korolev.state.IdGenerator.scala Maven / Gradle / Ivy
/*
* Copyright 2017-2020 Aleksey Fomkin
*
* Licensed 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 korolev.state
import java.security.SecureRandom
import korolev.effect.Effect
trait IdGenerator[F[_]] {
def generateDeviceId()(implicit F: Effect[F]): F[DeviceId]
def generateSessionId()(implicit F: Effect[F]): F[SessionId]
}
object IdGenerator {
val DefaultDeviceIdLength = 16
val DefaultSessionIdLength = 8
def default[F[_]](deviceIdLength: Int = DefaultDeviceIdLength,
sessionIdLength: Int = DefaultSessionIdLength): IdGenerator[F] =
new DefaultIdGenerator[F](deviceIdLength, sessionIdLength)
private class DefaultIdGenerator[F[_]](deviceIdLength: Int,
sessionIdLength: Int) extends IdGenerator[F] {
def generateDeviceId()(implicit F: Effect[F]): F[DeviceId] =
Effect[F].delay {
secureRandomString(deviceIdLength)
}
def generateSessionId()(implicit F: Effect[F]): F[SessionId] =
Effect[F].delay {
secureRandomString(sessionIdLength)
}
private val Alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
private val rnd = new SecureRandom
private def secureRandomString(len: Int): String = {
val sb = new StringBuilder(len)
var i = 0
while (i < len) {
sb.append(Alphabet.charAt(rnd.nextInt(Alphabet.length)))
i += 1
}
sb.toString
}
}
}