001/*
002 * (C) Copyright 2017 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Adapted from from https://github.com/concord/concord-jvm
018 *     bdelbosc
019 */
020package org.nuxeo.lib.stream.computation;
021
022/**
023 * @since 9.3
024 */
025public interface ComputationContext {
026
027    /**
028     * Register a timer callback for some point in the future
029     *
030     * @param key Name of the timer callback.
031     * @param time The (ms since epoch) at which the callback should be fired
032     */
033    void setTimer(String key, long time);
034
035    /**
036     * Emit a record downstream. Records are send effectively on checkpoint using {@link #askForCheckpoint()}.
037     *
038     * @param streamName The name of the stream on which the record should be emitted.
039     * @param key The key associated with the record. Only relevant when routing method is `GROUP_BY`.
040     * @param data: The binary blob to send downstream.
041     */
042    default void produceRecord(String streamName, String key, byte[] data) {
043        produceRecord(streamName, Record.of(key, data));
044    }
045
046    void produceRecord(String streamName, Record record);
047
048    /**
049     * Set the low watermark for a source computation.
050     */
051    void setSourceLowWatermark(long watermark);
052
053    /**
054     * Ask for checkpoint in order to send records, save input stream offset positions.
055     */
056    void askForCheckpoint();
057}