Filter.c

/*
Copyright (C) <2010-2011> Karl Hiramoto <karl@hiramoto.org>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#include <stdlib.h>
#include <errno.h>

#ifdef HAVE_CONFIG_H
#include "nfq-web-filter-config.h"
#endif


#include "Filter.h"
#include "nfq_wf_private.h"

/**
* @ingroup FilterObject
* @{
*/

static struct Filter_ops *get_fobj_ops(struct Filter *fobj)
{
	if (!fobj->fo_ops)
		BUG();

	return fobj->fo_ops;
}

#if 0
static struct Object_ops *get_obj_ops(struct Filter *fobj)
{

	if (!fobj->obj_ops)
		BUG();

	return fobj->obj_ops;
}
#endif

/**
 * Allocate a new object of kind specified by the operations handle
 * @arg ops		operations handle
 * @return The new object or NULL
 */
struct Filter *Filter_alloc(struct Filter_ops *fo_ops)
{
	struct Filter *new_filter;
	struct Object_ops *obj_ops = fo_ops->ops;

	if (obj_ops->obj_size < sizeof(*new_filter))
		BUG();

	new_filter = (struct Filter *) Object_alloc(obj_ops);
	if (!new_filter)
		return NULL;

	DBG(4, "Allocated new filter object %p\n", new_filter);

	new_filter->fo_ops = fo_ops;
	if (fo_ops->foo_constructor) {
		DBG(4, "New filter object %p has constructor\n", new_filter);
		fo_ops->foo_constructor(new_filter);
	}

	return new_filter;
}


void Filter_free(struct Filter **obj_in)
{
	struct Filter *obj; /* just used to de-reference input arg */
	struct Filter_ops *fops;
	if (!obj_in || !*obj_in)
		return;

	obj = *obj_in;
	fops = get_fobj_ops(obj);


	if (obj->refcount > 0)
		DBG(1, "Warning: Freeing object in use... refcount=%d\n", obj->refcount);

	/* Call this objects desctructor */
	if (fops->foo_destructor)
		fops->foo_destructor(obj);

	DBG(4, "Freed filter object %p\n", obj);

	/* call parents destructor */
	Object_free((struct Object**)obj_in);
}

/**
* @name Reference Management
* @{
*/

/**
* Acquire a reference on a object
* @arg obj  	object to acquire reference from
*/
void Filter_get(struct Filter *obj)
{
	obj->refcount++;
	DBG(4, "New reference to filter object '%s' %p, total refcount %d\n",
		obj->fo_ops->ops->obj_type, obj, obj->refcount);
}

/**
* Release a reference from an object
* @arg obj		object to release reference from
*/
void Filter_put(struct Filter **obj_in)
{
	struct Filter *obj;

	if (!obj_in || !*obj_in)
		return;

 	obj = *obj_in;

	obj->refcount--;
	DBG(4, "Returned object reference '%s' %p, %d remaining\n",
		obj->fo_ops->ops->obj_type, obj, obj->refcount);

	if (obj->refcount < 0)
		BUG();

	if (obj->refcount <= 0)
 		Filter_free(obj_in);
}


bool Filter_shared(struct Filter *obj)
{
	return obj->refcount > 1;
}

int Filter_fromXml(struct Filter *fo, xmlNode *node)
{
	xmlChar *prop = NULL;
	struct Filter_ops *ops = get_fobj_ops(fo);
	unsigned int id;
	int ret;

	if (!ops->foo_load_from_xml) {
		DBG(1, "Invalid object does not have load XML operation\n");
		return -EINVAL;
	}
	DBG(5, "Calling load XML operation\n");

	prop = xmlGetProp(node, BAD_CAST FILTER_ID_XML_PROP);
	if (!prop) {
		ERROR(" filter objects MUST have '%s' XML props \n", FILTER_ID_XML_PROP);
		return -1;
	}

	ret = sscanf((char *) prop, "%u", &id);
	if (ret < 1) {
		ERROR(" Parsing %s\n", FILTER_ID_XML_PROP);
	}
	Filter_setFilterId(fo, id);
	DBG(5, " %s = %s = %u = %u\n", FILTER_ID_XML_PROP, prop, Filter_getFilterId(fo), id);

	xmlFree(prop);

	return ops->foo_load_from_xml(fo, node);
}

/** @} */