/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-stream-fs.c : file system based stream */
/* inspired by gnome-stream-fs.c in bonobo by Miguel de Icaza */
/*
*
* Author :
* Bertrand Guiheneuf <bertrand@helixcode.com>
*
* Copyright 1999, 2000 HelixCode (http://www.helixcode.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
*/
#include <config.h>
#include "camel-seekable-substream.h"
#include "camel-log.h"
static CamelSeekableStreamClass *parent_class=NULL;
/* Returns the class for a CamelSeekableSubStream */
#define CSS_CLASS(so) CAMEL_SEEKABLE_SUBSTREAM_CLASS (GTK_OBJECT(so)->klass)
static gint _read (CamelStream *stream,
gchar *buffer, gint n);
static gint _write (CamelStream *stream,
const gchar *buffer,
gint n);
static void _flush (CamelStream *stream);
static gint _available (CamelStream *stream);
static gboolean _eos (CamelStream *stream);
static void _close (CamelStream *stream);
static gint _seek (CamelSeekableStream *stream,
gint offset,
CamelStreamSeekPolicy policy);
static void _finalize (GtkObject *object);
static void _destroy (GtkObject *object);
static void _init_with_seekable_stream_and_bounds (CamelSeekableSubstream *seekable_substream,
CamelSeekableStream *parent_stream,
guint32 inf_bound,
guint32 sup_bound);
static void
camel_seekable_substream_class_init (CamelSeekableSubstreamClass *camel_seekable_substream_class)
{
CamelSeekableStreamClass *camel_seekable_stream_class = CAMEL_SEEKABLE_STREAM_CLASS (camel_seekable_substream_class);
CamelStreamClass *camel_stream_class = CAMEL_STREAM_CLASS (camel_seekable_substream_class);
GtkObjectClass *gtk_object_class = GTK_OBJECT_CLASS (camel_seekable_substream_class);
parent_class = gtk_type_class (camel_seekable_stream_get_type ());
/* virtual method definition */
camel_seekable_substream_class->init_with_seekable_stream_and_bounds = _init_with_seekable_stream_and_bounds;
/* virtual method overload */
camel_stream_class->read = _read;
camel_stream_class->write = _write;
camel_stream_class->flush = _flush;
camel_stream_class->available = _available;
camel_stream_class->eos = _eos;
camel_stream_class->close = _close;
camel_seekable_stream_class->seek = _seek;
gtk_object_class->finalize = _finalize;
gtk_object_class->destroy = _destroy;
}
static void
camel_seekable_substream_init (gpointer object, gpointer klass)
{
/* does nothing */
}
GtkType
camel_seekable_substream_get_type (void)
{
static GtkType camel_seekable_substream_type = 0;
if (!camel_seekable_substream_type) {
GtkTypeInfo camel_seekable_substream_info =
{
"CamelSeekableSubstream",
sizeof (CamelSeekableSubstream),
sizeof (CamelSeekableSubstreamClass),
(GtkClassInitFunc) camel_seekable_substream_class_init,
(GtkObjectInitFunc) camel_seekable_substream_init,
/* reserved_1 */ NULL,
/* reserved_2 */ NULL,
(GtkClassInitFunc) NULL,
};
camel_seekable_substream_type = gtk_type_unique (camel_seekable_stream_get_type (), &camel_seekable_substream_info);
}
return camel_seekable_substream_type;
}
static void
_destroy (GtkObject *object)
{
CAMEL_LOG_FULL_DEBUG ("Entering CamelSeekableSubstream::destroy\n");
/* does nothing for the moment */
GTK_OBJECT_CLASS (parent_class)->destroy (object);
CAMEL_LOG_FULL_DEBUG ("Leaving CamelSeekableSubstream::destroy\n");
}
static void
_finalize (GtkObject *object)
{
CAMEL_LOG_FULL_DEBUG ("Entering CamelSeekableSubstream::finalize\n");
/* does nothing for the moment */
GTK_OBJECT_CLASS (parent_class)->finalize (object);
CAMEL_LOG_FULL_DEBUG ("Leaving CamelSeekableSubstream::finalize\n");
}
static void
_set_bounds (CamelSeekableSubstream *seekable_substream, guint32 inf_bound, guint32 sup_bound)
{
CAMEL_LOG_FULL_DEBUG ("CamelSeekableSubstream::_set_bounds entering\n");
g_assert (seekable_substream);
g_assert (seekable_substream->parent_stream);
/* store the bounds */
seekable_substream->inf_bound = inf_bound;
seekable_substream->sup_bound = sup_bound;
/* go to the first position */
camel_seekable_stream_seek (seekable_substream->parent_stream, inf_bound, SEEK_SET);
seekable_substream->cur_pos = inf_bound;
CAMEL_LOG_FULL_DEBUG ("In CamelSeekableSubstream::_set_bounds, "
"setting inf bound to %u, "
"sup bound to %ld, current postion to %u from %u\n",
seekable_substream->inf_bound, seekable_substream->sup_bound,
seekable_substream->cur_pos, inf_bound);
CAMEL_LOG_FULL_DEBUG ("CamelSeekableSubstream::_set_bounds Leaving\n");
}
static void
_init_with_seekable_stream_and_bounds (CamelSeekableSubstream *seekable_substream,
CamelSeekableStream *parent_stream,
guint32 inf_bound,
guint32 sup_bound)
{
/* sanity checks */
g_assert (seekable_substream);
g_assert (!seekable_substream->parent_stream);
g_assert (parent_stream);
/* store the parent stream */
seekable_substream->parent_stream = parent_stream;
/* set the bound of the substream */
_set_bounds (seekable_substream, inf_bound, sup_bound);
}
void
camel_seekable_substream_init_with_seekable_stream_and_bounds (CamelSeekableSubstream *seekable_substream,
CamelSeekableStream *parent_stream,
guint32 inf_bound,
guint32 sup_bound)
{
CSS_CLASS (seekable_substream)->init_with_seekable_stream_and_bounds (seekable_substream,
parent_stream,
inf_bound,
sup_bound);
}
/**
* _read: read bytes from a stream
* @stream: stream
* @buffer: buffer where bytes are stored
* @n: max number of bytes to read
*
*
*
* Return value: number of bytes actually read.
