com.atomikos.persistence.imp.SystemLogImage Maven / Gradle / Ivy
/**
* Copyright (C) 2000-2010 Atomikos
*
* This code ("Atomikos TransactionsEssentials"), by itself,
* is being distributed under the
* Apache License, Version 2.0 ("License"), a copy of which may be found at
* http://www.atomikos.com/licenses/apache-license-2.0.txt .
* You may not use this file except in compliance with the License.
*
* While the License grants certain patent license rights,
* those patent license rights only extend to the use of
* Atomikos TransactionsEssentials by itself.
*
* This code (Atomikos TransactionsEssentials) contains certain interfaces
* in package (namespace) com.atomikos.icatch
* (including com.atomikos.icatch.Participant) which, if implemented, may
* infringe one or more patents held by Atomikos.
* It should be appreciated that you may NOT implement such interfaces;
* licensing to implement these interfaces must be obtained separately from Atomikos.
*
* 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.
*/
package com.atomikos.persistence.imp;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import com.atomikos.icatch.DataSerializable;
import com.atomikos.persistence.ObjectImage;
import com.atomikos.persistence.Recoverable;
public class SystemLogImage implements Recoverable, Externalizable, DataSerializable {
// Force-set the serial version ID to make sure that log
// data can be read.
static final long serialVersionUID = 4153546869295179306L;
protected Recoverable recoverable_ = null;
protected boolean forgettable_ = false;
public SystemLogImage() {
// required for externalizable
// or for writing the terminating entry on restart.
forgettable_ = true;
}
public SystemLogImage(Recoverable recoverable, boolean forgettable) {
recoverable_ = recoverable;
forgettable_ = forgettable;
}
private static final String END_OF_LOG_ENTRY = "END_OF_LOG_ENTRY";
public Object getId() {
if (recoverable_ == null) // terminating entry
return END_OF_LOG_ENTRY;
else
return recoverable_.getId();
}
/**
* Test if an image is forgettable. Needed in case of sequential logs, to write a termination image long after an image was flushed.
*/
public boolean isForgettable() {
return forgettable_;
}
/**
* Get the recoverable. Needed to return the right implementation class to the client!
*
* @return Recoverable The wrapped recoverable.
*/
public ObjectImage getObjectImage() {
return recoverable_.getObjectImage();
}
public Recoverable getRecoverable() {
return recoverable_;
}
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
ObjectImage objectimage = null;
objectimage = (ObjectImage) in.readObject();
recoverable_ = objectimage.restore();
forgettable_ = in.readBoolean();
}
public void writeExternal(ObjectOutput out) throws IOException {
ObjectImage img = recoverable_.getObjectImage();
out.writeObject(img);
out.writeBoolean(forgettable_);
}
public void writeData(DataOutput out) throws IOException {
out.writeBoolean(forgettable_);
((DataSerializable) recoverable_).writeData(out);
}
public void readData(DataInput in) throws IOException {
forgettable_ = in.readBoolean();
recoverable_ = new StateObjectImage();
((DataSerializable) recoverable_).readData(in);
}
}