class Jekyll::PathManager

A singleton class that caches frozen instances of path strings returned from its methods.

NOTE:

This class exists because `File.join` allocates an Array and returns a new String on every
call using **the same arguments**. Caching the result means reduced memory usage.
However, the caches are never flushed so that they can be used even when a site is
regenerating. The results are frozen to deter mutation of the cached string.

Therefore, employ this class only for situations where caching the result is necessary
for performance reasons.

Public Class Methods

join(base, item) click to toggle source

Wraps ‘File.join` to cache the frozen result. Reassigns `nil`, empty strings and empty arrays to a frozen empty string beforehand.

Returns a frozen string.

# File lib/jekyll/path_manager.rb, line 24
def join(base, item)
  base = "" if base.nil? || base.empty?
  item = "" if item.nil? || item.empty?
  @join ||= {}
  @join[base] ||= {}
  @join[base][item] ||= File.join(base, item).freeze
end
sanitized_path(base_directory, questionable_path) click to toggle source

Ensures the questionable path is prefixed with the base directory and prepends the questionable path with the base directory if false.

Returns a frozen string.

# File lib/jekyll/path_manager.rb, line 36
def sanitized_path(base_directory, questionable_path)
  @sanitized_path ||= {}
  @sanitized_path[base_directory] ||= {}
  @sanitized_path[base_directory][questionable_path] ||= if questionable_path.nil?
                                                           base_directory.freeze
                                                         else
                                                           sanitize_and_join(
                                                             base_directory, questionable_path
                                                           ).freeze
                                                         end
end

Private Class Methods

sanitize_and_join(base_directory, questionable_path) click to toggle source
# File lib/jekyll/path_manager.rb, line 50
def sanitize_and_join(base_directory, questionable_path)
  clean_path = if questionable_path.start_with?("~")
                 questionable_path.dup.insert(0, "/")
               else
                 questionable_path
               end
  clean_path = File.expand_path(clean_path, "/")
  return clean_path if clean_path.eql?(base_directory)

  # remove any remaining extra leading slashes not stripped away by calling
  # `File.expand_path` above.
  clean_path.squeeze!("/")
  return clean_path if clean_path.start_with?(slashed_dir_cache(base_directory))

  clean_path.sub!(%r!\A\w:/!, "/")
  join(base_directory, clean_path)
end
slashed_dir_cache(base_directory) click to toggle source
# File lib/jekyll/path_manager.rb, line 68
def slashed_dir_cache(base_directory)
  @slashed_dir_cache ||= {}
  @slashed_dir_cache[base_directory] ||= base_directory.sub(%r!\z!, "/")
end