tpl_arrayQueue.H

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/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
 
#ifndef TPL_ARRAYQUEUE_H
#define TPL_ARRAYQUEUE_H
 
#include <ahAssert.H>
#include <ahDefs.H>
#include <htlist.H>
#include <ah-dry.H>
#include <ah-args-ctor.H>
#include <tpl_dynDlist.H>
#include <tpl_memArray.H>
 
namespace Aleph {
 
template <typename T>
class ArrayQueue : public MemArray<T>,
                   public LocateFunctions<ArrayQueue<T>, T>,
                   public FunctionalMethods<ArrayQueue<T>, T>,
                   public GenericKeys<ArrayQueue<T>, T>,
                   public EqualToMethod<ArrayQueue<T>>,
                   public StlAlephIterator<ArrayQueue<T>>
{
private:
  size_t front_index;  // items are extracted from this point
  size_t rear_index;   // new item is inserted by this point
 
  void increase_index(size_t &i, const size_t inc = 1) const noexcept
  {
    i += inc;
    i %= this->dim;
  }
 
  T &rear_item(const size_t i = 0) const noexcept
  {
    const size_t offset = (rear_index + this->dim - (i + 1) % this->dim) % this->dim;
    return this->access(offset);
  }
 
  void recenter_indices() noexcept
  {
    front_index = 0;
    rear_index = this->n;
  }
 
public:
  void swap(ArrayQueue &q) noexcept
  {
    this->MemArray<T>::swap(q);
    std::swap(front_index, q.front_index);
    std::swap(rear_index, q.rear_index);
  }
 
  ArrayQueue(const size_t sz = 8) : MemArray<T>(sz), front_index(0), rear_index(0)
  {
    // empty
  }
 
  ArrayQueue(const ArrayQueue &q)
    : MemArray<T>(q), front_index(q.front_index), rear_index(q.rear_index)
  {}
 
  ArrayQueue(ArrayQueue &&q) noexcept
    : MemArray<T>(std::move(q)), front_index(q.front_index), rear_index(q.rear_index)
  {
    q.front_index = 0;
    q.rear_index = 0;
  }
 
  Special_Ctors(ArrayQueue, T);
 
  ArrayQueue &operator=(const ArrayQueue &q)
  {
    if (this == &q)
      return *this;
 
    static_cast<MemArray<T> &>(*this) = q;
 
    front_index = q.front_index;
    rear_index = q.rear_index;
 
    return *this;
  }
 
  ArrayQueue &operator=(ArrayQueue &&q) noexcept
  {
    std::swap(front_index, q.front_index);
    std::swap(rear_index, q.rear_index);
    static_cast<MemArray<T> *>(this)->swap(q);
    return *this;
  }
 
private:
  T &complete_put() noexcept
  {
    T &ret_val = this->access(rear_index);
    increase_index(rear_index);
    ++this->n;
    return ret_val;
  }
 
public:
  T &put(const T &item)
  {
    if (this->expand(front_index))
      recenter_indices();
    this->access(rear_index) = item;
    return complete_put();
  }
 
  T &put(T &&item)
  {
    if (this->expand(front_index))
      recenter_indices();
    this->access(rear_index) = std::forward<T>(item);
    return complete_put();
  }
 
  T &append(const T &item)
  {
    return put(item);
  }
 
  T &append(T &&item)
  {
    return put(std::forward<T>(item));
  }
 
  T &insert(const T &item)
  {
    return put(item);
  }
 
  T &insert(T &&item)
  {
    return put(std::forward<T>(item));
  }
 
  T &putn(const size_t sz)
  {
    const size_t max_sz = 2 * this->dim - this->n;
    ah_overflow_error_if(sz > max_sz) << "Maximum putn size reached";
 
    size_t remaining = sz;
    while (remaining > 0)
      {
        const size_t available = this->dim - this->n;
        if (available == 0)
          {
            if (this->expand(front_index))
              recenter_indices();
            continue;
          }
 
        const size_t delta = remaining < available ? remaining : available;
        increase_index(rear_index, delta);
        this->n += delta;
        remaining -= delta;
      }
 
    return rear_item();
  }
 
  T get()
  {
    ah_underflow_error_if(this->n == 0) << "queue is empty";
 
