/* GStreamer

 * Copyright (C) 2006 Edward Hervey <edward@fluendo.com>

 *

 * gstdataqueue.c:

 *

 * 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.

 */

/**

 * SECTION:gstdataqueue

 * @short_description: Threadsafe queueing object

 *

 * #GstDataQueue is an object that handles threadsafe queueing of objects. It

 * also provides size-related functionality. This object should be used for

 * any #GstElement that wishes to provide some sort of queueing functionality.

 */

#include <gst/gst.h>

#include "gstdataqueue.h"

GST_DEBUG_CATEGORY_STATIC (data_queue_debug);

#define GST_CAT_DEFAULT (data_queue_debug)

GST_DEBUG_CATEGORY_STATIC (data_queue_dataflow);

/* Queue signals and args */

enum

{

  SIGNAL_EMPTY,

  SIGNAL_FULL,

  LAST_SIGNAL

};

enum

{

  ARG_0,

  ARG_CUR_LEVEL_VISIBLE,

  ARG_CUR_LEVEL_BYTES,

  ARG_CUR_LEVEL_TIME

      /* FILL ME */

};

#define GST_DATA_QUEUE_MUTEX_LOCK(q) G_STMT_START {                     \

    GST_CAT_LOG (data_queue_dataflow,                                   \

      "locking qlock from thread %p",                                   \

      g_thread_self ());                                                \

  g_mutex_lock (q->qlock);                                              \

  GST_CAT_LOG (data_queue_dataflow,                                     \

      "locked qlock from thread %p",                                    \

      g_thread_self ());                                                \

} G_STMT_END

#define GST_DATA_QUEUE_MUTEX_LOCK_CHECK(q, label) G_STMT_START {        \

    GST_DATA_QUEUE_MUTEX_LOCK (q);                                      \

    if (q->flushing)                                                    \

      goto label;                                                       \

  } G_STMT_END

#define GST_DATA_QUEUE_MUTEX_UNLOCK(q) G_STMT_START {                   \

    GST_CAT_LOG (data_queue_dataflow,                                   \

      "unlocking qlock from thread %p",                                 \

      g_thread_self ());                                                \

  g_mutex_unlock (q->qlock);                                            \

} G_STMT_END

#define STATUS(q, msg)                                                  \

  GST_CAT_LOG (data_queue_dataflow,                                     \

               "queue:%p " msg ": %u visible items, %u "                \

               "bytes, %"G_GUINT64_FORMAT                               \

               " ns, %u elements",                                      \

               queue,                                                   \

               q->cur_level.visible,                                    \

               q->cur_level.bytes,                                      \

               q->cur_level.time,                                       \

               q->queue->length)

static void gst_data_queue_base_init (GstDataQueueClass * klass);

static void gst_data_queue_class_init (GstDataQueueClass * klass);

static void gst_data_queue_init (GstDataQueue * queue);

static void gst_data_queue_finalize (GObject * object);

static void gst_data_queue_set_property (GObject * object,

    guint prop_id, const GValue * value, GParamSpec * pspec);

static void gst_data_queue_get_property (GObject * object,

    guint prop_id, GValue * value, GParamSpec * pspec);

static GObjectClass *parent_class = NULL;

static guint gst_data_queue_signals[LAST_SIGNAL] = { 0 };

GType

gst_data_queue_get_type (void)

{

  static GType queue_type = 0;

  if (!queue_type) {

    static const GTypeInfo queue_info = {

      sizeof (GstDataQueueClass),

      (GBaseInitFunc) gst_data_queue_base_init,

      NULL,

      (GClassInitFunc) gst_data_queue_class_init,

      NULL,

      NULL,

      sizeof (GstDataQueue),

      0,

      (GInstanceInitFunc) gst_data_queue_init,

      NULL

    };

    queue_type = g_type_register_static (G_TYPE_OBJECT,

        "GstDataQueue", &queue_info, 0);

    GST_DEBUG_CATEGORY_INIT (data_queue_debug, "dataqueue", 0,

        "data queue object");

    GST_DEBUG_CATEGORY_INIT (data_queue_dataflow, "data_queue_dataflow", 0,

        "dataflow inside the data queue object");

  }

  return queue_type;

}

static void

gst_data_queue_base_init (GstDataQueueClass * klass)

{

  /* Do we need anything here ?? */

  return;

}

static void

gst_data_queue_class_init (GstDataQueueClass * klass)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  parent_class = g_type_class_peek_parent (klass);

  gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_data_queue_set_property);

  gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_data_queue_get_property);

  /* signals */

  /**

   * GstDataQueue::empty:

   * @queue: the queue instance

   *

   * Reports that the queue became empty (empty).

