| /* |
| * 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.tinkerpop.gremlin.process.traversal.util; |
| |
| import org.apache.tinkerpop.gremlin.jsr223.SingleGremlinScriptEngineManager; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraversalSource; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategy; |
| |
| import javax.script.Bindings; |
| import javax.script.ScriptEngine; |
| import javax.script.ScriptException; |
| import java.util.List; |
| |
| /** |
| * ScriptTraversal encapsulates a {@link ScriptEngine} and a script which is compiled into a {@link Traversal} at {@link Admin#applyStrategies()}. |
| * This is useful for serializing traversals as the compilation can happen on the remote end where the traversal will ultimately be processed. |
| * |
| * @author Marko A. Rodriguez (http://markorodriguez.com) |
| */ |
| public final class ScriptTraversal<S, E> extends DefaultTraversal<S, E> { |
| |
| private final String alias; |
| private final TraversalSourceFactory factory; |
| private final String script; |
| private final String scriptEngine; |
| private final Object[] bindings; |
| |
| public ScriptTraversal(final TraversalSource traversalSource, final String scriptEngine, final String script, final Object... bindings) { |
| super(); |
| this.alias = "g"; |
| this.graph = traversalSource.getGraph(); |
| this.factory = new TraversalSourceFactory<>(traversalSource); |
| this.scriptEngine = scriptEngine; |
| this.script = script; |
| this.bindings = bindings; |
| if (this.bindings.length % 2 != 0) |
| throw new IllegalArgumentException("The provided key/value bindings array length must be a multiple of two"); |
| } |
| |
| @Override |
| public void applyStrategies() throws IllegalStateException { |
| try { |
| assert 0 == this.getSteps().size(); |
| final ScriptEngine engine = SingleGremlinScriptEngineManager.get(this.scriptEngine); |
| final Bindings engineBindings = engine.createBindings(); |
| final List<TraversalStrategy<?>> strategyList = this.getStrategies().toList(); |
| engineBindings.put(this.alias, this.factory.createTraversalSource(this.graph).withStrategies(strategyList.toArray(new TraversalStrategy[strategyList.size()]))); |
| engineBindings.put("graph", this.graph); // TODO: we don't need this as the traversalSource.getGraph() exists, but its now here and people might be using it (remove in 3.3.0) |
| for (int i = 0; i < this.bindings.length; i = i + 2) { |
| engineBindings.put((String) this.bindings[i], this.bindings[i + 1]); |
| } |
| final Traversal.Admin<S, E> traversal = (Traversal.Admin<S, E>) engine.eval(this.script, engineBindings); |
| traversal.getSideEffects().mergeInto(this.sideEffects); |
| traversal.getSteps().forEach(this::addStep); |
| this.strategies = traversal.getStrategies(); |
| super.applyStrategies(); |
| } catch (final ScriptException e) { |
| throw new IllegalStateException(e.getMessage(), e); |
| } |
| } |
| } |