/* Delta objects generic implementation */
/* $Id: delta.c,v 1.5 2003/07/31 18:28:13 pasky Exp $ */

/*
 * Copyright (c) 2003  Petr Baudis.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials
 *     provided with the distribution.
 *   * Neither the name of the author nor the names of the product's
 *     contributors may be used to endorse or promote products
 *     derived from this software without specific prior written
 *     permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include <librev/dataobj.h>
#include <librev/delta.h>
#include <librev/librev.h>


struct rev_delta *
rev_delta_init ()
{
	struct rev_delta *obj = calloc (1, sizeof (struct rev_delta));

	return obj;
}

void
rev_delta_done (struct rev_delta *obj)
{
	assert (obj && ! obj->refcount);

	if (obj->udata && obj->userops && obj->userops->done)
		obj->userops->done (obj);
	if (obj->data && obj->dataops && obj->dataops->done)
		obj->dataops->done (obj);

	rev_delta_set_dataobj1 (obj, NULL);
	rev_delta_set_dataobj2 (obj, NULL);

	rev_delta_set_filename1 (obj, NULL);
	rev_delta_set_filename2 (obj, NULL);

	free (obj);
}

int
rev_delta_diff (struct rev_delta *obj)
{
	int res;

	assert (obj);

	if (! obj->dataobj1 || ! obj->dataobj2)
		return 0;

	if (obj->data && obj->dataops && obj->dataops->diff) {
		res = obj->dataops->diff (obj);
		if (res < 0) return res;
	}

	rev_delta_set_filename1 (obj, obj->dataobj1->filename);
	rev_delta_set_filename2 (obj, obj->dataobj2->filename);

	return res;
}

int
rev_delta_apply (struct rev_delta *obj)
{
	int res;

	assert (obj);

	if (! obj->dataobj1)
		return 0;

	if (obj->data && obj->dataops && obj->dataops->apply) {
		res = obj->dataops->apply (obj);
		if (res < 0) return res;
	}

	if (! obj->dataobj2)
		rev_delta_set_dataobj2 (obj, rev_dataobj_init ());
	if (! obj->dataobj2)
		return -1;

	if (obj->filename2)
		rev_dataobj_set_filename (obj->dataobj2, obj->filename2);

	return res;
}

int
rev_delta_unapply (struct rev_delta *obj)
{
	int res;

	assert (obj);

	if (! obj->dataobj2 || ! obj->filename1)
		return 0;

	if (obj->data && obj->dataops && obj->dataops->unapply) {
		res = obj->dataops->unapply (obj);
		if (res < 0) return res;
	}

	if (! obj->dataobj1)
		rev_delta_set_dataobj1 (obj, rev_dataobj_init ());
	if (! obj->dataobj1)
		return -1;

	if (obj->filename1)
		rev_dataobj_set_filename (obj->dataobj1, obj->filename1);

	return res;
}