[evolution-data-server/gnome-3-16] Bug 751657 - ESource can be removed after its property change

[Milan Crha <mcrha src gnome org>]

commit 045d5157599365e314e648738fe75daf51334b73
Author: Milan Crha <mcrha redhat com>
Date:   Wed Aug 5 16:24:15 2015 +0200

    Bug 751657 - ESource can be removed after its property change

 libebackend/e-source-registry-server.c |  212 ++++++++++++++++++++++++++++----
 1 files changed, 186 insertions(+), 26 deletions(-)
---
diff --git a/libebackend/e-source-registry-server.c b/libebackend/e-source-registry-server.c
index 61aa39a..3edd829 100644
--- a/libebackend/e-source-registry-server.c
+++ b/libebackend/e-source-registry-server.c
@@ -66,6 +66,10 @@ struct _ESourceRegistryServerPrivate {
        GMutex orphans_lock;
 
        ESourceCredentialsProvider *credentials_provider;
+
+       GMutex file_monitor_lock;
+       GHashTable *file_monitor_events; /* gchar *uid ~> FileEventData * */
+       GSource *file_monitor_source;
 };
 
 enum {
@@ -414,44 +418,112 @@ source_registry_server_reload_cb (EDBusSourceManager *dbus_interface,
        return TRUE;
 }
 
+typedef struct _FileEventData {
+       GFile *file;
+       GFileMonitorEvent event_type;
+} FileEventData;
+
+static FileEventData *
+file_event_data_new (GFile *file,
+                    GFileMonitorEvent event_type)
+{
+       FileEventData *fed;
+
+       fed = g_new0 (FileEventData, 1);
+       fed->file = g_object_ref (file);
+       fed->event_type = event_type;
+
+       return fed;
+}
+
 static void
-source_registry_server_monitor_changed_cb (GFileMonitor *monitor,
-                                           GFile *file,
-                                           GFile *other_file,
-                                           GFileMonitorEvent event_type,
-                                           ESourceRegistryServer *server)
+file_event_data_free (gpointer ptr)
 {
-       if (event_type == G_FILE_MONITOR_EVENT_CREATED) {
+       FileEventData *fed = ptr;
+
+       if (fed) {
+               g_clear_object (&fed->file);
+               g_free (fed);
+       }
+}
+
+static void
+source_registry_server_process_file_monitor_event (gpointer key,
+                                                  gpointer value,
+                                                  gpointer user_data)
+{
+       const gchar *uid = key;
+       const FileEventData *fed = value;
+       ESourceRegistryServer *server = user_data;
+       GFileMonitorEvent event_type;
+
+       g_return_if_fail (uid != NULL);
+       g_return_if_fail (fed != NULL);
+
+       event_type = fed->event_type;
+
+       if (e_source_registry_debug_enabled ()) {
+               e_source_registry_debug_print ("Processing file monitor event %s (%u) for UID: %s\n",
+                       event_type == G_FILE_MONITOR_EVENT_CHANGED ? "CHANGED" :
+                       event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT ? "CHANGES_DONE_HINT" :
+                       event_type == G_FILE_MONITOR_EVENT_DELETED ? "DELETED" :
+                       event_type == G_FILE_MONITOR_EVENT_CREATED ? "CREATED" :
+                       event_type == G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED ? "ATTRIBUTE_CHANGED" :
+                       event_type == G_FILE_MONITOR_EVENT_PRE_UNMOUNT ? "PRE_UNMOUNT" :
+                       event_type == G_FILE_MONITOR_EVENT_UNMOUNTED ? "UNMOUNTED" :
+                       event_type == G_FILE_MONITOR_EVENT_MOVED ? "MOVED" : "???",
+                       event_type,
+                       uid);
+       }
+
+       if (event_type == G_FILE_MONITOR_EVENT_CHANGED ||
+           event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT) {
                ESource *source;
                GError *error = NULL;
-               gchar *uid;
 
