Introduce custom serializers to ActiveJob arguments

activejob/CHANGELOG.md

@@ -1,3 +1,6 @@
+*   Add support to define custom argument serializers.
+
+    *Evgenii Pecherkin*, *Rafael Mendonça França*
 
 
 Please check [5-2-stable](https://github.com/rails/rails/blob/5-2-stable/activejob/CHANGELOG.md) for previous changes.

activejob/lib/active_job.rb

@@ -33,6 +33,7 @@ module ActiveJob
 
   autoload :Base
   autoload :QueueAdapters
+  autoload :Serializers
   autoload :ConfiguredJob
   autoload :TestCase
   autoload :TestHelper

activejob/lib/active_job/arguments.rb

@@ -44,13 +44,24 @@ def deserialize(arguments)
     end
 
     private
+
       # :nodoc:
       GLOBALID_KEY = "_aj_globalid".freeze
       # :nodoc:
       SYMBOL_KEYS_KEY = "_aj_symbol_keys".freeze
       # :nodoc:
       WITH_INDIFFERENT_ACCESS_KEY = "_aj_hash_with_indifferent_access".freeze
-      private_constant :GLOBALID_KEY, :SYMBOL_KEYS_KEY, :WITH_INDIFFERENT_ACCESS_KEY
+      # :nodoc:
+      OBJECT_SERIALIZER_KEY = "_aj_serialized"
+
+      # :nodoc:
+      RESERVED_KEYS = [
+        GLOBALID_KEY, GLOBALID_KEY.to_sym,
+        SYMBOL_KEYS_KEY, SYMBOL_KEYS_KEY.to_sym,
+        OBJECT_SERIALIZER_KEY, OBJECT_SERIALIZER_KEY.to_sym,
+        WITH_INDIFFERENT_ACCESS_KEY, WITH_INDIFFERENT_ACCESS_KEY.to_sym,
+      ]
+      private_constant :RESERVED_KEYS
 
       def serialize_argument(argument)
         case argument
@@ -70,7 +81,7 @@ def serialize_argument(argument)
           result[SYMBOL_KEYS_KEY] = symbol_keys
           result
         else
-          raise SerializationError.new("Unsupported argument type: #{argument.class.name}")
+          Serializers.serialize(argument)
         end
       end
 
@@ -85,6 +96,8 @@ def deserialize_argument(argument)
         when Hash
           if serialized_global_id?(argument)
             deserialize_global_id argument
+          elsif custom_serialized?(argument)
+            Serializers.deserialize(argument)
           else
             deserialize_hash(argument)
           end
@@ -101,6 +114,10 @@ def deserialize_global_id(hash)
         GlobalID::Locator.locate hash[GLOBALID_KEY]
       end
 
+      def custom_serialized?(hash)
+        hash.key?(OBJECT_SERIALIZER_KEY)
+      end
+
       def serialize_hash(argument)
         argument.each_with_object({}) do |(key, value), hash|
           hash[serialize_hash_key(key)] = serialize_argument(value)
@@ -117,14 +134,6 @@ def deserialize_hash(serialized_hash)
         result
       end
 
-      # :nodoc:
-      RESERVED_KEYS = [
-        GLOBALID_KEY, GLOBALID_KEY.to_sym,
-        SYMBOL_KEYS_KEY, SYMBOL_KEYS_KEY.to_sym,
-        WITH_INDIFFERENT_ACCESS_KEY, WITH_INDIFFERENT_ACCESS_KEY.to_sym,
-      ]
-      private_constant :RESERVED_KEYS
-
       def serialize_hash_key(key)
         case key
         when *RESERVED_KEYS

activejob/lib/active_job/base.rb

@@ -59,6 +59,7 @@ module ActiveJob #:nodoc:
   # * SerializationError - Error class for serialization errors.
   class Base
     include Core
+    include Serializers
     include QueueAdapter
     include QueueName
     include QueuePriority

activejob/lib/active_job/railtie.rb

@@ -7,11 +7,17 @@ module ActiveJob
   # = Active Job Railtie
   class Railtie < Rails::Railtie # :nodoc:
     config.active_job = ActiveSupport::OrderedOptions.new
+    config.active_job.custom_serializers = []
 
     initializer "active_job.logger" do
       ActiveSupport.on_load(:active_job) { self.logger = ::Rails.logger }
     end
 
+    initializer "active_job.custom_serializers" do |app|
+      custom_serializers = app.config.active_job.delete(:custom_serializers)
+      ActiveJob::Serializers.add_serializers custom_serializers
+    end
+
     initializer "active_job.set_configs" do |app|
       options = app.config.active_job
       options.queue_adapter ||= :async