**/
static gint
_read (CamelStream *stream, gchar *buffer, gint n)
{
CamelSeekableStream *seekable_stream = CAMEL_SEEKABLE_STREAM (stream);
CamelSeekableSubstream *seekable_substream = CAMEL_SEEKABLE_SUBSTREAM (stream);
gint v;
gint nb_to_read;
guint32 parent_stream_current_position;
guint32 position_in_parent;
g_assert (stream);
g_assert (seekable_substream->parent_stream);
g_assert (seekable_substream->open);
/*
we are doing something quite infefficient :
each time we want to read a block, we store
the parent stream position so that we can
change it, and restore it before returning
This may change. I don't know yet.
It may be useless to reseek every time
and is incompatible with buffering.
*/
parent_stream_current_position =
camel_seekable_stream_get_current_position (seekable_substream->parent_stream);
/* compute the position in the parent stream */
position_in_parent =
seekable_stream->cur_pos + seekable_substream->inf_bound;
/* go to our position in the parent stream */
camel_seekable_stream_seek (seekable_substream->parent_stream,
position_in_parent,
CAMEL_STREAM_SET);
/* compute how much byte should be read */
nb_to_read =
MIN (seekable_substream->sup_bound - position_in_parent, n);
/* Read the data */
if (nb_to_read >0 )
v = camel_stream_read ( CAMEL_STREAM (seekable_substream->parent_stream),
buffer,
nb_to_read);
else
v = 0;
/* if the return value is negative, an error occured,
we must do something FIXME : handle exception */
if (v<0)
CAMEL_LOG_FULL_DEBUG ("CamelSeekableSubstream::read v=%d\n", v);
else
seekable_stream->cur_pos += v;
/* restore the parent position */
camel_seekable_stream_seek (seekable_substream->parent_stream,
parent_stream_current_position,
CAMEL_STREAM_SET);
/* return the number of bytes read */
return v;
}
/**
* _write: write bytes to a stream
* @stream: the stream
* @buffer: byte buffer
* @n: number of bytes to write
*
*
*
* Return value: the number of bytes actually written
* in the stream.
**/
static gint
_write (CamelStream *stream, const gchar *buffer, gint n)
{
/* NOT VALID ON SEEKABLE SUBSTREAM */
g_warning ("CamelSeekableSubstream:: seekable substream don't have a write method\n");
CAMEL_LOG_WARNING ( "CamelSeekableSubstream:: seekable substream don't have a write method\n");
return -1;
}
/**
* _flush: flush pending changes
* @stream: the stream
*
*
**/
static void
_flush (CamelStream *stream)
{
/* NOT VALID ON SEEKABLE SUBSTREAM */
g_warning ("CamelSeekableSubstream:: seekable substream don't have a flush method\n");
CAMEL_LOG_WARNING ( "CamelSeekableSubstream:: seekable substream don't have a flush method\n");
}
/**
* _available: return the number of bytes available for reading
* @stream: the stream
*
* Return the number of bytes available without blocking.
*
* Return value: the number of bytes available
**/
static gint
_available (CamelStream *stream)
{
g_warning ("not implemented\n");
return -1;
}
/**
* _eos: test if there are bytes left to read
* @stream: the stream
*
*
*
* Return value: true if all stream has been read
**/
static gboolean
_eos (CamelStream *stream)
{
CamelSeekableSubstream *seekable_substream = CAMEL_SEEKABLE_SUBSTREAM (stream);
CamelSeekableStream *seekable_stream = CAMEL_SEEKABLE_STREAM (stream);
guint32 substream_len;
g_assert (stream);
g_assert (seekable_substream->open);
substream_len = seekable_substream->sup_bound - seekable_substream->inf_bound;
return ( seekable_stream->cur_pos > substream_len);
}
/**
* _close: close a stream
* @stream: the stream
*
*
**/
static void
_close (CamelStream *stream)
{
CamelSeekableSubstream *seekable_substream = CAMEL_SEEKABLE_SUBSTREAM (stream);
g_assert (stream);
seekable_substream->open = FALSE;
}
static gint
_seek (CamelSeekableStream *stream, gint offset, CamelStreamSeekPolicy policy)
{
CamelSeekableSubstream *seekable_substream = CAMEL_SEEKABLE_SUBSTREAM (stream);
CamelSeekableStream *seekable_stream = CAMEL_SEEKABLE_STREAM (stream);
gint64 real_offset;
guint32 substream_len;
substream_len = seekable_substream->sup_bound - seekable_substream->inf_bound;
switch (policy) {
case CAMEL_STREAM_SET:
real_offset = offset;
break;
case CAMEL_STREAM_CUR:
real_offset = seekable_stream->cur_pos + offset;
break;
case CAMEL_STREAM_END:
real_offset = substream_len - offset;
break;
default:
return -1;
}
if (real_offset > 0) {
seekable_stream->cur_pos = MIN (real_offset, substream_len);
} else
seekable_stream->cur_pos = 0;
return seekable_stream->cur_pos;
}
