dongjoon-hyun commented on a change in pull request #24851: [SPARK-27303][GRAPH] Add Spark Graph API URL: https://github.com/apache/spark/pull/24851#discussion_r331764101
########## File path: graph/api/src/main/scala/org/apache/spark/graph/api/GraphElementFrame.scala ########## @@ -0,0 +1,260 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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.apache.spark.graph.api + +import scala.collection.JavaConverters._ + +import org.apache.spark.sql.DataFrame + +/** + * A [[PropertyGraph]] is created from GraphElementFrames. + * + * A graph element is either a node or a relationship. + * A GraphElementFrame wraps a DataFrame and describes how it maps to graph elements. + * + * @since 3.0.0 + */ +abstract class GraphElementFrame { + + /** + * Initial DataFrame that can still contain unmapped, arbitrarily ordered columns. + * + * @since 3.0.0 + */ + def df: DataFrame + + /** + * Name of the column that contains the graph element identifier. + * + * @since 3.0.0 + */ + def idColumn: String + + /** + * Name of all columns that contain graph element identifiers. + * + * @since 3.0.0 + */ + def idColumns: Seq[String] = Seq(idColumn) + + /** + * Mapping from graph element property keys to the columns that contain the corresponding property + * values. + * + * @since 3.0.0 + */ + def properties: Map[String, String] + +} + +object NodeFrame { + + /** + * Describes how to map an initial DataFrame to nodes. + * + * All columns apart from the given `idColumn` are mapped to node properties. + * + * @param df DataFrame containing a single node in each row + * @param idColumn column that contains the node identifier + * @param labelSet labels that are assigned to all nodes + * @since 3.0.0 + */ + def create(df: DataFrame, idColumn: String, labelSet: Set[String]): NodeFrame = { + val properties = (df.columns.toSet - idColumn) + .map(columnName => columnName -> columnName) + .toMap + create(df, idColumn, labelSet, properties) + } + + /** + * Describes how to map an initial DataFrame to nodes. + * + * All columns apart from the given `idColumn` are mapped to node properties. + * + * @param df DataFrame containing a single node in each row + * @param idColumn column that contains the node identifier + * @param labelSet labels that are assigned to all nodes + * @param properties mapping from property keys to corresponding columns + * @since 3.0.0 + */ + def create( + df: DataFrame, + idColumn: String, + labelSet: Set[String], + properties: Map[String, String]): NodeFrame = { + NodeFrame(df, idColumn, labelSet, properties) + } + + /** + * Describes how to map an initial DataFrame to nodes. + * + * All columns apart from the given `idColumn` are mapped to node properties. + * + * @param df DataFrame containing a single node in each row + * @param idColumn column that contains the node identifier + * @param labelSet labels that are assigned to all nodes + * @since 3.0.0 + */ + def create(df: DataFrame, idColumn: String, labelSet: java.util.Set[String]): NodeFrame = { + create(df, idColumn, labelSet.asScala.toSet) + } + + /** + * Describes how to map an initial DataFrame to nodes. + * + * All columns apart from the given `idColumn` are mapped to node properties. + * + * @param df DataFrame containing a single node in each row + * @param idColumn column that contains the node identifier + * @param labelSet labels that are assigned to all nodes + * @param properties mapping from property keys to corresponding columns + * @since 3.0.0 + */ + def create( Review comment: Yep. Please follow @mengxr 's advice. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
