queue.hpp

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/*
 
Copyright 2025 Matthew Tolman
 
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 MTCORE_QUEUE_HPP
#define MTCORE_QUEUE_HPP
 
#include "mtcore/core.hpp"
#include "ring_buffer.hpp"
 
namespace mtcore {
  template<typename T>
  struct Queue {
  private:
    RingBuffer<T> buffer = {};
 
  public:
    Result<void, AllocationError> init(Allocator &alloc, size_t capacity = 10) { return buffer.init(alloc, capacity); }

    Result<void, AllocationError> init(Allocator &alloc, std::initializer_list<T> init, size_t capacity = 10) {
      return buffer.init(alloc, init, capacity);
    }

    void deinit(Allocator &alloc) { buffer.deinit(alloc); }

    [[nodiscard]] bool is_full() const noexcept { return buffer.size() >= buffer.capacity(); }

    [[nodiscard]] bool is_empty() const noexcept { return size() == 0; }

    [[nodiscard]] size_t size() const noexcept { return buffer.size(); }

    [[nodiscard]] size_t capacity() const noexcept { return buffer.capacity(); }
 
    Result<void, AllocationError> shrink_to_fit(Allocator &alloc) { return buffer.shrink_to_fit(alloc); }

    Optional<T> peek() const noexcept {
      ensure(is_initialized(), "Not initialized");
      if (buffer.size() > 0) {
        return buffer.at(0);
      }
      return nullopt;
    }

    Optional<T> pop() noexcept {
      ensure(is_initialized(), "Not initialized");
      mtdefer { ensure(size() <= capacity(), "SIZE MISMATCH"); };
      return buffer.pop_front();
    }

    Result<void, CollectionAddNoAllocationError> push(const T &elem) noexcept {
      ensure(is_initialized(), "Not initialized");
      mtdefer { ensure(size() <= capacity(), "SIZE MISMATCH"); };
      return buffer.push_back(elem);
    }

    Result<void, AllocationError> push(Allocator &alloc, const T &elem) noexcept {
      ensure(is_initialized(), "Not initialized");
      return buffer.push_back(alloc, elem);
    }

    [[nodiscard]] bool is_initialized() const noexcept { return buffer.capacity() > 0; }
  };

  template<typename T, size_t Capacity>
  struct FixedQueue {
  private:
    FixedRingBuffer<T, Capacity> buffer = {};
 
  public:
    Result<void, AllocationError> init() { return buffer.init(); }

    Result<void, AllocationError> init(std::initializer_list<T> init) { return buffer.init(init); }

    [[nodiscard]] size_t size() const noexcept { return buffer.size(); }

    [[nodiscard]] size_t capacity() const noexcept { return Capacity; }

    Optional<T> peek() const noexcept {
      if (buffer.size() > 0) {
        return buffer.at(0);
      }
      return nullopt;
    }

    Optional<T> pop() noexcept {
      mtdefer { ensure(size() <= capacity(), "SIZE MISMATCH"); };
      return buffer.pop_front();
    }

    Result<void, CollectionAddNoAllocationError> push(const T &elem) noexcept {
      mtdefer { ensure(size() <= capacity(), "SIZE MISMATCH"); };
      return buffer.push_back(elem);
    }

    [[nodiscard]] bool is_full() const noexcept { return size() >= Capacity; }

    [[nodiscard]] bool is_empty() const noexcept { return size() == 0; }
  };
}  // namespace mtcore
 
#endif  // MTCORE_QUEUE_HPP