fs: improve performance for sync stat() functions

PR-URL: https://github.com/nodejs/node/pull/11522
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

1 files changed, 20 insertions, 6 deletions

diff --git a/lib/fs.js b/lib/fs.js
index d45bd82df70..3f2a3cc1ac4 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -131,7 +131,7 @@ function isFd(path) {
 }
 
 // Static method to set the stats properties on a Stats object.
-fs.Stats = function(
+function Stats(
     dev,
     mode,
     nlink,
@@ -160,7 +160,8 @@ fs.Stats = function(
   this.mtime = new Date(mtim_msec);
   this.ctime = new Date(ctim_msec);
   this.birthtime = new Date(birthtim_msec);
-};
+}
+fs.Stats = Stats;
 
 // Create a C++ binding to the function which creates a Stats object.
 binding.FSInitialize(fs.Stats);
@@ -262,7 +263,7 @@ fs.existsSync = function(path) {
   try {
     handleError((path = getPathFromURL(path)));
     nullCheck(path);
-    binding.stat(pathModule._makeLong(path));
+    binding.stat(pathModule._makeLong(path), statValues);
     return true;
   } catch (e) {
     return false;
@@ -856,20 +857,33 @@ fs.stat = function(path, callback) {
   binding.stat(pathModule._makeLong(path), req);
 };
 
+const statValues = new Float64Array(14);
+function statsFromValues() {
+  return new Stats(statValues[0], statValues[1], statValues[2], statValues[3],
+                   statValues[4], statValues[5],
+                   statValues[6] < 0 ? undefined : statValues[6], statValues[7],
+                   statValues[8], statValues[9] < 0 ? undefined : statValues[9],
+                   statValues[10], statValues[11], statValues[12],
+                   statValues[13]);
+}
+
 fs.fstatSync = function(fd) {
-  return binding.fstat(fd);
+  binding.fstat(fd, statValues);
+  return statsFromValues();
 };
 
 fs.lstatSync = function(path) {
   handleError((path = getPathFromURL(path)));
   nullCheck(path);
-  return binding.lstat(pathModule._makeLong(path));
+  binding.lstat(pathModule._makeLong(path), statValues);
+  return statsFromValues();
 };
 
 fs.statSync = function(path) {
   handleError((path = getPathFromURL(path)));
   nullCheck(path);
-  return binding.stat(pathModule._makeLong(path));
+  binding.stat(pathModule._makeLong(path), statValues);
+  return statsFromValues();
 };
 
 fs.readlink = function(path, options, callback) {