@logging annotation for tracking method input and output

Maven Central

This repository provides a @logging annotation.

@logging annotation

This annotation inserts logging before/after invoking annotated method.

val logger = new {
    def info(s: => String): Unit =
        println(s"${LocalDateTime.now()}: $s")
}

// provide your own logger(just a `String => Unit` function)
@logging(logger.info)
def add(i: Int, j: Int): Int = {
    i + j
}

println(add(1, 2))

Outputs are below.

2017-08-19T23:05:26.279: [start]add(1, 2)
2017-08-19T23:05:26.308: [end]add(1, 2) => 3
3

Also see samples.

@timeLogging annotation

This annotation inserts logging before invoking annotated method with elapsed milli seconds.

val logger = new {
  def info(s: => String): Unit =
    println(s"${LocalDateTime.now()}: $s")
}

@timeLogging(logger.info)
def add(i: Int, j: Int): Int = {
  i + j
}
println(add(1, 2))

@timeLogging(logger.info)
def add2(i: Int)(j: Int)(): Int = {
  Thread.sleep(100)
  i + j
}

println(add2(2)(3))

2017-09-07T09:36:26.335: [start]add(1, 2)
2017-09-07T09:36:26.400: [end][0 ms]add(1, 2) => 3
3
2017-09-07T09:36:26.406: [start]add2(2)(3)()
2017-09-07T09:36:26.515: [end][107 ms]add2(2)(3)() => 5
5

Also see samples.

logging options

case class User(name: String)

@timeLogging(println, Input)
def input(name: String): User = {
    Thread.sleep(Random.nextInt(200))
    User(name)
}

@timeLogging(println, Output)
def output(name: String): User = {
    Thread.sleep(Random.nextInt(200))
    User(name)
}

@timeLogging(println, Simple)
def simple(name: String): User = {
    Thread.sleep(Random.nextInt(200))
    User(name)
}

@timeLogging(println, Full)
def full(name: String): User = {
    Thread.sleep(Random.nextInt(200))
    User(name)
}

simple("simple")
input("input")
output("output")
full("full")

[start]simple(...)
[end][41 ms]simple(...) => (...)
[start]input(input)
[end][113 ms]input(input) => (...)
[start]output(...)
[end][32 ms]output(...) => User(output)
[start]full(full)
[end][160 ms]full(full) => User(full)

setup

in build.sbt

lazy val metaMacroSettings: Seq[Def.Setting[_]] = Seq(
  resolvers += Resolver.sonatypeRepo("releases"),
  resolvers += Resolver.bintrayIvyRepo("scalameta", "maven"),
  addCompilerPlugin("org.scalameta" % "paradise" % "3.0.0-M9" cross CrossVersion.full),
  scalacOptions ++= Seq(
    "-Xplugin-require:macroparadise",
    // "-Ymacro-debug-lite" // for debug
  )
)

project.settings(
  metaMacroSettings,
  libraryDependencies += "net.petitviolet" %% "mlogging" % "<latest-version>"
)

License

MIT License