org.apache.hadoop.hive.ql.exec.ExprNodeFuncEvaluator.java Source code

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Here is the source code for org.apache.hadoop.hive.ql.exec.ExprNodeFuncEvaluator.java

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/**
 * 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.hadoop.hive.ql.exec;

import java.lang.reflect.Method;
import java.util.Arrays;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.plan.exprNodeFuncDesc;
import org.apache.hadoop.hive.serde2.objectinspector.InspectableObject;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.util.ReflectionUtils;

public class ExprNodeFuncEvaluator extends ExprNodeEvaluator {

    private static final Log LOG = LogFactory.getLog(ExprNodeFuncEvaluator.class.getName());

    protected exprNodeFuncDesc expr;
    transient ExprNodeEvaluator[] paramEvaluators;
    transient InspectableObject[] paramInspectableObjects;
    transient Object[] paramValues;
    transient UDF udf;
    transient Method udfMethod;
    transient ObjectInspector outputObjectInspector;

    public ExprNodeFuncEvaluator(exprNodeFuncDesc expr) {
        this.expr = expr;
        assert (expr != null);
        Class<?> c = expr.getUDFClass();
        udfMethod = expr.getUDFMethod();
        LOG.debug(c.toString());
        LOG.debug(udfMethod.toString());
        udf = (UDF) ReflectionUtils.newInstance(expr.getUDFClass(), null);
        int paramNumber = expr.getChildren().size();
        paramEvaluators = new ExprNodeEvaluator[paramNumber];
        paramInspectableObjects = new InspectableObject[paramNumber];
        for (int i = 0; i < paramNumber; i++) {
            paramEvaluators[i] = ExprNodeEvaluatorFactory.get(expr.getChildren().get(i));
            paramInspectableObjects[i] = new InspectableObject();
        }
        paramValues = new Object[expr.getChildren().size()];
        outputObjectInspector = ObjectInspectorFactory
                .getStandardPrimitiveObjectInspector(udfMethod.getReturnType());
    }

    public void evaluate(Object row, ObjectInspector rowInspector, InspectableObject result) throws HiveException {
        if (result == null) {
            throw new HiveException("result cannot be null.");
        }
        // Evaluate all children first
        for (int i = 0; i < paramEvaluators.length; i++) {
            paramEvaluators[i].evaluate(row, rowInspector, paramInspectableObjects[i]);
            paramValues[i] = paramInspectableObjects[i].o;
        }
        try {
            result.o = udfMethod.invoke(udf, paramValues);
            result.oi = outputObjectInspector;
        } catch (Exception e) {
            if (e instanceof HiveException) {
                throw (HiveException) e;
            } else if (e instanceof RuntimeException) {
                throw (RuntimeException) e;
            } else {
                throw new HiveException(
                        "Unable to execute UDF function " + udf.getClass() + " " + udfMethod + " on inputs " + "("
                                + paramValues.length + ") " + Arrays.asList(paramValues) + ": " + e.getMessage(),
                        e);
            }
        }
    }

    public ObjectInspector evaluateInspector(ObjectInspector rowInspector) throws HiveException {
        return outputObjectInspector;
    }
}