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upgrade liblzf to the latest 3.6
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thanks for the pointer, vcelakv
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Travis J Parker committed Nov 23, 2011
1 parent 0e0dd17 commit e6cefc5
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Showing 3 changed files with 111 additions and 54 deletions.
64 changes: 45 additions & 19 deletions lzfP.h
View file
Expand Up @@ -49,7 +49,7 @@
* the difference between 15 and 14 is very small
* for small blocks (and 14 is usually a bit faster).
* For a low-memory/faster configuration, use HLOG == 13;
* For best compression, use 15 or 16 (or more, up to 23).
* For best compression, use 15 or 16 (or more, up to 22).
*/
#ifndef HLOG
# define HLOG 16
Expand Down Expand Up @@ -93,15 +93,15 @@

/*
* Avoid assigning values to errno variable? for some embedding purposes
* (linux kernel for example), this is neccessary. NOTE: this breaks
* the documentation in lzf.h.
* (linux kernel for example), this is necessary. NOTE: this breaks
* the documentation in lzf.h. Avoiding errno has no speed impact.
*/
#ifndef AVOID_ERRNO
# define AVOID_ERRNO 0
#endif

/*
* Wether to pass the LZF_STATE variable as argument, or allocate it
* Whether to pass the LZF_STATE variable as argument, or allocate it
* on the stack. For small-stack environments, define this to 1.
* NOTE: this breaks the prototype in lzf.h.
*/
Expand All @@ -110,27 +110,63 @@
#endif

/*
* Wether to add extra checks for input validity in lzf_decompress
* Whether to add extra checks for input validity in lzf_decompress
* and return EINVAL if the input stream has been corrupted. This
* only shields against overflowing the input buffer and will not
* detect most corrupted streams.
* This check is not normally noticable on modern hardware
* This check is not normally noticeable on modern hardware
* (<1% slowdown), but might slow down older cpus considerably.
*/
#ifndef CHECK_INPUT
# define CHECK_INPUT 1
#endif

/*
* Whether to store pointers or offsets inside the hash table. On
* 64 bit architetcures, pointers take up twice as much space,
* and might also be slower. Default is to autodetect.
*/
/*#define LZF_USER_OFFSETS autodetect */

/*****************************************************************************/
/* nothing should be changed below */

#ifdef __cplusplus
# include <cstring>
# include <climits>
using namespace std;
#else
# include <string.h>
# include <limits.h>
#endif

#ifndef LZF_USE_OFFSETS
# if defined (WIN32)
# define LZF_USE_OFFSETS defined(_M_X64)
# else
# if __cplusplus > 199711L
# include <cstdint>
# else
# include <stdint.h>
# endif
# define LZF_USE_OFFSETS (UINTPTR_MAX > 0xffffffffU)
# endif
#endif

typedef unsigned char u8;

typedef const u8 *LZF_STATE[1 << (HLOG)];
#if LZF_USE_OFFSETS
# define LZF_HSLOT_BIAS ((const u8 *)in_data)
typedef unsigned int LZF_HSLOT;
#else
# define LZF_HSLOT_BIAS 0
typedef const u8 *LZF_HSLOT;
#endif

typedef LZF_HSLOT LZF_STATE[1 << (HLOG)];

#if !STRICT_ALIGN
/* for unaligned accesses we need a 16 bit datatype. */
# include <limits.h>
# if USHRT_MAX == 65535
typedef unsigned short u16;
# elif UINT_MAX == 65535
Expand All @@ -142,17 +178,7 @@ typedef const u8 *LZF_STATE[1 << (HLOG)];
#endif

#if ULTRA_FAST
# if defined(VERY_FAST)
# undef VERY_FAST
# endif
#endif

#if INIT_HTAB
# ifdef __cplusplus
# include <cstring>
# else
# include <string.h>
# endif
# undef VERY_FAST
#endif

#endif
Expand Down
42 changes: 19 additions & 23 deletions lzf_c.c
View file
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
* Copyright (c) 2000-2010 Marc Alexander Lehmann <schmorp@schmorp.de>
*
* Redistribution and use in source and binary forms, with or without modifica-
* tion, are permitted provided that the following conditions are met:
Expand Down Expand Up @@ -40,8 +40,8 @@

/*
* don't play with this unless you benchmark!
* decompression is not dependent on the hash function
* the hashing function might seem strange, just believe me
* the data format is not dependent on the hash function.
* the hash function might seem strange, just believe me,
* it works ;)
*/
#ifndef FRST
Expand Down Expand Up @@ -89,9 +89,9 @@
/*
* compressed format
*
* 000LLLLL <L+1> ; literal
* LLLooooo oooooooo ; backref L
* 111ooooo LLLLLLLL oooooooo ; backref L+7
* 000LLLLL <L+1> ; literal, L+1=1..33 octets
* LLLooooo oooooooo ; backref L+1=1..7 octets, o+1=1..4096 offset
* 111ooooo LLLLLLLL oooooooo ; backref L+8 octets, o+1=1..4096 offset
*
*/

Expand All @@ -106,7 +106,6 @@ lzf_compress (const void *const in_data, unsigned int in_len,
#if !LZF_STATE_ARG
LZF_STATE htab;
#endif
const u8 **hslot;
const u8 *ip = (const u8 *)in_data;
u8 *op = (u8 *)out_data;
const u8 *in_end = ip + in_len;
Expand All @@ -133,35 +132,30 @@ lzf_compress (const void *const in_data, unsigned int in_len,

