swaydb.core.brake.BrakePedal.scala Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of core_2.13 Show documentation
core
The newest version!
/*
 * Copyright (c) 2020 Simer JS Plaha ([email protected] - @simerplaha)
 *
 * This file is a part of SwayDB.
 *
 * SwayDB is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * SwayDB is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with SwayDB. If not, see .
 *
 * Additional permission under the GNU Affero GPL version 3 section 7:
 * If you modify this Program or any covered work, only by linking or combining
 * it with separate works, the licensors of this Program grant you additional
 * permission to convey the resulting work.
 */

package swaydb.core.brake

import com.typesafe.scalalogging.LazyLogging

import scala.concurrent.duration._

private[core] class BrakePedal(private var brakeFor: FiniteDuration,
                               releaseRate: FiniteDuration,
                               logAsWarning: Boolean) extends LazyLogging {

  /**
   * Blocking back-pressure.
   *
   * Blocks current thread and decrements the next block with the release rate.
   *
   * @return true if the brake is complete else false.
   */
  def applyBrakes(): Boolean = {
    if (logAsWarning)
      logger.warn(s"Blocking-backpressure - Braking for: $brakeFor.")

    Thread.sleep(brakeFor.toMillis)
    brakeFor = brakeFor - releaseRate

    val isOverdue = brakeFor.fromNow.isOverdue()

    if(logAsWarning && isOverdue)
      logger.warn(s"Blocking-backpressure - Brake released!")

    isOverdue
  }

  def isReleased(): Boolean =
    brakeFor.fromNow.isOverdue()

  def isBraking(): Boolean =
    brakeFor.fromNow.hasTimeLeft()
}