src/test/java/com/googlecode/aviator/utils/SyncLRUMapUnitTest.java

package com.googlecode.aviator.utils;

import java.util.concurrent.CyclicBarrier;

import org.junit.Before;
import org.junit.Test;

import static org.junit.Assert.*;


public class SyncLRUMapUnitTest {

    private SyncLRUMap<Integer, Integer> map;


    @Before
    public void setUp() {
        this.map = new SyncLRUMap<Integer, Integer>(10);
    }


    @Test
    public void testPutGet() {
        assertTrue(map.isEmpty());
        assertEquals(0, map.size());
        for (int i = 0; i < 5; i++) {
            assertNull(this.map.get(i));
            this.map.put(i, i);
            assertEquals(i, this.map.get(i));
        }
        assertEquals(5, map.size());
    }


    @Test
    public void testLRU() {
        for (int i = 0; i < 20; i++) {
            assertNull(this.map.get(i));
            this.map.put(i, i);
            assertEquals(i, this.map.get(i));
        }
        assertEquals(10, map.size());
        for (int i = 0; i < 10; i++)
            assertNull(this.map.get(0));
        for (int i = 10; i < 11; i++)
            assertEquals(i, this.map.get(i));
        assertEquals(10, map.size());

    }


    @Test
    public void concurrentTest() throws Exception {
        int threads = 100;
        final CyclicBarrier barrier = new CyclicBarrier(threads + 1);
        for (int i = 0; i < threads; i++) {
            new Thread() {
                public void run() {
                    try {
                        barrier.await();
                        for (int i = 0; i < 10000; i++)
                            map.put(i, i);
                        for (int i = 0; i < 10000; i++)
                            map.get(i);
                        barrier.await();
                    }
                    catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }.start();
        }
        barrier.await();
        barrier.await();
        assertEquals(10, map.size());
        System.out.println(map);
    }
}