#if INIT_HTAB
memset (htab, 0, sizeof (htab));
# if 0
for (hslot = htab; hslot < htab + HSIZE; hslot++)
*hslot++ = ip;
# endif
#endif

lit = 0; op++; /* start run */

hval = FRST (ip);
while (ip < in_end - 2)
{
LZF_HSLOT *hslot;

hval = NEXT (hval, ip);
hslot = htab + IDX (hval);
ref = *hslot; *hslot = ip;
ref = *hslot + LZF_HSLOT_BIAS; *hslot = ip - LZF_HSLOT_BIAS;

if (1
#if INIT_HTAB
&& ref < ip /* the next test will actually take care of this, but this is faster */
#endif
&& (off = ip - ref - 1) < MAX_OFF
&& ip + 4 < in_end
&& ref > (u8 *)in_data
#if STRICT_ALIGN
&& ref[0] == ip[0]
&& ref[1] == ip[1]
&& ref[2] == ip[2]
#if STRICT_ALIGN
&& ((ref[1] << 8) | ref[0]) == ((ip[1] << 8) | ip[0])
#else
&& *(u16 *)ref == *(u16 *)ip
&& ref[2] == ip[2]
#endif
)
{
Expand All @@ -170,12 +164,13 @@ lzf_compress (const void *const in_data, unsigned int in_len,
unsigned int maxlen = in_end - ip - len;
maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;

if (expect_false (op + 3 + 1 >= out_end)) /* first a faster conservative test */
if (op - !lit + 3 + 1 >= out_end) /* second the exact but rare test */
return 0;

op [- lit - 1] = lit - 1; /* stop run */
op -= !lit; /* undo run if length is zero */

if (expect_false (op + 3 + 1 >= out_end))
return 0;

for (;;)
{
if (expect_true (maxlen > 16))
Expand Down Expand Up @@ -222,6 +217,7 @@ lzf_compress (const void *const in_data, unsigned int in_len,
}

*op++ = off;

lit = 0; op++; /* start run */

ip += len + 1;
Expand All @@ -237,12 +233,12 @@ lzf_compress (const void *const in_data, unsigned int in_len,
hval = FRST (ip);

hval = NEXT (hval, ip);
htab[IDX (hval)] = ip;
htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
ip++;

# if VERY_FAST && !ULTRA_FAST
hval = NEXT (hval, ip);
htab[IDX (hval)] = ip;
htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
ip++;
# endif
#else
Expand All @@ -251,7 +247,7 @@ lzf_compress (const void *const in_data, unsigned int in_len,
do
{
hval = NEXT (hval, ip);
htab[IDX (hval)] = ip;
htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
ip++;
}
while (len--);
Expand Down
59 changes: 47 additions & 12 deletions lzf_d.c
View file
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de>
* Copyright (c) 2000-2010 Marc Alexander Lehmann <schmorp@schmorp.de>
*
* Redistribution and use in source and binary forms, with or without modifica-
* tion, are permitted provided that the following conditions are met:
Expand Down Expand Up @@ -43,14 +43,14 @@
# define SET_ERRNO(n) errno = (n)
#endif

/*
#if USE_REP_MOVSB /* small win on amd, big loss on intel */
#if (__i386 || __amd64) && __GNUC__ >= 3
# define lzf_movsb(dst, src, len) \
asm ("rep movsb" \
: "=D" (dst), "=S" (src), "=c" (len) \
: "0" (dst), "1" (src), "2" (len));
#endif
*/
#endif

unsigned int
lzf_decompress (const void *const in_data, unsigned int in_len,
Expand Down Expand Up @@ -86,9 +86,17 @@ lzf_decompress (const void *const in_data, unsigned int in_len,
#ifdef lzf_movsb
lzf_movsb (op, ip, ctrl);
#else
do
*op++ = *ip++;
while (--ctrl);
switch (ctrl)
{
case 32: *op++ = *ip++; case 31: *op++ = *ip++; case 30: *op++ = *ip++; case 29: *op++ = *ip++;
case 28: *op++ = *ip++; case 27: *op++ = *ip++; case 26: *op++ = *ip++; case 25: *op++ = *ip++;
case 24: *op++ = *ip++; case 23: *op++ = *ip++; case 22: *op++ = *ip++; case 21: *op++ = *ip++;
case 20: *op++ = *ip++; case 19: *op++ = *ip++; case 18: *op++ = *ip++; case 17: *op++ = *ip++;
case 16: *op++ = *ip++; case 15: *op++ = *ip++; case 14: *op++ = *ip++; case 13: *op++ = *ip++;
case 12: *op++ = *ip++; case 11: *op++ = *ip++; case 10: *op++ = *ip++; case 9: *op++ = *ip++;
case 8: *op++ = *ip++; case 7: *op++ = *ip++; case 6: *op++ = *ip++; case 5: *op++ = *ip++;
case 4: *op++ = *ip++; case 3: *op++ = *ip++; case 2: *op++ = *ip++; case 1: *op++ = *ip++;
}
#endif
}
else /* back reference */
Expand Down Expand Up @@ -134,12 +142,39 @@ lzf_decompress (const void *const in_data, unsigned int in_len,
len += 2;
lzf_movsb (op, ref, len);
#else
*op++ = *ref++;
*op++ = *ref++;

do
*op++ = *ref++;
while (--len);
switch (len)
{
default:
len += 2;

if (op >= ref + len)
{
/* disjunct areas */
memcpy (op, ref, len);
op += len;
}
else
{
/* overlapping, use octte by octte copying */
do
*op++ = *ref++;
while (--len);
}

break;

case 9: *op++ = *ref++;
case 8: *op++ = *ref++;
case 7: *op++ = *ref++;
case 6: *op++ = *ref++;
case 5: *op++ = *ref++;
case 4: *op++ = *ref++;
case 3: *op++ = *ref++;
case 2: *op++ = *ref++;
case 1: *op++ = *ref++;
case 0: *op++ = *ref++; /* two octets more */
*op++ = *ref++;
}
#endif
}
}
Expand Down

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