basesink: make it easy to override the pad query

Add a vmethod to handle the pad query.
Install a default handler for the pad query.
Use the new query function in filesink

libs/gst/base/gstbasesink.c

@@ -366,7 +366,7 @@ static void gst_base_sink_get_property (GObject * object, guint prop_id,
 
 static gboolean gst_base_sink_send_event (GstElement * element,
     GstEvent * event);
-static gboolean gst_base_sink_query (GstElement * element, GstQuery * query);
+static gboolean default_element_query (GstElement * element, GstQuery * query);
 static const GstQueryType *gst_base_sink_get_query_types (GstElement * element);
 
 static GstCaps *gst_base_sink_get_caps (GstBaseSink * sink);
@@ -387,6 +387,7 @@ static gboolean gst_base_sink_default_prepare_seek_segment (GstBaseSink * sink,
 static GstStateChangeReturn gst_base_sink_change_state (GstElement * element,
     GstStateChange transition);
 
+static gboolean gst_base_sink_sink_query (GstPad * pad, GstQuery * query);
 static GstFlowReturn gst_base_sink_chain (GstPad * pad, GstBuffer * buffer);
 static GstFlowReturn gst_base_sink_chain_list (GstPad * pad,
     GstBufferList * list);
@@ -397,6 +398,8 @@ static gboolean gst_base_sink_pad_activate_push (GstPad * pad, gboolean active);
 static gboolean gst_base_sink_pad_activate_pull (GstPad * pad, gboolean active);
 static gboolean gst_base_sink_event (GstPad * pad, GstEvent * event);
 
+static gboolean default_sink_query (GstBaseSink * sink, GstQuery * query);
+
 static gboolean gst_base_sink_negotiate_pull (GstBaseSink * basesink);
 static GstCaps *gst_base_sink_pad_getcaps (GstPad * pad);
 static gboolean gst_base_sink_pad_setcaps (GstPad * pad, GstCaps * caps);
@@ -552,7 +555,7 @@ gst_base_sink_class_init (GstBaseSinkClass * klass)
   gstelement_class->change_state =
       GST_DEBUG_FUNCPTR (gst_base_sink_change_state);
   gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_base_sink_send_event);
-  gstelement_class->query = GST_DEBUG_FUNCPTR (gst_base_sink_query);
+  gstelement_class->query = GST_DEBUG_FUNCPTR (default_element_query);
   gstelement_class->get_query_types =
       GST_DEBUG_FUNCPTR (gst_base_sink_get_query_types);
 
@@ -562,6 +565,7 @@ gst_base_sink_class_init (GstBaseSinkClass * klass)
   klass->get_times = GST_DEBUG_FUNCPTR (gst_base_sink_get_times);
   klass->activate_pull =
       GST_DEBUG_FUNCPTR (gst_base_sink_default_activate_pull);
+  klass->query = GST_DEBUG_FUNCPTR (default_sink_query);
 
   /* Registering debug symbols for function pointers */
   GST_DEBUG_REGISTER_FUNCPTR (gst_base_sink_pad_getcaps);
@@ -693,6 +697,7 @@ gst_base_sink_init (GstBaseSink * basesink, gpointer g_class)
       gst_base_sink_pad_activate_push);
   gst_pad_set_activatepull_function (basesink->sinkpad,
       gst_base_sink_pad_activate_pull);
+  gst_pad_set_query_function (basesink->sinkpad, gst_base_sink_sink_query);
   gst_pad_set_event_function (basesink->sinkpad, gst_base_sink_event);
   gst_pad_set_chain_function (basesink->sinkpad, gst_base_sink_chain);
   gst_pad_set_chain_list_function (basesink->sinkpad, gst_base_sink_chain_list);
@@ -4819,7 +4824,7 @@ gst_base_sink_get_query_types (GstElement * element)
 }
 
 static gboolean
-gst_base_sink_query (GstElement * element, GstQuery * query)
+default_element_query (GstElement * element, GstQuery * query)
 {
   gboolean res = FALSE;
 
@@ -4944,6 +4949,37 @@ gst_base_sink_query (GstElement * element, GstQuery * query)
   return res;
 }
 
