mojom: Add associative arrays to the mojom language.

mojo/public/tools/bindings/generators/cpp_templates/interface_definition.tmpl

 {%- import "interface_macros.tmpl" as interface_macros %}
 {%- set class_name = interface.name %}
 {%- set proxy_name = interface.name ~ "Proxy" %}
 {%- set namespace_as_string = "%s"|format(namespace|replace(".","::")) %}
 
 {%- macro alloc_params(parameters) %}
 {%-   for param in parameters %}
-{%-     if param.kind|is_object_kind  %}
+{%-     if param.kind|is_map_kind  %}
+mojo::Array<{{param.kind.key_kind|cpp_result_type}}> p{{loop.index}}_keys;
+Deserialize_(params->{{param.name}}_keys.ptr, &p{{loop.index}}_keys);
+mojo::Array<{{param.kind.value_kind|cpp_result_type}}> p{{loop.index}}_values;
+Deserialize_(params->{{param.name}}_values.ptr, &p{{loop.index}}_values);
+{{param.kind|cpp_result_type}} p{{loop.index}}(p{{loop.index}}_keys.Pass(),
+                                               p{{loop.index}}_values.Pass());
+{%-     elif param.kind|is_object_kind  %}
 {{param.kind|cpp_result_type}} p{{loop.index}};
 Deserialize_(params->{{param.name}}.ptr, &p{{loop.index}});
 {%      endif -%}
 {%-   endfor %}
 {%- endmacro %}
 
 {%- macro pass_params(parameters) %}
 {%-   for param in parameters %}
 {%-     if param.kind|is_string_kind -%}
 p{{loop.index}}
 {%-     elif param.kind|is_object_kind -%}
 p{{loop.index}}.Pass()
 {%-     elif param.kind|is_interface_kind -%}
 mojo::MakeProxy<{{param.kind|get_name_for_kind}}>(mojo::MakeScopedHandle(mojo::internal::FetchAndReset(&params->{{param.name}})))
 {%-     elif param.kind|is_interface_request_kind -%}
 mojo::MakeRequest<{{param.kind.kind|get_name_for_kind}}>(mojo::MakeScopedHandle(mojo::internal::FetchAndReset(&params->{{param.name}})))
 {%-     elif param.kind|is_any_handle_kind -%}
 mojo::MakeScopedHandle(mojo::internal::FetchAndReset(&params->{{param.name}}))
 {%-     elif param.kind|is_enum_kind -%}
 static_cast<{{param.kind|cpp_wrapper_type}}>(params->{{param.name}})
 {%-     else -%}
 params->{{param.name}}
 {%-     endif -%}
 {%-     if not loop.last %}, {% endif %}
 {%-   endfor %}
 {%- endmacro %}
 
+{%- macro mapping_prelude(parameters) -%}
+{%-   for param in parameters %}
+{%-     if param.kind|is_map_kind  %}
+  mojo::Array<{{param.kind.key_kind|cpp_result_type}}> in_{{param.name}}_keys;
+  mojo::Array<{{param.kind.value_kind|cpp_result_type}}> in_{{param.name}}_values;
+  in_{{param.name}}.DecomposeMapTo(&in_{{param.name}}_keys,
+                                   &in_{{param.name}}_values);
+{%-     endif -%}
+{%-   endfor -%}
+{%- endmacro %}
+
+
 {%- macro compute_payload_size(params_name, parameters) -%}
   size_t payload_size =
       mojo::internal::Align(sizeof({{params_name}}));
 {#--- Computes #}
 {%-   for param in parameters %}
-{%-     if param.kind|is_object_kind %}
+{%-     if param.kind|is_map_kind %}
+  payload_size += GetSerializedSize_(in_{{param.name}}_keys);
+  payload_size += GetSerializedSize_(in_{{param.name}}_values);
+{%-     elif param.kind|is_object_kind %}
   payload_size += GetSerializedSize_(in_{{param.name}});
 {%-     endif %}
 {%-   endfor %}
 {%- endmacro %}
 
