mattyb149 commented on a change in pull request #4204: NIFI-7355 Added Gremlin bytecode client service. URL: https://github.com/apache/nifi/pull/4204#discussion_r409678391
########## File path: nifi-nar-bundles/nifi-graph-bundle/nifi-other-graph-services/src/main/java/org/apache/nifi/graph/GremlinBytecodeClientService.java ########## @@ -0,0 +1,168 @@ +/* + * 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.graph; + + +import org.apache.commons.codec.digest.DigestUtils; +import org.apache.nifi.annotation.documentation.CapabilityDescription; +import org.apache.nifi.annotation.documentation.Tags; +import org.apache.nifi.annotation.lifecycle.OnDisabled; +import org.apache.nifi.annotation.lifecycle.OnEnabled; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.components.Validator; +import org.apache.nifi.controller.ConfigurationContext; +import org.apache.nifi.expression.ExpressionLanguageScope; +import org.apache.nifi.processor.exception.ProcessException; +import org.apache.nifi.reporting.InitializationException; +import org.apache.nifi.util.StringUtils; +import org.apache.tinkerpop.gremlin.driver.Cluster; +import org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteConnection; +import org.apache.tinkerpop.gremlin.process.traversal.AnonymousTraversalSource; +import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource; + +import javax.script.Bindings; +import javax.script.Compilable; +import javax.script.CompiledScript; +import javax.script.ScriptEngine; +import javax.script.ScriptEngineManager; +import javax.script.ScriptException; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.concurrent.ConcurrentHashMap; + +@CapabilityDescription("A client service that provides a scriptable interface to open a remote connection/travseral " + + "against a Gremlin Server and execute operations against it.") +@Tags({ "graph", "database", "gremlin", "tinkerpop" }) +public class GremlinBytecodeClientService extends AbstractTinkerpopClientService implements GraphClientService { + private static final List<PropertyDescriptor> NEW_DESCRIPTORS; + + public static final PropertyDescriptor TRAVERSAL_SOURCE_NAME = new PropertyDescriptor.Builder() + .name("gremlin-traversal-source-name") + .displayName("Traversal Source Name") + .description("An optional property that lets you set the name of the remote traversal instance. " + + "This can be really important when working with databases like JanusGraph that support " + + "multiple backend traversal configurations simultaneously.") + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .addValidator(Validator.VALID) + .build(); + + static { + List<PropertyDescriptor> _temp = new ArrayList<>(); + _temp.addAll(DESCRIPTORS); + _temp.add(TRAVERSAL_SOURCE_NAME); + NEW_DESCRIPTORS = Collections.unmodifiableList(_temp); + } + + + @Override + public List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return NEW_DESCRIPTORS; + } + + private ScriptEngineManager MANAGER = new ScriptEngineManager(); + private ScriptEngine engine; + private Map<String, CompiledScript> compiledCode; + private Cluster cluster; + private String traversalSourceName; + + /** + * @param context + * the configuration context + * @throws InitializationException + * if unable to create a database connection + */ + @OnEnabled + public void onEnabled(final ConfigurationContext context) throws InitializationException { + cluster = buildCluster(context); + + compiledCode = new ConcurrentHashMap<>(); + engine = MANAGER.getEngineByName("groovy"); + + if (context.getProperty(TRAVERSAL_SOURCE_NAME).isSet()) { + traversalSourceName = context.getProperty(TRAVERSAL_SOURCE_NAME).evaluateAttributeExpressions() + .getValue(); + } + } + + @OnDisabled + public void shutdown() { + try { + compiledCode = null; + engine = null; + cluster.close(); + } catch (Exception e) { + throw new ProcessException(e); + } + } + + @Override + public Map<String, String> executeQuery(String s, Map<String, Object> map, GraphQueryResultCallback graphQueryResultCallback) { + String hash = DigestUtils.md5Hex(s); + CompiledScript compiled; + GraphTraversalSource traversal; + + try { + if (StringUtils.isEmpty(traversalSourceName)) { + traversal = AnonymousTraversalSource.traversal().withRemote(DriverRemoteConnection.using(cluster)); + } else { + traversal = AnonymousTraversalSource.traversal().withRemote(DriverRemoteConnection.using(cluster, traversalSourceName)); + } + } catch (Exception e) { + throw new ProcessException(e); + } + + if (compiledCode.containsKey(hash)) { + compiled = compiledCode.get(hash); + } else { + try { + compiled = ((Compilable)engine).compile(s); + compiledCode.put(s, compiled); + } catch (ScriptException e) { + throw new ProcessException(e); + } + } + + Bindings bindings = engine.createBindings(); + bindings.putAll(map); + bindings.put("g", traversal); Review comment: Should probably mention this variable in the documentation somewhere if its intent is to be available to user scripts. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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