EvictingQueueTests.java

/*
 * Copyright (C) 2012 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.elasticsearch.common.collect;

import org.elasticsearch.common.util.CollectionUtils;
import org.elasticsearch.test.ESTestCase;

import java.util.Collections;
import java.util.NoSuchElementException;

public class EvictingQueueTests extends ESTestCase {
    public void testCreateWithNegativeSize() throws Exception {
        try {
            new EvictingQueue<>(-1);
            fail();
        } catch (IllegalArgumentException expected) {
        }
    }

    public void testCreateWithZeroSize() throws Exception {
        EvictingQueue<String> queue = new EvictingQueue<>(0);
        assertEquals(0, queue.size());

        assertTrue(queue.add("hi"));
        assertEquals(0, queue.size());

        assertTrue(queue.offer("hi"));
        assertEquals(0, queue.size());

        assertFalse(queue.remove("hi"));
        assertEquals(0, queue.size());

        try {
            queue.element();
            fail();
        } catch (NoSuchElementException expected) {}

        assertNull(queue.peek());
        assertNull(queue.poll());
        try {
            queue.remove();
            fail();
        } catch (NoSuchElementException expected) {}
    }

    public void testRemainingCapacityMaximumSizeZero() {
        EvictingQueue<String> queue = new EvictingQueue<>(0);
        assertEquals(0, queue.remainingCapacity());
    }

    public void testRemainingCapacityMaximumSizeOne() {
        EvictingQueue<String> queue = new EvictingQueue<>(1);
        assertEquals(1, queue.remainingCapacity());
        queue.add("hi");
        assertEquals(0, queue.remainingCapacity());
    }

    public void testRemainingCapacityMaximumSizeThree() {
        EvictingQueue<String> queue = new EvictingQueue<>(3);
        assertEquals(3, queue.remainingCapacity());
        queue.add("hi");
        assertEquals(2, queue.remainingCapacity());
        queue.add("hi");
        assertEquals(1, queue.remainingCapacity());
        queue.add("hi");
        assertEquals(0, queue.remainingCapacity());
    }

    public void testEvictingAfterOne() throws Exception {
        EvictingQueue<String> queue = new EvictingQueue<>(1);
        assertEquals(0, queue.size());
        assertEquals(1, queue.remainingCapacity());

        assertTrue(queue.add("hi"));
        assertEquals("hi", queue.element());
        assertEquals("hi", queue.peek());
        assertEquals(1, queue.size());
        assertEquals(0, queue.remainingCapacity());

        assertTrue(queue.add("there"));
        assertEquals("there", queue.element());
        assertEquals("there", queue.peek());
        assertEquals(1, queue.size());
        assertEquals(0, queue.remainingCapacity());

        assertEquals("there", queue.remove());
        assertEquals(0, queue.size());
        assertEquals(1, queue.remainingCapacity());
    }

    public void testEvictingAfterThree() throws Exception {
        EvictingQueue<String> queue = new EvictingQueue<>(3);
        assertEquals(0, queue.size());
        assertEquals(3, queue.remainingCapacity());

        assertTrue(queue.add("one"));
        assertTrue(queue.add("two"));
        assertTrue(queue.add("three"));
        assertEquals("one", queue.element());
        assertEquals("one", queue.peek());
        assertEquals(3, queue.size());
        assertEquals(0, queue.remainingCapacity());

        assertTrue(queue.add("four"));
        assertEquals("two", queue.element());
        assertEquals("two", queue.peek());
        assertEquals(3, queue.size());
        assertEquals(0, queue.remainingCapacity());

        assertEquals("two", queue.remove());
        assertEquals(2, queue.size());
        assertEquals(1, queue.remainingCapacity());
    }

    public void testAddAll() throws Exception {
        EvictingQueue<String> queue = new EvictingQueue<>(3);
        assertEquals(0, queue.size());
        assertEquals(3, queue.remainingCapacity());

        assertTrue(queue.addAll(CollectionUtils.arrayAsArrayList("one", "two", "three")));
        assertEquals("one", queue.element());
        assertEquals("one", queue.peek());
        assertEquals(3, queue.size());
        assertEquals(0, queue.remainingCapacity());

        assertTrue(queue.addAll(Collections.singletonList("four")));
        assertEquals("two", queue.element());
        assertEquals("two", queue.peek());
        assertEquals(3, queue.size());
        assertEquals(0, queue.remainingCapacity());

        assertEquals("two", queue.remove());
        assertEquals(2, queue.size());
        assertEquals(1, queue.remainingCapacity());
    }
}