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Atari Mega Archive 1
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agrepsrc.zoo
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bitap.c
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C/C++ Source or Header
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1993-01-19
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6KB
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158 lines
/* Copyright (c) 1991 Sun Wu and Udi Manber. All Rights Reserved. */
/* if the pattern is not simple fixed pattern, then after preprocessing */
/* and generating the masks, the program goes here. four cases: 1. */
/* the pattern is simple regular expression and no error, then do the */
/* matching here. 2. the pattern is simple regular expression and */
/* unit cost errors are allowed: then go to asearch(). */
/* 3. the pattern is simple regular expression, and the edit cost is */
/* not uniform, then go to asearch1(). */
/* if the pattern is regular expression then go to re() if M < 14, */
/* else go to re1() */
/* input parameters: old_D_pat: delimiter pattern. */
/* fd, input file descriptor, M: size of pattern, D: # of errors. */
#include "agrep.h"
extern unsigned Init1, D_endpos, endposition, Init[], Mask[], Bit[];
extern int DELIMITER, FILENAMEONLY, D_length, I, AND, REGEX, JUMP, INVERSE;
extern char D_pattern[];
extern int TRUNCATE, DD, S;
extern char Progname[], CurrentFileName[];
extern int num_of_matched;
/* bitap dispatches job */
bitap(old_D_pat, Pattern, fd, M, D)
char old_D_pat[], *Pattern; int fd, M, D;
{
char c;
register unsigned r1, r2, r3, CMask, i;
register unsigned end, endpos, r_Init1;
register unsigned D_Mask;
int ResidueSize , FIRSTROUND, lasti, print_end, j, num_read;
int k;
char buffer[Max_record+Max_record+BlockSize];
D_length = strlen(old_D_pat);
for(i=0; i<D_length; i++) if(old_D_pat[i] == '^' || old_D_pat[i] == '$')
old_D_pat[i] = '\n';
if (REGEX) {
if (D > 4) {
fprintf(stderr, "%s: the maximum number of erorrs allowed for full regular expression is 4\n", Progname);
exit(2);
}
if (M <= SHORTREG) { re(fd, M, D); /* SUN: need to find a even point */
return; }
else { re1(fd, M, D);
return; }
}
if (D > 0 && JUMP == ON)
{ asearch1(old_D_pat, fd, D); return; }
if (D > 0)
{ asearch(old_D_pat, fd, D); return; }
if(I == 0) Init1 = 037777777777;
j=0;
lasti = Max_record;
buffer[Max_record-1] = '\n';
r_Init1 = Init1;
r1 = r2 = r3 = Init[0];
endpos = D_endpos;
buffer[Max_record-1] = '\n';
D_Mask = D_endpos;
for(i=1 ; i<D_length; i++) D_Mask = (D_Mask << 1) | D_Mask;
D_Mask = ~D_Mask;
FIRSTROUND = ON;
while ((num_read = fill_buf(fd, buffer + Max_record, Max_record)) > 0)
{
i=Max_record; end = Max_record + num_read;
if(FIRSTROUND) { i = Max_record - 1 ;
if(DELIMITER) {
for(k=0; k<D_length; k++) {
if(old_D_pat[k] != buffer[Max_record+k]) break;
}
if(k>=D_length) j--;
}
FIRSTROUND = OFF; }
if(num_read < BlockSize) {
strncpy(buffer+Max_record+num_read, old_D_pat, D_length);
end = end + D_length;
buffer[end] = '\0';
}
while (i < end)
{
c = buffer[i++];
CMask = Mask[c];
r1 = r_Init1 & r3;
r2 = (( r3 >> 1 ) & CMask) | r1;
if ( r2 & endpos ) {
j++;
if(((AND == 1) && ((r2 & endposition) == endposition)) || ((AND == 0) && (r2 & endposition)) ^ INVERSE )
{
if(FILENAMEONLY) {
num_of_matched++;
printf("%s\n", CurrentFileName);
return; }
print_end = i - D_length - 1;
if(!(lasti >= Max_record+num_read - 1))
output(buffer, lasti, print_end, j);
}
lasti = i - D_length;
TRUNCATE = OFF;
r2 = r3 = r1 = Init[0];
r1 = r_Init1 & r3;
r2 = ((( r2 >> 1) & CMask) | r1 ) & D_Mask;
}
c = buffer[i++];
CMask = Mask[c];
r1 = r_Init1 & r2;
r3 = (( r2 >> 1 ) & CMask) | r1;
if ( r3 & endpos ) {
j++;
if(((AND == 1) && ((r3 & endposition) == endposition)) || ((AND == 0) && (r3 & endposition)) ^ INVERSE )
{
if(FILENAMEONLY) {
num_of_matched++;
printf("%s\n", CurrentFileName);
return; }
print_end = i - D_length - 1;
if(!(lasti >= Max_record+num_read - 1))
output(buffer, lasti, print_end, j);
}
lasti = i - D_length ;
TRUNCATE = OFF;
r2 = r3 = r1 = Init[0];
r1 = r_Init1 & r2;
r3 = ((( r2 >> 1) & CMask) | r1 ) & D_Mask;
}
}
ResidueSize = num_read + Max_record - lasti;
if(ResidueSize > Max_record) {
ResidueSize = Max_record;
TRUNCATE = ON;
}
strncpy(buffer+Max_record-ResidueSize, buffer+lasti, ResidueSize);
lasti = Max_record - ResidueSize;
if(lasti < 0) {
lasti = 1;
}
}
return;
}
fill_buf(fd, buf, record_size)
int fd, record_size; unsigned char *buf;
{
int num_read=1;
int total_read=0;
while(total_read < record_size && num_read > 0) {
num_read = read(fd, buf+total_read, 4096);
total_read = total_read + num_read;
}
return(total_read);
}