fs: optimize realpath using uv_fs_realpath()

Remove realpath() and realpathSync() cache.
Use the native uv_fs_realpath() which is faster
then the JS implementation by a few orders of magnitude.

PR-URL: https://github.com/nodejs/node/pull/3594
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>

1 files changed, 2 insertions, 11 deletions

diff --git a/lib/module.js b/lib/module.js
index 8e5dc7a818..29a23776d7 100644
--- a/lib/module.js
+++ b/lib/module.js
@@ -108,19 +108,10 @@ function tryPackage(requestPath, exts) {
          tryExtensions(path.resolve(filename, 'index'), exts);
 }
 
-// In order to minimize unnecessary lstat() calls,
-// this cache is a list of known-real paths.
-// Set to an empty object to reset.
-Module._realpathCache = {};
-
 // check if the file exists and is not a directory
 function tryFile(requestPath) {
   const rc = stat(requestPath);
-  return rc === 0 && toRealPath(requestPath);
-}
-
-function toRealPath(requestPath) {
-  return fs.realpathSync(requestPath, Module._realpathCache);
+  return rc === 0 && fs.realpathSync(requestPath);
 }
 
 // given a path check a the file exists with any of the set extensions
@@ -163,7 +154,7 @@ Module._findPath = function(request, paths) {
     if (!trailingSlash) {
       const rc = stat(basePath);
       if (rc === 0) {  // File.
-        filename = toRealPath(basePath);
+        filename = fs.realpathSync(basePath);
       } else if (rc === 1) {  // Directory.
         if (exts === undefined)
           exts = Object.keys(Module._extensions);