calvinlfer’s gists

calvinlfer / Playground.scala

Last active February 21, 2025 17:45

Ship ZIO Metrics to OpenTelemetry (OLTP gRPC) using zio-telemetry-opentelemetry by manually providing the instrumentation (this portion connects ZIO Metrics to the ZIO Opentelemetry machinery). I also have an example that uses auto-instrumentation

	import zio.*
	import zio.telemetry.opentelemetry.OpenTelemetry
	import io.opentelemetry.sdk.OpenTelemetrySdk
	import io.opentelemetry.api.metrics.MeterProvider
	import io.opentelemetry.sdk.metrics.SdkMeterProvider
	import io.opentelemetry.exporter.otlp.metrics.OtlpGrpcMetricExporter
	import io.opentelemetry.exporter.otlp.logs.OtlpGrpcLogRecordExporter
	import io.opentelemetry.sdk.metrics.`export`.PeriodicMetricReader
	import io.opentelemetry.sdk.resources.Resource as OltpResource
	import zio.metrics.Metric

calvinlfer / partition.scala

Created January 28, 2025 23:28 — forked from soujiro32167/partition.scala

A generic partitioning of a list of enums

	//> using scala 3.6.3

	import scala.deriving.Mirror
	import scala.compiletime.{erasedValue}

	/** Type-level function that transforms a type-level tuple of types
	* into a corresponding tuple of List[...] at the value level.
	*
	* E.g., if Ts is (T1, T2, T3), Partitioned[Ts] is (List[T1], List[T2], List[T3]).
	*/

calvinlfer / HelidonExample.scala

Created December 11, 2024 20:50

Integrating the Helidon Kafka client with FS2 Streams using the interop flow package

	import cats.syntax.parallel.*
	import cats.effect.*
	import fs2.*
	import fs2.interop.flow.*
	import io.helidon.config.Config
	import io.helidon.messaging.connectors.kafka.KafkaConfigBuilder.AutoOffsetReset
	import io.helidon.messaging.connectors.kafka.{KafkaConnector as HelidonKafkaConnector, KafkaMessage, KafkaPublisher as HelidonKafkaConsumer}
	import org.apache.kafka.common.serialization.StringDeserializer
	import org.reactivestreams.FlowAdapters

calvinlfer / example.sh

Created November 20, 2024 17:58

SBT on Alpine Linux using Coursier

	apk add --update openjdk21 curl

	# Use JAR based launcher: https://get-coursier.io/docs/cli-installation#linux--macos
	curl -fLo coursier https://github.com/coursier/launchers/raw/master/coursier
	chmod +x coursier

	# Install SBT
	./coursier install sbt

	# https://get-coursier.io/docs/cli-launch#java-options

calvinlfer / InterruptibleReadLineExample.scala

Created September 27, 2024 20:14

An example of how to achieve an interruptible readLine with ZIO

	import zio.*
	import scala.Console as SConsole
	import scala.io.StdIn
	import java.io.{BufferedReader, IOException}
	import scala.util.Try

	object InterruptibleReadLineExample extends ZIOAppDefault {

	def altReadLine(reader: BufferedReader = SConsole.in) =
	ZIO

calvinlfer / KyoPlayground.scala

Created September 21, 2024 23:26

Modelling lazy infinite streams in Kyo 0.12.x (https://getkyo.io/#/?id=stream-composable-data-processing)

	import kyo.*
	import kyo.Emit.Ack

	object Playground extends KyoApp:
	def recursiveStream(start: Int): Stream[Int, IO] =
	def go(n: Int): Ack < Emit[Chunk[Int]] =
	Emit.andMap(Chunk(n)):
	case Ack.Stop => Ack.Stop
	case Ack.Continue(_) => go(n + 1)

calvinlfer / Avro4sDeserializer.scala

Created June 8, 2024 17:37

FS2 Kafka Avro4S support (Schema Registry aware)

	import com.sksamuel.avro4s.{Decoder, SchemaFor}
	import fs2.kafka.{Deserializer, ValueDeserializer, KeyDeserializer}
	import fs2.kafka.vulcan.AvroSettings
	import cats.effect.{Sync, Resource}
	import java.nio.ByteBuffer
	import io.confluent.kafka.schemaregistry.avro.AvroSchema

	final class Avro4sDeserializer[A >: Null](
	private val decoder: Decoder[A],
	private val schemaFor: SchemaFor[A]

calvinlfer / nextlevel.scala

Created May 27, 2023 14:31

Virgil ideas

	package io.kaizensolutions.virgil.nextlevel

	import io.kaizensolutions.virgil.nextlevel.nextlevel.peopleTable

	object nextlevel {

	sealed trait Table {
	type TableTag
	}
	object Table {

calvinlfer / build-native-image.sh

Created May 8, 2023 13:06

ZIO HTTP (Graal Native Image & Scala CLI)

	#!/bin/sh

	scala-cli --power package --native-image -f *.scala -o ziohttp.bin -- --no-fallback --enable-url-protocols=http,https -Djdk.http.auth.tunneling.disabledSchemes= --install-exit-handlers --enable-http --initialize-at-run-time=io.netty.channel.DefaultFileRegion --initialize-at-run-time=io.netty.channel.epoll.Native --initialize-at-run-time=io.netty.channel.epoll.Epoll --initialize-at-run-time=io.netty.channel.epoll.EpollEventLoop --initialize-at-run-time=io.netty.channel.epoll.EpollEventArray --initialize-at-run-time=io.netty.channel.kqueue.KQueue --initialize-at-run-time=io.netty.channel.kqueue.KQueueEventLoop --initialize-at-run-time=io.netty.channel.kqueue.KQueueEventArray --initialize-at-run-time=io.netty.channel.kqueue.Native --initialize-at-run-time=io.netty.channel.unix.Limits --initialize-at-run-time=io.netty.channel.unix.Errors --initialize-at-run-time=io.netty.channel.unix.IovArray --initialize-at-run-time=io.netty.handler.codec.compression.ZstdOptions --initialize-at-run-time=io.netty.incub

calvinlfer / ZioHttpServerTracer.scala

Created February 17, 2023 19:42

getting tracing to work with zio-http 0.0.4's new Handler abstraction

	package io.kaizensolutions.trace4cats.zio.extras.ziohttp.server

	import trace4cats.ErrorHandler
	import trace4cats.model.AttributeValue.{LongValue, StringValue}
	import trace4cats.model.SemanticAttributeKeys.*
	import trace4cats.model.{AttributeValue, SpanKind, SpanStatus}
	import io.kaizensolutions.trace4cats.zio.extras.ZTracer
	import io.kaizensolutions.trace4cats.zio.extras.ziohttp.{extractTraceHeaders, toSpanStatus}
	import zio.*
	import zio.http.*

Calvin Lee Fernandes calvinlfer