mattyb149 commented on a change in pull request #3318: NiFi-5537 Add Cypher Bundle URL: https://github.com/apache/nifi/pull/3318#discussion_r265630837
########## File path: nifi-nar-bundles/nifi-graph-bundle/nifi-graph-processors/src/main/java/org/apache/nifi/processors/graph/ExecuteGraphQuery.java ########## @@ -0,0 +1,141 @@ +/* + * 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.nifi.processors.graph; + +import com.fasterxml.jackson.databind.ObjectMapper; +import org.apache.nifi.annotation.behavior.EventDriven; +import org.apache.nifi.annotation.behavior.InputRequirement; +import org.apache.nifi.annotation.behavior.SupportsBatching; +import org.apache.nifi.annotation.behavior.WritesAttribute; +import org.apache.nifi.annotation.behavior.WritesAttributes; +import org.apache.nifi.annotation.documentation.CapabilityDescription; +import org.apache.nifi.annotation.documentation.Tags; +import org.apache.nifi.annotation.lifecycle.OnScheduled; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.graph.GraphClientService; +import org.apache.nifi.flowfile.FlowFile; +import org.apache.nifi.processor.ProcessContext; +import org.apache.nifi.processor.ProcessSession; +import org.apache.nifi.processor.Relationship; +import org.apache.nifi.processor.exception.ProcessException; + +import java.io.OutputStream; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Set; + +@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED) +@EventDriven +@SupportsBatching +@Tags({"cypher", "neo4j", "graph", "network", "insert", "update", "delete", "put", "get", + "node", "relationship", "connection", "executor", "gremlin", "tinkerpop"}) +@CapabilityDescription("This processor is designed to execute queries in either the Cypher query language or the Tinkerpop " + + "Gremlin DSL. It delegates most of the logic to a configured client service that handles the interaction with the " + + "remote data source.") +@WritesAttributes({ + @WritesAttribute(attribute = AbstractGraphExecutor.ERROR_MESSAGE, description = "GraphDB error message"), + @WritesAttribute(attribute = GraphClientService.LABELS_ADDED, description = "Number of labels added"), + @WritesAttribute(attribute = GraphClientService.NODES_CREATED, description = "Number of nodes created"), + @WritesAttribute(attribute = GraphClientService.NODES_DELETED, description = "Number of nodes deleted"), + @WritesAttribute(attribute = GraphClientService.PROPERTIES_SET, description = "Number of properties set"), + @WritesAttribute(attribute = GraphClientService.RELATIONS_CREATED, description = "Number of relationships created"), + @WritesAttribute(attribute = GraphClientService.RELATIONS_DELETED, description = "Number of relationships deleted"), + @WritesAttribute(attribute = GraphClientService.ROWS_RETURNED, description = "Number of rows returned"), + }) +public class ExecuteGraphQuery extends AbstractGraphExecutor { + + private static final Set<Relationship> relationships; + private static final List<PropertyDescriptor> propertyDescriptors; + + static { + final Set<Relationship> tempRelationships = new HashSet<>(); + tempRelationships.add(REL_SUCCESS); + tempRelationships.add(REL_FAILURE); + relationships = Collections.unmodifiableSet(tempRelationships); + + final List<PropertyDescriptor> tempDescriptors = new ArrayList<>(); + tempDescriptors.add(CLIENT_SERVICE); + tempDescriptors.add(QUERY); + + propertyDescriptors = Collections.unmodifiableList(tempDescriptors); + } + + protected ObjectMapper mapper = new ObjectMapper(); + + @Override + public Set<Relationship> getRelationships() { + return relationships; + } + + @Override + public final List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return propertyDescriptors; + } + + private volatile GraphClientService clientService; + + @OnScheduled + public void onScheduled(final ProcessContext context) { + super.onScheduled(context); + clientService = context.getProperty(CLIENT_SERVICE).asControllerService(GraphClientService.class); + } + + @Override + public void onTrigger(final ProcessContext context, final ProcessSession session) throws ProcessException { + FlowFile flowFile = session.get(); + if (flowFile == null) { + return; + } + + String query = context.getProperty(QUERY).evaluateAttributeExpressions(flowFile).getValue(); + + try (OutputStream os = session.write(flowFile)) { + long startTimeMillis = System.currentTimeMillis(); + + os.write("[".getBytes()); + Map<String, String> resultAttrs = clientService.executeQuery(query, getParameters(context, flowFile), (record, hasMore) -> { + try { + String obj = mapper.writeValueAsString(record); + os.write(obj.getBytes()); + if (hasMore) { + os.write(",".getBytes()); + } + } catch (Exception ex) { + throw new ProcessException(ex); + } + }); + os.write("]".getBytes()); + os.close(); + + final long endTimeMillis = System.currentTimeMillis(); + + flowFile = session.putAllAttributes(flowFile, resultAttrs); + + session.transfer(flowFile, REL_SUCCESS); + session.getProvenanceReporter().send(flowFile, clientService.getTransitUrl(), (endTimeMillis - startTimeMillis)); Review comment: Wondering if we should emit more than one provenance event here, based perhaps on the metrics we get back from executing the query. For example, a `MATCH(p) RETURN p` is not really a `SEND` event, and even one that does "send" data like a `CREATE`/`MERGE`, if we are overwriting the flow file with the returned contents, then it probably should emit a `FETCH` event. There's also `REMOTE_INVOCATION` but that might be more confusing than helpful (since it is meant for remote operations that do neither fetch nor send, whereas our queries could do one or both). Thoughts? ---------------------------------------------------------------- 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
