package org.drools.persistence.session;
import java.lang.reflect.Constructor;
import java.util.Collections;
import java.util.Date;
import java.util.IdentityHashMap;
import java.util.Map;
import org.drools.KnowledgeBase;
import org.drools.RuleBase;
import org.drools.SessionConfiguration;
import org.drools.command.Command;
import org.drools.command.Context;
import org.drools.command.impl.ContextImpl;
import org.drools.command.impl.GenericCommand;
import org.drools.command.impl.KnowledgeCommandContext;
import org.drools.command.runtime.DisposeCommand;
import org.drools.common.EndOperationListener;
import org.drools.common.InternalKnowledgeRuntime;
import org.drools.impl.KnowledgeBaseImpl;
import org.drools.persistence.processinstance.JPAWorkItemManager;
import org.drools.runtime.Environment;
import org.drools.runtime.EnvironmentName;
import org.drools.runtime.KnowledgeSessionConfiguration;
import org.drools.runtime.StatefulKnowledgeSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SingleSessionCommandService
implements
org.drools.command.SingleSessionCommandService {
Logger logger = LoggerFactory.getLogger( getClass() );
private SessionInfo sessionInfo;
private JPASessionMarshallingHelper marshallingHelper;
private StatefulKnowledgeSession ksession;
private Environment env;
private KnowledgeCommandContext kContext;
private TransactionManager txm;
private JpaManager jpm;
private volatile boolean doRollback;
private static Map<Object, Object> synchronizations = Collections.synchronizedMap( new IdentityHashMap<Object, Object>() );
public static Map<Object, Object> txManagerClasses = Collections.synchronizedMap( new IdentityHashMap<Object, Object>() );
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 ),
conf,
env );
}
public SingleSessionCommandService(int sessionId,
RuleBase ruleBase,
SessionConfiguration conf,
Environment env) {
this( sessionId,
new KnowledgeBaseImpl( ruleBase ),
conf,
env );
}
public SingleSessionCommandService(KnowledgeBase kbase,
KnowledgeSessionConfiguration conf,
Environment env) {
if ( conf == null ) {
conf = new SessionConfiguration();
}
this.env = env;
checkEnvironment( this.env );
this.sessionInfo = new SessionInfo();
initTransactionManager( this.env );
// create session but bypass command service
this.ksession = kbase.newStatefulKnowledgeSession(conf, this.env);
this.kContext = new KnowledgeCommandContext( new ContextImpl( "ksession",
null ),
null,
null,
this.ksession,
null );
((JpaJDKTimerService) ((InternalKnowledgeRuntime) ksession).getTimerService()).setCommandService( this );
this.marshallingHelper = new JPASessionMarshallingHelper( this.ksession,
conf );
this.sessionInfo.setJPASessionMashallingHelper( this.marshallingHelper );
((InternalKnowledgeRuntime) this.ksession).setEndOperationListener( new EndOperationListenerImpl( this.sessionInfo ) );
// Use the App scoped EntityManager if the user has provided it, and it is open.
try {
this.txm.begin();
//this.appScopedEntityManager.joinTransaction();
registerRollbackSync();
jpm.getApplicationScopedEntityManager().persist( this.sessionInfo );
this.txm.commit();
} catch ( Exception t1 ) {
try {
this.txm.rollback();
} catch ( Throwable t2 ) {
throw new RuntimeException( "Could not commit session or rollback",
t2 );
}
throw new RuntimeException( "Could not commit session",
t1 );
}
// update the session id to be the same as the session info id
((InternalKnowledgeRuntime) ksession).setId( this.sessionInfo.getId() );
}
public SingleSessionCommandService(int sessionId,
KnowledgeBase kbase,
KnowledgeSessionConfiguration conf,
Environment env) {
if ( conf == null ) {
conf = new SessionConfiguration();
}
this.env = env;
checkEnvironment( this.env );
initTransactionManager( this.env );
initKsession( sessionId,
kbase,
conf );
}
public void initKsession(int sessionId,
KnowledgeBase kbase,
KnowledgeSessionConfiguration conf) {
if ( !doRollback && this.ksession != null ) {
return;
// nothing to initialise
}
this.doRollback = false;
try {
this.sessionInfo = jpm.getApplicationScopedEntityManager().find( SessionInfo.class,
sessionId );
} catch ( Exception e ) {
throw new RuntimeException( "Could not find session data for id " + sessionId,
e );
}
if ( sessionInfo == null ) {
throw new RuntimeException( "Could not find session data for id " + sessionId );
}
if ( this.marshallingHelper == null ) {
// this should only happen when this class is first constructed
this.marshallingHelper = new JPASessionMarshallingHelper( kbase,
conf,
env );
}
this.sessionInfo.setJPASessionMashallingHelper( this.marshallingHelper );
