EqualsAttributeFilter.h

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/*
 Copyright (2016) Michael Baer, Daniel Bonrath, All rights reserved.

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

#ifndef __M2ETIS_PUBSUB_FILTER_FILTEREXPRESSIONS_EQUALSATTRIBUTEFILTER_H__
#define __M2ETIS_PUBSUB_FILTER_FILTEREXPRESSIONS_EQUALSATTRIBUTEFILTER_H__

#include "m2etis/pubsub/filter/filterexpressions/AttributeFilter.h"
#include "m2etis/pubsub/filter/filtervisitors/FilterVisitor.h"

namespace m2etis {
namespace pubsub {
namespace filter {

        template<typename EventType, typename AttributeType> class AttributeFilter;
        template<typename EventType, typename AttributeType> class NotEqualsAttributeFilter;
        template<typename EventType, typename AttributeType> class GreaterThanAttributeFilter;
        template<typename EventType, typename AttributeType> class LessThanAttributeFilter;

        template<typename EventType, typename AttributeType>
        class EqualsAttributeFilter : public AttributeFilter<EventType, AttributeType> {
        public:
                typedef EventType schema; // needed for operator overloading FIXME: (Daniel) really? never used or I don't see it
                EqualsAttributeFilter() : AttributeFilter<EventType, AttributeType>(-1, {})  {} // needed for boost serialization
                EqualsAttributeFilter(const AttributeName attribute_id, const AttributeType & constants) : AttributeFilter<EventType, AttributeType>(attribute_id, {constants}) {}
                virtual ~EqualsAttributeFilter() {}

                // function called to match against an event
                virtual bool matchAttribute(const AttributeType & attribute) const override {
                        return attribute == this->get_constants()[0]; // attribute type has to implement "=="-operator
                }

                using AttributeFilter<EventType, AttributeType>::overlaps;

                virtual void getAttributeType(FilterVisitor<EventType> & visitor) const override {
                        visitor.getAttributeType(this);
                }

                virtual bool overlaps(const AttributeFilter<EventType, AttributeType> * other_filter) const override {
                        if (this->get_attribute_id() != other_filter->get_attribute_id()) {
                                return true; // AttributeFilters for different attributes overlap
                        }
                        if (typeid(EqualsAttributeFilter<EventType, AttributeType>) == typeid(*other_filter)) {
                                return this->get_constants()[0] == other_filter->get_constants()[0];
                        }
                        if (typeid(NotEqualsAttributeFilter<EventType, AttributeType>) == typeid(*other_filter)) {
                                return this->get_constants()[0] != other_filter->get_constants()[0];
                        }
                        if (typeid(GreaterThanAttributeFilter<EventType, AttributeType>) == typeid(*other_filter)) {
                                return this->get_constants()[0] > other_filter->get_constants()[0];
                        }
                        if (typeid(LessThanAttributeFilter<EventType, AttributeType>) == typeid(*other_filter)) {
                                return this->get_constants()[0] < other_filter->get_constants()[0];
                        }

                        return true;
                } // overlaps()

        private:
                friend class boost::serialization::access; // not sure if necessary
                template<typename Archive>
                void serialize(Archive & ar, const unsigned int) {
                        ar & boost::serialization::base_object<AttributeFilter<EventType, AttributeType>>(*this);
                }
        }; // EqualsAttributeFilter

} /* namespace filter */
} /* namespace pubsub */
} /* namespace m2etis */

#endif /* __M2ETIS_PUBSUB_FILTER_FILTEREXPRESSIONS_EQUALSATTRIBUTEFILTER_H__ */