Line data    Source code

       1             : //
       2             : // Copyright 2024 OpenModelViewer Authors
       3             : // 
       4             : // Licensed under the Apache License, Version 2.0 (the "License");
       5             : // you may not use this file except in compliance with the License.
       6             : // You may obtain a copy of the License at
       7             : // 
       8             : //     http://www.apache.org/licenses/LICENSE-2.0
       9             : // 
      10             : // Unless required by applicable law or agreed to in writing, software
      11             : // distributed under the License is distributed on an "AS IS" BASIS,
      12             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      13             : // See the License for the specific language governing permissions and
      14             : // limitations under the License.
      15             : //
      16             : 
      17             : #pragma once
      18             : 
      19             : #include "openmodelviewer/core/id/unique_id.hpp"
      20             : 
      21             : #include <functional>
      22             : 
      23             : namespace openmodelviewer::core::resource
      24             : {
      25             :         /**
      26             :          * @brief Tag type used to distinguish resource IDs from other unique ID types.
      27             :          */
      28             :         struct ResourceTag {};
      29             : 
      30             :         /**
      31             :          * @brief Type alias for unique resource identifiers.
      32             :          *
      33             :          * This ID is unique per resource and is used for identification and comparison.
      34             :          */
      35             :         using ResourceId = openmodelviewer::core::id::UniqueId<ResourceTag>;
      36             : 
      37             :         /**
      38             :          * @brief Lightweight handle used to identify a resource.
      39             :          */
      40             :         struct ResourceHandle
      41             :         {
      42             :                 ResourceId id;  ///< Unique identifier of the resource.
      43             :         };
      44             : 
      45             :         /**
      46             :          * @brief Equality comparison operator.
      47             :          *
      48             :          * Compares two ResourceHandles based on their ResourceId.
      49             :          *
      50             :          * @param lhs Left-hand side ResourceHandle.
      51             :          * @param rhs Right-hand side ResourceHandle.
      52             :          * @return True if both handles refer to the same resource.
      53             :          */
      54          83 :         inline bool operator==(const ResourceHandle& lhs, const ResourceHandle& rhs) noexcept
      55             :         {
      56          83 :                 return lhs.id == rhs.id;
      57             :         }
      58             : 
      59             :         /**
      60             :          * @brief Inequality comparison operator.
      61             :          *
      62             :          * Logical negation of operator==. Returns true if the handles refer to different resources.
      63             :          *
      64             :          * @param lhs Left-hand side ResourceHandle.
      65             :          * @param rhs Right-hand side ResourceHandle.
      66             :          * @return True if the handles refer to different resources.
      67             :          */
      68           3 :         inline bool operator!=(const ResourceHandle& lhs, const ResourceHandle& rhs) noexcept
      69             :         {
      70           3 :                 return !(lhs == rhs);
      71             :         }
      72             : }
      73             : 
      74             : 
      75             : namespace std
      76             : {
      77             :         /**
      78             :          * @brief Hash specialization for ResourceHandle to enable use in unordered containers.
      79             :          *
      80             :          * This hash implementation delegates to the hash of the underlying ResourceId.
      81             :          * It ensures ResourceHandle can be used as a key in std::unordered_map or std::unordered_set.
      82             :          */
      83             :         template<>
      84             :         struct hash<openmodelviewer::core::resource::ResourceHandle>
      85             :         {
      86         182 :                 inline std::size_t operator()(const openmodelviewer::core::resource::ResourceHandle& handle) const noexcept
      87             :                 {
      88         182 :                         return std::hash<openmodelviewer::core::resource::ResourceId>{}(handle.id);
      89             :                 }
      90             :         };
      91             : } // namespace openmodelviewer::core::async