queue2: fix leak and improve buffering

Keep track of the max requested position and compare this to the write position
in the temp file to get the current amount of buffered data.
Fix memleak of all incomming buffers.

Fixes #588551

gst/playback/gstqueue2.c

@@ -219,6 +219,7 @@ struct _GstQueue
   FILE *temp_file;
   guint64 writing_pos;
   guint64 reading_pos;
+  guint64 max_reading_pos;
   /* we need this to send the first new segment event of the stream
    * because we can't save it on the file */
   gboolean segment_event_received;
@@ -244,7 +245,7 @@ struct _GstQueueClass
                       queue->cur_level.time, \
                       queue->max_level.time, \
                       (guint64) (QUEUE_IS_USING_TEMP_FILE(queue) ? \
-                        queue->writing_pos - queue->reading_pos : \
+                        queue->writing_pos - queue->max_reading_pos : \
                         queue->queue->length))
 
 #define GST_QUEUE_MUTEX_LOCK(q) G_STMT_START {                          \
@@ -871,6 +872,11 @@ gst_queue_write_buffer_to_file (GstQueue * queue, GstBuffer * buffer)
     GST_ERROR_OBJECT (queue, "fwrite returned error");
   }
   queue->writing_pos += size;
+
+  if (queue->writing_pos > queue->max_reading_pos)
+    queue->cur_level.bytes = queue->writing_pos - queue->max_reading_pos;
+  else
+    queue->cur_level.bytes = 0;
 }
 
 /* see if there is enough data in the file to read a full buffer */
@@ -938,6 +944,12 @@ gst_queue_create_read (GstQueue * queue, guint64 offset, guint length,
   *buffer = buf;
 
   queue->reading_pos = offset + length;
+  queue->max_reading_pos = MAX (queue->max_reading_pos, queue->reading_pos);
+
+  if (queue->writing_pos > queue->max_reading_pos)
+    queue->cur_level.bytes = queue->writing_pos - queue->max_reading_pos;
+  else
+    queue->cur_level.bytes = 0;
 
   return GST_FLOW_OK;
 
@@ -1042,6 +1054,7 @@ gst_queue_open_temp_location_file (GstQueue * queue)
 
   queue->writing_pos = 0;
   queue->reading_pos = 0;
+  queue->max_reading_pos = 0;
 
   return TRUE;
 
@@ -1100,6 +1113,7 @@ gst_queue_flush_temp_file (GstQueue * queue)
 
   queue->writing_pos = 0;
   queue->reading_pos = 0;
+  queue->max_reading_pos = 0;
 }
 
 static void
@@ -1143,6 +1157,7 @@ gst_queue_locked_enqueue (GstQueue * queue, gpointer item)
     queue->cur_level.buffers++;
     queue->cur_level.bytes += size;
     queue->bytes_in += size;
+
     /* apply new buffer to segment stats */
     apply_buffer (queue, buffer, &queue->sink_segment);
     /* update the byterate stats */
@@ -1172,7 +1187,10 @@ gst_queue_locked_enqueue (GstQueue * queue, gpointer item)
             goto unexpected_event;
 
           queue->segment_event_received = TRUE;
+          if (queue->starting_segment != NULL)
+            gst_event_unref (queue->starting_segment);
           queue->starting_segment = event;
+          item = NULL;
         }
         /* a new segment allows us to accept more buffers if we got UNEXPECTED
          * from downstream */
@@ -1196,6 +1214,9 @@ gst_queue_locked_enqueue (GstQueue * queue, gpointer item)
 
     if (!QUEUE_IS_USING_TEMP_FILE (queue))
       g_queue_push_tail (queue->queue, item);
+    else
+      gst_mini_object_unref (GST_MINI_OBJECT_CAST (item));
+
     GST_QUEUE_SIGNAL_ADD (queue);
   }
 
@@ -1370,7 +1391,7 @@ gst_queue_is_empty (GstQueue * queue)
     return FALSE;
 
   if (QUEUE_IS_USING_TEMP_FILE (queue)) {
-    return queue->writing_pos == queue->reading_pos;
+    return queue->writing_pos == queue->max_reading_pos;
   } else {
     if (queue->queue->length == 0)
       return TRUE;