package org.drools.persistence.session;
import java.util.Map;
import javax.naming.InitialContext;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.transaction.RollbackException;
import javax.transaction.Status;
import javax.transaction.Synchronization;
import javax.transaction.SystemException;
import javax.transaction.TransactionManager;
import javax.transaction.UserTransaction;
import org.apache.commons.collections.map.IdentityMap;
import org.drools.KnowledgeBase;
import org.drools.RuleBase;
import org.drools.SessionConfiguration;
import org.drools.StatefulSession;
import org.drools.impl.KnowledgeBaseImpl;
import org.drools.impl.StatefulKnowledgeSessionImpl;
import org.drools.persistence.processinstance.JPAProcessInstanceManager;
import org.drools.persistence.processinstance.JPASignalManager;
import org.drools.persistence.processinstance.JPAWorkItemManager;
import org.drools.process.command.Command;
import org.drools.process.command.CommandService;
import org.drools.reteoo.ReteooStatefulSession;
import org.drools.reteoo.ReteooWorkingMemory;
import org.drools.runtime.Environment;
import org.drools.runtime.EnvironmentName;
import org.drools.runtime.KnowledgeSessionConfiguration;
import org.drools.runtime.StatefulKnowledgeSession;
public class SingleSessionCommandService
implements
CommandService {
private EntityManagerFactory emf;
private EntityManager em;
private SessionInfo sessionInfo;
private JPASessionMarshallingHelper marshallingHelper;
private StatefulSession session;
private StatefulKnowledgeSession ksession;
private Environment env;
public void checkEnvironment(Environment env) {
if ( env.get( EnvironmentName.ENTITY_MANAGER_FACTORY ) == null ) {
throw new IllegalArgumentException( "Environment must have an EntityManagerFactory" );
}
// @TODO log a warning that all transactions will be locally scoped using the EntityTransaction
// if ( env.get( EnvironmentName.TRANSACTION_MANAGER ) == null ) {
// throw new IllegalArgumentException( "Environment must have an EntityManagerFactory" );
// }
}
public SingleSessionCommandService(RuleBase ruleBase,
SessionConfiguration conf,
Environment env) {
this( new KnowledgeBaseImpl( ruleBase ),
(SessionConfiguration) conf,
env );
}
public SingleSessionCommandService(int sessionId,
RuleBase ruleBase,
SessionConfiguration conf,
Environment env) {
this( sessionId,
new KnowledgeBaseImpl( ruleBase ),
(SessionConfiguration) conf,
env );
}
public SingleSessionCommandService(KnowledgeBase kbase,
KnowledgeSessionConfiguration conf,
Environment env) {
if ( conf == null ) {
conf = new SessionConfiguration();
}
this.env = env;
this.sessionInfo = new SessionInfo();
this.session = ((KnowledgeBaseImpl) kbase).ruleBase.newStatefulSession( (SessionConfiguration) conf,
this.env );
this.ksession = new StatefulKnowledgeSessionImpl( (ReteooWorkingMemory) session );
((JPASignalManager) this.session.getSignalManager()).setCommandService( this );
this.marshallingHelper = new JPASessionMarshallingHelper( this.ksession,
conf );
this.sessionInfo.setJPASessionMashallingHelper( this.marshallingHelper );
this.emf = (EntityManagerFactory) env.get( EnvironmentName.ENTITY_MANAGER_FACTORY );
this.em = emf.createEntityManager(); // how can I ensure this is an extended entity?
