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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "glk/adrift/scare.h"
#include "glk/adrift/sxprotos.h"
namespace Glk {
namespace Adrift {
/*
* Structure for representing a fake game save/restore file. Used to catch
* a serialized gamestate, and return it later on restore. For now we allow
* only one of these to exist.
*/
struct sx_scr_stream_t {
sc_byte *data;
sc_int length;
sc_bool is_open;
sc_bool is_writable;
};
static sx_scr_stream_t scr_serialization_stream = {NULL, 0, FALSE, FALSE};
/*
* file_open_file_callback()
* file_read_file_callback()
* file_write_file_callback()
* file_close_file_callback()
*
* Fake a single gamestate save/restore file. Used to satisfy requests from
* the script to serialize and restore a gamestate. Only one "file" can
* exist, meaning that a script must restore a saved game before trying to
* save another.
*/
void *file_open_file_callback (sc_bool is_save)
{
sx_scr_stream_t *const stream = &scr_serialization_stream;
/* Detect any problems due to scripting limitations. */
if (stream->is_open)
{
scr_test_failed ("File open error: %s",
"stream is in use (script limitation)");
return NULL;
}
else if (is_save && stream->data)
{
scr_test_failed ("File open error: %s",
"stream has not been read (script limitation)");
return NULL;
}
/*
* Set up the stream for the requested mode. Act as if no such file if
* no data available for a read-only open.
*/
if (is_save)
{
stream->data = NULL;
stream->length = 0;
}
else if (!stream->data)
return NULL;
stream->is_open = TRUE;
stream->is_writable = is_save;
return stream;
}
sc_int
file_read_file_callback (void *opaque, sc_byte *buffer, sc_int length)
{
sx_scr_stream_t *const stream = (sx_scr_stream_t *)opaque;
sc_int bytes;
assert (opaque && buffer && length > 0);
/* Detect any problems with the callback parameters. */
if (stream != &scr_serialization_stream)
{
scr_test_failed ("File read error: %s", "stream is invalid");
return 0;
}
else if (!stream->is_open)
{
scr_test_failed ("File read error: %s", "stream is not open");
return 0;
}
else if (stream->is_writable)
{
scr_test_failed ("File read error: %s", "stream is not open for read");
return 0;
}
/* Read and remove the first block of data (or all if less than length). */
bytes = (stream->length < length) ? stream->length : length;
memcpy (buffer, stream->data, bytes);
memmove (stream->data, stream->data + bytes, stream->length - bytes);
stream->length -= bytes;
return bytes;
}
void
file_write_file_callback (void *opaque, const sc_byte *buffer, sc_int length)
{
sx_scr_stream_t *const stream = (sx_scr_stream_t *)opaque;
assert (opaque && buffer && length > 0);
/* Detect any problems with the callback parameters. */
if (stream != &scr_serialization_stream)
{
scr_test_failed ("File write error: %s", "stream is invalid");
return;
}
else if (!stream->is_open)
{
scr_test_failed ("File write error: %s", "stream is not open");
return;
}
else if (!stream->is_writable)
{
scr_test_failed ("File write error: %s", "stream is not open for write");
return;
}
/* Reallocate, then add this block of data to the buffer. */
stream->data = (sc_byte *)sx_realloc(stream->data, stream->length + length);
memcpy (stream->data + stream->length, buffer, length);
stream->length += length;
}
void
file_close_file_callback (void *opaque)
{
sx_scr_stream_t *const stream = (sx_scr_stream_t *)opaque;
assert (opaque);
/* Detect any problems with the callback parameters. */
if (stream != &scr_serialization_stream)
{
scr_test_failed ("File close error: %s", "stream is invalid");
return;
}
else if (!stream->is_open)
{
scr_test_failed ("File close error: %s", "stream is not open");
return;
}
/*
* If closing after a read, free allocations, and return the stream to
* its empty state; if after write, leave the data for the later read.
*/
if (!stream->is_writable)
{
sx_free (stream->data);
stream->data = NULL;
stream->length = 0;
}
stream->is_writable = FALSE;
stream->is_open = FALSE;
}
/*
* file_cleanup()
*
* Free any pending allocations and clean up on completion of a script.
*/
void
file_cleanup (void)
{
sx_scr_stream_t *const stream = &scr_serialization_stream;
sx_free (stream->data);
stream->data = NULL;
stream->length = 0;
stream->is_writable = FALSE;
stream->is_open = FALSE;
}
} // End of namespace Adrift
} // End of namespace Glk
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