path: root/mojo/public/tools/bindings/generators/cpp_templates/interface_definition.tmpl

{%- import "interface_macros.tmpl" as interface_macros %}
{%- import "struct_macros.tmpl" as struct_macros %}

{%- set class_name = interface.name %}
{%- set proxy_name = interface.name ~ "Proxy" %}
{%- set namespace_as_string = "%s"|format(namespace|replace(".","::")) %}

{%- macro alloc_params(struct, serialization_context) %}
  bool success = true;
{%-   for param in struct.packed.packed_fields_in_ordinal_order %}
  {{param.field.kind|cpp_wrapper_type}} p_{{param.field.name}}{};
{%-   endfor %}
  {{struct_macros.deserialize(struct, "params", "p_%s", serialization_context, "success")}}
  if (!success)
    return false;
{%- endmacro %}

{%- macro pass_params(parameters) %}
{%-   for param in parameters %}
{%-     if param.kind|is_move_only_kind -%}
std::move(p_{{param.name}})
{%-     else -%}
p_{{param.name}}
{%-     endif -%}
{%-     if not loop.last %}, {% endif %}
{%-   endfor %}
{%- endmacro %}

{%- macro build_message(struct, input_pattern, struct_display_name,
                        serialization_context) -%}
  {{struct_macros.serialize(struct, struct_display_name, input_pattern,
                            "params", "builder.buffer()",
                            serialization_context)}}
  params->EncodePointersAndHandles(builder.message()->mutable_handles());
{%- endmacro %}

{#--- Begin #}
MOJO_STATIC_CONST_MEMBER_DEFINITION const char {{class_name}}::Name_[] = "{{namespace_as_string}}::{{class_name}}";
MOJO_STATIC_CONST_MEMBER_DEFINITION const uint32_t {{class_name}}::Version_;

{#--- Constants #}
{%-  for constant in interface.constants %}
{%-   if constant.kind|is_integral_kind %}
MOJO_STATIC_CONST_MEMBER_DEFINITION const {{constant.kind|cpp_pod_type}} {{interface.name}}::{{constant.name}};
{%-   else %}
MOJO_STATIC_CONST_MEMBER_DEFINITION const {{constant.kind|cpp_pod_type}} {{interface.name}}::{{constant.name}} = {{constant|constant_value}};
{%-   endif %}
{%- endfor %}

{#--- ForwardToCallback definition #}
{%- for method in interface.methods -%}
{%-   if method.response_parameters != None %}
{%-     if method.sync %}
class {{class_name}}_{{method.name}}_HandleSyncResponse
    : public mojo::MessageReceiver {
 public:
  {{class_name}}_{{method.name}}_HandleSyncResponse(
      scoped_refptr<mojo::internal::MultiplexRouter> router, bool* result
{%-       for param in method.response_parameters -%}
      , {{param.kind|cpp_wrapper_type}}* out_{{param.name}}
{%-       endfor %})
      : serialization_context_(std::move(router)), result_(result)
{%-       for param in method.response_parameters -%}
        , out_{{param.name}}_(out_{{param.name}})
{%-       endfor %} {
    DCHECK(!*result_);
  }
  bool Accept(mojo::Message* message) override;
 private:
  mojo::internal::SerializationContext serialization_context_;
  bool* result_;
{%-       for param in method.response_parameters %}
  {{param.kind|cpp_wrapper_type}}* out_{{param.name}}_;
{%-       endfor -%}
  DISALLOW_COPY_AND_ASSIGN({{class_name}}_{{method.name}}_HandleSyncResponse);
};
bool {{class_name}}_{{method.name}}_HandleSyncResponse::Accept(
    mojo::Message* message) {
  internal::{{class_name}}_{{method.name}}_ResponseParams_Data* params =
      reinterpret_cast<internal::{{class_name}}_{{method.name}}_ResponseParams_Data*>(
          message->mutable_payload());

  params->DecodePointersAndHandles(message->mutable_handles());
  {{alloc_params(method.response_param_struct, "&serialization_context_")}}

