JythonSimpleFunction.java

/**
 * 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.drill.exec.scripting.jython;

import org.apache.drill.exec.expr.DrillSimpleFunc;
import org.apache.drill.exec.record.RecordBatch;
import org.python.core.PyInstance;
import org.python.util.PythonInterpreter;

public class JythonSimpleFunction implements DrillSimpleFunc {
    PythonInterpreter interpreter;
    String scriptPath;
    String funcName;
    PyInstance instance;

    public JythonSimpleFunction(String scriptPath, String funcName){
        this.scriptPath = scriptPath;
        this.funcName = funcName;

        PythonInterpreter.initialize(System.getProperties(), System.getProperties(), new String[0]);
        this.interpreter = new PythonInterpreter();

        this.execfile(scriptPath);
        instance = this.createClass(funcName, "None");
    }

    private void execfile(final String fileName) {
        this.interpreter.execfile(fileName);
    }

    private PyInstance createClass( final String className, final String opts ) {
        return (PyInstance) this.interpreter.eval(className + "(" + opts + ")");
    }

    @Override
    public void setup(RecordBatch incoming) {
        instance.invoke("setup");
    }

    @Override
    public void eval() {
        instance.invoke("eval");
    }
}