 {%- macro build_message(params_name, parameters, params_description) -%}
   {# TODO(yzshen): Consider refactoring to share code with
      struct_serialization_definition.tmpl #}
   {{params_name}}* params =
       {{params_name}}::New(builder.buffer());
 {#--- Sets #}
 {%   for param in parameters %}
 {%-     if param.kind|is_object_kind %}
 {%-       if param.kind|is_any_array_kind %}
   mojo::SerializeArray_<{{param.kind|get_array_validate_params|indent(24)}}>(
       mojo::internal::Forward(in_{{param.name}}), builder.buffer(), &params->{{param.name}}.ptr);
+{%-     elif param.kind|is_map_kind %}
+  mojo::SerializeArray_<{{param.kind.key_kind|get_map_validate_params|indent(24)}}>(
+      mojo::internal::Forward(in_{{param.name}}_keys), builder.buffer(), &params->{{param.name}}_keys.ptr);
+  mojo::SerializeArray_<{{param.kind.value_kind|get_map_validate_params|indent(24)}}>(
+      mojo::internal::Forward(in_{{param.name}}_values), builder.buffer(), &params->{{param.name}}_values.ptr);
 {%-       else %}
   Serialize_(mojo::internal::Forward(in_{{param.name}}), builder.buffer(), &params->{{param.name}}.ptr);
 {%-       endif %}
 {%-       if not param.kind|is_nullable_kind %}
+{%-         if param.kind|is_map_kind %}
+  MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
+      !params->{{param.name}}_keys.ptr,
+      mojo::internal::VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
+      "null key array for {{param.name}} argument in {{params_description}}");
+  MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
+      !params->{{param.name}}_values.ptr,
+      mojo::internal::VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
+      "null key array for {{param.name}} argument in {{params_description}}");
+{%-         else %}
   MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
       !params->{{param.name}}.ptr,
       mojo::internal::VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
       "null {{param.name}} argument in {{params_description}}");
+{%-         endif %}
 {%-       endif %}
 {%-     elif param.kind|is_any_handle_kind %}
 {%-       if param.kind|is_interface_kind or
              param.kind|is_interface_request_kind %}
   // Delegate handle.
   params->{{param.name}} = in_{{param.name}}.PassMessagePipe().release();
 {%-       else %}
   params->{{param.name}} = in_{{param.name}}.release();
 {%-       endif %}
 {%-       if not param.kind|is_nullable_kind %}
@@ skipping 55 matching lines @@
 
 {%- for method in interface.methods %}
 {%-   set message_name =
           "internal::k%s_%s_Name"|format(interface.name, method.name) %}
 {%-   set params_name =
           "internal::%s_%s_Params_Data"|format(interface.name, method.name) %}
 {%-   set params_description =
           "%s.%s request"|format(interface.name, method.name) %}
 void {{proxy_name}}::{{method.name}}(
     {{interface_macros.declare_request_params("in_", method)}}) {
+  {{mapping_prelude(method.parameters)}}
+
   {{compute_payload_size(params_name, method.parameters)}}
 
 {%- if method.response_parameters != None %}
   mojo::internal::RequestMessageBuilder builder({{message_name}}, payload_size);
 {%- else %}
   mojo::internal::MessageBuilder builder({{message_name}}, payload_size);
 {%- endif %}
 
   {{build_message(params_name, method.parameters, params_description)}}
 
@@ skipping 35 matching lines @@
 
   virtual void Run({{interface_macros.declare_params("in_", method.response_parameters)}}) const override;
 
  private:
   uint64_t request_id_;
   mutable mojo::MessageReceiver* responder_;
   MOJO_DISALLOW_COPY_AND_ASSIGN({{class_name}}_{{method.name}}_ProxyToResponder);
 };
 void {{class_name}}_{{method.name}}_ProxyToResponder::Run(
     {{interface_macros.declare_params("in_", method.response_parameters)}}) const {
+  {{mapping_prelude(method.response_parameters)}}
+
   {{compute_payload_size(params_name, method.response_parameters)}}
   mojo::internal::ResponseMessageBuilder builder(
       {{message_name}}, payload_size, request_id_);
   {{build_message(params_name, method.response_parameters, params_description)}}
   bool ok MOJO_ALLOW_UNUSED = responder_->Accept(&message);
   // TODO(darin): !ok returned here indicates a malformed message, and that may
   // be good reason to close the connection. However, we don't have a way to do
   // that from here. We should add a way.
   delete responder_;
   responder_ = nullptr;
@@ skipping 119 matching lines @@
       }
       break;
     }
 {%-   endfor %}
   }
 {%- endif %}
 
   return sink_->Accept(message);
 }
 {%- endif -%}