444 lines
10 KiB
C
444 lines
10 KiB
C
|
/*
|
||
|
|
* 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/
|
||
|
|
*
|
||
|
|
* Changed for kernel use by:
|
||
|
|
* Chanho Min <chanho.min@lge.com>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/lz4.h>
|
||
|
|
#include <asm/unaligned.h>
|
||
|
|
#include "lz4defs.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* LZ4_compressCtx :
|
||
|
|
* -----------------
|
||
|
|
* Compress 'isize' bytes from 'source' into an output buffer 'dest' of
|
||
|
|
* maximum size 'maxOutputSize'. * If it cannot achieve it, compression
|
||
|
|
* will stop, and result of the function will be zero.
|
||
|
|
* return : the number of bytes written in buffer 'dest', or 0 if the
|
||
|
|
* compression fails
|
||
|
|
*/
|
||
|
|
static inline int lz4_compressctx(void *ctx,
|
||
|
|
const char *source,
|
||
|
|
char *dest,
|
||
|
|
int isize,
|
||
|
|
int maxoutputsize)
|
||
|
|
{
|
||
|
|
HTYPE *hashtable = (HTYPE *)ctx;
|
||
|
|
const u8 *ip = (u8 *)source;
|
||
|
|
#if LZ4_ARCH64
|
||
|
|
const BYTE * const base = ip;
|
||
|
|
#else
|
||
|
|
const int base = 0;
|
||
|
|
#endif
|
||
|
|
const u8 *anchor = ip;
|
||
|
|
const u8 *const iend = ip + isize;
|
||
|
|
const u8 *const mflimit = iend - MFLIMIT;
|
||
|
|
#define MATCHLIMIT (iend - LASTLITERALS)
|
||
|
|
|
||
|
|
u8 *op = (u8 *) dest;
|
||
|
|
u8 *const oend = op + maxoutputsize;
|
||
|
|
int length;
|
||
|
|
const int skipstrength = SKIPSTRENGTH;
|
||
|
|
u32 forwardh;
|
||
|
|
int lastrun;
|
||
|
|
|
||
|
|
/* Init */
|
||
|
|
if (isize < MINLENGTH)
|
||
|
|
goto _last_literals;
|
||
|
|
|
||
|
|
memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
|
||
|
|
|
||
|
|
/* First Byte */
|
||
|
|
hashtable[LZ4_HASH_VALUE(ip)] = ip - base;
|
||
|
|
ip++;
|
||
|
|
forwardh = LZ4_HASH_VALUE(ip);
|
||
|
|
|
||
|
|
/* Main Loop */
|
||
|
|
for (;;) {
|
||
|
|
int findmatchattempts = (1U << skipstrength) + 3;
|
||
|
|
const u8 *forwardip = ip;
|
||
|
|
const u8 *ref;
|
||
|
|
u8 *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 > (u8 *)source) &&
|
||
|
|
unlikely(ip[-1] == ref[-1])) {
|
||
|
|
ip--;
|
||
|
|
ref--;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Encode Literal length */
|
||
|
|
length = (int)(ip - anchor);
|
||
|
|
token = op++;
|
||
|
|
/* check output limit */
|
||
|
|
if (unlikely(op + length + (2 + 1 + LASTLITERALS) +
|
||
|
|
(length >> 8) > oend))
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (length >= (int)RUN_MASK) {
|
||
|
|
int len;
|
||
|
|
*token = (RUN_MASK << ML_BITS);
|
||
|
|
len = length - RUN_MASK;
|
||
|
|
for (; len > 254 ; len -= 255)
|
||
|
|
*op++ = 255;
|
||
|
|
*op++ = (u8)len;
|
||
|
|
} else
|
||
|
|
*token = (length << ML_BITS);
|
||
|
|
|
||
|
|
/* Copy Literals */
|
||
|
|
LZ4_BLINDCOPY(anchor, op, length);
|
||
|
|
_next_match:
|
||
|
|
/* Encode Offset */
|
||
|
|
LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
|
||
|
|
|
||
|
|
/* Start Counting */
|
||
|
|
ip += MINMATCH;
|
||
|
|
/* MinMatch verified */
|
||
|
|
ref += MINMATCH;
|
||
|
|
anchor = ip;
|
||
|
|
