ObjectKey.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "Templates/Requires.h"
#include "UObject/WeakObjectPtr.h"
 
#include <type_traits>
 
struct FObjectKey;
 
namespace UE::CoreUObject::Private
{
    FObjectKey MakeObjectKey(int32 ObjectIndex, int32 ObjectSerialNumber);
}
 
struct FObjectKey
{
public:
    inline FObjectKey()
        : ObjectIndex(UE::Core::Private::InvalidWeakObjectIndex)
        , ObjectSerialNumber(0)
    {
    }
 
    inline FObjectKey(const UObject* Object)
        : ObjectIndex(UE::Core::Private::InvalidWeakObjectIndex)
        , ObjectSerialNumber(0)
    {
        if (Object)
        {
            FWeakObjectPtr Weak(Object);
            ObjectIndex = Weak.ObjectIndex;
            ObjectSerialNumber = Weak.ObjectSerialNumber;
#if UE_WITH_REMOTE_OBJECT_HANDLE
            RemoteId = Weak.ObjectRemoteId;
#endif
        }
    }
    template <
        typename U
        UE_REQUIRES(std::is_convertible_v<U, const UObject*>)
    >
    UE_FORCEINLINE_HINT FObjectKey(U Object)
        : FObjectKey(ImplicitConv<const UObject*>(Object))
    {
    }
 
    inline bool operator==(const FObjectKey& Other) const
    {
#if UE_WITH_REMOTE_OBJECT_HANDLE
        return RemoteId == Other.RemoteId;
#else
        return ObjectIndex == Other.ObjectIndex && ObjectSerialNumber == Other.ObjectSerialNumber;
#endif
    }
 
    inline bool operator!=(const FObjectKey& Other) const
    {
#if UE_WITH_REMOTE_OBJECT_HANDLE
        return RemoteId != Other.RemoteId;
#else
        return ObjectIndex != Other.ObjectIndex || ObjectSerialNumber != Other.ObjectSerialNumber;
#endif
    }
 
    inline bool operator<(const FObjectKey& Other) const
    {
#if UE_WITH_REMOTE_OBJECT_HANDLE
        return RemoteId < Other.RemoteId;
#else
        return ObjectIndex < Other.ObjectIndex || (ObjectIndex == Other.ObjectIndex && ObjectSerialNumber < Other.ObjectSerialNumber);
#endif
    }
 
    inline bool operator<=(const FObjectKey& Other) const
    {
#if UE_WITH_REMOTE_OBJECT_HANDLE
        return RemoteId <= Other.RemoteId;
#else
        return ObjectIndex <= Other.ObjectIndex || (ObjectIndex == Other.ObjectIndex && ObjectSerialNumber <= Other.ObjectSerialNumber);
#endif
    }
 
    inline bool operator>(const FObjectKey& Other) const
    {
#if UE_WITH_REMOTE_OBJECT_HANDLE
        return RemoteId > Other.RemoteId;
#else
        return ObjectIndex > Other.ObjectIndex || (ObjectIndex == Other.ObjectIndex && ObjectSerialNumber > Other.ObjectSerialNumber);
#endif
    }
 
    inline bool operator>=(const FObjectKey& Other) const
    {
#if UE_WITH_REMOTE_OBJECT_HANDLE
        return RemoteId >= Other.RemoteId;
#else
        return ObjectIndex > Other.ObjectIndex || (ObjectIndex == Other.ObjectIndex && ObjectSerialNumber >= Other.ObjectSerialNumber);
#endif
    }
 
    inline friend FArchive& operator<<(FArchive& Ar, FObjectKey& Key)
    {
        check(!Ar.IsPersistent());
        return Ar << Key.ObjectIndex << Key.ObjectSerialNumber
#if UE_WITH_REMOTE_OBJECT_HANDLE
            << Key.RemoteId
#endif
            ;
    }
 
    UObject* ResolveObjectPtr() const
    {
        FWeakObjectPtr WeakPtr;
        WeakPtr.ObjectIndex = ObjectIndex;
        WeakPtr.ObjectSerialNumber = ObjectSerialNumber;
#if UE_WITH_REMOTE_OBJECT_HANDLE
        WeakPtr.ObjectRemoteId = RemoteId;
#endif
        return WeakPtr.Get();
    }
 
