/*
* 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.
*/
/*
* AbstractSaver.java
* Copyright (C) 2004 University of Waikato, Hamilton, New Zealand
*
*/
package weka.core.converters;
import weka.core.Capabilities;
import weka.core.CapabilitiesHandler;
import weka.core.Instance;
import weka.core.Instances;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
/**
* Abstract class for Saver
*
* @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
* @author Stefan Mutter (mutter@cs.waikato.ac.nz)
* @version $Revision: 5953 $
*/
public abstract class AbstractSaver
implements Saver, CapabilitiesHandler {
/** The write modes */
protected static final int WRITE = 0;
protected static final int WAIT = 1;
protected static final int CANCEL = 2;
protected static final int STRUCTURE_READY = 3;
/** The instances that should be stored */
private Instances m_instances;
/** The current retrieval mode */
protected int m_retrieval;
/** The current write mode */
private int m_writeMode;
/**
* resets the options
*
*/
public void resetOptions(){
m_instances = null;
m_writeMode = WAIT;
}
/** Resets the structure (header information of the instances) */
public void resetStructure(){
m_instances = null;
m_writeMode = WAIT;
}
/**
* Sets the retrieval mode.
*
* @param mode the retrieval mode
*/
public void setRetrieval(int mode) {
m_retrieval = mode;
}
/**
* Gets the retrieval mode.
*
* @return the retrieval mode
*/
protected int getRetrieval() {
return m_retrieval;
}
/**
* Sets the write mode.
*
* @param mode the write mode
*/
protected void setWriteMode(int mode) {
m_writeMode = mode;
}
/**
* Gets the write mode.
*
* @return the write mode
*/
public int getWriteMode() {
return m_writeMode;
}
/**
* Sets instances that should be stored.
*
* @param instances the instances
*/
public void setInstances(Instances instances){
Capabilities cap = getCapabilities();
if (!cap.test(instances))
throw new IllegalArgumentException(cap.getFailReason());
if(m_retrieval == INCREMENTAL){
if(setStructure(instances) == CANCEL)
cancel();
}
else
m_instances = instances;
}
/**
* Gets instances that should be stored.
*
* @return the instances
*/
public Instances getInstances(){
return m_instances;
}
/**
* Default implementation throws an IOException.
*
* @param file the File
* @exception IOException always
*/
public void setDestination(File file) throws IOException {
throw new IOException("Writing to a file not supported");
}
/**
* Default implementation throws an IOException.
*
* @param output the OutputStream
* @exception IOException always
*/
public void setDestination(OutputStream output) throws IOException {
throw new IOException("Writing to an outputstream not supported");
}
/**
* Returns the Capabilities of this saver. Derived savers have to
* override this method to enable capabilities.
*
* @return the capabilities of this object
* @see Capabilities
*/
public Capabilities getCapabilities() {
Capabilities result = new Capabilities(this);
result.setMinimumNumberInstances(0);
return result;
}
/** Sets the strcuture of the instances for the first step of incremental saving.
* The instances only need to have a header.
* @param headerInfo an instances object.
* @return the appropriate write mode
*/
public int setStructure(Instances headerInfo){
Capabilities cap = getCapabilities();
if (!cap.test(headerInfo))
throw new IllegalArgumentException(cap.getFailReason());
if(m_writeMode == WAIT && headerInfo != null){
m_instances = headerInfo;
m_writeMode = STRUCTURE_READY;
}
else{
if((headerInfo == null) || !(m_writeMode == STRUCTURE_READY) || !headerInfo.equalHeaders(m_instances)){
m_instances = null;
if(m_writeMode != WAIT)
System.err.println("A structure cannot be set up during an active incremental saving process.");
m_writeMode = CANCEL;
}
}
return m_writeMode;
}
/** Cancels the incremental saving process if the write mode is CANCEL. */
public void cancel(){
if(m_writeMode == CANCEL)
resetOptions();
}
/** Method for incremental saving.
* Standard behaviour: no incremental saving is possible, therefore throw an
* IOException.
* An incremental saving process is stopped by calling this method with null.
* @param i the instance to be saved
* @throws IOException IOEXception if the instance acnnot be written to the specified destination
*/
public void writeIncremental(Instance i) throws IOException{
throw new IOException("No Incremental saving possible.");
}
/** Writes to a file in batch mode
* To be overridden.
* @throws IOException exception if writting is not possible
*/
public abstract void writeBatch() throws IOException;
/**
* Default implementation throws an IOException.
*
* @exception IOException always
*/
public String getFileExtension() throws Exception{
throw new Exception("Saving in a file not supported.");
}
/**
* Default implementation throws an IOException.
*
* @param file the File
* @exception IOException always
*/
public void setFile(File file)throws IOException{
throw new IOException("Saving in a file not supported.");
}
/**
* Default implementation throws an IOException.
*
* @param prefix the file prefix
* @exception IOException always
*/
public void setFilePrefix(String prefix) throws Exception{
throw new Exception("Saving in a file not supported.");
}
/**
* Default implementation throws an IOException.
*
* @exception IOException always
*/
public String filePrefix() throws Exception{
throw new Exception("Saving in a file not supported.");
}
/**
* Default implementation throws an IOException.
*
* @param dir the name of the directory to save in
* @exception IOException always
*/
public void setDir(String dir) throws IOException{
throw new IOException("Saving in a file not supported.");
}
/**
* Default implementation throws an IOException.
*
* @param relationName
* @param add
* @exception IOException always
*/
public void setDirAndPrefix(String relationName, String add) throws IOException{
throw new IOException("Saving in a file not supported.");
}
/**
* Default implementation throws an IOException.
*
* @exception IOException always
*/
public String retrieveDir() throws IOException{
throw new IOException("Saving in a file not supported.");
}
}