/**
* 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.udf.generic;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.hive.ql.exec.ExprNodeEvaluator;
import org.apache.hadoop.hive.ql.exec.ExprNodeEvaluatorFactory;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoUtils;
/**
* GenericUDFMacro wraps a user-defined macro expression into a GenericUDF
* interface.
*/
public class GenericUDFMacro extends GenericUDF implements Serializable {
private static final long serialVersionUID = 2829755821687181020L;
private String macroName;
private ExprNodeDesc bodyDesc;
private transient ExprNodeEvaluator body;
private List<String> colNames;
private List<TypeInfo> colTypes;
private transient ObjectInspectorConverters.Converter converters[];
private transient ArrayList<Object> evaluatedArguments;
public GenericUDFMacro(String macroName, ExprNodeDesc bodyDesc,
List<String> colNames, List<TypeInfo> colTypes) {
this.macroName = macroName;
this.bodyDesc = bodyDesc;
this.colNames = colNames;
this.colTypes = colTypes;
assert(this.bodyDesc != null);
assert(colNames.size() == colTypes.size());
}
// For serialization only.
public GenericUDFMacro() {
}
public boolean isDeterministic() {
if(body != null) {
return body.isDeterministic();
}
return true;
}
public boolean isStateful() {
if(body != null) {
return body.isStateful();
}
return false;
}
private void checkNotNull(Object object, String msg) {
if(object == null) {
throw new NullPointerException(msg);
}
}
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
checkNotNull(colTypes, "colTypes");
checkNotNull(arguments, "arguments");
checkNotNull(bodyDesc, "bodyDesc");
if(colTypes.size() != arguments.length) {
throw new UDFArgumentLengthException(
"The macro " + macroName + " accepts exactly " + colTypes.size() + " arguments.");
}
try {
body = ExprNodeEvaluatorFactory.get(bodyDesc);
} catch (HiveException ex) {
throw new UDFArgumentException(ex);
}
converters = new ObjectInspectorConverters.Converter[arguments.length];
ArrayList<ObjectInspector> colObjectInspectors = new ArrayList<ObjectInspector>(colTypes.size());
for (int index = 0; index < arguments.length; ++index) {
ObjectInspector objectInspector = TypeInfoUtils.
getStandardWritableObjectInspectorFromTypeInfo(colTypes.get(index));
colObjectInspectors.add(objectInspector);
converters[index] =
ObjectInspectorConverters.getConverter(arguments[index], objectInspector);
}
evaluatedArguments = new ArrayList<Object>(arguments.length);
ObjectInspector structOI = ObjectInspectorFactory
.getStandardStructObjectInspector(colNames, colObjectInspectors);
try {
return body.initialize(structOI);
} catch (HiveException ex) {
throw new UDFArgumentException(ex);
}
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
evaluatedArguments.clear();
for (int index = 0; index < arguments.length; ++index) {
evaluatedArguments.add(converters[index].convert(arguments[index].get()));
}
return body.evaluate(evaluatedArguments);
}
@Override
public String getDisplayString(String[] children) {
StringBuilder sb = new StringBuilder();
sb.append(macroName);
sb.append("(");
for (int i = 0; i < children.length; i++) {
sb.append(children[i]);
if (i + 1 < children.length) {
sb.append(", ");
}
}
sb.append(")");
return sb.toString();
}
public void setMacroName(String macroName) {
this.macroName = macroName;
}
public String getMacroName() {
return macroName;
}
public void setBody(ExprNodeDesc bodyDesc) {
this.bodyDesc = bodyDesc;
}
public ExprNodeDesc getBody() {
return bodyDesc;
}
public void setColNames(List<String> colNames) {
this.colNames = colNames;
}
public List<String> getColNames() {
return colNames;
}
public void setColTypes(List<TypeInfo> colTypes) {
this.colTypes = colTypes;
}
public List<TypeInfo> getColTypes() {
return colTypes;
}
}