ActiveSupport::Cache

See ActiveSupport::Cache::Store for documentation.

Namespace

Module

Class

Methods

expand_cache_key
lookup_store

Constants

DEFAULT_COMPRESS_LIMIT	=	1.kilobyte
DeserializationError	=	Class.new(StandardError)
	Raised by coders when the cache entry can’t be deserialized. This error is treated as a cache miss.
OPTION_ALIASES	=	{ expires_in: [:expire_in, :expired_in] }.freeze
	Mapping of canonical option names to aliases that a store will recognize.
UNIVERSAL_OPTIONS	=	[ :coder, :compress, :compress_threshold, :compressor, :expire_in, :expired_in, :expires_in, :namespace, :race_condition_ttl, :serializer, :skip_nil, ]
	These options mean something to all cache implementations. Individual cache implementations may support additional options.

Attributes

[RW]

format_version

Class Public methods

expand_cache_key(key, namespace = nil)

Expands out the key argument into a key that can be used for the cache store. Optionally accepts a namespace, and all keys will be scoped within that namespace.

If the key argument provided is an array, or responds to to_a, then each of elements in the array will be turned into parameters/keys and concatenated into a single key. For example:

ActiveSupport::Cache.expand_cache_key([:foo, :bar])               # => "foo/bar"
ActiveSupport::Cache.expand_cache_key([:foo, :bar], "namespace")  # => "namespace/foo/bar"

The key argument can also respond to cache_key or to_param.

📝 Source code

# File activesupport/lib/active_support/cache.rb, line 117
      def expand_cache_key(key, namespace = nil)
        expanded_cache_key = namespace ? +"#{namespace}/" : +""

        if prefix = ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]
          expanded_cache_key << "#{prefix}/"
        end

        expanded_cache_key << retrieve_cache_key(key)
        expanded_cache_key
      end

🔎 See on GitHub

lookup_store(store = nil, *parameters)

Creates a new Store object according to the given options.

If no arguments are passed to this method, then a new ActiveSupport::Cache::MemoryStore object will be returned.

If you pass a Symbol as the first argument, then a corresponding cache store class under the ActiveSupport::Cache namespace will be created. For example:

ActiveSupport::Cache.lookup_store(:memory_store)
# => returns a new ActiveSupport::Cache::MemoryStore object

ActiveSupport::Cache.lookup_store(:mem_cache_store)
# => returns a new ActiveSupport::Cache::MemCacheStore object

Any additional arguments will be passed to the corresponding cache store class’s constructor:

ActiveSupport::Cache.lookup_store(:file_store, '/tmp/cache')
# => same as: ActiveSupport::Cache::FileStore.new('/tmp/cache')

If the first argument is not a Symbol, then it will simply be returned:

ActiveSupport::Cache.lookup_store(MyOwnCacheStore.new)
# => returns MyOwnCacheStore.new

📝 Source code

# File activesupport/lib/active_support/cache.rb, line 85
      def lookup_store(store = nil, *parameters)
        case store
        when Symbol
          options = parameters.extract_options!
          # clean this up once Ruby 2.7 support is dropped
          # see https://github.com/rails/rails/pull/41522#discussion_r581186602
          if options.empty?
            retrieve_store_class(store).new(*parameters)
          else
            retrieve_store_class(store).new(*parameters, **options)
          end
        when Array
          lookup_store(*store)
        when nil
          ActiveSupport::Cache::MemoryStore.new
        else
          store
        end
      end

🔎 See on GitHub