| /** |
| * 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.hadoop.mrunit; |
| |
| import static org.apache.hadoop.mrunit.Serialization.copy; |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mrunit.types.Pair; |
| import org.apache.hadoop.util.ReflectionUtils; |
| |
| /** |
| * Harness that allows you to test a Reducer instance. You provide a key and a |
| * set of intermediate values for that key that represent inputs that should be |
| * sent to the Reducer (as if they came from a Mapper), and outputs you expect |
| * to be sent by the Reducer to the collector. By calling runTest(), the harness |
| * will deliver the input to the Reducer and will check its outputs against the |
| * expected results. This is designed to handle a single (k, v*) -> (k, v)* case |
| * from the Reducer, representing a single unit test. Multiple input (k, v*) |
| * sets should go in separate unit tests. |
| */ |
| public abstract class ReduceDriverBase<K1, V1, K2, V2> extends |
| TestDriver<K1, V1, K2, V2> { |
| |
| protected K1 inputKey; |
| private List<V1> inputValues; |
| |
| public ReduceDriverBase() { |
| inputValues = new ArrayList<V1>(); |
| } |
| |
| /** |
| * Returns a list which when iterated over, returns |
| * the same instance of the value each time with different |
| * contents similar to how Hadoop currently works with |
| * Writables. |
| * |
| * @return List of values |
| */ |
| public List<V1> getInputValues() { |
| return new ValueClassInstanceReuseList<V1>(inputValues); |
| } |
| /** |
| * Sets the input key to send to the Reducer |
| * |
| */ |
| public void setInputKey(K1 key) { |
| inputKey = key; |
| } |
| |
| /** |
| * adds an input value to send to the reducer |
| * |
| * @param val |
| */ |
| public void addInputValue(V1 val) { |
| inputValues.add(val); |
| } |
| |
| /** |
| * Sets the input values to send to the reducer; overwrites existing ones |
| * |
| * @param values |
| */ |
| public void setInputValues(List<V1> values) { |
| inputValues.clear(); |
| inputValues.addAll(values); |
| } |
| |
| /** |
| * Adds a set of input values to send to the reducer |
| * |
| * @param values |
| */ |
| public void addInputValues(List<V1> values) { |
| inputValues.addAll(values); |
| } |
| |
| /** |
| * Sets the input to send to the reducer |
| * |
| * @param values |
| */ |
| public void setInput(K1 key, List<V1> values) { |
| setInputKey(key); |
| setInputValues(values); |
| } |
| |
| /** |
| * Adds an output (k, v) pair we expect from the Reducer |
| * |
| * @param outputRecord |
| * The (k, v) pair to add |
| */ |
| public void addOutput(Pair<K2, V2> outputRecord) { |
| if (null != outputRecord) { |
| expectedOutputs.add(outputRecord); |
| } else { |
| throw new IllegalArgumentException("Tried to add null outputRecord"); |
| } |
| } |
| |
| /** |
| * Adds an output (k, v) pair we expect from the Reducer |
| * |
| * @param key |
| * The key part of a (k, v) pair to add |
| * @param val |
| * The val part of a (k, v) pair to add |
| */ |
| public void addOutput(K2 key, V2 val) { |
| addOutput(new Pair<K2, V2>(key, val)); |
| } |
| |
| /** |
| * Expects an input of the form "key \t val, val, val..." Forces the Reducer |
| * input types to Text. |
| * |
| * @param input |
| * A string of the form "key \t val,val,val". Trims any whitespace. |
| */ |
| @SuppressWarnings("unchecked") |
| public void setInputFromString(String input) { |
| if (null == input) { |
| throw new IllegalArgumentException("null input"); |
| } else { |
| Pair<Text, Text> inputPair = parseTabbedPair(input); |
| if (null != inputPair) { |
| // I know this is not type-safe, but I don't know a better way to do |
| // this. |
| setInputKey((K1) inputPair.getFirst()); |
| setInputValues((List<V1>) parseCommaDelimitedList(inputPair.getSecond() |
| .toString())); |
| } else { |
| throw new IllegalArgumentException("Could not parse input pair"); |
| } |
| } |
| } |
| |
| /** |
| * Expects an input of the form "key \t val" Forces the Reducer output types |
| * to Text. |
| * |
| * @param output |
| * A string of the form "key \t val". Trims any whitespace. |
| */ |
| @SuppressWarnings("unchecked") |
| public void addOutputFromString(String output) { |
| if (null == output) { |
| throw new IllegalArgumentException("null input"); |
| } else { |
| Pair<Text, Text> outputPair = parseTabbedPair(output); |
| if (null != outputPair) { |
| // I know this is not type-safe, but I don't know a better way to do |
| // this. |
| addOutput((Pair<K2, V2>) outputPair); |
| } else { |
| throw new IllegalArgumentException("Could not parse output pair"); |
| } |
| } |
| } |
| |
| public abstract List<Pair<K2, V2>> run() throws IOException; |
| |
| @Override |
| public void runTest() throws RuntimeException { |
| |
| String inputKeyStr = "(null)"; |
| |
| if (null != inputKey) { |
| inputKeyStr = inputKey.toString(); |
| } |
| |
| StringBuilder sb = new StringBuilder(); |
| formatValueList(inputValues, sb); |
| |
| LOG.debug("Reducing input (" + inputKeyStr + ", " + sb.toString() + ")"); |
| |
| List<Pair<K2, V2>> outputs = null; |
| try { |
| outputs = run(); |
| validate(outputs); |
| } catch (IOException ioe) { |
| LOG.error("IOException in reducer", ioe); |
| throw new RuntimeException("IOException in reducer: ", ioe); |
| } |
| } |
| |
| protected static class ValueClassInstanceReuseList<T> extends ArrayList<T> { |
| private static final long serialVersionUID = 1L; |
| private T value; |
| private final Configuration conf = new Configuration(); |
| @SuppressWarnings("unchecked") |
| public ValueClassInstanceReuseList(List<T> list) { |
| super(list); |
| if (!list.isEmpty()) { |
| T first = list.get(0); |
| Class<T> klass = (Class<T>) first.getClass(); |
| this.value = ReflectionUtils.newInstance(klass, conf); |
| } |
| } |
| |
| @Override |
| public Iterator<T> iterator() { |
| final Iterator<T> listIterator = super.iterator(); |
| final T currentValue = value; |
| return new Iterator<T>() { |
| private T value = currentValue; |
| private Iterator<T> iterator = listIterator; |
| @Override |
| public boolean hasNext() { |
| return iterator.hasNext(); |
| } |
| |
| @Override |
| public T next() { |
| T next = iterator.next(); |
| copy(next, value, conf); |
| return value; |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException(); |
| } |
| }; |
| } |
| } |
| } |