InitElement.java
- /*
- * Copyright © 2014 - 2021 Leipzig University (Database Research Group)
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- package org.gradoop.flink.io.impl.graph.functions;
- import org.apache.flink.api.common.typeinfo.TypeInformation;
- import org.gradoop.common.model.impl.pojo.EPGMElement;
- import java.io.Serializable;
- import static com.google.common.base.Preconditions.checkNotNull;
- /**
- * Abstract base class for initializing EPGM elements from import elements.
- *
- * @param <EL> EPGM element type
- * @param <K> Import EPGMEdge/EPGMVertex identifier type
- */
- public abstract class InitElement
- <EL extends EPGMElement, K extends Comparable<K>> implements Serializable {
- /**
- * Decides if lineage info (original identifier) shall be stored
- */
- private final boolean keepLineage;
- /**
- * Used to store the lineage information at the resulting EPGM element
- */
- private final String lineagePropertyKey;
- /**
- * Type information for the import element identifier
- */
- private final TypeInformation<K> keyTypeInfo;
- /**
- * Constructor.
- *
- * If the given property key is {@code null}, no lineage info will be stored.
- *
- * @param lineagePropertyKey property key to store lineage info at EPGM
- * element (can be {@code null})
- * @param keyTypeInfo type info for import element identifier
- */
- public InitElement(String lineagePropertyKey,
- TypeInformation<K> keyTypeInfo) {
- this.keepLineage = lineagePropertyKey != null;
- this.lineagePropertyKey = lineagePropertyKey;
- this.keyTypeInfo = checkNotNull(keyTypeInfo, "key type was null");
- }
- /**
- * Updates the lineage info of the given EPGM element if necessary.
- *
- * @param element EPGM element
- * @param importKey import element identifier
- * @return updated EPGM element
- */
- protected EL updateLineage(EL element, K importKey) {
- if (keepLineage) {
- element.setProperty(lineagePropertyKey, importKey);
- }
- return element;
- }
- /**
- * Returns type information for the import element identifier.
- *
- * @return import element identifier type info
- */
- protected TypeInformation<K> getKeyTypeInfo() {
- return keyTypeInfo;
- }
- }