Updated LZ4 http://lz4.googlecode.com/svn/trunk/ rev. 62 [#CONV-4593].

This commit is contained in:
Alexey Milovidov 2012-04-14 00:09:30 +00:00
parent 5a36e4bce3
commit 65b1caa9d7
2 changed files with 429 additions and 190 deletions

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@ -27,6 +27,7 @@
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#if defined (__cplusplus)
extern "C" {
@ -37,22 +38,24 @@ extern "C" {
// Simple Functions
//****************************
int LZ4_compress (char* source, char* dest, int isize);
int LZ4_uncompress (char* source, char* dest, int osize);
int LZ4_compress (const char* source, char* dest, int isize);
int LZ4_uncompress (const char* source, char* dest, int osize);
/*
LZ4_compress :
return : the number of bytes in compressed buffer dest
LZ4_compress() :
isize : is the input size. Max supported value is ~1.9GB
return : the number of bytes written in buffer dest
or 0 if the compression fails (if LZ4_COMPRESSMIN is set)
note : destination buffer must be already allocated.
To avoid any problem, size it to handle worst cases situations (input data not compressible)
Worst case size is : "inputsize + 0.4%", with "0.4%" being at least 8 bytes.
destination buffer must be sized to handle worst cases situations (input data not compressible)
worst case size evaluation is provided by function LZ4_compressBound()
LZ4_uncompress :
LZ4_uncompress() :
osize : is the output size, therefore the original size
return : the number of bytes read in the source buffer
If the source stream is malformed, the function will stop decoding and return a negative result, indicating the byte position of the faulty instruction
This version never writes beyond dest + osize, and is therefore protected against malicious data packets
note 2 : destination buffer must be already allocated
This function never writes beyond dest + osize, and is therefore protected against malicious data packets
note : destination buffer must be already allocated
*/
@ -60,33 +63,50 @@ LZ4_uncompress :
// Advanced Functions
//****************************
int LZ4_uncompress_unknownOutputSize (char* source, char* dest, int isize, int maxOutputSize);
int LZ4_compressBound(int isize);
/*
LZ4_uncompress_unknownOutputSize :
LZ4_compressBound() :
Provides the maximum size that LZ4 may output in a "worst case" scenario (input data not compressible)
primarily useful for memory allocation of output buffer.
isize : is the input size. Max supported value is ~1.9GB
return : maximum output size in a "worst case" scenario
note : this function is limited by "int" range (2^31-1)
*/
int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize);
/*
LZ4_uncompress_unknownOutputSize() :
isize : is the input size, therefore the compressed size
maxOutputSize : is the size of the destination buffer (which must be already allocated)
return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize)
If the source stream is malformed, the function will stop decoding and return a negative result, indicating the byte position of the faulty instruction
This version never writes beyond dest + maxOutputSize, and is therefore protected against malicious data packets
note : This version is slower than LZ4_uncompress, and is therefore not recommended for general use
This function never writes beyond dest + maxOutputSize, and is therefore protected against malicious data packets
note : This version is slightly slower than LZ4_uncompress()
*/
int LZ4_compressCtx(void** ctx, char* source, char* dest, int isize);
int LZ4_compressCtx(void** ctx, const char* source, char* dest, int isize);
int LZ4_compress64kCtx(void** ctx, const char* source, char* dest, int isize);
/*
LZ4_compressCtx :
LZ4_compressCtx() :
This function explicitly handles the CTX memory structure.
It avoids allocating/deallocating memory between each call, improving performance when malloc is time-consuming.
Note : when memory is allocated into the stack (default mode), there is no "malloc" penalty.
Therefore, this function is mostly useful when memory is allocated into the heap (it requires increasing HASH_LOG value beyond STACK_LIMIT)
It avoids allocating/deallocating memory between each call, improving performance when malloc is heavily invoked.
This function is only useful when memory is allocated into the heap (HASH_LOG value beyond STACK_LIMIT)
Performance difference will be noticeable only when repetitively calling the compression function over many small segments.
Note : by default, memory is allocated into the stack, therefore "malloc" is not invoked.
LZ4_compress64kCtx() :
Same as LZ4_compressCtx(), but specific to small inputs (<64KB).
isize *Must* be <64KB, otherwise the output will be corrupted.
