Streamline pickling and unpickling of names

Author: odersky

compiler/src/dotty/tools/dotc/core/NameExtractors.scala

@@ -7,9 +7,12 @@ import StdNames._
 import util.DotClass
 import tasty.TastyFormat._
 import Decorators._
+import collection.mutable
 
 object NameExtractors {
 
+  private val extractors = new mutable.HashMap[Int, ClassifiedNameExtractor]
+
   abstract class NameInfo extends DotClass {
     def tag: Int
     def mkString(underlying: TermName): String
@@ -41,6 +44,7 @@ object NameExtractors {
       case DerivedTermName(underlying, `info`) => Some(underlying)
       case _ => None
     }
+    extractors(tag) = this
   }
 
   class PrefixNameExtractor(tag: Int, prefix: String, infoString: String) extends ClassifiedNameExtractor(tag, infoString) {
@@ -73,8 +77,8 @@ object NameExtractors {
   }
 
   object AnyQualifiedName {
-    def unapply(name: DerivedTermName): Option[(TermName, QualifiedNameExtractor # QualInfo)] = name match {
-      case DerivedTermName(qual, info: QualifiedNameExtractor # QualInfo) =>
+    def unapply(name: DerivedTermName): Option[(TermName, QualifiedInfo)] = name match {
+      case DerivedTermName(qual, info: QualifiedInfo) =>
         Some((name.underlying, info))
       case _ => None
     }
@@ -143,6 +147,8 @@ object NameExtractors {
 
   def definesNewName(tag: Int) = tag <= TraitSetterName.tag
 
+  def extractorOfTag(tag: Int) = extractors(tag)
+
   val separatorToQualified: Map[String, QualifiedNameExtractor] =
     Map("." -> QualifiedName,
       "$" -> FlattenedName,

compiler/src/dotty/tools/dotc/core/tasty/NameBuffer.scala

@@ -58,26 +58,18 @@ class NameBuffer extends TastyBuffer(10000) {
           else Codec.toUTF8(chrs, name.start, name.length)
         writeNat(bytes.length)
         writeBytes(bytes, bytes.length)
-      case QualifiedName(qualified, selector) =>
-        withLength { writeNameRef(qualified); writeNameRef(selector) }
-      case FlattenedName(qualified, selector) =>
-        withLength { writeNameRef(qualified); writeNameRef(selector) }
-      case ExpandedName(prefix, original) =>
-        withLength { writeNameRef(prefix); writeNameRef(original) }
+      case AnyQualifiedName(prefix, info) =>
+        withLength { writeNameRef(prefix); writeNameRef(info.name) }
       case SignedName(original, Signature(params, result)) =>
         withLength(
           { writeNameRef(original); writeNameRef(result); params.foreach(writeNameRef) },
           if ((params.length + 2) * maxIndexWidth <= maxNumInByte) 1 else 2)
-      case ModuleClassName(module) =>
-        withLength { writeNameRef(module) }
-      case SuperAccessorName(accessed) =>
-        withLength { writeNameRef(accessed) }
       case DefaultGetterName(method, paramNumber) =>
         withLength { writeNameRef(method); writeNat(paramNumber) }
-      case ShadowedName(original) =>
-        withLength { writeNameRef(original) }
       case VariantName(original, sign) =>
         withLength { writeNameRef(original); writeNat(sign + 1) }
+      case DerivedTermName(original, info) =>
+        withLength { writeNameRef(original) }
     }
   }
 

compiler/src/dotty/tools/dotc/core/tasty/TastyUnpickler.scala

@@ -55,23 +55,19 @@ class TastyUnpickler(reader: TastyReader) {
         FlattenedName(readName(), readName().asSimpleName)
       case EXPANDED =>
         ExpandedName(readName(), readName().asSimpleName)
+      case DEFAULTGETTER =>
+        DefaultGetterName(readName(), readNat())
+      case VARIANT =>
+        VariantName(readName(), readNat() - 1)
       case SIGNED =>
         val original = readName()
         val result = readName().toTypeName
         val params = until(end)(readName().toTypeName)
         var sig = Signature(params, result)
         if (sig == Signature.NotAMethod) sig = Signature.NotAMethod
         SignedName(original, sig)
-      case OBJECTCLASS =>
-        ModuleClassName(readName())
-      case SUPERACCESSOR =>
-        SuperAccessorName(readName())
-      case DEFAULTGETTER =>
-        DefaultGetterName(readName(), readNat())
-      case SHADOWED =>
-        ShadowedName(readName())
-      case VARIANT =>
-        VariantName(readName(), readNat() - 1)
+      case _ =>
+        extractorOfTag(tag)(readName())
     }
     assert(currentAddr == end, s"bad name $result $start $currentAddr $end")
     result