{%-       for param in method.response_parameters %}
{%-         if param.kind|is_move_only_kind %}
  *out_{{param.name}}_ = std::move(p_{{param.name}});
{%-         else %}
  *out_{{param.name}}_ = p_{{param.name}};
{%-         endif %}
{%-       endfor %}
  *result_ = true;
  return true;
}
{%-     endif %}

class {{class_name}}_{{method.name}}_ForwardToCallback
    : public mojo::MessageReceiver {
 public:
  {{class_name}}_{{method.name}}_ForwardToCallback(
      const {{class_name}}::{{method.name}}Callback& callback,
      scoped_refptr<mojo::internal::MultiplexRouter> router)
      : callback_(callback), serialization_context_(std::move(router)) {
  }
  bool Accept(mojo::Message* message) override;
 private:
  {{class_name}}::{{method.name}}Callback callback_;
  mojo::internal::SerializationContext serialization_context_;
  DISALLOW_COPY_AND_ASSIGN({{class_name}}_{{method.name}}_ForwardToCallback);
};
bool {{class_name}}_{{method.name}}_ForwardToCallback::Accept(
    mojo::Message* message) {
  internal::{{class_name}}_{{method.name}}_ResponseParams_Data* params =
      reinterpret_cast<internal::{{class_name}}_{{method.name}}_ResponseParams_Data*>(
          message->mutable_payload());

  params->DecodePointersAndHandles(message->mutable_handles());
  {{alloc_params(method.response_param_struct, "&serialization_context_")}}
  callback_.Run({{pass_params(method.response_parameters)}});
  return true;
}
{%-   endif %}
{%- endfor %}

{{proxy_name}}::{{proxy_name}}(mojo::MessageReceiverWithResponder* receiver)
    : ControlMessageProxy(receiver) {
}

{#--- Proxy definitions #}

{%- for method in interface.methods %}
{%-   set message_name =
          "internal::k%s_%s_Name"|format(interface.name, method.name) %}
{%-   set params_struct = method.param_struct %}
{%-   set params_description =
          "%s.%s request"|format(interface.name, method.name) %}
{%-   if method.sync %}
bool {{proxy_name}}::{{method.name}}(
    {{interface_macros.declare_sync_method_params("param_", method)}}) {
  {{struct_macros.get_serialized_size(params_struct, "param_%s",
                                      "&serialization_context_")}}

  mojo::internal::RequestMessageBuilder builder({{message_name}}, size,
                                                mojo::internal::kMessageIsSync);

  {{build_message(params_struct, "param_%s", params_description,
                  "&serialization_context_")}}

  bool result = false;
  mojo::MessageReceiver* responder =
      new {{class_name}}_{{method.name}}_HandleSyncResponse(
          serialization_context_.router, &result
{%-     for param in method.response_parameters -%}
          , param_{{param.name}}
{%-     endfor %});
  if (!receiver_->AcceptWithResponder(builder.message(), responder))
    delete responder;
  return result;
}
{%-   endif %}

void {{proxy_name}}::{{method.name}}(
    {{interface_macros.declare_request_params("in_", method)}}) {
  {{struct_macros.get_serialized_size(params_struct, "in_%s",
                                      "&serialization_context_")}}

{%- if method.response_parameters != None %}
  mojo::internal::RequestMessageBuilder builder({{message_name}}, size);
{%- else %}
  mojo::internal::MessageBuilder builder({{message_name}}, size);
{%- endif %}

  {{build_message(params_struct, "in_%s", params_description,
                  "&serialization_context_")}}

{%- if method.response_parameters != None %}
  mojo::MessageReceiver* responder =
      new {{class_name}}_{{method.name}}_ForwardToCallback(callback, serialization_context_.router);
  if (!receiver_->AcceptWithResponder(builder.message(), responder))
    delete responder;
{%- else %}
  bool ok = receiver_->Accept(builder.message());
  // This return value may be ignored as !ok implies the Connector has
  // encountered an error, which will be visible through other means.
  ALLOW_UNUSED_LOCAL(ok);
{%- endif %}
}
{%- endfor %}