On first call : provide a *ctx=NULL; It will be automatically allocated.
On next calls : reuse the same ctx pointer.
Use different pointers for different threads when doing multi-threading.
note : performance difference is small, mostly noticeable when repetitively calling the compression algorithm on many small segments.
*/

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@ -1,7 +1,7 @@
/*
LZ4 - Fast LZ compression algorithm
Copyright (C) 2011, Yann Collet.
BSD License
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
@ -27,6 +27,100 @@
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
//**************************************
// Tuning parameters
//**************************************
// COMPRESSIONLEVEL :
// Increasing this value improves compression ratio
// Lowering this value reduces memory usage
// Reduced memory usage typically improves speed, due to cache effect (ex : L1 32KB for Intel, L1 64KB for AMD)
// Memory usage formula : N->2^(N+2) Bytes (examples : 12 -> 16KB ; 17 -> 512KB)
#define COMPRESSIONLEVEL 12
// NOTCOMPRESSIBLE_CONFIRMATION :
// Decreasing this value will make the algorithm skip faster data segments considered "incompressible"
// This may decrease compression ratio dramatically, but will be faster on incompressible data
// Increasing this value will make the algorithm search more before declaring a segment "incompressible"
// This could improve compression a bit, but will be slower on incompressible data
// The default value (6) is recommended
#define NOTCOMPRESSIBLE_CONFIRMATION 6
// LZ4_COMPRESSMIN :
// Compression function will *fail* if it is not successful at compressing input by at least LZ4_COMPRESSMIN bytes
// Since the compression function stops working prematurely, it results in a speed gain
// The output however is unusable. Compression function result will be zero.
// Default : 0 = disabled
#define LZ4_COMPRESSMIN 0
// BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
// This will provide a boost to performance for big endian cpu, but the resulting compressed stream will be incompatible with little-endian CPU.
// You can set this option to 1 in situations where data will stay within closed environment
// This option is useless on Little_Endian CPU (such as x86)
//#define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1
//**************************************
// CPU Feature Detection
//**************************************
// 32 or 64 bits ?
#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) || defined(__amd64) || defined(__ppc64__) || defined(_WIN64) || defined(__LP64__) || defined(_LP64) ) // Detects 64 bits mode
#define LZ4_ARCH64 1
#else
#define LZ4_ARCH64 0
#endif
// Little Endian or Big Endian ?
#if (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || defined(_BIG_ENDIAN) || defined(_ARCH_PPC) || defined(__PPC__) || defined(__PPC) || defined(PPC) || defined(__powerpc__) || defined(__powerpc) || defined(powerpc) || ((defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))) )
#define LZ4_BIG_ENDIAN 1
#else
// Little Endian assumed. PDP Endian and other very rare endian format are unsupported.
#endif
// Unaligned memory access is automatically enabled for "common" CPU, such as x86.
// For others CPU, the compiler will be more cautious, and insert extra code to ensure aligned access is respected
// If you know your target CPU supports unaligned memory access, you may want to force this option manually to improve performance
#if defined(__ARM_FEATURE_UNALIGNED)
#define LZ4_FORCE_UNALIGNED_ACCESS 1
#endif
// Uncomment this parameter if your target system or compiler does not support hardware bit count
