/*
* Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
* license agreements. See the NOTICE file distributed with this work for
* additional information regarding copyright ownership. Crate 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.
*
* However, if you have executed another commercial license agreement
* with Crate these terms will supersede the license and you may use the
* software solely pursuant to the terms of the relevant commercial agreement.
*/
package io.crate.core.collections;
import java.util.NoSuchElementException;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class BlockingEvictingQueue<E> extends ArrayBlockingQueue<E> implements BlockingQueue<E> {
public BlockingEvictingQueue(int capacity) {
super(capacity);
assert capacity > 0 : "capacity should be > 0";
}
@Override
public boolean offer(E e) {
while (true) {
if (!super.offer(e)) {
try {
super.remove();
} catch (NoSuchElementException ex) {
// race condition, queue was already empty
}
} else {
break;
}
}
return true;
}
}