Clean up reflog unreachability pruning decision

This clarifies the pruning rules for unreachable commits by having a
separate helpder function for the unreachability decision.

It's preparation for actual bigger changes to come to speed up the
decision when the reachability calculations become a bottleneck.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-reflog.c b/builtin-reflog.c
index d95f515f2e32aa71c3a09fe5ed9486f352713360..a07960ff5e395b9e4fdd9816daf4da06b89162e2 100644 (file)
--- a/builtin-reflog.c
+++ b/builtin-reflog.c
@@ -209,6 +209,31 @@ static int keep_entry(struct commit **it, unsigned char *sha1)
        return 1;
 }
 
+static int unreachable(struct expire_reflog_cb *cb, struct commit *commit, unsigned char *sha1)
+{
+       /*
+        * We may or may not have the commit yet - if not, look it
+        * up using the supplied sha1.
+        */
+       if (!commit) {
+               if (is_null_sha1(sha1))
+                       return 0;
+
+               commit = lookup_commit_reference_gently(sha1, 1);
+
+               /* Not a commit -- keep it */
+               if (!commit)
+                       return 0;
+       }
+
+       /* Reachable from the current ref?  Don't prune. */
+       if (in_merge_bases(commit, &cb->ref_commit, 1))
+               return 0;
+
+       /* We can't reach it - prune it. */
+       return 1;
+}
+
 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
                const char *email, unsigned long timestamp, int tz,
                const char *message, void *cb_data)
@@ -230,12 +255,7 @@ static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
        if (timestamp < cb->cmd->expire_unreachable) {
                if (!cb->ref_commit)
                        goto prune;
-               if (!old && !is_null_sha1(osha1))
-                       old = lookup_commit_reference_gently(osha1, 1);
-               if (!new && !is_null_sha1(nsha1))
-                       new = lookup_commit_reference_gently(nsha1, 1);
-               if ((old && !in_merge_bases(old, &cb->ref_commit, 1)) ||
-                   (new && !in_merge_bases(new, &cb->ref_commit, 1)))
+               if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
                        goto prune;
        }