fs2.kafka.consumer.MkConsumer.scala Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of fs2-kafka_2.12 Show documentation

fs2-kafka

The newest version!

/*
 * Copyright 2018-2024 OVO Energy Limited
 *
 * SPDX-License-Identifier: Apache-2.0
 */

package fs2.kafka.consumer

import cats.effect.Sync
import fs2.kafka.{ConsumerSettings, KafkaByteConsumer}
import fs2.kafka.internal.converters.collection.*

import org.apache.kafka.common.serialization.ByteArrayDeserializer

/**
  * A capability trait representing the ability to instantiate the Java `Consumer` that underlies
  * the fs2-kafka `KafkaConsumer`. This is needed in order to instantiate
  * [[fs2.kafka.KafkaConsumer]].


  *
  * By default, the instance provided by [[MkConsumer.mkConsumerForSync]] will be used. However this
  * behaviour can be overridden, e.g. for testing purposes, by placing an alternative implicit
  * instance in lexical scope.
  */
trait MkConsumer[F[_]] {
  def apply[G[_]](settings: ConsumerSettings[G, ?, ?]): F[KafkaByteConsumer]
}

object MkConsumer {

  implicit def mkConsumerForSync[F[_]](implicit F: Sync[F]): MkConsumer[F] =
    new MkConsumer[F] {

      def apply[G[_]](settings: ConsumerSettings[G, ?, ?]): F[KafkaByteConsumer] = F.delay {
        val byteArrayDeserializer = new ByteArrayDeserializer
        new org.apache.kafka.clients.consumer.KafkaConsumer(
          (settings.properties: Map[String, AnyRef]).asJava,
          byteArrayDeserializer,
          byteArrayDeserializer
        )
      }

    }

}