subscription.hpp

// Copyright 2014 Open Source Robotics Foundation, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#ifndef RCLCPP__SUBSCRIPTION_HPP_
#define RCLCPP__SUBSCRIPTION_HPP_
 
#include <rmw/error_handling.h>
#include <rmw/rmw.h>
 
#include <functional>
#include <memory>
#include <string>
#include <utility>
 
#include "rcl/error_handling.h"
#include "rcl/subscription.h"
 
#include "rclcpp/any_subscription_callback.hpp"
#include "rclcpp/detail/resolve_use_intra_process.hpp"
#include "rclcpp/detail/resolve_intra_process_buffer_type.hpp"
#include "rclcpp/exceptions.hpp"
#include "rclcpp/expand_topic_or_service_name.hpp"
#include "rclcpp/experimental/intra_process_manager.hpp"
#include "rclcpp/experimental/subscription_intra_process.hpp"
#include "rclcpp/logging.hpp"
#include "rclcpp/macros.hpp"
#include "rclcpp/message_info.hpp"
#include "rclcpp/message_memory_strategy.hpp"
#include "rclcpp/node_interfaces/node_base_interface.hpp"
#include "rclcpp/subscription_base.hpp"
#include "rclcpp/subscription_options.hpp"
#include "rclcpp/type_support_decl.hpp"
#include "rclcpp/visibility_control.hpp"
#include "rclcpp/waitable.hpp"
#include "tracetools/tracetools.h"
 
namespace rclcpp
{
 
namespace node_interfaces
{
class NodeTopicsInterface;
}  // namespace node_interfaces
 
template<
  typename MessageT,
  typename AllocatorT = std::allocator<void>,
  typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type,
  typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type,
  typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<
    ROSMessageT,
    AllocatorT
  >>
class Subscription : public SubscriptionBase
{
  friend class rclcpp::node_interfaces::NodeTopicsInterface;
 
public:
  // Redeclare these here to use outside of the class.
  using SubscribedType = SubscribedT;
  using ROSMessageType = ROSMessageT;
  using MessageMemoryStrategyType = MessageMemoryStrategyT;
 
  using SubscribedTypeAllocatorTraits = allocator::AllocRebind<SubscribedType, AllocatorT>;
  using SubscribedTypeAllocator = typename SubscribedTypeAllocatorTraits::allocator_type;
  using SubscribedTypeDeleter = allocator::Deleter<SubscribedTypeAllocator, SubscribedType>;
 
  using ROSMessageTypeAllocatorTraits = allocator::AllocRebind<ROSMessageType, AllocatorT>;
  using ROSMessageTypeAllocator = typename ROSMessageTypeAllocatorTraits::allocator_type;
  using ROSMessageTypeDeleter = allocator::Deleter<ROSMessageTypeAllocator, ROSMessageType>;
 
public:
  RCLCPP_SMART_PTR_DEFINITIONS(Subscription)
 
  
  // *INDENT-OFF*
  Subscription(
    rclcpp::node_interfaces::NodeBaseInterface * node_base,
    const rosidl_message_type_support_t & type_support_handle,
    const std::string & topic_name,
    const rclcpp::QoS & qos,
    AnySubscriptionCallback<MessageT, AllocatorT> callback,
    const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options,
    typename MessageMemoryStrategyT::SharedPtr message_memory_strategy)
  : SubscriptionBase(
      node_base,
      type_support_handle,
      topic_name,
      options.to_rcl_subscription_options(qos),
      // NOTE(methylDragon): Passing these args separately is necessary for event binding
      options.event_callbacks,
      options.use_default_callbacks,
      callback.is_serialized_message_callback() ? DeliveredMessageKind::SERIALIZED_MESSAGE : DeliveredMessageKind::ROS_MESSAGE),  // NOLINT
    any_callback_(callback),
    options_(options),
    message_memory_strategy_(message_memory_strategy)
  // *INDENT-ON*
  {
    // Setup intra process publishing if requested.
    if (rclcpp::detail::resolve_use_intra_process(options_, *node_base)) {
      using rclcpp::detail::resolve_intra_process_buffer_type;
 