    T ret_val = std::move(this->access(front_index));
    --this->n;
    increase_index(front_index);
 
    if (this->contract(front_index))
      recenter_indices();
 
    return ret_val;
  }
 
  T &getn(const size_t i)
  {
    ah_underflow_error_if(i >= this->n) << "queue is empty";
 
    this->n -= i;
    increase_index(front_index, i);
 
    if (this->contract(front_index))
      recenter_indices();
 
    return this->access(front_index);
  }
 
  T &front(const size_t i = 0) const
  {
    ah_range_error_if(i >= this->n) << "index of front out of range";
 
    return this->access((front_index + i) % this->dim);
  }
 
  T &rear(const size_t i = 0) const
  {
    ah_range_error_if(i >= this->n) << "index of rear out of range";
 
    return rear_item(i);
  }
 
  template <class Operation>
  bool traverse(Operation &operation)
  {
    if (this->n == 0)
      return true;
 
    for (size_t i = 0, idx = front_index; i < this->n; increase_index(idx), ++i)
      if (not operation(this->access(idx)))
        return false;
    return true;
  }
 
  template <class Operation>
  bool traverse(Operation &operation) const
  {
    return const_cast<ArrayQueue *>(this)->traverse(operation);
  }
 
  template <class Operation>
  bool traverse(Operation &&operation) const
  {
    return traverse<Operation>(operation);
  }
 
  template <class Operation>
  bool traverse(Operation &&operation)
  {
    return traverse<Operation>(operation);
  }
 
  struct Iterator : public MemArray<T>::Iterator
  {
    using Base = typename MemArray<T>::Iterator;
    using Base::Base;
    using Set_Type = ArrayQueue;
 
    Iterator(const ArrayQueue &q)
      : Base(q.ptr, q.dim, q.n, q.front_index, (q.rear_index - 1) % q.dim)
    {}
  };
};
 
template <typename T>
class FixedQueue : public LocateFunctions<FixedQueue<T>, T>,
                   public FunctionalMethods<FixedQueue<T>, T>,
                   public GenericKeys<FixedQueue<T>, T>,
                   public EqualToMethod<FixedQueue<T>>,
                   public StlAlephIterator<FixedQueue<T>>
{
  size_t dim;
  T *array;
  size_t front_index; /* index of oldest inserted item */
  size_t rear_index;
  size_t mask;
  size_t num_items;
 
  void increase_index(size_t &i, const size_t inc = 1) const noexcept
  {
    assert(((i + inc) % dim) == ((i + inc) & mask));
 
    i += inc;
    i &= mask;
  }
 
  T &rear_item(const size_t i = 0) const noexcept
  {
    assert(static_cast<size_t>((rear_index - i - 1) & mask) == (rear_index - i - 1) % dim);
 
    return array[static_cast<size_t>((rear_index - i - 1) & mask)];
  }
 
public:
  using Item_Type = T;
 
  void swap(FixedQueue &q) noexcept
  {
    std::swap(dim, q.dim);
    std::swap(array, q.array);
    std::swap(front_index, q.front_index);
    std::swap(rear_index, q.rear_index);
    std::swap(mask, q.mask);
    std::swap(num_items, q.num_items);
  }
 
  void empty() noexcept
  {
    front_index = rear_index = num_items = 0;
  }
 
  void clear() noexcept
  {
    empty();
  }
 
  FixedQueue(size_t d = 1024)
    // Don't change the default value because you would risk of
    // breaking the tests
    : dim(0), array(nullptr), front_index(0), rear_index(0), mask(0), num_items(0)
  {
    size_t k = log2(d);
    dim = is_power_of_2(d) ? d : 1 << ++k;
    mask = dim - 1;
    array = new T[dim];
  }
 
