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git/diffcore-pickaxe.c
René Scharfe 50fd6997c6 pickaxe: count regex matches only once
When --pickaxe-regex is used, forward past the end of matches instead of
advancing to the byte after their start.  This way matches count only
once, even if the regular expression matches their tail -- like in the
fixed-string fork of the code.

E.g.: /.*/ used to count the number of bytes instead of the number of
lines.  /aa/ resulted in a count of two in "aaa" instead of one.

Also document the fact that regexec() needs a NUL-terminated string as
its second argument by adding an assert().

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-03-17 15:10:12 -07:00

139 lines
3.2 KiB
C

/*
* Copyright (C) 2005 Junio C Hamano
*/
#include "cache.h"
#include "diff.h"
#include "diffcore.h"
static unsigned int contains(struct diff_filespec *one,
const char *needle, unsigned long len,
regex_t *regexp)
{
unsigned int cnt;
unsigned long sz;
const char *data;
if (diff_populate_filespec(one, 0))
return 0;
if (!len)
return 0;
sz = one->size;
data = one->data;
cnt = 0;
if (regexp) {
regmatch_t regmatch;
int flags = 0;
assert(data[sz] == '\0');
while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
flags |= REG_NOTBOL;
data += regmatch.rm_eo;
if (*data && regmatch.rm_so == regmatch.rm_eo)
data++;
cnt++;
}
} else { /* Classic exact string match */
while (sz) {
const char *found = memmem(data, sz, needle, len);
if (!found)
break;
sz -= found - data + len;
data = found + len;
cnt++;
}
}
diff_free_filespec_data(one);
return cnt;
}
void diffcore_pickaxe(const char *needle, int opts)
{
struct diff_queue_struct *q = &diff_queued_diff;
unsigned long len = strlen(needle);
int i, has_changes;
regex_t regex, *regexp = NULL;
struct diff_queue_struct outq;
outq.queue = NULL;
outq.nr = outq.alloc = 0;
if (opts & DIFF_PICKAXE_REGEX) {
int err;
err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
if (err) {
/* The POSIX.2 people are surely sick */
char errbuf[1024];
regerror(err, &regex, errbuf, 1024);
regfree(&regex);
die("invalid pickaxe regex: %s", errbuf);
}
regexp = &regex;
}
if (opts & DIFF_PICKAXE_ALL) {
/* Showing the whole changeset if needle exists */
for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
struct diff_filepair *p = q->queue[i];
if (!DIFF_FILE_VALID(p->one)) {
if (!DIFF_FILE_VALID(p->two))
continue; /* ignore unmerged */
/* created */
if (contains(p->two, needle, len, regexp))
has_changes++;
}
else if (!DIFF_FILE_VALID(p->two)) {
if (contains(p->one, needle, len, regexp))
has_changes++;
}
else if (!diff_unmodified_pair(p) &&
contains(p->one, needle, len, regexp) !=
contains(p->two, needle, len, regexp))
has_changes++;
}
if (has_changes)
return; /* not munge the queue */
/* otherwise we will clear the whole queue
* by copying the empty outq at the end of this
* function, but first clear the current entries
* in the queue.
*/
for (i = 0; i < q->nr; i++)
diff_free_filepair(q->queue[i]);
}
else
/* Showing only the filepairs that has the needle */
for (i = 0; i < q->nr; i++) {
struct diff_filepair *p = q->queue[i];
has_changes = 0;
if (!DIFF_FILE_VALID(p->one)) {
if (!DIFF_FILE_VALID(p->two))
; /* ignore unmerged */
/* created */
else if (contains(p->two, needle, len, regexp))
has_changes = 1;
}
else if (!DIFF_FILE_VALID(p->two)) {
if (contains(p->one, needle, len, regexp))
has_changes = 1;
}
else if (!diff_unmodified_pair(p) &&
contains(p->one, needle, len, regexp) !=
contains(p->two, needle, len, regexp))
has_changes = 1;
if (has_changes)
diff_q(&outq, p);
else
diff_free_filepair(p);
}
if (opts & DIFF_PICKAXE_REGEX) {
regfree(&regex);
}
free(q->queue);
*q = outq;
return;
}