Implement protocol plugin and rpcv2 protocol

gems/smithy-client/lib/smithy-client.rb

@@ -43,6 +43,10 @@
 require_relative 'smithy-client/cbor'
 require_relative 'smithy-client/codecs/cbor'
 
+# protocols
+require_relative 'smithy-client/protocols'
+require_relative 'smithy-client/protocols/rpc_v2'
+
 module Smithy
   # Base module for a generated Smithy gem.
   module Client

gems/smithy-client/lib/smithy-client/protocols.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+module Smithy
+  module Client
+    # TODO: Documentation
+    # All the generic protocols
+    module Protocols
+    end
+  end
+end

gems/smithy-client/lib/smithy-client/protocols/rpc_v2.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+module Smithy
+  module Client
+    module Protocols
+      # RPCV2 protocol
+      # TODO:
+      #  * Refactor methods to handle eventstreams
+      #  * Decide whether we should recognize query traits here
+      #  * Add Documentation
+      class RPCv2
+        SHAPE_ID = 'smithy.protocols#rpcv2Cbor'
+
+        def initialize(options = {})
+          @query_compatible = options[:query_compatible]
+        end
+
+        def build_request(context)
+          codec = Client::Codecs::CBOR.new(setting(context))
+          context.request.body = codec.serialize(context.params, context.operation.input)
+          context.request.http_method = 'POST'
+          apply_headers(context)
+        end
+
+        def parse_response(context)
+          output_shape = context.operation.output
+          codec = Client::Codecs::CBOR.new(setting(context))
+          codec.deserialize(context.response.body, output_shape, output_shape.type)
+        end
+
+        # TODO: Implement once errors are supported
+        def parse_error(_context, _response); end
+
+        private
+
+        def apply_headers(context)
+          context.request.headers['X-Amzn-Query-Mode'] = 'true' if query_compatible?(context)
+          context.request.headers['Smithy-Protocol'] = 'rpc-v2-cbor'
+          context.request.headers['Content-Type'] = 'application/cbor'
+          # TODO: Implement Content-Length Plugin/Handler
+          context.request.headers['Content-Length'] = context.request.body.size
+        end
+
+        def setting(context)
+          {}.tap do |h|
+            h[:query_compatible] = true if query_compatible?(context)
+          end
+        end
+
+        def query_compatible?(context)
+          @query_compatible ||
+            context.config.schema.service.traits.one? { |k, _v| k == 'aws.protocols#awsQuery' }
+        end
+      end
+    end
+  end
+end

gems/smithy/lib/smithy/generators/client.rb

@@ -82,6 +82,12 @@ def code_generated_plugins
             require_relative: true,
             source: Views::Client::EndpointPlugin.new(@plan).render
           )
+          e.yield "lib/#{@gem_name}/plugins/protocol.rb", Views::Client::Plugin.new(
+            class_name: "#{@plan.module_name}::Plugins::Protocol",
+            require_path: 'plugins/protocol',
+            require_relative: true,
+            source: Views::Client::ProtocolPlugin.new(@plan).render
+          )
         end
       end
 

gems/smithy/lib/smithy/templates/client/endpoint_provider_spec.erb

@@ -45,6 +45,8 @@ module <%= module_name %>
           <%= p.param %>: <%= p.value %>,
 <% end -%>
         )
+        # TODO: Revise once spec_helper is finalized
+        client.config.protocol = double(build_request: nil, parse_response: nil)
 <% if test_case.expect_error? -%>
         expect do
           client.<%= operation_input.operation_name %>(

