/*
 * 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;
    }
}

/*
 * 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.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 (!super.offer(e)) {
            poll();
        }
        return true;
    }
}

Simplify BlockingEvictingQueue