/**
* The Logic Lab
* @author jpk
* @since Sep 16, 2009
*/
package com.tll.dao.db4o.test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springextensions.db4o.Db4oTransactionManager;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.DefaultTransactionDefinition;
import com.db4o.EmbeddedObjectContainer;
import com.google.inject.Inject;
import com.tll.dao.IDbTrans;
/**
* Db4oTrans
* @author jpk
*/
public class Db4oTrans implements IDbTrans {
private static final Logger log = LoggerFactory.getLogger(Db4oTrans.class);
/**
* The trans manager.
*/
private Db4oTransactionManager tm;
/**
* Used to check if a transaction is in progress only when using Spring
* transaction management.
*/
private TransactionStatus transStatus;
/**
* Flag used in place of {@link #transStatus} when Spring transaction
* management is NOT employed.
*/
private boolean transStarted = false;
/**
* Home-baked support for committing a transaction analagous to Spring's
* setComplete() test related method.
*/
private boolean transCompleteFlag = false;
private final EmbeddedObjectContainer oc;
/**
* Constructor
* @param oc The required db4o object container
*/
@Inject
public Db4oTrans(EmbeddedObjectContainer oc) {
super();
this.oc = oc;
}
@Override
public boolean isGlobalTrans() {
return true;
}
/**
* Hook to [re-]set the {@link EmbeddedObjectContainer} ref.
* @param oc the object container to set
*/
public void setObjectContainer(EmbeddedObjectContainer oc) {
getTransMgr().setObjectContainer(oc);
}
@Override
public void startTrans() throws IllegalStateException {
if(isTransStarted()) {
throw new IllegalStateException("Transaction already started.");
}
final DefaultTransactionDefinition def = new DefaultTransactionDefinition();
def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
transStatus = getTransMgr().getTransaction(def);
transStarted = true;
}
@Override
public void endTrans() throws IllegalStateException {
if(!isTransStarted()) {
throw new IllegalStateException("No transaction in progress");
}
if(transCompleteFlag) {
getTransMgr().commit(transStatus);
transCompleteFlag = false;
}
else {
getTransMgr().rollback(transStatus);
}
transStarted = false;
transStatus = null;
}
@Override
public void setComplete() throws IllegalStateException {
transCompleteFlag = true;
}
@Override
public boolean isTransStarted() {
return transStarted;
}
/**
* @return The lazily instantiated db level trans manager.
*/
private Db4oTransactionManager getTransMgr() {
if(tm == null) {
final Db4oTransactionManager db4oTm = new Db4oTransactionManager(oc);
// set the transaction timeout
final int timeout = 60 * 4; // 4 mins
db4oTm.setDefaultTimeout(timeout);
log.info("Set DB4O default transaction timeout to: " + timeout);
// validate configuration
try {
db4oTm.afterPropertiesSet();
}
catch(final Exception e) {
throw new IllegalStateException(e);
}
this.tm = db4oTm;
}
return tm;
}
}