sarray_soa_impl.h

#pragma once
#include "gaia/config/config.h"
 
#include <cstddef>
#include <new>
#include <tuple>
#include <type_traits>
#include <utility>
 
#include "gaia/core/iterator.h"
#include "gaia/core/utility.h"
#include "gaia/mem/data_layout_policy.h"
#include "gaia/mem/mem_utils.h"
#include "gaia/mem/raw_data_holder.h"
 
namespace gaia {
  namespace cnt {
    namespace sarr_soa_detail {
      using difference_type = uint32_t;
      using size_type = uint32_t;
    } // namespace sarr_soa_detail
 
    template <typename T>
    struct sarr_soa_iterator {
      using value_type = T;
      // using pointer = T*; not supported
      // using reference = T&; not supported
      using difference_type = sarr_soa_detail::difference_type;
      using size_type = sarr_soa_detail::size_type;
 
      using iterator = sarr_soa_iterator;
      using iterator_category = core::random_access_iterator_tag;
 
    private:
      uint8_t* m_ptr;
      uint32_t m_cnt;
      uint32_t m_idx;
 
    public:
      sarr_soa_iterator(uint8_t* ptr, uint32_t cnt, uint32_t idx): m_ptr(ptr), m_cnt(cnt), m_idx(idx) {}
 
      T operator*() const {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::get({m_ptr, m_cnt}, m_idx);
      }
      T operator->() const {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::get({m_ptr, m_cnt}, m_idx);
      }
      iterator operator[](size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
 
      iterator& operator+=(size_type diff) {
        m_idx += diff;
        return *this;
      }
      iterator& operator-=(size_type diff) {
        m_idx -= diff;
        return *this;
      }
      iterator& operator++() {
        ++m_idx;
        return *this;
      }
      iterator operator++(int) {
        iterator temp(*this);
        ++*this;
        return temp;
      }
      iterator& operator--() {
        --m_idx;
        return *this;
      }
      iterator operator--(int) {
        iterator temp(*this);
        --*this;
        return temp;
      }
 
      iterator operator+(size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
      iterator operator-(size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
      difference_type operator-(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return (difference_type)(m_idx - other.m_idx);
      }
 
      GAIA_NODISCARD bool operator==(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx == other.m_idx;
      }
      GAIA_NODISCARD bool operator!=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx != other.m_idx;
      }
      GAIA_NODISCARD bool operator>(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx > other.m_idx;
      }
      GAIA_NODISCARD bool operator>=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx >= other.m_idx;
      }
      GAIA_NODISCARD bool operator<(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx < other.m_idx;
      }
      GAIA_NODISCARD bool operator<=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx <= other.m_idx;
      }
    };
 
    template <typename T>
    struct const_sarr_soa_iterator {
      using value_type = T;
      // using pointer = T*; not supported
      // using reference = T&; not supported
      using difference_type = sarr_soa_detail::difference_type;
      using size_type = sarr_soa_detail::size_type;
 
      using iterator = const_sarr_soa_iterator;
      using iterator_category = core::random_access_iterator_tag;
 
    private:
      const uint8_t* m_ptr;
      uint32_t m_cnt;
      uint32_t m_idx;
 
    public:
      const_sarr_soa_iterator(const uint8_t* ptr, uint32_t cnt, uint32_t idx): m_ptr(ptr), m_cnt(cnt), m_idx(idx) {}
 
      T operator*() const {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::get({m_ptr, m_cnt}, m_idx);
      }
      T operator->() const {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::get({m_ptr, m_cnt}, m_idx);
      }
      iterator operator[](size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
 
      iterator& operator+=(size_type diff) {
        m_idx += diff;
        return *this;
      }
      iterator& operator-=(size_type diff) {
        m_idx -= diff;
        return *this;
      }
      iterator& operator++() {
        ++m_idx;
        return *this;
      }
      iterator operator++(int) {
        iterator temp(*this);
        ++*this;
        return temp;
      }
      iterator& operator--() {
        --m_idx;
        return *this;
      }
      iterator operator--(int) {
        iterator temp(*this);
        --*this;
        return temp;
      }
 
      iterator operator+(size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
      iterator operator-(size_type offset) const {
        return iterator(m_ptr, m_cnt, m_idx + offset);
      }
      difference_type operator-(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return (difference_type)(m_idx - other.m_idx);
      }
 
