| /** |
| * 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 java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mapred.Counters; |
| import org.apache.hadoop.mapred.Reducer; |
| import org.apache.hadoop.mrunit.mock.MockOutputCollector; |
| import org.apache.hadoop.mrunit.mock.MockReporter; |
| import org.apache.hadoop.mrunit.types.Pair; |
| |
| /** |
| * 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 class ReduceDriver<K1, V1, K2, V2> extends ReduceDriverBase<K1, V1, K2, V2> { |
| |
| public static final Log LOG = LogFactory.getLog(ReduceDriver.class); |
| |
| private Reducer<K1, V1, K2, V2> myReducer; |
| private Counters counters; |
| |
| public ReduceDriver(final Reducer<K1, V1, K2, V2> r) { |
| myReducer = r; |
| counters = new Counters(); |
| } |
| |
| public ReduceDriver() { |
| counters = new Counters(); |
| } |
| |
| /** @return the counters used in this test */ |
| public Counters getCounters() { |
| return counters; |
| } |
| |
| /** Sets the counters object to use for this test. |
| * @param ctrs The counters object to use. |
| */ |
| public void setCounters(final Counters ctrs) { |
| this.counters = ctrs; |
| } |
| |
| /** Sets the counters to use and returns self for fluent style */ |
| public ReduceDriver<K1, V1, K2, V2> withCounters(final Counters ctrs) { |
| setCounters(ctrs); |
| return this; |
| } |
| |
| |
| /** |
| * Sets the reducer object to use for this test |
| * |
| * @param r |
| * The reducer object to use |
| */ |
| public void setReducer(Reducer<K1, V1, K2, V2> r) { |
| myReducer = r; |
| } |
| |
| /** |
| * Identical to setReducer(), but with fluent programming style |
| * |
| * @param r |
| * The Reducer to use |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withReducer(Reducer<K1, V1, K2, V2> r) { |
| setReducer(r); |
| return this; |
| } |
| |
| public Reducer<K1, V1, K2, V2> getReducer() { |
| return myReducer; |
| } |
| |
| /** |
| * Identical to setInputKey() but with fluent programming style |
| * |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withInputKey(K1 key) { |
| setInputKey(key); |
| return this; |
| } |
| |
| /** |
| * Identical to addInputValue() but with fluent programming style |
| * |
| * @param val |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withInputValue(V1 val) { |
| addInputValue(val); |
| return this; |
| } |
| |
| /** |
| * Identical to addInputValues() but with fluent programming style |
| * |
| * @param values |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withInputValues(List<V1> values) { |
| addInputValues(values); |
| return this; |
| } |
| |
| /** |
| * Identical to setInput() but returns self for fluent programming style |
| * |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withInput(K1 key, List<V1> values) { |
| setInput(key, values); |
| return this; |
| } |
| |
| /** |
| * Works like addOutput(), but returns self for fluent style |
| * |
| * @param outputRecord |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withOutput(Pair<K2, V2> outputRecord) { |
| addOutput(outputRecord); |
| return this; |
| } |
| |
| /** |
| * Works like addOutput(), but returns self for fluent style |
| * |
| * @param key The key part of a (k, v) pair to add |
| * @param val The val part of a (k, v) pair to add |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withOutput(K2 key, V2 val) { |
| addOutput(key, val); |
| return this; |
| } |
| |
| /** |
| * Identical to setInput, but with a fluent programming style |
| * |
| * @param input |
| * A string of the form "key \t val". Trims any whitespace. |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withInputFromString(String input) { |
| setInputFromString(input); |
| return this; |
| } |
| |
| /** |
| * Identical to addOutput, but with a fluent programming style |
| * |
| * @param output |
| * A string of the form "key \t val". Trims any whitespace. |
| * @return this |
| */ |
| public ReduceDriver<K1, V1, K2, V2> withOutputFromString(String output) { |
| addOutputFromString(output); |
| return this; |
| } |
| |
| @Override |
| public List<Pair<K2, V2>> run() throws IOException { |
| MockOutputCollector<K2, V2> outputCollector = |
| new MockOutputCollector<K2, V2>(); |
| MockReporter reporter = new MockReporter(MockReporter.ReporterType.Reducer, getCounters()); |
| |
| myReducer.reduce(inputKey, inputValues.iterator(), outputCollector, |
| reporter); |
| |
| List<Pair<K2, V2>> outputs = outputCollector.getOutputs(); |
| return outputs; |
| } |
| |
| @Override |
| public String toString() { |
| return "ReduceDriver (" + myReducer + ")"; |
| } |
| } |
| |