libraries/eventsourcing/src/main/java/org/apache/zest/library/eventsourcing/domain/source/helper/DomainEventTrackerConfiguration.java

/**
 *
 * 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.apache.zest.library.eventsourcing.domain.source.helper;

import org.apache.zest.api.common.UseDefaults;
import org.apache.zest.api.configuration.ConfigurationComposite;
import org.apache.zest.api.configuration.Enabled;
import org.apache.zest.api.property.Property;

/**
 * Configuration that a service doing event tracking must have. Let the configuration
 * of the service extend this one.
 */
public interface DomainEventTrackerConfiguration
        extends ConfigurationComposite, Enabled
{
    /**
     * A count of how many events have been read already. Call EventStore.events(lastOffset,{limit}) to get
     * the next set of events.
     *
     * @return count of how many events have been read already.
     */
    @UseDefaults
    Property<Long> lastOffset();
}