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#include "rabincarp.h"
int rlsi_hash_reset(rol_hash_isearch *rlh)
{
rlh->pow = 1;
rlh->pattern_len = 0;
rlh->pattern_hash = 0;
rlh->text_hash = 0;
rlh->text_len = 0;
rlh->text = NULL;
rlh->pattern = NULL;
rlh->iter_pos = 0;
rlh->count = 0;
rlh->pre_text = NULL;
rlh->chunk_done = 0;
return 0;
}
int rlsi_hash_init(rol_hash_isearch *rlh, int b, int m)
{
rlh->b = b;
rlh->m = m;
rlsi_hash_reset(rlh);
return 0;
}
int rlsi_hash_precalc(rol_hash_isearch *rlh, char *pattern, int plen, char *text, int tlen)
{
int i;
if (tlen<plen)
{
return -1;
}
rlh->text_len = tlen;
rlh->text = text;
rlh->pattern = pattern;
rlh->pattern_len = plen;
rlh->pow = 1;
for (i=0; i<plen-1; i++)
{
rlh->pow = (rlh->pow * rlh->b) % rlh->m;
}
rlh->text_hash = 0;
rlh->pattern_hash = 0;
for (i=0;i<plen;i++)
{
rlh->pattern_hash = (rlh->pattern_hash * rlh->b + pattern[i]) % rlh->m;
rlh->text_hash = (rlh->text_hash * rlh->b + text[i]) % rlh->m;
}
//printf("pow %d\n",rlh->pow);
//printf("pattern %d\n",rlh->pattern_hash);
//printf("text %d\n",rlh->text_hash);
//set buffer size for presaved text
rlh->pre_text = malloc(plen);//dont check err =P, mem leak here
rlh->count = 0;
return 0;
}
//run after prepararion step
int rlsi_hash_search(rol_hash_isearch *rlh, char *pattern, int plen, char *text, int tlen)
{
int j=0;
int found=0;
if ((rlh->text == NULL) && (rlh->pattern == NULL))
{
rlsi_hash_precalc(rlh, pattern, plen, text, tlen);
}
if (rlh->chunk_done == 1)
{
rlh->chunk_done = 0;
rlh->text_len = tlen;
}
//printf("while %d",rlh->text_len-rlh->pattern_len);
//while (rlh->iter_pos<=(rlh->text_len-rlh->pattern_len))
while (rlh->iter_pos<=(rlh->text_len-rlh->pattern_len))
{
//hashes are matching
if (rlh->text_hash == rlh->pattern_hash)
{
//printf("2\n");
//check if string match
for (j=0;j<rlh->pattern_len;j++)
{
//???
char i_c=0;
int k=rlh->iter_pos+j;
if (k<0)
{
i_c = rlh->pre_text[rlh->pattern_len+k];
} else
{
//i_c = rlh->text[rlh->iter_pos+j];
i_c = text[rlh->iter_pos+j];
}
if (i_c != rlh->pattern[j])
break;
}
if (j == rlh->pattern_len)
{
//???
//printf("Found pattern at %d\n",rlh->iter_pos+1);
//printf("Found pattern at %d\n",rlh->count);
found = 1;
}
}
//???
if (rlh->iter_pos < rlh->text_len - rlh->pattern_len)
{
//printf("1\n");
//???
char i_c;
if (rlh->iter_pos < 0)
{
i_c = rlh->pre_text[rlh->pattern_len+rlh->iter_pos];
} else
{
//i_c = rlh->text[rlh->iter_pos];
i_c = text[rlh->iter_pos];
}
//printf("CHAR: %c\n",i_c);
//rlh->text_hash = ( rlh->b *( rlh->text_hash - i_c*rlh->pow) + rlh->text[rlh->iter_pos+rlh->pattern_len] ) % rlh->m;
rlh->text_hash = ( rlh->b *( rlh->text_hash - i_c*rlh->pow) + text[rlh->iter_pos+rlh->pattern_len] ) % rlh->m;
//printf("text %d\n",rlh->text_hash);
if (rlh->text_hash < 0)
{
rlh->text_hash = rlh->text_hash + rlh->m;
}
}
//iter over current buffer
rlh->iter_pos += 1;
//total data that have been iterated
rlh->count += 1;
if (found == 1)
{
//rlh->count -= 1;
return 1;
}
//iter over current buffer
//rlh->iter_pos += 1;
//total data that have been iterated
//rlh->count += 1;
//printf("rlh->iter_pos %d\n",rlh->iter_pos);
//printf("rlh->count %d\n",rlh->count);
}
//printf("tlen %d\n",tlen);
//exit from while loop because end of the buffer, iter is +1 element larger
//copy pattern to intermidiate buffer
//if ((rlh->iter_pos)==(rlh->text_len - rlh->pattern_len+1))
{
//copy last bit of buffer to further processing
//memcpy(rlh->pre_text, &rlh->text[rlh->iter_pos], rlh->pattern_len);
memcpy(rlh->pre_text, &text[rlh->iter_pos-1], rlh->pattern_len);
//printf("end of chunk\n");
//rlh->count -= 1;
//printf("count %d\n",rlh->count);
rlh->chunk_done = 1;
rlh->iter_pos = -rlh->pattern_len;
}
//exit_loop:
//chunk finished search new need to be supplied pal
//printf("0\n");
rlh->count -= 1;
return 0;
}
int rlsi_hash_get(rol_hash_isearch *rlh)
{
//return rlh->iter_pos;
return rlh->count;
}
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