  ~FixedQueue()
  {
    if (array != nullptr)
      delete[] array;
  }
 
  FixedQueue(const FixedQueue &q)
    : dim(q.dim), array(new T[dim]), front_index(q.front_index), rear_index(q.rear_index),
      mask(q.mask), num_items(q.num_items)
  {
    for (size_t i = front_index; i != rear_index; ++i)
      array[i] = q.array[i];
  }
 
  FixedQueue(FixedQueue &&q) noexcept : FixedQueue()
  {
    swap(q);
  }
 
  Special_Ctors(FixedQueue, T);
 
  FixedQueue &operator=(const FixedQueue &q)
  {
    if (this == &q)
      return *this;
 
    FixedQueue tmp(q);
    swap(tmp);
    return *this;
  }
 
  FixedQueue &operator=(FixedQueue &&q) noexcept
  {
    swap(q);
    return *this;
  }
 
  T &put(const T &item) noexcept
  {
    assert(num_items < dim);
    array[rear_index] = item;
    T &ret_val = array[rear_index];
    increase_index(rear_index);
    num_items++;
    return ret_val;
  }
 
  T &put(T &&item) noexcept
  {
    assert(num_items < dim);
    array[rear_index] = std::forward<T>(item);
    T &ret_val = array[rear_index];
    increase_index(rear_index);
    num_items++;
    return ret_val;
  }
 
  T &append(const T &item) noexcept
  {
    return put(item);
  }
 
  T &append(T &&item) noexcept
  {
    return put(std::forward<T>(item));
  }
 
  T &insert(const T &item) noexcept
  {
    return put(item);
  }
 
  T &insert(T &&item) noexcept
  {
    return put(std::forward<T>(item));
  }
 
  T &putn(const size_t n) noexcept
  {
    assert(num_items + n < dim);
    increase_index(rear_index, n);
    num_items += n;
    return rear_item();
  }
 
  T get() noexcept
  {
    assert(num_items > 0);
    num_items--;
    T ret_val = std::move(array[front_index]);
    increase_index(front_index);
    return ret_val;
  }
 
  T &getn(const size_t n) noexcept
  {
    assert(num_items >= n);
    num_items -= n;
    increase_index(front_index, n);
    return array[front_index];
  }
 
  T &front(const size_t i = 0) const noexcept
  {
    assert(i < num_items);
    return array[front_index + i];
  }
 
  T &rear(const size_t i = 0) const noexcept
  {
    assert(i < num_items);
    return rear_item(i);
  }
 
  [[nodiscard]] constexpr size_t size() const noexcept
  {
    return num_items;
  }
 
  [[nodiscard]] constexpr bool is_empty() const noexcept
  {
    return num_items == 0;
  }
 
  [[nodiscard]] constexpr size_t capacity() const noexcept
  {
    return dim;
  }
 
  template <class Operation>
  bool traverse(Operation &operation)
  {
    if (num_items == 0)
      return true;
    for (size_t i = 0, idx = front_index; i < num_items; increase_index(idx), ++i)
      if (not operation(array[idx]))
        return false;
    return true;
  }
 
  template <class Operation>
  bool traverse(Operation &operation) const
  {
    return const_cast<FixedQueue *>(this)->traverse(operation);
  }
 
  template <class Operation>
  bool traverse(Operation &&operation = Operation()) const
  {
    return traverse<Operation>(operation);
  }
 
  template <class Operation>
  bool traverse(Operation &&operation = Operation())
  {
    return traverse<Operation>(operation);
  }
 
  struct Iterator : public MemArray<T>::Iterator
  {
    using Base = typename MemArray<T>::Iterator;
    using Base::Base;
    using Set_Type = FixedQueue;
 
    Iterator(const FixedQueue &q) noexcept
      : Base(q.array, q.dim, q.num_items, q.front_index, (q.rear_index - 1) % q.dim)
    {}
  };
};
 
}  // end namespace Aleph
 
#endif /* TPL_ARRAYQUEUE_H */