limit "contains" traversals based on commit timestamp

[git.git] / builtin / tag.c

diff --git a/builtin/tag.c b/builtin/tag.c
index f7a7943c9ddf783270addc3a50b23496f44fe175..72140b3986098593185d43d3014d0fa9c3ca60c1 100644 (file)
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -25,6 +25,8 @@ static const char * const git_tag_usage[] = {
 
 static char signingkey[1000];
 
+static int core_clock_skew = -1;
+
 struct tag_filter {
        const char *pattern;
        int lines;
@@ -42,7 +44,8 @@ static int in_commit_list(const struct commit_list *want, struct commit *c)
 }
 
 static int contains_recurse(struct commit *candidate,
-                           const struct commit_list *want)
+                           const struct commit_list *want,
+                           unsigned long cutoff)
 {
        struct commit_list *p;
 
@@ -59,9 +62,13 @@ static int contains_recurse(struct commit *candidate,
        if (parse_commit(candidate) < 0)
                return 0;
 
+       /* stop searching if we go too far back in time */
+       if (candidate->date < cutoff)
+               return 0;
+
        /* Otherwise recurse and mark ourselves for future traversals. */
        for (p = candidate->parents; p; p = p->next) {
-               if (contains_recurse(p->item, want)) {
+               if (contains_recurse(p->item, want, cutoff)) {
                        candidate->object.flags |= TMP_MARK;
                        return 1;
                }
@@ -72,7 +79,22 @@ static int contains_recurse(struct commit *candidate,
 
 static int contains(struct commit *candidate, const struct commit_list *want)
 {
-       return contains_recurse(candidate, want);
+       unsigned long cutoff = 0;
+
+       if (core_clock_skew >= 0) {
+               const struct commit_list *c;
+               unsigned long min_date = ULONG_MAX;
+               for (c = want; c; c = c->next) {
+                       if (parse_commit(c->item) < 0)
+                               continue;
+                       if (c->item->date < min_date)
+                               min_date = c->item->date;
+               }
+               if (min_date > core_clock_skew)
+                       cutoff = min_date - core_clock_skew;
+       }
+
+       return contains_recurse(candidate, want, cutoff);
 }
 
 static int show_reference(const char *refname, const unsigned char *sha1,
@@ -279,6 +301,14 @@ static int git_tag_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
+       if (!strcmp(var, "core.clockskew")) {
+               if (!value || !strcmp(value, "none"))
+                       core_clock_skew = -1;
+               else
+                       core_clock_skew = git_config_int(var, value);
+               return 0;
+       }
+
        return git_default_config(var, value, cb);
 }