Improves performance of file.expand, file.expandMapping, and `tas…

…k.normalizeMultiTaskFiles` by caching glob fs results across multiple calls to `glob.sync`

lib/grunt/file.js

@@ -93,6 +93,8 @@ file.expand = function() {
  // If the first argument is an options object, save those options to pass
  // into the file.glob.sync method.
  var options = grunt.util.kindOf(args[0]) === 'object' ? args.shift() : {};
+ // Cache fs calls across multiple file.glob.sync operations
+ var globOptions = grunt.util._.extend(file._createGlobIoCache(), options);
  // Use the first argument if it's an Array, otherwise convert the arguments
  // object to an array and use that.
  var patterns = Array.isArray(args[0]) ? args[0] : args;
@@ -101,7 +103,7 @@ file.expand = function() {
  // Return all matching filepaths.
  var matches = processPatterns(patterns, function(pattern) {
  // Find all matching files for this pattern.
- return file.glob.sync(pattern, options);
+ return file.glob.sync(pattern, globOptions);
  });
  // Filter result set?
  if (options.filter) {
@@ -452,3 +454,14 @@ file.isPathInCwd = function() {
  return false;
  }
 };
+
+// Creates all glob options that store cached fs results for the `glob` library.
+// Can be removed when this glob PR is released: https://github.com/isaacs/node-glob/pull/306
+file._createGlobIoCache = function() {
+ return {
+ cache: Object.create(null),
+ statCache: Object.create(null),
+ symlinks: Object.create(null),
+ realpathCache: Object.create(null)
+ };
+};

lib/grunt/task.js

@@ -117,6 +117,7 @@ task.normalizeMultiTaskFiles = function(data, target) {
  }
 
  // Process all normalized file objects.
+ var globIoCache = grunt.file._createGlobIoCache();
  files = grunt.util._(files).chain().forEach(function(obj) {
  if (!('src' in obj) || !obj.src) { return; }
  // Normalize .src properties to flattened array.
@@ -127,7 +128,7 @@ task.normalizeMultiTaskFiles = function(data, target) {
  }
  }).map(function(obj) {
  // Build options object, removing unwanted properties.
- var expandOptions = grunt.util._.extend({}, obj);
+ var expandOptions = grunt.util._.extend({}, globIoCache, obj);
  delete expandOptions.src;
  delete expandOptions.dest;