s1ck commented on a change in pull request #24851: [SPARK-27303][GRAPH] Add Spark Graph API URL: https://github.com/apache/spark/pull/24851#discussion_r307612780
########## 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( + df: DataFrame, + idColumn: String, + labelSet: java.util.Set[String], + properties: java.util.Map[String, String]): NodeFrame = { + val scalaLabelSet = labelSet.asScala.toSet + val scalaProperties = properties.asScala.toMap + NodeFrame(df, idColumn, scalaLabelSet, scalaProperties) + } + +} + +/** + * Describes how to map a DataFrame to nodes. + * + * Each row in the DataFrame represents a node which has exactly the labels defined by the given + * label set. + * + * @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 + */ +case class NodeFrame private[graph] ( + df: DataFrame, + idColumn: String, + labelSet: Set[String], + properties: Map[String, String]) + extends GraphElementFrame + +object RelationshipFrame { + + /** + * Describes how to map a DataFrame to relationships. + * + * All columns apart from the given identifier columns are mapped to relationship properties. + * + * @param df DataFrame containing a single relationship in each row + * @param idColumn column that contains the relationship identifier + * @param sourceIdColumn column that contains the source node identifier of the relationship + * @param targetIdColumn column that contains the target node identifier of the relationship + * @param relationshipType relationship type that is assigned to all relationships + * @since 3.0.0 + */ + def create( + df: DataFrame, + idColumn: String, + sourceIdColumn: String, + targetIdColumn: String, + relationshipType: String): RelationshipFrame = { + val properties = (df.columns.toSet - idColumn - sourceIdColumn - targetIdColumn) + .map(columnName => columnName -> columnName) + .toMap + + create(df, idColumn, sourceIdColumn, targetIdColumn, relationshipType, properties) + } + + /** + * Describes how to map a DataFrame to relationships. + * + * @param df DataFrame containing a single relationship in each row + * @param idColumn column that contains the relationship identifier + * @param sourceIdColumn column that contains the source node identifier of the relationship + * @param targetIdColumn column that contains the target node identifier of the relationship + * @param relationshipType relationship type that is assigned to all relationships + * @param properties mapping from property keys to corresponding columns + * @since 3.0.0 + */ + def create( + df: DataFrame, + idColumn: String, + sourceIdColumn: String, + targetIdColumn: String, + relationshipType: String, + properties: Map[String, String]): RelationshipFrame = { + RelationshipFrame(df, idColumn, sourceIdColumn, targetIdColumn, relationshipType, properties) + } + + /** + * Describes how to map a DataFrame to relationships. + * + * @param df DataFrame containing a single relationship in each row + * @param idColumn column that contains the relationship identifier + * @param sourceIdColumn column that contains the source node identifier of the relationship + * @param targetIdColumn column that contains the target node identifier of the relationship + * @param relationshipType relationship type that is assigned to all relationships + * @param properties mapping from property keys to corresponding columns + * @since 3.0.0 + */ + def create( Review comment: See above ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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