| /** |
| * |
| * Copyright 2009-2010 Rickard Öberg AB |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.qi4j.library.eventsourcing.domain.source; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.locks.Lock; |
| import java.util.concurrent.locks.ReentrantLock; |
| import org.qi4j.api.entity.Identity; |
| import org.qi4j.api.injection.scope.Structure; |
| import org.qi4j.api.injection.scope.This; |
| import org.qi4j.api.structure.Module; |
| import org.qi4j.api.type.ValueType; |
| import org.qi4j.io.Output; |
| import org.qi4j.io.Receiver; |
| import org.qi4j.io.Sender; |
| import org.qi4j.library.eventsourcing.domain.api.DomainEventValue; |
| import org.qi4j.library.eventsourcing.domain.api.UnitOfWorkDomainEventsValue; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import static java.util.Collections.synchronizedList; |
| |
| /** |
| * Base implementation for EventStores. |
| */ |
| public abstract class AbstractEventStoreMixin |
| implements EventStore, EventStream, EventStoreActivation |
| { |
| @This |
| protected Identity identity; |
| |
| protected Logger logger; |
| protected ValueType domainEventType; |
| protected ValueType eventsType; |
| |
| protected Lock lock = new ReentrantLock(); |
| |
| @Structure |
| protected Module module; |
| |
| private ExecutorService transactionNotifier; |
| |
| final private List<UnitOfWorkEventsListener> listeners = synchronizedList( new ArrayList<UnitOfWorkEventsListener>() ); |
| |
| @Override |
| public void activateEventStore() throws Exception |
| { |
| logger = LoggerFactory.getLogger( identity.identity().get() ); |
| |
| domainEventType = module.valueDescriptor( DomainEventValue.class.getName() ).valueType(); |
| eventsType = module.valueDescriptor( UnitOfWorkDomainEventsValue.class.getName() ).valueType(); |
| |
| transactionNotifier = Executors.newSingleThreadExecutor(); |
| } |
| |
| @Override |
| public void passivateEventStore() throws Exception |
| { |
| transactionNotifier.shutdown(); |
| transactionNotifier.awaitTermination( 10000, TimeUnit.MILLISECONDS ); |
| } |
| |
| // UnitOfWorkEventsVisitor implementation |
| // This is how transactions are put into the store |
| |
| |
| @Override |
| public Output<UnitOfWorkDomainEventsValue, IOException> storeEvents() |
| { |
| final Output<UnitOfWorkDomainEventsValue, IOException> storeOutput = storeEvents0(); |
| |
| return new Output<UnitOfWorkDomainEventsValue, IOException>() |
| { |
| @Override |
| public <SenderThrowableType extends Throwable> void receiveFrom( final Sender<? extends UnitOfWorkDomainEventsValue, SenderThrowableType> sender ) throws IOException, SenderThrowableType |
| { |
| final List<UnitOfWorkDomainEventsValue> events = new ArrayList<UnitOfWorkDomainEventsValue>( ); |
| lock(); |
| try |
| { |
| storeOutput.receiveFrom(new Sender<UnitOfWorkDomainEventsValue, SenderThrowableType>() |
| { |
| @Override |
| public <ReceiverThrowableType extends Throwable> void sendTo( final Receiver<? super UnitOfWorkDomainEventsValue, ReceiverThrowableType> receiver ) throws ReceiverThrowableType, SenderThrowableType |
| { |
| sender.sendTo( new Receiver<UnitOfWorkDomainEventsValue, ReceiverThrowableType>() |
| { |
| @Override |
| public void receive( UnitOfWorkDomainEventsValue item ) throws ReceiverThrowableType |
| { |
| receiver.receive( item ); |
| events.add( item ); |
| } |
| }); |
| } |
| }); |
| |
| } finally |
| { |
| lock.unlock(); |
| } |
| |
| // Notify listeners |
| transactionNotifier.submit( new Runnable() |
| { |
| @Override |
| public void run() |
| { |
| synchronized(listeners) |
| { |
| for( UnitOfWorkEventsListener listener : listeners ) |
| { |
| try |
| { |
| listener.notifyTransactions( events ); |
| } catch( Exception e ) |
| { |
| logger.warn( "Could not notify event listener", e ); |
| } |
| } |
| } |
| } |
| } ); |
| } |
| }; |
| } |
| |
| // EventStream implementation |
| @Override |
| public void registerListener( UnitOfWorkEventsListener subscriber ) |
| { |
| listeners.add( subscriber ); |
| } |
| |
| @Override |
| public void unregisterListener( UnitOfWorkEventsListener subscriber ) |
| { |
| listeners.remove( subscriber ); |
| } |
| |
| abstract protected Output<UnitOfWorkDomainEventsValue, IOException> storeEvents0(); |
| |
| /** |
| * Fix for this bug: |
| * http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6822370 |
| */ |
| protected void lock() |
| { |
| while (true) |
| { |
| try |
| { |
| lock.tryLock( 1000, TimeUnit.MILLISECONDS ); |
| break; |
| } catch (InterruptedException e) |
| { |
| // Try again |
| } |
| } |
| } |
| } |