message_memory_strategy.hpp

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// Copyright 2015 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__MESSAGE_MEMORY_STRATEGY_HPP_
#define RCLCPP__MESSAGE_MEMORY_STRATEGY_HPP_

#include <memory>
#include <stdexcept>

#include "rcl/types.h"

#include "rclcpp/allocator/allocator_common.hpp"
#include "rclcpp/exceptions.hpp"
#include "rclcpp/macros.hpp"
#include "rclcpp/visibility_control.hpp"

#include "rmw/serialized_message.h"

namespace rclcpp
{
namespace message_memory_strategy
{


template<typename MessageT, typename Alloc = std::allocator<void>>
class MessageMemoryStrategy
{
public:
  RCLCPP_SMART_PTR_DEFINITIONS(MessageMemoryStrategy)

  using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
  using MessageAlloc = typename MessageAllocTraits::allocator_type;
  using MessageDeleter = allocator::Deleter<MessageAlloc, MessageT>;

  using SerializedMessageAllocTraits = allocator::AllocRebind<rcl_serialized_message_t, Alloc>;
  using SerializedMessageAlloc = typename SerializedMessageAllocTraits::allocator_type;
  using SerializedMessageDeleter =
    allocator::Deleter<SerializedMessageAlloc, rcl_serialized_message_t>;

  using BufferAllocTraits = allocator::AllocRebind<char, Alloc>;
  using BufferAlloc = typename BufferAllocTraits::allocator_type;
  using BufferDeleter = allocator::Deleter<BufferAlloc, char>;

  MessageMemoryStrategy()
  {
    message_allocator_ = std::make_shared<MessageAlloc>();
    serialized_message_allocator_ = std::make_shared<SerializedMessageAlloc>();
    buffer_allocator_ = std::make_shared<BufferAlloc>();
    rcutils_allocator_ = allocator::get_rcl_allocator<char, BufferAlloc>(*buffer_allocator_.get());
  }

  explicit MessageMemoryStrategy(std::shared_ptr<Alloc> allocator)
  {
    message_allocator_ = std::make_shared<MessageAlloc>(*allocator.get());
    serialized_message_allocator_ = std::make_shared<SerializedMessageAlloc>(*allocator.get());
    buffer_allocator_ = std::make_shared<BufferAlloc>(*allocator.get());
    rcutils_allocator_ = allocator::get_rcl_allocator<char, BufferAlloc>(*buffer_allocator_.get());
  }

  static SharedPtr create_default()
  {
    return std::make_shared<MessageMemoryStrategy<MessageT, Alloc>>(std::make_shared<Alloc>());
  }


  virtual std::shared_ptr<MessageT> borrow_message()
  {
    return std::allocate_shared<MessageT, MessageAlloc>(*message_allocator_.get());
  }

  virtual std::shared_ptr<rcl_serialized_message_t> borrow_serialized_message(size_t capacity)
  {
    auto msg = new rcl_serialized_message_t;
    *msg = rmw_get_zero_initialized_serialized_message();
    auto ret = rmw_serialized_message_init(msg, capacity, &rcutils_allocator_);
    if (ret != RCL_RET_OK) {
      rclcpp::exceptions::throw_from_rcl_error(ret);
    }

    auto serialized_msg = std::shared_ptr<rcl_serialized_message_t>(msg,
        [](rmw_serialized_message_t * msg) {
          auto ret = rmw_serialized_message_fini(msg);
          delete msg;
          if (ret != RCL_RET_OK) {
            rclcpp::exceptions::throw_from_rcl_error(ret, "leaking memory");
          }
        });

    return serialized_msg;
  }

  virtual std::shared_ptr<rcl_serialized_message_t> borrow_serialized_message()
  {
    return borrow_serialized_message(default_buffer_capacity_);
  }

  virtual void set_default_buffer_capacity(size_t capacity)
  {
    default_buffer_capacity_ = capacity;
  }


  virtual void return_message(std::shared_ptr<MessageT> & msg)
  {
    msg.reset();
  }

  virtual void return_serialized_message(std::shared_ptr<rcl_serialized_message_t> & serialized_msg)
  {
    serialized_msg.reset();
  }

  std::shared_ptr<MessageAlloc> message_allocator_;
  MessageDeleter message_deleter_;

  std::shared_ptr<SerializedMessageAlloc> serialized_message_allocator_;
  SerializedMessageDeleter serialized_message_deleter_;

  std::shared_ptr<BufferAlloc> buffer_allocator_;
  BufferDeleter buffer_deleter_;
  size_t default_buffer_capacity_ = 0;

  rcutils_allocator_t rcutils_allocator_;
};

}  // namespace message_memory_strategy
}  // namespace rclcpp

#endif  // RCLCPP__MESSAGE_MEMORY_STRATEGY_HPP_