A wrapper around the fs module that is persistent in the face of EMFILE errors.

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/utils/graceful-fs.js b/lib/utils/graceful-fs.js
new file mode 100644
index 000000000..0baa2576a
--- /dev/null
+++ b/lib/utils/graceful-fs.js
@@ -0,0 +1,31 @@
+
+// wrapper around the non-sync fs functions to gracefully handle
+// having too many file descriptors open.  Note that this is
+// *only* possible because async patterns let one interject timeouts
+// and other cleverness anywhere in the process without disrupting
+// anything else.
+var fs = require("fs")
+Object.keys(fs)
+  .forEach(function (i) {
+    exports[i] = (typeof fs[i] !== "function") ? fs[i]
+               : (i.match(/^[A-Z]|^create|Sync$/)) ? function () {
+                   return fs[i].apply(fs, arguments)
+                 }
+               : graceful(fs[i])
+  })
+
+
+function graceful (fn) { return function GRACEFUL () {
+  var args = Array.prototype.slice.call(arguments)
+    , cb_ = args.pop()
+  args.push(cb)
+  function cb (er) {
+    if (er && er.message.match(/^EMFILE, Too many open files/)) {
+      return setTimeout(function () {
+        GRACEFUL.apply(fs, args)
+      })
+    }
+    cb_.apply(null, arguments)
+  }
+  fn.apply(fs, args)
+}}