akka.stream.OverflowStrategy.scala Maven / Gradle / Ivy
/*
* Copyright (C) 2009-2020 Lightbend Inc.
*/
package akka.stream
import OverflowStrategies._
import akka.annotation.{ DoNotInherit, InternalApi }
import akka.event.Logging
import akka.event.Logging.LogLevel
/**
* Represents a strategy that decides how to deal with a buffer of time based operator
* that is full but is about to receive a new element.
*/
@DoNotInherit
sealed abstract class DelayOverflowStrategy extends Serializable {
/** INTERNAL API */
@InternalApi private[akka] def isBackpressure: Boolean
}
final case class BufferOverflowException(msg: String) extends RuntimeException(msg)
/**
* Represents a strategy that decides how to deal with a buffer that is full but is
* about to receive a new element.
*/
@DoNotInherit
sealed abstract class OverflowStrategy extends DelayOverflowStrategy {
/** INTERNAL API */
@InternalApi private[akka] def logLevel: LogLevel
def withLogLevel(logLevel: Logging.LogLevel): OverflowStrategy
}
private[akka] object OverflowStrategies {
/**
* INTERNAL API
*/
private[akka] case class DropHead(logLevel: LogLevel) extends OverflowStrategy {
override def withLogLevel(logLevel: LogLevel): DropHead = DropHead(logLevel)
private[akka] override def isBackpressure: Boolean = false
}
/**
* INTERNAL API
*/
private[akka] case class DropTail(logLevel: LogLevel) extends OverflowStrategy {
override def withLogLevel(logLevel: LogLevel): DropTail = DropTail(logLevel)
private[akka] override def isBackpressure: Boolean = false
}
/**
* INTERNAL API
*/
private[akka] case class DropBuffer(logLevel: LogLevel) extends OverflowStrategy {
override def withLogLevel(logLevel: LogLevel): DropBuffer = DropBuffer(logLevel)
private[akka] override def isBackpressure: Boolean = false
}
/**
* INTERNAL API
*/
private[akka] case class DropNew(logLevel: LogLevel) extends OverflowStrategy {
override def withLogLevel(logLevel: LogLevel): DropNew = DropNew(logLevel)
private[akka] override def isBackpressure: Boolean = false
}
/**
* INTERNAL API
*/
private[akka] case class Backpressure(logLevel: LogLevel) extends OverflowStrategy {
override def withLogLevel(logLevel: LogLevel): Backpressure = Backpressure(logLevel)
private[akka] override def isBackpressure: Boolean = true
}
/**
* INTERNAL API
*/
private[akka] case class Fail(logLevel: LogLevel) extends OverflowStrategy {
override def withLogLevel(logLevel: LogLevel): Fail = Fail(logLevel)
private[akka] override def isBackpressure: Boolean = false
}
/**
* INTERNAL API
*/
private[akka] case object EmitEarly extends DelayOverflowStrategy {
private[akka] override def isBackpressure: Boolean = true
}
}
object OverflowStrategy {
/**
* If the buffer is full when a new element arrives, drops the oldest element from the buffer to make space for
* the new element.
*/
def dropHead: OverflowStrategy = DropHead(Logging.DebugLevel)
/**
* If the buffer is full when a new element arrives, drops the youngest element from the buffer to make space for
* the new element.
*/
def dropTail: OverflowStrategy = DropTail(Logging.DebugLevel)
/**
* If the buffer is full when a new element arrives, drops all the buffered elements to make space for the new element.
*/
def dropBuffer: OverflowStrategy = DropBuffer(Logging.DebugLevel)
/**
* If the buffer is full when a new element arrives, drops the new element.
*/
def dropNew: OverflowStrategy = DropNew(Logging.DebugLevel)
/**
* If the buffer is full when a new element is available this strategy backpressures the upstream publisher until
* space becomes available in the buffer.
*/
def backpressure: OverflowStrategy = Backpressure(Logging.DebugLevel)
/**
* If the buffer is full when a new element is available this strategy completes the stream with failure.
*/
def fail: OverflowStrategy = Fail(Logging.ErrorLevel)
}
object DelayOverflowStrategy {
/**
* If the buffer is full when a new element is available this strategy send next element downstream without waiting
* Will backpressure if downstream is not ready.
*/
def emitEarly: DelayOverflowStrategy = EmitEarly
/**
* If the buffer is full when a new element arrives, drops the oldest element from the buffer to make space for
* the new element.
*/
def dropHead: DelayOverflowStrategy = DropHead(Logging.DebugLevel)
/**
* If the buffer is full when a new element arrives, drops the youngest element from the buffer to make space for
* the new element.
*/
def dropTail: DelayOverflowStrategy = DropTail(Logging.DebugLevel)
/**
* If the buffer is full when a new element arrives, drops all the buffered elements to make space for the new element.
*/
def dropBuffer: DelayOverflowStrategy = DropBuffer(Logging.DebugLevel)
/**
* If the buffer is full when a new element arrives, drops the new element.
*/
def dropNew: DelayOverflowStrategy = DropNew(Logging.DebugLevel)
/**
* If the buffer is full when a new element is available this strategy backpressures the upstream publisher until
* space becomes available in the buffer.
*/
def backpressure: DelayOverflowStrategy = Backpressure(Logging.DebugLevel)
/**
* If the buffer is full when a new element is available this strategy completes the stream with failure.
*/
def fail: DelayOverflowStrategy = Fail(Logging.ErrorLevel)
}