ItemEnumeratorBase.h

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2026 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
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/* ItemEnumeratorBase.h                                        (C) 2000-2024 */
/*                                                                           */
/* Base class for enumerators over mesh entities.                            */
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#ifndef ARCANE_CORE_ITEMENUMERATORBASE_H
#define ARCANE_CORE_ITEMENUMERATORBASE_H
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#include "arcane/core/ItemInternalEnumerator.h"
#include "arcane/core/Item.h"
 
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namespace Arcane
{
 
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class ItemEnumeratorCS;
class ItemGroupImpl;
 
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/*!
 * \brief Represents an index of an enumeration over an entity.
 */
class ItemEnumeratorIndex
{
 public:
 
  ItemEnumeratorIndex() = default;
  constexpr ARCCORE_HOST_DEVICE explicit ItemEnumeratorIndex(Int32 index)
  : m_index(index)
  {}
  constexpr ARCCORE_HOST_DEVICE Int32 index() const { return m_index; }
  constexpr ARCCORE_HOST_DEVICE Int32 asInt32() const { return m_index; }
 
 private:
 
  Int32 m_index = -1;
};
 
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/*!
 * \brief Represents an index of an enumeration over an entity \a ItemType.
 */
template <typename ItemType>
class ItemEnumeratorIndexT
: public ItemEnumeratorIndex
{
 public:
 
  ItemEnumeratorIndexT() = default;
  constexpr ARCCORE_HOST_DEVICE explicit ItemEnumeratorIndexT(Int32 index)
  : ItemEnumeratorIndex(index)
  {}
};
 
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/*!
 * \brief Base class for enumerators over a list of entities.
 *
 * Instances of this class are created either via ItemEnumerator or via ItemEnumeratorT.
 */
class ItemEnumeratorBase
{
 private:
 
  using ItemInternalPtr = ItemInternal*;
 
 protected:
 
  ItemEnumeratorBase() = default;
  ItemEnumeratorBase(const ItemInternalPtr*, const Int32* local_ids, Integer n, const ItemGroupImpl* agroup)
  // TODO: manage offset
  : m_view(local_ids, n, 0)
  , m_group_impl(agroup)
  {}
  explicit ItemEnumeratorBase(const Int32ConstArrayView& local_ids)
  // TODO: manage offset
  : m_view(local_ids, 0)
  , m_group_impl(nullptr)
  {}
  ItemEnumeratorBase(const Int32ConstArrayView& local_ids, const ItemGroupImpl* agroup)
  // TODO: manage offset
  : m_view(local_ids, 0)
  , m_group_impl(agroup)
  {}
  // TODO: To be removed
  ItemEnumeratorBase(const ItemInternalVectorView& view, const ItemGroupImpl* agroup)
  : m_view(view.localIds(), view.m_local_id_offset)
  , m_group_impl(agroup)
  {}
  ItemEnumeratorBase(const ItemVectorView& rhs)
  : m_view(rhs.localIds(), rhs._localIdOffset())
  {}
  template <int E> ItemEnumeratorBase(const ItemConnectedListView<E>& rhs)
  : m_view(rhs._localIds(), rhs._localIdOffset())
  {}
 
  ItemEnumeratorBase(const ItemEnumerator& rhs);
 
 public:
 
  //! Increments the enumerator index
  constexpr void operator++() { ++m_index; }
  constexpr bool operator()() { return m_index < m_view.m_size; }
 
  //! True if the end of the enumerator has not been reached (index()<count())
  constexpr bool hasNext() { return m_index < m_view.m_size; }
 
  //! Number of elements in the enumerator
  constexpr Integer count() const { return m_view.m_size; }
 
  //! Current index of the enumerator
  constexpr Integer index() const { return m_index; }
 
  //! localId() of the current entity.
  Int32 itemLocalId() const { return m_view.localId(m_index); }
 
  //! localId() of the current entity.
  Int32 localId() const { return m_view.localId(m_index); }
 
  /*!
   * \internal
   * \brief Local indices.
   */
  ARCANE_DEPRECATED_REASON("Y2022: This method is internal to Arcane")
  constexpr const Int32* unguardedLocalIds() const { return m_view.m_local_ids; }
 
  /*!
   * \brief Underlying group if it exists (nullptr otherwise).
   *
   * \brief This aims to test that accesses via this enumerator on a partial object are legitimate.
   */
  constexpr const ItemGroupImpl* group() const { return m_group_impl; }
 
  static constexpr int version() { return 3; }
 
 protected:
 
  impl::ItemLocalIdListContainerView m_view;
  Int32 m_index = 0;
  const ItemGroupImpl* m_group_impl = nullptr; // could be removed in release mode if necessary
 
 protected:
 
  //! Constructor only used by fromItemEnumerator()
  ItemEnumeratorBase(const ItemEnumerator& rhs, bool);
 
  ItemEnumeratorBase(const impl::ItemLocalIdListContainerView& view, Int32 index, const ItemGroupImpl* agroup)
  : m_view(view)
  , m_index(index)
  , m_group_impl(agroup)
  {
  }
 
  explicit ItemEnumeratorBase(const impl::ItemLocalIdListContainerView& view)
  : m_view(view)
  {
  }
 
  ItemInternal* _internal(ItemSharedInfo* si) const
  {
    return si->m_items_internal[m_view.localId(m_index)];
  }
  constexpr const ItemInternalPtr* _unguardedItems(ItemSharedInfo* si) const
  {
    return si->m_items_internal.data();
  }
 
 private:
};
 
