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foxbox/tools/ucl/src/ucl_swd.ch
Linus Nielsen Feltzing e2022a26d0 Removed executable flag 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11967 a1c6a512-1295-4272-9138-f99709370657
2007-01-09 23:29:07 +00:00

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/* ucl_swd.c -- sliding window dictionary
This file is part of the UCL data compression library.
Copyright (C) 1996-2002 Markus Franz Xaver Johannes Oberhumer
All Rights Reserved.
The UCL library is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
The UCL library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the UCL library; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Markus F.X.J. Oberhumer
<markus@oberhumer.com>
*/
#if (UCL_UINT_MAX < UCL_0xffffffffL)
# error "UCL_UINT_MAX"
#endif
/***********************************************************************
//
************************************************************************/
#ifndef SWD_N
# define SWD_N N
#endif
#ifndef SWD_F
# define SWD_F F
#endif
#ifndef SWD_THRESHOLD
# define SWD_THRESHOLD THRESHOLD
#endif
/* unsigned type for dictionary access - don't waste memory here */
#if (SWD_N + SWD_F + SWD_F < USHRT_MAX)
typedef unsigned short swd_uint;
# define SWD_UINT_MAX USHRT_MAX
#else
typedef ucl_uint swd_uint;
# define SWD_UINT_MAX UCL_UINT_MAX
#endif
#define SWD_UINT(x) ((swd_uint)(x))
#ifndef SWD_HSIZE
# define SWD_HSIZE 16384
#endif
#ifndef SWD_MAX_CHAIN
# define SWD_MAX_CHAIN 2048
#endif
#if !defined(HEAD3)
#if 1
# define HEAD3(b,p) \
(((0x9f5f*(((((ucl_uint32)b[p]<<5)^b[p+1])<<5)^b[p+2]))>>5) & (SWD_HSIZE-1))
#else
# define HEAD3(b,p) \
(((0x9f5f*(((((ucl_uint32)b[p+2]<<5)^b[p+1])<<5)^b[p]))>>5) & (SWD_HSIZE-1))
#endif
#endif
#if (SWD_THRESHOLD == 1) && !defined(HEAD2)
# if 1 && defined(UCL_UNALIGNED_OK_2)
# define HEAD2(b,p) (* (const ucl_ushortp) &(b[p]))
# else
# define HEAD2(b,p) (b[p] ^ ((unsigned)b[p+1]<<8))
# endif
# define NIL2 SWD_UINT_MAX
#endif
#if defined(__UCL_CHECKER)
/* malloc arrays of the exact size to detect any overrun */
# ifndef SWD_USE_MALLOC
# define SWD_USE_MALLOC
# endif
#endif
typedef struct
{
/* public - "built-in" */
ucl_uint n;
ucl_uint f;
ucl_uint threshold;
/* public - configuration */
ucl_uint max_chain;
ucl_uint nice_length;
ucl_bool use_best_off;
ucl_uint lazy_insert;
/* public - output */
ucl_uint m_len;
ucl_uint m_off;
ucl_uint look;
int b_char;
#if defined(SWD_BEST_OFF)
ucl_uint best_off[ SWD_BEST_OFF ];
#endif
/* semi public */
UCL_COMPRESS_T *c;
ucl_uint m_pos;
#if defined(SWD_BEST_OFF)
ucl_uint best_pos[ SWD_BEST_OFF ];
#endif
/* private */
const ucl_byte *dict;
const ucl_byte *dict_end;
ucl_uint dict_len;
/* private */
ucl_uint ip; /* input pointer (lookahead) */
ucl_uint bp; /* buffer pointer */
ucl_uint rp; /* remove pointer */
ucl_uint b_size;
unsigned char *b_wrap;
ucl_uint node_count;
ucl_uint first_rp;
#if defined(SWD_USE_MALLOC)
unsigned char *b;
swd_uint *head3;
swd_uint *succ3;
swd_uint *best3;
swd_uint *llen3;
#ifdef HEAD2
swd_uint *head2;
#endif
#else
unsigned char b [ SWD_N + SWD_F + SWD_F ];
swd_uint head3 [ SWD_HSIZE ];
swd_uint succ3 [ SWD_N + SWD_F ];
swd_uint best3 [ SWD_N + SWD_F ];
swd_uint llen3 [ SWD_HSIZE ];
#ifdef HEAD2
swd_uint head2 [ UCL_UINT32_C(65536) ];
#endif
#endif
}
ucl_swd_t;
/* Access macro for head3.
* head3[key] may be uninitialized if the list is emtpy,
* but then its value will never be used.
