fsfw/contrib/fsfw_contrib/etl-20.39.4/include/etl/priority_queue.h

///\file

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com

Copyright(c) 2015 John Wellbelove, rlindeman

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#ifndef ETL_PRIORITY_QUEUE_INCLUDED
#define ETL_PRIORITY_QUEUE_INCLUDED

#include "platform.h"
#include "algorithm.h"
#include "utility.h"
#include "functional.h"
#include "iterator.h"
#include "vector.h"
#include "type_traits.h"
#include "parameter_type.h"
#include "error_handler.h"
#include "exception.h"

#include <stddef.h>

//*****************************************************************************
///\defgroup queue queue
/// A priority queue with the capacity defined at compile time,
/// written in the STL style.
///\ingroup containers
//*****************************************************************************

namespace etl
{
  //***************************************************************************
  /// The base class for priority_queue exceptions.
  ///\ingroup queue
  //***************************************************************************
  class priority_queue_exception : public exception
  {
  public:

    priority_queue_exception(string_type reason_, string_type file_name_, numeric_type line_number_)
      : exception(reason_, file_name_, line_number_)
    {
    }
  };

  //***************************************************************************
  /// The exception thrown when the queue is full.
  ///\ingroup queue
  //***************************************************************************
  class priority_queue_full : public etl::priority_queue_exception
  {
  public:

    priority_queue_full(string_type file_name_, numeric_type line_number_)
      : priority_queue_exception(ETL_ERROR_TEXT("priority_queue:full", ETL_PRIORITY_QUEUE_FILE_ID"A"), file_name_, line_number_)
    {
    }
  };

  //***************************************************************************
  /// The priority queue iterator exception on reversed iterators
  ///\ingroup queue
  //***************************************************************************
  class priority_queue_iterator : public etl::priority_queue_exception
  {
  public:

    priority_queue_iterator(string_type file_name_, numeric_type line_number_)
      : priority_queue_exception(ETL_ERROR_TEXT("priority_queue:iterator", ETL_PRIORITY_QUEUE_FILE_ID"B"), file_name_, line_number_)
    {
    }
  };

  //***************************************************************************
  ///\ingroup queue
  ///\brief This is the base for all priority queues that contain a particular type.
  ///\details Normally a reference to this type will be taken from a derived queue.
  /// The TContainer specified must provide the front, push_back, pop_back, and
  /// assign methods to work correctly with priority_queue.
  ///\code
  /// etl::priority_queue<int, 10> myPriorityQueue;
  /// etl::ipriority_queue<int>& iQueue = myPriorityQueue;
  ///\endcode
  /// \warning This priority queue cannot be used for concurrent access from
  /// multiple threads.
  /// \tparam T The type of value that the queue holds.
  /// \tparam TContainer to hold the T queue values
  /// \tparam TCompare to use in comparing T values
  //***************************************************************************
  template <typename T, typename TContainer, typename TCompare = etl::less<T> >
  class ipriority_queue
  {
  public:

    typedef T                     value_type;         ///< The type stored in the queue.
    typedef TContainer            container_type;     ///< The container type used for priority queue.
    typedef TCompare              compare_type;       ///< The comparison type.
    typedef T&                    reference;          ///< A reference to the type used in the queue.
    typedef const T&              const_reference;    ///< A const reference to the type used in the queue.
#if ETL_USING_CPP11
    typedef T&&                   rvalue_reference;   ///< An rvalue reference to the type used in the queue.
#endif
    typedef typename TContainer::size_type size_type; ///< The type used for determining the size of the queue.
    typedef typename etl::iterator_traits<typename TContainer::iterator>::difference_type difference_type;

    //*************************************************************************
    /// Gets a reference to the highest priority value in the priority queue.<br>
    /// \return A reference to the highest priority value in the priority queue.
    //*************************************************************************
    reference top()
    {
      return container.front();
    }

    //*************************************************************************
    /// Gets a const reference to the highest priority value in the priority queue.<br>
    /// \return A const reference to the highest priority value in the priority queue.
    //*************************************************************************
    const_reference top() const
    {
      return container.front();
    }

