com.snowplowanalytics.snowplow.sources.internal.Checkpointer.scala Maven / Gradle / Ivy
/*
* Copyright (c) 2023-present Snowplow Analytics Ltd. All rights reserved.
*
* This program is licensed to you under the Snowplow Community License Version 1.0,
* and you may not use this file except in compliance with the Snowplow Community License Version 1.0.
* You may obtain a copy of the Snowplow Community License Version 1.0 at https://docs.snowplow.io/community-license-1.0
*/
package com.snowplowanalytics.snowplow.sources.internal
import cats.{Applicative, Monoid}
/**
* Checkpoints messages to the input stream so that we don't read them again. A single checkpointer
* might be responsible for multiple incoming messages.
* @tparam F
* An effect
* @tparam C
* Source-specific type describing the outstading messages
*/
trait Checkpointer[F[_], C] extends Monoid[C] {
/** Trigger checkpointing. Must be called only when all message processing is complete */
def ack(c: C): F[Unit]
/** Nack un-processed messages. Used during shutdown */
def nack(c: C): F[Unit]
}
object Checkpointer {
/** A simple implementation that does ack only and no nacks */
def acksOnly[F[_]: Applicative, C: Monoid](f: C => F[Unit]): Checkpointer[F, C] =
new Checkpointer[F, C] {
override def ack(c: C): F[Unit] = f(c)
override def nack(c: C): F[Unit] = Applicative[F].unit
override def empty: C = Monoid[C].empty
override def combine(x: C, y: C): C = Monoid[C].combine(x, y)
}
}