   * A queue is empty if the total amount of visible items inside it (num-visible, time,

   * size) is lower than the boundary values which can be set through the GObject

   * properties.

   */

  gst_data_queue_signals[SIGNAL_EMPTY] =

      g_signal_new ("empty", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST,

      G_STRUCT_OFFSET (GstDataQueueClass, empty), NULL, NULL,

      g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);

  /**

   * GstDataQueue::full:

   * @queue: the queue instance

   *

   * Reports that the queue became full (full).

   * A queue is full if the total amount of data inside it (num-visible, time,

   * size) is higher than the boundary values which can be set through the GObject

   * properties.

   */

  gst_data_queue_signals[SIGNAL_FULL] =

      g_signal_new ("full", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST,

      G_STRUCT_OFFSET (GstDataQueueClass, full), NULL, NULL,

      g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);

  /* properties */

  g_object_class_install_property (gobject_class, ARG_CUR_LEVEL_BYTES,

      g_param_spec_uint ("current-level-bytes", "Current level (kB)",

          "Current amount of data in the queue (bytes)",

          0, G_MAXUINT, 0, G_PARAM_READABLE));

  g_object_class_install_property (gobject_class, ARG_CUR_LEVEL_VISIBLE,

      g_param_spec_uint ("current-level-visible",

          "Current level (visible items)",

          "Current number of visible items in the queue", 0, G_MAXUINT, 0,

          G_PARAM_READABLE));

  g_object_class_install_property (gobject_class, ARG_CUR_LEVEL_TIME,

      g_param_spec_uint64 ("current-level-time", "Current level (ns)",

          "Current amount of data in the queue (in ns)", 0, G_MAXUINT64, 0,

          G_PARAM_READABLE));

  /* set several parent class virtual functions */

  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_data_queue_finalize);

}

static void

gst_data_queue_init (GstDataQueue * queue)

{

  queue->cur_level.visible = 0; /* no content */

  queue->cur_level.bytes = 0;   /* no content */

  queue->cur_level.time = 0;    /* no content */

  queue->checkfull = NULL;

  queue->qlock = g_mutex_new ();

  queue->item_add = g_cond_new ();

  queue->item_del = g_cond_new ();

  queue->queue = g_queue_new ();

  GST_DEBUG ("initialized queue's not_empty & not_full conditions");

}

/**

 * gst_data_queue_new:

 * @checkfull: the callback used to tell if the element considers the queue full

 * or not.

 * @checkdata: a #gpointer that will be given in the @checkfull callback.

 *

 * Returns: a new #GstDataQueue.

 */

GstDataQueue *

gst_data_queue_new (GstDataQueueCheckFullFunction checkfull, gpointer checkdata)

{

  GstDataQueue *ret;

  g_return_val_if_fail (checkfull != NULL, NULL);

  ret = g_object_new (GST_TYPE_DATA_QUEUE, NULL);

  ret->checkfull = checkfull;

  ret->checkdata = checkdata;

  return ret;

}

static void

gst_data_queue_cleanup (GstDataQueue * queue)

{

  while (!g_queue_is_empty (queue->queue)) {

    GstDataQueueItem *item = g_queue_pop_head (queue->queue);

    /* Just call the destroy notify on the item */

    item->destroy (item);

  }

  queue->cur_level.visible = 0;

  queue->cur_level.bytes = 0;

  queue->cur_level.time = 0;

}

/* called only once, as opposed to dispose */

static void

gst_data_queue_finalize (GObject * object)

{

  GstDataQueue *queue = GST_DATA_QUEUE (object);

  GST_DEBUG ("finalizing queue");

  gst_data_queue_cleanup (queue);

  g_queue_free (queue->queue);

  GST_DEBUG ("free mutex");

  g_mutex_free (queue->qlock);

  GST_DEBUG ("done free mutex");

  g_cond_free (queue->item_add);

  g_cond_free (queue->item_del);

  G_OBJECT_CLASS (parent_class)->finalize (object);

}

static void

gst_data_queue_locked_flush (GstDataQueue * queue)

{

  STATUS (queue, "before flushing");

  gst_data_queue_cleanup (queue);

  STATUS (queue, "after flushing");

  /* we deleted something... */

  g_cond_signal (queue->item_del);

}

static gboolean

gst_data_queue_locked_is_empty (GstDataQueue * queue)

{

  return (queue->queue->length == 0);

}

static gboolean

gst_data_queue_locked_is_full (GstDataQueue * queue)

{

  return queue->checkfull (queue, queue->cur_level.visible,

      queue->cur_level.bytes, queue->cur_level.time, queue->checkdata);

}

/**

 * gst_data_queue_flush:

 * @queue: a #GstDataQueue.

