com.yahoo.sketches.hive.tuple.ArrayOfDoublesSketchToNumberOfRetainedEntriesUDF Maven / Gradle / Ivy
/*
* Copyright 2017, Yahoo! Inc.
* Licensed under the terms of the Apache License 2.0. See LICENSE file at the project root for terms.
*/
package com.yahoo.sketches.hive.tuple;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.BytesWritable;
import com.yahoo.memory.Memory;
import com.yahoo.sketches.tuple.ArrayOfDoublesSketch;
import com.yahoo.sketches.tuple.ArrayOfDoublesSketches;
@Description(
name = "ArrayOfDoublesSketchToNumberOfRetainedEntries",
value = "_FUNC_(sketch)",
extended = "Returns the number of retained entries from a given ArrayOfDoublesSketch."
+ " The result is an integer value.")
public class ArrayOfDoublesSketchToNumberOfRetainedEntriesUDF extends UDF {
/**
* Get number of retained entries from a given ArrayOfDoublesSketch
* @param serializedSketch ArrayOfDoublesSketch in as serialized binary
* @return number of retained entries
*/
public Integer evaluate(final BytesWritable serializedSketch) {
if (serializedSketch == null) { return null; }
final ArrayOfDoublesSketch sketch = ArrayOfDoublesSketches.wrapSketch(
Memory.wrap(serializedSketch.getBytes()));
return sketch.getRetainedEntries();
}
}