/**
* 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.internal.util.ArgumentChecker.returnNonNull;
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.fs.Path;
import org.apache.hadoop.mapred.Counters;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mrunit.internal.counters.CounterWrapper;
import org.apache.hadoop.mrunit.types.Pair;
/**
* Harness that allows you to test a dataflow through a set of Mappers and
* Reducers. You provide a set of (Mapper, Reducer) "jobs" that make up a
* workflow, as well as a set of (key, value) pairs to pass in to the first
* Mapper. You can also specify the outputs you expect to be sent to the final
* Reducer in the pipeline.
*
* By calling runTest(), the harness will deliver the input to the first Mapper,
* feed the intermediate results to the first Reducer (without checking them),
* and proceed to forward this data along to subsequent Mapper/Reducer jobs in
* the pipeline until the final Reducer. The last Reducer's outputs are checked
* against the expected results.
*
* This is designed for slightly more complicated integration tests than the
* MapReduceDriver, which is for smaller unit tests.
*
* (K1, V1) in the type signature refer to the types associated with the inputs
* to the first Mapper. (K2, V2) refer to the types associated with the final
* Reducer's output. No intermediate types are specified.
*/
@SuppressWarnings("rawtypes")
public class PipelineMapReduceDriver<K1, V1, K2, V2> extends
TestDriver<K1, V1, K2, V2, PipelineMapReduceDriver<K1, V1, K2, V2>> {
public static final Log LOG = LogFactory
.getLog(PipelineMapReduceDriver.class);
private List<Pair<Mapper, Reducer>> mapReducePipeline;
private final List<Pair<K1, V1>> inputList;
private Counters counters;
protected Path mapInputPath = new Path("somefile");
public PipelineMapReduceDriver(final List<Pair<Mapper, Reducer>> pipeline) {
this();
mapReducePipeline = returnNonNull(pipeline);
}
public PipelineMapReduceDriver() {
mapReducePipeline = new ArrayList<Pair<Mapper, Reducer>>();
inputList = new ArrayList<Pair<K1, V1>>();
setCounters(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) {
counters = ctrs;
counterWrapper = new CounterWrapper(ctrs);
}
/** Sets the counters to use and returns self for fluent style */
public PipelineMapReduceDriver<K1, V1, K2, V2> withCounters(
final Counters ctrs) {
setCounters(ctrs);
return this;
}
/**
* Add a Mapper and Reducer instance to the pipeline to use with this test
* driver
*
* @param m
* The Mapper instance to add to the pipeline
* @param r
* The Reducer instance to add to the pipeline
*/
public void addMapReduce(final Mapper m, final Reducer r) {
mapReducePipeline.add(new Pair<Mapper, Reducer>(m, r));
}
/**
* Add a Mapper and Reducer instance to the pipeline to use with this test
* driver
*
* @param p
* The Mapper and Reducer instances to add to the pipeline
*/
public void addMapReduce(final Pair<Mapper, Reducer> p) {
mapReducePipeline.add(returnNonNull(p));
}
/**
* Add a Mapper and Reducer instance to the pipeline to use with this test
* driver using fluent style
*
* @param m
* The Mapper instance to use
* @param r
* The Reducer instance to use
*/
public PipelineMapReduceDriver<K1, V1, K2, V2> withMapReduce(final Mapper m,
final Reducer r) {
addMapReduce(m, r);
return this;
}
/**
* Add a Mapper and Reducer instance to the pipeline to use with this test
* driver using fluent style
*
* @param p
* The Mapper and Reducer instances to add to the pipeline
*/
public PipelineMapReduceDriver<K1, V1, K2, V2> withMapReduce(
final Pair<Mapper, Reducer> p) {
addMapReduce(p);
return this;
}
/**
* @return A copy of the list of Mapper and Reducer objects under test
*/
public List<Pair<Mapper, Reducer>> getMapReducePipeline() {
return new ArrayList<Pair<Mapper, Reducer>>(mapReducePipeline);
}
/**
* Adds an input to send to the mapper
*
* @param key
* @param val
*/
public void addInput(final K1 key, final V1 val) {
inputList.add(copyPair(key, val));
}
/**
* Adds list of inputs to send to the mapper
*
* @param inputs
* list of (K, V) pairs
*/
public void addAll(final List<Pair<K1, V1>> inputs) {
for (Pair<K1, V1> input : inputs) {
addInput(input);
}
}
/**
* Identical to addInput() but returns self for fluent programming style
*
* @param key
* @param val
* @return this
*/
public PipelineMapReduceDriver<K1, V1, K2, V2> withInput(final K1 key,
final V1 val) {
addInput(key, val);
return this;
}
/**
* Adds an input to send to the Mapper
*
* @param input
* The (k, v) pair to add to the input list.
