[gtk-vnc] Batch up incoming audio samples for upto 100ms

[Daniel P. Berrange <dberrange src gnome org>]

commit 4e1598416527e85bf4b7eae33aaebf2f4e7964f8
Author: Daniel P. Berrange <berrange redhat com>
Date:   Fri Dec 9 16:27:14 2011 +0000

    Batch up incoming audio samples for upto 100ms
    
    The length of samples received from the guest can be very
    small (as little as 1 sample). If this is dispatched directly
    to the audio sink this can cause excessive CPU consumption
    and context switching. Batch up incoming data for upto 100ms
    until dispatching it

 src/vncconnection.c |   46 +++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 39 insertions(+), 7 deletions(-)
---
diff --git a/src/vncconnection.c b/src/vncconnection.c
index aea507e..ebfcc27 100644
--- a/src/vncconnection.c
+++ b/src/vncconnection.c
@@ -2857,6 +2857,26 @@ static gboolean vnc_connection_framebuffer_update(VncConnection *conn, gint32 et
 }
 
 
+static gboolean vnc_connection_audio_timer(gpointer opaque)
+{
+	VncConnection *conn = opaque;
+	VncConnectionPrivate *priv = conn->priv;
+
+	priv->audio_timer = 0;
+	if (!priv->audio_sample)
+		return FALSE;
+
+	VNC_DEBUG("Audio tick %u\n", priv->audio_sample->length);
+
+	if (priv->audio)
+		vnc_audio_playback_data(priv->audio, priv->audio_sample);
+
+	vnc_audio_sample_free(priv->audio_sample);
+	priv->audio_sample = NULL;
+	return FALSE;
+}
+
+
 struct audio_action_data
 {
 	VncConnection *conn;
@@ -3046,16 +3066,28 @@ static gboolean vnc_connection_server_message(VncConnection *conn)
 					priv->has_error = TRUE;
 					break;
 				}
-				priv->audio_sample = vnc_audio_sample_new(n_length);
+				if (priv->audio_sample &&
+				    ((priv->audio_sample->capacity - priv->audio_sample->length) < n_length)) {
+					g_source_remove(priv->audio_timer);
+					fprintf(stderr, "%u %u %u\n",
+						priv->audio_sample->capacity,
+						priv->audio_sample->length,
+						n_length);
+					vnc_connection_audio_action(conn, 2);
+					vnc_audio_sample_free(priv->audio_sample);
+					priv->audio_sample = NULL;
+				}
+				if (!priv->audio_sample) {
+					priv->audio_sample = vnc_audio_sample_new(1024*1024);
+					priv->audio_timer = g_timeout_add(50,
+									  vnc_connection_audio_timer,
+									  conn);
+				}
+
 				vnc_connection_read(conn,
-						    priv->audio_sample->data,
+						    priv->audio_sample->data + priv->audio_sample->length,
 						    n_length);
 				priv->audio_sample->length += n_length;
-
-				vnc_connection_audio_action(conn, 2);
-
-				vnc_audio_sample_free(priv->audio_sample);
-				priv->audio_sample = NULL;
 				break;
 			case 1:
 				if (priv->audio)