      // Check if the QoS is compatible with intra-process.
      auto qos_profile = get_actual_qos();
      if (qos_profile.history() != rclcpp::HistoryPolicy::KeepLast) {
        throw std::invalid_argument(
                "intraprocess communication on topic '" + topic_name +
                "' allowed only with keep last history qos policy");
      }
      if (qos_profile.depth() == 0) {
        throw std::invalid_argument(
                "intraprocess communication on topic '" + topic_name +
                "' is not allowed with 0 depth qos policy");
      }
 
      using SubscriptionIntraProcessT = rclcpp::experimental::SubscriptionIntraProcess<
        MessageT,
        SubscribedType,
        SubscribedTypeAllocator,
        SubscribedTypeDeleter,
        ROSMessageT,
        AllocatorT>;
 
      // First create a SubscriptionIntraProcess which will be given to the intra-process manager.
      auto context = node_base->get_context();
      subscription_intra_process_ = std::make_shared<SubscriptionIntraProcessT>(
        callback,
        options_.get_allocator(),
        context,
        this->get_topic_name(),  // important to get like this, as it has the fully-qualified name
        qos_profile,
        resolve_intra_process_buffer_type(options_.intra_process_buffer_type, callback));
      TRACETOOLS_TRACEPOINT(
        rclcpp_subscription_init,
        static_cast<const void *>(get_subscription_handle().get()),
        static_cast<const void *>(subscription_intra_process_.get()));
 
      // Add it to the intra process manager.
      using rclcpp::experimental::IntraProcessManager;
      auto ipm = context->get_sub_context<IntraProcessManager>();
      uint64_t intra_process_subscription_id = ipm->template add_subscription<
        ROSMessageType, ROSMessageTypeAllocator>(subscription_intra_process_);
      this->setup_intra_process(intra_process_subscription_id, ipm);
    }
 
    TRACETOOLS_TRACEPOINT(
      rclcpp_subscription_init,
      static_cast<const void *>(get_subscription_handle().get()),
      static_cast<const void *>(this));
    TRACETOOLS_TRACEPOINT(
      rclcpp_subscription_callback_added,
      static_cast<const void *>(this),
      static_cast<const void *>(&any_callback_));
    // The callback object gets copied, so if registration is done too early/before this point
    // (e.g. in `AnySubscriptionCallback::set()`), its address won't match any address used later
    // in subsequent tracepoints.
#ifndef TRACETOOLS_DISABLED
    any_callback_.register_callback_for_tracing();
#endif
  }
 
  void
  post_init_setup(
    [[maybe_unused]] rclcpp::node_interfaces::NodeBaseInterface * node_base,
    [[maybe_unused]] const rclcpp::QoS & qos,
    [[maybe_unused]] const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options)
  {
    // This function is intentionally left empty.
  }
 
 
  bool
  take(ROSMessageType & message_out, rclcpp::MessageInfo & message_info_out)
  {
    return this->take_type_erased(static_cast<void *>(&message_out), message_info_out);
  }
 
 
  template<typename TakeT>
  std::enable_if_t<
    !rosidl_generator_traits::is_message<TakeT>::value &&
    std::is_same_v<TakeT, SubscribedType>,
    bool
  >
  take(TakeT & message_out, rclcpp::MessageInfo & message_info_out)
  {
    ROSMessageType local_message;
    bool taken = this->take_type_erased(static_cast<void *>(&local_message), message_info_out);
    if (taken) {
      rclcpp::TypeAdapter<MessageT>::convert_to_custom(local_message, message_out);
    }
    return taken;
  }
 
  std::shared_ptr<void>
  create_message() override
  {
    /* The default message memory strategy provides a dynamically allocated message on each call to
     * create_message, though alternative memory strategies that re-use a preallocated message may be
     * used (see rclcpp/strategies/message_pool_memory_strategy.hpp).
     */
    return message_memory_strategy_->borrow_message();
  }
 
  std::shared_ptr<rclcpp::SerializedMessage>
  create_serialized_message() override
  {
    return message_memory_strategy_->borrow_serialized_message();
  }
 
 
  void
  disable_callbacks() override
  {
    SubscriptionBase::disable_callbacks();
    any_callback_.disable();
    if (subscription_intra_process_) {
      subscription_intra_process_->disable_callbacks();
    }
    for (const auto & [_, event_ptr] : event_handlers_) {
      if (event_ptr) {
        event_ptr->disable();
      }
    }
  }
 
