001/**
002 * Copyright (C) 2006-2022 Talend Inc. - www.talend.com
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 */
016package org.talend.sdk.component.api.input;
017
018import static java.lang.annotation.ElementType.TYPE;
019import static java.lang.annotation.RetentionPolicy.RUNTIME;
020
021import java.lang.annotation.Retention;
022import java.lang.annotation.Target;
023
024@Target(TYPE)
025@Retention(RUNTIME)
026public @interface PartitionMapper {
027
028    /**
029     * @return the component of this mapper (family/grouping value).
030     */
031    String family() default "";
032
033    /**
034     * @return the value of the related input.
035     */
036    String name() default "";
037
038    /**
039     * If the @Producer method of the underlying {@link Emitter} can return null before the data
040     * are completely read - i.e. infinite flow case - then you should set true to prevent the
041     * execution to complete when null is encountered.
042     *
043     * Default cases matches a batch case whereas when set to true it matches a stream case.
044     *
045     * @return true if the underlying input can be used as a stream and not in batch context.
046     */
047    boolean infinite() default false;
048
049    /**
050     * Allow to provide an UI to customize a set of conditions to stop the infinite loop.
051     * Only valid when {@code infinite()} returns true. So affects only streaming PartitionMappers.
052     *
053     * Caution:
054     * Some records may be lost according the connector's Emitter implementation.
055     * For instance, suppose that the connector maintains a queue with a size of 10 records, and we have in the stop
056     * strategy a max records set to 5. If the first 10 records are considered as acknowledged, then the 5 first records
057     * will be read but the 5 next will be considered lost.
058     *
059     * @return true if the underlying input can customize a stop strategy.
060     */
061    boolean stoppable() default false;
062}