diff options
author | Arne Schwabe <arne@rfc2549.org> | 2012-04-16 19:21:14 +0200 |
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committer | Arne Schwabe <arne@rfc2549.org> | 2012-04-16 19:21:14 +0200 |
commit | 3e4d8f433239c40311037616b1b8833a06651ae0 (patch) | |
tree | 98ab7fce0d011d34677b0beb762d389cb5c39199 /lzo/src/lzo_swd.ch |
Initial import
Diffstat (limited to 'lzo/src/lzo_swd.ch')
-rw-r--r-- | lzo/src/lzo_swd.ch | 707 |
1 files changed, 707 insertions, 0 deletions
diff --git a/lzo/src/lzo_swd.ch b/lzo/src/lzo_swd.ch new file mode 100644 index 00000000..aa4b17c0 --- /dev/null +++ b/lzo/src/lzo_swd.ch @@ -0,0 +1,707 @@ +/* lzo_swd.ch -- sliding window dictionary + + This file is part of the LZO real-time data compression library. + + Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer + Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer + All Rights Reserved. + + The LZO 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 LZO 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 LZO library; see the file COPYING. + If not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + + Markus F.X.J. Oberhumer + <markus@oberhumer.com> + http://www.oberhumer.com/opensource/lzo/ + */ + + +#if (LZO_UINT_MAX < LZO_0xffffffffL) +# error "LZO_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 (0UL + SWD_N + SWD_F + SWD_F < 0UL + USHRT_MAX) + typedef unsigned short swd_uint; +# define SWD_UINT_MAX USHRT_MAX +#elif (0UL + SWD_N + SWD_F + SWD_F < 0UL + UINT_MAX) + typedef unsigned swd_uint; +# define SWD_UINT_MAX UINT_MAX +#else + typedef lzo_uint swd_uint; +# define SWD_UINT_MAX LZO_UINT_MAX +#endif +#define swd_uintp swd_uint __LZO_MMODEL * +#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) \ + ((DMUL(0x9f5f,(((((lzo_xint)b[p]<<5)^b[p+1])<<5)^b[p+2]))>>5) & (SWD_HSIZE-1)) +#else +# define HEAD3(b,p) \ + ((DMUL(0x9f5f,(((((lzo_xint)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(LZO_UNALIGNED_OK_2) +# define HEAD2(b,p) (* (lzo_ushortp) &(b[p])) +# else +# define HEAD2(b,p) (b[p] ^ ((unsigned)b[p+1]<<8)) +# endif +# define NIL2 SWD_UINT_MAX +#endif + + +typedef struct +{ +/* public - "built-in" */ + lzo_uint n; + lzo_uint f; + lzo_uint threshold; + +/* public - configuration */ + lzo_uint max_chain; + lzo_uint nice_length; + lzo_bool use_best_off; + lzo_uint lazy_insert; + +/* public - output */ + lzo_uint m_len; + lzo_uint m_off; + lzo_uint look; + int b_char; +#if defined(SWD_BEST_OFF) + lzo_uint best_off[ SWD_BEST_OFF ]; +#endif + +/* semi public */ + LZO_COMPRESS_T *c; + lzo_uint m_pos; +#if defined(SWD_BEST_OFF) + lzo_uint best_pos[ SWD_BEST_OFF ]; +#endif + +/* private */ + const lzo_bytep dict; + const lzo_bytep dict_end; + lzo_uint dict_len; + +/* private */ + lzo_uint ip; /* input pointer (lookahead) */ + lzo_uint bp; /* buffer pointer */ + lzo_uint rp; /* remove pointer */ + lzo_uint b_size; + + lzo_bytep b_wrap; + + lzo_uint node_count; + lzo_uint first_rp; + +#if defined(__LZO_MMODEL_HUGE) +# define A(type, n) ((((n) * sizeof(type)) + 3UL) &~ 3UL) + +# define O_b(s) (0L) +# define