Merge pull request #73 from jdantonio/actress

Actress merge

Author: jdantonio

Gemfile

@@ -2,6 +2,7 @@ source 'https://rubygems.org'
 
 gemspec
 
+
 group :development do
   gem 'rake', '~> 10.2.2'
   gem 'countloc', '~> 0.4.0', platforms: :mri

lib/concurrent.rb

@@ -28,6 +28,7 @@
 require 'concurrent/supervisor'
 require 'concurrent/timer_task'
 require 'concurrent/tvar'
+require 'concurrent/actress'
 
 # Modern concurrency tools for Ruby. Inspired by Erlang, Clojure, Scala, Haskell,
 # F#, C#, Java, and classic concurrency patterns.

lib/concurrent/actress.rb

@@ -0,0 +1,73 @@
+require 'concurrent/configuration'
+require 'concurrent/executor/one_by_one'
+require 'concurrent/ivar'
+require 'concurrent/logging'
+
+module Concurrent
+
+  # {include:file:lib/concurrent/actress/doc.md}
+  module Actress
+
+    require 'concurrent/actress/type_check'
+    require 'concurrent/actress/errors'
+    require 'concurrent/actress/core_delegations'
+    require 'concurrent/actress/envelope'
+    require 'concurrent/actress/reference'
+    require 'concurrent/actress/core'
+    require 'concurrent/actress/context'
+
+    require 'concurrent/actress/ad_hoc'
+
+    # @return [Reference, nil] current executing actor if any
+    def self.current
+      Thread.current[:__current_actress__]
+    end
+
+    # implements ROOT
+    class Root
+      include Context
+      # to allow spawning of new actors, spawn needs to be called inside the parent Actor
+      def on_message(message)
+        if message.is_a?(Array) && message.first == :spawn
+          spawn message[1], &message[2]
+        else
+          # ignore
+        end
+      end
+    end
+
+    # A root actor, a default parent of all actors spawned outside an actor
+    ROOT = Core.new(parent: nil, name: '/', class: Root).reference
+
+    # @param block for actress_class instantiation
+    # @param args see {.spawn_optionify}
+    def self.spawn(*args, &block)
+      if Actress.current
+        Core.new(spawn_optionify(*args).merge(parent: Actress.current), &block).reference
+      else
+        ROOT.ask([:spawn, spawn_optionify(*args), block]).value
+      end
+    end
+
+    # as {.spawn} but it'll raise when Actor not initialized properly
+    def self.spawn!(*args, &block)
+      spawn(spawn_optionify(*args).merge(initialized: ivar = IVar.new), &block).tap { ivar.no_error! }
+    end
+
+    # @overload spawn_optionify(actress_class, name, *args)
+    #   @param [Context] actress_class to be spawned
+    #   @param [String, Symbol] name of the instance, it's used to generate the path of the actor
+    #   @param args for actress_class instantiation
+    # @overload spawn_optionify(opts)
+    #   see {Core#initialize} opts
+    def self.spawn_optionify(*args)
+      if args.size == 1 && args.first.is_a?(Hash)
+        args.first
+      else
+        { class: args[0],
+          name:  args[1],
+          args:  args[2..-1] }
+      end
+    end
+  end
+end

lib/concurrent/actress/ad_hoc.rb

@@ -0,0 +1,14 @@
+module Concurrent
+  module Actress
+    class AdHoc
+      include Context
+      def initialize(*args, &initializer)
+        @on_message = Type! initializer.call(*args), Proc
+      end
+
+      def on_message(message)
+        instance_exec message, &@on_message
+      end
+    end
+  end
+end

lib/concurrent/actress/context.rb

@@ -0,0 +1,96 @@
+module Concurrent
+  module Actress
+
+    # module used to define actor behaviours
+    # @example ping
+    #  class Ping
+    #    include Context
+    #    def on_message(message)
+    #      message
+    #    end
+    #  end
+    #
+    #  Ping.spawn(:ping1).ask(:m).value #=> :m
+    module Context
+      include TypeCheck
+      include CoreDelegations
+
+      attr_reader :core
+
+      # @abstract override to define Actor's behaviour
+      # @param [Object] message
+      # @return [Object] a result which will be used to set the IVar supplied to Reference#ask
+      # @note self should not be returned (or sent to other actors), {#reference} should be used
+      #   instead
+      def on_message(message)
+        raise NotImplementedError
+      end
+
+      def logger
+        core.logger
+      end
+
+      # @api private
+      def on_envelope(envelope)
+        @envelope = envelope
+        on_message envelope.message
+      ensure
+        @envelope = nil
+      end
+
+      # @see Actress.spawn
+      def spawn(*args, &block)
+        Actress.spawn(*args, &block)
+      end
+
+      # @see Core#children
+      def children
+        core.children
+      end
+
+      # @see Core#terminate!
+      def terminate!
+        core.terminate!
+      end
+
+      private
+
+      # @api private
+      def initialize_core(core)
+        @core = Type! core, Core
+      end
+
+      # @return [Envelope] current envelope, accessible inside #on_message processing
+      def envelope
+        @envelope or raise 'envelope not set'
+      end
+
+      def self.included(base)
+        base.extend ClassMethods
+        super base
+      end
+
+      module ClassMethods
+        # behaves as {Actress.spawn} but class_name is omitted
+        def spawn(name_or_opts, *args, &block)
+          Actress.spawn spawn_optionify(name_or_opts, *args), &block
+        end
+
+        # behaves as {Actress.spawn!} but class_name is omitted
+        def spawn!(name_or_opts, *args, &block)
+          Actress.spawn! spawn_optionify(name_or_opts, *args), &block
+        end
+
+        private
+
+        def spawn_optionify(name_or_opts, *args)
+          if name_or_opts.is_a? Hash
+            name_or_opts.merge class: self
+          else
+            { class: self, name: name_or_opts, args: args }
+          end
+        end
+      end
+    end
+  end
+end