alsa: Improve *_list_streams functions

Avoids including useless streams in the list and optimizes GList construction.

2 files changed, 21 insertions, 16 deletions

diff --git a/backends/alsa/alsa-backend.c b/backends/alsa/alsa-backend.c
index 0b7895e..8c4913a 100644
--- a/backends/alsa/alsa-backend.c
+++ b/backends/alsa/alsa-backend.c
@@ -248,23 +248,23 @@ alsa_backend_list_streams (MateMixerBackend *backend)
 
         /* Walk through the list of devices and create the stream list, each
          * device has at most one input and one output stream */
-        list = alsa->priv->devices;
+        list = g_list_last (alsa->priv->devices);
 
         while (list != NULL) {
             AlsaDevice *device = ALSA_DEVICE (list->data);
             AlsaStream *stream;
 
-            stream = alsa_device_get_input_stream (device);
-            if (stream != NULL) {
-                alsa->priv->streams =
-                    g_list_append (alsa->priv->streams, g_object_ref (stream));
-            }
             stream = alsa_device_get_output_stream (device);
-            if (stream != NULL) {
+            if (stream != NULL)
+                alsa->priv->streams =
+                    g_list_prepend (alsa->priv->streams, g_object_ref (stream));
+
+            stream = alsa_device_get_input_stream (device);
+            if (stream != NULL)
                 alsa->priv->streams =
-                    g_list_append (alsa->priv->streams, g_object_ref (stream));
-            }
-            list = list->next;
+                    g_list_prepend (alsa->priv->streams, g_object_ref (stream));
+
+            list = list->prev;
         }
     }
     return alsa->priv->streams;
diff --git a/backends/alsa/alsa-device.c b/backends/alsa/alsa-device.c
index 6a2c54a..643e46e 100644
--- a/backends/alsa/alsa-device.c
+++ b/backends/alsa/alsa-device.c
@@ -465,12 +465,17 @@ alsa_device_list_streams (MateMixerDevice *mmd)
     device = ALSA_DEVICE (mmd);
 
     if (device->priv->streams == NULL) {
-        if (device->priv->output != NULL)
-            device->priv->streams = g_list_prepend (device->priv->streams,
-                                                    g_object_ref (device->priv->output));
-        if (device->priv->input != NULL)
-            device->priv->streams = g_list_prepend (device->priv->streams,
-                                                    g_object_ref (device->priv->input));
+        AlsaStream *stream;
+
+        stream = alsa_device_get_output_stream (device);
+        if (stream != NULL)
+            device->priv->streams =
+                g_list_prepend (device->priv->streams, g_object_ref (stream));
+
+        stream = alsa_device_get_input_stream (device);
+        if (stream != NULL)
+            device->priv->streams =
+                g_list_prepend (device->priv->streams, g_object_ref (stream));
     }
     return device->priv->streams;
 }