O_head3(s) (O_b(s) + A(char, 0UL + SWD_N + SWD_F + SWD_F)) +# define O_succ3(s) (O_head3(s) + A(swd_uint, 0UL + SWD_HSIZE)) +# define O_best3(s) (O_succ3(s) + A(swd_uint, 0UL + SWD_N + SWD_F)) +# define O_llen3(s) (O_best3(s) + A(swd_uint, 0UL + SWD_N + SWD_F)) +# ifdef HEAD2 +# define O_head2(s) (O_llen3(s) + A(swd_uint, 0UL + SWD_HSIZE)) +# define O_END(s) (O_head2(s) + A(swd_uint, 0UL + 65536L)) +# else +# define O_END(s) (O_llen3(s) + A(swd_uint, 0UL + SWD_HSIZE)) +# endif + +# define S_DEF(s,type,off) ((type) ((lzo_bytep)s + 0L + sizeof(*s) + off)) +# define s_b(s) S_DEF(s, lzo_bytep, O_b(s)) +# define s_head3(s) S_DEF(s, swd_uintp, O_head3(s)) +# define s_succ3(s) S_DEF(s, swd_uintp, O_succ3(s)) +# define s_best3(s) S_DEF(s, swd_uintp, O_best3(s)) +# define s_llen3(s) S_DEF(s, swd_uintp, O_llen3(s)) +# ifdef HEAD2 +# define s_head2(s) S_DEF(s, swd_uintp, O_head2(s)) +# endif + +#elif defined(__LZO_CHECKER) + /* malloc arrays of the exact size to detect any overrun */ + 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 [ 65536L ]; +# endif +#endif +} +lzo_swd_t; +#define lzo_swd_p lzo_swd_t __LZO_MMODEL * + + +#if defined(__LZO_MMODEL_HUGE) +#define SIZEOF_LZO_SWD_T O_END(0) +#else +#define s_b(s) s->b +#define s_head3(s) s->head3 +#define s_succ3(s) s->succ3 +#define s_best3(s) s->best3 +#define s_llen3(s) s->llen3 +#ifdef HEAD2 +#define s_head2(s) s->head2 +#endif +#define SIZEOF_LZO_SWD_T (sizeof(lzo_swd_t)) +#endif + + +/* Access macro for head3. + * head3[key] may be uninitialized, but then its value will never be used. + */ +#if defined(__LZO_CHECKER) +# define s_get_head3(s,key) \ + ((s->llen3[key] == 0) ? SWD_UINT_MAX : s_head3(s)[key]) +#else +# define s_get_head3(s,key) s_head3(s)[key] +#endif + + +/*********************************************************************** +// +************************************************************************/ + +static +void swd_initdict(lzo_swd_p s, const lzo_bytep dict, lzo_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; + lzo_memcpy(s_b(s),dict,dict_len); + s->ip = dict_len; +} + + +static +void swd_insertdict(lzo_swd_p s, lzo_uint node, lzo_uint len) +{ + lzo_uint key; + + s->node_count = s->n - len; + s->first_rp = node; + + while (len-- > 0) + { + key = HEAD3(s_b(s),node); + s_succ3(s)[node] = s_get_head3(s,key); + s_head3(s)[key] = SWD_UINT(node); + s_best3(s)[node] = SWD_UINT(s->f + 1); + s_llen3(s)[key]++; + assert(s_llen3(s)[key] <= SWD_N); + +#ifdef HEAD2 + key = HEAD2(s_b(s),node); + s_head2(s)[key] = SWD_UINT(node); +#endif + + node++; + } +} + + +/*********************************************************************** +// +************************************************************************/ + +static +int swd_init(lzo_swd_p s, const lzo_bytep dict, lzo_uint dict_len) +{ + lzo_uint i = 0; + int c = 0; + +#if defined(__LZO_CHECKER) + s->b = malloc(SWD_N + SWD_F + SWD_F); + s->head3 = malloc(sizeof(swd_uint) * SWD_HSIZE); + s->succ3 = malloc(sizeof(swd_uint) * (SWD_N + SWD_F)); + s->best3 = malloc(sizeof(swd_uint) * (SWD_N + SWD_F)); + s->llen3 = malloc(sizeof(swd_uint) * SWD_HSIZE); +#ifdef HEAD2 + s->head2 = malloc(sizeof(swd_uint) * 65536L); +#endif +#endif + + s->n = SWD_N; + s->f = SWD_F; + s->threshold = SWD_THRESHOLD; + + /* defaults */ + s->max_chain = SWD_MAX_CHAIN; + s->nice_length = SWD_F; + s->use_best_off = 0; + s->lazy_insert = 0; + + s->b_size = s->n + s->f; +#if 0 + if (2 * s->f >= s->n || s->b_size + s->f >= SWD_UINT_MAX) + return LZO_E_ERROR; +#else + LZO_COMPILE_TIME_ASSERT(!(0ul + 2 * SWD_F >= SWD_N)) + LZO_COMPILE_TIME_ASSERT(!(0ul + SWD_N + SWD_F + SWD_F >= SWD_UINT_MAX)) +#endif + s->b_wrap = s_b(s) + s->b_size; + s->node_count = s->n; + + lzo_memset(s_llen3(s), 0, sizeof(s_llen3(s)[0]) * (lzo_uint)SWD_HSIZE); +#ifdef HEAD2 +#if 1 + lzo_memset(s_head2(s), 0xff, sizeof(s_head2(s)[0]) * 65536L); + assert(s_head2(s)[0] == NIL2); +#else + for (i = 0; i < 65536L; i++) + s_head2(s)[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 = (lzo_uint) (s->c->in_end - s->c->ip); + if (s->look > 0) + { + if (s->look > s->f) + s->look = s->f; + lzo_memcpy(&s_b(s)[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)[s->ip] = LZO_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(__LZO_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) + lzo_memset(&s_b(s)[s->bp+s->look],0,3); +#endif + + LZO_UNUSED(i); + LZO_UNUSED(c); + return LZO_E_OK; +} + + +static +void swd_exit(lzo_swd_p s) +{ +#if defined(__LZO_CHECKER) + /* free in reverse order of allocations */ +#ifdef HEAD2 + free(s->head2); s->head2 = NULL; +#endif + free(s->llen3); s->llen3 = NULL; + free(s->best3); s->best3 = NULL; + free(s->succ3); s->succ3 = NULL; + free(s->head3); s->head3 = NULL; + free(s->b); s->b = NULL; +#else + LZO_UNUSED(s); +#endif +} + + +#define swd_pos2off(s,pos) \ + (s->bp > (pos) ? s->bp - (pos) : s->b_size - ((pos) - s->bp)) + + +/*********************************************************************** +// +************************************************************************/ + +static __lzo_inline +void swd_getbyte(lzo_swd_p s) +{ + int c; + + if ((c = getbyte(*(s->c))) < 0) + { + if (s->look > 0) + --s->look; +#if defined(__LZO_CHECKER) + /* initialize memory - value doesn't matter */ + s_b(s)[s->ip] = 0; + if (s->ip < s->f) + s->b_wrap[s->ip] = 0; +#endif + } + else + { + s_b(s)[s->ip] = LZO_BYTE(c); + if (s->ip < s->f) + s->b_wrap[s->ip] = LZO_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 __lzo_inline +void swd_remove_node(lzo_swd_p s, lzo_uint node) +{ + if (s->node_count == 0) + { + lzo_uint key; + +#ifdef LZO_DEBUG + if (s->first_rp != LZO_UINT_MAX) + { + if (node != s->first_rp) + printf("Remove %5u: %5u %5u %5u %5u %6u %6u\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 = LZO_UINT_MAX; + } +#endif + + key = HEAD3(s_b(s),node); + assert(s_llen3(s)[key] > 0); + --s_llen3(s)[key]; + +#ifdef HEAD2 + key = HEAD2(s_b(s),node); + assert(s_head2(s)[key] != NIL2); + if ((lzo_uint) s_head2(s)[key] == node) + s_head2(s)[key] = NIL2; +#endif + } + else + --s->node_count; +} + + +/*********************************************************************** +// +************************************************************************/ + +static +void swd_accept(lzo_swd_p s, lzo_uint n) +{ + assert(n <= s->look); + + while (n--) + { + lzo_uint key; + + swd_remove_node(s,s->rp); + + /* add bp into HEAD3 */ + key = HEAD3(s_b(s),s->bp); + s_succ3(s)[s->bp] = s_get_head3(s,key); + s_head3(s)[key] = SWD_UINT(s->bp); + s_best3(s)[s->bp] = SWD_UINT(s->f + 1); + s_llen3(s)[key]++; + assert(s_llen3(s)[key] <= SWD_N); + +#ifdef HEAD2 + /* add bp into HEAD2 */ + key = HEAD2(s_b(s),s->bp); + s_head2(s)[key] = SWD_UINT(s->bp); +#endif + + swd_getbyte(s); + } +} + + +/*********************************************************************** +// +************************************************************************/ + +static +void swd_search(lzo_swd_p s, lzo_uint node, lzo_uint cnt) +{ + const lzo_bytep p1; + const lzo_bytep p2; + const lzo_bytep px; + lzo_uint m_len = s->m_len; + const lzo_bytep b = s_b(s); + const lzo_bytep bp = s_b(s) + s->bp; + const lzo_bytep bx = s_b(s) + 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(s)[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]) + { + lzo_uint i; + assert(lzo_memcmp(bp,&b[node],3) == 0); + +#if 0 && defined(LZO_UNALIGNED_OK_4) + p1 += 3; p2 += 3; + while (p1 < px && * (const lzo_uint32p) p1 == * (const lzo_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 = pd(p1, bp); + +#ifdef LZO_DEBUG + if (lzo_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(lzo_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 > (lzo_uint) s_best3(s)[node]) + return; + scan_end1 = bp[m_len - 1]; + } + } + } +} + + +/*********************************************************************** +// +************************************************************************/ + +#ifdef HEAD2 + +static +lzo_bool swd_search2(lzo_swd_p s) +{ + lzo_uint key; + + assert(s->look >= 2); + assert(s->m_len > 0); + + key = s_head2(s)[ HEAD2(s_b(s),s->bp) ]; + if (key == NIL2) + return 0; +#ifdef LZO_DEBUG + if (lzo_memcmp(&s_b(s)[s->bp],&s_b(s)[key],2) != 0) + printf("%5ld %5ld %02x%02x %02x%02x\n", (long)s->bp, (long)key, + s_b(s)[s->bp], s_b(s)[s->bp+1], s_b(s)[key], s_b(s)[key+1]); +#endif + assert(lzo_memcmp(&s_b(s)[s->bp],&s_b(s)[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(lzo_swd_p s) +{ + lzo_uint key; + lzo_uint cnt, node; + lzo_uint len; + + assert(s->m_len > 0); + + /* get current head, add bp into HEAD3 */ + key = HEAD3(s_b(s),s->bp); + node = s_succ3(s)[s->bp] = s_get_head3(s,key); + cnt = s_llen3(s)[key]++; + assert(s_llen3(s)[key] <= SWD_N + SWD_F); + if (cnt > s->max_chain && s->max_chain > 0) + cnt = s->max_chain; + s_head3(s)[key] = SWD_UINT(s->bp); + + s->b_char = s_b(s)[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)[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)[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),s->bp); + s_head2(s)[key] = SWD_UINT(s->bp); +#endif +} + + +#undef HEAD3 +#undef HEAD2 +#undef s_get_head3 + + +/* +vi:ts=4:et +*/ + |