TypedElementIndexHasher.inl

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "Hash/CityHash.h"
#include "UObject/TopLevelAssetPath.h"
 
namespace UE::Editor::DataStorage
{
    template<typename T>
    IndexHash GenerateIndexHash(const T* Object)
    {
        return reinterpret_cast<IndexHash>(Object);
    }
 
    template<typename T>
    IndexHash GenerateIndexHash(const TWeakObjectPtr<T>& Object)
    {
        return GenerateIndexHash(Object.Get());
    }
 
    template<typename T>
    IndexHash GenerateIndexHash(const TObjectPtr<T>& Object)
    {
        return GenerateIndexHash(Object.Get());
    }
    
    template<typename T>
    IndexHash GenerateIndexHash(const TStrongObjectPtr<T>& Object)
    {
        return GenerateIndexHash(Object.Get());
    }
 
    IndexHash GenerateIndexHash(const FString& Object)
    {
        return CityHash64(reinterpret_cast<const char*>(*Object), Object.Len() * sizeof(**Object));
    }
 
    IndexHash GenerateIndexHash(FStringView Object)
    {
        return CityHash64(reinterpret_cast<const char*>(Object.GetData()), Object.Len() * sizeof(*Object.GetData()));
    }
 
    IndexHash GenerateIndexHash(FName Object)
    {
        constexpr static const char SeedName[] = "FName";
        static uint64 Seed = CityHash64(SeedName, sizeof(SeedName) - 1);
        return CityHash128to64({ Seed, Object.ToUnstableInt() });
    }
 
    IndexHash GenerateIndexHash(const FSoftObjectPath& ObjectPath)
    {
        constexpr static const char SeedName[] = "FSoftObjectPath";
        static uint64 Seed = CityHash64(SeedName, sizeof(SeedName) - 1);
 
        FTopLevelAssetPath TopLevelAssetPath = ObjectPath.GetAssetPath();
        uint64 Hash = CityHash128to64({ Seed, GenerateIndexHash(TopLevelAssetPath.GetPackageName()) });
        Hash = CityHash128to64({ Hash, GenerateIndexHash(TopLevelAssetPath.GetAssetName()) });
        return CityHash128to64({ Hash, GenerateIndexHash(ObjectPath.GetSubPathString()) });
    }
} // namespace UE::Editor::DataStorage