

-

-        // copy repeated sequence

-        if unlikely(op-ref<STEPSIZE)

-        {

-#if LZ4_ARCH64

-            size_t dec64 = dec64table[op-ref];

-#else

-            const int dec64 = 0;

-#endif

-            op[0] = ref[0];

-            op[1] = ref[1];

-            op[2] = ref[2];

-            op[3] = ref[3];

-            op += 4, ref += 4; ref -= dec32table[op-ref];

-            A32(op) = A32(ref); 

-            op += STEPSIZE-4; ref -= dec64;

-        } else { LZ4_COPYSTEP(ref,op); }

-        cpy = op + length - (STEPSIZE-4);

-

-        if unlikely(cpy>oend-(COPYLENGTH+(STEPSIZE-4)))

-        {

-            if (cpy > oend-LASTLITERALS) goto _output_error;    // Error : last 5 bytes must be literals

-            LZ4_SECURECOPY(ref, op, (oend-COPYLENGTH));

-            while(op<cpy) *op++=*ref++;

-            op=cpy;

-            continue;

-        }

-

-        LZ4_WILDCOPY(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));

-}