org.apache.hadoop.hive.ql.udf.UDFHex Maven / Gradle / Ivy
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* 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;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedExpressions;
import org.apache.hadoop.hive.ql.exec.vector.expressions.FuncHex;
import org.apache.hadoop.hive.ql.exec.vector.expressions.StringUnaryUDF.IUDFUnaryString;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
/**
* UDFHex.
*
*/
@Description(name = "hex",
value = "_FUNC_(n, bin, or str) - Convert the argument to hexadecimal ",
extended = "If the argument is a string, returns two hex digits for each "
+ "character in the string.\n"
+ "If the argument is a number or binary, returns the hexadecimal representation.\n"
+ "Example:\n"
+ " > SELECT _FUNC_(17) FROM src LIMIT 1;\n"
+ " 'H1'\n"
+ " > SELECT _FUNC_('Facebook') FROM src LIMIT 1;\n"
+ " '46616365626F6F6B'")
@VectorizedExpressions({FuncHex.class})
public class UDFHex extends UDF implements IUDFUnaryString {
private final Text result = new Text();
private byte[] value = new byte[16];
/**
* Convert num to hex.
*
*/
private Text evaluate(long num) {
// Extract the hex digits of num into value[] from right to left
int len = 0;
do {
len++;
value[value.length - len] = (byte) Character.toUpperCase(Character
.forDigit((int) (num & 0xF), 16));
num >>>= 4;
} while (num != 0);
result.set(value, value.length - len, len);
return result;
}
public Text evaluate(LongWritable n) {
if (n == null) {
return null;
}
return evaluate(n.get());
}
public Text evaluate(IntWritable n) {
if (n == null) {
return null;
}
return evaluate(n.get());
}
/**
* Convert every character in s to two hex digits.
*
*/
public Text evaluate(Text s) {
if (s == null) {
return null;
}
byte[] str = s.getBytes();
return evaluate(str, s.getLength());
}
/**
* Convert bytes to a hex string
*/
public Text evaluate(BytesWritable b){
if (b == null) {
return null;
}
byte[] bytes = b.getBytes();
return evaluate(bytes, b.getLength());
}
private Text evaluate(byte[] bytes, int length){
if (value.length < length * 2) {
value = new byte[length * 2];
}
for (int i = 0; i < length; i++) {
value[i * 2] = (byte) Character.toUpperCase(Character.forDigit(
(bytes[i] & 0xF0) >>> 4, 16));
value[i * 2 + 1] = (byte) Character.toUpperCase(Character.forDigit(
bytes[i] & 0x0F, 16));
}
result.set(value, 0, length*2);
return result;
}
}