[tracker/tracker-0.10] libtracker-miner: perform task merging for monitor events

[Martyn James Russell <mr src gnome org>]

commit 206c30b2dffa30eb47c86eca102687c53eabe548
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri May 13 15:56:25 2011 +0200

    libtracker-miner: perform task merging for monitor events
    
    This only kicks in after initial crawling, and makes most sense
    in paused miners, so consecutive, longer term monitor events
    are merged together with previous unhandled events to avoid
    useless operations after resuming.

 src/libtracker-miner/tracker-miner-fs.c |  175 +++++++++++++++++++++++++++++--
 1 files changed, 164 insertions(+), 11 deletions(-)
---
diff --git a/src/libtracker-miner/tracker-miner-fs.c b/src/libtracker-miner/tracker-miner-fs.c
index df2a9e8..98bf6a9 100644
--- a/src/libtracker-miner/tracker-miner-fs.c
+++ b/src/libtracker-miner/tracker-miner-fs.c
@@ -3215,6 +3215,150 @@ should_process_file (TrackerMinerFS *fs,
 	return should_change_index_for_file (fs, file);
 }
 
+static gint
+compare_files (gconstpointer a,
+	       gconstpointer b)
+{
+	if (g_file_equal (G_FILE (a), G_FILE (b))) {
+		return 0;
+	}
+
+	return 1;
+}
+
+static gint
+compare_moved_files (gconstpointer a,
+                     gconstpointer b)
+{
+	const ItemMovedData *data = a;
+	GFile *file = G_FILE (b);
+
+	/* Compare with dest file */
+	if (g_file_equal (data->file, file)) {
+		return 0;
+	}
+
+	return 1;
+}
+
+/* Checks previous created/updated/deleted/moved queues for
+ * monitor events. Returns TRUE if the item should still
+ * be added to the queue.
+ */
+static gboolean
+check_item_queues (TrackerMinerFS *fs,
+		   QueueState      queue,
+		   GFile          *file,
+		   GFile          *other_file)
+{
+	GList *elem;
+
+	if (!fs->private->been_crawled) {
+		/* Only do this after initial crawling, so
+		 * we are mostly sure that we won't be doing
+		 * checks on huge lists.
+		 */
+		return TRUE;
+	}
+
+	switch (queue) {
+	case QUEUE_CREATED:
+		/* Created items aren't likely to have
+		 * anything in other queues for the same
+		 * file.
+		 */
+		return TRUE;
+	case QUEUE_UPDATED:
+		/* No further updates after a previous created/updated event */
+		if (g_queue_find_custom (fs->private->items_created, file, compare_files) ||
+		    g_queue_find_custom (fs->private->items_updated, file, compare_files)) {
+			g_debug ("  Found previous unhandled CREATED/UPDATED event");
+			return FALSE;
+		}
+
+		return TRUE;
+	case QUEUE_DELETED:
+		elem = g_queue_find_custom (fs->private->items_updated, file, compare_files);
+
+		if (elem) {
+			/* Remove all previous updates */
+			g_debug ("  Deleting previous unhandled UPDATED event");
+			g_object_unref (elem->data);
+			g_queue_delete_link (fs->private->items_updated, elem);
+		}
+
+		elem = g_queue_find_custom (fs->private->items_created, file, compare_files);
+
+		if (elem) {
+			/* Created event still in the queue,
+			 * remove it and ignore the current event
+			 */
+			g_debug ("  Found matching unhandled CREATED event, removing file altogether");
+			g_object_unref (elem->data);
+			g_queue_delete_link (fs->private->items_created, elem);
+			return FALSE;
+		}
+
+		return TRUE;
+	case QUEUE_MOVED:
+		/* Kill any events on other_file (The dest one), since it will be rewritten anyway */
+		elem = g_queue_find_custom (fs->private->items_created, other_file, compare_files);
+
+		if (elem) {
+			g_debug ("  Removing previous unhandled CREATED event for dest file, will be rewritten anyway");
+			g_object_unref (elem->data);
+			g_queue_delete_link (fs->private->items_created, elem);
+		}
+
+		elem = g_queue_find_custom (fs->private->items_updated, other_file, compare_files);
+
+		if (elem) {
+			g_debug ("  Removing previous unhandled UPDATED event for dest file, will be rewritten anyway");
+			g_object_unref (elem->data);
+			g_queue_delete_link (fs->private->items_updated, elem);
+		}
+
+		/* Now check file (Origin one) */
+		elem = g_queue_find_custom (fs->private->items_created, file, compare_files);
+
+		if (elem) {
+			/* If source file was created, replace the
+			 * GFile there, we assume all posterior updates
+			 * have been merged together previously by this
+			 * same function.
+			 */
+			g_debug ("  Found matching unhandled CREATED event "
+			         "for source file, merging both events together");
+			g_object_unref (elem->data);
+			elem->data = g_object_ref (other_file);
+
+			return FALSE;
+		}
+
+		elem = g_queue_find_custom (fs->private->items_moved, file, compare_moved_files);
+
+		if (elem) {
+			ItemMovedData *data = elem->data;
+
+			/* Origin file was the dest of a previous
+			 * move operation, merge these together.
+			 */
+			g_debug ("  Source file is the destination of a previous "
+			         "unhandled MOVED event, merging both events together");
+			g_object_unref (data->file);
+			data->file = g_object_ref (other_file);
+			return FALSE;
+		}
+
+		return TRUE;
+		break;
+	default:
+		g_assert_not_reached ();
+	}
+
+	return TRUE;
+}
+
 static void
 monitor_item_created_cb (TrackerMonitor *monitor,
                          GFile          *file,
@@ -3271,7 +3415,8 @@ monitor_item_updated_cb (TrackerMonitor *monitor,
 	         uri,
 	         is_directory ? "DIR" : "FILE");
 