//#define LZ4_FORCE_SW_BITCOUNT
//**************************************
// Compiler Options
//**************************************
#if __STDC_VERSION__ >= 199901L // C99
/* "restrict" is a known keyword */
#else
#define restrict // Disable restrict
#endif
#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
#ifdef _MSC_VER // Visual Studio
#define inline __forceinline // Visual is not C99, but supports some kind of inline
#include <intrin.h> // _BitScanForward
#endif
#ifdef _MSC_VER
#define lz4_bswap16(x) _byteswap_ushort(x)
#else
#define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
#endif
#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
# define expect(expr,value) (__builtin_expect ((expr),(value)) )
#else
# define expect(expr,value) (expr)
#endif
#define likely(expr) expect((expr) != 0, 1)
#define unlikely(expr) expect((expr) != 0, 0)
//**************************************
// Includes
//**************************************
@ -35,41 +129,53 @@
#include <lz4/lz4.h>
//**************************************
// Performance parameter
//**************************************
// Increasing this value improves compression ratio
// Lowering this value reduces memory usage
// Lowering may also improve speed, typically on reaching cache size limits (L1 32KB for Intel, 64KB for AMD)
// Memory usage formula for 32 bits systems : N->2^(N+2) Bytes (examples : 17 -> 512KB ; 12 -> 16KB)
#define HASH_LOG 12
//**************************************
// Basic Types
//**************************************
#if defined(_MSC_VER)
#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 SKIPSTRENGTH 6
#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 COPYTOKEN 4
#define COPYLENGTH 8
#define LASTLITERALS 5
#define MFLIMIT (COPYLENGTH+MINMATCH)
@ -78,71 +184,160 @@
#define MAXD_LOG 16
#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
#define HASHTABLESIZE (1 << HASH_LOG)
#define HASH_MASK (HASHTABLESIZE - 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
{
const BYTE* hashTable[HASHTABLESIZE];
HTYPE hashTable[HASHTABLESIZE];
};
#ifdef __GNUC__
# define _PACKED __attribute__ ((packed))
#else
# define _PACKED
#endif
typedef struct _U32_S
{
U32 v;
} _PACKED U32_S;
typedef struct _U16_S
{
U16 v;
} _PACKED U16_S;
#define A32(x) (((U32_S *)(x))->v)
#define A16(x) (((U16_S *)(x))->v)
//**************************************
// Macros
//**************************************
#define LZ4_HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8)-HASH_LOG))
#define LZ4_HASH_VALUE(p) LZ4_HASH_FUNCTION(A32(p))
#define LZ4_COPYPACKET(s,d) A32(d) = A32(s); d+=4; s+=4; A32(d) = A32(s); d+=4; s+=4;
#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 LZ4_BLINDCOPY(s,d,l) { BYTE* e=(d)+l; LZ4_WILDCOPY(s,d,e); d=e; }
//****************************
// Compression CODE
// 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,
char* source,
const char* source,
char* dest,
int isize)
{
#if HEAPMODE
struct refTables *srt = (struct refTables *) (*ctx);
const BYTE** HashTable;
HTYPE* HashTable;
#else
const BYTE* HashTable[HASHTABLESIZE] = {0};
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;
@ -163,7 +358,7 @@ int LZ4_compressCtx(void** ctx,
srt = (struct refTables *) malloc ( sizeof(struct refTables) );
*ctx = (void*) srt;
}
HashTable = srt->hashTable;
HashTable = (HTYPE*)(srt->hashTable);
memset((void*)HashTable, 0, sizeof(srt->hashTable));
#else
(void) ctx;
@ -171,7 +366,7 @@ int LZ4_compressCtx(void** ctx,
// First Byte
HashTable[LZ4_HASH_VALUE(ip)] = ip;
HashTable[LZ4_HASH_VALUE(ip)] = ip - base;
ip++; forwardH = LZ4_HASH_VALUE(ip);
// Main Loop
@ -189,16 +384,16 @@ int LZ4_compressCtx(void** ctx,
