camel/camel-stream-null.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; fill-column: 160 -*- */
   2 /* camel-stream.c : abstract class for a stream */
   3
   4 /*
   5  * Author:
   6  *  Michael Zucchi <notzed@ximian.com>
   7  *
   8  * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
   9  *
  10  * This library is free software you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation.
  13  *
  14  * This library is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17  *for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <glib/gi18n-lib.h>
  28
  29 #include "camel-stream-null.h"
  30
  31 static void camel_stream_null_seekable_init (GSeekableIface *iface);
  32
  33 G_DEFINE_TYPE_WITH_CODE (CamelStreamNull, camel_stream_null, CAMEL_TYPE_STREAM,
  34         G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE, camel_stream_null_seekable_init))
  35
  36 static gssize
  37 stream_null_write (CamelStream *stream,
  38                    const gchar *buffer,
  39                    gsize n,
  40                    GCancellable *cancellable,
  41                    GError **error)
  42 {
  43         CAMEL_STREAM_NULL (stream)->written += n;
  44
  45         return n;
  46 }
  47
  48 static gboolean
  49 stream_null_eos (CamelStream *stream)
  50 {
  51         return TRUE;
  52 }
  53
  54 static goffset
  55 stream_null_tell (GSeekable *seekable)
  56 {
  57         return 0;
  58 }
  59
  60 static gboolean
  61 stream_null_can_seek (GSeekable *seekable)
  62 {
  63         return TRUE;
  64 }
  65
  66 static gboolean
  67 stream_null_seek (GSeekable *seekable,
  68                   goffset offset,
  69                   GSeekType type,
  70                   GCancellable *cancellable,
  71                   GError **error)
  72 {
  73         if (type != G_SEEK_SET || offset != 0) {
  74                 g_set_error_literal (
  75                         error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
  76                         _("Only reset to beginning is supported with CamelHttpStream"));
  77                 return FALSE;
  78         }
  79
  80         CAMEL_STREAM_NULL (seekable)->written = 0;
  81
  82         return TRUE;
  83 }
  84
  85 static gboolean
  86 stream_null_can_truncate (GSeekable *seekable)
  87 {
  88         return FALSE;
  89 }
  90
  91 static gboolean
  92 stream_null_truncate_fn (GSeekable *seekable,
  93                          goffset offset,
  94                          GCancellable *cancellable,
  95                          GError **error)
  96 {
  97         /* XXX Don't bother translating this.  Camel never calls it. */
  98         g_set_error_literal (
  99                 error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 100                 "Truncation is not supported");
 101
 102         return FALSE;
 103 }
 104
 105 static void
 106 camel_stream_null_class_init (CamelStreamNullClass *class)
 107 {
 108         CamelStreamClass *stream_class;
 109
 110         stream_class = CAMEL_STREAM_CLASS (class);
 111         stream_class->write = stream_null_write;
 112         stream_class->eos = stream_null_eos;
 113 }
 114
 115 static void
 116 camel_stream_null_seekable_init (GSeekableIface *iface)
 117 {
 118         iface->tell = stream_null_tell;
 119         iface->can_seek = stream_null_can_seek;
 120         iface->seek = stream_null_seek;
 121         iface->can_truncate = stream_null_can_truncate;
 122         iface->truncate_fn = stream_null_truncate_fn;
 123 }
 124
 125 static void
 126 camel_stream_null_init (CamelStreamNull *stream_null)
 127 {
 128 }
 129
 130 /**
 131  * camel_stream_null_new:
 132  *
 133  * Returns a null stream.  A null stream is always at eof, and
 134  * always returns success for all reads and writes.
 135  *
 136  * Returns: a new #CamelStreamNull
 137  **/
 138 CamelStream *
 139 camel_stream_null_new (void)
 140 {
 141         return g_object_new (CAMEL_TYPE_STREAM_NULL, NULL);
 142 }