*/
#if defined(__UCL_CHECKER)
# define s_head3(s,key) \
((s->llen3[key] == 0) ? SWD_UINT_MAX : s->head3[key])
#else
# define s_head3(s,key) s->head3[key]
#endif
/***********************************************************************
//
************************************************************************/
static
void swd_initdict(ucl_swd_t *s, const ucl_byte *dict, ucl_uint dict_len)
{
s->dict = s->dict_end = NULL;
s->dict_len = 0;
if (!dict || dict_len <= 0)
return;
if (dict_len > s->n)
{
dict += dict_len - s->n;
dict_len = s->n;
}
s->dict = dict;
s->dict_len = dict_len;
s->dict_end = dict + dict_len;
ucl_memcpy(s->b,dict,dict_len);
s->ip = dict_len;
}
static
void swd_insertdict(ucl_swd_t *s, ucl_uint node, ucl_uint len)
{
ucl_uint key;
s->node_count = s->n - len;
s->first_rp = node;
while (len-- > 0)
{
key = HEAD3(s->b,node);
s->succ3[node] = s_head3(s,key);
s->head3[key] = SWD_UINT(node);
s->best3[node] = SWD_UINT(s->f + 1);
s->llen3[key]++;
assert(s->llen3[key] <= s->n);
#ifdef HEAD2
key = HEAD2(s->b,node);
s->head2[key] = SWD_UINT(node);
#endif
node++;
}
}
/***********************************************************************
//
************************************************************************/
static
int swd_init(ucl_swd_t *s, const ucl_byte *dict, ucl_uint dict_len)
{
ucl_uint i = 0;
int c = 0;
if (s->n == 0)
s->n = SWD_N;
if (s->f == 0)
s->f = SWD_F;
s->threshold = SWD_THRESHOLD;
if (s->n > SWD_N || s->f > SWD_F)
return UCL_E_INVALID_ARGUMENT;
#if defined(SWD_USE_MALLOC)
s->b = (unsigned char *) ucl_alloc(s->n + s->f + s->f, 1);
s->head3 = (swd_uint *) ucl_alloc(SWD_HSIZE, sizeof(*s->head3));
s->succ3 = (swd_uint *) ucl_alloc(s->n + s->f, sizeof(*s->succ3));
s->best3 = (swd_uint *) ucl_alloc(s->n + s->f, sizeof(*s->best3));
s->llen3 = (swd_uint *) ucl_alloc(SWD_HSIZE, sizeof(*s->llen3));
if (!s->b || !s->head3 || !s->succ3 || !s->best3 || !s->llen3)
return UCL_E_OUT_OF_MEMORY;
#ifdef HEAD2
s->head2 = (swd_uint *) ucl_alloc(UCL_UINT32_C(65536), sizeof(*s->head2));
if (!s->head2)
return UCL_E_OUT_OF_MEMORY;
#endif
#endif
/* defaults */
s->max_chain = SWD_MAX_CHAIN;
s->nice_length = s->f;
s->use_best_off = 0;
s->lazy_insert = 0;
s->b_size = s->n + s->f;
if (s->b_size + s->f >= SWD_UINT_MAX)
return UCL_E_ERROR;
s->b_wrap = s->b + s->b_size;
s->node_count = s->n;
ucl_memset(s->llen3, 0, sizeof(s->llen3[0]) * SWD_HSIZE);
#ifdef HEAD2
#if 1
ucl_memset(s->head2, 0xff, sizeof(s->head2[0]) * UCL_UINT32_C(65536));
assert(s->head2[0] == NIL2);
#else
for (i = 0; i < UCL_UINT32_C(65536); i++)
s->head2[i] = NIL2;
#endif
#endif
s->ip = 0;
swd_initdict(s,dict,dict_len);
s->bp = s->ip;
s->first_rp = s->ip;
assert(s->ip + s->f <= s->b_size);
#if 1
s->look = (ucl_uint) (s->c->in_end - s->c->ip);
if (s->look > 0)
{
if (s->look > s->f)
s->look = s->f;
ucl_memcpy(&s->b[s->ip],s->c->ip,s->look);
s->c->ip += s->look;
s->ip += s->look;
}
#else
s->look = 0;
while (s->look < s->f)
{
if ((c = getbyte(*(s->c))) < 0)
break;
s->b[s->ip] = UCL_BYTE(c);
s->ip++;
s->look++;
}
#endif
if (s->ip == s->b_size)
s->ip = 0;
if (s->look >= 2 && s->dict_len > 0)
swd_insertdict(s,0,s->dict_len);
s->rp = s->first_rp;
if (s->rp >= s->node_count)
s->rp -= s->node_count;
else
s->rp += s->b_size - s->node_count;
#if defined(__UCL_CHECKER)
