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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
* Author:
* Bertrand Guiheneuf <bertrand@helixcode.com>
*
* Copyright 1999, 2000 Ximian, Inc. (www.ximian.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "camel-seekable-stream.h"
static CamelStreamClass *parent_class = NULL;
/* Returns the class for a CamelSeekableStream */
#define CSS_CLASS(so) CAMEL_SEEKABLE_STREAM_CLASS (CAMEL_OBJECT_GET_CLASS(so))
static off_t seek (CamelSeekableStream *stream, off_t offset,
CamelStreamSeekPolicy policy);
static off_t stream_tell (CamelSeekableStream *stream);
static int reset (CamelStream *stream);
static int set_bounds (CamelSeekableStream *stream, off_t start, off_t end);
static void
camel_seekable_stream_class_init (CamelSeekableStreamClass *camel_seekable_stream_class)
{
CamelStreamClass *camel_stream_class =
CAMEL_STREAM_CLASS (camel_seekable_stream_class);
parent_class = CAMEL_STREAM_CLASS( camel_type_get_global_classfuncs( CAMEL_STREAM_TYPE ) );
/* seekable stream methods */
camel_seekable_stream_class->seek = seek;
camel_seekable_stream_class->tell = stream_tell;
camel_seekable_stream_class->set_bounds = set_bounds;
/* camel stream methods overload */
camel_stream_class->reset = reset;
}
static void
camel_seekable_stream_init (void *o)
{
CamelSeekableStream *stream = (CamelSeekableStream *)o;
stream->bound_start = 0;
stream->bound_end = CAMEL_STREAM_UNBOUND;
}
CamelType
camel_seekable_stream_get_type (void)
{
static CamelType camel_seekable_stream_type = CAMEL_INVALID_TYPE;
if (camel_seekable_stream_type == CAMEL_INVALID_TYPE) {
camel_seekable_stream_type = camel_type_register( CAMEL_STREAM_TYPE,
"CamelSeekableStream",
sizeof( CamelSeekableStream ),
sizeof( CamelSeekableStreamClass ),
(CamelObjectClassInitFunc) camel_seekable_stream_class_init,
NULL,
(CamelObjectInitFunc) camel_seekable_stream_init,
NULL );
}
return camel_seekable_stream_type;
}
static off_t
seek (CamelSeekableStream *stream, off_t offset,
CamelStreamSeekPolicy policy)
{
g_warning ("CamelSeekableStream::seek called on default "
"implementation\n");
return -1;
}
/**
* camel_stream_seek:
* @stream: a CamelStream object.
* @offset: offset value
* @policy: what to do with the offset
*
* Seek to the specified position in @stream.
*
* If @policy is CAMEL_STREAM_SET, seeks to @offset.
*
* If @policy is CAMEL_STREAM_CUR, seeks to the current position plus
* @offset.
*
* If @policy is CAMEL_STREAM_END, seeks to the end of the stream plus
* @offset.
*
* Regardless of @policy, the stream's final position will be clamped
* to the range specified by its lower and upper bounds, and the
* stream's eos state will be updated.
*
* Return value: new position, -1 if operation failed.
**/
off_t
camel_seekable_stream_seek (CamelSeekableStream *stream, off_t offset,
CamelStreamSeekPolicy policy)
{
g_return_val_if_fail (CAMEL_IS_SEEKABLE_STREAM (stream), -1);
return CSS_CLASS (stream)->seek (stream, offset, policy);
}
static off_t
stream_tell (CamelSeekableStream *stream)
{
return stream->position;
}
/**
* camel_seekable_stream_tell:
* @stream: seekable stream object
*
* Get the current position of a seekable stream.
*
* Return value: the position.
**/
off_t
camel_seekable_stream_tell (CamelSeekableStream *stream)
{
g_return_val_if_fail (CAMEL_IS_SEEKABLE_STREAM (stream), -1);
return CSS_CLASS (stream)->tell (stream);
}
static int
set_bounds (CamelSeekableStream *stream, off_t start, off_t end)
{
/* store the bounds */
stream->bound_start = start;
stream->bound_end = end;
if (start > stream->position)
return camel_seekable_stream_seek (stream, start, CAMEL_STREAM_SET);
return 0;
}
/**
* camel_seekable_stream_set_bounds:
* @stream: a seekable stream
* @start: the first valid position
* @end: the first invalid position, or CAMEL_STREAM_UNBOUND
*
* Set the range of valid data this stream is allowed to cover. If
* there is to be no @end value, then @end should be set to
* #CAMEL_STREAM_UNBOUND.
*
* Return value: -1 on error.
**/
int
camel_seekable_stream_set_bounds (CamelSeekableStream *stream,
off_t start, off_t end)
{
g_return_val_if_fail (CAMEL_IS_SEEKABLE_STREAM (stream), -1);
g_return_val_if_fail (end == CAMEL_STREAM_UNBOUND || end >= start, -1);
return CSS_CLASS (stream)->set_bounds (stream, start, end);
}
/* a default implementation of reset for seekable streams */
static int
reset (CamelStream *stream)
{
CamelSeekableStream *seekable_stream;
seekable_stream = CAMEL_SEEKABLE_STREAM (stream);
return camel_seekable_stream_seek (seekable_stream,
seekable_stream->bound_start,
CAMEL_STREAM_SET);
}
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