/**
* 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.io.IntWritable;
import org.apache.hadoop.io.Text;
/**
* UDFFindInSet.
*
*/
@Description(name = "find_in_set", value = "_FUNC_(str,str_array) - Returns the first occurrence "
+ " of str in str_array where str_array is a comma-delimited string."
+ " Returns null if either argument is null."
+ " Returns 0 if the first argument has any commas.", extended = "Example:\n"
+ " > SELECT _FUNC_('ab','abc,b,ab,c,def') FROM src LIMIT 1;\n"
+ " 3\n"
+ " > SELECT * FROM src1 WHERE NOT _FUNC_(key,'311,128,345,956')=0;\n"
+ " 311 val_311\n" + " 128"
)
public class UDFFindInSet extends UDF {
private final IntWritable result = new IntWritable();
public IntWritable evaluate(Text s, Text txtarray) {
if (s == null || txtarray == null) {
return null;
}
byte[] search_bytes = s.getBytes();
for (int i = 0; i < s.getLength(); i++) {
if (search_bytes[i] == ',') {
result.set(0);
return result;
}
}
byte[] data = txtarray.getBytes();
int search_length = s.getLength();
int cur_pos_in_array = 0;
int cur_length = 0;
boolean matching = true;
for (int i = 0; i < txtarray.getLength(); i++) {
if (data[i] == ',') {
cur_pos_in_array++;
if (matching && cur_length == search_length) {
result.set(cur_pos_in_array);
return result;
} else {
matching = true;
cur_length = 0;
}
} else {
if (cur_length + 1 <= search_length) {
if (!matching || search_bytes[cur_length] != data[i]) {
matching = false;
}
} else {
matching = false;
}
cur_length++;
}
}
if (matching && cur_length == search_length) {
cur_pos_in_array++;
result.set(cur_pos_in_array);
return result;
} else {
result.set(0);
return result;
}
}
}