gstreamer/plugins/elements/gstqueue.c

/* Gnome-Streamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

//#define DEBUG_ENABLED
//#define STATUS_ENABLED
#ifdef STATUS_ENABLED
#define STATUS(A) DEBUG(A, gst_element_get_name(GST_ELEMENT(queue)))
#else
#define STATUS(A) 
#endif

#include <gstqueue.h>

#include <gst/gstarch.h>

GstElementDetails gst_queue_details = {
  "Queue",
  "Connection",
  "Simple data queue",
  VERSION,
  "Erik Walthinsen <omega@cse.ogi.edu>",
  "(C) 1999",
};


/* Queue signals and args */
enum {
  /* FILL ME */
  LAST_SIGNAL
};

enum {
  ARG_0,
  ARG_LEVEL,
  ARG_MAX_LEVEL,
};


static void gst_queue_class_init(GstQueueClass *klass);
static void gst_queue_init(GstQueue *queue);
static void gst_queue_set_arg(GtkObject *object,GtkArg *arg,guint id);
static void gst_queue_get_arg(GtkObject *object,GtkArg *arg,guint id);

static void gst_queue_push(GstConnection *connection);
static void gst_queue_chain(GstPad *pad,GstBuffer *buf);

static void gst_queue_flush(GstQueue *queue);

static GstElementStateReturn gst_queue_change_state(GstElement *element);

static GstConnectionClass *parent_class = NULL;
//static guint gst_queue_signals[LAST_SIGNAL] = { 0 };

GtkType
gst_queue_get_type(void) {
  static GtkType queue_type = 0;

  if (!queue_type) {
    static const GtkTypeInfo queue_info = {
      "GstQueue",
      sizeof(GstQueue),
      sizeof(GstQueueClass),
      (GtkClassInitFunc)gst_queue_class_init,
      (GtkObjectInitFunc)gst_queue_init,
      (GtkArgSetFunc)gst_queue_set_arg,
      (GtkArgGetFunc)gst_queue_get_arg,
      (GtkClassInitFunc)NULL,
    };
    queue_type = gtk_type_unique(GST_TYPE_CONNECTION,&queue_info);
  }
  return queue_type;
}

static void gst_queue_class_init(GstQueueClass *klass) {
  GtkObjectClass *gtkobject_class;
  GstElementClass *gstelement_class;
  GstConnectionClass *gstconnection_class;

  gtkobject_class = (GtkObjectClass*)klass;
  gstelement_class = (GstElementClass*)klass;
  gstconnection_class = (GstConnectionClass*)klass;

  parent_class = gtk_type_class(GST_TYPE_CONNECTION);

  gtk_object_add_arg_type("GstQueue::level", GTK_TYPE_INT,
                          GTK_ARG_READABLE, ARG_LEVEL);
  gtk_object_add_arg_type("GstQueue::max_level", GTK_TYPE_INT,
                          GTK_ARG_READWRITE, ARG_MAX_LEVEL);

  gstconnection_class->push = gst_queue_push;

  gtkobject_class->set_arg = gst_queue_set_arg;  
  gtkobject_class->get_arg = gst_queue_get_arg;

  gstelement_class->change_state = gst_queue_change_state;
}

static void gst_queue_init(GstQueue *queue) {
  queue->sinkpad = gst_pad_new("sink",GST_PAD_SINK);
  gst_element_add_pad(GST_ELEMENT(queue),queue->sinkpad);
  gst_pad_set_chain_function(queue->sinkpad,gst_queue_chain);

  queue->srcpad = gst_pad_new("src",GST_PAD_SRC);
  gst_element_add_pad(GST_ELEMENT(queue),queue->srcpad);

  queue->queue = NULL;
  queue->level_buffers = 0;
  queue->max_buffers = 20;
  queue->level_bytes = 0;
  queue->size_buffers = 0;
  queue->size_bytes = 0;

  queue->emptylock = g_mutex_new();
  queue->emptycond = g_cond_new();

  queue->fulllock = g_mutex_new();
  queue->fullcond = g_cond_new();
}

GstElement *gst_queue_new(gchar *name) {
  GstElement *queue = GST_ELEMENT(gtk_type_new(GST_TYPE_QUEUE));
  gst_element_set_name(GST_ELEMENT(queue),name);
  return queue;
}

static void gst_queue_cleanup_buffers(gpointer data, gpointer user_data) 
{
  DEBUG("queue: %s cleaning buffer %p\n", (gchar *)user_data, data);
  gst_buffer_unref(GST_BUFFER(data));
}

static void gst_queue_flush(GstQueue *queue) {
  g_slist_foreach(queue->queue, gst_queue_cleanup_buffers, gst_element_get_name(GST_ELEMENT(queue))); 
  g_slist_free(queue->queue);
  queue->queue = NULL;
  queue->level_buffers = 0;
}

static void gst_queue_chain(GstPad *pad,GstBuffer *buf) {
  GstQueue *queue;
  gboolean tosignal = FALSE;
  guchar *name;

  g_return_if_fail(pad != NULL);
  g_return_if_fail(GST_IS_PAD(pad));
  g_return_if_fail(buf != NULL);

  queue = GST_QUEUE(pad->parent);
  name = gst_element_get_name(GST_ELEMENT(queue));

