mirror of
https://github.com/twitter/the-algorithm.git
synced 2024-06-01 08:48:46 +02:00
35 lines
1.1 KiB
Scala
35 lines
1.1 KiB
Scala
package com.twitter.servo.gate
|
|
|
|
import com.twitter.decider
|
|
import com.twitter.servo.util.Gate
|
|
import scala.annotation.tailrec
|
|
|
|
object DeciderGate {
|
|
|
|
/**
|
|
* Create a Gate[Unit] with a probability of returning true
|
|
* that increases linearly with the availability of feature.
|
|
*/
|
|
def linear(feature: decider.Feature): Gate[Unit] =
|
|
Gate(_ => feature.isAvailable, "DeciderGate.linear(%s)".format(feature))
|
|
|
|
/**
|
|
* Create a Gate[Unit] with a probability of returning true
|
|
* that increases exponentially with the availability of feature.
|
|
*/
|
|
def exp(feature: decider.Feature, exponent: Int): Gate[Unit] = {
|
|
val gate = if (exponent >= 0) linear(feature) else !linear(feature)
|
|
|
|
@tailrec
|
|
def go(exp: Int): Boolean = if (exp == 0) true else (gate() && go(exp - 1))
|
|
|
|
Gate(_ => go(math.abs(exponent)), "DeciderGate.exp(%s, %s)".format(feature, exponent))
|
|
}
|
|
|
|
/**
|
|
* Create a Gate[Long] that returns true if the given feature is available for an id.
|
|
*/
|
|
def byId(feature: decider.Feature): Gate[Long] =
|
|
Gate(id => feature.isAvailable(id), "DeciderGate.byId(%s)".format(feature))
|
|
}
|