/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
* Copyright (C) 2000 Helix Code, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public License
* as published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with the Gnome Library; see the file COPYING.LIB. If not,
* write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/* words.c: low-level indexing ops */
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <unicode.h>
#include "ibex_internal.h"
static signed char utf8_trans[] = {
'A', 'A', 'A', 'A', 'A', 'A', -1, 'C', 'E', 'E', 'E', 'E', 'I', 'I',
'I', 'I', -2, 'N', 'O', 'O', 'O', 'O', 'O', '*', 'O', 'U', 'U', 'U',
'U', 'Y', -3, -4, 'a', 'a', 'a', 'a', 'a', 'a', -5, 'c', 'e', 'e',
'e', 'e', 'i', 'i', 'i', 'i', -6, 'n', 'o', 'o', 'o', 'o', 'o', '/',
'o', 'u', 'u', 'u', 'u', 'y', -7, 'y', 'A', 'a', 'A', 'a', 'A', 'a',
'C', 'c', 'C', 'c', 'C', 'c', 'C', 'c', 'D', 'd', 'D', 'd', 'E', 'e',
'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'G', 'g', 'G', 'g', 'G', 'g',
'G', 'g', 'H', 'h', 'H', 'h', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i',
'I', 'i', -8, -9, 'J', 'j', 'K', 'k', 'k', 'L', 'l', 'L', 'l', 'L',
'l', 'L', 'l', 'L', 'l', 'N', 'n', 'N', 'n', 'N', 'n', 'n', -10, -11,
'O', 'o', 'O', 'o', 'O', 'o', -12, -13, 'R', 'r', 'R', 'r', 'R', 'r',
'S', 'r', 'S', 's', 'S', 's', 'S', 's', 'T', 't', 'T', 't', 'T', 't',
'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'W', 'w',
'Y', 'y', 'Y', 'Z', 'z', 'Z', 'z', 'Z', 'z', 's'
};
static char *utf8_long_trans[] = {
"AE", "TH", "TH", "ss", "ae", "th", "th", "IJ", "ij",
"NG", "ng", "OE", "oe"
};
/* This is a bit weird. It takes pointers to the start and end (actually
* just past the end) of a UTF-8-encoded word, and a buffer at least 1
* byte longer than the length of the word. It copies the word into the
* buffer in all lowercase without accents, and splits up ligatures.
* (Since any ligature would be a multi-byte character in UTF-8, splitting
* them into two US-ASCII characters won't overrun the buffer.)
*
* It is not safe to call this routine with bad UTF-8.
*/
static void
normalize_word (char *start, char *end, char *buf)
{
unsigned char *s, *d;
unicode_char_t uc;
s = (unsigned char *)start;
d = (unsigned char *)buf;
while (s < (unsigned char *)end) {
if (*s < 0x80) {
/* US-ASCII character: copy unless it's
* an apostrophe.
*/
if (*s != '\'')
*d++ = tolower (*s);
s++;
} else {
char *next = unicode_get_utf8 (s, &uc);
if (uc >= 0xc0 && uc < 0xc0 + sizeof (utf8_trans)) {
signed char ch = utf8_trans[uc - 0xc0];
if (ch > 0)
*d++ = tolower (ch);
else {
*d++ = tolower (utf8_long_trans[-ch - 1][0]);
*d++ = tolower (utf8_long_trans[-ch - 1][1]);
}
s = next;
} else {
while (s < (unsigned char *)next)
*d++ = *s++;
}
}
}
*d = '\0';
}
enum { IBEX_ALPHA, IBEX_NONALPHA, IBEX_INVALID, IBEX_INCOMPLETE };
/* This incorporates parts of libunicode, because there's no way to
* force libunicode to not read past a certain point.
