com.b2international.collections.objects.ObjectKeyLongMapWrapper.java Source code

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Here is the source code for com.b2international.collections.objects.ObjectKeyLongMapWrapper.java

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/*
 * Copyright 2011-2016 B2i Healthcare Pte Ltd, http://b2i.sg
 * 
 * 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.
 */
package com.b2international.collections.objects;

import java.util.Iterator;
import java.util.Set;

import com.b2international.collections.longs.LongCollection;
import com.b2international.collections.longs.LongCollectionWrapper;
import com.b2international.collections.longs.LongValueMap;
import com.google.common.primitives.Longs;

import it.unimi.dsi.fastutil.objects.Object2LongMap;
import it.unimi.dsi.fastutil.objects.Object2LongOpenCustomHashMap;
import it.unimi.dsi.fastutil.objects.Object2LongOpenHashMap;

/**
 * @since 4.7
 */
public final class ObjectKeyLongMapWrapper<K> implements LongValueMap<K> {

    private final Object2LongMap<K> delegate;

    private ObjectKeyLongMapWrapper(Object2LongMap<K> delegate) {
        this.delegate = delegate;
    }

    @Override
    public int hashCode() {
        int h = 0;
        final Iterator<K> i = keySet().iterator();
        while (i.hasNext()) {
            K key = i.next();
            long value = get(key);
            h += (key == null ? 0 : key.hashCode()) ^ Longs.hashCode(value);
        }
        return h;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (!(obj instanceof LongValueMap))
            return false;

        try {
            final LongValueMap<K> other = (LongValueMap<K>) obj;
            if (other.size() != size())
                return false;

            final Iterator<K> i = keySet().iterator();
            while (i.hasNext()) {
                K key = i.next();
                long value = get(key);
                if (value != other.get(key)) {
                    return false;
                }
            }
        } catch (ClassCastException e) {
            return false;
        }

        return true;
    }

    @Override
    public void clear() {
        delegate.clear();
    }

    @Override
    public boolean isEmpty() {
        return delegate.isEmpty();
    }

    @Override
    public int size() {
        return delegate.size();
    }

    @Override
    public void trimToSize() {
        trim(delegate);
    }

    @Override
    public boolean containsKey(K key) {
        return delegate.containsKey(key);
    }

    @Override
    public long get(K key) {
        return delegate.getLong(key);
    }

    @Override
    public Set<K> keySet() {
        return delegate.keySet();
    }

    @Override
    public long put(K key, long value) {
        return delegate.put(key, value);
    }

    @Override
    public long remove(K key) {
        return delegate.removeLong(key);
    }

    @Override
    public LongCollection values() {
        return LongCollectionWrapper.wrap(delegate.values());
    }

    // Builder methods

    public static <K> LongValueMap<K> create(LongValueMap<K> map) {
        if (map instanceof ObjectKeyLongMapWrapper) {
            final Object2LongMap<K> sourceDelegate = ((ObjectKeyLongMapWrapper<K>) map).delegate;
            return new ObjectKeyLongMapWrapper<>(clone(sourceDelegate));
        } else {
            final LongValueMap<K> result = createWithExpectedSize(map.size());
            final Iterator<K> keys = map.keySet().iterator();
            while (keys.hasNext()) {
                final K key = keys.next();
                result.put(key, map.get(key));
            }
            return result;
        }
    }

    public static <K> LongValueMap<K> createWithExpectedSize(int expectedSize) {
        return new ObjectKeyLongMapWrapper<>(new Object2LongOpenHashMap<K>(expectedSize));
    }

    public static <K> LongValueMap<K> create() {
        return new ObjectKeyLongMapWrapper<>(new Object2LongOpenHashMap<K>());
    }

    // FastUtil helpers

    private static <K> Object2LongMap<K> clone(Object2LongMap<K> map) {
        if (map instanceof Object2LongOpenHashMap) {
            return ((Object2LongOpenHashMap<K>) map).clone();
        } else if (map instanceof Object2LongOpenCustomHashMap) {
            return ((Object2LongOpenCustomHashMap<K>) map).clone();
        } else {
            throw new UnsupportedOperationException(
                    "Unsupported map implementation: " + map.getClass().getSimpleName());
        }
    }

    private static <K> void trim(Object2LongMap<K> map) {
        if (map instanceof Object2LongOpenHashMap) {
            ((Object2LongOpenHashMap<K>) map).trim();
        } else if (map instanceof Object2LongOpenCustomHashMap) {
            ((Object2LongOpenCustomHashMap<K>) map).trim();
        } else {
            throw new UnsupportedOperationException(
                    "Unsupported map implementation: " + map.getClass().getSimpleName());
        }
    }

}