gems/smithy/lib/smithy/templates/client/protocol_plugin.erb

@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+# This is generated code!
+
+module <%= module_name %>
+  module Plugins
+     # Protocol plugin - allows user to configure protocol on client.
+     # @api private
+     class Protocol < Smithy::Client::Plugin
+       option(
+         :protocol,
+<% if protocol -%>
+         doc_default: '<%= protocol %>',
+         doc_type: '<%= protocol %>',
+         docstring: <<~DOCS) do |_cfg|
+           Allows you to overwrite default protocol. The given protocol
+           must provide the following functionalities:
+           - `build_request`
+           - `parse_response`
+           - `parse_error`
+           See existing protocols within Smithy::Client::Protocols for examples.
+         DOCS
+         <%= protocol %>.new
+       end
+<% else -%>
+         default: nil,
+         docstring: <<~DOCS)
+           This configuration is required to build requests and parse responses.
+           In Smithy, a protocol is a named set of rules that defines the syntax
+           and semantics of how a client and server communicate. The given protocol
+           must provide the following functionalities:
+           - `build_request`
+           - `parse_response`
+           - `parse_error`
+           See existing protocols within Smithy::Client::Protocols for examples.
+         DOCS
+<% end -%>
+
+       # @api private
+       class Build < Smithy::Client::Handler
+         def call(context)
+           context.config.protocol.build_request(context)
+           @handler.call(context)
+         end
+       end
+
+       # @api private
+       class Parse < Smithy::Client::Handler
+         def call(context)
+           resp = @handler.call(context)
+           context.config.protocol.parse_response(context)
+           resp
+         end
+       end
+
+       # @api private
+       class Error < Smithy::Client::Handler
+         def call(context)
+           @handler.call(context).on(300..599) do |response|
+             context.config.protocol.parse_error(context, response)
+           end
+         end
+       end
+
+       def add_handlers(handlers, config)
+         handlers.add(Build)
+         handlers.add(Parse)
+         # TODO: Requires error handling to be implemented
+         # handlers.add(Error, step: :sign)
+       end
+     end
+  end
+end

gems/smithy/lib/smithy/views/client.rb

@@ -28,6 +28,7 @@ module Client; end
 require_relative 'client/gemspec'
 require_relative 'client/module'
 require_relative 'client/module_rbs'
+require_relative 'client/protocol_plugin'
 require_relative 'client/rubocop_yml'
 require_relative 'client/shapes'
 require_relative 'client/shapes_rbs'

gems/smithy/lib/smithy/views/client/client.rb

@@ -16,6 +16,10 @@ def module_name
           @plan.module_name
         end
 
+        def service_id
+          @plan.service.keys.first
+        end
+
         def gem_name
           @plan.gem_name
         end

gems/smithy/lib/smithy/views/client/protocol_plugin.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module Smithy
+  module Views
+    module Client
+      # @api private
+      class ProtocolPlugin < View
+        def initialize(plan)
+          @plan = plan
+          @model = plan.model
+          super()
+        end
+
+        attr_reader :plan
+
+        def module_name
+          @plan.module_name
+        end
+
+        def protocol
+          return if default_protocol.nil?
+
+          weld_protocols[default_protocol]
+        end
+
+        private
+
+        def service_traits
+          @service_traits ||= @plan.service.values.first['traits']
+        end
+
+        def weld_protocols
+          @weld_protocols ||= @plan.welds.map(&:protocols).reduce({}, :merge)
+        end
+
+        def default_protocol
+          return if weld_protocols.empty? && service_traits.nil?
+
+          weld_protocols.keys.find { |k| service_traits.key?(k) }
+        end
+      end
+    end
+  end
+end

gems/smithy/lib/smithy/weld.rb

@@ -62,5 +62,13 @@ def endpoint_function_bindings
     def plugins
       {}
     end
+
+    # Called to construct the protocol plugin. Any protocols defined here will be
+    # merged with other protocols. The key is the protocol trait ID and the value
+    # is the fully qualified class name of the protocol.
+    # @return [Hash<String, String>] protocols for use in protocol plugin.
+    def protocols
+      {}
+    end
   end
 end

gems/smithy/lib/smithy/welds.rb

@@ -2,6 +2,7 @@
 
 require_relative 'welds/endpoints'
 require_relative 'welds/plugins'
+require_relative 'welds/protocols'
 require_relative 'welds/rubocop'
 
 module Smithy

gems/smithy/lib/smithy/welds/protocols.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require 'smithy-client/protocols/rpc_v2'
+
+module Smithy
+  module Welds
+    # Provides map of protocol trait id and its Ruby class name.
+    # TODO: Update Welds to have a functionality to control ordering since there
+    #  is a priority ordered list of protocols and a requirement that SDK MUST
+    #  select the first entry in their priority ordered list that is also supported
+    #  by the service. Generic code generation MUST accept configuration of this priority
+    #  priority ordered list for use.
+    #  The priority order is as follows (within AWS context):
+    #  * Smithy RPCv2 CBOR
+    #  * AWS JSON 1.0
+    #  * AWS JSON 1.1
+    #  * REST JSON
+    #  * REST XML
+    #  * AWS/Query
+    #  * EC2/Query
+    class Protocols < Weld
+      def protocols
+        { 'smithy.protocols#rpcv2Cbor' => Smithy::Client::Protocols::RPCv2 }
+      end
+    end
+  end
+end

model/weather.smithy

@@ -2,7 +2,10 @@ $version: "2"
 
 namespace example.weather
 
+use smithy.protocols#rpcv2Cbor
+
 /// Provides weather forecasts.
+@rpcv2Cbor
 @paginated(inputToken: "nextToken", outputToken: "nextToken", pageSize: "pageSize")
 service Weather {
     version: "2006-03-01"

projections/weather/lib/weather/client.rb

@@ -3,6 +3,7 @@
 # This is generated code!
 
