camel/camel-seekable-stream.h

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2 /* camel-stream-fs.h :stream based on unix filesystem */
   3
   4 /*
   5  * Author:
   6  *  Bertrand Guiheneuf <bertrand@helixcode.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
  26 #ifndef CAMEL_SEEKABLE_STREAM_H
  27 #define CAMEL_SEEKABLE_STREAM_H 1
  28
  29 #include <sys/types.h>
  30 #include <unistd.h>
  31 #include <camel/camel-stream.h>
  32
  33 #define CAMEL_SEEKABLE_STREAM_TYPE     (camel_seekable_stream_get_type ())
  34 #define CAMEL_SEEKABLE_STREAM(obj)     (CAMEL_CHECK_CAST((obj), CAMEL_SEEKABLE_STREAM_TYPE, CamelSeekableStream))
  35 #define CAMEL_SEEKABLE_STREAM_CLASS(k) (CAMEL_CHECK_CLASS_CAST ((k), CAMEL_SEEKABLE_STREAM_TYPE, CamelSeekableStreamClass))
  36 #define CAMEL_IS_SEEKABLE_STREAM(o)    (CAMEL_CHECK_TYPE((o), CAMEL_SEEKABLE_STREAM_TYPE))
  37
  38 G_BEGIN_DECLS
  39
  40 typedef enum {
  41         CAMEL_STREAM_SET = SEEK_SET,
  42         CAMEL_STREAM_CUR = SEEK_CUR,
  43         CAMEL_STREAM_END = SEEK_END
  44 } CamelStreamSeekPolicy;
  45
  46 #define CAMEL_STREAM_UNBOUND (~0)
  47
  48 struct _CamelSeekableStream {
  49         CamelStream parent_object;
  50
  51         off_t position;         /* current postion in the stream */
  52         off_t bound_start;      /* first valid position */
  53         off_t bound_end;        /* first invalid position */
  54 };
  55
  56 typedef struct {
  57         CamelStreamClass parent_class;
  58
  59         /* Virtual methods */
  60         off_t (*seek)       (CamelSeekableStream *stream, off_t offset,
  61                              CamelStreamSeekPolicy policy);
  62         off_t (*tell)       (CamelSeekableStream *stream);
  63         int  (*set_bounds)  (CamelSeekableStream *stream,
  64                              off_t start, off_t end);
  65 } CamelSeekableStreamClass;
  66
  67 /* Standard Camel function */
  68 CamelType camel_seekable_stream_get_type (void);
  69
  70 /* public methods */
  71 off_t    camel_seekable_stream_seek            (CamelSeekableStream *stream, off_t offset,
  72                                                 CamelStreamSeekPolicy policy);
  73 off_t    camel_seekable_stream_tell            (CamelSeekableStream *stream);
  74 int      camel_seekable_stream_set_bounds      (CamelSeekableStream *stream, off_t start, off_t end);
  75
  76 G_END_DECLS
  77
  78 #endif /* CAMEL_SEEKABLE_STREAM_H */