-               uid = e_server_side_source_uid_from_file (file, NULL);
-               if (!uid)
+               source = e_source_registry_server_ref_source (server, uid);
+
+               /* If the source does not exist, create it; parsing may have
+                * failed when the file was originally created. This can happen
+                * if the file is created (empty), then e-source-registry-server
+                * detects it, then it’s populated and made valid.
+                *
+                * Otherwise, reload the file since it has changed. */
+               if (source == NULL) {
+                       event_type = G_FILE_MONITOR_EVENT_CREATED;
+               } else if (!e_server_side_source_load (E_SERVER_SIDE_SOURCE (source), NULL, &error)) {
+                       g_warning ("Error reloading source ‘%s’: %s", uid, error->message);
+
+                       g_error_free (error);
+                       g_object_unref (source);
+
                        return;
+               }
 
-               source = e_source_registry_server_ref_source (server, uid);
+               g_object_unref (source);
+       }
 
-               g_free (uid);
+       if (event_type == G_FILE_MONITOR_EVENT_CREATED) {
+               ESource *source;
+               GError *error = NULL;
+
+               source = e_source_registry_server_ref_source (server, uid);
 
                if (!source) {
                        /* it can return NULL source for hidden files */
-                       source = e_server_side_source_new (server, file, &error);
+                       source = e_server_side_source_new (server, fed->file, &error);
                }
 
                if (!error && source) {
                        /* File monitors are only placed on directories
                         * where data sources are writable and removable,
                         * so it should be safe to assume these flags. */
-                       e_server_side_source_set_writable (
-                               E_SERVER_SIDE_SOURCE (source), TRUE);
-                       e_server_side_source_set_removable (
-                               E_SERVER_SIDE_SOURCE (source), TRUE);
+                       e_server_side_source_set_writable (E_SERVER_SIDE_SOURCE (source), TRUE);
+                       e_server_side_source_set_removable (E_SERVER_SIDE_SOURCE (source), TRUE);
 
                        e_source_registry_server_add_source (server, source);
                } else if (error) {
-                       e_source_registry_server_load_error (
-                               server, file, error);
+                       e_source_registry_server_load_error (server, fed->file, error);
                        g_error_free (error);
                }
 
@@ -460,17 +532,9 @@ source_registry_server_monitor_changed_cb (GFileMonitor *monitor,
 
        if (event_type == G_FILE_MONITOR_EVENT_DELETED) {
                ESource *source;
-               gchar *uid;
-
-               uid = e_server_side_source_uid_from_file (file, NULL);
-
-               if (uid == NULL)
-                       return;
 
                source = e_source_registry_server_ref_source (server, uid);
 
-               g_free (uid);
-
                if (source == NULL)
                        return;
 
@@ -485,6 +549,87 @@ source_registry_server_monitor_changed_cb (GFileMonitor *monitor,
 }
 