      GAIA_NODISCARD bool operator==(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx == other.m_idx;
      }
      GAIA_NODISCARD bool operator!=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx != other.m_idx;
      }
      GAIA_NODISCARD bool operator>(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx > other.m_idx;
      }
      GAIA_NODISCARD bool operator>=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx >= other.m_idx;
      }
      GAIA_NODISCARD bool operator<(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx < other.m_idx;
      }
      GAIA_NODISCARD bool operator<=(const iterator& other) const {
        GAIA_ASSERT(m_ptr == other.m_ptr);
        return m_idx <= other.m_idx;
      }
    };
 
    template <typename T, sarr_soa_detail::size_type N>
    class sarr_soa {
      static_assert(mem::is_soa_layout_v<T>, "sarr_soa can be used only with soa types");
 
    public:
      static_assert(N > 0);
 
      using value_type = T;
      using reference = T&;
      using const_reference = const T&;
      using pointer = T*;
      using const_pointer = T*;
      using view_policy = mem::data_view_policy_soa<T::gaia_Data_Layout, T>;
      using difference_type = sarr_soa_detail::difference_type;
      using size_type = sarr_soa_detail::size_type;
 
      using iterator = sarr_soa_iterator<T>;
      using const_iterator = const_sarr_soa_iterator<T>;
      using iterator_category = core::random_access_iterator_tag;
 
      static constexpr size_type extent = N;
      static constexpr uint32_t allocated_bytes = view_policy::get_min_byte_size(0, N);
 
      mem::raw_data_holder<T, allocated_bytes> m_data;
 
      constexpr sarr_soa() noexcept = default;
 
      constexpr sarr_soa(core::zero_t) noexcept {
        // explicit zeroing
        for (auto i = (size_type)0; i < extent; ++i)
          operator[](i) = {};
      }
 
      ~sarr_soa() = default;
 
      template <typename InputIt>
      constexpr sarr_soa(InputIt first, InputIt last) noexcept {
        const auto count = (size_type)core::distance(first, last);
 
        if constexpr (std::is_pointer_v<InputIt>) {
          for (size_type i = 0; i < count; ++i)
            operator[](i) = first[i];
        } else if constexpr (std::is_same_v<typename InputIt::iterator_category, core::random_access_iterator_tag>) {
          for (size_type i = 0; i < count; ++i)
            operator[](i) = *(first[i]);
        } else {
          size_type i = 0;
          for (auto it = first; it != last; ++it)
            operator[](++i) = *it;
        }
      }
 
      constexpr sarr_soa(std::initializer_list<T> il): sarr_soa(il.begin(), il.end()) {}
 
      constexpr sarr_soa(const sarr_soa& other): sarr_soa(other.begin(), other.end()) {}
 
      constexpr sarr_soa(sarr_soa&& other) noexcept {
        GAIA_ASSERT(core::addressof(other) != this);
 
        mem::move_elements<T, true>((uint8_t*)m_data, (uint8_t*)other.m_data, other.size(), 0, extent, other.extent);
      }
 
      sarr_soa& operator=(std::initializer_list<T> il) {
        *this = sarr_soa(il.begin(), il.end());
        return *this;
      }
 
      constexpr sarr_soa& operator=(const sarr_soa& other) {
        GAIA_ASSERT(core::addressof(other) != this);
 
        mem::copy_elements<T, true>(
            GAIA_ACC((uint8_t*)&m_data[0]), GAIA_ACC((const uint8_t*)&other.m_data[0]), other.size(), 0, extent,
            other.extent);
 
        return *this;
      }
 
      constexpr sarr_soa& operator=(sarr_soa&& other) noexcept {
        GAIA_ASSERT(core::addressof(other) != this);
 
        mem::move_elements<T, true>(
            GAIA_ACC((uint8_t*)&m_data[0]), GAIA_ACC((uint8_t*)&other.m_data[0]), other.size(), 0, extent,
            other.extent);
 
        return *this;
      }
 
      GAIA_CLANG_WARNING_PUSH()
      // Memory is aligned so we can silence this warning
      GAIA_CLANG_WARNING_DISABLE("-Wcast-align")
 
      GAIA_NODISCARD constexpr pointer data() noexcept {
        return GAIA_ACC((pointer)&m_data[0]);
      }
 
      GAIA_NODISCARD constexpr const_pointer data() const noexcept {
        return GAIA_ACC((const_pointer)&m_data[0]);
      }
 
      GAIA_NODISCARD constexpr decltype(auto) operator[](size_type pos) noexcept {
        GAIA_ASSERT(pos < size());
        return view_policy::set({GAIA_ACC((typename view_policy::TargetCastType) & m_data[0]), extent}, pos);
      }
 
      GAIA_NODISCARD constexpr decltype(auto) operator[](size_type pos) const noexcept {
        GAIA_ASSERT(pos < size());
        return view_policy::get({GAIA_ACC((typename view_policy::TargetCastType) & m_data[0]), extent}, pos);
      }
 
      GAIA_CLANG_WARNING_POP()
 
