org.apache.spark.sql.catalyst.util.RandomUUIDGenerator.scala 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.spark.sql.catalyst.util
import java.util.UUID
import org.apache.commons.math3.random.MersenneTwister
import org.apache.spark.unsafe.types.UTF8String
/**
* This class is used to generate a UUID from Pseudo-Random Numbers.
*
* For the algorithm, see RFC 4122: A Universally Unique IDentifier (UUID) URN Namespace,
* section 4.4 "Algorithms for Creating a UUID from Truly Random or Pseudo-Random Numbers".
*/
case class RandomUUIDGenerator(randomSeed: Long) {
private val random = new MersenneTwister(randomSeed)
def getNextUUID(): UUID = {
val mostSigBits = (random.nextLong() & 0xFFFFFFFFFFFF0FFFL) | 0x0000000000004000L
val leastSigBits = (random.nextLong() | 0x8000000000000000L) & 0xBFFFFFFFFFFFFFFFL
new UUID(mostSigBits, leastSigBits)
}
def getNextUUIDUTF8String(): UTF8String = UTF8String.fromString(getNextUUID().toString())
}