 require_relative 'plugins/endpoint'
+require_relative 'plugins/protocol'
 require 'smithy-client/plugins/logging'
 require 'smithy-client/plugins/raise_response_errors'
 require 'smithy-client/plugins/response_target'
@@ -15,6 +16,7 @@ class Client < Smithy::Client::Base
     self.schema = Shapes::SCHEMA
 
     add_plugin(Weather::Plugins::Endpoint)
+    add_plugin(Weather::Plugins::Protocol)
     add_plugin(Smithy::Client::Plugins::Logging)
     add_plugin(Smithy::Client::Plugins::RaiseResponseErrors)
     add_plugin(Smithy::Client::Plugins::ResponseTarget)
@@ -86,6 +88,13 @@ class Client < Smithy::Client::Base
     # @option options [Logger] :logger
     #  The Logger instance to send log messages to. If this option is not set,
     #  logging is disabled.
+    # @option options [Smithy::Client::Protocols::RPCv2] :protocol (Smithy::Client::Protocols::RPCv2)
+    #  Allows you to overwrite default protocol. The given protocol
+    #  must provide the following functionalities:
+    #  - `build_request`
+    #  - `parse_response`
+    #  - `parse_error`
+    #  See existing protocols within Smithy::Client::Protocols for examples.
     # @option options [Boolean] :raise_response_errors (true)
     #  When `true`, response errors are raised. When `false`, the error is placed on the
     #  output in the {Smithy::Client::Output#error error accessor}.

projections/weather/lib/weather/plugins/protocol.rb

@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+# This is generated code!
+
+module Weather
+  module Plugins
+    # Protocol plugin - allows user to configure protocol on client.
+    # @api private
+    class Protocol < Smithy::Client::Plugin
+      option(
+        :protocol,
+        doc_default: 'Smithy::Client::Protocols::RPCv2',
+        doc_type: 'Smithy::Client::Protocols::RPCv2',
+        docstring: <<~DOCS) do |_cfg|
+          Allows you to overwrite default protocol. The given protocol
+          must provide the following functionalities:
+          - `build_request`
+          - `parse_response`
+          - `parse_error`
+          See existing protocols within Smithy::Client::Protocols for examples.
+        DOCS
+        Smithy::Client::Protocols::RPCv2.new
+      end
+
+      # @api private
+      class Build < Smithy::Client::Handler
+        def call(context)
+          context.config.protocol.build_request(context)
+          @handler.call(context)
+        end
+      end
+
+      # @api private
+      class Parse < Smithy::Client::Handler
+        def call(context)
+          resp = @handler.call(context)
+          context.config.protocol.parse_response(context)
+          resp
+        end
+      end
+
+      # @api private
+      class Error < Smithy::Client::Handler
+        def call(context)
+          @handler.call(context).on(300..599) do |response|
+            context.config.protocol.parse_error(context, response)
+          end
+        end
+      end
+
+      def add_handlers(handlers, _config)
+        handlers.add(Build)
+        handlers.add(Parse)
+        # TODO: Requires error handling to be implemented
+        # handlers.add(Error, step: :sign)
+      end
+    end
+  end
+end

projections/weather/lib/weather/shapes.rb

@@ -61,7 +61,7 @@ module Shapes
       schema.service = ServiceShape.new(
         id: 'example.weather#Weather',
         version: '2006-03-01',
-        traits: { 'smithy.api#paginated' => { 'inputToken' => 'nextToken', 'outputToken' => 'nextToken', 'pageSize' => 'pageSize' } }
+        traits: { 'smithy.api#paginated' => { 'inputToken' => 'nextToken', 'outputToken' => 'nextToken', 'pageSize' => 'pageSize' }, 'smithy.protocols#rpcv2Cbor' => {} }
       )
       schema.add_operation(:get_city, OperationShape.new do |operation|
         operation.id = 'example.weather#GetCity'