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/*
 * 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 com.facebook.presto.jdbc.internal.guava.collect;

import com.facebook.presto.jdbc.internal.guava.annotations.GwtCompatible;
import com.facebook.presto.jdbc.internal.guava.annotations.GwtIncompatible;
import com.facebook.presto.jdbc.internal.guava.annotations.VisibleForTesting;
import com.facebook.presto.jdbc.internal.guava.base.Preconditions;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Collection;
import java.util.Map;
import java.util.Set;

/**
 * Implementation of {@link 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 {@link Multimaps#synchronizedSetMultimap}. * * @author Jared Levy * @since 2.0 */ @GwtCompatible(serializable = true, emulated = true) public final class HashMultimap extends HashMultimapGwtSerializationDependencies { private static final int DEFAULT_VALUES_PER_KEY = 2; @VisibleForTesting transient int expectedValuesPerKey = DEFAULT_VALUES_PER_KEY; /** * Creates a new, empty {@code HashMultimap} with the default initial capacities. * *

This method will soon be deprecated in favor of {@code * MultimapBuilder.hashKeys().hashSetValues().build()}. */ public static HashMultimap create() { return new HashMultimap<>(); } /** * Constructs an empty {@code HashMultimap} with enough capacity to hold the specified numbers of * keys and values without rehashing. * *

This method will soon be deprecated in favor of {@code * MultimapBuilder.hashKeys(expectedKeys).hashSetValues(expectedValuesPerKey).build()}. * * @param expectedKeys the expected number of distinct keys * @param expectedValuesPerKey the expected average number of values per key * @throws IllegalArgumentException if {@code expectedKeys} or {@code expectedValuesPerKey} is * negative */ public static HashMultimap create(int expectedKeys, int expectedValuesPerKey) { return new HashMultimap<>(expectedKeys, expectedValuesPerKey); } /** * Constructs a {@code HashMultimap} with the same mappings as the specified multimap. If a * key-value mapping appears multiple times in the input multimap, it only appears once in the * constructed multimap. * *

This method will soon be deprecated in favor of {@code * MultimapBuilder.hashKeys().hashSetValues().build(multimap)}. * * @param multimap the multimap whose contents are copied to this multimap */ public static HashMultimap create(Multimap multimap) { return new HashMultimap<>(multimap); } private HashMultimap() { this(12, DEFAULT_VALUES_PER_KEY); } private HashMultimap(int expectedKeys, int expectedValuesPerKey) { super(Platform.>newHashMapWithExpectedSize(expectedKeys)); Preconditions.checkArgument(expectedValuesPerKey >= 0); this.expectedValuesPerKey = expectedValuesPerKey; } private HashMultimap(Multimap multimap) { super(Platform.>newHashMapWithExpectedSize(multimap.keySet().size())); putAll(multimap); } /** * {@inheritDoc} * *

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 createCollection() { return Platform.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 */ @GwtIncompatible // java.io.ObjectOutputStream private void writeObject(ObjectOutputStream stream) throws IOException { stream.defaultWriteObject(); Serialization.writeMultimap(this, stream); } @GwtIncompatible // java.io.ObjectInputStream private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException { stream.defaultReadObject(); expectedValuesPerKey = DEFAULT_VALUES_PER_KEY; int distinctKeys = Serialization.readCount(stream); Map> map = Platform.newHashMapWithExpectedSize(12); setMap(map); Serialization.populateMultimap(this, stream, distinctKeys); } @GwtIncompatible // Not needed in emulated source private static final long serialVersionUID = 0; }





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