From 139ff44a692f6f35bed715528d38f95a14b8340e Mon Sep 17 00:00:00 2001
From: extempore <extempore@5e8d7ff9-d8ef-0310-90f0-a4852d11357a>
Date: Mon, 20 Jun 2011 16:08:45 +0000
Subject: [PATCH] Reverts r25085 ("Performance tweaks for AbstractFile, no
 review.") which apparently is making the IDE refuse to overwrite classfiles.
 For the life of me I can't find why there should be any difference. Bowing to
 expedience, no review.

git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@25117 5e8d7ff9-d8ef-0310-90f0-a4852d11357a
---
 .../scala/tools/nsc/io/AbstractFile.scala     | 62 +++++++++----------
 1 file changed, 29 insertions(+), 33 deletions(-)

diff --git a/src/compiler/scala/tools/nsc/io/AbstractFile.scala b/src/compiler/scala/tools/nsc/io/AbstractFile.scala
index af4d68e86..e95928ad6 100644
--- a/src/compiler/scala/tools/nsc/io/AbstractFile.scala
+++ b/src/compiler/scala/tools/nsc/io/AbstractFile.scala
@@ -9,8 +9,6 @@ package io
 
 import java.io.{ FileOutputStream, IOException, InputStream, OutputStream, BufferedOutputStream }
 import java.net.URL
-import PartialFunction._
-import java.io.File.{ separatorChar => separator }
 import scala.collection.mutable.ArrayBuffer
 
 /**
@@ -84,6 +82,7 @@ object AbstractFile {
  * </p>
  */
 abstract class AbstractFile extends AnyRef with Iterable[AbstractFile] {
+
   /** Returns the name of this abstract file. */
   def name: String
 
@@ -187,47 +186,43 @@ abstract class AbstractFile extends AnyRef with Iterable[AbstractFile] {
    *  @return          ...
    */
   def lookupPath(path: String, directory: Boolean): AbstractFile = {
-    lookupPathInternal(path, directory, false)
+    lookup((f, p, dir) => f.lookupName(p, dir), path, directory)
   }
 
   /** Return an abstract file that does not check that `path` denotes
    *  an existing file.
    */
   def lookupPathUnchecked(path: String, directory: Boolean): AbstractFile = {
-    lookupPathInternal(path, directory, true)
-  }
-  
-  private def lookupPathInternal(path0: String, directory: Boolean, unchecked: Boolean): AbstractFile = {
-    // trim trailing '/'s
-    val path = (
-      if (path0.charAt(path0.length - 1) != separator) path0
-      else path0.substring(0, path0.length - 1)
-    )    
-    def loop(file: AbstractFile, start: Int): AbstractFile = {
-      val index = path.indexOf(separator, start)
-      if (index < 0) {
-        if (unchecked) file.lookupNameUnchecked(path, directory)
-        else file.lookupName(path, directory)
-      }
-      else {
-        val name = path.substring(start, index)
-        val next = (
-          if (unchecked) file.lookupNameUnchecked(name, true)
-          else file.lookupName(name, true)
-        )
-        if (next == null) null
-        else loop(next, index + 1)
-      }
-    }
-    loop(this, 0)
+    lookup((f, p, dir) => f.lookupNameUnchecked(p, dir), path, directory)
   }
 
-  private def fileOrSubdirectoryNamed(name: String, directory: Boolean): AbstractFile = {
-    val lookup = lookupName(name, directory)
+  private def lookup(getFile: (AbstractFile, String, Boolean) => AbstractFile,
+                     path0: String,
+                     directory: Boolean): AbstractFile = {    
+    val separator = java.io.File.separatorChar
+    // trim trailing '/'s
+    val path: String = if (path0.last == separator) path0 dropRight 1 else path0
+    val length = path.length()
+    assert(length > 0 && !(path.last == separator), path)
+    var file = this
+    var start = 0
+    while (true) {
+      val index = path.indexOf(separator, start)
+      assert(index < 0 || start < index)
+      val name = path.substring(start, if (index < 0) length else index)
+      file = getFile(file, name, if (index < 0) directory else true)
+      if ((file eq null) || index < 0) return file
+      start = index + 1
+    }
+    file
+  }
+  
+  private def fileOrSubdirectoryNamed(name: String, isDir: Boolean): AbstractFile = {
+    val lookup = lookupName(name, isDir)
     if (lookup != null) lookup
     else {
       val jfile = new JFile(file, name)
-      if (directory) jfile.mkdirs() else jfile.createNewFile()
+      if (isDir) jfile.mkdirs() else jfile.createNewFile()
       new PlainFile(jfile)
     }
   }
@@ -254,5 +249,6 @@ abstract class AbstractFile extends AnyRef with Iterable[AbstractFile] {
   protected def unsupported(msg: String): Nothing = throw new UnsupportedOperationException(msg)
   
   /** Returns the path of this abstract file. */
-  override def toString = path
+  override def toString() = path
+
 }