 *

 * Flushes all the contents of the @queue. Any call to #gst_data_queue_pull and

 * #gst_data_queue_pop will be released.

 * MT safe.

 */

void

gst_data_queue_flush (GstDataQueue * queue)

{

  GST_DEBUG ("queue:%p", queue);

  GST_DATA_QUEUE_MUTEX_LOCK (queue);

  gst_data_queue_locked_flush (queue);

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

}

/**

 * gst_data_queue_is_empty:

 * @queue: a #GstDataQueue.

 *

 * Queries if there are any items in the @queue.

 * MT safe.

 *

 * Returns: #TRUE if @queue is empty.

 */

gboolean

gst_data_queue_is_empty (GstDataQueue * queue)

{

  gboolean res;

  GST_DATA_QUEUE_MUTEX_LOCK (queue);

  res = gst_data_queue_locked_is_empty (queue);

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

  return res;

}

/**

 * gst_data_queue_is_full:

 * @queue: a #GstDataQueue.

 *

 * Queries if @queue is full. This check will be done using the

 * #GstDataQueueCheckFullCallback registered with @queue.

 * MT safe.

 *

 * Returns: #TRUE if @queue is full.

 */

gboolean

gst_data_queue_is_full (GstDataQueue * queue)

{

  gboolean res;

  GST_DATA_QUEUE_MUTEX_LOCK (queue);

  res = gst_data_queue_locked_is_full (queue);

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

  return res;

}

/**

 * gst_data_queue_set_flushing:

 * @queue: a #GstDataQueue.

 * @flushing: a #gboolean stating if the queue will be flushing or not.

 *

 * Sets the queue to flushing state if @flushing is #TRUE. If set to flushing

 * state, any incoming data on the @queue will be discarded. Any call currently

 * blocking on #gst_data_queue_push or #gst_data_queue_pop will return straight

 * away with a return value of #FALSE. While the @queue is in flushing state, 

 * all calls to those two functions will return #FALSE.

 *

 * MT Safe.

 */

void

gst_data_queue_set_flushing (GstDataQueue * queue, gboolean flushing)

{

  GST_DEBUG ("queue:%p , flushing:%d", queue, flushing);

  GST_DATA_QUEUE_MUTEX_LOCK (queue);

  queue->flushing = flushing;

  if (flushing) {

    /* release push/pop functions */

    g_cond_signal (queue->item_add);

    g_cond_signal (queue->item_del);

  }

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

}

/**

 * gst_data_queue_push:

 * @queue: a #GstDataQueue.

 * @item: a #GstDataQueueItem.

 *

 * Pushes a #GstDataQueueItem (or a structure that begins with the same fields)

 * on the @queue. If the @queue is full, the call will block until space is

 * available, OR the @queue is set to flushing state.

 * MT safe.

 *

 * Note that this function has slightly different semantics than gst_pad_push()

 * and gst_pad_push_event(): this function only takes ownership of @item and

 * the #GstMiniObject contained in @item if the push was successful. If FALSE

 * is returned, the caller is responsible for freeing @item and its contents.

 *

 * Returns: #TRUE if the @item was successfully pushed on the @queue.

 */

gboolean

gst_data_queue_push (GstDataQueue * queue, GstDataQueueItem * item)

{

  g_return_val_if_fail (GST_IS_DATA_QUEUE (queue), FALSE);

  g_return_val_if_fail (item != NULL, FALSE);

  GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);

  STATUS (queue, "before pushing");

  /* We ALWAYS need to check for queue fillness */

  if (gst_data_queue_locked_is_full (queue)) {

    GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

    g_signal_emit (G_OBJECT (queue), gst_data_queue_signals[SIGNAL_FULL], 0);

    GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);

    /* signal might have removed some items */

    while (gst_data_queue_locked_is_full (queue)) {

      g_cond_wait (queue->item_del, queue->qlock);

      if (queue->flushing)

        goto flushing;

    }

  }

  g_queue_push_tail (queue->queue, item);

  if (item->visible)

    queue->cur_level.visible++;

  queue->cur_level.bytes += item->size;

  queue->cur_level.time += item->duration;

  STATUS (queue, "after pushing");

  g_cond_signal (queue->item_add);

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

  return TRUE;

  /* ERRORS */

flushing:

  {

    GST_DEBUG ("queue:%p, we are flushing", queue);

    GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

    return FALSE;

  }

}

/**

 * gst_data_queue_pop:

 * @queue: a #GstDataQueue.

 * @item: pointer to store the returned #GstDataQueueItem.

 *

 * Retrieves the first @item available on the @queue. If the queue is currently

 * empty, the call will block until at least one item is available, OR the

 * @queue is set to the flushing state.

