org.apache.hadoop.hive.ql.exec.vector.expressions.MathExpr Maven / Gradle / Ivy
/**
* 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.exec.vector.expressions;
import org.apache.hadoop.hive.ql.exec.vector.DoubleColumnVector;
/**
* Math expression evaluation helper functions.
* Some of these are referenced from ColumnUnaryFunc.txt.
*/
public class MathExpr {
// Round using the "half-up" method used in Hive.
public static double round(double d) {
if (d > 0.0) {
return (double) ((long) (d + 0.5d));
} else {
return (double) ((long) (d - 0.5d));
}
}
public static double log2(double d) {
return Math.log(d) / Math.log(2);
}
public static long abs(long v) {
return v >= 0 ? v : -v;
}
public static double sign(double v) {
if (v == 0) {
return 0;
} else if (v > 0) {
return 1.0;
} else {
return -1.0;
}
}
public static double sign(long v) {
if (v == 0) {
return 0;
} else if (v > 0) {
return 1.0;
} else {
return -1.0;
}
}
// for casting integral types to boolean
public static long toBool(long v) {
return v == 0 ? 0 : 1;
}
// for casting floating point types to boolean
public static long toBool(double v) {
return v == 0.0D ? 0L : 1L;
}
/* Convert an integer value in seconds since the epoch to a timestamp value
* for use in a long column vector, which is represented in nanoseconds since the epoch.
*/
public static long longToTimestamp(long v) {
return v * 1000000000;
}
/* Convert an integer value in milliseconds since the epoch to a timestamp value
* for use in a long column vector, which is represented in nanoseconds since the epoch.
*/
public static long millisecondsLongToTimestamp(long v) {
return v * 1000000;
}
// Convert seconds since the epoch (with fraction) to nanoseconds, as a long integer.
public static long doubleToTimestamp(double v) {
return (long)( v * 1000000000.0);
}
/* Convert an integer value representing a timestamp in nanoseconds to one
* that represents a timestamp in seconds (since the epoch).
*/
public static long fromTimestamp(long v) {
return v / 1000000000;
}
/* Convert an integer value representing a timestamp in nanoseconds to one
* that represents a timestamp in seconds, with fraction, since the epoch.
*/
public static double fromTimestampToDouble(long v) {
return ((double) v) / 1000000000.0;
}
/* Convert a long to a string. The string is output into the argument
* byte array, beginning at character 0. The length is returned.
*/
public static int writeLongToUTF8(byte[] result, long i) {
if (i == 0) {
result[0] = '0';
return 1;
}
int current = 0;
if (i < 0) {
result[current++] ='-';
} else {
// negative range is bigger than positive range, so there is no risk
// of overflow here.
i = -i;
}
long start = 1000000000000000000L;
while (i / start == 0) {
start /= 10;
}
while (start > 0) {
result[current++] = (byte) ('0' - (i / start % 10));
start /= 10;
}
return current;
}
// Convert all NaN values in vector v to NULL. Should only be used if n > 0.
public static void NaNToNull(DoubleColumnVector v, int[] sel, boolean selectedInUse, int n) {
NaNToNull(v, sel, selectedInUse, n, false);
}
// Convert all NaN, and optionally infinity values in vector v to NULL.
// Should only be used if n > 0.
public static void NaNToNull(
DoubleColumnVector v, int[] sel, boolean selectedInUse, int n, boolean convertInfinity) {
// handle repeating case
if (v.isRepeating) {
if ((convertInfinity && Double.isInfinite(v.vector[0])) || Double.isNaN(v.vector[0])){
v.vector[0] = DoubleColumnVector.NULL_VALUE;
v.isNull[0] = true;
v.noNulls = false;
}
return;
}
if (v.noNulls) {
if (selectedInUse) {
for(int j = 0; j != n; j++) {
int i = sel[j];
if ((convertInfinity && Double.isInfinite(v.vector[i])) || Double.isNaN(v.vector[i])) {
v.vector[i] = DoubleColumnVector.NULL_VALUE;
v.isNull[i] = true;
v.noNulls = false;
} else {
// Must set isNull[i] to false to make sure
// it gets initialized, in case we set noNulls to true.
v.isNull[i] = false;
}
}
} else {
for(int i = 0; i != n; i++) {
if ((convertInfinity && Double.isInfinite(v.vector[i])) || Double.isNaN(v.vector[i])) {
v.vector[i] = DoubleColumnVector.NULL_VALUE;
v.isNull[i] = true;
v.noNulls = false;
} else {
v.isNull[i] = false;
}
}
}
} else { // there are nulls, so null array entries are already initialized
if (selectedInUse) {
for (int j = 0; j != n; j++) {
int i = sel[j];
if((convertInfinity && Double.isInfinite(v.vector[i])) || Double.isNaN(v.vector[i])) {
v.vector[i] = DoubleColumnVector.NULL_VALUE;
v.isNull[i] = true;
}
}
} else {
for (int i = 0; i != n; i++) {
if((convertInfinity && Double.isInfinite(v.vector[i])) || Double.isNaN(v.vector[i])) {
v.vector[i] = DoubleColumnVector.NULL_VALUE;
v.isNull[i] = true;
}
}
}
}
}
}