{#--- ProxyToResponder definition #}
{%- for method in interface.methods -%}
{%-   if method.response_parameters != None %}
{%-     set message_name =
            "internal::k%s_%s_Name"|format(interface.name, method.name) %}
{%-     set response_params_struct = method.response_param_struct %}
{%-     set params_description =
            "%s.%s response"|format(interface.name, method.name) %}
class {{class_name}}_{{method.name}}_ProxyToResponder
    : public {{class_name}}::{{method.name}}Callback::Runnable {
 public:
  ~{{class_name}}_{{method.name}}_ProxyToResponder() override {
    // Is the Mojo application destroying the callback without running it
    // and without first closing the pipe?
    bool callback_was_dropped = responder_ && responder_->IsValid();
    // If the Callback was dropped then deleting the responder will close
    // the pipe so the calling application knows to stop waiting for a reply.
    delete responder_;
    DCHECK(!callback_was_dropped)  << "The callback passed to "
        "{{class_name}}::{{method.name}}({%- if method.parameters -%}{{pass_params(method.parameters)}}, {% endif -%}callback) "
        "was never run.";
  }

  {{class_name}}_{{method.name}}_ProxyToResponder(
      uint64_t request_id,
      bool is_sync,
      mojo::MessageReceiverWithStatus* responder,
      scoped_refptr<mojo::internal::MultiplexRouter> router)
      : request_id_(request_id),
        is_sync_(is_sync),
        responder_(responder),
        serialization_context_(std::move(router)) {
  }

  void Run({{interface_macros.declare_params("in_", method.response_parameters)}}) const override;

 private:
  uint64_t request_id_;
  bool is_sync_;
  mutable mojo::MessageReceiverWithStatus* responder_;
  // TODO(yzshen): maybe I should use a ref to the original one?
  mutable mojo::internal::SerializationContext serialization_context_;
  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 {
  {{struct_macros.get_serialized_size(response_params_struct, "in_%s",
                                      "&serialization_context_")}}
  mojo::internal::ResponseMessageBuilder builder(
      {{message_name}}, size, request_id_,
      is_sync_ ? mojo::internal::kMessageIsSync : 0);
  {{build_message(response_params_struct, "in_%s", params_description,
                  "&serialization_context_")}}
  bool ok = responder_->Accept(builder.message());
  ALLOW_UNUSED_LOCAL(ok);
  // 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;
}
{%-   endif -%}
{%- endfor %}

{{class_name}}Stub::{{class_name}}Stub()
    : sink_(nullptr),
      control_message_handler_({{interface.name}}::Version_) {
}

{{class_name}}Stub::~{{interface.name}}Stub() {}

{#--- Stub definition #}

bool {{class_name}}Stub::Accept(mojo::Message* message) {
  if (mojo::internal::ControlMessageHandler::IsControlMessage(message))
    return control_message_handler_.Accept(message);
{%- if interface.methods %}
  switch (message->header()->name) {
{%-   for method in interface.methods %}
    case internal::k{{class_name}}_{{method.name}}_Name: {
{%-     if method.response_parameters == None %}
      internal::{{class_name}}_{{method.name}}_Params_Data* params =
          reinterpret_cast<internal::{{class_name}}_{{method.name}}_Params_Data*>(
              message->mutable_payload());

      params->DecodePointersAndHandles(message->mutable_handles());
      {{alloc_params(method.param_struct, "&serialization_context_")|indent(4)}}
      // A null |sink_| means no implementation was bound.
      assert(sink_);
      TRACE_EVENT0("mojom", "{{class_name}}::{{method.name}}");
      sink_->{{method.name}}({{pass_params(method.parameters)}});
      return true;
{%-     else %}
      break;
{%-     endif %}
    }
{%-   endfor %}
  }
{%- endif %}
  return false;
}

