/*
* LensKit, an open source recommender systems toolkit.
* Copyright 2010-2014 LensKit Contributors. See CONTRIBUTORS.md.
* Work on LensKit has been funded by the National Science Foundation under
* grants IIS 05-34939, 08-08692, 08-12148, and 10-17697.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package org.grouplens.lenskit.data.snapshot;
import org.grouplens.lenskit.data.pref.IndexedPreference;
import org.grouplens.lenskit.data.pref.Preference;
import org.grouplens.lenskit.data.pref.Preferences;
import org.junit.Before;
import org.junit.Test;
import java.util.Random;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.notNullValue;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
/**
* @author <a href="http://www.grouplens.org">GroupLens Research</a>
*/
public class PackedPreferenceDataBuilderTest {
PackedPreferenceDataBuilder bld;
@Before
public void createBuilder() {
bld = new PackedPreferenceDataBuilder();
}
@Test
public void testInitialState() {
assertThat(bld.size(), equalTo(0));
PackedPreferenceData data = bld.build();
assertThat(data, notNullValue());
assertThat(data.size(), equalTo(0));
}
@Test
public void testAddPreference() {
Preference pref = Preferences.make(10, 39, 3.5);
int idx = bld.add(pref);
assertThat(idx, equalTo(0));
assertThat(bld.size(), equalTo(1));
PackedPreferenceData data = bld.build();
assertThat(data.size(), equalTo(1));
IndexedPreference p2 = data.preference(0);
assertThat(p2, equalTo(pref));
assertThat(p2.getIndex(), equalTo(0));
assertThat(p2.getUserIndex(), equalTo(0));
assertThat(p2.getItemIndex(), equalTo(0));
}
@Test
public void testAddMany() {
Random rnd = new Random();
long[] users = new long[500];
long[] items = new long[1000];
for (int i = 0; i < 500; i++) {
users[i] = rnd.nextInt(20000);
items[i * 2] = rnd.nextInt(20000);
items[i * 2 + 1] = rnd.nextInt(20000);
}
Preference[] prefs = new Preference[10000];
for (int i = 0; i < 10000; i++) {
prefs[i] = Preferences.make(
users[rnd.nextInt(500)],
items[rnd.nextInt(1000)],
rnd.nextGaussian());
bld.add(prefs[i]);
}
assertThat(bld.size(), equalTo(10000));
PackedPreferenceData data = bld.build();
assertThat(data.size(), equalTo(10000));
PackedPreferenceData.IndirectPreference ip = data.preference(-1);
for (int i = 0; i < 10000; i++) {
ip.setIndex(i);
assertTrue(ip.isValid());
assertThat(ip, equalTo(prefs[i]));
assertThat(ip.getUserIndex(),
equalTo(data.getUserIndex().getIndex(prefs[i].getUserId())));
assertThat(ip.getItemIndex(),
equalTo(data.getItemIndex().getIndex(prefs[i].getItemId())));
}
}
@Test
public void testRemove() {
bld.add(Preferences.make(1, 3, 20));
bld.add(Preferences.make(4, 2, -3));
bld.add(Preferences.make(2, 3, Math.PI));
assertThat(bld.size(), equalTo(3));
bld.release(1);
assertThat(bld.size(), equalTo(2));
PackedPreferenceData data = bld.build();
assertThat(data.size(), equalTo(2));
assertThat(data.preference(0),
equalTo(Preferences.make(1, 3, 20)));
assertThat(data.preference(1),
equalTo(Preferences.make(2, 3, Math.PI)));
}
@Test
public void testRemoveLast() {
bld.add(Preferences.make(1, 3, 20));
bld.add(Preferences.make(4, 2, -3));
bld.add(Preferences.make(2, 3, Math.PI));
assertThat(bld.size(), equalTo(3));
bld.release(2);
assertThat(bld.size(), equalTo(2));
PackedPreferenceData data = bld.build();
assertThat(data.size(), equalTo(2));
assertThat(data.preference(0),
equalTo(Preferences.make(1, 3, 20)));
assertThat(data.preference(1),
equalTo(Preferences.make(4, 2, -3)));
}
@Test(expected = IndexOutOfBoundsException.class)
public void testRemoveBad() {
bld.add(Preferences.make(1, 3, 20));
bld.add(Preferences.make(4, 2, -3));
bld.add(Preferences.make(2, 3, Math.PI));
bld.release(7);
}
@Test
public void testReuse() {
bld.add(Preferences.make(1, 3, 20));
bld.add(Preferences.make(4, 2, -3));
bld.add(Preferences.make(2, 3, Math.PI));
assertThat(bld.size(), equalTo(3));
bld.release(1);
assertThat(bld.size(), equalTo(2));
int idx = bld.add(Preferences.make(7, 2, Math.E));
assertThat(bld.size(), equalTo(3));
assertThat(idx, equalTo(1));
PackedPreferenceData data = bld.build();
assertThat(data.size(), equalTo(3));
assertThat(data.preference(0),
equalTo(Preferences.make(1, 3, 20)));
assertThat(data.preference(1),
equalTo(Preferences.make(7, 2, Math.E)));
assertThat(data.preference(2),
equalTo(Preferences.make(2, 3, Math.PI)));
}
}