while (likely(ip < MATCHLIMIT - (STEPSIZE - 1))) {
|
||
|
|
#if LZ4_ARCH64
|
||
|
|
u64 diff = A64(ref) ^ A64(ip);
|
||
|
|
#else
|
||
|
|
u32 diff = A32(ref) ^ A32(ip);
|
||
|
|
#endif
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
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);
|
||
|
|
/* Check output limit */
|
||
|
|
if (unlikely(op + (1 + LASTLITERALS) + (length >> 8) > oend))
|
||
|
|
return 0;
|
||
|
|
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++ = (u8)length;
|
||
|
|
} else
|
||
|
|
*token += length;
|
||
|
|
|
||
|
|
/* 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 */
|
||
|
|
lastrun = (int)(iend - anchor);
|
||
|
|
if (((char *)op - dest) + lastrun + 1
|
||
|
|
+ ((lastrun + 255 - RUN_MASK) / 255) > (u32)maxoutputsize)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (lastrun >= (int)RUN_MASK) {
|
||
|
|
*op++ = (RUN_MASK << ML_BITS);
|
||
|
|
lastrun -= RUN_MASK;
|
||
|
|
for (; lastrun > 254 ; lastrun -= 255)
|
||
|
|
*op++ = 255;
|
||
|
|
*op++ = (u8)lastrun;
|
||
|
|
} else
|
||
|
|
*op++ = (lastrun << ML_BITS);
|
||
|
|
memcpy(op, anchor, iend - anchor);
|
||
|
|
op += iend - anchor;
|
||
|
|
|
||
|
|
/* End */
|
||
|
|
return (int)(((char *)op) - dest);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int lz4_compress64kctx(void *ctx,
|
||
|
|
const char *source,
|
||
|
|
char *dest,
|
||
|
|
int isize,
|
||
|
|
int maxoutputsize)
|
||
|
|
{
|
||
|
|
u16 *hashtable = (u16 *)ctx;
|
||
|
|
const u8 *ip = (u8 *) source;
|
||
|
|
const u8 *anchor = ip;
|
||
|
|
const u8 *const base = ip;
|
||
|
|
const u8 *const iend = ip + isize;
|
||
|
|
const u8 *const mflimit = iend - MFLIMIT;
|
||
|
|
#define MATCHLIMIT (iend - LASTLITERALS)
|
||
|
|
|
||
|
|
u8 *op = (u8 *) dest;
|
||
|
|
u8 *const oend = op + maxoutputsize;
|
||
|
|
int len, length;
|
||
|
|
const int skipstrength = SKIPSTRENGTH;
|
||
|
|
u32 forwardh;
|
||
|
|
int lastrun;
|
||
|
|
|
||
|
|
/* Init */
|
||
|
|
if (isize < MINLENGTH)
|
||
|
|
goto _last_literals;
|
||
|
|
|
||
|
|
memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
|
||
|
|
|
||
|
|
/* First Byte */
|
||
|
|
ip++;
|
||
|
|
forwardh = LZ4_HASH64K_VALUE(ip);
|
||
|
|
|
||
|
|
/* Main Loop */
|
||
|
|
for (;;) {
|
||
|
|
int findmatchattempts = (1U << skipstrength) + 3;
|
||
|
|
const u8 *forwardip = ip;
|
||
|
|
const u8 *ref;
|
||
|
|
u8 *token;
|
||
|
|
|
||
|
|
/* Find a match */
|
||
|
|
do {
|
||
|
|
u32 h = forwardh;
|
||
|
|
int step = findmatchattempts++ >> skipstrength;
|
||
|
|
ip = forwardip;
|
||
|
|
forwardip = ip + step;
|
||
|
|
|
||
|
|
if (forwardip > mflimit)
|
||
|
|
goto _last_literals;
|
||
|
|
|
||
|
|
forwardh = LZ4_HASH64K_VALUE(forwardip);
|
||
|
|
ref = base + hashtable[h];
|
||
|
|
hashtable[h] = (u16)(ip - base);
|
||
|
|
} while (A32(ref) != A32(ip));
|
||
|
|
|
||
|
|
/* Catch up */
|
||
|
|
while ((ip > anchor) && (ref > (u8 *)source)
|
||
|
|
&& (ip[-1] == ref[-1])) {
|
||
|
|
ip--;
|
||
|
|
ref--;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Encode Literal length */
|
||
|
|
length = (int)(ip - anchor);
|
||
|
|
token = op++;
