/* GStreamer

 * Copyright (C) 2017 Matthew Waters <matthew@centricular.com>

 *

 * 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., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

#ifndef __GST_PROMISE_H__

#define __GST_PROMISE_H__

#include <gst/gst.h>

G_BEGIN_DECLS

GST_API

GType gst_promise_get_type(void);

#define GST_TYPE_PROMISE            (gst_promise_get_type())

#define GST_PROMISE(obj)            ((GstPromise *) obj)

typedef struct _GstPromise GstPromise;

/**

 * GstPromiseResult:

 * @GST_PROMISE_RESULT_PENDING: Initial state. Waiting for transition to any

 * 	other state.

 * @GST_PROMISE_RESULT_INTERRUPTED: Interrupted by the consumer as it doesn't

 * 	want the value anymore.

 * @GST_PROMISE_RESULT_REPLIED: A producer marked a reply

 * @GST_PROMISE_RESULT_EXPIRED: The promise expired (the carrying object

 * 	lost all refs) and the promise will never be fulfilled.

 *

 * The result of a #GstPromise

 *

 * Since: 1.14

 */

typedef enum

{

  GST_PROMISE_RESULT_PENDING,

  GST_PROMISE_RESULT_INTERRUPTED,

  GST_PROMISE_RESULT_REPLIED,

  GST_PROMISE_RESULT_EXPIRED,

} GstPromiseResult;

/**

 * GstPromiseChangeFunc:

 * @promise: a #GstPromise

 * @user_data: (closure): user data

 *

 * Since: 1.14

 */

typedef void (*GstPromiseChangeFunc) (GstPromise * promise, gpointer user_data);

/**

 * GstPromise:

 * @parent: parent #GstMiniObject

 *

 * Since: 1.14

 */

struct _GstPromise

{

  GstMiniObject         parent;

};

GST_API

GstPromise *            gst_promise_new                     (void);

GST_API

GstPromise *            gst_promise_new_with_change_func    (GstPromiseChangeFunc func,

                                                             gpointer user_data,

                                                             GDestroyNotify notify);

GST_API

GstPromiseResult        gst_promise_wait                    (GstPromise * promise);

GST_API

void                    gst_promise_reply                   (GstPromise * promise,

                                                             GstStructure * s);

GST_API

void                    gst_promise_interrupt               (GstPromise * promise);

GST_API

void                    gst_promise_expire                  (GstPromise * promise);

GST_API

const GstStructure *    gst_promise_get_reply               (GstPromise * promise);

/**

 * gst_promise_ref:

 * @promise: a #GstPromise.

 *

 * Increases the refcount of the given @promise by one.

 *

 * Returns: (transfer full): @promise

 *

 * Since: 1.14

 */

static inline GstPromise *

gst_promise_ref (GstPromise * promise)

{

  return (GstPromise *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (promise));

}

/**

 * gst_promise_unref:

 * @promise: (transfer full): a #GstPromise.

 *

 * Decreases the refcount of the promise. If the refcount reaches 0, the

 * promise will be freed.

 *

 * Since: 1.14

 */

static inline void

gst_promise_unref (GstPromise * promise)

{

  gst_mini_object_unref (GST_MINI_OBJECT_CAST (promise));

}

G_END_DECLS

#endif /* __GST_PROMISE_H__ */