/***********************************************************************************************************************
* 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.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.AbstractFileInputTask;
import eu.stratosphere.nephele.template.AbstractInvokable;
import eu.stratosphere.util.StringUtils;
/**
* A JobFileInputVertex is a specific subtype of a {@link AbstractJobInputVertex} and is designed
* for Nephele tasks which read data from a local or distributed file system. As every job input vertex
* A JobFileInputVertex must not have any further input.
*
*/
public final class JobFileInputVertex extends AbstractJobInputVertex {
/**
* The path pointing to the input file/directory.
*/
private Path path = null;
/**
* Creates a new job file input vertex with the specified name.
*
* @param name
* the name of the new job file input vertex
* @param id
* the ID of this vertex
* @param jobGraph
* the job graph this vertex belongs to
*/
public JobFileInputVertex(final String name, final JobVertexID id, final JobGraph jobGraph) {
super(name, id, jobGraph);
}
/**
* Creates a new job file input vertex with the specified name.
*
* @param name
* the name of the new job file input vertex
* @param jobGraph
* the job graph this vertex belongs to
*/
public JobFileInputVertex(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 JobFileInputVertex(final JobGraph jobGraph) {
super(null, null, jobGraph);
}
/**
* Sets the path of the file the job file input vertex's task should read from.
*
* @param path
* the path of the file the job file input vertex's task should read from
*/
public void setFilePath(final Path path) {
this.path = path;
}
/**
* Returns the path of the file the job file input vertex's task should read from.
*
* @return the path of the file the job file input vertex's task should read from or <code>null</code> if no path
* has yet been set
*/
public Path getFilePath() {
return this.path;
}
/**
* Sets the class of the vertex's input task.
*
* @param inputClass
* the class of the vertex's input task.
*/
public void setFileInputClass(final Class<? extends AbstractFileInputTask> inputClass) {
this.invokableClass = inputClass;
}
/**
* Returns the class of the vertex's input task.
*
* @return the class of the vertex's input task or <code>null</code> if no task has yet been set
*/
@SuppressWarnings("unchecked")
public Class<? extends AbstractFileInputTask> getFileInputClass() {
return (Class<? extends AbstractFileInputTask>) this.invokableClass;
}
@Override
public void read(final DataInput in) throws IOException {
super.read(in);
// Read path of the input file
final 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 input path");
}
// Check if the path is valid
try {
final FileSystem fs = this.path.getFileSystem();
final FileStatus f = fs.getFileStatus(this.path);
if (f == null) {
throw new IOException(this.path.toString() + " led to a null object");
}
} catch (IOException e) {
throw new IllegalConfigurationException("Cannot access file or directory: "
+ StringUtils.stringifyException(e));
}
// register the path in the configuration
invokable.getTaskConfiguration()
.setString(AbstractFileInputTask.INPUT_PATH_CONFIG_KEY, this.path.toString());
// Finally, see if the task itself has a valid configuration
super.checkConfiguration(invokable);
}
@Override
public int getMaximumNumberOfSubtasks(final AbstractInvokable invokable) {
int numberOfBlocks = -1;
if (this.path == null) {
return -1;
}
try {
final FileSystem fs = this.path.getFileSystem();
final FileStatus f = fs.getFileStatus(this.path);
numberOfBlocks = fs.getNumberOfBlocks(f);
} catch (IOException e) {
return -1;
}
return (int) Math.min(numberOfBlocks, invokable.getMaximumNumberOfSubtasks());
}
}