org.apache.mahout.clustering.spectral.TestVectorCache.java Source code

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/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.mahout.clustering.spectral;

import java.net.URI;

import com.google.common.io.Closeables;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Writable;
import org.apache.mahout.common.HadoopUtil;
import org.apache.mahout.common.MahoutTestCase;
import org.apache.mahout.common.iterator.sequencefile.SequenceFileValueIterator;
import org.apache.mahout.math.DenseVector;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;
import org.junit.Test;

public class TestVectorCache extends MahoutTestCase {

    private static final double[] VECTOR = { 1, 2, 3, 4 };

    @Test
    public void testSave() throws Exception {
        Configuration conf = getConfiguration();
        Writable key = new IntWritable(0);
        Vector value = new DenseVector(VECTOR);
        Path path = getTestTempDirPath("output");

        // write the vector out
        VectorCache.save(key, value, path, conf, true, true);

        // can we read it from here?
        SequenceFileValueIterator<VectorWritable> iterator = new SequenceFileValueIterator<VectorWritable>(path,
                true, conf);
        try {
            VectorWritable old = iterator.next();
            // test if the values are identical
            assertEquals("Saved vector is identical to original", old.get(), value);
        } finally {
            Closeables.close(iterator, true);
        }
    }

    @Test
    public void testLoad() throws Exception {
        // save a vector manually
        Configuration conf = getConfiguration();
        Writable key = new IntWritable(0);
        Vector value = new DenseVector(VECTOR);
        Path path = getTestTempDirPath("output");

        FileSystem fs = FileSystem.get(path.toUri(), conf);
        // write the vector
        path = fs.makeQualified(path);
        fs.deleteOnExit(path);
        HadoopUtil.delete(conf, path);
        SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf, path, IntWritable.class,
                VectorWritable.class);
        try {
            writer.append(key, new VectorWritable(value));
        } finally {
            Closeables.close(writer, false);
        }
        DistributedCache.setCacheFiles(new URI[] { path.toUri() }, conf);

        // load it
        Vector result = VectorCache.load(conf);

        // are they the same?
        assertNotNull("Vector is null", result);
        assertEquals("Loaded vector is not identical to original", result, value);
    }

    @Test
    public void testAll() throws Exception {
        Configuration conf = getConfiguration();
        Vector v = new DenseVector(VECTOR);
        Path toSave = getTestTempDirPath("output");
        Writable key = new IntWritable(0);

        // save it
        VectorCache.save(key, v, toSave, conf);

        // now, load it back
        Vector v2 = VectorCache.load(conf);

        // are they the same?
        assertNotNull("Vector is null", v2);
        assertEquals("Vectors are not identical", v2, v);
    }
}