activejob/lib/active_job/serializers.rb

@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+require "set"
+
+module ActiveJob
+  # The <tt>ActiveJob::Serializers</tt> module is used to store a list of known serializers
+  # and to add new ones. It also has helpers to serialize/deserialize objects
+  module Serializers
+    extend ActiveSupport::Autoload
+    extend ActiveSupport::Concern
+
+    autoload :ObjectSerializer
+    autoload :SymbolSerializer
+    autoload :DurationSerializer
+    autoload :DateSerializer
+    autoload :TimeSerializer
+    autoload :DateTimeSerializer
+
+    mattr_accessor :_additional_serializers
+    self._additional_serializers = Set.new
+
+    class << self
+      # Returns serialized representative of the passed object.
+      # Will look up through all known serializers.
+      # Raises `ActiveJob::SerializationError` if it can't find a proper serializer.
+      def serialize(argument)
+        serializer = serializers.detect { |s| s.serialize?(argument) }
+        raise SerializationError.new("Unsupported argument type: #{argument.class.name}") unless serializer
+        serializer.serialize(argument)
+      end
+
+      # Returns deserialized object.
+      # Will look up through all known serializers.
+      # If no serializers found will raise `ArgumentError`
+      def deserialize(argument)
+        serializer_name = argument[Arguments::OBJECT_SERIALIZER_KEY]
+        raise ArgumentError, "Serializer name is not present in the argument: #{argument.inspect}" unless serializer_name
+
+        serializer = serializer_name.safe_constantize
+        raise ArgumentError, "Serializer #{serializer_name} is not know" unless serializer
+
+        serializer.deserialize(argument)
+      end
+
+      # Returns list of known serializers
+      def serializers
+        self._additional_serializers
+      end
+
+      # Adds a new serializer to a list of known serializers
+      def add_serializers(*new_serializers)
+        self._additional_serializers += new_serializers
+      end
+    end
+
+    add_serializers SymbolSerializer,
+      DurationSerializer,
+      DateTimeSerializer,
+      DateSerializer,
+      TimeSerializer
+  end
+end

activejob/lib/active_job/serializers/date_serializer.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module ActiveJob
+  module Serializers
+    class DateSerializer < ObjectSerializer # :nodoc:
+      def serialize(date)
+        super("value" => date.iso8601)
+      end
+
+      def deserialize(hash)
+        Date.iso8601(hash["value"])
+      end
+
+      private
+
+        def klass
+          Date
+        end
+    end
+  end
+end

activejob/lib/active_job/serializers/date_time_serializer.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module ActiveJob
+  module Serializers
+    class DateTimeSerializer < ObjectSerializer # :nodoc:
+      def serialize(time)
+        super("value" => time.iso8601)
+      end
+
+      def deserialize(hash)
+        DateTime.iso8601(hash["value"])
+      end
+
+      private
+
+        def klass
+          DateTime
+        end
+    end
+  end
+end

activejob/lib/active_job/serializers/duration_serializer.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module ActiveJob
+  module Serializers
+    class DurationSerializer < ObjectSerializer # :nodoc:
+      def serialize(duration)
+        super("value" => duration.value, "parts" => Arguments.serialize(duration.parts))
+      end
+
+      def deserialize(hash)
+        value = hash["value"]
+        parts = Arguments.deserialize(hash["parts"])
+
+        klass.new(value, parts)
+      end
+
+      private
+
+        def klass
+          ActiveSupport::Duration
+        end
+    end
+  end
+end

activejob/lib/active_job/serializers/object_serializer.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+module ActiveJob
+  module Serializers
+    # Base class for serializing and deserializing custom times.
+    #
+    # Example
+    #
+    #     class MoneySerializer < ActiveJob::Serializers::ObjectSerializer
+    #       def serialize(money)
+    #         super("cents" => money.cents, "currency" => money.currency)
+    #       end
+    #
+    #       def deserialize(hash)
+    #         Money.new(hash["cents"], hash["currency"])
+    #       end
+    #
+    #       private
+    #
+    #         def klass
+    #           Money
+    #         end
+    #     end
+    class ObjectSerializer
+      include Singleton
+
+      class << self
+        delegate :serialize?, :serialize, :deserialize, to: :instance
+      end
+
+      # Determines if an argument should be serialized by a serializer.
+      def serialize?(argument)
+        argument.is_a?(klass)
+      end
+
+      # Serializes an argument to a JSON primitive type.
+      def serialize(hash)
+        { Arguments::OBJECT_SERIALIZER_KEY => self.class.name }.merge!(hash)
+      end
+
+      # Deserilizes an argument form a JSON primiteve type.
+      def deserialize(_argument)
+        raise NotImplementedError
+      end
+
+      protected
+
+        # The class of the object that will be serialized.
+        def klass
+          raise NotImplementedError
+        end
+    end
+  end
+end

activejob/lib/active_job/serializers/symbol_serializer.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module ActiveJob
+  module Serializers
+    class SymbolSerializer < ObjectSerializer # :nodoc:
+      def serialize(argument)
+        super("value" => argument.to_s)
+      end
+
+      def deserialize(argument)
+        argument["value"].to_sym
+      end
+
+      private
+
+        def klass
+          Symbol
+        end
+    end
+  end
+end

activejob/lib/active_job/serializers/time_serializer.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module ActiveJob
+  module Serializers
+    class TimeSerializer < ObjectSerializer # :nodoc:
+      def serialize(time)
+        super("value" => time.iso8601)
+      end
+
+      def deserialize(hash)
+        Time.iso8601(hash["value"])
+      end
+
+      private
+
+        def klass
+          Time
+        end
+    end
+  end
+end