[kdbus] Update kdbus interface header (commit: b620b72c9127) 14/10/16

[platform/upstream/glib.git] / gio / gseekable.c

diff --git a/gio/gseekable.c b/gio/gseekable.c
index 527d9d4..3d89591 100644 (file)
--- a/gio/gseekable.c
+++ b/gio/gseekable.c
@@ -13,66 +13,43 @@
  * 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.
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  *
  * Author: Alexander Larsson <alexl@redhat.com>
  */
 
-#include <config.h>
+#include "config.h"
 #include "gseekable.h"
 #include "glibintl.h"
 
-#include "gioalias.h"
 
 /**
  * SECTION:gseekable
  * @short_description: Stream seeking interface
- * @include: gio.h
+ * @include: gio/gio.h
  * @see_also: #GInputStream, #GOutputStream
- * 
- * #GSeekable is implemented by streams (implementations of 
+ *
+ * #GSeekable is implemented by streams (implementations of
  * #GInputStream or #GOutputStream) that support seeking.
- * 
+ *
+ * Seekable streams largely fall into two categories: resizable and
+ * fixed-size.
+ *
+ * #GSeekable on fixed-sized streams is approximately the same as POSIX
+ * lseek() on a block device (for example: attmepting to seek past the
+ * end of the device is an error).  Fixed streams typically cannot be
+ * truncated.
+ *
+ * #GSeekable on resizable streams is approximately the same as POSIX
+ * lseek() on a normal file.  Seeking past the end and writing data will
+ * usually cause the stream to resize by introducing zero bytes.
  **/
 
-
-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;
-}
+typedef GSeekableIface GSeekableInterface;
+G_DEFINE_INTERFACE (GSeekable, g_seekable, G_TYPE_OBJECT)
 
 static void
-g_seekable_base_init (gpointer g_class)
+g_seekable_default_init (GSeekableInterface *iface)
 {
 }
 
@@ -121,18 +98,27 @@ g_seekable_can_seek (GSeekable *seekable)
  * @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 
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
+ * @error: a #GError location to store the error occurring, or %NULL to
  * ignore.
- * 
+ *
  * Seeks in the stream by the given @offset, modified by @type.
  *
+ * Attempting to seek past the end of the stream will have different
+ * results depending on if the stream is fixed-sized or resizable.  If
+ * the stream is resizable then seeking past the end and then writing
+ * will result in zeros filling the empty space.  Seeking past the end
+ * of a resizable stream and reading will result in EOF.  Seeking past
+ * the end of a fixed-sized stream will fail.
+ *
+ * Any operation that would result in a negative offset will fail.
+ *
  * 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
+ *     has occurred, this function will return %FALSE and set @error
  *     appropriately if present.
  **/
 gboolean
@@ -175,8 +161,8 @@ g_seekable_can_truncate (GSeekable *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 
+ * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. 
+ * @error: a #GError location to store the error occurring, or %NULL to 
  * ignore.
  * 
  * Truncates a stream with a given #offset. 
@@ -186,9 +172,10 @@ g_seekable_can_truncate (GSeekable *seekable)
  * 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.
- * 
+ *
+ * Virtual: truncate_fn
  * Returns: %TRUE if successful. If an error
- *     has occured, this function will return %FALSE and set @error
+ *     has occurred, this function will return %FALSE and set @error
  *     appropriately if present. 
  **/
 gboolean
@@ -205,6 +192,3 @@ g_seekable_truncate (GSeekable     *seekable,
 
   return (* iface->truncate_fn) (seekable, offset, cancellable, error);
 }
-
-#define __G_SEEKABLE_C__
-#include "gioaliasdef.c"