/*
* Copyright 2013 Cloudera Inc.
*
* Licensed 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.kitesdk.cli.commands;
import com.beust.jcommander.Parameter;
import com.beust.jcommander.Parameters;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import java.io.IOException;
import java.util.List;
import org.apache.crunch.DoFn;
import org.apache.crunch.PipelineResult;
import org.kitesdk.compat.DynConstructors;
import org.kitesdk.data.DatasetException;
import org.kitesdk.data.View;
import org.kitesdk.tools.CopyTask;
import org.kitesdk.tools.TaskUtil;
import org.kitesdk.tools.TransformTask;
import org.slf4j.Logger;
import static org.apache.avro.generic.GenericData.Record;
@Parameters(commandDescription=
"Transform records from one Dataset and store them in another")
public class TransformCommand extends BaseDatasetCommand {
public TransformCommand(Logger console) {
super(console);
}
@Parameter(description="<source dataset> <destination dataset>")
List<String> datasets;
@Parameter(names={"--no-compaction"},
description="Copy to output directly, without compacting the data")
boolean noCompaction = false;
@Parameter(names={"--num-writers"},
description="The number of writer processes to use")
int numWriters = -1;
@Parameter(names={"--transform"},
description="A transform DoFn class name")
String transform = null;
@Parameter(names="--jar",
description="Add a jar to the runtime classpath")
List<String> jars;
@Override
public int run() throws IOException {
Preconditions.checkArgument(datasets != null && datasets.size() > 1,
"Source and target datasets are required");
Preconditions.checkArgument(datasets.size() == 2,
"Cannot copy multiple datasets");
View<Record> source = load(datasets.get(0), Record.class);
View<Record> dest = load(datasets.get(1), Record.class);
TaskUtil.configure(getConf()).addJars(jars);
TransformTask task;
if (transform != null) {
DoFn<Record, Record> transformFn;
try {
DynConstructors.Ctor<DoFn<Record, Record>> ctor =
new DynConstructors.Builder(DoFn.class)
.loader(loaderForJars(jars))
.impl(transform)
.buildChecked();
transformFn = ctor.newInstance();
} catch (NoSuchMethodException e) {
throw new DatasetException(
"Cannot find no-arg constructor for class: " + transform, e);
}
task = new TransformTask<Record, Record>(source, dest, transformFn);
} else {
task = new CopyTask<Record>(source, dest);
}
task.setConf(getConf());
if (noCompaction) {
task.noCompaction();
}
if (numWriters >= 0) {
task.setNumWriters(numWriters);
}
PipelineResult result = task.run();
if (result.succeeded()) {
console.info("Added {} records to \"{}\"",
task.getCount(), datasets.get(1));
return 0;
} else {
return 1;
}
}
@Override
public List<String> getExamples() {
return Lists.newArrayList(
"# Transform the contents of movies_src using com.example.TransformFn",
"movies_src movies --transform com.example.TransformFn --jar fns.jar"
);
}
}