+static gboolean
+default_sink_query (GstBaseSink * basesink, GstQuery * query)
+{
+  return gst_pad_query_default (basesink->sinkpad, query);
+}
+
+static gboolean
+gst_base_sink_sink_query (GstPad * pad, GstQuery * query)
+{
+  GstBaseSink *basesink;
+  GstBaseSinkClass *bclass;
+  gboolean res;
+
+  basesink = GST_BASE_SINK_CAST (gst_pad_get_parent (pad));
+  if (G_UNLIKELY (basesink == NULL)) {
+    gst_query_unref (query);
+    return FALSE;
+  }
+
+  bclass = GST_BASE_SINK_GET_CLASS (basesink);
+
+  if (bclass->query)
+    res = bclass->query (basesink, query);
+  else
+    res = FALSE;
+
+  gst_object_unref (basesink);
+
+  return res;
+}
+
 static GstStateChangeReturn
 gst_base_sink_change_state (GstElement * element, GstStateChange transition)
 {

libs/gst/base/gstbasesink.h

@@ -133,6 +133,7 @@ struct _GstBaseSink {
  * @fixate: Only useful in pull mode, this vmethod will be called in response to
  *     gst_pad_fixate_caps() being called on the sink pad. Implement if you have
  *     ideas about what should be the default values for the caps you support.
+ * @query: perform a #GstQuery on the element. Since: 0.10.36
  *
  * Subclasses can override any of the available virtual methods or not, as
  * needed. At the minimum, the @render method should be overridden to
@@ -186,8 +187,11 @@ struct _GstBaseSinkClass {
   /* Render a BufferList */
   GstFlowReturn (*render_list)  (GstBaseSink *sink, GstBufferList *buffer_list);
 
+  /* notify subclass of query */
+  gboolean      (*query)        (GstBaseSink *sink, GstQuery *query);
+
   /*< private >*/
-  gpointer       _gst_reserved[GST_PADDING_LARGE-5];
+  gpointer       _gst_reserved[GST_PADDING_LARGE-6];
 };
 
 GType gst_base_sink_get_type(void);

plugins/elements/gstfilesink.c

@@ -168,7 +168,7 @@ static gboolean gst_file_sink_do_seek (GstFileSink * filesink,
 static gboolean gst_file_sink_get_current_offset (GstFileSink * filesink,
     guint64 * p_pos);
 
-static gboolean gst_file_sink_query (GstPad * pad, GstQuery * query);
+static gboolean gst_file_sink_query (GstBaseSink * bsink, GstQuery * query);
 
 static void gst_file_sink_uri_handler_init (gpointer g_iface,
     gpointer iface_data);
@@ -246,6 +246,7 @@ gst_file_sink_class_init (GstFileSinkClass * klass)
 
   gstbasesink_class->start = GST_DEBUG_FUNCPTR (gst_file_sink_start);
   gstbasesink_class->stop = GST_DEBUG_FUNCPTR (gst_file_sink_stop);
+  gstbasesink_class->query = GST_DEBUG_FUNCPTR (gst_file_sink_query);
   gstbasesink_class->render = GST_DEBUG_FUNCPTR (gst_file_sink_render);
   gstbasesink_class->event = GST_DEBUG_FUNCPTR (gst_file_sink_event);
 
@@ -258,12 +259,6 @@ gst_file_sink_class_init (GstFileSinkClass * klass)
 static void
 gst_file_sink_init (GstFileSink * filesink, GstFileSinkClass * g_class)
 {
-  GstPad *pad;
-
-  pad = GST_BASE_SINK_PAD (filesink);
-
-  gst_pad_set_query_function (pad, GST_DEBUG_FUNCPTR (gst_file_sink_query));
-
   filesink->filename = NULL;
   filesink->file = NULL;
   filesink->buffer_mode = DEFAULT_BUFFER_MODE;
@@ -466,36 +461,45 @@ close_failed:
 }
 
 static gboolean
-gst_file_sink_query (GstPad * pad, GstQuery * query)
+gst_file_sink_query (GstBaseSink * bsink, GstQuery * query)
 {
+  gboolean res;
   GstFileSink *self;
   GstFormat format;
 
-  self = GST_FILE_SINK (GST_PAD_PARENT (pad));
+  self = GST_FILE_SINK (bsink);
 
   switch (GST_QUERY_TYPE (query)) {
     case GST_QUERY_POSITION:
       gst_query_parse_position (query, &format, NULL);
+
       switch (format) {
         case GST_FORMAT_DEFAULT:
         case GST_FORMAT_BYTES:
           gst_query_set_position (query, GST_FORMAT_BYTES, self->current_pos);
-          return TRUE;
+          res = TRUE;
+          break;
         default:
-          return FALSE;
+          res = FALSE;
+          break;
       }
+      break;
 
     case GST_QUERY_FORMATS:
       gst_query_set_formats (query, 2, GST_FORMAT_DEFAULT, GST_FORMAT_BYTES);
-      return TRUE;
+      res = TRUE;
+      break;
 
     case GST_QUERY_URI:
       gst_query_set_uri (query, self->uri);
-      return TRUE;
+      res = TRUE;
+      break;
 
     default:
-      return gst_pad_query_default (pad, query);
+      res = GST_BASE_SINK_CLASS (parent_class)->query (bsink, query);
+      break;
   }
+  return res;
 }
 
 #ifdef HAVE_FSEEKO