[FileCache#find] N to 1 calls for regex matching

Signed-off-by: David Crosby <[email protected]>

lib/chef/file_cache.rb

@@ -159,9 +159,23 @@ def list
  # [String] - An array of file cache keys matching the glob
  def find(glob_pattern)
  keys = []
- Dir[File.join(Chef::Util::PathHelper.escape_glob_dir(file_cache_path), glob_pattern)].each do |f|
+ file_cache_dir = Chef::Util::PathHelper.escape_glob_dir(file_cache_path)
+ first_filename = Dir[file_cache_dir].first
+ return keys unless first_filename
+
+ # TODO: The usage of Regexp.escape and the match here is likely
+ # vestigial, but since it's only getting called once per method, the
+ # effort needed to confirm that its removal won't break something else
+ # isn't worth it. A task for a brave soul ;-)
+ regexp_pattern = /^(#{Regexp.escape(first_filename) + File::Separator}).+/
+
+ files = Dir[File.join(file_cache_dir, glob_pattern)]
+ until files.empty?
+ f = files.shift
  if File.file?(f)
- keys << f[/^#{Regexp.escape(Dir[Chef::Util::PathHelper.escape_glob_dir(file_cache_path)].first) + File::Separator}(.+)/, 1]
+ path_to_remove ||= f[regexp_pattern, 1]
+ f.delete_prefix!(path_to_remove)
+ keys << f
  end
  end
  keys