Only traverse directories in jar once

Author: nicolasstucki

compiler/src/dotty/tools/dotc/classpath/ZipAndJarFileLookupFactory.scala

@@ -50,8 +50,8 @@ object ZipAndJarClassPathFactory extends ZipAndJarFileLookupFactory {
     // This method is performance sensitive as it is used by SBT's ExtractDependencies phase.
     override def findClass(className: String): Option[ClassFileEntryImpl] = {
       val (pkg, simpleClassName) = PackageNameUtils.separatePkgAndClassNames(className)
-      file(PackageName(pkg), simpleClassName + ".tasty")
-        .orElse(file(PackageName(pkg), simpleClassName + ".class"))
+      val binaries = files(PackageName(pkg), simpleClassName + ".tasty", simpleClassName + ".class")
+      binaries.find(_.file.isTasty).orElse(binaries.find(_.file.isClass))
     }
 
     override private[dotty] def classes(inPackage: PackageName): Seq[ClassFileEntry] = files(inPackage)

compiler/src/dotty/tools/dotc/classpath/ZipArchiveFileLookup.scala

@@ -43,6 +43,15 @@ trait ZipArchiveFileLookup[FileEntryType <: ClassRepresentation] extends Efficie
     }
     yield createFileEntry(entry)
 
+  protected def files(inPackage: PackageName, names: String*): Seq[FileEntryType] =
+    for {
+      dirEntry <- findDirEntry(inPackage).toSeq
+      name <- names
+      entry <- Option(dirEntry.lookupName(name, directory = false))
+      if isRequiredFileType(entry)
+    }
+    yield createFileEntry(entry)
+
   protected def file(inPackage: PackageName, name: String): Option[FileEntryType] =
     for {
       dirEntry <- findDirEntry(inPackage)