  /* we have to lock the queue since we span threads */
  
  DEBUG("queue: try have queue lock\n");
  GST_LOCK(queue);
  DEBUG("queue: %s adding buffer %p %ld\n", name, buf, pthread_self());
  DEBUG("queue: have queue lock\n");

  if (GST_BUFFER_FLAG_IS_SET(buf, GST_BUFFER_FLUSH)) {
    gst_queue_flush(queue);
  }

  DEBUG("queue: %s: chain %d %p\n", name, queue->level_buffers, buf);

  while (queue->level_buffers >= queue->max_buffers) {
    DEBUG("queue: %s waiting %d\n", name, queue->level_buffers);
    STATUS("%s: O\n");
    GST_UNLOCK(queue);
    g_mutex_lock(queue->fulllock);
    g_cond_wait(queue->fullcond,queue->fulllock);
    g_mutex_unlock(queue->fulllock);
    GST_LOCK(queue);
    STATUS("%s: O+\n");
    DEBUG("queue: %s waiting done %d\n", name, queue->level_buffers);
  }

  /* put the buffer on the tail of the list */
  queue->queue = g_slist_append(queue->queue,buf);
  STATUS("%s: +\n");

  /* if we were empty, but aren't any more, signal a condition */
  tosignal = (queue->level_buffers >= 0);
  queue->level_buffers++;

  /* we can unlock now */
  DEBUG("queue: %s chain %d end signal(%d,%p)\n", name, queue->level_buffers, tosignal, queue->emptycond);
  GST_UNLOCK(queue);

  if (tosignal) {
    g_mutex_lock(queue->emptylock);
    STATUS("%s: >\n");
    g_cond_signal(queue->emptycond);
    STATUS("%s: >>\n");
    g_mutex_unlock(queue->emptylock);
  }
}

static void gst_queue_push(GstConnection *connection) {
  GstQueue *queue = GST_QUEUE(connection);
  GstBuffer *buf = NULL;
  GSList *front;
  gboolean tosignal = FALSE;
  guchar *name;
  
  name = gst_element_get_name(GST_ELEMENT(queue));

  /* have to lock for thread-safety */
  DEBUG("queue: %s try have queue lock\n", name);
  GST_LOCK(queue);
  DEBUG("queue: %s push %d %ld %p\n", name, queue->level_buffers, pthread_self(), queue->emptycond);
  DEBUG("queue: %s have queue lock\n", name);

  while (!queue->level_buffers) {
    STATUS("queue: %s U released lock\n");
    GST_UNLOCK(queue);
    g_mutex_lock(queue->emptylock);
    g_cond_wait(queue->emptycond,queue->emptylock);
    g_mutex_unlock(queue->emptylock);
    GST_LOCK(queue);
    STATUS("queue: %s U- getting lock\n");
  }

  front = queue->queue;
  buf = (GstBuffer *)(front->data);
  queue->queue = g_slist_remove_link(queue->queue,front);
  g_slist_free(front);
  queue->level_buffers--;
  STATUS("%s: -\n");
  tosignal = queue->level_buffers < queue->max_buffers;
  GST_UNLOCK(queue);

  if (tosignal) {
    g_mutex_lock(queue->fulllock);
    STATUS("%s: < \n");
    g_cond_signal(queue->fullcond);
    STATUS("%s: << \n");
    g_mutex_unlock(queue->fulllock);
  }

  DEBUG("queue: %s pushing %d %p \n", name, queue->level_buffers, buf);
  gst_pad_push(queue->srcpad,buf);
  DEBUG("queue: %s pushing %d done \n", name, queue->level_buffers);

  /* unlock now */
}

static GstElementStateReturn gst_queue_change_state(GstElement *element) {
  GstQueue *queue;
  g_return_val_if_fail(GST_IS_QUEUE(element),GST_STATE_FAILURE);

  queue = GST_QUEUE(element);
  DEBUG("gstqueue: state pending %d\n", GST_STATE_PENDING(element));

  /* if going down into NULL state, clear out buffers*/
  if (GST_STATE_PENDING(element) == GST_STATE_READY) {
    /* otherwise (READY or higher) we need to open the file */
    gst_queue_flush(queue);
  }

  /* if we haven't failed already, give the parent class a chance to ;-) */
  if (GST_ELEMENT_CLASS(parent_class)->change_state)
    return GST_ELEMENT_CLASS(parent_class)->change_state(element);

  return GST_STATE_SUCCESS;
}


static void gst_queue_set_arg(GtkObject *object,GtkArg *arg,guint id) {
  GstQueue *queue;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail(GST_IS_QUEUE(object));
  queue = GST_QUEUE(object);

  switch(id) {
    case ARG_MAX_LEVEL:
      queue->max_buffers = GTK_VALUE_INT(*arg);
      break;
    default:
      break;
  }
}

static void gst_queue_get_arg(GtkObject *object,GtkArg *arg,guint id) {
  GstQueue *queue;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail(GST_IS_QUEUE(object));
  queue = GST_QUEUE(object);

  switch (id) {
    case ARG_LEVEL:
      GTK_VALUE_INT(*arg) = queue->level_buffers;
      break;
    case ARG_MAX_LEVEL:
      GTK_VALUE_INT(*arg) = queue->max_buffers;
      break;
    default:
      arg->type = GTK_TYPE_INVALID;
      break;
  }
}