org.h2.store.InDoubtTransaction Maven / Gradle / Ivy
/*
* Copyright 2004-2011 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.store;
import org.h2.message.DbException;
/**
* Represents an in-doubt transaction (a transaction in the prepare phase).
*/
public class InDoubtTransaction {
/**
* The transaction state meaning this transaction is not committed yet, but
* also not rolled back (in-doubt).
*/
public static final int IN_DOUBT = 0;
/**
* The transaction state meaning this transaction is committed.
*/
public static final int COMMIT = 1;
/**
* The transaction state meaning this transaction is rolled back.
*/
public static final int ROLLBACK = 2;
// TODO 2-phase-commit: document sql statements and metadata table
private final PageStore store;
private final int sessionId;
private final int pos;
private final String transaction;
private int state;
/**
* Create a new in-doubt transaction info object.
*
* @param store the page store
* @param sessionId the session id
* @param pos the position
* @param transaction the transaction name
*/
public InDoubtTransaction(PageStore store, int sessionId, int pos, String transaction) {
this.store = store;
this.sessionId = sessionId;
this.pos = pos;
this.transaction = transaction;
this.state = IN_DOUBT;
}
/**
* Change the state of this transaction.
* This will also update the transaction log.
*
* @param state the new state
*/
public void setState(int state) {
switch(state) {
case COMMIT:
store.setInDoubtTransactionState(sessionId, pos, true);
break;
case ROLLBACK:
store.setInDoubtTransactionState(sessionId, pos, false);
break;
default:
DbException.throwInternalError("state="+state);
}
this.state = state;
}
/**
* Get the state of this transaction as a text.
*
* @return the transaction state text
*/
public String getState() {
switch(state) {
case IN_DOUBT:
return "IN_DOUBT";
case COMMIT:
return "COMMIT";
case ROLLBACK:
return "ROLLBACK";
default:
throw DbException.throwInternalError("state="+state);
}
}
/**
* Get the name of the transaction.
*
* @return the transaction name
*/
public String getTransaction() {
return transaction;
}
}