/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* 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 eu.stratosphere.nephele.jobgraph;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.FileNotFoundException;
import java.io.IOException;
import eu.stratosphere.configuration.IllegalConfigurationException;
import eu.stratosphere.core.fs.FileStatus;
import eu.stratosphere.core.fs.FileSystem;
import eu.stratosphere.core.fs.Path;
import eu.stratosphere.nephele.template.AbstractFileOutputTask;
import eu.stratosphere.nephele.template.AbstractInvokable;
/**
* A JobFileOutputVertex is a specific subtype of a {@link AbstractJobOutputVertex} and is designed
* for Nephele tasks which write data to a local or distributed file system. As every job output vertex
* A JobFileOutputVertex must not have any further output.
*
*/
public class JobFileOutputVertex extends AbstractJobOutputVertex {
/**
* The path pointing to the output file/directory.
*/
private Path path = null;
/**
* Creates a new job file output vertex with the specified name.
*
* @param name
* the name of the new job file output vertex
* @param id
* the ID of this vertex
* @param jobGraph
* the job graph this vertex belongs to
*/
public JobFileOutputVertex(final String name, final JobVertexID id, final JobGraph jobGraph) {
super(name, id, jobGraph);
}
/**
* Creates a new job file output vertex with the specified name.
*
* @param name
* the name of the new job file output vertex
* @param jobGraph
* the job graph this vertex belongs to
*/
public JobFileOutputVertex(final String name, final JobGraph jobGraph) {
super(name, null, jobGraph);
}
/**
* Creates a new job file input vertex.
*
* @param jobGraph
* the job graph this vertex belongs to
*/
public JobFileOutputVertex(final JobGraph jobGraph) {
super(null, null, jobGraph);
}
/**
* Sets the path of the file the job file input vertex's task should write to.
*
* @param path
* the path of the file the job file input vertex's task should write to
*/
public void setFilePath(final Path path) {
this.path = path;
}
/**
* Returns the path of the file the job file output vertex's task should write to.
*
* @return the path of the file the job file output vertex's task should write to or <code>null</code> if no path
* has yet been set
*/
public Path getFilePath() {
return this.path;
}
/**
* Sets the class of the vertex's output task.
*
* @param outputClass
* the class of the vertex's output task.
*/
public void setFileOutputClass(final Class<? extends AbstractFileOutputTask> outputClass) {
this.invokableClass = outputClass;
}
/**
* Returns the class of the vertex's output task.
*
* @return the class of the vertex's output task or <code>null</code> if no task has yet been set
*/
@SuppressWarnings("unchecked")
public Class<? extends AbstractFileOutputTask> getFileOutputClass() {
return (Class<? extends AbstractFileOutputTask>) this.invokableClass;
}
@Override
public void read(final DataInput in) throws IOException {
super.read(in);
// Read path of the input file
boolean isNotNull = in.readBoolean();
if (isNotNull) {
this.path = new Path();
this.path.read(in);
}
}
@Override
public void write(final DataOutput out) throws IOException {
super.write(out);
// Write out the path of the input file
if (this.path == null) {
out.writeBoolean(false);
} else {
out.writeBoolean(true);
this.path.write(out);
}
}
@Override
public void checkConfiguration(final AbstractInvokable invokable) throws IllegalConfigurationException {
// Check if the user has specified a path
if (this.path == null) {
throw new IllegalConfigurationException(this.getName() + " does not specify an output path");
}
super.checkConfiguration(invokable);
}
@Override
public int getMaximumNumberOfSubtasks(final AbstractInvokable invokable) {
if (this.path == null) {
return 0;
}
// Check if the path is valid
try {
final FileSystem fs = path.getFileSystem();
try {
final FileStatus f = fs.getFileStatus(path);
if (f == null) {
return 1;
}
// If the path points to a directory we allow an infinity number of subtasks
if (f.isDir()) {
return -1;
}
} catch (FileNotFoundException fnfex) {
// The exception is thrown if the requested file/directory does not exist.
// if the degree of parallelism is > 1, we create a directory for this path
if (getNumberOfSubtasks() > 1) {
fs.mkdirs(path);
return -1;
} else {
// a none existing file and a degree of parallelism that is one
return 1;
}
}
} catch (IOException e) {
// any other kind of I/O exception: we assume only a degree of one here
return 1;
}
return 1;
}
}