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 1999, 2000 Ximian, Inc. (www.ximian.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 "camel-stream-null.h"
  30
  31 static CamelObjectClass *parent_class = NULL;
  32
  33 /* Returns the class for a CamelStream */
  34 #define CS_CLASS(so) CAMEL_STREAM_NULL_CLASS(CAMEL_OBJECT_GET_CLASS(so))
  35
  36 /* dummy implementations, for a NULL stream */
  37 static ssize_t   stream_read       (CamelStream *stream, char *buffer, size_t n) { return 0; }
  38 static ssize_t   stream_write      (CamelStream *stream, const char *buffer, size_t n) { ((CamelStreamNull *)stream)->written += n; return n; }
  39 static int       stream_close      (CamelStream *stream) { return 0; }
  40 static int       stream_flush      (CamelStream *stream) { return 0; }
  41 static gboolean  stream_eos        (CamelStream *stream) { return TRUE; }
  42 static int       stream_reset      (CamelStream *stream) { ((CamelStreamNull *)stream)->written = 0; return 0; }
  43
  44 static void
  45 camel_stream_null_class_init (CamelStreamClass *camel_stream_null_class)
  46 {
  47         CamelStreamClass *camel_stream_class = (CamelStreamClass *)camel_stream_null_class;
  48
  49         parent_class = camel_type_get_global_classfuncs( CAMEL_OBJECT_TYPE );
  50
  51         /* virtual method definition */
  52         camel_stream_class->read = stream_read;
  53         camel_stream_class->write = stream_write;
  54         camel_stream_class->close = stream_close;
  55         camel_stream_class->flush = stream_flush;
  56         camel_stream_class->eos = stream_eos;
  57         camel_stream_class->reset = stream_reset;
  58 }
  59
  60 CamelType
  61 camel_stream_null_get_type (void)
  62 {
  63         static CamelType camel_stream_null_type = CAMEL_INVALID_TYPE;
  64
  65         if (camel_stream_null_type == CAMEL_INVALID_TYPE) {
  66                 camel_stream_null_type = camel_type_register( camel_stream_get_type(),
  67                                                               "CamelStreamNull",
  68                                                               sizeof( CamelStreamNull ),
  69                                                               sizeof( CamelStreamNullClass ),
  70                                                               (CamelObjectClassInitFunc) camel_stream_null_class_init,
  71                                                               NULL,
  72                                                               NULL,
  73                                                               NULL );
  74         }
  75
  76         return camel_stream_null_type;
  77 }
  78
  79 /**
  80  * camel_stream_null_new:
  81  *
  82  * Returns a null stream.  A null stream is always at eof, and
  83  * always returns success for all reads and writes.
  84  *
  85  * Returns a new #CamelStreamNull
  86  **/
  87 CamelStream *
  88 camel_stream_null_new(void)
  89 {
  90         return (CamelStream *)camel_object_new(camel_stream_null_get_type ());
  91 }