class ActiveSupport::Cache::FileStore
File Cache Store¶ ↑
A cache store implementation which stores everything on the filesystem.
Constants
- DIR_FORMATTER
- FILENAME_MAX_SIZE
- FILEPATH_MAX_SIZE
- GITKEEP_FILES
Attributes
Public Class Methods
ActiveSupport::Cache::Store::new
# File lib/active_support/cache/file_store.rb, line 20 def initialize(cache_path, **options) super(options) @cache_path = cache_path.to_s end
Advertise cache versioning support.
# File lib/active_support/cache/file_store.rb, line 26 def self.supports_cache_versioning? true end
Public Instance Methods
Preemptively iterates through all stored keys and removes the ones which have expired.
# File lib/active_support/cache/file_store.rb, line 40 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
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 33 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 a cached integer value. Returns the updated value.
If the key is unset, it will be set to -amount
.
cache.decrement("foo") # => -1
To set a specific value, call write
:
cache.write("baz", 5) cache.decrement("baz") # => 4
# File lib/active_support/cache/file_store.rb, line 75 def decrement(name, amount = 1, options = nil) modify_value(name, -amount, options) end
# File lib/active_support/cache/file_store.rb, line 79 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 a cached integer value. Returns the updated value.
If the key is unset, it starts from 0
:
cache.increment("foo") # => 1 cache.increment("bar", 100) # => 100
To set a specific value, call write
:
cache.write("baz", 5) cache.increment("baz") # => 6
# File lib/active_support/cache/file_store.rb, line 60 def increment(name, amount = 1, options = nil) modify_value(name, amount, options) end
Private Instance Methods
Delete empty directories in the cache.
# File lib/active_support/cache/file_store.rb, line 184 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
# File lib/active_support/cache/file_store.rb, line 120 def delete_entry(key, **options) if File.exist?(key) begin File.delete(key) delete_empty_directories(File.dirname(key)) true rescue # Just in case the error was caused by another process deleting the file first. raise if File.exist?(key) false end else false end end
Make sure a file path’s directories exist.
# File lib/active_support/cache/file_store.rb, line 193 def ensure_cache_path(path) FileUtils.makedirs(path) unless File.exist?(path) end
Translate a file path into a key.
# File lib/active_support/cache/file_store.rb, line 178 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 a file for a block so only one process can modify it at a time.
# File lib/active_support/cache/file_store.rb, line 137 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
Modifies the amount of an integer value that is stored in the cache. If the key is not found it is created and set to amount
.
# File lib/active_support/cache/file_store.rb, line 211 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 else write(name, Integer(amount), options) amount end end end
Translate a key into a file path.
ActiveSupport::Cache::Store#normalize_key
# File lib/active_support/cache/file_store.rb, line 151 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
# File lib/active_support/cache/file_store.rb, line 95 def read_entry(key, **options) if payload = read_serialized_entry(key, **options) entry = deserialize_entry(payload) entry if entry.is_a?(Cache::Entry) end end
# File lib/active_support/cache/file_store.rb, line 102 def read_serialized_entry(key, **) File.binread(key) if File.exist?(key) rescue => error logger.error("FileStoreError (#{error}): #{error.message}") if logger nil end
# File lib/active_support/cache/file_store.rb, line 197 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
# File lib/active_support/cache/file_store.rb, line 109 def write_entry(key, entry, **options) write_serialized_entry(key, serialize_entry(entry, **options), **options) end
# File lib/active_support/cache/file_store.rb, line 113 def write_serialized_entry(key, payload, **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(payload) } true end