/**
* 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.IOException;
import java.util.ArrayList;
import javaewah.EWAHCompressedBitmap;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentTypeException;
import org.apache.hadoop.hive.ql.index.bitmap.BitmapObjectInput;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector.Category;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.BooleanObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils;
import org.apache.hadoop.io.BooleanWritable;
import org.apache.hadoop.io.LongWritable;
@Description(name = "ewah_bitmap_empty", value = "_FUNC_(bitmap) - "
+ "Predicate that tests whether an EWAH-compressed bitmap is all zeros ")
public class GenericUDFEWAHBitmapEmpty extends GenericUDF {
ObjectInspector bitmapOI;
BooleanObjectInspector boolOI;
@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length != 1) {
throw new UDFArgumentLengthException(
"The function EWAH_BITMAP_EMPTY(b) takes exactly 1 argument");
}
if (arguments[0].getCategory().equals(Category.LIST)) {
bitmapOI = (ListObjectInspector) arguments[0];
} else {
throw new UDFArgumentTypeException(0, "\""
+ Category.LIST.toString().toLowerCase()
+ "\" is expected at function EWAH_BITMAP_EMPTY, but \""
+ arguments[0].getTypeName() + "\" is found");
}
boolOI = PrimitiveObjectInspectorFactory.writableBooleanObjectInspector;
return boolOI;
}
@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
assert (arguments.length == 1);
Object b = arguments[0].get();
ListObjectInspector lloi = (ListObjectInspector) bitmapOI;
int length = lloi.getListLength(b);
ArrayList<LongWritable> bitmapArray = new ArrayList<LongWritable>();
for (int i = 0; i < length; i++) {
long l = PrimitiveObjectInspectorUtils.getLong(
lloi.getListElement(b, i),
(PrimitiveObjectInspector) lloi.getListElementObjectInspector());
bitmapArray.add(new LongWritable(l));
}
BitmapObjectInput bitmapObjIn = new BitmapObjectInput(bitmapArray);
EWAHCompressedBitmap bitmap = new EWAHCompressedBitmap();
try {
bitmap.readExternal(bitmapObjIn);
} catch (IOException e) {
throw new RuntimeException(e);
}
// Add return true only if bitmap is all zeros.
return new BooleanWritable(!bitmap.iterator().hasNext());
}
@Override
public String getDisplayString(String[] children) {
StringBuilder sb = new StringBuilder();
sb.append("EWAH_BITMAP_EMPTY(");
for (int i = 0; i < children.length; i++) {
sb.append(children[i]);
if (i + 1 != children.length) {
sb.append(",");
}
}
sb.append(")");
return sb.toString();
}
}