fs: avoid recompilation of closure

PR-URL: https://github.com/nodejs/node/pull/10789
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

lib/fs.js

@@ -1527,21 +1527,16 @@ fs.realpathSync = function realpathSync(p, options) {
   // the partial path scanned in the previous round, with slash
   var previous;
 
-  start();
+  // Skip over roots
+  var m = splitRootRe.exec(p);
+  pos = m[0].length;
+  current = m[0];
+  base = m[0];
 
-  function start() {
+  // On windows, check that the root exists. On unix there is no need.
-    // Skip over roots
+  if (isWindows && !knownHard[base]) {
-    var m = splitRootRe.exec(p);
+    fs.lstatSync(base);
-    pos = m[0].length;
+    knownHard[base] = true;
-    current = m[0];
-    base = m[0];
-    previous = '';
-
-    // On windows, check that the root exists. On unix there is no need.
-    if (isWindows && !knownHard[base]) {
-      fs.lstatSync(base);
-      knownHard[base] = true;
-    }
   }
 
   // walk down the path, swapping out linked pathparts for their real
@@ -1595,7 +1590,18 @@ fs.realpathSync = function realpathSync(p, options) {
 
     // resolve the link, then start over
     p = pathModule.resolve(resolvedLink, p.slice(pos));
-    start();
+
+    // Skip over roots
+    m = splitRootRe.exec(p);
+    pos = m[0].length;
+    current = m[0];
+    base = m[0];
+
+    // On windows, check that the root exists. On unix there is no need.
+    if (isWindows && !knownHard[base]) {
+      fs.lstatSync(base);
+      knownHard[base] = true;
+    }
   }
 
   if (cache) cache.set(original, p);
@@ -1626,26 +1632,21 @@ fs.realpath = function realpath(p, options, callback) {
   // the partial path scanned in the previous round, with slash
   var previous;
 
-  start();
+  var m = splitRootRe.exec(p);
-
+  pos = m[0].length;
-  function start() {
+  current = m[0];
-    // Skip over roots
+  base = m[0];
-    var m = splitRootRe.exec(p);
+  previous = '';
-    pos = m[0].length;
-    current = m[0];
-    base = m[0];
-    previous = '';
 
-    // On windows, check that the root exists. On unix there is no need.
+  // On windows, check that the root exists. On unix there is no need.
-    if (isWindows && !knownHard[base]) {
+  if (isWindows && !knownHard[base]) {
-      fs.lstat(base, function(err) {
+    fs.lstat(base, function(err) {
-        if (err) return callback(err);
+      if (err) return callback(err);
-        knownHard[base] = true;
+      knownHard[base] = true;
-        LOOP();
+      LOOP();
-      });
+    });
-    } else {
+  } else {
-      process.nextTick(LOOP);
+    process.nextTick(LOOP);
-    }
   }
 
   // walk down the path, swapping out linked pathparts for their real
@@ -1711,7 +1712,22 @@ fs.realpath = function realpath(p, options, callback) {
   function gotResolvedLink(resolvedLink) {
     // resolve the link, then start over
     p = pathModule.resolve(resolvedLink, p.slice(pos));
-    start();
+    var m = splitRootRe.exec(p);
+    pos = m[0].length;
+    current = m[0];
+    base = m[0];
+    previous = '';
+
+    // On windows, check that the root exists. On unix there is no need.
+    if (isWindows && !knownHard[base]) {
+      fs.lstat(base, function(err) {
+        if (err) return callback(err);
+        knownHard[base] = true;
+        LOOP();
+      });
+    } else {
+      process.nextTick(LOOP);
+    }
   }
 };