rerere: gc and clear

Adjust "git rerere gc" and "git rerere clear" to the new world order
with rerere database with multiple variants for the same shape of
conflicts.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 48 insertions, 39 deletions

diff --git a/rerere.c b/rerere.c
index 353227cdaf..3d4dd33724 100644
--- a/rerere.c
+++ b/rerere.c
@@ -1081,29 +1081,16 @@ int rerere_forget(struct pathspec *pathspec)
  * Garbage collection support
  */
 
-/*
- * Note that this is not reentrant but is used only one-at-a-time
- * so it does not matter right now.
- */
-static struct rerere_id *dirname_to_id(const char *name)
-{
-	static struct rerere_id id;
-	id.collection = find_rerere_dir(name);
-	return &id;
-}
-
-static time_t rerere_created_at(const char *dir_name)
+static time_t rerere_created_at(struct rerere_id *id)
 {
 	struct stat st;
-	struct rerere_id *id = dirname_to_id(dir_name);
 
 	return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
 }
 
-static time_t rerere_last_used_at(const char *dir_name)
+static time_t rerere_last_used_at(struct rerere_id *id)
 {
 	struct stat st;
-	struct rerere_id *id = dirname_to_id(dir_name);
 
 	return stat(rerere_path(id, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
 }
@@ -1113,15 +1100,28 @@ static time_t rerere_last_used_at(const char *dir_name)
  */
 static void unlink_rr_item(struct rerere_id *id)
 {
-	unlink(rerere_path(id, "thisimage"));
-	unlink(rerere_path(id, "preimage"));
-	unlink(rerere_path(id, "postimage"));
-	/*
-	 * NEEDSWORK: what if this rmdir() fails?  Wouldn't we then
-	 * assume that we already have preimage recorded in
-	 * do_plain_rerere()?
-	 */
-	rmdir(rerere_path(id, NULL));
+	unlink_or_warn(rerere_path(id, "thisimage"));
+	remove_variant(id);
+	id->collection->status[id->variant] = 0;
+}
+
+static void prune_one(struct rerere_id *id, time_t now,
+		      int cutoff_resolve, int cutoff_noresolve)
+{
+	time_t then;
+	int cutoff;
+
+	then = rerere_last_used_at(id);
+	if (then)
+		cutoff = cutoff_resolve;
+	else {
+		then = rerere_created_at(id);
+		if (!then)
+			return;
+		cutoff = cutoff_noresolve;
+	}
+	if (then < now - cutoff * 86400)
+		unlink_rr_item(id);
 }
 
 void rerere_gc(struct string_list *rr)
@@ -1129,8 +1129,8 @@ void rerere_gc(struct string_list *rr)
 	struct string_list to_remove = STRING_LIST_INIT_DUP;
 	DIR *dir;
 	struct dirent *e;
-	int i, cutoff;
-	time_t now = time(NULL), then;
+	int i;
+	time_t now = time(NULL);
 	int cutoff_noresolve = 15;
 	int cutoff_resolve = 60;
 
@@ -1142,25 +1142,32 @@ void rerere_gc(struct string_list *rr)
 		die_errno("unable to open rr-cache directory");
 	/* Collect stale conflict IDs ... */
 	while ((e = readdir(dir))) {
+		struct rerere_dir *rr_dir;
+		struct rerere_id id;
+		int now_empty;
+
 		if (is_dot_or_dotdot(e->d_name))
 			continue;
-
-		then = rerere_last_used_at(e->d_name);
-		if (then) {
-			cutoff = cutoff_resolve;
-		} else {
-			then = rerere_created_at(e->d_name);
-			if (!then)
-				continue;
-			cutoff = cutoff_noresolve;
+		rr_dir = find_rerere_dir(e->d_name);
+		if (!rr_dir)
+			continue; /* or should we remove e->d_name? */
+
+		now_empty = 1;
+		for (id.variant = 0, id.collection = rr_dir;
+		     id.variant < id.collection->status_nr;
+		     id.variant++) {
+			prune_one(&id, now, cutoff_resolve, cutoff_noresolve);
+			if (id.collection->status[id.variant])
+				now_empty = 0;
 		}
-		if (then < now - cutoff * 86400)
+		if (now_empty)
 			string_list_append(&to_remove, e->d_name);
 	}
 	closedir(dir);
-	/* ... and then remove them one-by-one */
+
+	/* ... and then remove the empty directories */
 	for (i = 0; i < to_remove.nr; i++)
-		unlink_rr_item(dirname_to_id(to_remove.items[i].string));
+		rmdir(git_path("rr-cache/%s", to_remove.items[i].string));
 	string_list_clear(&to_remove, 0);
 }
 
@@ -1177,8 +1184,10 @@ void rerere_clear(struct string_list *merge_rr)
 
 	for (i = 0; i < merge_rr->nr; i++) {
 		struct rerere_id *id = merge_rr->items[i].util;
-		if (!has_rerere_resolution(id))
+		if (!has_rerere_resolution(id)) {
 			unlink_rr_item(id);
+			rmdir(rerere_path(id, NULL));
+		}
 	}
 	unlink_or_warn(git_path("MERGE_RR"));
 }