Module: ActiveSupport::Cache

Includes:
ConnectionPoolLike
Defined in:
lib/active_support/cache.rb,
lib/active_support/cache/file_store.rb,
lib/active_support/cache/null_store.rb,
lib/active_support/cache/memory_store.rb,
lib/active_support/cache/mem_cache_store.rb,
lib/active_support/cache/redis_cache_store.rb,
lib/active_support/cache/strategy/local_cache.rb,
lib/active_support/cache/strategy/local_cache_middleware.rb

Overview

See ActiveSupport::Cache::Store for documentation.

Defined Under Namespace

Modules: ConnectionPoolLike, NullCoder, Strategy Classes: Entry, FileStore, MemCacheStore, MemoryStore, NullStore, RedisCacheStore, Store

Constant Summary collapse

UNIVERSAL_OPTIONS =

These options mean something to all cache implementations. Individual cache implementations may support additional options.

[:namespace, :compress, :compress_threshold, :expires_in, :race_condition_ttl, :coder]

Class Method Summary collapse

Methods included from ConnectionPoolLike

#with

Class Method Details

.expand_cache_key(key, namespace = nil) ⇒ Object

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.


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# File 'lib/active_support/cache.rb', line 89

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

.lookup_store(store = nil, *parameters) ⇒ Object

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

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# File 'lib/active_support/cache.rb', line 57

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