*/
static int
utf8_category (char *sp, char **snp, char *send)
{
unsigned char *p = (unsigned char *)sp, **np = (unsigned char **)snp;
unsigned char *end = (unsigned char *)send;
if (isascii (*p)) {
*np = p + 1;
if (isalpha (*p) || *p == '\'')
return IBEX_ALPHA;
return IBEX_NONALPHA;
} else {
unicode_char_t uc;
int more;
if ((*p & 0xe0) == 0xc0) {
more = 1;
uc = *p & 0x1f;
} else if ((*p & 0xf0) == 0xe0) {
more = 2;
uc = *p & 0x0f;
} else if ((*p & 0xf8) == 0xf0) {
more = 3;
uc = *p & 0x07;
} else if ((*p & 0xfc) == 0xf8) {
more = 4;
uc = *p & 0x03;
} else if ((*p & 0xfe) == 0xfc) {
more = 5;
uc = *p & 0x01;
} else
return IBEX_INVALID;
if (p + more > end)
return IBEX_INCOMPLETE;
while (more--) {
if ((*++p & 0xc0) != 0x80)
return IBEX_INVALID;
uc <<= 6;
uc |= *p & 0x3f;
}
*np = p + 1;
if (unicode_isalpha (uc))
return IBEX_ALPHA;
else
return IBEX_NONALPHA;
}
}
static ibex_file *
get_ibex_file (ibex *ib, char *name)
{
ibex_file *ibf;
ibf = g_tree_lookup (ib->files, name);
if (!ibf) {
ibf = g_malloc (sizeof (ibex_file));
ibf->name = strdup (name);
ibf->index = 0;
g_tree_insert (ib->files, ibf->name, ibf);
ib->dirty = TRUE;
}
return ibf;
}
static void
ref_word (ibex *ib, ibex_file *ibf, char *word)
{
GPtrArray *refs;
refs = g_hash_table_lookup (ib->words, word);
if (!refs) {
refs = g_ptr_array_new ();
g_hash_table_insert (ib->words, g_strdup (word), refs);
g_ptr_array_add (refs, ibf);
ib->dirty = TRUE;
} else if (g_ptr_array_index (refs, refs->len - 1) != ibf) {
g_ptr_array_add (refs, ibf);
ib->dirty = TRUE;
}
}
/**
* ibex_index_buffer: the lowest-level ibex indexing interface
* @ib: an ibex
* @name: the name of the file being indexed
* @buffer: a buffer containing data from the file
* @len: the length of @buffer
* @unread: an output argument containing the number of unread bytes
*
* This routine indexes up to @len bytes from @buffer into @ib.
* If @unread is NULL, the indexer assumes that the buffer ends on a
* word boundary, and will index all the way to the end of the
* buffer. If @unread is not NULL, and the buffer ends with an
* alphabetic character, the indexer will assume that the buffer has
* been cut off in the middle of a word, and return the number of
* un-indexed bytes at the end of the buffer in *@unread. The caller
* should then read in more data through whatever means it has
* and pass in the unread bytes from the original buffer, followed
* by the new data, on its next call.
*
* Return value: 0 on success, -1 on failure.
**/
int
ibex_index_buffer (ibex *ib, char *name, char *buffer,
size_t len, size_t *unread)
{
char *p, *q, *nq, *end, *word;
ibex_file *ibf = get_ibex_file (ib, name);
int wordsiz, cat;
end = buffer + len;
wordsiz = 20;
word = g_malloc (wordsiz);
p = buffer;
while (p < end) {
while (p < end) {
cat = utf8_category (p, &q, end);
if (cat != IBEX_NONALPHA)
break;
p = q;
}
if (p == end) {
g_free (word);
return 0;
} else if (cat == IBEX_INVALID) {
errno = EINVAL;
g_free (word);
return -1;
} else if (cat == IBEX_INCOMPLETE)
q = end;
while (q < end) {
cat = utf8_category (q, &nq, end);
if (cat != IBEX_ALPHA)
break;
q = nq;
}
if (cat == IBEX_INVALID ||
(cat == IBEX_INCOMPLETE && !unread)) {
errno = EINVAL;
g_free (word);
return -1;
} else if (cat == IBEX_INCOMPLETE || (q == end && unread)) {
*unread = end - p;
g_free (word);
return 0;
}
if (wordsiz < q - p + 1) {
wordsiz = q - p + 1;
word = g_realloc (word, wordsiz);
}
normalize_word (p, q, word);
ref_word (ib, ibf, word);
p = q;
}
if (unread)
*unread = 0;
g_free (word);
return 0;
}
