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@jrudolph
jrudolph / SimpleQuicClientMain.scala
Last active February 20, 2020 16:45
"Simple" "Http/3" "client"
import java.math.BigInteger
import java.net.DatagramPacket
import java.net.DatagramSocket
import java.net.InetAddress
import java.security.KeyPairGenerator
import java.security.MessageDigest
import java.security.SecureRandom
import java.security.interfaces.ECPrivateKey
import java.security.interfaces.ECPublicKey
import java.security.spec.ECPoint
@jrudolph
jrudolph / JmhCompletion.scala
Created April 30, 2019 21:05
A smart sbt parser for the most used jmh parameters (copy to project dir and use jmh:runny)
package akka.sbt.jmh.completion
import java.io.FileInputStream
import java.util.Collections
import pl.project13.scala.sbt.SbtJmh.JmhKeys.Jmh
import sbt._
import Keys._
import org.openjdk.jmh.runner.BenchmarkList
import org.openjdk.jmh.runner.BenchmarkListEntry
@jrudolph
jrudolph / script.sh
Created October 11, 2018 09:39
Biometrisches Passfoto erstellen zum selbst Ausdrucken
# use persofoto.de to crop a foto to the right dimensions
# then use this script to lay it out on a 1600x2312 jpg to print as 9x13
montage mein-passfoto.jpg mein-passfoto.jpg mein-passfoto.jpg mein-passfoto.jpg -geometry 622x898+89+129 out.jpg
@jrudolph
jrudolph / THX.scala
Created September 8, 2018 11:04
8-bit THX Deep Note sound generation with Scala
import java.util.concurrent.ThreadLocalRandom
import javax.sound.sampled._
// Program to generate THX Deep Note sound according to the sheet music
// published to celebrate its 35th birthday
// https://twitter.com/THX/status/1000077588415447040
object THX extends App {
val sampleRate = 44100f
val af = new AudioFormat(
sampleRate,
@jrudolph
jrudolph / GraphStageOrGraphDSL.md
Created December 18, 2017 16:28
Should I use GraphStage or GraphDSL?

In general, performance differences are usually negligible as long as they don't turn up during benchmarking (you probably know what people say about premature optimization...).

So, it's mostly a matter of style. Writing a GraphStage is the lowest level you can implement something in akka-stream. It's very explicit and somewhat predictable what happens but the amount of code to write can be quite cumbersome and with a growing number of ports, managing the state space and all the possible interactions can be quite a challenge.

Wiring up predefined combinators using the GraphDSL is therefore often recommended. In the best case it's just "plug and play". On the other hand, it also introduces new degrees of freedom and non-determinism as elements flow

@jrudolph
jrudolph / CleanupImports.scala
Last active January 17, 2018 13:07
Cleanup Imports for sbt 1.0
/*
* Copyright (C) 2009-2017 Lightbend Inc. <http://www.lightbend.com>
*/
import sbt._
import Keys._
package sbt {
object Access {
def compilerReporter = sbt.Keys.compilerReporter
@jrudolph
jrudolph / analysis.txt
Last active April 6, 2021 16:54
Scala 2.13 Release Train
TargetVersion: Scala 2.13 LastVersion: Scala 2.12
@jrudolph
jrudolph / StackDumpAnalyzer.scala
Created September 27, 2017 16:04
Ongoing effort to parse stack dumps generated e.g. by jstack or the JVM directly
import java.io.File
import scala.io.Source
object StackDumpAnalyzer extends App {
val ThreadLine = """"([^"]+)" #(\d+) prio=(\d+) os_prio=(\d+) tid=0x([0-9a-f]+) nid=0x([0-9a-f]+) (.*)""".r
val file = "ThreadDump.txt"
case class ThreadState(name: String, id: Int, prio: Int, osPrio: Int, tid: Long, nid: Int, state: String)
@jrudolph
jrudolph / SuperInspectTree.scala
Last active October 1, 2019 19:40
Better sbt `inspect tree`
/* sbt -- Simple Build Tool
* Copyright 2011 Mark Harrah, Eugene Yokota
*/
package sbt
package myinspect
import java.io.File
import Def.{ScopedKey, compiled, flattenLocals}
@jrudolph
jrudolph / AffinityVsFJP.log
Created July 20, 2017 13:05
Benchmark new Affinity Vs FJP dispatcher
Intel(R) Core(TM) i7-3840QM CPU @ 2.80GHz
Turbo off
Linux 64bit
jmh:run -i 4 -wi 4 -f 1 -p throughPut=1 -p dispatcher=affinity-dispatcher,default-fj-dispatcher .*AffinityPoolReq.*
[info] Benchmark (dispatcher) (mailbox) (throughPut) Mode Cnt Score Error Units
[info] AffinityPoolRequestResponseBenchmark.queryUserServiceActor affinity-dispatcher SingleConsumerOnlyUnboundedMailbox 1 thrpt 4 3634030.863 ± 3728431.081 ops/s
[info] AffinityPoolRequestResponseBenchmark.queryUserServiceActor default-fj-dispatcher SingleConsumerOnlyUnboundedMailbox 1 thrpt 4 4031047.752 ± 1552394.546 ops/s