com.github.rahulsom.grooves.queries.TemporalQuery Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of grooves-api Show documentation

APIs that help in computation of Grooves based Snapshots

The newest version!

package com.github.rahulsom.grooves.queries;

import com.github.rahulsom.grooves.api.events.BaseEvent;
import com.github.rahulsom.grooves.api.snapshots.TemporalSnapshot;
import org.jetbrains.annotations.NotNull;
import org.reactivestreams.Publisher;

import java.util.Date;

/**
 * A query that produces a {@link TemporalSnapshot}.
 *
 * @param   The aggregate over which the query executes
 * @param     The type of the EventT's id field
 * @param       The type of the event
 * @param  The type of the SnapshotT's id field
 * @param    The type of the snapshot
 * @author Rahul Somasunderam
 */
public interface TemporalQuery<
        AggregateT,
        EventIdT,
        EventT extends BaseEvent,
        SnapshotIdT,
        SnapshotT extends TemporalSnapshot> {
    /**
     * Computes a snapshot for specified version of an aggregate.
     *
     * @param aggregate The aggregate
     * @param moment    The moment at which the snapshot is desired
     *
     * @return A Publisher that returns at most one Snapshot
     */
    @NotNull Publisher computeSnapshot(
            @NotNull AggregateT aggregate, @NotNull Date moment);

    /**
     * Computes a snapshot for specified version of an aggregate.
     *
     * @param aggregate The aggregate
     * @param moment    The moment at which the snapshot is desired
     * @param redirect  If there has been a deprecation, redirect to the current aggregate's
     *                  snapshot. Defaults to true.
     *
     * @return An Optional SnapshotType. Empty if it cannot be computed.
     */
    @NotNull Publisher computeSnapshot(
            @NotNull AggregateT aggregate, @NotNull Date moment, boolean redirect);

}