/*
* Copyright 2002-2016 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.Collection;
import org.springframework.messaging.Message;
/**
* A group of messages that are correlated with each other and should be processed in the same context.
* <p>
* The message group allows implementations to be mutable, but this behavior is optional. Implementations should take
* care to document their thread safety and mutability.
*
* @author Dave Syer
* @author Oleg Zhurakousky
* @author Gary Russell
* @author Artem Bilan
*/
public interface MessageGroup {
/**
* Query if the message can be added.
*
* @param message The message.
* @return true if the message can be added.
*/
boolean canAdd(Message<?> message);
/**
* Add the message to this group.
* @param messageToAdd the message to add.
* @since 4.3
*/
void add(Message<?> messageToAdd);
/**
* Remove the message from this group.
* @param messageToRemove the message to remove.
* @return {@code true} if a message was removed.
* @since 4.3
*/
boolean remove(Message<?> messageToRemove);
/**
* Returns all available Messages from the group at the time of invocation
*
* @return The messages.
*/
Collection<Message<?>> getMessages();
/**
* @return the key that links these messages together
*/
Object getGroupId();
/**
* @return the sequenceNumber of the last released message. Used in Resequencer use cases only
*/
int getLastReleasedMessageSequenceNumber();
void setLastReleasedMessageSequenceNumber(int sequenceNumber);
/**
* @return true if the group is complete (i.e. no more messages are expected to be added)
*/
boolean isComplete();
/**
* Complete the group.
*/
void complete();
/**
* @return the size of the sequence expected 0 if unknown
*/
int getSequenceSize();
/**
* @return the total number of messages in this group
*/
int size();
/**
* @return a single message from the group
*/
Message<?> getOne();
/**
* @return the timestamp (milliseconds since epoch) associated with the creation of this group
*/
long getTimestamp();
/**
* @return the timestamp (milliseconds since epoch) associated with the time this group was last updated
*/
long getLastModified();
void setLastModified(long lastModified);
void clear();
}