/*
 * Copyright (C) 2007 The Guava Authors
 *
 * 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 org.glassfish.jersey.internal.guava;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

Implementation of Multimap using hash tables. 

The multimap does not store duplicate key-value pairs. Adding a new
key-value pair equal to an existing key-value pair has no effect.

Keys and values may be null. All optional multimap methods are supported,
and all returned views are modifiable.

This class is not threadsafe when any concurrent operations update the multimap. Concurrent read operations will work correctly. To allow concurrent update operations, wrap your multimap with a call to Multimaps.synchronizedSetMultimap. 
Author:
Jared Levy
Since:
2.0 (imported from Google Collections Library)/**
 * Implementation of {@link Multimap} using hash tables.
 * <p>
 * <p>The multimap does not store duplicate key-value pairs. Adding a new
 * key-value pair equal to an existing key-value pair has no effect.
 * <p>
 * <p>Keys and values may be null. All optional multimap methods are supported,
 * and all returned views are modifiable.
 * <p>
 * <p>This class is not threadsafe when any concurrent operations update the
 * multimap. Concurrent read operations will work correctly. To allow concurrent
 * update operations, wrap your multimap with a call to {@link
 * Multimaps#synchronizedSetMultimap}.
 *
 * @author Jared Levy
 * @since 2.0 (imported from Google Collections Library)
 */
public final class HashMultimap<K, V> extends AbstractSetMultimap<K, V> {
    private static final int DEFAULT_VALUES_PER_KEY = 2;
    private static final long serialVersionUID = 0;
    private transient int expectedValuesPerKey = DEFAULT_VALUES_PER_KEY;

    private HashMultimap() {
        super(new HashMap<K, Collection<V>>());
    }

    
Creates a new, empty HashMultimap with the default initial capacities. /**
     * Creates a new, empty {@code HashMultimap} with the default initial
     * capacities.
     */
    public static <K, V> HashMultimap<K, V> create() {
        return new HashMultimap<K, V>();
    }

    
{@inheritDoc}

Creates an empty HashSet for a collection of values for one key. 
Returns:
a new HashSet containing a collection of values for one key/**
     * {@inheritDoc}
     * <p>
     * <p>Creates an empty {@code HashSet} for a collection of values for one key.
     *
     * @return a new {@code HashSet} containing a collection of values for one key
     */
    @Override
    Set<V> createCollection() {
        return Sets.newHashSetWithExpectedSize(expectedValuesPerKey);
    }

    
@serialData
expectedValuesPerKey, number of distinct keys, and then for
each distinct key: the key, number of values for that key, and the
key's values/**
     * @serialData expectedValuesPerKey, number of distinct keys, and then for
     * each distinct key: the key, number of values for that key, and the
     * key's values
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
        stream.writeInt(expectedValuesPerKey);
        Serialization.writeMultimap(this, stream);
    }

    private void readObject(ObjectInputStream stream)
            throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        expectedValuesPerKey = stream.readInt();
        int distinctKeys = Serialization.readCount(stream);
        Map<K, Collection<V>> map = Maps.newHashMapWithExpectedSize(distinctKeys);
        setMap(map);
        Serialization.populateMultimap(this, stream, distinctKeys);
    }
}