/*
* 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.python.jsr223;
import org.apache.tinkerpop.gremlin.jsr223.JavaTranslator;
import org.apache.tinkerpop.gremlin.jsr223.ScriptEngineCache;
import org.apache.tinkerpop.gremlin.process.traversal.Bytecode;
import org.apache.tinkerpop.gremlin.process.traversal.Translator;
import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
import org.apache.tinkerpop.gremlin.process.traversal.TraversalSource;
import org.apache.tinkerpop.gremlin.process.traversal.util.BytecodeHelper;
import org.apache.tinkerpop.gremlin.structure.io.graphson.GraphSONMapper;
import org.apache.tinkerpop.gremlin.structure.io.graphson.GraphSONReader;
import org.apache.tinkerpop.gremlin.structure.io.graphson.GraphSONVersion;
import org.apache.tinkerpop.gremlin.structure.io.graphson.GraphSONWriter;
import org.apache.tinkerpop.gremlin.structure.io.graphson.GraphSONXModuleV2d0;
import org.apache.tinkerpop.shaded.jackson.core.JsonFactory;
import org.apache.tinkerpop.shaded.jackson.databind.ObjectMapper;
import javax.script.Bindings;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Map;
import static org.junit.Assert.assertEquals;
/**
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
final class PythonGraphSONJavaTranslator<S extends TraversalSource, T extends Traversal.Admin<?, ?>> implements Translator.StepTranslator<S, T> {
private final boolean IS_TESTING = Boolean.valueOf(System.getProperty("is.testing", "false"));
private final PythonTranslator pythonTranslator;
private final JavaTranslator<S, T> javaTranslator;
private final GraphSONReader reader = GraphSONReader.build().mapper(
GraphSONMapper.build().addCustomModule(GraphSONXModuleV2d0.build().create(false))
.version(GraphSONVersion.V3_0).create()).create();
private final GraphSONWriter writer = GraphSONWriter.build().mapper(
GraphSONMapper.build().addCustomModule(GraphSONXModuleV2d0.build().create(false))
.version(GraphSONVersion.V3_0).create()).create();
public PythonGraphSONJavaTranslator(final PythonTranslator pythonTranslator, final JavaTranslator<S, T> javaTranslator) {
this.pythonTranslator = pythonTranslator;
this.javaTranslator = javaTranslator;
}
@Override
public S getTraversalSource() {
return this.javaTranslator.getTraversalSource();
}
@Override
public String getTargetLanguage() {
return this.javaTranslator.getTargetLanguage();
}
@Override
public T translate(final Bytecode bytecode) {
try {
final ScriptEngine jythonEngine = ScriptEngineCache.get("jython");
final Bindings bindings = jythonEngine.createBindings();
bindings.putAll(jythonEngine.getBindings(ScriptContext.ENGINE_SCOPE));
bindings.put(this.pythonTranslator.getTraversalSource(), jythonEngine.eval("Graph().traversal()"));
bindings.putAll(bytecode.getBindings());
final String translatedGraphSONBytecode = jythonEngine.eval("graphson_writer.writeObject(" + this.pythonTranslator.translate(bytecode) + ")", bindings).toString();
if (IS_TESTING) {
// verify that the GraphSON sent to Python is the same as the GraphSON returned by Python
final ByteArrayOutputStream output = new ByteArrayOutputStream();
BytecodeHelper.removeBindings(bytecode); // this is because bindings are variables that get converted to values at translation
BytecodeHelper.detachElements(bytecode); // this is to get the minimal necessary representation
this.writer.writeObject(output, bytecode);
final String originalGraphSONBytecode = new String(output.toByteArray());
final ObjectMapper mapper = new ObjectMapper(new JsonFactory());
final Map<String, Object> original = mapper.readValue(originalGraphSONBytecode, Map.class);
final Map<String, Object> translated = mapper.readValue(translatedGraphSONBytecode, Map.class);
assertEquals(originalGraphSONBytecode.length(), translatedGraphSONBytecode.length());
assertEquals(original, translated);
}
return this.javaTranslator.translate(this.reader.readObject(new ByteArrayInputStream(translatedGraphSONBytecode.getBytes()), Bytecode.class));
} catch (final Exception e) {
throw new IllegalArgumentException(e.getMessage(), e);
}
}
}