Ref-count the filespecs used by diffcore
Rather than copy the filespecs when introducing new versions of them
(for rename or copy detection), use a refcount and increment the count
when reusing the diff_filespec.
This avoids unnecessary allocations, but the real reason behind this is
a future enhancement: we will want to track shared data across the
copy/rename detection. In order to efficiently notice when a filespec
is used by a rename, the rename machinery wants to keep track of a
rename usage count which is shared across all different users of the
filespec.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/diff.c b/diff.c
index dfb8595..0b320f6 100644
--- a/diff.c
+++ b/diff.c
@@ -1440,9 +1440,18 @@
memset(spec, 0, sizeof(*spec));
spec->path = (char *)(spec + 1);
memcpy(spec->path, path, namelen+1);
+ spec->count = 1;
return spec;
}
+void free_filespec(struct diff_filespec *spec)
+{
+ if (!--spec->count) {
+ diff_free_filespec_data(spec);
+ free(spec);
+ }
+}
+
void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
unsigned short mode)
{
@@ -2435,10 +2444,8 @@
void diff_free_filepair(struct diff_filepair *p)
{
- diff_free_filespec_data(p->one);
- diff_free_filespec_data(p->two);
- free(p->one);
- free(p->two);
+ free_filespec(p->one);
+ free_filespec(p->two);
free(p);
}