bool {{class_name}}Stub::AcceptWithResponder(
    mojo::Message* message, mojo::MessageReceiverWithStatus* responder) {
  if (mojo::internal::ControlMessageHandler::IsControlMessage(message))
    return control_message_handler_.AcceptWithResponder(message, responder);
{%- if interface.methods %}
  switch (message->header()->name) {
{%-   for method in interface.methods %}
    case internal::k{{class_name}}_{{method.name}}_Name: {
{%-     if method.response_parameters != None %}
      internal::{{class_name}}_{{method.name}}_Params_Data* params =
          reinterpret_cast<internal::{{class_name}}_{{method.name}}_Params_Data*>(
              message->mutable_payload());

      params->DecodePointersAndHandles(message->mutable_handles());
      {{alloc_params(method.param_struct, "&serialization_context_")|indent(4)}}
      {{class_name}}::{{method.name}}Callback::Runnable* runnable =
          new {{class_name}}_{{method.name}}_ProxyToResponder(
              message->request_id(),
              message->has_flag(mojo::internal::kMessageIsSync),
              responder,
              serialization_context_.router);
      {{class_name}}::{{method.name}}Callback callback(runnable);
      // A null |sink_| means no implementation was bound.
      assert(sink_);
      TRACE_EVENT0("mojom", "{{class_name}}::{{method.name}}");
      sink_->{{method.name}}(
{%- if method.parameters -%}{{pass_params(method.parameters)}}, {% endif -%}callback);
      return true;
{%-     else %}
      break;
{%-     endif %}
    }
{%-   endfor %}
  }
{%- endif %}
  return false;
}

{#--- Request validator definitions #}

{{class_name}}RequestValidator::{{class_name}}RequestValidator(
    mojo::MessageReceiver* sink) : MessageFilter(sink) {
}

bool {{class_name}}RequestValidator::Accept(mojo::Message* message) {
  assert(sink_);

  if (mojo::internal::ControlMessageHandler::IsControlMessage(message)) {
    if (!mojo::internal::ValidateControlRequest(message))
      return false;
    return sink_->Accept(message);
  }

  switch (message->header()->name) {
{%- for method in interface.methods %}
    case internal::k{{class_name}}_{{method.name}}_Name: {
{%-   if method.response_parameters != None %}
      if (!mojo::internal::ValidateMessageIsRequestExpectingResponse(message))
        return false;
{%-   else %}
      if (!mojo::internal::ValidateMessageIsRequestWithoutResponse(message))
        return false;
{%-   endif %}
      if (!mojo::internal::ValidateMessagePayload<
               internal::{{class_name}}_{{method.name}}_Params_Data>(message)) {
        return false;
      }
      return sink_->Accept(message);
    }
{%- endfor %}
    default:
      break;
  }

  // Unrecognized message.
  ReportValidationError(
      mojo::internal::VALIDATION_ERROR_MESSAGE_HEADER_UNKNOWN_METHOD);
  return false;
}

{#--- Response validator definitions #}
{% if interface|has_callbacks %}
{{class_name}}ResponseValidator::{{class_name}}ResponseValidator(
    mojo::MessageReceiver* sink) : MessageFilter(sink) {
}

bool {{class_name}}ResponseValidator::Accept(mojo::Message* message) {
  assert(sink_);

  if (mojo::internal::ControlMessageHandler::IsControlMessage(message)) {
    if (!mojo::internal::ValidateControlResponse(message))
      return false;
    return sink_->Accept(message);
  }

  if (!mojo::internal::ValidateMessageIsResponse(message))
    return false;
  switch (message->header()->name) {
{%- for method in interface.methods if method.response_parameters != None %}
    case internal::k{{class_name}}_{{method.name}}_Name: {
      if (!mojo::internal::ValidateMessagePayload<
               internal::{{class_name}}_{{method.name}}_ResponseParams_Data>(message)) {
        return false;
      }
      return sink_->Accept(message);
    }
{%- endfor %}
    default:
      break;
  }

  // Unrecognized message.
  ReportValidationError(
      mojo::internal::VALIDATION_ERROR_MESSAGE_HEADER_UNKNOWN_METHOD);
  return false;
}
{%- endif -%}