      GAIA_NODISCARD constexpr size_type size() const noexcept {
        return N;
      }
 
      GAIA_NODISCARD constexpr bool empty() const noexcept {
        return begin() == end();
      }
 
      GAIA_NODISCARD constexpr size_type capacity() const noexcept {
        return N;
      }
 
      GAIA_NODISCARD constexpr size_type max_size() const noexcept {
        return N;
      }
 
      GAIA_NODISCARD constexpr decltype(auto) front() noexcept {
        return *begin();
      }
 
      GAIA_NODISCARD constexpr decltype(auto) front() const noexcept {
        return *begin();
      }
 
      GAIA_NODISCARD constexpr decltype(auto) back() noexcept {
        return (operator[])(N - 1);
      }
 
      GAIA_NODISCARD constexpr decltype(auto) back() const noexcept {
        return operator[](N - 1);
      }
 
      GAIA_NODISCARD constexpr auto begin() noexcept {
        return iterator(GAIA_ACC(&m_data[0]), extent, 0);
      }
 
      GAIA_NODISCARD constexpr auto begin() const noexcept {
        return const_iterator(GAIA_ACC(&m_data[0]), extent, 0);
      }
 
      GAIA_NODISCARD constexpr auto cbegin() const noexcept {
        return const_iterator(GAIA_ACC(&m_data[0]), extent, 0);
      }
 
      GAIA_NODISCARD constexpr auto rbegin() noexcept {
        return iterator(GAIA_ACC(&m_data[0]), extent, size() - 1);
      }
 
      GAIA_NODISCARD constexpr auto rbegin() const noexcept {
        return const_iterator(m_data, extent, size() - 1);
      }
 
      GAIA_NODISCARD constexpr auto crbegin() const noexcept {
        return const_iterator(m_data, extent, size() - 1);
      }
 
      GAIA_NODISCARD constexpr auto end() noexcept {
        return iterator(GAIA_ACC(&m_data[0]), extent, size());
      }
 
      GAIA_NODISCARD constexpr auto end() const noexcept {
        return const_iterator(GAIA_ACC(&m_data[0]), extent, size());
      }
 
      GAIA_NODISCARD constexpr auto cend() const noexcept {
        return const_iterator(GAIA_ACC(&m_data[0]), extent, size());
      }
 
      GAIA_NODISCARD constexpr auto rend() noexcept {
        return iterator(GAIA_ACC(&m_data[0]), extent, -1);
      }
 
      GAIA_NODISCARD constexpr auto rend() const noexcept {
        return const_iterator(GAIA_ACC(&m_data[0]), extent, -1);
      }
 
      GAIA_NODISCARD constexpr auto crend() const noexcept {
        return const_iterator(GAIA_ACC(&m_data[0]), extent, -1);
      }
 
      GAIA_NODISCARD constexpr bool operator==(const sarr_soa& other) const {
        for (size_type i = 0; i < N; ++i)
          if (!(operator[](i) == other[i]))
            return false;
        return true;
      }
 
      GAIA_NODISCARD constexpr bool operator!=(const sarr_soa& other) const {
        return !operator==(other);
      }
 
      template <size_t Item>
      auto view_mut() noexcept {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::template set<Item>(
            std::span<uint8_t>{GAIA_ACC((uint8_t*)&m_data[0]), extent});
      }
 
      template <size_t Item>
      auto view() const noexcept {
        return mem::data_view_policy<T::gaia_Data_Layout, T>::template get<Item>(
            std::span<const uint8_t>{GAIA_ACC((const uint8_t*)&m_data[0]), extent});
      }
    };
 
    namespace detail {
      template <typename T, uint32_t N, uint32_t... I>
      constexpr sarr_soa<std::remove_cv_t<T>, N> to_array_impl(T (&a)[N], std::index_sequence<I...> /*no_name*/) {
        return {{a[I]...}};
      }
    } // namespace detail
 
    template <typename T, uint32_t N>
    constexpr sarr_soa<std::remove_cv_t<T>, N> to_array(T (&a)[N]) {
      return detail::to_array_impl(a, std::make_index_sequence<N>{});
    }
 
    template <typename T, typename... U>
    sarr_soa(T, U...) -> sarr_soa<T, 1 + (uint32_t)sizeof...(U)>;
 
  } // namespace cnt
} // namespace gaia
 
namespace std {
  template <typename T, uint32_t N>
  struct tuple_size<gaia::cnt::sarr_soa<T, N>>: std::integral_constant<uint32_t, N> {};
 
  template <size_t I, typename T, uint32_t N>
  struct tuple_element<I, gaia::cnt::sarr_soa<T, N>> {
    using type = T;
  };
} // namespace std