class ActiveSupport::Cache::FileStore

A cache store implementation which stores everything on the filesystem.

FileStore implements the Strategy::LocalCache strategy which implements an in-memory cache inside of a block.

Constants

DIR_FORMATTER
FILENAME_MAX_SIZE
FILEPATH_MAX_SIZE
GITKEEP_FILES

Attributes

cache_path[R]

Public Class Methods

new(cache_path, **options) click to toggle source
Calls superclass method ActiveSupport::Cache::Store::new
# File lib/active_support/cache/file_store.rb, line 23
def initialize(cache_path, **options)
  super(options)
  @cache_path = cache_path.to_s
end
supports_cache_versioning?() click to toggle source

Advertise cache versioning support.

# File lib/active_support/cache/file_store.rb, line 29
def self.supports_cache_versioning?
  true
end

Public Instance Methods

cleanup(options = nil) click to toggle source

Preemptively iterates through all stored keys and removes the ones which have expired.

# File lib/active_support/cache/file_store.rb, line 43
def cleanup(options = nil)
  options = merged_options(options)
  search_dir(cache_path) do |fname|
    entry = read_entry(fname, **options)
    delete_entry(fname, **options) if entry && entry.expired?
  end
end
clear(options = nil) click to toggle source

Deletes all items from the cache. In this case it deletes all the entries in the specified file store directory except for .keep or .gitkeep. Be careful which directory is specified in your config file when using FileStore because everything in that directory will be deleted.

# File lib/active_support/cache/file_store.rb, line 36
def clear(options = nil)
  root_dirs = (Dir.children(cache_path) - GITKEEP_FILES)
  FileUtils.rm_r(root_dirs.collect { |f| File.join(cache_path, f) })
rescue Errno::ENOENT, Errno::ENOTEMPTY
end
decrement(name, amount = 1, options = nil) click to toggle source

Decrements an already existing integer value that is stored in the cache. If the key is not found nothing is done.

# File lib/active_support/cache/file_store.rb, line 59
def decrement(name, amount = 1, options = nil)
  modify_value(name, -amount, options)
end
delete_matched(matcher, options = nil) click to toggle source
# File lib/active_support/cache/file_store.rb, line 63
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(path, **options) if key.match(matcher)
    end
  end
end
increment(name, amount = 1, options = nil) click to toggle source

Increments an already existing integer value that is stored in the cache. If the key is not found nothing is done.

# File lib/active_support/cache/file_store.rb, line 53
def increment(name, amount = 1, options = nil)
  modify_value(name, amount, options)
end

Private Instance Methods

delete_empty_directories(dir) click to toggle source

Delete empty directories in the cache.

# File lib/active_support/cache/file_store.rb, line 154
def delete_empty_directories(dir)
  return if File.realpath(dir) == File.realpath(cache_path)
  if Dir.children(dir).empty?
    Dir.delete(dir) rescue nil
    delete_empty_directories(File.dirname(dir))
  end
end
delete_entry(key, **options) click to toggle source
# File lib/active_support/cache/file_store.rb, line 92
def delete_entry(key, **options)
  if File.exist?(key)
    begin
      File.delete(key)
      delete_empty_directories(File.dirname(key))
      true
    rescue => e
      # Just in case the error was caused by another process deleting the file first.
      raise e if File.exist?(key)
      false
    end
  end
end
ensure_cache_path(path) click to toggle source

Make sure a file path's directories exist.

# File lib/active_support/cache/file_store.rb, line 163
def ensure_cache_path(path)
  FileUtils.makedirs(path) unless File.exist?(path)
end
file_path_key(path) click to toggle source

Translate a file path into a key.

# File lib/active_support/cache/file_store.rb, line 148
def file_path_key(path)
  fname = path[cache_path.to_s.size..-1].split(File::SEPARATOR, 4).last
  URI.decode_www_form_component(fname, Encoding::UTF_8)
end
lock_file(file_name) { || ... } click to toggle source

Lock a file for a block so only one process can modify it at a time.

# File lib/active_support/cache/file_store.rb, line 107
def lock_file(file_name, &block)
  if File.exist?(file_name)
    File.open(file_name, "r+") do |f|
      f.flock File::LOCK_EX
      yield
    ensure
      f.flock File::LOCK_UN
    end
  else
    yield
  end
end
modify_value(name, amount, options) click to toggle source

Modifies the amount of an already existing integer value that is stored in the cache. If the key is not found nothing is done.

# File lib/active_support/cache/file_store.rb, line 181
def modify_value(name, amount, options)
  file_name = normalize_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
    end
  end
end
normalize_key(key, options) click to toggle source

Translate a key into a file path.

# File lib/active_support/cache/file_store.rb, line 121
def normalize_key(key, options)
  key = super
  fname = URI.encode_www_form_component(key)

  if fname.size > FILEPATH_MAX_SIZE
    fname = ActiveSupport::Digest.hexdigest(key)
  end

  hash = Zlib.adler32(fname)
  hash, dir_1 = hash.divmod(0x1000)
  dir_2 = hash.modulo(0x1000)

  # Make sure file name doesn't exceed file system limits.
  if fname.length < FILENAME_MAX_SIZE
    fname_paths = fname
  else
    fname_paths = []
    begin
      fname_paths << fname[0, FILENAME_MAX_SIZE]
      fname = fname[FILENAME_MAX_SIZE..-1]
    end until fname.blank?
  end

  File.join(cache_path, DIR_FORMATTER % dir_1, DIR_FORMATTER % dir_2, fname_paths)
end
read_entry(key, **options) click to toggle source
# File lib/active_support/cache/file_store.rb, line 75
def read_entry(key, **options)
  if File.exist?(key)
    entry = File.open(key) { |f| deserialize_entry(f.read) }
    entry if entry.is_a?(Cache::Entry)
  end
rescue => e
  logger.error("FileStoreError (#{e}): #{e.message}") if logger
  nil
end
search_dir(dir, &callback) click to toggle source
# File lib/active_support/cache/file_store.rb, line 167
def search_dir(dir, &callback)
  return if !File.exist?(dir)
  Dir.each_child(dir) do |d|
    name = File.join(dir, d)
    if File.directory?(name)
      search_dir(name, &callback)
    else
      callback.call name
    end
  end
end
write_entry(key, entry, **options) click to toggle source
# File lib/active_support/cache/file_store.rb, line 85
def write_entry(key, entry, **options)
  return false if options[:unless_exist] && File.exist?(key)
  ensure_cache_path(File.dirname(key))
  File.atomic_write(key, cache_path) { |f| f.write(serialize_entry(entry)) }
  true
end