001package ca.uhn.fhir.jpa.subscription.api;
002
003/*-
004 * #%L
005 * HAPI FHIR Subscription Server
006 * %%
007 * Copyright (C) 2014 - 2023 Smile CDR, Inc.
008 * %%
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *      http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 * #L%
021 */
022
023import org.hl7.fhir.instance.model.api.IBaseResource;
024
025import javax.annotation.Nullable;
026
027/**
028 * This is used by "message" type subscriptions to provide a key to the message wrapper before submitting it to the channel
029 */
030public interface ISubscriptionMessageKeySvc {
031        /**
032         *  Given an {@link IBaseResource}, return a key that can be used to identify the message. This key will be used to
033         *  partition the message into a queue.
034         *
035         * @param thePayloadResource the payload resource.
036         * @return the key or null.
037         */
038        @Nullable
039        String getMessageKeyOrNull(IBaseResource thePayloadResource);
040}