|
||
|
|
/* Check output limit */
|
||
|
|
if (unlikely(op + length + (2 + 1 + LASTLITERALS)
|
||
|
|
+ (length >> 8) > oend))
|
||
|
|
return 0;
|
||
|
|
if (length >= (int)RUN_MASK) {
|
||
|
|
*token = (RUN_MASK << ML_BITS);
|
||
|
|
len = length - RUN_MASK;
|
||
|
|
for (; len > 254 ; len -= 255)
|
||
|
|
*op++ = 255;
|
||
|
|
*op++ = (u8)len;
|
||
|
|
} else
|
||
|
|
*token = (length << ML_BITS);
|
||
|
|
|
||
|
|
/* Copy Literals */
|
||
|
|
LZ4_BLINDCOPY(anchor, op, length);
|
||
|
|
|
||
|
|
_next_match:
|
||
|
|
/* Encode Offset */
|
||
|
|
LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
|
||
|
|
|
||
|
|
/* Start Counting */
|
||
|
|
ip += MINMATCH;
|
||
|
|
/* MinMatch verified */
|
||
|
|
ref += MINMATCH;
|
||
|
|
anchor = ip;
|
||
|
|
|
||
|
|
while (ip < MATCHLIMIT - (STEPSIZE - 1)) {
|
||
|
|
#if LZ4_ARCH64
|
||
|
|
u64 diff = A64(ref) ^ A64(ip);
|
||
|
|
#else
|
||
|
|
u32 diff = A32(ref) ^ A32(ip);
|
||
|
|
#endif
|
||
|
|
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
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);
|
||
|
|
/* Check output limit */
|
||
|
|
if (unlikely(op + (1 + LASTLITERALS) + (len >> 8) > oend))
|
||
|
|
return 0;
|
||
|
|
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++ = (u8)len;
|
||
|
|
} else
|
||
|
|
*token += len;
|
||
|
|
|
||
|
|
/* Test end of chunk */
|
||
|
|
if (ip > mflimit) {
|
||
|
|
anchor = ip;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Fill table */
|
||
|
|
hashtable[LZ4_HASH64K_VALUE(ip-2)] = (u16)(ip - 2 - base);
|
||
|
|
|
||
|
|
/* Test next position */
|
||
|
|
ref = base + hashtable[LZ4_HASH64K_VALUE(ip)];
|
||
|
|
hashtable[LZ4_HASH64K_VALUE(ip)] = (u16)(ip - base);
|
||
|
|
if (A32(ref) == A32(ip)) {
|
||
|
|
token = op++;
|
||
|
|
*token = 0;
|
||
|
|
goto _next_match;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Prepare next loop */
|
||
|
|
anchor = ip++;
|
||
|
|
forwardh = LZ4_HASH64K_VALUE(ip);
|
||
|
|
}
|
||
|
|
|
||
|
|
_last_literals:
|
||
|
|
/* Encode Last Literals */
|
||
|
|
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++ = (u8)lastrun;
|
||
|
|
} else
|
||
|
|
*op++ = (lastrun << ML_BITS);
|
||
|
|
memcpy(op, anchor, iend - anchor);
|
||
|
|
op += iend - anchor;
|
||
|
|
/* End */
|
||
|
|
return (int)(((char *)op) - dest);
|
||
|
|
}
|
||
|
|
|
||
|
|
int lz4_compress(const unsigned char *src, size_t src_len,
|
||
|
|
unsigned char *dst, size_t *dst_len, void *wrkmem)
|
||
|
|
{
|
||
|
|
int ret = -1;
|
||
|
|
int out_len = 0;
|
||
|
|
|
||
|
|
if (src_len < LZ4_64KLIMIT)
|
||
|
|
out_len = lz4_compress64kctx(wrkmem, src, dst, src_len,
|
||
|
|
lz4_compressbound(src_len));
|
||
|
|
else
|
||
|
|
out_len = lz4_compressctx(wrkmem, src, dst, src_len,
|
||
|
|
lz4_compressbound(src_len));
|
||
|
|
|
||
|
|
if (out_len < 0)
|
||
|
|
goto exit;
|
||
|
|
|
||
|
|
*dst_len = out_len;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
exit:
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(lz4_compress);
|
||
|
|
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
MODULE_DESCRIPTION("LZ4 compressor");
|