Experimenting scala logging approach. / published by https://github.com/dacr/code-examples-manager #db278342-7a77-4013-9609-b74ad5a4f8e0/d35a81a1c8bf16ef08810e23ecca0c9640429648

logging-enhancement-experiment.sc

// summary : Experimenting scala logging approach.
// keywords : scala, logs, experiment
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : db278342-7a77-4013-9609-b74ad5a4f8e0
// created-on : 2020-05-31T19:54:52Z
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.4.2"
// ---------------------

def now() = System.currentTimeMillis

case class LogContext(tuples: Map[LogContext.TagKey, LogContext.TagValue])

object LogContext {
  type TagKey   = Symbol
  type TagValue = String
  type TagTuple = Tuple2[TagKey, TagValue]
  def apply(tuples: TagTuple*): LogContext                                            = LogContext(tuples.toMap)
  implicit def tuplesArray2LogContext(tuples: Array[LogContext.TagTuple]): LogContext = LogContext(tuples.toMap)
}

def log(msg: String)(implicit ctx: LogContext) = println(msg + " " + ctx.tuples.toString)

def logprov[T](proc: ((String) => Any) => T)(implicit ctx: LogContext): T = proc(log(_))

def logaround[T](what: String)(proc: => T)(implicit ctx: LogContext): T = {
  log(s"$what starts")
  val result = proc
  log(s"$what ends")
  result
}

def logperf[T](msg: String)(proc: => T)(implicit ctx: LogContext): T = {
  val started = now()
  val result  = proc
  val ended   = now() - started
  log(s"$msg")(new LogContext(ctx.tuples + (Symbol("duration") -> ended.toString)))
  result
}

// ---------------------------------------------------------------------

implicit val ctx: LogContext = LogContext(Symbol("pid") -> "32", Symbol("client") -> "toto", Symbol("logger") -> "dummy")

log("1.coucou")

logprov { logger =>
  // some initialization
  logger("2.ready")
  // some processing
  logger("2.do it")
  // some other thing
}

logperf("3.howmuchtime") {
  // some synchronous potentially long processing
  Thread.sleep(200)
}

logaround("4.complex processing") {
  // do some very complex processing
  1 + 1
}

/*
val eventualFuture = Future(1+1)
logfut("5.some future result")(eventualFuture)
  .map(
// TO BE CONTINUED...
 */