com.twitter.graphjet.bipartite.edgepool.PowerLawDegreeEdgePoolTest.java Source code

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/**
 * Copyright 2016 Twitter. All rights reserved.
 *
 * 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 com.twitter.graphjet.bipartite.edgepool;

import java.util.List;
import java.util.Random;

import com.google.common.collect.Lists;

import org.apache.commons.lang3.tuple.Pair;
import org.junit.Test;

import static org.junit.Assert.assertEquals;

import com.twitter.graphjet.stats.NullStatsReceiver;

import it.unimi.dsi.fastutil.ints.IntArrayList;

import static com.twitter.graphjet.bipartite.edgepool.EdgePoolConcurrentTestHelper.runConcurrentReadWriteThreads;
import static com.twitter.graphjet.bipartite.edgepool.EdgePoolConcurrentTestHelper.testRandomConcurrentReadWriteThreads;

public class PowerLawDegreeEdgePoolTest {
    private static final double EPSILON = 0.00001;

    /**
     * Test helper that adds edges for a specific graph to the given edge pool. Might be reusable
     * across {@link EdgePool}s
     *
     * @param edgePool  to add edges to
     */
    public static void addEdgesToPool(EdgePool edgePool) {
        edgePool.addEdge(1, 11);
        edgePool.addEdge(1, 12);
        edgePool.addEdge(4, 41);
        edgePool.addEdge(2, 21);
        edgePool.addEdge(4, 42);
        edgePool.addEdge(3, 31);
        edgePool.addEdge(2, 22);
        edgePool.addEdge(1, 13);
        edgePool.addEdge(1, 14);
        edgePool.addEdge(4, 43);
        edgePool.addEdge(1, 15);
        edgePool.addEdge(1, 16);
        edgePool.addEdge(5, 51); // violates the maxNumNodes param
        edgePool.addEdge(2, 23); // violates the power law assumption
        edgePool.addEdge(1, 17); // violates the max degree param
    }

    /**
     * Test helper that adds edges for a specific graph to the given edge pool. Might be reusable
     * across {@link EdgePool}s
     *
     * @param edgePool  to add edges to
     */
    public static void testAndResetPool(EdgePool edgePool) {
        assertEquals(7, edgePool.getNodeDegree(1));
        assertEquals(3, edgePool.getNodeDegree(2));
        assertEquals(1, edgePool.getNodeDegree(3));
        assertEquals(3, edgePool.getNodeDegree(4));

        assertEquals(new IntArrayList(new int[] { 11, 12, 13, 14, 15, 16, 17 }),
                new IntArrayList(edgePool.getNodeEdges(1)));
        assertEquals(new IntArrayList(new int[] { 21, 22, 23 }), new IntArrayList(edgePool.getNodeEdges(2)));
        assertEquals(new IntArrayList(new int[] { 31 }), new IntArrayList(edgePool.getNodeEdges(3)));
        assertEquals(new IntArrayList(new int[] { 41, 42, 43 }), new IntArrayList(edgePool.getNodeEdges(4)));
        assertEquals(new IntArrayList(new int[] { 51 }), new IntArrayList(edgePool.getNodeEdges(5)));

        Random random = new Random(90238490238409L);
        int numSamples = 5;

        assertEquals(new IntArrayList(new int[] { 13, 13, 11, 15, 14 }),
                new IntArrayList(edgePool.getRandomNodeEdges(1, numSamples, random)));
        assertEquals(new IntArrayList(new int[] { 22, 22, 21, 23, 22 }),
                new IntArrayList(edgePool.getRandomNodeEdges(2, numSamples, random)));
        assertEquals(new IntArrayList(new int[] { 31, 31, 31, 31, 31 }),
                new IntArrayList(edgePool.getRandomNodeEdges(3, numSamples, random)));
        assertEquals(new IntArrayList(new int[] { 43, 41, 43, 41, 42 }),
                new IntArrayList(edgePool.getRandomNodeEdges(4, numSamples, random)));
        assertEquals(new IntArrayList(new int[] { 51, 51, 51, 51, 51 }),
                new IntArrayList(edgePool.getRandomNodeEdges(5, numSamples, random)));

        assertEquals(0.003814697265625, edgePool.getFillPercentage(), EPSILON);