*/
public void addInput(final Pair<K1, V1> input) {
addInput(input.getFirst(), input.getSecond());
}
/**
* Identical to addInput() but returns self for fluent programming style
*
* @param input
* The (k, v) pair to add
* @return this
*/
public PipelineMapReduceDriver<K1, V1, K2, V2> withInput(
final Pair<K1, V1> input) {
addInput(input);
return this;
}
/**
* Expects an input of the form "key \t val" Forces the Mapper input types to
* Text.
*
* @param input
* A string of the form "key \t val". Trims any whitespace.
* @deprecated No replacement due to lack of type safety and incompatibility
* with non Text Writables
*/
@Deprecated
@SuppressWarnings("unchecked")
public void addInputFromString(final String input) {
addInput((Pair<K1, V1>) parseTabbedPair(input));
}
/**
* Identical to addInputFromString, but with a fluent programming style
*
* @param input
* A string of the form "key \t val". Trims any whitespace.
* @return this
* @deprecated No replacement due to lack of type safety and incompatibility
* with non Text Writables
*/
@Deprecated
public PipelineMapReduceDriver<K1, V1, K2, V2> withInputFromString(
final String input) {
addInputFromString(input);
return this;
}
/**
* Identical to addAll() but returns self for fluent programming style
*
* @param inputRecords input key/value pairs
* @return this
*/
public PipelineMapReduceDriver<K1, V1, K2, V2> withAll(
final List<Pair<K1, V1>> inputRecords) {
addAll(inputRecords);
return this;
}
/**
* @return the path passed to the mapper InputSplit
*/
public Path getMapInputPath() {
return mapInputPath;
}
/**
* @param mapInputPath Path which is to be passed to the mappers InputSplit
*/
public void setMapInputPath(Path mapInputPath) {
this.mapInputPath = mapInputPath;
}
/**
* @param mapInputPath
* The Path object which will be given to the mapper
* @return
*/
public final PipelineMapReduceDriver<K1, V1, K2, V2> withMapInputPath(Path mapInputPath) {
setMapInputPath(mapInputPath);
return this;
}
@Override
@SuppressWarnings("unchecked")
public List<Pair<K2, V2>> run() throws IOException {
// inputs starts with the user-provided inputs.
List<Pair<K1, V1>> inputs = inputList;
if (inputs.isEmpty()) {
throw new IllegalStateException("No input was provided");
}
if (mapReducePipeline.isEmpty()) {
throw new IllegalStateException("No Mappers or Reducers in pipeline");
}
for (final Pair<Mapper, Reducer> job : mapReducePipeline) {
// Create a MapReduceDriver to run this phase of the pipeline.
final MapReduceDriver mrDriver = MapReduceDriver.newMapReduceDriver(
job.getFirst(), job.getSecond());
mrDriver.setCounters(getCounters());
mrDriver.setConfiguration(getConfiguration());
mrDriver.setMapInputPath(mapInputPath);
// Add the inputs from the user, or from the previous stage of the
// pipeline.
for (final Pair<K1, V1> input : inputs) {
mrDriver.addInput(input);
}
// Run the MapReduce "job". The output of this job becomes
// the input to the next job.
inputs = mrDriver.run();
}
// The last list of values stored in "inputs" is actually the outputs.
// Unfortunately, due to the variable-length list of MR passes the user
// can test, this is not type-safe.
return (List) inputs;
}
/**
* Returns a new PipelineMapReduceDriver without having to specify the generic
* types on the right hand side of the object create statement.
*
* @return new PipelineMapReduceDriver
*/
public static <K1, V1, K2, V2> PipelineMapReduceDriver<K1, V1, K2, V2> newPipelineMapReduceDriver() {
return new PipelineMapReduceDriver<K1, V1, K2, V2>();
}
/**
* Returns a new PipelineMapReduceDriver without having to specify the generic
* types on the right hand side of the object create statement.
*
* @param pipeline
* passed to PipelineMapReduceDriver constructor
* @return new PipelineMapReduceDriver
*/
public static <K1, V1, K2, V2> PipelineMapReduceDriver<K1, V1, K2, V2> newPipelineMapReduceDriver(
final List<Pair<Mapper, Reducer>> pipeline) {
return new PipelineMapReduceDriver<K1, V1, K2, V2>(pipeline);
}
}