[nautilus/trash-rate-limit] trash-monitor: Rate limit updates

[Ondrej Holy <oholy src gnome org>]

commit 1ff11c57f5c8f260b39ce810126916c7a2e140a6
Author: Ondrej Holy <oholy redhat com>
Date:   Fri Jan 5 16:06:40 2018 +0100

    trash-monitor: Rate limit updates
    
    Trash monitor queries info from gvfsd-trash after each file monitor
    change which can be problematic when too many changes happen in
    a short time. Let's rate limit the number of queries...

 src/nautilus-trash-monitor.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
---
diff --git a/src/nautilus-trash-monitor.c b/src/nautilus-trash-monitor.c
index 318926f80..f4e6160a3 100644
--- a/src/nautilus-trash-monitor.c
+++ b/src/nautilus-trash-monitor.c
@@ -29,10 +29,14 @@
 #include <gio/gio.h>
 #include <string.h>
 
+#define UPDATE_RATE_SECONDS 5
+
 struct NautilusTrashMonitorDetails
 {
     gboolean empty;
     GFileMonitor *file_monitor;
+    gboolean pending;
+    gint timeout_id;
 };
 
 enum
@@ -53,6 +57,10 @@ nautilus_trash_monitor_finalize (GObject *object)
 
     trash_monitor = NAUTILUS_TRASH_MONITOR (object);
 
+    if (trash_monitor->details->timeout_id > 0)
+            g_source_remove (trash_monitor->details->timeout_id);
+    trash_monitor->details->timeout_id = 0;
+
     if (trash_monitor->details->file_monitor)
     {
         g_object_unref (trash_monitor->details->file_monitor);
@@ -131,11 +139,37 @@ trash_query_info_cb (GObject      *source,
     g_object_unref (trash_monitor);
 }
 
+static void schedule_update_info (NautilusTrashMonitor *trash_monitor);
+
+static gboolean
+schedule_update_info_cb (gpointer data)
+{
+  NautilusTrashMonitor *trash_monitor = data;
+
+  trash_monitor->details->timeout_id = 0;
+  if (trash_monitor->details->pending)
+  {
+        trash_monitor->details->pending = FALSE;
+        schedule_update_info (trash_monitor);
+  }
+
+  return G_SOURCE_REMOVE;
+}
+
 static void
 schedule_update_info (NautilusTrashMonitor *trash_monitor)
 {
     GFile *location;
 
+    /* Rate limit the updates to not flood the gvfsd-trash when too many changes
+     * happended in a short time.
+     */
+    if (trash_monitor->details->timeout_id > 0)
+    {
+            trash_monitor->details->pending = TRUE;
+            return;
+    }
+
     location = g_file_new_for_uri ("trash:///");
     g_file_query_info_async (location,
                              G_FILE_ATTRIBUTE_TRASH_ITEM_COUNT,
@@ -143,6 +177,9 @@ schedule_update_info (NautilusTrashMonitor *trash_monitor)
                              G_PRIORITY_DEFAULT, NULL,
                              trash_query_info_cb, g_object_ref (trash_monitor));
 
+    trash_monitor->details->timeout_id = g_timeout_add_seconds (UPDATE_RATE_SECONDS,
+                                                                schedule_update_info_cb,
+                                                                trash_monitor);
     g_object_unref (location);
 }
 
@@ -174,6 +211,8 @@ nautilus_trash_monitor_init (NautilusTrashMonitor *trash_monitor)
     location = g_file_new_for_uri ("trash:///");
 
     trash_monitor->details->file_monitor = g_file_monitor_file (location, 0, NULL, NULL);
+    trash_monitor->details->pending = FALSE;
+    trash_monitor->details->timeout_id = 0;
 
     g_signal_connect (trash_monitor->details->file_monitor, "changed",
                       (GCallback) file_changed, trash_monitor);