From c2866d2393cce03486d7dfaedb0890c2166f9017 Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Tue, 27 Jul 2010 00:19:49 -0700
Subject: [PATCH] Make activate faster by avoiding extra work.

---
 lib/activate.js | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/lib/activate.js b/lib/activate.js
index 955d8a60839..610b9b027e3 100644
--- a/lib/activate.js
+++ b/lib/activate.js
@@ -71,8 +71,18 @@ function activate_ (arg, cb) {
           chain
             ( [lifecycle, data, "preactivate"]
             , [link, from, to]
-            , [shimIfExists, fromMain, toMain]
-            , [linkIfExists, fromLib, toLib]
+            , function (cb) {
+                fs.stat(toMain, function (er) {
+                  if (!er) return cb()
+                  shimIfExists(fromMain, toMain, cb)
+                })
+              }
+            , function (cb) {
+                fs.stat(toLib, function (er) {
+                  if (!er) return cb()
+                  linkIfExists(fromLib, toLib, cb)
+                })
+              }
             , [linkBins, data]
             , [lifecycle, data, "activate"]
             , [lifecycle, data, "postactivate"]
@@ -89,6 +99,11 @@ function linkBins (pkg, cb) {
   chain(Object.keys(pkg.bin).map(function (i) {
     var to = path.join(binroot, i)
       , from = to+"-"+pkg.version
-    return [link, from, to]
+    return function (cb) {
+      fs.stat(to, function (er) {
+        if (!er) cb()
+        linkIfExists(from, to, cb)
+      })
+    }
   }).concat(cb))
 }