// if this.ksession is null, it'll create a new one, else it'll use the existing one
this.ksession = this.marshallingHelper.loadSnapshot( this.sessionInfo.getData(),
this.ksession );
// update the session id to be the same as the session info id
((InternalKnowledgeRuntime) ksession).setId( this.sessionInfo.getId() );
((InternalKnowledgeRuntime) this.ksession).setEndOperationListener( new EndOperationListenerImpl( this.sessionInfo ) );
((JpaJDKTimerService) ((InternalKnowledgeRuntime) ksession).getTimerService()).setCommandService( this );
if ( this.kContext == null ) {
// this should only happen when this class is first constructed
this.kContext = new KnowledgeCommandContext( new ContextImpl( "ksession",
null ),
null,
null,
this.ksession,
null );
}
}
public void initTransactionManager(Environment env) {
Object tm = env.get( EnvironmentName.TRANSACTION_MANAGER );
if ( tm != null && tm.getClass().getName().startsWith( "org.springframework" ) ) {
try {
Class<?> cls = Class.forName( "org.drools.container.spring.beans.persistence.DroolsSpringTransactionManager" );
Constructor<?> con = cls.getConstructors()[0];
this.txm = (TransactionManager) con.newInstance( tm );
logger.debug( "Instantiating DroolsSpringTransactionManager" );
if ( tm.getClass().getName().toLowerCase().contains( "jpa" ) ) {
// configure spring for JPA and local transactions
cls = Class.forName( "org.drools.container.spring.beans.persistence.DroolsSpringJpaManager" );
con = cls.getConstructors()[0];
this.jpm = ( JpaManager) con.newInstance( new Object[] { this.env } );
} else {
// configure spring for JPA and distributed transactions
}
} catch ( Exception e ) {
logger.warn( "Could not instatiate DroolsSpringTransactionManager" );
throw new RuntimeException( "Could not instatiate org.drools.container.spring.beans.persistence.DroolsSpringTransactionManager", e );
}
} else {
logger.debug( "Instantiating JtaTransactionManager" );
this.txm = new JtaTransactionManager( env.get( EnvironmentName.TRANSACTION ),
env.get( EnvironmentName.TRANSACTION_SYNCHRONIZATION_REGISTRY ),
tm );
this.jpm = new DefaultJpaManager(this.env);
}
}
public static class EndOperationListenerImpl
implements
EndOperationListener {
private SessionInfo info;
public EndOperationListenerImpl(SessionInfo info) {
this.info = info;
}
public void endOperation(InternalKnowledgeRuntime kruntime) {
this.info.setLastModificationDate( new Date( kruntime.getLastIdleTimestamp() ) );
}
}
public Context getContext() {
return this.kContext;
}
public synchronized <T> T execute(Command<T> command) {
try {
txm.begin();
initKsession( this.sessionInfo.getId(),
this.marshallingHelper.getKbase(),
this.marshallingHelper.getConf() );
this.jpm.beginCommandScopedEntityManager();
//this.appScopedEntityManager.joinTransaction();
registerRollbackSync();
T result = ((GenericCommand<T>) command).execute( this.kContext );
txm.commit();
return result;
}catch (RuntimeException re){
rollbackTransaction(re);
throw re;
} catch ( Exception t1 ) {
rollbackTransaction(t1);
throw new RuntimeException("Wrapped exception see cause", t1);
} finally {
if ( command instanceof DisposeCommand ) {
this.jpm.dispose();
}
}
}
private void rollbackTransaction(Exception t1) {
try {
logger.error( "Could not commit session", t1 );
txm.rollback();
} catch ( Exception t2 ) {
logger.error( "Could not rollback", t2 );
throw new RuntimeException( "Could not commit session or rollback", t2 );
}
}
public void dispose() {
if ( ksession != null ) {
ksession.dispose();
}
}
public int getSessionId() {
return sessionInfo.getId();
}
private void registerRollbackSync() {
if ( synchronizations.get( this ) == null ) {
txm.registerTransactionSynchronization( new SynchronizationImpl( this ) );
synchronizations.put( this,
this );
}
}
private static class SynchronizationImpl
implements
TransactionSynchronization {
SingleSessionCommandService service;
public SynchronizationImpl(SingleSessionCommandService service) {
this.service = service;
}
public void afterCompletion(int status) {
if ( status != TransactionManager.STATUS_COMMITTED ) {
this.service.rollback();
}
// always cleanup thread local whatever the result
SingleSessionCommandService.synchronizations.remove( this.service );
this.service.jpm.endCommandScopedEntityManager();
StatefulKnowledgeSession ksession = this.service.ksession;
// clean up cached process and work item instances
if ( ksession != null ) {
((InternalKnowledgeRuntime) ksession).getProcessRuntime().clearProcessInstances();
((JPAWorkItemManager) ksession.getWorkItemManager()).clearWorkItems();
}
}
public void beforeCompletion() {
}
}
private void rollback() {
this.doRollback = true;
}
}