source: trunk/third/gstreamer/gst/gstdata.h @ 21005

/* GStreamer
 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
 *                    2000 Wim Taymans <wim.taymans@chello.be>
 *
 * gstdata.h: Header for GstData objects (used for data passing)
 *
 * 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.
 */


#ifndef __GST_DATA_H__
#define __GST_DATA_H__

#include <glib-object.h>
#include <gst/gstatomic.h>
#include <gst/gsttypes.h>

G_BEGIN_DECLS

/* type */
#define GST_DATA(data)          ((GstData*)(data))
#define GST_DATA_TYPE(data)     (GST_DATA(data)->type)

/* flags */
#define GST_DATA_FLAGS(data)            (GST_DATA(data)->flags)
#define GST_DATA_FLAG_SHIFT(flag)       (1<<(flag))
#define GST_DATA_FLAG_IS_SET(data,flag) (GST_DATA_FLAGS(data) & (1<<(flag)))
#define GST_DATA_FLAG_SET(data,flag)    G_STMT_START{ (GST_DATA_FLAGS(data) |= (1<<(flag))); }G_STMT_END
#define GST_DATA_FLAG_UNSET(data,flag)  G_STMT_START{ (GST_DATA_FLAGS(data) &= ~(1<<(flag))); }G_STMT_END

/* Macros for the GType */
#define GST_TYPE_DATA                   (gst_data_get_type ())

typedef struct _GstData GstData;

typedef void            (*GstDataFreeFunction)          (GstData *data);
typedef GstData*        (*GstDataCopyFunction)          (const GstData *data);

typedef enum
{
  GST_DATA_READONLY     = 1,

  /* insert more */
  GST_DATA_FLAG_LAST    = 8
} GstDataFlags;

/* refcount */
#define GST_DATA_REFCOUNT(data)                 ((GST_DATA(data))->refcount)
#define GST_DATA_REFCOUNT_VALUE(data)           (gst_atomic_int_read (&(GST_DATA(data))->refcount))

/* copy/free functions */
#define GST_DATA_COPY_FUNC(data)                (GST_DATA(data)->copy)
#define GST_DATA_FREE_FUNC(data)                (GST_DATA(data)->free)


struct _GstData {
  GType                  type;

  /* refcounting */
  GstAtomicInt           refcount;

  guint16                flags;
 
  /* utility function pointers, can override default */
  GstDataFreeFunction    free;          /* free the data */
  GstDataCopyFunction    copy;          /* copy the data */

  gpointer _gst_reserved[GST_PADDING];
};

/* function used by subclasses only */
void                    gst_data_init                   (GstData *data, GType type, guint16 flags,
                                                         GstDataFreeFunction free,
                                                         GstDataCopyFunction copy);
void                    gst_data_dispose                (GstData *data);
void                    gst_data_copy_into              (const GstData *data, GstData *target);

/* basic operations on data */
GstData*                gst_data_copy                   (const GstData *data);
gboolean                gst_data_is_writable            (GstData *data);
GstData*                gst_data_copy_on_write          (GstData *data);

/* reference counting */
GstData*                gst_data_ref                    (GstData* data);
GstData*                gst_data_ref_by_count           (GstData* data, gint count);
void                    gst_data_unref                  (GstData* data);

/* GType for GstData */
GType                   gst_data_get_type               (void) G_GNUC_CONST;

G_END_DECLS

#endif /* __GST_DATA_H__ */