From 375f09cd2685fe7b99b9b5334eb008241fa4185d Mon Sep 17 00:00:00 2001
From: Mark Harrah <dmharrah@gmail.com>
Date: Wed, 27 Apr 2011 20:40:52 -0400
Subject: [PATCH] speed up startup

---
 util/collection/Dag.scala      | 18 ++++++++++++++++++
 util/collection/PMap.scala     |  7 +++++++
 util/collection/Settings.scala | 10 ++++------
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/util/collection/Dag.scala b/util/collection/Dag.scala
index 29b43038a..8a6d0ba46 100644
--- a/util/collection/Dag.scala
+++ b/util/collection/Dag.scala
@@ -36,6 +36,24 @@ object Dag
 	
 		finished.toList;
 	}
+	// doesn't check for cycles
+	def topologicalSortUnchecked[T](node: T)(dependencies: T => Iterable[T]): List[T] =
+	{
+		val discovered = new mutable.HashSet[T]
+		var finished: List[T] = Nil
+
+		def visitAll(nodes: Iterable[T]) = nodes foreach visit
+		def visit(node : T){
+			if (!discovered(node)) {
+				discovered(node) = true; 
+				visitAll(dependencies(node))
+				finished ::= node;
+			}
+		}
+
+		visit(node);
+		finished;
+	}
 	final class Cyclic(val value: Any, val all: List[Any], val complete: Boolean)
 		extends Exception( "Cyclic reference involving " + (if(complete) all.mkString(", ") else value) )
 	{
diff --git a/util/collection/PMap.scala b/util/collection/PMap.scala
index 95bb1b6b0..febab0286 100644
--- a/util/collection/PMap.scala
+++ b/util/collection/PMap.scala
@@ -12,6 +12,8 @@ trait RMap[K[_], V[_]]
 	def get[T](k: K[T]): Option[V[T]]
 	def contains[T](k: K[T]): Boolean
 	def toSeq: Seq[(K[_], V[_])]
+	def keys: Iterable[K[_]]
+	def values: Iterable[V[_]]
 }
 
 trait IMap[K[_], V[_]] extends (K ~> V) with RMap[K,V]
@@ -54,6 +56,8 @@ object IMap
 		def mapValues[V2[_]](f: V ~> V2) =
 			new IMap0[K,V2](backing.mapValues(x => f(x)).toMap)
 		def toSeq = backing.toSeq
+		def keys = backing.keys
+		def values = backing.values
 
 		override def toString = backing.toString
 	}
@@ -83,6 +87,9 @@ class DelegatingPMap[K[_], V[_]](backing: mutable.Map[K[_], V[_]]) extends Abstr
 		v
 	}
 	def toSeq = backing.toSeq
+	def keys = backing.keys
+	def values = backing.values
+
 
 	private[this] def cast[T](v: V[_]): V[T] = v.asInstanceOf[V[T]]
 	private[this] def cast[T](o: Option[V[_]]): Option[V[T]] = o map cast[T]
diff --git a/util/collection/Settings.scala b/util/collection/Settings.scala
index aabb4c955..40d54de0d 100644
--- a/util/collection/Settings.scala
+++ b/util/collection/Settings.scala
@@ -68,7 +68,7 @@ trait Init[Scope]
 	def asTransform(s: Settings[Scope]): ScopedKey ~> Id = new (ScopedKey ~> Id) {
 		def apply[T](k: ScopedKey[T]): T = getValue(s, k)
 	}
-	def getValue[T](s: Settings[Scope], k: ScopedKey[T]) = s.get(k.scope, k.key).get
+	def getValue[T](s: Settings[Scope], k: ScopedKey[T]) = s.get(k.scope, k.key) getOrElse error("Internal settings error: invalid reference to " + display(k))
 	def asFunction[T](s: Settings[Scope]): ScopedKey[T] => T = k => getValue(s, k)
 
 	def compiled(init: Seq[Setting[_]], actual: Boolean = true)(implicit delegates: Scope => Seq[Scope], scopeLocal: ScopeLocal): CompiledMap =
@@ -124,18 +124,16 @@ trait Init[Scope]
 	}
 	private[this] def delegateForKey[T](sMap: ScopedMap, k: ScopedKey[T], scopes: Seq[Scope], refKey: ScopedKey[_], isFirst: Boolean): ScopedKey[T] = 
 	{
-		val scache = PMap.empty[ScopedKey, ScopedKey]
 		def resolve(search: Seq[Scope]): ScopedKey[T] =
 			search match {
 				case Seq() => throw Uninitialized(k, refKey)
 				case Seq(x, xs @ _*) =>
 					val sk = ScopedKey(x, k.key)
-					scache.getOrUpdate(sk, if(defines(sMap, sk, refKey, isFirst)) sk else resolve(xs))
+					val definesKey = (refKey != sk || !isFirst) && (sMap contains sk)
+					if(definesKey) sk else resolve(xs)
 			}
 		resolve(scopes)
 	}
-	private[this] def defines(map: ScopedMap, key: ScopedKey[_], refKey: ScopedKey[_], isFirst: Boolean): Boolean =
-		(map get key) match { case Some(Seq(x, _*)) => (refKey != key) || !isFirst; case _ => false }
 		
 	private[this] def applyInits(ordered: Seq[Compiled])(implicit delegates: Scope => Seq[Scope]): Settings[Scope] =
 		(empty /: ordered){ (m, comp) => comp.eval(m) }
@@ -149,7 +147,7 @@ trait Init[Scope]
 
 	final class Uninitialized(val key: ScopedKey[_], val refKey: ScopedKey[_], msg: String) extends Exception(msg)
 	def Uninitialized(key: ScopedKey[_], refKey: ScopedKey[_]): Uninitialized =
-		new Uninitialized(key, refKey, "Reference to uninitialized setting " + key.key.label + " (in " + key.scope + ") from " + refKey.key.label +" (in " + refKey.scope + ")")
+		new Uninitialized(key, refKey, "Reference to uninitialized setting " + display(key) + " from " + display(refKey))
 	final class Compiled(val key: ScopedKey[_], val dependencies: Iterable[ScopedKey[_]], val eval: Settings[Scope] => Settings[Scope])
 	{
 		override def toString = display(key)