[tracker] TrackerExtractDecorator: Fix pause/resume

[Xavier Claessens <xclaesse src gnome org>]

commit 62ed8b54832ed8cb1674f00e097145c7ad4632d0
Author: Xavier Claessens <xavier claessens collabora co uk>
Date:   Mon Feb 3 17:16:15 2014 -0500

    TrackerExtractDecorator: Fix pause/resume
    
    It should not get the next file when the miner is paused/stopped,
    or if there are no items available anymore.
    
    This also ensure we never have more than MAX_EXTRACTING_FILES
    (currently one) extraction operation running in parallel.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=719802

 src/tracker-extract/tracker-extract-decorator.c |   43 +++++++++++++++++++----
 1 files changed, 36 insertions(+), 7 deletions(-)
---
diff --git a/src/tracker-extract/tracker-extract-decorator.c b/src/tracker-extract/tracker-extract-decorator.c
index f79e5cc..abd72c0 100644
--- a/src/tracker-extract/tracker-extract-decorator.c
+++ b/src/tracker-extract/tracker-extract-decorator.c
@@ -28,6 +28,7 @@ enum {
 };
 
 #define TRACKER_EXTRACT_DATA_SOURCE TRACKER_TRACKER_PREFIX "extractor-data-source"
+#define MAX_EXTRACTING_FILES 1
 
 #define TRACKER_EXTRACT_DECORATOR_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), 
TRACKER_TYPE_EXTRACT_DECORATOR, TrackerExtractDecoratorPrivate))
 
@@ -42,6 +43,7 @@ struct _ExtractData {
 struct _TrackerExtractDecoratorPrivate {
        TrackerExtract *extractor;
        GTimer *timer;
+       guint n_extracting_files;
 };
 
 static void decorator_get_next_file (TrackerDecorator *decorator);
@@ -161,9 +163,11 @@ get_metadata_cb (TrackerExtract *extract,
                  GAsyncResult   *result,
                  ExtractData    *data)
 {
+       TrackerExtractDecoratorPrivate *priv;
        TrackerExtractInfo *info;
        GTask *task;
 
+       priv = TRACKER_EXTRACT_DECORATOR (data->decorator)->priv;
        task = tracker_decorator_info_get_task (data->decorator_info);
        info = g_simple_async_result_get_op_res_gpointer (G_SIMPLE_ASYNC_RESULT (result));
 
@@ -179,6 +183,7 @@ get_metadata_cb (TrackerExtract *extract,
                g_task_return_boolean (task, TRUE);
        }
 
+       priv->n_extracting_files--;
        decorator_get_next_file (data->decorator);
 
        tracker_decorator_info_unref (data->decorator_info);
@@ -200,8 +205,8 @@ decorator_next_item_cb (TrackerDecorator *decorator,
        info = tracker_decorator_next_finish (decorator, result, &error);
 
        if (!info) {
-               if (tracker_decorator_get_n_items (decorator) != 0)
-                       g_warning ("Next item could not be retrieved: %s\n", error->message);
+               priv->n_extracting_files--;
+               g_warning ("Next item could not be retrieved: %s\n", error->message);
                g_error_free (error);
                return;
        }
@@ -224,9 +229,24 @@ decorator_next_item_cb (TrackerDecorator *decorator,
 static void
 decorator_get_next_file (TrackerDecorator *decorator)
 {
-       tracker_decorator_next (decorator, NULL,
-                               (GAsyncReadyCallback) decorator_next_item_cb,
-                               NULL);
+       TrackerExtractDecoratorPrivate *priv;
+       guint available_items;
+
+       priv = TRACKER_EXTRACT_DECORATOR (decorator)->priv;
+
+       if (!tracker_miner_is_started (TRACKER_MINER (decorator)) ||
+           tracker_miner_is_paused (TRACKER_MINER (decorator)))
+               return;
+
+       available_items = tracker_decorator_get_n_items (decorator);
+       while (priv->n_extracting_files < MAX_EXTRACTING_FILES &&
+              available_items > 0) {
+               priv->n_extracting_files++;
+               available_items--;
+               tracker_decorator_next (decorator, NULL,
+                                       (GAsyncReadyCallback) decorator_next_item_cb,
+                                       NULL);
+       }
 }
 
 static void
@@ -236,7 +256,9 @@ tracker_extract_decorator_paused (TrackerMiner *miner)
 
        priv = TRACKER_EXTRACT_DECORATOR (miner)->priv;
        g_debug ("Decorator paused\n");
-       g_timer_stop (priv->timer);
+
+       if (priv->timer)
+               g_timer_stop (priv->timer);
 }
 
 static void
@@ -247,7 +269,10 @@ tracker_extract_decorator_resumed (TrackerMiner *miner)
        priv = TRACKER_EXTRACT_DECORATOR (miner)->priv;
        g_debug ("Resuming processing of %d items\n",
                 tracker_decorator_get_n_items (TRACKER_DECORATOR (miner)));
-       g_timer_continue (priv->timer);
+
+       if (priv->timer)
+               g_timer_continue (priv->timer);
+
        decorator_get_next_file (TRACKER_DECORATOR (miner));
 }
 
@@ -259,7 +284,11 @@ tracker_extract_decorator_items_available (TrackerDecorator *decorator)
        priv = TRACKER_EXTRACT_DECORATOR (decorator)->priv;
        g_debug ("Starting processing of %d items\n",
                 tracker_decorator_get_n_items (decorator));
+
        priv->timer = g_timer_new ();
+       if (tracker_miner_is_paused (TRACKER_MINER (decorator)))
+               g_timer_stop (priv->timer);
+
        decorator_get_next_file (decorator);
 }