/* $OpenLDAP: pkg/ldap/libraries/liblunicode/utbm/utbm.c,v 1.5.2.3 2007/01/02 21:43:52 kurt Exp $ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 1998-2007 The OpenLDAP Foundation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
/* Copyright 1997, 1998, 1999 Computing Research Labs,
* New Mexico State University
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COMPUTING RESEARCH LAB OR NEW MEXICO STATE UNIVERSITY BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
* OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
* THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/* $Id: utbm.c,v 1.1 1999/09/21 15:45:17 mleisher Exp $ */
/*
* Assumptions:
* 1. Case conversions of UTF-16 characters must also be UTF-16 characters.
* 2. Case conversions are all one-to-one.
* 3. Text and pattern have already been normalized in some fashion.
*/
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "utbm.h"
/*
* Single pattern character.
*/
typedef struct {
ucs4_t lc;
ucs4_t uc;
ucs4_t tc;
} _utbm_char_t;
typedef struct {
_utbm_char_t *ch;
unsigned long skip;
} _utbm_skip_t;
typedef struct _utbm_pattern_t {
unsigned long flags;
_utbm_char_t *pat;
unsigned long pat_used;
unsigned long pat_size;
unsigned long patlen;
_utbm_skip_t *skip;
unsigned long skip_used;
unsigned long skip_size;
unsigned long md4;
} _utbm_pattern_t;
/*************************************************************************
*
* Support functions.
*
*************************************************************************/
/*
* Routine to look up the skip value for a character.
*/
static unsigned long
_utbm_skip(utbm_pattern_t p, ucs2_t *start, ucs2_t *end)
{
unsigned long i;
ucs4_t c1, c2;
_utbm_skip_t *sp;
if (start >= end)
return 0;
c1 = *start;
c2 = (start + 1 < end) ? *(start + 1) : ~0;
if (0xd800 <= c1 && c1 <= 0xdbff && 0xdc00 <= c2 && c2 <= 0xdfff)
c1 = 0x10000 + (((c1 & 0x03ff) << 10) | (c2 & 0x03ff));
for (i = 0, sp = p->skip; i < p->skip_used; i++, sp++) {
if (!((c1 ^ sp->ch->uc) & (c1 ^ sp->ch->lc) & (c1 ^ sp->ch->tc))) {
return ((unsigned long) (end - start) < sp->skip) ?
end - start : sp->skip;
}
}
return p->patlen;
}
static int
_utbm_match(utbm_pattern_t pat, ucs2_t *text, ucs2_t *start, ucs2_t *end,
unsigned long *match_start, unsigned long *match_end)
{
int check_space;
ucs4_t c1, c2;
unsigned long count;
_utbm_char_t *cp;
/*
* Set the potential match endpoint first.
*/
*match_end = (start - text) + 1;
c1 = *start;
c2 = (start + 1 < end) ? *(start + 1) : ~0;
if (0xd800 <= c1 && c1 <= 0xdbff && 0xdc00 <= c2 && c2 <= 0xdfff) {
c1 = 0x10000 + (((c1 & 0x03ff) << 10) | (c2 & 0x03ff));
/*
* Adjust the match end point to occur after the UTF-16 character.
*/
*match_end = *match_end + 1;
}
if (pat->pat_used == 1) {
*match_start = start - text;
return 1;
}
/*
* Compare backward.
*/
cp = pat->pat + (pat->pat_used - 1);
for (count = pat->patlen; start > text && count > 0;) {
/*
* Ignore non-spacing characters if indicated.
*/
if (pat->flags & UTBM_IGNORE_NONSPACING) {
while (start > text && _utbm_nonspacing(c1)) {
c2 = *--start;
c1 = (start - 1 > text) ? *(start - 1) : ~0;
if (0xdc00 <= c2 && c2 <= 0xdfff &&
0xd800 <= c1 && c1 <= 0xdbff) {
c1 = 0x10000 + (((c1 & 0x03ff) << 10) | (c2 & 0x03ff));
start--;
} else
c1 = c2;
}
}
/*
* Handle space compression if indicated.
