EvictingQueueTest.java

/*
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 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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package org.jmxtrans.agent.util.collect;

import org.junit.Test;

import java.util.Arrays;

import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;

/**
 *
 */
public class EvictingQueueTest {

    @Test(expected = IllegalArgumentException.class)
    public void creating_negative_evictingQueue_fails() throws Exception {
        EvictingQueue.create(-1);
    }

    @Test(expected = IllegalArgumentException.class)
    public void creating_zeroSize_evictingQueue_fails() throws Exception {
        EvictingQueue.create(0);
    }

    @Test
    public void testEvictingAfterOne() throws Exception {
        EvictingQueue<String> queue = EvictingQueue.create(1);

        assertThat(queue.size(), is(0));

        {
            boolean added = queue.add("one");
            assertThat(added, is(true));
            assertThat(queue.size(), is(1));
            assertThat(queue.peek(), is("one"));
        }
        {
            boolean added = queue.add("two");
            assertThat(added, is(true));
            assertThat(queue.size(), is(1));
            assertThat(queue.peek(), is("two"));
            String polled = queue.poll();
            assertThat(polled, is("two"));
            assertThat(queue.size(), is(0));
        }
    }

    @Test
    public void testEvictingAfterThree() throws Exception {
        EvictingQueue<String> queue = EvictingQueue.create(3);
        assertThat(queue.size(), is(0));

        {
            boolean added = queue.addAll(Arrays.asList("one", "two", "three"));
            assertThat(added, is(true));
            assertThat(queue.element(), is("one"));
            assertThat(queue.peek(), is("one"));
            assertThat(queue.size(), is(3));
        }
        {
            boolean added = queue.addAll(Arrays.asList("four", "five"));
            assertThat(added, is(true));
            assertThat(queue.peek(), is("three"));
            assertThat(queue.size(), is(3));
        }
        {
            String polled = queue.poll();
            assertThat(polled, is("three"));
            assertThat(queue.size(), is(2));
        }
    }

    public void method_addAll_behaves_as_multi_add() throws Exception {
        EvictingQueue<String> queue = EvictingQueue.create(3);
        assertThat(queue.size(), is(0));

        {
            boolean added = queue.addAll(Arrays.asList("one", "two", "three"));
            assertThat(added, is(true));
            assertThat(queue.element(), is("one"));
            assertThat(queue.peek(), is("one"));
            assertThat(queue.size(), is(3));
        }
        {
            boolean added = queue.addAll(Arrays.asList("four", "five"));
            assertThat(added, is(true));
            assertThat(queue.peek(), is("three"));
            assertThat(queue.size(), is(3));
        }
        {
            String polled = queue.poll();
            assertThat(polled, is("three"));
            assertThat(queue.size(), is(2));
        }
    }
}