    //*************************************************************************
    /// Adds a value to the queue.
    /// If asserts or exceptions are enabled, throws an etl::priority_queue_full
    /// is the priority queue is already full.
    ///\param value The value to push to the queue.
    //*************************************************************************
    void push(const_reference value)
    {
      ETL_ASSERT(!full(), ETL_ERROR(etl::priority_queue_full));

      // Put element at end
      container.push_back(value);
      // Make elements in container into heap
      etl::push_heap(container.begin(), container.end(), compare);
    }

#if ETL_USING_CPP11
    //*************************************************************************
    /// Moves a value to the queue.
    /// If asserts or exceptions are enabled, throws an etl::priority_queue_full
    /// is the priority queue is already full.
    ///\param value The value to push to the queue.
    //*************************************************************************
    void push(rvalue_reference value)
    {
      ETL_ASSERT(!full(), ETL_ERROR(etl::priority_queue_full));

      // Put element at end
      container.push_back(etl::move(value));
      // Make elements in container into heap
      etl::push_heap(container.begin(), container.end(), compare);
    }
#endif

#if ETL_USING_CPP11 && ETL_NOT_USING_STLPORT && !defined(ETL_PRIORITY_QUEUE_FORCE_CPP03_IMPLEMENTATION)
    //*************************************************************************
    /// Emplaces a value to the queue.
    /// If asserts or exceptions are enabled, throws an etl::priority_queue_full
    /// is the priority queue is already full.
    ///\param value The value to push to the queue.
    //*************************************************************************
    template <typename ... Args>
    void emplace(Args && ... args)
    {
      ETL_ASSERT(!full(), ETL_ERROR(etl::priority_queue_full));

      // Put element at end
      container.emplace_back(etl::forward<Args>(args)...);
      // Make elements in container into heap
      etl::push_heap(container.begin(), container.end(), compare);
    }
#else
    //*************************************************************************
    /// Emplaces a value to the queue.
    /// If asserts or exceptions are enabled, throws an etl::priority_queue_full
    /// is the priority queue is already full.
    ///\param value The value to push to the queue.
    //*************************************************************************
    void emplace()
    {
      ETL_ASSERT(!full(), ETL_ERROR(etl::priority_queue_full));

      // Put element at end
      container.emplace_back();
      // Make elements in container into heap
      etl::push_heap(container.begin(), container.end(), compare);
    }

    //*************************************************************************
    /// Emplaces a value to the queue.
    /// If asserts or exceptions are enabled, throws an etl::priority_queue_full
    /// is the priority queue is already full.
    ///\param value The value to push to the queue.
    //*************************************************************************
    template <typename T1>
    void emplace(const T1& value1)
    {
      ETL_ASSERT(!full(), ETL_ERROR(etl::priority_queue_full));

      // Put element at end
      container.emplace_back(value1);
      // Make elements in container into heap
      etl::push_heap(container.begin(), container.end(), compare);
    }

    //*************************************************************************
    /// Emplaces a value to the queue.
    /// If asserts or exceptions are enabled, throws an etl::priority_queue_full
    /// is the priority queue is already full.
    ///\param value The value to push to the queue.
    //*************************************************************************
    template <typename T1, typename T2>
    void emplace(const T1& value1, const T2& value2)
    {
      ETL_ASSERT(!full(), ETL_ERROR(etl::priority_queue_full));

      // Put element at end
      container.emplace_back(value1, value2);
      // Make elements in container into heap
      etl::push_heap(container.begin(), container.end(), compare);
    }

    //*************************************************************************
    /// Emplaces a value to the queue.
    /// If asserts or exceptions are enabled, throws an etl::priority_queue_full
    /// is the priority queue is already full.
    ///\param value The value to push to the queue.
    //*************************************************************************
    template <typename T1, typename T2, typename T3>
    void emplace(const T1& value1, const T2& value2, const T3& value3)
    {
      ETL_ASSERT(!full(), ETL_ERROR(etl::priority_queue_full));

