.. _program_listing_file_include_rclcpp_experimental_buffers_ring_buffer_implementation.hpp:

Program Listing for File ring_buffer_implementation.hpp
=======================================================

|exhale_lsh| :ref:`Return to documentation for file <file_include_rclcpp_experimental_buffers_ring_buffer_implementation.hpp>` (``include/rclcpp/experimental/buffers/ring_buffer_implementation.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // Copyright 2019 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__EXPERIMENTAL__BUFFERS__RING_BUFFER_IMPLEMENTATION_HPP_
   #define RCLCPP__EXPERIMENTAL__BUFFERS__RING_BUFFER_IMPLEMENTATION_HPP_
   
   #include <mutex>
   #include <stdexcept>
   #include <utility>
   #include <vector>
   
   #include "rclcpp/experimental/buffers/buffer_implementation_base.hpp"
   #include "rclcpp/logger.hpp"
   #include "rclcpp/logging.hpp"
   #include "rclcpp/macros.hpp"
   #include "rclcpp/visibility_control.hpp"
   
   namespace rclcpp
   {
   namespace experimental
   {
   namespace buffers
   {
   
   
   template<typename BufferT>
   class RingBufferImplementation : public BufferImplementationBase<BufferT>
   {
   public:
     explicit RingBufferImplementation(size_t capacity)
     : capacity_(capacity),
       ring_buffer_(capacity),
       write_index_(capacity_ - 1),
       read_index_(0),
       size_(0)
     {
       if (capacity == 0) {
         throw std::invalid_argument("capacity must be a positive, non-zero value");
       }
     }
   
     virtual ~RingBufferImplementation() {}
   
   
     void enqueue(BufferT request)
     {
       std::lock_guard<std::mutex> lock(mutex_);
   
       write_index_ = next_(write_index_);
       ring_buffer_[write_index_] = std::move(request);
   
       if (is_full_()) {
         read_index_ = next_(read_index_);
       } else {
         size_++;
       }
     }
   
   
     BufferT dequeue()
     {
       std::lock_guard<std::mutex> lock(mutex_);
   
       if (!has_data_()) {
         return BufferT();
       }
   
       auto request = std::move(ring_buffer_[read_index_]);
       read_index_ = next_(read_index_);
   
       size_--;
   
       return request;
     }
   
   
     inline size_t next(size_t val)
     {
       std::lock_guard<std::mutex> lock(mutex_);
       return next_(val);
     }
   
   
     inline bool has_data() const
     {
       std::lock_guard<std::mutex> lock(mutex_);
       return has_data_();
     }
   
   
     inline bool is_full() const
     {
       std::lock_guard<std::mutex> lock(mutex_);
       return is_full_();
     }
   
     void clear() {}
   
   private:
   
     inline size_t next_(size_t val)
     {
       return (val + 1) % capacity_;
     }
   
   
     inline bool has_data_() const
     {
       return size_ != 0;
     }
   
   
     inline bool is_full_() const
     {
       return size_ == capacity_;
     }
   
     size_t capacity_;
   
     std::vector<BufferT> ring_buffer_;
   
     size_t write_index_;
     size_t read_index_;
     size_t size_;
   
     mutable std::mutex mutex_;
   };
   
   }  // namespace buffers
   }  // namespace experimental
   }  // namespace rclcpp
   
   #endif  // RCLCPP__EXPERIMENTAL__BUFFERS__RING_BUFFER_IMPLEMENTATION_HPP_