[PATCH/RFC 1/3] remote: refactor some logic into get_stale_heads()

[Jay Soffian <jaysoffian@gmail.com>]

Move the logic in builtin-remote.c which determines which local heads are stale
to remote.c so it can be used by other builtins.
---
 builtin-remote.c |   32 ++++++++------------------------
 remote.c         |   40 ++++++++++++++++++++++++++++++++++++++++
 remote.h         |    3 +++
 3 files changed, 51 insertions(+), 24 deletions(-)

diff --git a/builtin-remote.c b/builtin-remote.c
index 0777dd7..b48267b 100644
--- a/builtin-remote.c
+++ b/builtin-remote.c
@@ -227,32 +227,10 @@ struct ref_states {
 	int queried;
 };
 
-static int handle_one_branch(const char *refname,
-	const unsigned char *sha1, int flags, void *cb_data)
-{
-	struct ref_states *states = cb_data;
-	struct refspec refspec;
-
-	memset(&refspec, 0, sizeof(refspec));
-	refspec.dst = (char *)refname;
-	if (!remote_find_tracking(states->remote, &refspec)) {
-		struct string_list_item *item;
-		const char *name = abbrev_branch(refspec.src);
-		/* symbolic refs pointing nowhere were handled already */
-		if ((flags & REF_ISSYMREF) ||
-		    string_list_has_string(&states->tracked, name) ||
-		    string_list_has_string(&states->new, name))
-			return 0;
-		item = string_list_append(name, &states->stale);
-		item->util = xstrdup(refname);
-	}
-	return 0;
-}
-
 static int get_ref_states(const struct ref *remote_refs, struct ref_states *states)
 {
 	struct ref *fetch_map = NULL, **tail = &fetch_map;
-	struct ref *ref;
+	struct ref *ref, *stale_refs;
 	int i;
 
 	for (i = 0; i < states->remote->fetch_refspec_nr; i++)
@@ -268,11 +246,17 @@ static int get_ref_states(const struct ref *remote_refs, struct ref_states *stat
 		else
 			string_list_append(abbrev_branch(ref->name), &states->tracked);
 	}
+	stale_refs = get_stale_heads(states->remote, fetch_map);
+	for (ref = stale_refs; ref; ref = ref->next) {
+		struct string_list_item *item =
+			string_list_append(abbrev_branch(ref->name), &states->stale);
+		item->util = xstrdup(ref->name);
+	}
+	free_refs(stale_refs);
 	free_refs(fetch_map);
 
 	sort_string_list(&states->new);
 	sort_string_list(&states->tracked);
-	for_each_ref(handle_one_branch, states);
 	sort_string_list(&states->stale);
 
 	return 0;
diff --git a/remote.c b/remote.c
index 73d33f2..ee48b49 100644
--- a/remote.c
+++ b/remote.c
@@ -6,6 +6,7 @@
 #include "revision.h"
 #include "dir.h"
 #include "tag.h"
+#include "string-list.h"
 
 static struct refspec s_tag_refspec = {
 	0,
@@ -1586,3 +1587,42 @@ struct ref *guess_remote_head(const struct ref *head,
 
 	return list;
 }
+
+struct stale_heads_info {
+	struct remote *remote;
+	struct string_list *ref_names;
+	struct ref **stale_refs_tail;
+};
+
+static int get_stale_heads_cb(const char *refname,
+	const unsigned char *sha1, int flags, void *cb_data)
+{
+	struct stale_heads_info *info = cb_data;
+	struct refspec refspec;
+	memset(&refspec, 0, sizeof(refspec));
+	refspec.dst = (char *)refname;
+	if (!remote_find_tracking(info->remote, &refspec)) {
+		if (!((flags & REF_ISSYMREF) ||
+		    string_list_has_string(info->ref_names, refspec.src))) {
+			struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
+			hashcpy(ref->new_sha1, sha1);
+		}
+	}
+	return 0;
+}
+
+struct ref *get_stale_heads(struct remote *remote, struct ref *fetch_map)
+{
+	struct ref *ref, *stale_refs = NULL;
+	struct string_list ref_names = { NULL, 0, 0, 0 };
+	struct stale_heads_info info;
+	info.remote = remote;
+	info.ref_names = &ref_names;
+	info.stale_refs_tail = &stale_refs;
+	for (ref = fetch_map; ref; ref = ref->next)
+		string_list_append(ref->name, &ref_names);
+	sort_string_list(&ref_names);
+	for_each_ref(get_stale_heads_cb, &info);
+	string_list_clear(&ref_names, 0);
+	return stale_refs;
+}
diff --git a/remote.h b/remote.h
index 5db8420..d0aba81 100644
--- a/remote.h
+++ b/remote.h
@@ -154,4 +154,7 @@ struct ref *guess_remote_head(const struct ref *head,
 			      const struct ref *refs,
 			      int all);
 
+/* Return refs which no longer exist on remote */
+struct ref *get_stale_heads(struct remote *remote, struct ref *fetch_map);
+
 #endif
-- 
1.6.4.2