HashSet.h

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 _DECAF_UTIL_HASHSET_H_
#define _DECAF_UTIL_HASHSET_H_

#include <decaf/util/Config.h>

#include <decaf/util/AbstractSet.h>
#include <decaf/util/HashMap.h>
#include <decaf/util/HashCode.h>
#include <decaf/lang/Pointer.h>
#include <decaf/lang/Integer.h>
#include <decaf/util/ConcurrentModificationException.h>
#include <decaf/lang/exceptions/UnsupportedOperationException.h>

namespace decaf {
namespace util {

    template<typename E, typename HASHCODE = HashCode<E> >
    class HashSet : public AbstractSet<E> {
    protected:

        HashMap<E, Set<E>*, HASHCODE>* backingMap;

    public:

        HashSet() : AbstractSet<E>(), backingMap(new HashMap<E, Set<E>*, HASHCODE>()) {}

        HashSet(int capacity) : AbstractSet<E>(), backingMap(new HashMap<E, Set<E>*, HASHCODE>(capacity)) {}

        HashSet(int capacity, float loadFactor) :
            AbstractSet<E>(), backingMap(new HashMap<E, Set<E>*, HASHCODE>(capacity, loadFactor)) {
        }

        HashSet(const Collection<E>& collection) : AbstractSet<E>(), backingMap() {

            this->backingMap = new HashMap<E, Set<E>*, HASHCODE>(
                (collection.size() < 6 ? 11 : collection.size() * 2));

            decaf::lang::Pointer<Iterator<E> > iter(collection.iterator());
            while (iter->hasNext()) {
                this->add(iter->next());
            }
        }

        HashSet(const HashSet<E>& collection) : AbstractCollection<E>(), AbstractSet<E>(), backingMap() {

            this->backingMap = new HashMap<E, Set<E>*, HASHCODE>(
                (collection.size() < 6 ? 11 : collection.size() * 2));

            decaf::lang::Pointer<Iterator<E> > iter(collection.iterator());
            while (iter->hasNext()) {
                this->add(iter->next());
            }
        }

        virtual ~HashSet() {
            try {
                delete this->backingMap;
            }
            DECAF_CATCHALL_NOTHROW()
        }

    protected:

        HashSet(HashMap<E, Set<E>*, HASHCODE>* backingMap) :
            AbstractSet<E>(), backingMap(backingMap) {
        }

    public:

        HashSet<E>& operator= (const Collection<E>& collection) {
            this->clear();
            this->addAll(collection);
            return *this;
        }

    public:

        virtual bool add(const E& value) {
            return this->backingMap->put(value, this);
        }

        virtual void clear() {
            this->backingMap->clear();
        }

        virtual bool contains(const E& value) const {
            return this->backingMap->containsKey(value);
        }

        virtual bool isEmpty() const {
            return this->backingMap->isEmpty();
        }

        virtual Iterator<E>* iterator() {
            return this->backingMap->keySet().iterator();
        }

        virtual Iterator<E>* iterator() const {
            return this->backingMap->keySet().iterator();
        }

        virtual bool remove(const E& value) {
            try {
                this->backingMap->remove(value);
            } catch(decaf::util::NoSuchElementException& ex) {
                return false;
            }

            return true;
        }

        virtual int size() const {
            return this->backingMap->size();
        }

        virtual std::string toString() const {

            std::string result;

            result.append("decaf::util::HashSet [  size = ");
            result.append(decaf::lang::Integer::toString(this->size()));
            result.append(" ]");

            return result;
        }

    };

}}

#endif /* _DECAF_UTIL_HASHSET_H_ */