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 program is free software; you can redistribute it and/or
  11  * modify it under the terms of version 2 of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU Lesser General Public License 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, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
  22  * USA
  23  */
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #include <glib/gi18n-lib.h>
  30
  31 #include "camel-stream-null.h"
  32
  33 static void camel_stream_null_seekable_init (GSeekableIface *interface);
  34
  35 G_DEFINE_TYPE_WITH_CODE (CamelStreamNull, camel_stream_null, CAMEL_TYPE_STREAM,
  36         G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE, camel_stream_null_seekable_init))
  37
  38 static gssize
  39 stream_null_write (CamelStream *stream,
  40                    const gchar *buffer,
  41                    gsize n,
  42                    GCancellable *cancellable,
  43                    GError **error)
  44 {
  45         CAMEL_STREAM_NULL (stream)->written += n;
  46
  47         return n;
  48 }
  49
  50 static gboolean
  51 stream_null_eos (CamelStream *stream)
  52 {
  53         return TRUE;
  54 }
  55
  56 static goffset
  57 stream_null_tell (GSeekable *seekable)
  58 {
  59         return 0;
  60 }
  61
  62 static gboolean
  63 stream_null_can_seek (GSeekable *seekable)
  64 {
  65         return TRUE;
  66 }
  67
  68 static gboolean
  69 stream_null_seek (GSeekable *seekable,
  70                   goffset offset,
  71                   GSeekType type,
  72                   GCancellable *cancellable,
  73                   GError **error)
  74 {
  75         if (type != G_SEEK_SET || offset != 0) {
  76                 g_set_error_literal (
  77                         error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
  78                         _("Only reset to beginning is supported with CamelHttpStream"));
  79                 return FALSE;
  80         }
  81
  82         CAMEL_STREAM_NULL (seekable)->written = 0;
  83
  84         return TRUE;
  85 }
  86
  87 static gboolean
  88 stream_null_can_truncate (GSeekable *seekable)
  89 {
  90         return FALSE;
  91 }
  92
  93 static gboolean
  94 stream_null_truncate_fn (GSeekable *seekable,
  95                          goffset offset,
  96                          GCancellable *cancellable,
  97                          GError **error)
  98 {
  99         /* XXX Don't bother translating this.  Camel never calls it. */
 100         g_set_error_literal (
 101                 error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 102                 "Truncation is not supported");
 103
 104         return FALSE;
 105 }
 106
 107 static void
 108 camel_stream_null_class_init (CamelStreamNullClass *class)
 109 {
 110         CamelStreamClass *stream_class;
 111
 112         stream_class = CAMEL_STREAM_CLASS (class);
 113         stream_class->write = stream_null_write;
 114         stream_class->eos = stream_null_eos;
 115 }
 116
 117 static void
 118 camel_stream_null_seekable_init (GSeekableIface *interface)
 119 {
 120         interface->tell = stream_null_tell;
 121         interface->can_seek = stream_null_can_seek;
 122         interface->seek = stream_null_seek;
 123         interface->can_truncate = stream_null_can_truncate;
 124         interface->truncate_fn = stream_null_truncate_fn;
 125 }
 126
 127 static void
 128 camel_stream_null_init (CamelStreamNull *stream_null)
 129 {
 130 }
 131
 132 /**
 133  * camel_stream_null_new:
 134  *
 135  * Returns a null stream.  A null stream is always at eof, and
 136  * always returns success for all reads and writes.
 137  *
 138  * Returns: a new #CamelStreamNull
 139  **/
 140 CamelStream *
 141 camel_stream_null_new (void)
 142 {
 143         return g_object_new (CAMEL_TYPE_STREAM_NULL, NULL);
 144 }