/*
* ArffFileStream.java
* Copyright (C) 2007 University of Waikato, Hamilton, New Zealand
* @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package tr.gov.ulakbim.jDenetX.streams;
import tr.gov.ulakbim.jDenetX.core.InputStreamProgressMonitor;
import tr.gov.ulakbim.jDenetX.core.InstancesHeader;
import tr.gov.ulakbim.jDenetX.core.ObjectRepository;
import tr.gov.ulakbim.jDenetX.options.AbstractOptionHandler;
import tr.gov.ulakbim.jDenetX.options.FileOption;
import tr.gov.ulakbim.jDenetX.options.IntOption;
import tr.gov.ulakbim.jDenetX.tasks.TaskMonitor;
import weka.core.Instance;
import weka.core.Instances;
import java.io.*;
public class ArffFileStream extends AbstractOptionHandler implements
InstanceStream {
@Override
public String getPurposeString() {
return "A stream read from an ARFF file.";
}
private static final long serialVersionUID = 1L;
public FileOption arffFileOption = new FileOption("arffFile", 'f',
"ARFF file to load.",
null, "arff", false);
public IntOption classIndexOption = new IntOption(
"classIndex",
'c',
"Class index of data. 0 for none or -1 for last attribute in file.",
-1, -1, Integer.MAX_VALUE);
protected Instances instances;
protected Reader fileReader;
protected boolean hitEndOfFile;
protected Instance lastInstanceRead;
protected int numInstancesRead;
protected InputStreamProgressMonitor fileProgressMonitor;
public ArffFileStream() { }
public ArffFileStream(String arffFileName, int classIndex) {
this.arffFileOption.setValue(arffFileName);
this.classIndexOption.setValue(classIndex);
restart();
}
@Override
public void prepareForUseImpl(TaskMonitor monitor,
ObjectRepository repository) {
restart();
}
public InstancesHeader getHeader() {
return new InstancesHeader(this.instances);
}
public long estimatedRemainingInstances() {
double progressFraction = this.fileProgressMonitor
.getProgressFraction();
if ((progressFraction > 0.0) && (this.numInstancesRead > 0)) {
return (long) ((this.numInstancesRead / progressFraction) - this.numInstancesRead);
}
return -1;
}
public boolean hasMoreInstances() {
return !this.hitEndOfFile;
}
public Instance nextInstance() {
Instance prevInstance = this.lastInstanceRead;
this.hitEndOfFile = !readNextInstanceFromFile();
return prevInstance;
}
public boolean isRestartable() {
return true;
}
public void restart() {
try {
if (this.fileReader != null) {
this.fileReader.close();
}
InputStream fileStream = new FileInputStream(this.arffFileOption
.getFile());
this.fileProgressMonitor = new InputStreamProgressMonitor(
fileStream);
this.fileReader = new BufferedReader(new InputStreamReader(
this.fileProgressMonitor));
this.instances = new Instances(this.fileReader, 1);
if (this.classIndexOption.getValue() < 0) {
this.instances
.setClassIndex(this.instances.numAttributes() - 1);
} else if (this.classIndexOption.getValue() > 0) {
this.instances
.setClassIndex(this.classIndexOption.getValue() - 1);
}
this.numInstancesRead = 0;
this.lastInstanceRead = null;
this.hitEndOfFile = !readNextInstanceFromFile();
} catch (IOException ioe) {
throw new RuntimeException("ArffFileStream restart failed.", ioe);
}
}
protected boolean readNextInstanceFromFile() {
try {
if (this.instances.readInstance(this.fileReader)) {
this.lastInstanceRead = this.instances.instance(0);
this.instances.delete(); // keep instances clean
this.numInstancesRead++;
return true;
}
if (this.fileReader != null) {
this.fileReader.close();
this.fileReader = null;
}
return false;
} catch (IOException ioe) {
throw new RuntimeException(
"ArffFileStream failed to read instance from stream.", ioe);
}
}
public void getDescription(StringBuilder sb, int indent) {
// TODO Auto-generated method stub
}
}