ip = forwardIp;
forwardIp = ip + step;
if (forwardIp > mflimit) { goto _last_literals; }
if unlikely(forwardIp > mflimit) { goto _last_literals; }
forwardH = LZ4_HASH_VALUE(forwardIp);
ref = HashTable[h];
HashTable[h] = ip;
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) && (ip[-1]==ref[-1])) { ip--; ref--; }
while ((ip>anchor) && (ref>(BYTE*)source) && unlikely(ip[-1]==ref[-1])) { ip--; ref--; }
// Encode Literal length
length = ip - anchor;
@ -209,24 +404,27 @@ int LZ4_compressCtx(void** ctx,
// Copy Literals
LZ4_BLINDCOPY(anchor, op, length);
_next_match:
// Encode Offset
A16(op) = (ip-ref); op+=2;
LZ4_WRITE_LITTLEENDIAN_16(op,ip-ref);
// Start Counting
ip+=MINMATCH; ref+=MINMATCH; // MinMatch verified
anchor = ip;
while (A32(ref) == A32(ip))
while likely(ip<matchlimit-(STEPSIZE-1))
{
ip+=4; ref+=4;
if (ip>matchlimit-4) { ref -= ip - (matchlimit-3); ip = matchlimit-3; break; }
UARCH diff = AARCH(ref) ^ AARCH(ip);
if (!diff) { ip+=STEPSIZE; ref+=STEPSIZE; continue; }
ip += LZ4_NbCommonBytes(diff);
goto _endCount;
}
if (A16(ref) == A16(ip)) { ip+=2; ref+=2; }
if (*ref == *ip) ip++;
len = (ip - anchor);
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;
@ -234,11 +432,11 @@ _next_match:
if (ip > mflimit) { anchor = ip; break; }
// Fill table
HashTable[LZ4_HASH_VALUE(ip-2)] = ip-2;
HashTable[LZ4_HASH_VALUE(ip-2)] = ip - 2 - base;
// Test next position
ref = HashTable[LZ4_HASH_VALUE(ip)];
HashTable[LZ4_HASH_VALUE(ip)] = ip;
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
@ -250,6 +448,7 @@ _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);
@ -263,12 +462,13 @@ _last_literals:
// Note : this function is valid only if isize < LZ4_64KLIMIT
#define LZ4_64KLIMIT ((1U<<16) + (MFLIMIT-1))
#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,
char* source,
const char* source,
char* dest,
int isize)
{
@ -276,7 +476,7 @@ int LZ4_compress64kCtx(void** ctx,
struct refTables *srt = (struct refTables *) (*ctx);
U16* HashTable;
#else
U16 HashTable[HASHTABLESIZE<<1] = {0};
U16 HashTable[HASH64KTABLESIZE] = {0};
#endif
const BYTE* ip = (BYTE*) source;
@ -346,37 +546,40 @@ int LZ4_compress64kCtx(void** ctx,
// Copy Literals
LZ4_BLINDCOPY(anchor, op, length);
_next_match:
// Encode Offset
A16(op) = (ip-ref); op+=2;
LZ4_WRITE_LITTLEENDIAN_16(op,ip-ref);
// Start Counting
ip+=MINMATCH; ref+=MINMATCH; // MinMatch verified
anchor = ip;
while (ip<matchlimit-3)
while (ip<matchlimit-(STEPSIZE-1))
{
if (A32(ref) == A32(ip)) { ip+=4; ref+=4; continue; }
if (A16(ref) == A16(ip)) { ip+=2; ref+=2; }
if (*ref == *ip) ip++;
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:
len = (ip - anchor);
// 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 ((ref > ip - (MAX_DISTANCE + 1)) && (A32(ref) == A32(ip))) { token = op++; *token=0; goto _next_match; }
if (A32(ref) == A32(ip)) { token = op++; *token=0; goto _next_match; }
// Prepare next loop
anchor = ip++;
@ -387,6 +590,7 @@ _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);
@ -399,7 +603,7 @@ _last_literals:
int LZ4_compress(char* source,
int LZ4_compress(const char* source,
char* dest,
int isize)
{
@ -421,31 +625,31 @@ int LZ4_compress(char* source,
//****************************
// Decompression CODE
// Decompression functions
//****************************
// Note : The decoding functions LZ4_uncompress() and LZ4_uncompress_unknownOutputSize()
// are safe against "buffer overflow" attack type
// since they will *never* write outside of the provided output buffer :
// they both check this condition *before* writing anything.
// A corrupted packet however can make them *read* within the first 64K before the output buffer.
