Junio C Hamano schrieb:
> -static unsigned int count_match(int one_or_more,
> - struct diff_filespec *one,
> - const char *needle, unsigned long len,
> - regex_t *regexp)
> +static unsigned int count_match_internal(int one_or_more,
> + const char *data, unsigned long sz,
> + const char *needle, unsigned long len,
> + regex_t *regexp)
> {
I don't especially like flags like one_or_more. Having two functions
(which possibly call a common function that does most of the work) is
nicer. And it's a bit sad here because there already are two functions
with nice names: count_match() and has_match(). But, well, since the
functions are not exported anyway it doesn't matter much.
> @@ -29,16 +20,14 @@ static unsigned int count_match(int one_or_more,
> while (*data && !regexec(regexp, data, 1, ®match, flags)) {
> flags |= REG_NOTBOL;
> data += regmatch.rm_so;
> - if (*data) data++;
> + if (*data)
> + data++;
> cnt++;
> if (one_or_more)
> break;
> }
> -
> - } else { /* Classic exact string match */
> - /* Yes, I've heard of strstr(), but the thing is *data may
> - * not be NUL terminated. Sue me.
> - */
> + } else {
> + /* data many not be NUL terminated; we cannot use strstr() */
That looks fishy to me. regexec() expects data to be a NUL-terminated
string, so either the comment is wrong or the regexp case needs to take
better care to add a NUL at the end of the buffer.
In any case, there is also memmem(), which uses the same fast algorithm
as strstr() in recent glibc versions. Like this?
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index f4870b4..4c19967 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -11,7 +11,6 @@ static unsigned int count_match_internal(int one_or_more,
regex_t *regexp)
{
unsigned int cnt = 0;
- unsigned long offset;
if (regexp) {
regmatch_t regmatch;
@@ -27,15 +26,15 @@ static unsigned int count_match_internal(int one_or_more,
break;
}
} else {
- /* data many not be NUL terminated; we cannot use strstr() */
- for (offset = 0; offset + len <= sz; offset++) {
- /* we count non-overlapping occurrences of needle */
- if (!memcmp(needle, data + offset, len)) {
- offset += len - 1;
- cnt++;
- if (one_or_more)
- break;
- }
+ while (sz) {
+ const char *found = memmem(data, sz, needle, len);
+ if (!found)
+ break;
+ sz -= found - data + len;
+ data = found + len;
+ cnt++;
+ if (one_or_more)
+ break;
}
}
return cnt;
--
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