/*
* 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 hivemall.ensemble;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.udf.UDFType;
import org.apache.hadoop.hive.ql.udf.generic.AbstractGenericUDAFResolver;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator;
import org.apache.hadoop.hive.serde2.lazybinary.LazyBinaryStruct;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils;
import org.apache.hadoop.hive.serde2.objectinspector.StructField;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoUtils;
@Description(
name = "maxrow",
value = "_FUNC_(ANY compare, ...) - Returns a row that has maximum value in the 1st argument")
public final class MaxRowUDAF extends AbstractGenericUDAFResolver {
@Override
public GenericUDAFEvaluator getEvaluator(TypeInfo[] parameters) throws SemanticException {
ObjectInspector oi = TypeInfoUtils.getStandardJavaObjectInspectorFromTypeInfo(parameters[0]);
if (!ObjectInspectorUtils.compareSupported(oi)) {
throw new UDFArgumentTypeException(0,
"Cannot support comparison of map<> type or complex type containing map<>.");
}
return new GenericUDAFMaxRowEvaluator();
}
@UDFType(distinctLike = true)
public static class GenericUDAFMaxRowEvaluator extends GenericUDAFEvaluator {
StructObjectInspector inputStructOI;
ObjectInspector[] inputOIs;
ObjectInspector[] outputOIs;
@Override
public ObjectInspector init(Mode mode, ObjectInspector[] parameters) throws HiveException {
super.init(mode, parameters);
if (parameters.length == 1 && parameters[0] instanceof StructObjectInspector) {
return initReduceSide((StructObjectInspector) parameters[0]);
} else {
return initMapSide(parameters);
}
}
private ObjectInspector initMapSide(ObjectInspector[] parameters) throws HiveException {
int length = parameters.length;
this.inputOIs = parameters;
this.outputOIs = new ObjectInspector[length];
List<String> fieldNames = new ArrayList<String>(length);
List<ObjectInspector> fieldOIs = Arrays.asList(outputOIs);
for (int i = 0; i < length; i++) {
fieldNames.add("col" + i);
outputOIs[i] = ObjectInspectorUtils.getStandardObjectInspector(parameters[i]);
}
return ObjectInspectorFactory.getStandardStructObjectInspector(fieldNames, fieldOIs);
}
private ObjectInspector initReduceSide(StructObjectInspector inputStructOI)
throws HiveException {
List<? extends StructField> fields = inputStructOI.getAllStructFieldRefs();
int length = fields.size();
this.inputStructOI = inputStructOI;
this.inputOIs = new ObjectInspector[length];
this.outputOIs = new ObjectInspector[length];
for (int i = 0; i < length; i++) {
StructField field = fields.get(i);
ObjectInspector oi = field.getFieldObjectInspector();
inputOIs[i] = oi;
outputOIs[i] = ObjectInspectorUtils.getStandardObjectInspector(oi);
}
return ObjectInspectorUtils.getStandardObjectInspector(inputStructOI);
}
static class MaxAgg extends AbstractAggregationBuffer {
Object[] objects;
MaxAgg() {
super();
}
void reset() {
this.objects = null;
}
}
@Override
public MaxAgg getNewAggregationBuffer() throws HiveException {
MaxAgg maxagg = new MaxAgg();
maxagg.reset();
return maxagg;
}
@Override
public void reset(@SuppressWarnings("deprecation") AggregationBuffer agg)
throws HiveException {
MaxAgg maxagg = (MaxAgg) agg;
maxagg.reset();
}
@Override
public void iterate(@SuppressWarnings("deprecation") AggregationBuffer agg,
Object[] parameters) throws HiveException {
merge(agg, parameters);
}
@Override
public List<Object> terminatePartial(@SuppressWarnings("deprecation") AggregationBuffer agg)
throws HiveException {
return terminate(agg);
}
@Override
public void merge(@SuppressWarnings("deprecation") AggregationBuffer agg, Object partial)
throws HiveException {
if (partial == null) {
return;
}
final MaxAgg maxagg = (MaxAgg) agg;
final List<Object> otherObjects;
if (partial instanceof Object[]) {
otherObjects = Arrays.asList((Object[]) partial);
} else if (partial instanceof LazyBinaryStruct) {
otherObjects = ((LazyBinaryStruct) partial).getFieldsAsList();
} else if (inputStructOI != null) {
otherObjects = inputStructOI.getStructFieldsDataAsList(partial);
} else {
throw new HiveException("Invalid type: " + partial.getClass().getName());
}
boolean isMax = false;
if (maxagg.objects == null) {
isMax = true;
} else {
int cmp = ObjectInspectorUtils.compare(maxagg.objects[0], outputOIs[0],
otherObjects.get(0), inputOIs[0]);
if (cmp < 0) {
isMax = true;
}
}
if (isMax) {
int length = otherObjects.size();
maxagg.objects = new Object[length];
for (int i = 0; i < length; i++) {
maxagg.objects[i] = ObjectInspectorUtils.copyToStandardObject(
otherObjects.get(i), inputOIs[i]);
}
}
}
@Override
public List<Object> terminate(@SuppressWarnings("deprecation") AggregationBuffer agg)
throws HiveException {
MaxAgg maxagg = (MaxAgg) agg;
return Arrays.asList(maxagg.objects);
}
}
}