*/
if (pat->flags & UTBM_SPACE_COMPRESS) {
check_space = 0;
while (start > text &&
(_utbm_isspace(c1, 1) || _utbm_iscntrl(c1))) {
check_space = _utbm_isspace(c1, 1);
c2 = *--start;
c1 = (start - 1 > text) ? *(start - 1) : ~0;
if (0xdc00 <= c2 && c2 <= 0xdfff &&
0xd800 <= c1 && c1 <= 0xdbff) {
c1 = 0x10000 + (((c1 & 0x03ff) << 10) | (c2 & 0x03ff));
start--;
} else
c1 = c2;
}
/*
* Handle things if space compression was indicated and one or
* more member characters were found.
*/
if (check_space) {
if (cp->uc != ' ')
return 0;
cp--;
count--;
}
}
/*
* Handle the normal comparison cases.
*/
if (count > 0 && ((c1 ^ cp->uc) & (c1 ^ cp->lc) & (c1 ^ cp->tc)))
return 0;
count -= (c1 >= 0x10000) ? 2 : 1;
if (count > 0) {
cp--;
/*
* Get the next preceding character.
*/
if (start > text) {
c2 = *--start;
c1 = (start - 1 > text) ? *(start - 1) : ~0;
if (0xdc00 <= c2 && c2 <= 0xdfff &&
0xd800 <= c1 && c1 <= 0xdbff) {
c1 = 0x10000 + (((c1 & 0x03ff) << 10) | (c2 & 0x03ff));
start--;
} else
c1 = c2;
}
}
}
/*
* Set the match start position.
*/
*match_start = start - text;
return 1;
}
/*************************************************************************
*
* API.
*
*************************************************************************/
utbm_pattern_t
utbm_create_pattern(void)
{
utbm_pattern_t p;
p = (utbm_pattern_t) malloc(sizeof(_utbm_pattern_t));
(void) memset((char *) p, '\0', sizeof(_utbm_pattern_t));
return p;
}
void
utbm_free_pattern(utbm_pattern_t pattern)
{
if (pattern == 0)
return;
if (pattern->pat_size > 0)
free((char *) pattern->pat);
if (pattern->skip_size > 0)
free((char *) pattern->skip);
free((char *) pattern);
}
void
utbm_compile(ucs2_t *pat, unsigned long patlen, unsigned long flags,
utbm_pattern_t p)
{
int have_space;
unsigned long i, j, k, slen;
_utbm_char_t *cp;
_utbm_skip_t *sp;
ucs4_t c1, c2, sentinel;
if (p == 0 || pat == 0 || *pat == 0 || patlen == 0)
return;
/*
* Reset the pattern buffer.
*/
p->patlen = p->pat_used = p->skip_used = 0;
/*
* Set the flags.
*/
p->flags = flags;
/*
* Initialize the extra skip flag.
*/
p->md4 = 1;
/*
* Allocate more storage if necessary.
*/
if (patlen > p->pat_size) {
if (p->pat_size == 0) {
p->pat = (_utbm_char_t *) malloc(sizeof(_utbm_char_t) * patlen);
p->skip = (_utbm_skip_t *) malloc(sizeof(_utbm_skip_t) * patlen);
} else {
p->pat = (_utbm_char_t *)
realloc((char *) p->pat, sizeof(_utbm_char_t) * patlen);
p->skip = (_utbm_skip_t *)
realloc((char *) p->skip, sizeof(_utbm_skip_t) * patlen);
}
p->pat_size = p->skip_size = patlen;
}
/*
* Preprocess the pattern to remove controls (if specified) and determine
* case.
*/
for (have_space = 0, cp = p->pat, i = 0; i < patlen; i++) {
c1 = pat[i];
c2 = (i + 1 < patlen) ? pat[i + 1] : ~0;
if (0xd800 <= c1 && c1 <= 0xdbff && 0xdc00 <= c2 && c2 <= 0xdfff)
c1 = 0x10000 + (((c1 & 0x03ff) << 10) | (c2 & 0x03ff));
/*
* Make sure the `have_space' flag is turned off if the character
* is not an appropriate one.