// System.out.println( ((EntityManagerImpl) this.em).getFlushMode() );
UserTransaction ut = null;
try {
InitialContext ctx = new InitialContext();
ut = (UserTransaction) ctx.lookup( "java:comp/UserTransaction" );
ut.begin();
registerRollbackSync();
this.em.joinTransaction();
this.em.persist( this.sessionInfo );
ut.commit();
} catch ( Throwable t1 ) {
try {
if ( ut != null ) {
ut.rollback();
}
} catch ( Throwable t2 ) {
throw new RuntimeException( "Could not rollback transaction", t2 );
}
throw new RuntimeException( "Could not commit session", t1 );
}
// update the session id to be the same as the session info id
((ReteooStatefulSession) this.session).setId( this.sessionInfo.getId() );
new Thread( new Runnable() {
public void run() {
session.fireUntilHalt();
}
} );
}
public SingleSessionCommandService(int sessionId,
KnowledgeBase kbase,
KnowledgeSessionConfiguration conf,
Environment env) {
if ( conf == null ) {
conf = new SessionConfiguration();
}
this.env = env;
this.emf = (EntityManagerFactory) env.get( EnvironmentName.ENTITY_MANAGER_FACTORY );
this.em = emf.createEntityManager(); // how can I ensure this is an extended entity?
//System.out.println(((EntityManagerImpl) this.em).getFlushMode());
UserTransaction ut = null;
try {
InitialContext ctx = new InitialContext();
ut = (UserTransaction) ctx.lookup( "java:comp/UserTransaction" );
ut.begin();
registerRollbackSync();
this.em.joinTransaction();
sessionInfo = this.em.find( SessionInfo.class, sessionId );
ut.commit();
} catch ( Throwable t1 ) {
try {
if ( ut != null ) {
ut.rollback();
}
throw new RuntimeException( "Could not find session data for id " + sessionId,
t1 );
} catch ( Throwable t2 ) {
throw new RuntimeException( "Could not rollback transaction",
t2 );
}
}
if (sessionInfo == null) {
throw new RuntimeException("Could not find session data for id " + sessionId);
}
this.marshallingHelper = new JPASessionMarshallingHelper( this.sessionInfo,
kbase,
conf,
env );
this.sessionInfo.setJPASessionMashallingHelper( this.marshallingHelper );
this.ksession = this.marshallingHelper.getObject();
this.session = (StatefulSession) ((StatefulKnowledgeSessionImpl) ksession).session;
((JPASignalManager) this.session.getSignalManager()).setCommandService( this );
new Thread( new Runnable() {
public void run() {
session.fireUntilHalt();
}
} );
}
public StatefulSession getSession() {
return this.session;
}
public synchronized <T> T execute(Command<T> command) {
session.halt();
boolean localTransaction = false;
UserTransaction ut = null;
try {
ut = (UserTransaction) new InitialContext().lookup( "java:comp/UserTransaction" );
if ( ut.getStatus() == Status.STATUS_NO_TRANSACTION ) {
// If there is no transaction then start one, we will commit within the same Command
ut.begin();
localTransaction = true;
}
EntityManager localEm = (EntityManager) env.get( EnvironmentName.ENTITY_MANAGER );
if (localEm == null || !localEm.isOpen()) {
localEm = this.emf.createEntityManager(); // no need to call joinTransaction as it will do so if one already exists
this.env.set( EnvironmentName.ENTITY_MANAGER, localEm );
}
if ( this.em == null ) {
// there must have been a rollback to lazily re-initialise the state
this.em = this.emf.createEntityManager();
this.sessionInfo = this.em.find( SessionInfo.class, this.sessionInfo.getId() );
this.sessionInfo.setJPASessionMashallingHelper( this.marshallingHelper );
// have to create a new localEM as an EM part of a transaction cannot do a find.
