[tracker/wip/removable-device-completed: 4/11] libtracker-miner: Avoid processing item queue while it is blocked

[Sam Thursfield <sthursfield src gnome org>]

commit f1a75073db939ca88ddaba2e7b16280ea68bbf21
Author: Sam Thursfield <sam thursfield codethink co uk>
Date:   Thu Jun 14 17:52:15 2012 +0100

    libtracker-miner: Avoid processing item queue while it is blocked
    
    item_add_or_update_cb() had a call to item_queue_handlers_set_up().
    This was unneccessary as the queue will already be running, except in
    one the following cases:
     -  the extraction or SPARQL task pools are full
     - the queue is blocked waiting for a specific file to process
     - the queue is empty
    
    Previously, while waiting for a file to process we might pop and
    reenqueue the next file in the queue several times, which is a waste of
    effort and makes it difficult to detect if the miner is stuck in an
    infinite loop.

 src/libtracker-miner/tracker-miner-fs.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)
---
diff --git a/src/libtracker-miner/tracker-miner-fs.c b/src/libtracker-miner/tracker-miner-fs.c
index 45e1d06..8cbf160 100644
--- a/src/libtracker-miner/tracker-miner-fs.c
+++ b/src/libtracker-miner/tracker-miner-fs.c
@@ -165,6 +165,7 @@ struct _TrackerMinerFSPrivate {
 	GTimer         *extraction_timer;
 
 	guint           item_queues_handler_id;
+	gboolean        item_queue_blocked;
 
 	gdouble         throttle;
 
@@ -1194,9 +1195,15 @@ item_add_or_update_cb (TrackerMinerFS *fs,
 		                            ctxt->priority,
 		                            sparql_buffer_task_finished_cb,
 		                            fs);
+
+		if (fs->priv->item_queue_blocked == TRUE) {
+			tracker_sparql_buffer_flush (fs->priv->sparql_buffer, "Queue handlers WAIT");
+		}
 	}
 
-	if (!tracker_task_pool_limit_reached (TRACKER_TASK_POOL (fs->priv->sparql_buffer))) {
+	if (tracker_miner_fs_has_items_to_process (fs) == FALSE &&
+	    tracker_task_pool_get_size (TRACKER_TASK_POOL (fs->priv->task_pool)) == 0) {
+		/* We need to run this one more time to trigger process_stop() */
 		item_queue_handlers_set_up (fs);
 	}
 
@@ -2028,9 +2035,12 @@ item_queue_handlers_cb (gpointer user_data)
 		 * on with the queues... */
 		tracker_sparql_buffer_flush (fs->priv->sparql_buffer,
 		                             "Queue handlers WAIT");
+		fs->priv->item_queue_blocked = TRUE;
 		return FALSE;
 	}
 
+	fs->priv->item_queue_blocked = FALSE;
+
 	if (file && queue != QUEUE_DELETED &&
 	    tracker_file_is_locked (file)) {
 		gchar *uri;