fs: improve performance of all stat functions

By building the fs.Stats object in JS, which is returned by all fs stat
functions, calls to v8::Object::Set() are removed. This also includes
creating all associated Date objects in JS, rather than using
v8::Date::New(). Both these changes have significant performance gains.

Note that the returned value from fs.stat changes slightly for non-POSIX
systems. Whereas before the stats object would be missing blocks and
blksize keys, it now has these keys with undefined as the value.

Signed-off-by: Trevor Norris <trev.norris@gmail.com>

1 files changed, 32 insertions, 1 deletions

diff --git a/lib/fs.js b/lib/fs.js
index 4fc1314c8..129d4ee19 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -117,7 +117,38 @@ function nullCheck(path, callback) {
   return true;
 }
 
-fs.Stats = binding.Stats;
+// Static method to set the stats properties on a Stats object.
+fs.Stats = function(
+    dev,
+    mode,
+    nlink,
+    uid,
+    gid,
+    rdev,
+    ino,
+    size,
+    blocks,
+    atim_msec,
+    mtim_msec,
+    ctim_msec,
+    birthtim_msec) {
+  this.dev = dev;
+  this.mode = mode;
+  this.nlink = nlink;
+  this.uid = uid;
+  this.gid = gid;
+  this.rdev = rdev;
+  this.ino = ino;
+  this.size = size;
+  this.blocks = blocks;
+  this.atime = new Date(atim_msec);
+  this.mtime = new Date(mtim_msec);
+  this.ctime = new Date(ctim_msec);
+  this.birthtime = new Date(birthtim_msec);
+};
+
+// Create a C++ binding to the function which creates a Stats object.
+binding.FSInitialize(fs.Stats);
 
 fs.Stats.prototype._checkModeProperty = function(property) {
   return ((this.mode & constants.S_IFMT) === property);