/*
* Copyright 2016 the original author or authors.
*
* 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.springframework.integration.store;
import java.util.AbstractCollection;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.integration.IntegrationMessageHeaderAccessor;
import org.springframework.messaging.Message;
/**
* @author Artem Bilan
* @since 4.3
*/
class PersistentMessageGroup implements MessageGroup {
private static final Log logger = LogFactory.getLog(PersistentMessageGroup.class);
private final MessageGroupStore messageGroupStore;
private final Collection<Message<?>> messages = new PersistentCollection();
private final MessageGroup original;
private volatile Message<?> oneMessage;
private volatile int size;
PersistentMessageGroup(MessageGroupStore messageGroupStore, MessageGroup original) {
this.messageGroupStore = messageGroupStore;
this.original = original;
}
public void setSize(int size) {
this.size = size;
}
@Override
public Collection<Message<?>> getMessages() {
return Collections.unmodifiableCollection(this.messages);
}
@Override
public Message<?> getOne() {
if (this.oneMessage == null) {
synchronized (this) {
if (this.oneMessage == null) {
if (logger.isDebugEnabled()) {
logger.debug("Lazy loading of one message for messageGroup: " + this.original.getGroupId());
}
this.oneMessage = this.messageGroupStore.getOneMessageFromGroup(this.original.getGroupId());
}
}
}
return this.oneMessage;
}
@Override
public int getSequenceSize() {
if (size() == 0) {
return 0;
}
else {
Message<?> message = getOne();
if (message != null) {
Integer sequenceSize = message.getHeaders()
.get(IntegrationMessageHeaderAccessor.SEQUENCE_SIZE, Integer.class);
return (sequenceSize != null ? sequenceSize : 0);
}
else {
return 0;
}
}
}
@Override
public int size() {
if (this.size == 0) {
synchronized (this) {
if (this.size == 0) {
if (logger.isDebugEnabled()) {
logger.debug("Lazy loading of group size for messageGroup: " + this.original.getGroupId());
}
this.size = this.messageGroupStore.messageGroupSize(this.original.getGroupId());
}
}
}
return this.size;
}
@Override
public Object getGroupId() {
return this.original.getGroupId();
}
@Override
public boolean canAdd(Message<?> message) {
return this.original.canAdd(message);
}
@Override
public int getLastReleasedMessageSequenceNumber() {
return this.original.getLastReleasedMessageSequenceNumber();
}
@Override
public boolean isComplete() {
return this.original.isComplete();
}
@Override
public void complete() {
this.original.complete();
}
@Override
public long getTimestamp() {
return this.original.getTimestamp();
}
@Override
public long getLastModified() {
return this.original.getLastModified();
}
@Override
public void setLastModified(long lastModified) {
this.original.setLastModified(lastModified);
}
@Override
public void add(Message<?> messageToAdd) {
this.original.add(messageToAdd);
}
@Override
public boolean remove(Message<?> messageToRemove) {
return this.original.remove(messageToRemove);
}
@Override
public void setLastReleasedMessageSequenceNumber(int sequenceNumber) {
this.original.setLastReleasedMessageSequenceNumber(sequenceNumber);
}
@Override
public void clear() {
this.original.clear();
}
private final class PersistentCollection extends AbstractCollection<Message<?>> {
private volatile Collection<Message<?>> collection;
PersistentCollection() {
super();
}
private void load() {
if (this.collection == null) {
synchronized (this) {
if (this.collection == null) {
Object groupId = PersistentMessageGroup.this.original.getGroupId();
if (logger.isDebugEnabled()) {
logger.debug("Lazy loading of messages for messageGroup: " + groupId);
}
this.collection = PersistentMessageGroup.this.messageGroupStore.getMessagesForGroup(groupId);
}
}
}
}
@Override
public boolean contains(Object o) {
load();
return this.collection.contains(o);
}
@Override
public Object[] toArray() {
load();
return this.collection.toArray();
}
@Override
public <T> T[] toArray(T[] a) {
load();
return this.collection.toArray(a);
}
@Override
public boolean containsAll(Collection<?> c) {
load();
return this.collection.containsAll(c);
}
@Override
public Iterator<Message<?>> iterator() {
load();
return this.collection.iterator();
}
@Override
public int size() {
return PersistentMessageGroup.this.size();
}
}
}