* matchings spread over multiple fragments, then go BM.
*/
-#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
+#include <linux/ctype.h>
#include <linux/textsearch.h>
/* Alphabet size, use ASCII */
struct ts_bm *bm = ts_config_priv(conf);
unsigned int i, text_len, consumed = state->offset;
const u8 *text;
- int shift = bm->patlen, bs;
+ int shift = bm->patlen - 1, bs;
+ const u8 icase = conf->flags & TS_IGNORECASE;
for (;;) {
text_len = conf->get_next_block(consumed, &text, conf, state);
DEBUGP("Searching in position %d (%c)\n",
shift, text[shift]);
for (i = 0; i < bm->patlen; i++)
- if (text[shift-i] != bm->pattern[bm->patlen-1-i])
+ if ((icase ? toupper(text[shift-i])
+ : text[shift-i])
+ != bm->pattern[bm->patlen-1-i])
goto next;
/* London calling... */
return UINT_MAX;
}
-static void compute_prefix_tbl(struct ts_bm *bm, const u8 *pattern,
- unsigned int len)
+static int subpattern(u8 *pattern, int i, int j, int g)
{
- int i, j, ended, l[ASIZE];
+ int x = i+g-1, y = j+g-1, ret = 0;
+
+ while(pattern[x--] == pattern[y--]) {
+ if (y < 0) {
+ ret = 1;
+ break;
+ }
+ if (--g == 0) {
+ ret = pattern[i-1] != pattern[j-1];
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static void compute_prefix_tbl(struct ts_bm *bm, int flags)
+{
+ int i, j, g;
for (i = 0; i < ASIZE; i++)
- bm->bad_shift[i] = len;
- for (i = 0; i < len - 1; i++)
- bm->bad_shift[pattern[i]] = len - 1 - i;
+ bm->bad_shift[i] = bm->patlen;
+ for (i = 0; i < bm->patlen - 1; i++) {
+ bm->bad_shift[bm->pattern[i]] = bm->patlen - 1 - i;
+ if (flags & TS_IGNORECASE)
+ bm->bad_shift[tolower(bm->pattern[i])]
+ = bm->patlen - 1 - i;
+ }
/* Compute the good shift array, used to match reocurrences
* of a subpattern */
- for (i = 1; i < bm->patlen; i++) {
- for (j = 0; j < bm->patlen && bm->pattern[bm->patlen - 1 - j]
- == bm->pattern[bm->patlen - 1 - i - j]; j++);
- l[i] = j;
- }
-
bm->good_shift[0] = 1;
for (i = 1; i < bm->patlen; i++)
bm->good_shift[i] = bm->patlen;
- for (i = bm->patlen - 1; i > 0; i--)
- bm->good_shift[l[i]] = i;
- ended = 0;
- for (i = 0; i < bm->patlen; i++) {
- if (l[i] == bm->patlen - 1 - i)
- ended = i;
- if (ended)
- bm->good_shift[i] = ended;
+ for (i = bm->patlen-1, g = 1; i > 0; g++, i--) {
+ for (j = i-1; j >= 1-g ; j--)
+ if (subpattern(bm->pattern, i, j, g)) {
+ bm->good_shift[g] = bm->patlen-j-g;
+ break;
+ }
}
}
static struct ts_config *bm_init(const void *pattern, unsigned int len,
- gfp_t gfp_mask)
+ gfp_t gfp_mask, int flags)
{
struct ts_config *conf;
struct ts_bm *bm;
+ int i;
unsigned int prefix_tbl_len = len * sizeof(unsigned int);
size_t priv_size = sizeof(*bm) + len + prefix_tbl_len;
if (IS_ERR(conf))
return conf;
+ conf->flags = flags;
bm = ts_config_priv(conf);
bm->patlen = len;
bm->pattern = (u8 *) bm->good_shift + prefix_tbl_len;
- compute_prefix_tbl(bm, pattern, len);
- memcpy(bm->pattern, pattern, len);
+ if (flags & TS_IGNORECASE)
+ for (i = 0; i < len; i++)
+ bm->pattern[i] = toupper(((u8 *)pattern)[i]);
+ else
+ memcpy(bm->pattern, pattern, len);
+ compute_prefix_tbl(bm, flags);
return conf;
}