/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.epl.variable;
/**
* A wrapper for a thread-local to hold the current version for variables visible for a thread, as well
* as uncommitted values of variables for a thread.
*/
public class VariableVersionThreadLocal
{
private ThreadLocal<VariableVersionThreadEntry> perThreadVersion;
/**
* Ctor.
*/
public VariableVersionThreadLocal()
{
perThreadVersion = new ThreadLocal<VariableVersionThreadEntry>()
{
protected synchronized VariableVersionThreadEntry initialValue()
{
return new VariableVersionThreadEntry(0, null);
}
};
}
/**
* Returns the version and uncommitted values for the current thread.
* @return entry for current thread
*/
public VariableVersionThreadEntry getCurrentThread()
{
VariableVersionThreadEntry entry = perThreadVersion.get();
if (entry == null)
{
entry = new VariableVersionThreadEntry(0, null);
perThreadVersion.set(entry);
}
return entry;
}
}