/* initialize memory for the first few HEAD3 (if s->ip is not far
* enough ahead to do this job for us). The value doesn't matter. */
if (s->look < 3)
ucl_memset(&s->b[s->bp+s->look],0,3);
#endif
UCL_UNUSED(i);
UCL_UNUSED(c);
return UCL_E_OK;
}
static
void swd_exit(ucl_swd_t *s)
{
#if defined(SWD_USE_MALLOC)
/* free in reverse order of allocations */
#ifdef HEAD2
ucl_free(s->head2); s->head2 = NULL;
#endif
ucl_free(s->llen3); s->llen3 = NULL;
ucl_free(s->best3); s->best3 = NULL;
ucl_free(s->succ3); s->succ3 = NULL;
ucl_free(s->head3); s->head3 = NULL;
ucl_free(s->b); s->b = NULL;
#else
UCL_UNUSED(s);
#endif
}
#define swd_pos2off(s,pos) \
(s->bp > (pos) ? s->bp - (pos) : s->b_size - ((pos) - s->bp))
/***********************************************************************
//
************************************************************************/
static __inline__
void swd_getbyte(ucl_swd_t *s)
{
int c;
if ((c = getbyte(*(s->c))) < 0)
{
if (s->look > 0)
--s->look;
#if defined(__UCL_CHECKER)
/* initialize memory - value doesn't matter */
s->b[s->ip] = 0;
if (s->ip < s->f)
s->b_wrap[s->ip] = 0;
#endif
}
else
{
s->b[s->ip] = UCL_BYTE(c);
if (s->ip < s->f)
s->b_wrap[s->ip] = UCL_BYTE(c);
}
if (++s->ip == s->b_size)
s->ip = 0;
if (++s->bp == s->b_size)
s->bp = 0;
if (++s->rp == s->b_size)
s->rp = 0;
}
/***********************************************************************
// remove node from lists
************************************************************************/
static __inline__
void swd_remove_node(ucl_swd_t *s, ucl_uint node)
{
if (s->node_count == 0)
{
ucl_uint key;
#ifdef UCL_DEBUG
if (s->first_rp != UCL_UINT_MAX)
{
if (node != s->first_rp)
printf("Remove %5d: %5d %5d %5d %5d %6d %6d\n",
node, s->rp, s->ip, s->bp, s->first_rp,
s->ip - node, s->ip - s->bp);
assert(node == s->first_rp);
s->first_rp = UCL_UINT_MAX;
}
#endif
key = HEAD3(s->b,node);
assert(s->llen3[key] > 0);
--s->llen3[key];
#ifdef HEAD2
key = HEAD2(s->b,node);
assert(s->head2[key] != NIL2);
if ((ucl_uint) s->head2[key] == node)
s->head2[key] = NIL2;
#endif
}
else
--s->node_count;
}
/***********************************************************************
//
************************************************************************/
static
void swd_accept(ucl_swd_t *s, ucl_uint n)
{
assert(n <= s->look);
if (n > 0) do
{
ucl_uint key;
swd_remove_node(s,s->rp);
/* add bp into HEAD3 */
key = HEAD3(s->b,s->bp);
s->succ3[s->bp] = s_head3(s,key);
s->head3[key] = SWD_UINT(s->bp);
s->best3[s->bp] = SWD_UINT(s->f + 1);
s->llen3[key]++;
assert(s->llen3[key] <= s->n);
#ifdef HEAD2
/* add bp into HEAD2 */
key = HEAD2(s->b,s->bp);
s->head2[key] = SWD_UINT(s->bp);
#endif
swd_getbyte(s);
} while (--n > 0);
}
/***********************************************************************
//
************************************************************************/
static
void swd_search(ucl_swd_t *s, ucl_uint node, ucl_uint cnt)
{
#if 0 && defined(__GNUC__) && defined(__i386__)
register const unsigned char *p1 __asm__("%edi");
register const unsigned char *p2 __asm__("%esi");
register const unsigned char *px __asm__("%edx");
#else
const unsigned char *p1;
const unsigned char *p2;
const unsigned char *px;
#endif
ucl_uint m_len = s->m_len;
const unsigned char * b = s->b;
