Merge pull request #483 from ashaffer/master

Consolidate common folders to avoid hitting the FSEvent limit

lib/fsevents-handler.js

@@ -12,6 +12,10 @@ try { fsevents = require('fsevents'); } catch (error) {}
 // (may be shared across chokidar FSWatcher instances)
 var FSEventsWatchers = Object.create(null);
 
+// Threshold of duplicate path prefixes at which to start
+// consolidating going forward
+var consolidateThreshhold = 10;
+
 // Private function: Instantiates the fsevents interface
 
 // * path       - string, path to be watched
@@ -34,6 +38,15 @@ function createFSEventsInstance(path, callback) {
 function setFSEventsListener(path, realPath, listener, rawEmitter) {
   var watchPath = sysPath.extname(path) ? sysPath.dirname(path) : path;
   var watchContainer;
+  var parentPath = sysPath.dirname(watchPath);
+
+  // If we've accumulated a substantial number of paths that
+  // could have been consolidated by watching one directory
+  // above the current one, create a watcher on the parent
+  // path instead, so that we do consolidate going forward.
+  if (couldConsolidate(parentPath)) {
+    watchPath = parentPath;
+  }
 
   var resolvedPath = sysPath.resolve(path);
   var hasSymlink = resolvedPath !== realPath;
@@ -89,6 +102,25 @@ function setFSEventsListener(path, realPath, listener, rawEmitter) {
   };
 }
 
+// Decide whether or not we should start a new higher-level
+// parent watcher
+function couldConsolidate(path) {
+  var keys = Object.keys(FSEventsWatchers);
+  var count = 0;
+
+  for (var i = 0, len = keys.length; i < len; ++i) {
+    var watchPath = keys[i];
+    if (watchPath.indexOf(path) === 0) {
+      count++;
+      if (count >= consolidateThreshhold) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
 // returns boolean indicating whether fsevents can be used
 function canUse() {
   return fsevents && Object.keys(FSEventsWatchers).length < 128;