// 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(char* source,
int LZ4_uncompress(const char* source,
char* dest,
int osize)
{
// Local Variables
const BYTE* ip = (const BYTE*) source;
BYTE* ref;
const BYTE* restrict ip = (const BYTE*) source;
const BYTE* restrict ref;
BYTE* op = (BYTE*) dest;
BYTE* restrict op = (BYTE*) dest;
BYTE* const oend = op + osize;
BYTE* cpy;
BYTE token;
U32 dec[4]={0, 3, 2, 3};
int len, length;
size_t dec[] ={0, 3, 2, 3, 0, 0, 0, 0};
// Main Loop
@ -456,44 +660,51 @@ int LZ4_uncompress(char* source,
if ((length=(token>>ML_BITS)) == RUN_MASK) { for (;(len=*ip++)==255;length+=255){} length += len; }
// copy literals
ref = op+length;
if (ref>oend-COPYLENGTH)
cpy = op+length;
if unlikely(cpy>oend-COPYLENGTH)
{
if (ref > oend) goto _output_error;
if (cpy > oend) goto _output_error;
memcpy(op, ip, length);
ip += length;
break; // Necessarily EOF
}
LZ4_WILDCOPY(ip, op, ref); ip -= (op-ref); op = ref;
LZ4_WILDCOPY(ip, op, cpy); ip -= (op-cpy); op = cpy;
// get offset
ref -= A16(ip); ip+=2;
LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
if (ref < (BYTE* const)dest) goto _output_error;
// get matchlength
if ((length=(token&ML_MASK)) == ML_MASK) { for (;*ip==255;length+=255) {ip++;} length += *ip++; }
// copy repeated sequence
if (op-ref<COPYTOKEN)
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);
} else { A32(op)=A32(ref); op+=4; ref+=4; }
cpy = op + length;
if (cpy > oend-COPYLENGTH)
A32(op)=A32(ref); op += STEPSIZE-4;
ref -= dec2;
} else { LZ4_COPYSTEP(ref,op); }
cpy = op + length - (STEPSIZE-4);
if (cpy>oend-COPYLENGTH)
{
if (cpy > oend) goto _output_error;
LZ4_WILDCOPY(ref, op, (oend-COPYLENGTH));
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_WILDCOPY(ref, op, cpy);
LZ4_SECURECOPY(ref, op, cpy);
op=cpy; // correction
}
@ -507,73 +718,82 @@ _output_error:
int LZ4_uncompress_unknownOutputSize(
char* source,
const char* source,
char* dest,
int isize,
int maxOutputSize)
{
// Local Variables
const BYTE* ip = (const BYTE*) source;
const BYTE* restrict ip = (const BYTE*) source;
const BYTE* const iend = ip + isize;
BYTE* ref;
const BYTE* restrict ref;
BYTE* op = (BYTE*) dest;
BYTE* restrict op = (BYTE*) dest;
BYTE* const oend = op + maxOutputSize;
BYTE* cpy;
BYTE token;
U32 dec[COPYTOKEN]={0, 3, 2, 3};
int len, length;
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) { for (;(len=*ip++)==255;length+=255){} length += len; }
if ((length=(token>>ML_BITS)) == RUN_MASK) { int s=255; while ((ip<iend) && (s==255)) { s=*ip++; length += s; } }
// copy literals
ref = op+length;
if (ref>oend-COPYLENGTH)
cpy = op+length;
if ((cpy>oend-COPYLENGTH) || (ip+length>iend-COPYLENGTH))
{
if (ref > oend) goto _output_error;
if (cpy > oend) goto _output_error;
if (ip+length > iend) goto _output_error;
memcpy(op, ip, length);
op += length;
ip += length;
break; // Necessarily EOF
if (ip<iend) goto _output_error;
break; // Necessarily EOF, due to parsing restrictions
}
LZ4_WILDCOPY(ip, op, ref); ip -= (op-ref); op = ref;
if (ip>=iend) break; // check EOF
LZ4_WILDCOPY(ip, op, cpy); ip -= (op-cpy); op = cpy;
// get offset
ref -= A16(ip); ip+=2;
LZ4_READ_LITTLEENDIAN_16(ref,cpy,ip); ip+=2;
if (ref < (BYTE* const)dest) goto _output_error;
// get matchlength
if ((length=(token&ML_MASK)) == ML_MASK) { for (;(len=*ip++)==255;length+=255){} length += len; }
if ((length=(token&ML_MASK)) == ML_MASK) { while (ip<iend) { int s = *ip++; length +=s; if (s==255) continue; break; } }
// copy repeated sequence
if (op-ref<COPYTOKEN)
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);
} else { A32(op)=A32(ref); op+=4; ref+=4; }
cpy = op + length;
A32(op)=A32(ref); op += STEPSIZE-4;
ref -= dec2;
} else { LZ4_COPYSTEP(ref,op); }
cpy = op + length - (STEPSIZE-4);
if (cpy>oend-COPYLENGTH)
{
if (cpy > oend) goto _output_error;
LZ4_WILDCOPY(ref, op, (oend-COPYLENGTH));
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_WILDCOPY(ref, op, cpy);
LZ4_SECURECOPY(ref, op, cpy);
op=cpy; // correction
}
@ -585,4 +805,3 @@ _output_error:
return (int) (-(((char*)ip)-source));
}