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* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.
*/
package org.elasticsearch.common.collect;
import com.carrotsearch.hppc.ObjectIntHashMap;
import com.carrotsearch.hppc.ObjectLookupContainer;
import com.carrotsearch.hppc.ObjectObjectHashMap;
import com.carrotsearch.hppc.cursors.ObjectCursor;
import java.util.Iterator;
public final class HppcMaps {
private HppcMaps() {
}
/**
* Returns a new map with the given number of expected elements.
*
* @param expectedElements
* The expected number of elements guaranteed not to cause buffer
* expansion (inclusive).
*/
public static ObjectObjectHashMap newMap(int expectedElements) {
return new ObjectObjectHashMap<>(expectedElements);
}
/**
* Returns a new map with a default initial capacity.
*/
public static ObjectObjectHashMap newMap() {
return newMap(16);
}
/**
* Returns a map like {@link #newMap()} that does not accept null keys
*/
public static ObjectObjectHashMap newNoNullKeysMap() {
return ensureNoNullKeys(16);
}
/**
* Returns a map like {@link #newMap(int)} that does not accept null keys
*
* @param expectedElements
* The expected number of elements guaranteed not to cause buffer
* expansion (inclusive).
*/
public static ObjectObjectHashMap newNoNullKeysMap(int expectedElements) {
return ensureNoNullKeys(expectedElements);
}
/**
* Wraps the given map and prevent adding of null keys.
*
* @param expectedElements
* The expected number of elements guaranteed not to cause buffer
* expansion (inclusive).
*/
public static ObjectObjectHashMap ensureNoNullKeys(int expectedElements) {
return new ObjectObjectHashMap(expectedElements) {
@Override
public V put(K key, V value) {
if (key == null) {
throw new IllegalArgumentException("Map key must not be null");
}
return super.put(key, value);
}
};
}
/**
* @return an intersection view over the two specified containers (which can be KeyContainer or ObjectHashSet).
*/
// Hppc has forEach, but this means we need to build an intermediate set, with this method we just iterate
// over each unique value without creating a third set.
public static Iterable intersection(ObjectLookupContainer container1, final ObjectLookupContainer container2) {
assert container1 != null && container2 != null;
final Iterator> iterator = container1.iterator();
final Iterator intersection = new Iterator() {
T current;
@Override
public boolean hasNext() {
if (iterator.hasNext()) {
do {
T next = iterator.next().value;
if (container2.contains(next)) {
current = next;
return true;
}
} while (iterator.hasNext());
}
return false;
}
@Override
public T next() {
return current;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
return new Iterable() {
@Override
public Iterator iterator() {
return intersection;
}
};
}
public static final class Object {
public static final class Integer {
public static ObjectIntHashMap ensureNoNullKeys(int capacity, float loadFactor) {
return new ObjectIntHashMap(capacity, loadFactor) {
@Override
public int put(V key, int value) {
if (key == null) {
throw new IllegalArgumentException("Map key must not be null");
}
return super.put(key, value);
}
};
}
}
}
}