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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#include <config.h>
#include "gseekable.h"
#include "glibintl.h"
/**
* SECTION:gseekable
* @short_description: Stream seeking interface
* @see_also: #GInputStream, #GOutputStream
*
* #GSeekable is implemented by streams (implementations of
* #GInputStream or #GOutputStream) that support seeking.
*
**/
static void g_seekable_base_init (gpointer g_class);
GType
g_seekable_get_type (void)
{
static GType seekable_type = 0;
if (! seekable_type)
{
static const GTypeInfo seekable_info =
{
sizeof (GSeekableIface), /* class_size */
g_seekable_base_init, /* base_init */
NULL, /* base_finalize */
NULL,
NULL, /* class_finalize */
NULL, /* class_data */
0,
0, /* n_preallocs */
NULL
};
seekable_type =
g_type_register_static (G_TYPE_INTERFACE, I_("GSeekable"),
&seekable_info, 0);
g_type_interface_add_prerequisite (seekable_type, G_TYPE_OBJECT);
}
return seekable_type;
}
static void
g_seekable_base_init (gpointer g_class)
{
}
/**
* g_seekable_tell:
* @seekable: a #GSeekable.
*
* Tells the current position within the stream.
*
* Returns: the offset from the beginning of the buffer.
**/
goffset
g_seekable_tell (GSeekable *seekable)
{
GSeekableIface *iface;
g_return_val_if_fail (G_IS_SEEKABLE (seekable), 0);
iface = G_SEEKABLE_GET_IFACE (seekable);
return (* iface->tell) (seekable);
}
/**
* g_seekable_can_seek:
* @seekable: a #GSeekable.
*
* Tests if the stream supports the #GSeekableIface.
*
* Returns: %TRUE if @seekable can be seeked. %FALSE otherwise.
**/
gboolean
g_seekable_can_seek (GSeekable *seekable)
{
GSeekableIface *iface;
g_return_val_if_fail (G_IS_SEEKABLE (seekable), FALSE);
iface = G_SEEKABLE_GET_IFACE (seekable);
return (* iface->can_seek) (seekable);
}
/**
* g_seekable_seek:
* @seekable: a #GSeekable.
* @offset: a #goffset.
* @type: a #GSeekType.
* @cancellable: optional #GCancellable object, %NULL to ignore.
* @error: a #GError location to store the error occuring, or %NULL to
* ignore.
*
* Seeks in the stream by the given @offset, modified by @type.
*
* If @cancellable is not %NULL, then the operation can be cancelled by
* triggering the cancellable object from another thread. If the operation
* was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
*
* Returns: %TRUE if successful. If an error
* has occured, this function will return %FALSE and set @error
* appropriately if present.
**/
gboolean
g_seekable_seek (GSeekable *seekable,
goffset offset,
GSeekType type,
GCancellable *cancellable,
GError **error)
{
GSeekableIface *iface;
g_return_val_if_fail (G_IS_SEEKABLE (seekable), FALSE);
iface = G_SEEKABLE_GET_IFACE (seekable);
return (* iface->seek) (seekable, offset, type, cancellable, error);
}
/**
* g_seekable_can_truncate:
* @seekable: a #GSeekable.
*
* Tests if the stream can be truncated.
*
* Returns: %TRUE if the stream can be truncated, %FALSE otherwise.
**/
gboolean
g_seekable_can_truncate (GSeekable *seekable)
{
GSeekableIface *iface;
g_return_val_if_fail (G_IS_SEEKABLE (seekable), FALSE);
iface = G_SEEKABLE_GET_IFACE (seekable);
return (* iface->can_truncate) (seekable);
}
/**
* g_seekable_truncate:
* @seekable: a #GSeekable.
* @offset: a #goffset.
* @cancellable: optional #GCancellable object, %NULL to ignore.
* @error: a #GError location to store the error occuring, or %NULL to
* ignore.
*
* Truncates a stream with a given #offset.
*
* If @cancellable is not %NULL, then the operation can be cancelled by
* triggering the cancellable object from another thread. If the operation
* was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
* operation was partially finished when the operation was cancelled the
* partial result will be returned, without an error.
*
* Returns: %TRUE if successful. If an error
* has occured, this function will return %FALSE and set @error
* appropriately if present.
**/
gboolean
g_seekable_truncate (GSeekable *seekable,
goffset offset,
GCancellable *cancellable,
GError **error)
{
GSeekableIface *iface;
g_return_val_if_fail (G_IS_SEEKABLE (seekable), FALSE);
iface = G_SEEKABLE_GET_IFACE (seekable);
return (* iface->truncate) (seekable, offset, cancellable, error);
}
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