        RecyclePoolMemory.recyclePowerLawDegreeEdgePool((PowerLawDegreeEdgePool) edgePool);
    }

    @Test
    public void testPowerLawDegreeEdgePool() throws Exception {
        int maxNumNodes = 4;
        int maxDegree = 6;
        PowerLawDegreeEdgePool powerLawDegreeEdgePool = new PowerLawDegreeEdgePool(maxNumNodes, maxDegree, 2.0,
                new NullStatsReceiver());

        for (int i = 0; i < 3; i++) {
            addEdgesToPool(powerLawDegreeEdgePool);
            testAndResetPool(powerLawDegreeEdgePool);
        }
    }

    @Test
    public void testGetPoolForEdgeNumber() throws Exception {
        assertEquals(0, PowerLawDegreeEdgePool.getPoolForEdgeNumber(0));
        assertEquals(0, PowerLawDegreeEdgePool.getPoolForEdgeNumber(1));
        assertEquals(1, PowerLawDegreeEdgePool.getPoolForEdgeNumber(2));
        for (int i = 0; i < 1000; i++) {
            assertEquals((int) Math.floor(Math.log(i + 2) / Math.log(2.0) - 1.0),
                    PowerLawDegreeEdgePool.getPoolForEdgeNumber(i));
        }
    }

    @Test
    public void testGetPoolNumberedEdge() throws Exception {
        int maxNumNodes = 4;
        int maxDegree = 6;
        PowerLawDegreeEdgePool powerLawDegreeEdgePool = new PowerLawDegreeEdgePool(maxNumNodes, maxDegree, 2.0,
                new NullStatsReceiver());
        addEdgesToPool(powerLawDegreeEdgePool);

        assertEquals(11, powerLawDegreeEdgePool.getNumberedEdge(1, 0));
        assertEquals(12, powerLawDegreeEdgePool.getNumberedEdge(1, 1));
        assertEquals(13, powerLawDegreeEdgePool.getNumberedEdge(1, 2));
        assertEquals(14, powerLawDegreeEdgePool.getNumberedEdge(1, 3));
        assertEquals(15, powerLawDegreeEdgePool.getNumberedEdge(1, 4));
        assertEquals(16, powerLawDegreeEdgePool.getNumberedEdge(1, 5));
        assertEquals(21, powerLawDegreeEdgePool.getNumberedEdge(2, 0));
        assertEquals(22, powerLawDegreeEdgePool.getNumberedEdge(2, 1));
        assertEquals(31, powerLawDegreeEdgePool.getNumberedEdge(3, 0));
        assertEquals(41, powerLawDegreeEdgePool.getNumberedEdge(4, 0));
        assertEquals(42, powerLawDegreeEdgePool.getNumberedEdge(4, 1));
        assertEquals(43, powerLawDegreeEdgePool.getNumberedEdge(4, 2));
    }

    @Test
    public void testExtremelySkewedGraph() {
        int maxNumNodes = 4;
        int maxDegree = 6;
        PowerLawDegreeEdgePool powerLawDegreeEdgePool = new PowerLawDegreeEdgePool(maxNumNodes, maxDegree, 2.0,
                new NullStatsReceiver());

        int numEdgesToAdd = 100000;
        // Add a normal node
        powerLawDegreeEdgePool.addEdge(0, 2);
        // Then add a very high degree node
        for (int i = 0; i < numEdgesToAdd; i++) {
            powerLawDegreeEdgePool.addEdge(1, i);
        }
        // Add another node like that
        for (int i = 0; i < numEdgesToAdd; i++) {
            powerLawDegreeEdgePool.addEdge(2, i);
        }

        assertEquals(1, powerLawDegreeEdgePool.getNodeDegree(0));
        assertEquals(numEdgesToAdd, powerLawDegreeEdgePool.getNodeDegree(1));
        assertEquals(numEdgesToAdd, powerLawDegreeEdgePool.getNodeDegree(2));
    }