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/*!
 * \brief Base class for enumerators over a list of entities.
 *
 * Instances of this class are created either via ItemEnumerator or via ItemEnumeratorT.
 */
template <typename ItemType>
class ItemEnumeratorBaseT
: public ItemEnumeratorBase
{
  friend class SimdItemEnumeratorBase;
 
 private:
 
  using ItemInternalPtr = ItemInternal*;
  using LocalIdType = typename ItemType::LocalIdType;
  using BaseClass = ItemEnumeratorBase;
 
 protected:
 
  ItemEnumeratorBaseT()
  : BaseClass()
  , m_item(NULL_ITEM_LOCAL_ID, ItemSharedInfo::nullInstance())
  {}
  // TODO: manage offset
  ItemEnumeratorBaseT(ItemSharedInfo* shared_info, const Int32ConstArrayView& local_ids)
  : BaseClass(local_ids)
  , m_item(NULL_ITEM_LOCAL_ID, shared_info)
  {}
  // TODO: manage offset
  ItemEnumeratorBaseT(const ItemInfoListView& items, const Int32ConstArrayView& local_ids, const ItemGroupImpl* agroup)
  : BaseClass(local_ids, agroup)
  , m_item(NULL_ITEM_LOCAL_ID, items.m_item_shared_info)
  {}
  ItemEnumeratorBaseT(const ItemInternalVectorView& view, const ItemGroupImpl* agroup)
  : BaseClass(view, agroup)
  , m_item(NULL_ITEM_LOCAL_ID, view.m_shared_info)
  {}
  ItemEnumeratorBaseT(const ItemVectorView& rhs)
  : ItemEnumeratorBaseT((const ItemInternalVectorView&)rhs, nullptr)
  {}
  ItemEnumeratorBaseT(const ItemVectorViewT<ItemType>& rhs)
  : ItemEnumeratorBaseT((const ItemInternalVectorView&)rhs, nullptr)
  {}
 
  ItemEnumeratorBaseT(const ItemEnumerator& rhs);
  ItemEnumeratorBaseT(const impl::ItemIndexedListView<DynExtent>& view)
  : ItemEnumeratorBaseT(view.m_shared_info, view.constLocalIds())
  {}
 
  ItemEnumeratorBaseT(const ItemConnectedListViewT<ItemType>& rhs)
  : BaseClass(rhs)
  , m_item(NULL_ITEM_LOCAL_ID, rhs.m_shared_info)
  {}
 
  ItemEnumeratorBaseT(ItemSharedInfo* si, const impl::ItemLocalIdListContainerView& view)
  : BaseClass(view)
  , m_item(NULL_ITEM_LOCAL_ID, si)
  {
  }
 
 protected:
 
  // TODO: to be removed
  ItemEnumeratorBaseT(const ItemInternalPtr* items, const Int32* local_ids, Integer n, const ItemGroupImpl* agroup)
  : BaseClass(items, local_ids, n, agroup)
  {
    _init(items);
  }
  // TODO: to be removed
  ItemEnumeratorBaseT(const ItemInternalArrayView& items, const Int32ConstArrayView& local_ids, const ItemGroupImpl* agroup)
  : BaseClass(local_ids, agroup)
  {
    _init(items.data());
  }
  // TODO: to be removed
  ItemEnumeratorBaseT(const ItemInternalEnumerator& rhs);
 
 public:
 
  /*!
   * \internal
   * \brief List of ItemInternal.
   * NOTE: In Arcane, this method is used only for the C# wrapper. To be removed later.
   */
  ARCANE_DEPRECATED_REASON("Y2022: This method is internal to Arcane")
  constexpr const ItemInternalPtr* unguardedItems() const { return _unguardedItems(m_item.m_shared_info); }
 
  /*!
   * \internal
   * \brief Internal part (for internal use only).
   */
  ARCANE_DEPRECATED_REASON("Y2022: This method is internal to Arcane")
  constexpr ItemInternal* internal() const { return _internal(m_item.m_shared_info); }
 
 public:
 
  constexpr ItemType operator*() const
  {
    m_item.m_local_id = m_view.localId(m_index);
    return m_item;
  }
  constexpr const ItemType* operator->() const
  {
    m_item.m_local_id = m_view.localId(m_index);
    return &m_item;
  }
 
  constexpr LocalIdType asItemLocalId() const
  {
    return LocalIdType{ m_view.localId(m_index) };
  }
 
  constexpr operator LocalIdType() const
  {
    return LocalIdType{ m_view.localId(m_index) };
  }
 
  ItemEnumerator toItemEnumerator() const;
 
 public:
 
  impl::ItemBase _internalItemBase() const { return m_item.itemBase(); }
 
 protected:
 
  mutable ItemType m_item = ItemType(NULL_ITEM_LOCAL_ID, nullptr);
 
 protected:
 
  //! Constructor only used by fromItemEnumerator()
  ItemEnumeratorBaseT(const ItemEnumerator& rhs, bool);
 
  ItemEnumeratorBaseT(const impl::ItemLocalIdListContainerView& view, Int32 index,
                      const ItemGroupImpl* agroup, Item item_base)
  : ItemEnumeratorBase(view, index, agroup)
  , m_item(item_base)
  {
  }
 
  void _init(const ItemInternalPtr* items)
  {
    m_item.m_shared_info = ItemInternalCompatibility::_getSharedInfo(items, count());
  }
};
 
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} // End namespace Arcane
 
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#endif