com.bah.culvert.test.Utils.java Source code

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Here is the source code for com.bah.culvert.test.Utils.java

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/**
 * Copyright 2011 Booz Allen Hamilton.
 * 
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership. Booz Allen Hamilton
 * 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 com.bah.culvert.test;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;

import com.bah.culvert.data.CKeyValue;
import com.bah.culvert.data.Result;

/**
 * Culvert testing utilities
 */
public final class Utils {

    private Utils() {
    }

    /**
     * Test an iterator to make sure it has the correct results
     * @param iter Iterable to check
     * @param expectedRows number of results
     * @param expectedValues all the key/values over all the Results, in order
     */
    public static void testResultIterator(Iterator<Result> iter, int expectedRows, List<CKeyValue> expectedValues) {

        if (expectedRows > 0)
            assertTrue(iter.hasNext());
        int results = 0;
        int values = 0;

        while (iter.hasNext()) {
            Result r = iter.next();
            for (CKeyValue kv : r.getKeyValues()) {
                assertEquals(expectedValues.get(values), kv);
                values++;
            }

            if (!r.getKeyValues().isEmpty())
                results++;
        }
        assertEquals("Number of rows differed from expected number of rows", expectedRows, results);
        assertEquals("Number of values differed from expected number of values", expectedValues.size(), values);
    }

    /**
     * Test that the specified iterator has the expected number of results and
     * values
     * @param iter
     * @param expectedRows expected total number of results
     * @param expectedValues expected TOTAL number of rows for ALL results
     */
    public static void testResultIterator(Iterator<Result> iter, int expectedRows, int expectedValues) {
        testResultIterator(iter, expectedRows, expectedValues, false);
    }

    /**
     * Test that the specified iterator has the expected number of results and
     * values
     * @param iter
     * @param expectedRows expected total number of results
     * @param expectedValues expected TOTAL number of rows for ALL results
     * @param print <tt>true</tt> to print out all the received rows. Useful for
     *        debugging
     */
    public static void testResultIterator(Iterator<Result> iter, int expectedRows, int expectedValues,
            boolean print) {

        if (expectedRows > 0)
            assertTrue(iter.hasNext());

        int results = 0;
        int values = 0;
        while (iter.hasNext()) {
            Result r = iter.next();
            if (!r.getKeyValues().isEmpty())
                results++;

            for (CKeyValue kv : r.getKeyValues()) {
                if (print)
                    System.out.println(kv);

                values++;
            }
        }

        assertEquals("Number of rows differed from expected number of rows", expectedRows, results);
        assertEquals("Number of values differed from expected number of values", expectedValues, values);
    }

    /**
     * Checks if the writable will successfully read and write using
     * {@link Writable}'s methods.
     * @param writeable
     * @return The instance read in using
     *         {@link Writable#readFields(java.io.DataInput)}. Can be used for
     *         checking equality.
     * @throws InstantiationException
     * @throws IllegalAccessException
     * @throws IOException
     */
    public static Writable testReadWrite(Writable writeable)
            throws InstantiationException, IllegalAccessException, IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(baos);
        writeable.write(dos);
        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
        DataInputStream dis = new DataInputStream(bais);
        Writable inst = writeable.getClass().newInstance();
        inst.readFields(dis);
        return inst;
    }

    /**
     * Test that the writable both serializes successfully and that the read
     * version will compare equivalently to the original.
     * <p>
     * NOTE: requires that the sent object is comparable to itself
     * @param <T> Class of the writable
     * @param writable to test
     * @return the read in version of the original value
     * @throws IOException
     * @throws IllegalAccessException
     * @throws InstantiationException
     */
    @SuppressWarnings("unchecked")
    public static <T> WritableComparable<T> testReadWrite(WritableComparable<T> writable)
            throws InstantiationException, IllegalAccessException, IOException {
        WritableComparable<T> inst = (WritableComparable<T>) testReadWrite((Writable) writable);
        assertEquals(0, writable.compareTo((T) inst));
        return inst;
    }
}