-	if (should_process) {
+	if (should_process &&
+	    check_item_queues (fs, QUEUE_UPDATED, file, NULL)) {
 		trace_eq_push_tail ("UPDATED", file, "On monitor event");
 		g_queue_push_tail (fs->private->items_updated,
 		                   g_object_ref (file));
@@ -3302,12 +3447,14 @@ monitor_item_attribute_updated_cb (TrackerMonitor *monitor,
 	         uri,
 	         is_directory ? "DIR" : "FILE");
 
-	if (should_process) {
+	if (should_process &&
+	    check_item_queues (fs, QUEUE_UPDATED, file, NULL)) {
 		/* Set the Quark specifying that ONLY attributes were
 		 * modified */
 		g_object_set_qdata (G_OBJECT (file),
 		                    fs->private->quark_attribute_updated,
 		                    GINT_TO_POINTER (TRUE));
+
 		trace_eq_push_tail ("UPDATED", file, "On monitor event (attributes)");
 		g_queue_push_tail (fs->private->items_updated,
 		                   g_object_ref (file));
@@ -3338,7 +3485,8 @@ monitor_item_deleted_cb (TrackerMonitor *monitor,
 	         uri,
 	         is_directory ? "DIR" : "FILE");
 
-	if (should_process) {
+	if (should_process &&
+	    check_item_queues (fs, QUEUE_DELETED, file, NULL)) {
 		trace_eq_push_tail ("DELETED", file, "On monitor event");
 		g_queue_push_tail (fs->private->items_deleted,
 		                   g_object_ref (file));
@@ -3453,10 +3601,12 @@ monitor_item_moved_cb (TrackerMonitor *monitor,
 			}
 
 			/* Delete old file */
-			trace_eq_push_tail ("DELETED", file, "On move monitor event");
-			g_queue_push_tail (fs->private->items_deleted,
-			                   g_object_ref (file));
-			item_queue_handlers_set_up (fs);
+			if (check_item_queues (fs, QUEUE_DELETED, file, NULL)) {
+				trace_eq_push_tail ("DELETED", file, "On move monitor event");
+				g_queue_push_tail (fs->private->items_deleted,
+						   g_object_ref (file));
+				item_queue_handlers_set_up (fs);
+			}
 		} else {
 			/* Move monitors to the new place */
 			if (is_directory) {
@@ -3464,11 +3614,14 @@ monitor_item_moved_cb (TrackerMonitor *monitor,
 				                      file,
 				                      other_file);
 			}
+
 			/* Move old file to new file */
-			trace_eq_push_tail_2 ("MOVED", file, other_file, "On monitor event");
-			g_queue_push_tail (fs->private->items_moved,
-			                   item_moved_data_new (other_file, file));
-			item_queue_handlers_set_up (fs);
+			if (check_item_queues (fs, QUEUE_MOVED, file, other_file)) {
+				trace_eq_push_tail_2 ("MOVED", file, other_file, "On monitor event");
+				g_queue_push_tail (fs->private->items_moved,
+				                   item_moved_data_new (other_file, file));
+				item_queue_handlers_set_up (fs);
+			}
 		}
 
 		g_free (other_uri);