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.ecm.platform.importer.mqueues.computation;
021
022/**
023 * @since 9.2
024 */
025public interface ComputationContext {
026
027    /**
028     * Set local state for a given key.
029     *
030     * @param key Key to set in local store.
031     * @param binaryValue Value to store at key.
032     */
033    void setState(final String key, final byte[] binaryValue);
034
035    /**
036     * Get local state for a given key
037     *
038     * @param key Key to receive from local store.
039     * @return the state executed upon data retrieval.
040     */
041    byte[] getState(final String key);
042
043    /**
044     * Register a timer callback for some point in the future
045     *
046     * @param key Name of the timer callback.
047     * @param time  The (ms since epoch) at which the callback should be fired
048     */
049    void setTimer(final String key, final long time);
050
051    /**
052     * Emit a record downstream. Records are send effectively on checkpoint using {@link #askForCheckpoint()}.
053     *
054     * @param streamName The name of the stream on which the record should be emitted.
055     * @param key The key associated with the record. Only relevant when routing method is `GROUP_BY`.
056     * @param data: The binary blob to send downstream.
057     */
058    void produceRecord(final String streamName, final String key, final byte[] data);
059
060    void produceRecord(final String streamName, final Record record);
061
062    /**
063     * Set the low watermark for a source computation.
064     */
065    void setSourceLowWatermark(long watermark);
066
067    /**
068     * Ask for checkpoint in order to send records, save input stream offset positions.
069     */
070    void askForCheckpoint();
071}