A few attempts at micro-optimizing the current hot spots

4 files changed, 36 insertions, 23 deletions

diff --git a/core/src/mill/define/Module.scala b/core/src/mill/define/Module.scala
index 93537f76..0f8e96ce 100644
--- a/core/src/mill/define/Module.scala
+++ b/core/src/mill/define/Module.scala
@@ -56,22 +56,25 @@ object Module{
     lazy val millModuleLine = outer.millOuterCtx.lineNum
 
     def reflect[T: ClassTag] = {
-      outer
-        .getClass
-        .getMethods
-        .filter(!_.getName.contains('$'))
-        .filter(_.getParameterCount == 0)
-        .filter(x => (x.getModifiers & Modifier.STATIC) == 0)
-        .filter(implicitly[ClassTag[T]].runtimeClass isAssignableFrom _.getReturnType)
-        .map(_.invoke(outer).asInstanceOf[T])
+      val runtimeCls = implicitly[ClassTag[T]].runtimeClass
+      for{
+        m <- outer.getClass.getMethods
+        if
+          !m.getName.contains('$') &&
+          m.getParameterCount == 0 &&
+          (m.getModifiers & Modifier.STATIC) == 0 &&
+          runtimeCls.isAssignableFrom(m.getReturnType)
+      } yield m.invoke(outer).asInstanceOf[T]
+
     }
     def reflectNames[T: ClassTag] = {
-      outer
-        .getClass
-        .getMethods
-        .filter(x => (x.getModifiers & Modifier.STATIC) == 0)
-        .filter(implicitly[ClassTag[T]].runtimeClass isAssignableFrom _.getReturnType)
-        .map(_.getName)
+      val runtimeCls = implicitly[ClassTag[T]].runtimeClass
+      for{
+        m <- outer.getClass.getMethods
+        if
+          (m.getModifiers & Modifier.STATIC) == 0 &&
+          runtimeCls.isAssignableFrom(m.getReturnType)
+      } yield m.getName
     }
     // For some reason, this fails to pick up concrete `object`s nested directly within
     // another top-level concrete `object`. This is fine for now, since Mill's Ammonite
diff --git a/core/src/mill/eval/Evaluator.scala b/core/src/mill/eval/Evaluator.scala
index 57d39a24..42015c6f 100644
--- a/core/src/mill/eval/Evaluator.scala
+++ b/core/src/mill/eval/Evaluator.scala
@@ -32,7 +32,7 @@ case class Evaluator[T](outPath: Path,
                         log: Logger,
                         classLoaderSig: Seq[(Path, Long)] = Evaluator.classLoaderSig,
                         workerCache: mutable.Map[Segments, (Int, Any)] = mutable.Map.empty){
-
+  val classLoaderSignHash = classLoaderSig.hashCode()
   def evaluate(goals: Agg[Task[_]]): Evaluator.Results = {
     mkdir(outPath)
 
@@ -82,7 +82,12 @@ case class Evaluator[T](outPath: Path,
     for (((terminal, group), i) <- sortedGroups.items().zipWithIndex){
       // Increment the counter message by 1 to go from 1/10 to 10/10 instead of 0/10 to 9/10
       val counterMsg = (i+1) + "/" + sortedGroups.keyCount
-      val (newResults, newEvaluated) = evaluateGroupCached(terminal, group, results, counterMsg)
+      val (newResults, newEvaluated) = evaluateGroupCached(
+        terminal,
+        group,
+        results,
+        counterMsg)
+
       for(ev <- newEvaluated){
         evaluated.append(ev)
       }
@@ -114,13 +119,16 @@ case class Evaluator[T](outPath: Path,
                           results: collection.Map[Task[_], Result[(Any, Int)]],
                           counterMsg: String): (collection.Map[Task[_], Result[(Any, Int)]], Seq[Task[_]]) = {
 
+    val externalInputsHash = scala.util.hashing.MurmurHash3.orderedHash(
+      group.items.flatMap(_.inputs).filter(!group.contains(_))
+        .flatMap(results(_).asSuccess.map(_.value._2))
+    )
 
-    val externalInputs = group.items.flatMap(_.inputs).filter(!group.contains(_)).toVector
+    val sideHashes = scala.util.hashing.MurmurHash3.orderedHash(
+      group.toIterator.map(_.sideHash)
+    )
 
-    val inputsHash =
-      externalInputs.map(results(_).map(_._2)).hashCode +
-      group.toIterator.map(_.sideHash).toVector.hashCode() +
-      classLoaderSig.hashCode()
+    val inputsHash = externalInputsHash + sideHashes + classLoaderSignHash
 
     terminal match{
       case Left(task) =>
diff --git a/core/src/mill/eval/Result.scala b/core/src/mill/eval/Result.scala
index 690c5d30..d0400599 100644
--- a/core/src/mill/eval/Result.scala
+++ b/core/src/mill/eval/Result.scala
@@ -2,14 +2,16 @@ package mill.eval
 
 sealed trait Result[+T]{
   def map[V](f: T => V): Result[V]
+  def asSuccess: Option[Result.Success[T]] = None
 }
 object Result{
   implicit def create[T](t: => T): Result[T] = {
     try Success(t)
     catch { case e: Throwable => Exception(e, new OuterStack(new java.lang.Exception().getStackTrace)) }
   }
-  case class Success[T](value: T) extends Result[T]{
+  case class Success[+T](value: T) extends Result[T]{
     def map[V](f: T => V) = Result.Success(f(value))
+    override def asSuccess = Some(this)
   }
   case object Skipped extends Result[Nothing]{
     def map[V](f: Nothing => V) = this
diff --git a/core/src/mill/util/Logger.scala b/core/src/mill/util/Logger.scala
index 55ea84cc..714b9add 100644
--- a/core/src/mill/util/Logger.scala
+++ b/core/src/mill/util/Logger.scala
@@ -136,7 +136,7 @@ case class FileLogger(colored: Boolean, file: Path) extends Logger {
   def info(s: String) = outputStream.println(s)
   def error(s: String) = outputStream.println(s)
   def ticker(s: String) = outputStream.println(s)
-  val inStream: InputStream = new ByteArrayInputStream(Array())
+  val inStream: InputStream = DummyInputStream
   override def close() = {
     if (outputStreamUsed)
       outputStream.close()