*/
if (!_utbm_isspace(c1, flags & UTBM_SPACE_COMPRESS))
have_space = 0;
/*
* If non-spacing characters should be ignored, do it here.
*/
if ((flags & UTBM_IGNORE_NONSPACING) && _utbm_nonspacing(c1))
continue;
/*
* Check if spaces and controls need to be compressed.
*/
if (flags & UTBM_SPACE_COMPRESS) {
if (_utbm_isspace(c1, 1)) {
if (!have_space) {
/*
* Add a space and set the flag.
*/
cp->uc = cp->lc = cp->tc = ' ';
cp++;
/*
* Increase the real pattern length.
*/
p->patlen++;
sentinel = ' ';
have_space = 1;
}
continue;
}
/*
* Ignore all control characters.
*/
if (_utbm_iscntrl(c1))
continue;
}
/*
* Add the character.
*/
if (flags & UTBM_CASEFOLD) {
cp->uc = _utbm_toupper(c1);
cp->lc = _utbm_tolower(c1);
cp->tc = _utbm_totitle(c1);
} else
cp->uc = cp->lc = cp->tc = c1;
/*
* Set the sentinel character.
*/
sentinel = cp->uc;
/*
* Move to the next character.
*/
cp++;
/*
* Increase the real pattern length appropriately.
*/
p->patlen += (c1 >= 0x10000) ? 2 : 1;
/*
* Increment the loop index for UTF-16 characters.
*/
i += (c1 >= 0x10000) ? 1 : 0;
}
/*
* Set the number of characters actually used.
*/
p->pat_used = cp - p->pat;
/*
* Go through and construct the skip array and determine the actual length
* of the pattern in UCS2 terms.
*/
slen = p->patlen - 1;
cp = p->pat;
for (i = k = 0; i < p->pat_used; i++, cp++) {
/*
* Locate the character in the skip array.
*/
for (sp = p->skip, j = 0;
j < p->skip_used && sp->ch->uc != cp->uc; j++, sp++) ;
/*
* If the character is not found, set the new skip element and
* increase the number of skip elements.
*/
if (j == p->skip_used) {
sp->ch = cp;
p->skip_used++;
}
/*
* Set the updated skip value. If the character is UTF-16 and is
* not the last one in the pattern, add one to its skip value.
*/
sp->skip = slen - k;
if (cp->uc >= 0x10000 && k + 2 < slen)
sp->skip++;
/*
* Set the new extra skip for the sentinel character.
*/
if (((cp->uc >= 0x10000 && k + 2 <= slen) || k + 1 <= slen) &&
cp->uc == sentinel)
p->md4 = slen - k;
/*
* Increase the actual index.
*/
k += (cp->uc >= 0x10000) ? 2 : 1;
}
}
int
utbm_exec(utbm_pattern_t pat, ucs2_t *text, unsigned long textlen,
unsigned long *match_start, unsigned long *match_end)
{
unsigned long k;
ucs2_t *start, *end;
if (pat == 0 || pat->pat_used == 0 || text == 0 || textlen == 0 ||
textlen < pat->patlen)
return 0;
start = text + pat->patlen;
end = text + textlen;
/*
* Adjust the start point if it points to a low surrogate.
*/
if (0xdc00 <= *start && *start <= 0xdfff &&
0xd800 <= *(start - 1) && *(start - 1) <= 0xdbff)
start--;
while (start < end) {
while ((k = _utbm_skip(pat, start, end))) {
start += k;
if (start < end && 0xdc00 <= *start && *start <= 0xdfff &&
0xd800 <= *(start - 1) && *(start - 1) <= 0xdbff)
start--;
}
if (start < end &&
_utbm_match(pat, text, start, end, match_start, match_end))
return 1;
start += pat->md4;
if (start < end && 0xdc00 <= *start && *start <= 0xdfff &&
0xd800 <= *(start - 1) && *(start - 1) <= 0xdbff)
start--;
}
return 0;
}
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