// this.sessionInfo.rollback();
this.marshallingHelper.loadSnapshot( this.sessionInfo.getData(),
this.ksession );
this.session = (StatefulSession) ((StatefulKnowledgeSessionImpl) this.ksession).session;
}
this.em.joinTransaction();
this.sessionInfo.setDirty();
registerRollbackSync();
T result = command.execute( ( ReteooWorkingMemory ) session );
if ( localTransaction ) {
// it's a locally created transaction so commit
ut.commit();
// cleanup local entity manager
if ( localEm.isOpen() ) {
localEm.close();
}
this.env.set( EnvironmentName.ENTITY_MANAGER, null );
// clean up cached process and work item instances
((JPAProcessInstanceManager) ((ReteooWorkingMemory) session).getProcessInstanceManager()).clearProcessInstances();
((JPAWorkItemManager) ((ReteooWorkingMemory) session).getWorkItemManager()).clearWorkItems();
}
return result;
} catch ( Throwable t1 ) {
t1.printStackTrace();
if ( localTransaction ) {
try {
if ( ut != null ) {
ut.rollback();
}
throw new RuntimeException( "Could not execute command",
t1 );
} catch ( Throwable t2 ) {
throw new RuntimeException( "Could not rollback transaction",
t2 );
}
} else {
throw new RuntimeException( "Could not execute command",
t1 );
}
} finally {
new Thread( new Runnable() {
public void run() {
session.fireUntilHalt();
}
} );
}
}
public void dispose() {
if ( session != null ) {
session.dispose();
}
}
public int getSessionId() {
return sessionInfo.getId();
}
private void registerRollbackSync() throws IllegalStateException,
RollbackException,
SystemException {
TransactionManager txm = (TransactionManager) env.get( EnvironmentName.TRANSACTION_MANAGER );
if ( txm == null ) {
return;
}
Map map = (Map) env.get( "synchronizations" );
if ( map == null ) {
map = new IdentityMap();
env.set( "synchronizations",
map );
}
if ( map.get( this ) == null ) {
txm.getTransaction().registerSynchronization( new SynchronizationImpl() );
map.put( this,
this );
}
// // lazy registration that ensures we registration the rollback just once
// if ( !rollbackRegistered.get() ) {
// TransactionManagerServices.getTransactionManager().getTransaction().registerSynchronization( new SynchronizationImpl( rollbackRegistered,
// ks ) );
// rollbackRegistered.set( true );
// System.out.println( "registered rollback sychronisation" );
// }
}
private class SynchronizationImpl
implements
Synchronization {
public void afterCompletion(int status) {
if ( status != Status.STATUS_COMMITTED ) {
rollback();
}
// always cleanup thread local whatever the result
//rollbackRegistered.remove();
Map map = (Map) env.get( "synchronizations" );
map.remove( SingleSessionCommandService.this );
// cleanup local entity manager
EntityManager localEm = (EntityManager) env.get( EnvironmentName.ENTITY_MANAGER );
if ( localEm != null && localEm.isOpen() ) {
localEm.close();
}
env.set( EnvironmentName.ENTITY_MANAGER, null );
// clean up cached process and work item instances
((JPAProcessInstanceManager) ((ReteooWorkingMemory) session).getProcessInstanceManager()).clearProcessInstances();
((JPAWorkItemManager) ((ReteooWorkingMemory) session).getWorkItemManager()).clearWorkItems();
}
public void beforeCompletion() {
}
}
// public static class SynchronizationImpl
// implements
// Synchronization {
// KnowledgeStore ks;
// ThreadLocal<Boolean> rollbackRegistered;
//
// SynchronizationImpl(ThreadLocal<Boolean> rollbackRegistered,
// KnowledgeStore ks) {
// this.ks = ks;
// this.rollbackRegistered = rollbackRegistered;
// }
//
// public void afterCompletion(int status) {
// if ( status == Status.STATUS_COMMITTED) {
// ks.commit();
// System.out.println( "after with local commit: " + status );
// } else {
// ks.rollback();
// System.out.println( "after with local rollacbk: " + status );
// }
//
// // always cleanup thread local whatever the result
// rollbackRegistered.remove();
// System.out.println( "cleanedup rollback sychronisation" );
// }
//
// public void beforeCompletion() {
// System.out.println( "before " );
// }
//}
private void rollback() {
// with em null, if someone tries to use this session it'll first restore it's state
this.em.close();
this.em = null;
}
}