      // Put element at end
      container.emplace_back(value1, value2, value3);
      // Make elements in container into heap
      etl::push_heap(container.begin(), container.end(), compare);
    }

    //*************************************************************************
    /// Emplaces a value to the queue.
    /// If asserts or exceptions are enabled, throws an etl::priority_queue_full
    /// is the priority queue is already full.
    ///\param value The value to push to the queue.
    //*************************************************************************
    template <typename T1, typename T2, typename T3, typename T4>
    void emplace(const T1& value1, const T2& value2, const T3& value3, const T4& value4)
    {
      ETL_ASSERT(!full(), ETL_ERROR(etl::priority_queue_full));

      // Put element at end
      container.emplace_back(value1, value2, value3, value4);
      // Make elements in container into heap
      etl::push_heap(container.begin(), container.end(), compare);
    }
#endif

    //*************************************************************************
    /// Assigns values to the priority queue.
    /// If asserts or exceptions are enabled, emits priority_queue_full if
    /// priority queue does not have enough free space.
    /// If asserts or exceptions are enabled, emits priority_iterator if the
    /// iterators are reversed.
    ///\param first The iterator to the first element.
    ///\param last  The iterator to the last element + 1.
    //*************************************************************************
    template <typename TIterator>
    void assign(TIterator first, TIterator last)
    {
#if ETL_IS_DEBUG_BUILD
      difference_type d = etl::distance(first, last);
      ETL_ASSERT(d >= 0, ETL_ERROR(etl::priority_queue_iterator));
      ETL_ASSERT(static_cast<size_t>(d) <= max_size(), ETL_ERROR(etl::priority_queue_full));
#endif

      clear();
      container.assign(first, last);
      etl::make_heap(container.begin(), container.end(), compare);
    }

    //*************************************************************************
    /// Removes the oldest value from the back of the priority queue.
    /// Does nothing if the priority queue is already empty.
    //*************************************************************************
    void pop()
    {
      // Move largest element to end
      etl::pop_heap(container.begin(), container.end(), compare);
      // Actually remove largest element at end
      container.pop_back();
    }

    //*************************************************************************
    /// Gets the highest priority value in the priority queue
    /// and assigns it to destination and removes it from the queue.
    //*************************************************************************
    void pop_into(reference destination)
    {
      destination = ETL_MOVE(top());
      pop();
    }

    //*************************************************************************
    /// Returns the current number of items in the priority queue.
    //*************************************************************************
    size_type size() const
    {
      return container.size();
    }

    //*************************************************************************
    /// Returns the maximum number of items that can be queued.
    //*************************************************************************
    size_type max_size() const
    {
      return container.max_size();
    }

    //*************************************************************************
    /// Checks to see if the priority queue is empty.
    /// \return <b>true</b> if the queue is empty, otherwise <b>false</b>
    //*************************************************************************
    bool empty() const
    {
      return container.empty();
    }

    //*************************************************************************
    /// Checks to see if the priority queue is full.
    /// \return <b>true</b> if the priority queue is full, otherwise <b>false</b>
    //*************************************************************************
    bool full() const
    {
      return container.size() == container.max_size();
    }

    //*************************************************************************
    /// Returns the remaining capacity.
    ///\return The remaining capacity.
    //*************************************************************************
    size_type available() const
    {
      return container.max_size() - container.size();
    }

    //*************************************************************************
    /// Clears the queue to the empty state.
    //*************************************************************************
    void clear()
    {
      container.clear();
    }

    //*************************************************************************
    /// Assignment operator.
    //*************************************************************************
    ipriority_queue& operator = (const ipriority_queue& rhs)
    {
      if (&rhs != this)
      {
        clone(rhs);
      }

      return *this;
    }

#if ETL_USING_CPP11
    //*************************************************************************
    /// Move assignment operator.
    //*************************************************************************
    ipriority_queue& operator = (ipriority_queue&& rhs)
    {
      if (&rhs != this)
      {
        clear();
        move(etl::move(rhs));
      }

      return *this;
    }
#endif

  protected:

    //*************************************************************************
    /// Make this a clone of the supplied priority queue
    //*************************************************************************
    void clone(const ipriority_queue& other)
    {
      assign(other.container.cbegin(), other.container.cend());
    }

#if ETL_USING_CPP11
    //*************************************************************************
    /// Make this a moved version of the supplied priority queue
    //*************************************************************************
    void move(ipriority_queue&& other)
    {
      while (!other.empty())
      {
        push(etl::move(other.top()));
        other.pop();
      }
    }
#endif

    //*************************************************************************
    /// The constructor that is called from derived classes.
    //*************************************************************************
    ipriority_queue()
    {
    }

  private:

    // Disable copy construction.
    ipriority_queue(const ipriority_queue&);

    /// The container specified at instantiation of the priority_queue
    TContainer container;

    TCompare compare;
  };

  //***************************************************************************
  ///\ingroup priority_queue
  /// A fixed capacity priority queue.
  /// This queue does not support concurrent access by different threads.
  /// \tparam T    The type this queue should support.
  /// \tparam SIZE The maximum capacity of the queue.
  //***************************************************************************
  template <typename T, const size_t SIZE, typename TContainer = etl::vector<T, SIZE>, typename TCompare = etl::less<typename TContainer::value_type> >
  class priority_queue : public etl::ipriority_queue<T, TContainer, TCompare>
  {
  public:

    typedef typename TContainer::size_type size_type;
    typedef TContainer                     container_type;

    static ETL_CONSTANT size_type MAX_SIZE = size_type(SIZE);

    //*************************************************************************
    /// Default constructor.
    //*************************************************************************
    priority_queue()
      : etl::ipriority_queue<T, TContainer, TCompare>()
    {
    }

    //*************************************************************************
    /// Copy constructor
    //*************************************************************************
    priority_queue(const priority_queue& rhs)
      : etl::ipriority_queue<T, TContainer, TCompare>()
    {
      etl::ipriority_queue<T, TContainer, TCompare>::clone(rhs);
    }

#if ETL_USING_CPP11
    //*************************************************************************
    /// Move constructor
    //*************************************************************************
    priority_queue(priority_queue&& rhs)
      : etl::ipriority_queue<T, TContainer, TCompare>()
    {
      etl::ipriority_queue<T, TContainer, TCompare>::move(etl::move(rhs));
    }
#endif

    //*************************************************************************
    /// Constructor, from an iterator range.
    ///\tparam TIterator The iterator type.
    ///\param first The iterator to the first element.
    ///\param last  The iterator to the last element + 1.
    //*************************************************************************
    template <typename TIterator>
    priority_queue(TIterator first, TIterator last)
      : etl::ipriority_queue<T, TContainer, TCompare>()
    {
      etl::ipriority_queue<T, TContainer, TCompare>::assign(first, last);
    }

    //*************************************************************************
    /// Destructor.
    //*************************************************************************
    ~priority_queue()
    {
      etl::ipriority_queue<T, TContainer, TCompare>::clear();
    }

    //*************************************************************************
    /// Assignment operator.
    //*************************************************************************
    priority_queue& operator = (const priority_queue& rhs)
    {
      if (&rhs != this)
      {
        etl::ipriority_queue<T, TContainer, TCompare>::clone(rhs);
      }

      return *this;
    }

#if ETL_USING_CPP11
    //*************************************************************************
    /// Move assignment operator.
    //*************************************************************************
    priority_queue& operator = (priority_queue&& rhs)
    {
      if (&rhs != this)
      {
        etl::ipriority_queue<T, TContainer, TCompare>::clear();
        etl::ipriority_queue<T, TContainer, TCompare>::move(etl::move(rhs));
      }

      return *this;
    }
#endif
  };

  template <typename T, const size_t SIZE, typename TContainer, typename TCompare>
  ETL_CONSTANT typename priority_queue<T, SIZE, TContainer, TCompare>::size_type priority_queue<T, SIZE, TContainer, TCompare>::MAX_SIZE;
}

#endif