trash: Check modification time to avoid rereading

Rereading of trash dirs is pretty expensive and unfortunately it is
performed more often with recent changes. Check modification time of
each trash dir in order to avoid needless rereading, because simple
query_info call is much faster than enumeration.

https://bugzilla.gnome.org/show_bug.cgi?id=711459

1 files changed, 39 insertions, 0 deletions

diff --git a/daemon/trashlib/trashdir.c b/daemon/trashlib/trashdir.c
index 897ccacd..a11e0980 100644
--- a/daemon/trashlib/trashdir.c
+++ b/daemon/trashlib/trashdir.c
@@ -21,6 +21,7 @@ struct OPAQUE_TYPE__TrashDir
   GFile *directory;
   GFile *topdir;
   gboolean is_homedir;
+  GTimeVal mtime;
 
   DirWatch *watch;
   GFileMonitor *monitor;
@@ -49,6 +50,26 @@ compare_basename (gconstpointer a,
 }
 
 static void
+trash_dir_query_mtime (TrashDir *dir, GTimeVal *mtime)
+{
+  GFileInfo *info;
+
+  info = g_file_query_info (dir->directory, G_FILE_ATTRIBUTE_TIME_MODIFIED ","
+                                            G_FILE_ATTRIBUTE_TIME_MODIFIED_USEC,
+                            G_FILE_QUERY_INFO_NONE, NULL, NULL);
+  if (info)
+    {
+      g_file_info_get_modification_time (info, mtime);
+      g_object_unref (info);
+    }
+  else
+    {
+      mtime->tv_sec = 0;
+      mtime->tv_usec = 0;
+    }
+}
+
+static void
 trash_dir_set_files (TrashDir *dir,
                      GSList   *items)
 {
@@ -106,6 +127,7 @@ trash_dir_enumerate (TrashDir *dir)
   GFileEnumerator *enumerator;
   GSList *files = NULL;
 
+  trash_dir_query_mtime (dir, &dir->mtime);
   enumerator = g_file_enumerate_children (dir->directory,
                                           G_FILE_ATTRIBUTE_STANDARD_NAME,
                                           G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
@@ -298,9 +320,26 @@ dir_exists (GFile *directory,
   return result;
 }
 
+static gboolean
+trash_dir_is_dirty (TrashDir *dir)
+{
+  GTimeVal mtime;
+
+  trash_dir_query_mtime (dir, &mtime);
+
+  if (mtime.tv_sec == dir->mtime.tv_sec &&
+      mtime.tv_usec == dir->mtime.tv_usec)
+    return FALSE;
+
+  return TRUE;
+}
+
 void
 trash_dir_rescan (TrashDir *dir)
 {
+  if (!trash_dir_is_dirty (dir))
+    return;
+
   if (dir->watch)
     dir_watch_check (dir->watch);