    @Test
    public void testConcurrentReadWrites() {
        int maxNumNodes = 4;
        int maxDegree = 6;
        PowerLawDegreeEdgePool powerLawDegreeEdgePool = new PowerLawDegreeEdgePool(maxNumNodes, maxDegree, 2.0,
                new NullStatsReceiver());

        @SuppressWarnings("unchecked")
        List<Pair<Integer, Integer>> edgesToAdd = Lists.newArrayList(Pair.of(1, 11), Pair.of(1, 12), Pair.of(4, 41),
                Pair.of(2, 21), Pair.of(4, 42), Pair.of(3, 31), Pair.of(2, 22), Pair.of(1, 13), Pair.of(1, 14),
                Pair.of(4, 43), Pair.of(1, 15), Pair.of(1, 16), Pair.of(5, 51), // violates the maxNumNodes param
                Pair.of(2, 23), // violates the power law assumption
                Pair.of(1, 17) // violates the max degree param
        );

        // Sets up a concurrent read-write situation with the given pool and edges
        List<EdgePoolConcurrentTestHelper.EdgePoolReader> readers = runConcurrentReadWriteThreads(
                powerLawDegreeEdgePool, edgesToAdd);

        // First check that the graph populated correctly
        testAndResetPool(powerLawDegreeEdgePool);

        // Now test all the readers
        assertEquals(1, readers.get(0).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 11 }), readers.get(0).getQueryNodeEdges());
        assertEquals(2, readers.get(1).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 11, 12 }), readers.get(1).getQueryNodeEdges());
        assertEquals(1, readers.get(2).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 41 }), readers.get(2).getQueryNodeEdges());
        assertEquals(1, readers.get(3).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 21 }), readers.get(3).getQueryNodeEdges());
        assertEquals(2, readers.get(4).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 41, 42 }), readers.get(4).getQueryNodeEdges());
        assertEquals(1, readers.get(5).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 31 }), readers.get(5).getQueryNodeEdges());
        assertEquals(2, readers.get(6).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 21, 22 }), readers.get(6).getQueryNodeEdges());
        assertEquals(3, readers.get(7).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 11, 12, 13 }), readers.get(7).getQueryNodeEdges());
        assertEquals(4, readers.get(8).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 11, 12, 13, 14 }), readers.get(8).getQueryNodeEdges());
        assertEquals(3, readers.get(9).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 41, 42, 43 }), readers.get(9).getQueryNodeEdges());
        assertEquals(5, readers.get(10).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 11, 12, 13, 14, 15 }), readers.get(10).getQueryNodeEdges());
        assertEquals(6, readers.get(11).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 11, 12, 13, 14, 15, 16 }), readers.get(11).getQueryNodeEdges());
        assertEquals(1, readers.get(12).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 51 }), readers.get(12).getQueryNodeEdges());
        assertEquals(3, readers.get(13).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 21, 22, 23 }), readers.get(13).getQueryNodeEdges());
        assertEquals(7, readers.get(14).getQueryNodeDegree());
        assertEquals(new IntArrayList(new int[] { 11, 12, 13, 14, 15, 16, 17 }),
                readers.get(14).getQueryNodeEdges());
    }

    @Test
    public void testRandomConcurrentReadWrites() {
        int maxNumNodes = 10;
        int maxDegree = 10;
        PowerLawDegreeEdgePool powerLawDegreeEdgePool = new PowerLawDegreeEdgePool(maxNumNodes, maxDegree, 2.0,
                new NullStatsReceiver());

        // Sets up a concurrent read-write situation with the given pool and edges
        Random random = new Random(89234758923475L);
        testRandomConcurrentReadWriteThreads(powerLawDegreeEdgePool, 5, 10 * maxNumNodes, maxDegree, 0.1, random);
    }
}