class ActiveSupport::CachingKeyGenerator 
        Caching Key Generator
CachingKeyGenerator is a wrapper around KeyGenerator which allows users to avoid re-executing the key generation process when it’s called using the same salt and key_size.
Public class methods
Source code GitHub
# File activesupport/lib/active_support/key_generator.rb, line 56
def initialize(key_generator)
  @key_generator = key_generator
  @cache_keys = Concurrent::Map.new
end
            Public instance methods
Returns a derived key suitable for use.
Source code GitHub
# File activesupport/lib/active_support/key_generator.rb, line 62
def generate_key(*args)
  @cache_keys[args.join("|")] ||= @key_generator.generate_key(*args)
end