Sha256: fe20ca4af4db792962e237aa26bdf327dcea2d1a3caf24cf8bf1a7b46915257b

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Versions: 19

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Contents

require 'concurrent/map'

module Dry
  module Core
    # Allows you to cache call results that are solely determined by arguments.
    #
    # @example
    #   require 'dry/core/cache'
    #
    #   class Foo
    #     extend Dry::Core::Cache
    #
    #     def heavy_computation(arg1, arg2)
    #       fetch_or_store(arg1, arg2) { arg1 ^ arg2 }
    #     end
    #   end
    #
    # @api public
    module Cache
      # @api private
      def self.extended(klass)
        super
        klass.include(Methods)
        klass.instance_variable_set(:@__cache__, Concurrent::Map.new)
      end

      # @api private
      def inherited(klass)
        super
        klass.instance_variable_set(:@__cache__, cache)
      end

      # @api private
      def cache
        @__cache__
      end

      # Caches a result of the block evaluation
      #
      # @param [Array<Object>] args List of hashable objects
      # @yield An arbitrary block
      #
      # @note beware Proc instance hashes are not equal, i.e. -> { 1 }.hash != -> { 1 }.hash,
      #       this means you shouldn't pass Procs in args unless you're sure
      #       they are always the same instances, otherwise you introduce a memory leak
      #
      # @return [Object] block's return value (cached for subsequent calls with the same argument values)
      def fetch_or_store(*args, &block)
        cache.fetch_or_store(args.hash, &block)
      end

      # Instance methods
      module Methods
        # Delegates call to the class-level method
        #
        # @param [Array<Object>] args List of hashable objects
        # @yield An arbitrary block
        #
        # @return [Object] block's return value
        def fetch_or_store(*args, &block)
          self.class.fetch_or_store(*args, &block)
        end
      end
    end
  end
end

Version data entries

19 entries across 19 versions & 1 rubygems

Version Path
dry-core-0.4.7 lib/dry/core/cache.rb
dry-core-0.4.6 lib/dry/core/cache.rb
dry-core-0.4.5 lib/dry/core/cache.rb
dry-core-0.4.4 lib/dry/core/cache.rb
dry-core-0.4.3 lib/dry/core/cache.rb
dry-core-0.4.2 lib/dry/core/cache.rb
dry-core-0.4.1 lib/dry/core/cache.rb
dry-core-0.4.0 lib/dry/core/cache.rb
dry-core-0.3.4 lib/dry/core/cache.rb
dry-core-0.3.3 lib/dry/core/cache.rb
dry-core-0.3.2 lib/dry/core/cache.rb
dry-core-0.3.1 lib/dry/core/cache.rb
dry-core-0.3.0 lib/dry/core/cache.rb
dry-core-0.2.4 lib/dry/core/cache.rb
dry-core-0.2.3 lib/dry/core/cache.rb
dry-core-0.2.2 lib/dry/core/cache.rb
dry-core-0.2.1 lib/dry/core/cache.rb
dry-core-0.2.0 lib/dry/core/cache.rb
dry-core-0.1.0 lib/dry/core/cache.rb