 * MT safe.

 *

 * Returns: #TRUE if an @item was successfully retrieved from the @queue.

 */

gboolean

gst_data_queue_pop (GstDataQueue * queue, GstDataQueueItem ** item)

{

  g_return_val_if_fail (GST_IS_DATA_QUEUE (queue), FALSE);

  g_return_val_if_fail (item != NULL, FALSE);

  GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);

  STATUS (queue, "before popping");

  if (gst_data_queue_locked_is_empty (queue)) {

    GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

    g_signal_emit (G_OBJECT (queue), gst_data_queue_signals[SIGNAL_EMPTY], 0);

    GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);

    while (gst_data_queue_locked_is_empty (queue)) {

      g_cond_wait (queue->item_add, queue->qlock);

      if (queue->flushing)

        goto flushing;

    }

  }

  /* Get the item from the GQueue */

  *item = g_queue_pop_head (queue->queue);

  /* update current level counter */

  if ((*item)->visible)

    queue->cur_level.visible--;

  queue->cur_level.bytes -= (*item)->size;

  queue->cur_level.time -= (*item)->duration;

  STATUS (queue, "after popping");

  g_cond_signal (queue->item_del);

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

  return TRUE;

  /* ERRORS */

flushing:

  {

    GST_DEBUG ("queue:%p, we are flushing", queue);

    GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

    return FALSE;

  }

}

/**

 * gst_data_queue_drop_head:

 * @queue: The #GstDataQueue to drop an item from.

 * @type: The #GType of the item to drop.

 *

 * Pop and unref the head-most #GstMiniObject with the given #GType.

 *

 * Returns: TRUE if an element was removed.

 */

gboolean

gst_data_queue_drop_head (GstDataQueue * queue, GType type)

{

  gboolean res = FALSE;

  GList *item;

  GstDataQueueItem *leak = NULL;

  g_return_val_if_fail (GST_IS_DATA_QUEUE (queue), FALSE);

  GST_DEBUG ("queue:%p", queue);

  GST_DATA_QUEUE_MUTEX_LOCK (queue);

  for (item = g_queue_peek_head_link (queue->queue); item; item = item->next) {

    GstDataQueueItem *tmp = (GstDataQueueItem *) item->data;

    if (G_TYPE_CHECK_INSTANCE_TYPE (tmp->object, type)) {

      leak = tmp;

      break;

    }

  }

  if (!leak)

    goto done;

  g_queue_delete_link (queue->queue, item);

  if (leak->visible)

    queue->cur_level.visible--;

  queue->cur_level.bytes -= leak->size;

  queue->cur_level.time -= leak->duration;

  leak->destroy (leak);

  res = TRUE;

done:

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

  GST_DEBUG ("queue:%p , res:%d", queue, res);

  return res;

}

/**

 * gst_data_queue_limits_changed:

 * @queue: The #GstDataQueue 

 *

 * Inform the queue that the limits for the fullness check have changed and that

 * any blocking gst_data_queue_push() should be unblocked to recheck the limts.

 */

void

gst_data_queue_limits_changed (GstDataQueue * queue)

{

  g_return_if_fail (GST_IS_DATA_QUEUE (queue));

  GST_DATA_QUEUE_MUTEX_LOCK (queue);

  GST_DEBUG ("signal del");

  g_cond_signal (queue->item_del);

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

}

/**

 * gst_data_queue_get_level:

 * @queue: The #GstDataQueue

 * @level: the location to store the result

 *

 * Get the current level of the queue.

 */

void

gst_data_queue_get_level (GstDataQueue * queue, GstDataQueueSize * level)

{

  level->visible = queue->cur_level.visible;

  level->bytes = queue->cur_level.bytes;

  level->time = queue->cur_level.time;

}

static void

gst_data_queue_set_property (GObject * object,

    guint prop_id, const GValue * value, GParamSpec * pspec)

{

  switch (prop_id) {

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

}

static void

gst_data_queue_get_property (GObject * object,

    guint prop_id, GValue * value, GParamSpec * pspec)

{

  GstDataQueue *queue = GST_DATA_QUEUE (object);

  GST_DATA_QUEUE_MUTEX_LOCK (queue);

  switch (prop_id) {

    case ARG_CUR_LEVEL_BYTES:

      g_value_set_uint (value, queue->cur_level.bytes);

      break;

    case ARG_CUR_LEVEL_VISIBLE:

      g_value_set_uint (value, queue->cur_level.visible);

      break;

    case ARG_CUR_LEVEL_TIME:

      g_value_set_uint64 (value, queue->cur_level.time);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

  GST_DATA_QUEUE_MUTEX_UNLOCK (queue);

}