 
  void
  enable_callbacks() override
  {
    SubscriptionBase::enable_callbacks();
    any_callback_.enable();
    if (subscription_intra_process_) {
      subscription_intra_process_->enable_callbacks();
    }
    for (const auto & [_, event_ptr] : event_handlers_) {
      if (event_ptr) {
        event_ptr->enable();
      }
    }
  }
 
  void
  handle_message(
    std::shared_ptr<void> & message,
    const rclcpp::MessageInfo & message_info) override
  {
    if (matches_any_intra_process_publishers(&message_info.get_rmw_message_info().publisher_gid)) {
      // In this case, the message will be delivered via intra process and
      // we should ignore this copy of the message.
      return;
    }
    auto typed_message = std::static_pointer_cast<ROSMessageType>(message);
    any_callback_.dispatch(typed_message, message_info);
  }
 
  void
  handle_serialized_message(
    const std::shared_ptr<rclcpp::SerializedMessage> & serialized_message,
    const rclcpp::MessageInfo & message_info) override
  {
    any_callback_.dispatch(serialized_message, message_info);
  }
 
  void
  handle_loaned_message(
    void * loaned_message,
    const rclcpp::MessageInfo & message_info) override
  {
    if (matches_any_intra_process_publishers(&message_info.get_rmw_message_info().publisher_gid)) {
      // In this case, the message will be delivered via intra process and
      // we should ignore this copy of the message.
      return;
    }
 
    auto typed_message = static_cast<ROSMessageType *>(loaned_message);
    // message is loaned, so we have to make sure that the deleter does not deallocate the message
    auto sptr = std::shared_ptr<ROSMessageType>(
      typed_message, [](ROSMessageType * msg) {(void) msg;});
    any_callback_.dispatch(sptr, message_info);
  }
 
 
  void
  return_message(std::shared_ptr<void> & message) override
  {
    auto typed_message = std::static_pointer_cast<ROSMessageType>(message);
    message_memory_strategy_->return_message(typed_message);
  }
 
 
  void
  return_serialized_message(std::shared_ptr<rclcpp::SerializedMessage> & message) override
  {
    message_memory_strategy_->return_serialized_message(message);
  }
 
  bool
  use_take_shared_method() const
  {
    return any_callback_.use_take_shared_method();
  }
 
  // DYNAMIC TYPE ==================================================================================
  // TODO(methylDragon): Reorder later
  // TODO(methylDragon): Implement later...
  rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr
  get_shared_dynamic_message_type() override
  {
    throw rclcpp::exceptions::UnimplementedError(
            "get_shared_dynamic_message_type is not implemented for Subscription");
  }
 
  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
  get_shared_dynamic_message() override
  {
    throw rclcpp::exceptions::UnimplementedError(
            "get_shared_dynamic_message is not implemented for Subscription");
  }
 
  rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr
  get_shared_dynamic_serialization_support() override
  {
    throw rclcpp::exceptions::UnimplementedError(
            "get_shared_dynamic_serialization_support is not implemented for Subscription");
  }
 
  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
  create_dynamic_message() override
  {
    throw rclcpp::exceptions::UnimplementedError(
            "create_dynamic_message is not implemented for Subscription");
  }
 
  void
  return_dynamic_message(
    [[maybe_unused]] rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message) override
  {
    throw rclcpp::exceptions::UnimplementedError(
            "return_dynamic_message is not implemented for Subscription");
  }
 
  void
  handle_dynamic_message(
    [[maybe_unused]] const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message,
    [[maybe_unused]] const rclcpp::MessageInfo & message_info) override
  {
    throw rclcpp::exceptions::UnimplementedError(
            "handle_dynamic_message is not implemented for Subscription");
  }
 
private:
  RCLCPP_DISABLE_COPY(Subscription)
 
  AnySubscriptionCallback<MessageT, AllocatorT> any_callback_;
 
  const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> options_;
  typename message_memory_strategy::MessageMemoryStrategy<ROSMessageType, AllocatorT>::SharedPtr
    message_memory_strategy_;
};
 
}  // namespace rclcpp
 
#endif  // RCLCPP__SUBSCRIPTION_HPP_