const unsigned char * bp = s->b + s->bp;
const unsigned char * bx = s->b + s->bp + s->look;
unsigned char scan_end1;
assert(s->m_len > 0);
scan_end1 = bp[m_len - 1];
for ( ; cnt-- > 0; node = s->succ3[node])
{
p1 = bp;
p2 = b + node;
px = bx;
assert(m_len < s->look);
if (
#if 1
p2[m_len - 1] == scan_end1 &&
p2[m_len] == p1[m_len] &&
#endif
p2[0] == p1[0] &&
p2[1] == p1[1])
{
ucl_uint i;
assert(ucl_memcmp(bp,&b[node],3) == 0);
#if 0 && defined(UCL_UNALIGNED_OK_4)
p1 += 3; p2 += 3;
while (p1 < px && * (const ucl_uint32p) p1 == * (const ucl_uint32p) p2)
p1 += 4, p2 += 4;
while (p1 < px && *p1 == *p2)
p1 += 1, p2 += 1;
#else
p1 += 2; p2 += 2;
do {} while (++p1 < px && *p1 == *++p2);
#endif
i = p1 - bp;
#ifdef UCL_DEBUG
if (ucl_memcmp(bp,&b[node],i) != 0)
printf("%5ld %5ld %02x%02x %02x%02x\n",
(long)s->bp, (long) node,
bp[0], bp[1], b[node], b[node+1]);
#endif
assert(ucl_memcmp(bp,&b[node],i) == 0);
#if defined(SWD_BEST_OFF)
if (i < SWD_BEST_OFF)
{
if (s->best_pos[i] == 0)
s->best_pos[i] = node + 1;
}
#endif
if (i > m_len)
{
s->m_len = m_len = i;
s->m_pos = node;
if (m_len == s->look)
return;
if (m_len >= s->nice_length)
return;
if (m_len > (ucl_uint) s->best3[node])
return;
scan_end1 = bp[m_len - 1];
}
}
}
}
/***********************************************************************
//
************************************************************************/
#ifdef HEAD2
static
ucl_bool swd_search2(ucl_swd_t *s)
{
ucl_uint key;
assert(s->look >= 2);
assert(s->m_len > 0);
key = s->head2[ HEAD2(s->b,s->bp) ];
if (key == NIL2)
return 0;
#ifdef UCL_DEBUG
if (ucl_memcmp(&s->b[s->bp],&s->b[key],2) != 0)
printf("%5ld %5ld %02x%02x %02x%02x\n", (long)s->bp, (long)key,
s->b[s->bp], s->b[s->bp+1], s->b[key], s->b[key+1]);
#endif
assert(ucl_memcmp(&s->b[s->bp],&s->b[key],2) == 0);
#if defined(SWD_BEST_OFF)
if (s->best_pos[2] == 0)
s->best_pos[2] = key + 1;
#endif
if (s->m_len < 2)
{
s->m_len = 2;
s->m_pos = key;
}
return 1;
}
#endif
/***********************************************************************
//
************************************************************************/
static
void swd_findbest(ucl_swd_t *s)
{
ucl_uint key;
ucl_uint cnt, node;
ucl_uint len;
assert(s->m_len > 0);
/* get current head, add bp into HEAD3 */
key = HEAD3(s->b,s->bp);
node = s->succ3[s->bp] = s_head3(s,key);
cnt = s->llen3[key]++;
assert(s->llen3[key] <= s->n + s->f);
if (cnt > s->max_chain && s->max_chain > 0)
cnt = s->max_chain;
s->head3[key] = SWD_UINT(s->bp);
s->b_char = s->b[s->bp];
len = s->m_len;
if (s->m_len >= s->look)
{
if (s->look == 0)
s->b_char = -1;
s->m_off = 0;
s->best3[s->bp] = SWD_UINT(s->f + 1);
}
else
{
#ifdef HEAD2
if (swd_search2(s))
#endif
if (s->look >= 3)
swd_search(s,node,cnt);
if (s->m_len > len)
s->m_off = swd_pos2off(s,s->m_pos);
s->best3[s->bp] = SWD_UINT(s->m_len);
#if defined(SWD_BEST_OFF)
if (s->use_best_off)
{
int i;
for (i = 2; i < SWD_BEST_OFF; i++)
if (s->best_pos[i] > 0)
s->best_off[i] = swd_pos2off(s,s->best_pos[i]-1);
else
s->best_off[i] = 0;
}
#endif
}
swd_remove_node(s,s->rp);
#ifdef HEAD2
/* add bp into HEAD2 */
key = HEAD2(s->b,s->bp);
s->head2[key] = SWD_UINT(s->bp);
#endif
}
#undef HEAD3
#undef HEAD2
#undef s_head3
/*
vi:ts=4:et
*/
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