[gnome-photos] item-manager: Separate out URN change detection due to file updates

[Debarshi Ray <debarshir src gnome org>]

commit 04e878dd30602dcdc5e16a56918c9914d197411e
Author: Debarshi Ray <debarshir gnome org>
Date:   Wed Feb 7 00:10:18 2018 +0100

    item-manager: Separate out URN change detection due to file updates
    
    Detection of URN changes due to atomic file updates is hinged on the
    URI. The query can be as relaxed as possible, since ultimately the URI
    will be checked.
    
    Currently, the code that handles additions to Tracker's database tries
    to detect the relevance of the addition for all modes through a single
    query. It is, at best, quite hard to get right with a single query.
    Therefore, going forward, they should be separated out into multiple
    queries, with each query targetting one specific mode or purpose. This
    is a step in that direction.

 src/photos-item-manager.c | 60 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 52 insertions(+), 8 deletions(-)
---
diff --git a/src/photos-item-manager.c b/src/photos-item-manager.c
index 0f7506de..fd163bd1 100644
--- a/src/photos-item-manager.c
+++ b/src/photos-item-manager.c
@@ -371,16 +371,16 @@ photos_item_manager_check_wait_for_changes (PhotosItemManager *self, const gchar
 
 
 static void
-photos_item_manager_item_created_executed (GObject *source_object, GAsyncResult *res, gpointer user_data)
+photos_item_manager_item_created_executed_overview (GObject *source_object, GAsyncResult *res, gpointer 
user_data)
 {
   g_autoptr (PhotosItemManager) self = PHOTOS_ITEM_MANAGER (user_data);
-  PhotosSingleItemJob *job = PHOTOS_SINGLE_ITEM_JOB (source_object);
+  PhotosSingleItemJob *job_overview = PHOTOS_SINGLE_ITEM_JOB (source_object);
   TrackerSparqlCursor *cursor = NULL; /* TODO: use g_autoptr */
 
   {
     g_autoptr (GError) error = NULL;
 
-    cursor = photos_single_item_job_finish (job, res, &error);
+    cursor = photos_single_item_job_finish (job_overview, res, &error);
     if (error != NULL)
       {
         g_warning ("Unable to query single item: %s", error->message);
@@ -393,6 +393,34 @@ photos_item_manager_item_created_executed (GObject *source_object, GAsyncResult
 
   photos_item_manager_add_item (self, cursor, FALSE);
 
+ out:
+  g_clear_object (&cursor);
+}
+
+
+static void
+photos_item_manager_item_created_executed_wait_for_changes (GObject *source_object,
+                                                            GAsyncResult *res,
+                                                            gpointer user_data)
+{
+  g_autoptr (PhotosItemManager) self = PHOTOS_ITEM_MANAGER (user_data);
+  PhotosSingleItemJob *job_wait_for_changes = PHOTOS_SINGLE_ITEM_JOB (source_object);
+  TrackerSparqlCursor *cursor = NULL; /* TODO: use g_autoptr */
+
+  {
+    g_autoptr (GError) error = NULL;
+
+    cursor = photos_single_item_job_finish (job_wait_for_changes, res, &error);
+    if (error != NULL)
+      {
+        g_warning ("Unable to query single item: %s", error->message);
+        goto out;
+      }
+  }
+
+  if (cursor == NULL)
+    goto out;
+
   if (!photos_item_manager_cursor_is_collection (cursor))
     {
       const gchar *id;
@@ -400,7 +428,8 @@ photos_item_manager_item_created_executed (GObject *source_object, GAsyncResult
 
       id = tracker_sparql_cursor_get_string (cursor, PHOTOS_QUERY_COLUMNS_URN, NULL);
       uri = tracker_sparql_cursor_get_string (cursor, PHOTOS_QUERY_COLUMNS_URI, NULL);
-      photos_item_manager_check_wait_for_changes (self, id, uri);
+      if (id != NULL && id[0] != '\0' && uri != NULL && uri[0] != '\0')
+        photos_item_manager_check_wait_for_changes (self, id, uri);
     }
 
  out:
@@ -414,7 +443,8 @@ photos_item_manager_item_created (PhotosItemManager *self, const gchar *urn)
   GApplication *app;
   PhotosItemManagerHiddenItem *old_hidden_item;
   PhotosSearchContextState *state;
-  g_autoptr (PhotosSingleItemJob) job = NULL;
+  g_autoptr (PhotosSingleItemJob) job_overview = NULL;
+  guint wait_for_changes_size;
 
   old_hidden_item = (PhotosItemManagerHiddenItem *) g_hash_table_lookup (self->hidden_items, urn);
   g_return_if_fail (old_hidden_item == NULL);
@@ -422,13 +452,27 @@ photos_item_manager_item_created (PhotosItemManager *self, const gchar *urn)
   app = g_application_get_default ();
   state = photos_search_context_get_state (PHOTOS_SEARCH_CONTEXT (app));
 
-  job = photos_single_item_job_new (urn);
-  photos_single_item_job_run (job,
+  job_overview = photos_single_item_job_new (urn);
+  photos_single_item_job_run (job_overview,
                               state,
                               PHOTOS_QUERY_FLAGS_NONE,
                               NULL,
-                              photos_item_manager_item_created_executed,
+                              photos_item_manager_item_created_executed_overview,
                               g_object_ref (self));
+
+  wait_for_changes_size = g_hash_table_size (self->wait_for_changes_table);
+  if (wait_for_changes_size > 0)
+    {
+      g_autoptr (PhotosSingleItemJob) job_wait_for_changes = NULL;
+
+      job_wait_for_changes = photos_single_item_job_new (urn);
+      photos_single_item_job_run (job_wait_for_changes,
+                                  state,
+                                  PHOTOS_QUERY_FLAGS_UNFILTERED,
+                                  NULL,
+                                  photos_item_manager_item_created_executed_wait_for_changes,
+                                  g_object_ref (self));
+    }
 }