org.apache.hadoop.hive.ql.exec.vector.expressions.VectorUDFYearLong Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hive.ql.exec.vector.expressions;
import java.util.Arrays;
import java.util.Calendar;
/**
* Expression to get year as a long.
* Extends {@link VectorUDFTimestampFieldLong}
*/
public final class VectorUDFYearLong extends VectorUDFTimestampFieldLong {
private static final long serialVersionUID = 1L;
/* year boundaries in nanoseconds */
private static transient final long[] YEAR_BOUNDARIES;
private static transient final int MIN_YEAR = 1678;
private static transient final int MAX_YEAR = 2300;
static {
YEAR_BOUNDARIES = new long[MAX_YEAR-MIN_YEAR];
Calendar c = Calendar.getInstance();
c.setTimeInMillis(0); // c.set doesn't reset millis
/* 1901 Jan is not with in range */
for(int year=MIN_YEAR+1; year <= MAX_YEAR; year++) {
c.set(year, Calendar.JANUARY, 1, 0, 0, 0);
YEAR_BOUNDARIES[year-MIN_YEAR-1] = c.getTimeInMillis()*1000*1000;
}
}
@Override
protected long getTimestampField(long time) {
/* binarySearch is faster than a loop doing a[i] (no array out of bounds checks) */
int year = Arrays.binarySearch(YEAR_BOUNDARIES, time);
if(year >= 0) {
/* 0 == 1902 etc */
return MIN_YEAR + 1 + year;
} else {
/* -1 == 1901, -2 == 1902 */
return MIN_YEAR - 1 - year;
}
}
public VectorUDFYearLong(int colNum, int outputColumn) {
super(Calendar.YEAR, colNum, outputColumn);
}
public VectorUDFYearLong() {
super();
}
}