Attempt #1 to optimize findMember

Keeps fingerprints in scopes which are bitsets telling you what the last 6 bits of each hashcode of the names stored in the scope are. findMember will avoid looking in a scope if inferprints do not match.

1 files changed, 12 insertions, 3 deletions

diff --git a/src/reflect/scala/reflect/internal/Scopes.scala b/src/reflect/scala/reflect/internal/Scopes.scala
index ceacd2afb0..939cd556a6 100644
--- a/src/reflect/scala/reflect/internal/Scopes.scala
+++ b/src/reflect/scala/reflect/internal/Scopes.scala
@@ -42,6 +42,11 @@ trait Scopes extends api.Scopes { self: SymbolTable =>
    *  SynchronizedScope as mixin.
    */
   class Scope protected[Scopes] (initElems: ScopeEntry = null) extends Iterable[Symbol] {
+    
+    /** A bitset containing the last 6 bits of the start value of every name 
+     *  stored in this scope.
+     */
+    var fingerPrints: Long = 0L
 
     protected[Scopes] def this(base: Scope) = {
       this(base.elems)
@@ -95,7 +100,7 @@ trait Scopes extends api.Scopes { self: SymbolTable =>
      *
      *  @param e ...
      */
-    protected def enter(e: ScopeEntry) {
+    protected def enterEntry(e: ScopeEntry) {
       elemsCache = null
       if (hashtable ne null)
         enterInHash(e)
@@ -113,7 +118,11 @@ trait Scopes extends api.Scopes { self: SymbolTable =>
      *
      *  @param sym ...
      */
-    def enter[T <: Symbol](sym: T): T = { enter(newScopeEntry(sym, this)); sym }
+    def enter[T <: Symbol](sym: T): T = { 
+      fingerPrints |= (1L << sym.name.start)
+      enterEntry(newScopeEntry(sym, this)) 
+      sym 
+    }
 
     /** enter a symbol, asserting that no symbol with same name exists in scope
      *
@@ -344,7 +353,7 @@ trait Scopes extends api.Scopes { self: SymbolTable =>
   /** The empty scope (immutable).
    */
   object EmptyScope extends Scope {
-    override def enter(e: ScopeEntry) {
+    override def enterEntry(e: ScopeEntry) {
       abort("EmptyScope.enter")
     }
   }