 static gboolean
+source_registry_server_process_file_monitor_events_cb (gpointer user_data)
+{
+       ESourceRegistryServer *server = user_data;
+       GHashTable *events;
+
+       if (g_source_is_destroyed (g_main_current_source ()))
+               return FALSE;
+
+       g_return_val_if_fail (E_IS_SOURCE_REGISTRY_SERVER (server), FALSE);
+
+       g_mutex_lock (&server->priv->file_monitor_lock);
+       events = server->priv->file_monitor_events;
+       server->priv->file_monitor_events = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, 
file_event_data_free);
+       g_mutex_unlock (&server->priv->file_monitor_lock);
+
+       g_hash_table_foreach (events, source_registry_server_process_file_monitor_event, server);
+       g_hash_table_destroy (events);
+
+       return FALSE;
+}
+
+static void
+source_registry_server_monitor_changed_cb (GFileMonitor *monitor,
+                                           GFile *file,
+                                           GFile *other_file,
+                                           GFileMonitorEvent event_type,
+                                           ESourceRegistryServer *server)
+{
+       if (e_source_registry_debug_enabled ()) {
+               gchar *uri;
+
+               uri = g_file_get_uri (file);
+               e_source_registry_debug_print ("Handling file monitor event %s (%u) for URI: %s\n",
+                       event_type == G_FILE_MONITOR_EVENT_CHANGED ? "CHANGED" :
+                       event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT ? "CHANGES_DONE_HINT" :
+                       event_type == G_FILE_MONITOR_EVENT_DELETED ? "DELETED" :
+                       event_type == G_FILE_MONITOR_EVENT_CREATED ? "CREATED" :
+                       event_type == G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED ? "ATTRIBUTE_CHANGED" :
+                       event_type == G_FILE_MONITOR_EVENT_PRE_UNMOUNT ? "PRE_UNMOUNT" :
+                       event_type == G_FILE_MONITOR_EVENT_UNMOUNTED ? "UNMOUNTED" :
+                       event_type == G_FILE_MONITOR_EVENT_MOVED ? "MOVED" : "???",
+                       event_type,
+                       uri);
+               g_free (uri);
+       }
+
+       if (event_type == G_FILE_MONITOR_EVENT_CHANGED ||
+           event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT ||
+           event_type == G_FILE_MONITOR_EVENT_CREATED ||
+           event_type == G_FILE_MONITOR_EVENT_DELETED) {
+               gchar *uid;
+
+               uid = e_server_side_source_uid_from_file (file, NULL);
+
+               if (uid == NULL)
+                       return;
+
+               g_mutex_lock (&server->priv->file_monitor_lock);
+               /* This overwrites any previous events, aka the last wins
+                  (overwrite can be DELETE + CREATE, which handles it correctly). */
+               g_hash_table_insert (server->priv->file_monitor_events, uid, file_event_data_new (file, 
event_type));
+
+               if (server->priv->file_monitor_source) {
+                       g_source_destroy (server->priv->file_monitor_source);
+                       g_source_unref (server->priv->file_monitor_source);
+               }
+
+               server->priv->file_monitor_source = g_timeout_source_new_seconds (3);
+               g_source_set_callback (
+                       server->priv->file_monitor_source,
+                       source_registry_server_process_file_monitor_events_cb,
+                       server, NULL);
+               g_source_attach (
+                       server->priv->file_monitor_source,
+                       server->priv->main_context);
+
+               g_mutex_unlock (&server->priv->file_monitor_lock);
+       }
+}
+
+static gboolean
 source_registry_server_traverse_cb (GNode *node,
                                     GQueue *queue)
 {
@@ -587,6 +732,14 @@ source_registry_server_dispose (GObject *object)
 
        priv = E_SOURCE_REGISTRY_SERVER_GET_PRIVATE (object);
 
+       g_mutex_lock (&priv->file_monitor_lock);
+       if (priv->file_monitor_source) {
+               g_source_destroy (priv->file_monitor_source);
+               g_source_unref (priv->file_monitor_source);
+               priv->file_monitor_source = NULL;
+       }
+       g_mutex_unlock (&priv->file_monitor_lock);
+
        if (priv->main_context != NULL) {
                g_main_context_unref (priv->main_context);
                priv->main_context = NULL;
@@ -599,6 +752,7 @@ source_registry_server_dispose (GObject *object)
        g_hash_table_remove_all (priv->sources);
        g_hash_table_remove_all (priv->orphans);
        g_hash_table_remove_all (priv->monitors);
+       g_hash_table_remove_all (priv->file_monitor_events);
 
        /* Chain up to parent's dispose() method. */
        G_OBJECT_CLASS (e_source_registry_server_parent_class)->
@@ -615,9 +769,11 @@ source_registry_server_finalize (GObject *object)
        g_hash_table_destroy (priv->sources);
        g_hash_table_destroy (priv->orphans);
        g_hash_table_destroy (priv->monitors);
+       g_hash_table_destroy (priv->file_monitor_events);
 
        g_mutex_clear (&priv->sources_lock);
        g_mutex_clear (&priv->orphans_lock);
+       g_mutex_clear (&priv->file_monitor_lock);
 
        /* Chain up to parent's finalize() method. */
        G_OBJECT_CLASS (e_source_registry_server_parent_class)->
@@ -966,6 +1122,10 @@ e_source_registry_server_init (ESourceRegistryServer *server)
        server->priv->monitors = monitors;
        g_mutex_init (&server->priv->sources_lock);
        g_mutex_init (&server->priv->orphans_lock);
+       g_mutex_init (&server->priv->file_monitor_lock);
+
+       server->priv->file_monitor_source = NULL;
+       server->priv->file_monitor_events = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, 
file_event_data_free);
 
        g_signal_connect (
                source_manager, "handle-create-sources",