class ActiveSupport::Cache::FileStore

def cleanup(options = nil)
  options = merged_options(options)
  each_key(options) do |key|
    entry = read_entry(key, options)
    delete_entry(key, options) if entry && entry.expired?
  end
end

def clear(options = nil)
  root_dirs = Dir.entries(cache_path).reject{|f| ['.', '..'].include?(f)}
  FileUtils.rm_r(root_dirs.collect{|f| File.join(cache_path, f)})
end

def decrement(name, amount = 1, options = nil)
  file_name = key_file_path(namespaced_key(name, options))
  lock_file(file_name) do
    options = merged_options(options)
    if num = read(name, options)
      num = num.to_i - amount
      write(name, num, options)
      num
    else
      nil
    end
  end
end

def delete_empty_directories(dir)
  return if dir == cache_path
  if Dir.entries(dir).reject{|f| ['.', '..'].include?(f)}.empty?
    File.delete(dir) rescue nil
    delete_empty_directories(File.dirname(dir))
  end
end

def delete_entry(key, options)
  file_name = key_file_path(key)
  if File.exist?(file_name)
    begin
      File.delete(file_name)
      delete_empty_directories(File.dirname(file_name))
      true
    rescue => e
      # Just in case the error was caused by another process deleting the file first.
      raise e if File.exist?(file_name)
      false
    end
  end
end

def delete_matched(matcher, options = nil)
  options = merged_options(options)
  instrument(:delete_matched, matcher.inspect) do
    matcher = key_matcher(matcher, options)
    search_dir(cache_path) do |path|
      key = file_path_key(path)
      delete_entry(key, options) if key.match(matcher)
    end
  end
end

def ensure_cache_path(path)
  FileUtils.makedirs(path) unless File.exist?(path)
end

def file_path_key(path)
  fname = path[cache_path.size, path.size].split(File::SEPARATOR, 4).last
  fname.gsub(UNESCAPE_FILENAME_CHARS){|match| $1.ord.to_s(16)}
end

def increment(name, amount = 1, options = nil)
  file_name = key_file_path(namespaced_key(name, options))
  lock_file(file_name) do
    options = merged_options(options)
    if num = read(name, options)
      num = num.to_i + amount
      write(name, num, options)
      num
    else
      nil
    end
  end
end

def initialize(cache_path, options = nil)
  super(options)
  @cache_path = cache_path
  extend Strategy::LocalCache
end

def key_file_path(key)
  fname = key.to_s.gsub(ESCAPE_FILENAME_CHARS){|match| "%#{match.ord.to_s(16).upcase}"}
  hash = Zlib.adler32(fname)
  hash, dir_1 = hash.divmod(0x1000)
  dir_2 = hash.modulo(0x1000)
  fname_paths = []
  # Make sure file name is < 255 characters so it doesn't exceed file system limits.
  if fname.size <= 255
    fname_paths << fname
  else
    while fname.size <= 255
      fname_path << fname[0, 255]
      fname = fname[255, -1]
    end
  end
  File.join(cache_path, DIR_FORMATTER % dir_1, DIR_FORMATTER % dir_2, *fname_paths)
end

def lock_file(file_name, &block) # :nodoc:
  if File.exist?(file_name)
    File.open(file_name, 'r') do |f|
      begin
        f.flock File::LOCK_EX
        yield
      ensure
        f.flock File::LOCK_UN
      end
    end
  else
    yield
  end
end

def read_entry(key, options)
  file_name = key_file_path(key)
  if File.exist?(file_name)
    entry = File.open(file_name) { |f| Marshal.load(f) }
    if entry && !entry.expired? && !entry.expires_in && !self.options[:expires_in]
      # Check for deprecated use of +:expires_in+ option from versions < 3.0
      deprecated_expires_in = options[:expires_in]
      if deprecated_expires_in
        ActiveSupport::Deprecation.warn('Setting :expires_in on read has been deprecated in favor of setting it on write.', caller)
        if entry.created_at + deprecated_expires_in.to_f <= Time.now.to_f
          delete_entry(key, options)
          entry = nil
        end
      end
    end
    entry
  end
rescue
  nil
end

def search_dir(dir, &callback)
  Dir.foreach(dir) do |d|
    next if d == "." || d == ".."
    name = File.join(dir, d)
    if File.directory?(name)
      search_dir(name, &callback)
    else
      callback.call name
    end
  end
end

def write_entry(key, entry, options)
  file_name = key_file_path(key)
  ensure_cache_path(File.dirname(file_name))
  File.atomic_write(file_name, cache_path) {|f| Marshal.dump(entry, f)}
  true
end