    UObject* ResolveObjectPtrEvenIfGarbage() const
    {
        FWeakObjectPtr WeakPtr;
        WeakPtr.ObjectIndex = ObjectIndex;
        WeakPtr.ObjectSerialNumber = ObjectSerialNumber;
#if UE_WITH_REMOTE_OBJECT_HANDLE
        WeakPtr.ObjectRemoteId = RemoteId;
#endif
        constexpr bool bEvenIfGarbage = true;
        return WeakPtr.Get(bEvenIfGarbage);
    }
 
    UE_DEPRECATED(5.4, "Use ResolveObjectPtrEvenIfGarbage().")
    UObject* ResolveObjectPtrEvenIfPendingKill() const
    {
        return ResolveObjectPtrEvenIfGarbage();
    }
 
    UObject* ResolveObjectPtrEvenIfUnreachable() const
    {
        FWeakObjectPtr WeakPtr;
        WeakPtr.ObjectIndex = ObjectIndex;
        WeakPtr.ObjectSerialNumber = ObjectSerialNumber;
#if UE_WITH_REMOTE_OBJECT_HANDLE
        WeakPtr.ObjectRemoteId = RemoteId;
#endif
        return WeakPtr.GetEvenIfUnreachable();
    }
 
    FWeakObjectPtr GetWeakObjectPtr() const
    {
        FWeakObjectPtr WeakPtr;
        WeakPtr.ObjectIndex = ObjectIndex;
        WeakPtr.ObjectSerialNumber = ObjectSerialNumber;
#if UE_WITH_REMOTE_OBJECT_HANDLE
        WeakPtr.ObjectRemoteId = RemoteId;
#endif
        return WeakPtr;
    }
 
    [[nodiscard]] friend uint32 GetTypeHash(const FObjectKey& Key)
    {
#if UE_WITH_REMOTE_OBJECT_HANDLE
        return GetTypeHash(Key.RemoteId);
#else
        return HashCombine(Key.ObjectIndex, Key.ObjectSerialNumber);
#endif
    }
 
#if UE_WITH_REMOTE_OBJECT_HANDLE
    FRemoteObjectId GetRemoteId() const
    {
        return RemoteId;
    }
#endif
 
private:
#if !UE_WITH_REMOTE_OBJECT_HANDLE
    FObjectKey(int32 Index, int32 Serial)
        : ObjectIndex(Index)
        , ObjectSerialNumber(Serial)
    {
    }
 
    friend FObjectKey UE::CoreUObject::Private::MakeObjectKey(int32 ObjectIndex, int32 ObjectSerialNumber);
#endif
 
    int32       ObjectIndex;
    int32       ObjectSerialNumber;
#if UE_WITH_REMOTE_OBJECT_HANDLE
    FRemoteObjectId RemoteId;
#endif // UE_WITH_REMOTE_OBJECT_HANDLE
};
 
template<typename InElementType>
class TObjectKey
{
public:
    typedef InElementType ElementType;
 
    UE_FORCEINLINE_HINT TObjectKey() = default;
 
    template <
        typename U
        UE_REQUIRES(std::is_convertible_v<U, const InElementType*>)
    >
    UE_FORCEINLINE_HINT TObjectKey(U Object)
        : ObjectKey(ImplicitConv<const InElementType*>(Object))
    {
    }
 
    UE_FORCEINLINE_HINT bool operator==(const TObjectKey& Other) const
    {
        return ObjectKey == Other.ObjectKey;
    }
 
    UE_FORCEINLINE_HINT bool operator!=(const TObjectKey& Other) const
    {
        return ObjectKey != Other.ObjectKey;
    }
 
    UE_FORCEINLINE_HINT bool operator<(const TObjectKey& Other) const
    {
        return ObjectKey < Other.ObjectKey;
    }
 
    UE_FORCEINLINE_HINT bool operator<=(const TObjectKey& Other) const
    {
        return ObjectKey <= Other.ObjectKey;
    }
 
    UE_FORCEINLINE_HINT bool operator>(const TObjectKey& Other) const
    {
        return ObjectKey > Other.ObjectKey;
    }
 
    UE_FORCEINLINE_HINT bool operator>=(const TObjectKey& Other) const
    {
        return ObjectKey >= Other.ObjectKey;
    }
 
    //** Hash function */
    [[nodiscard]] friend uint32 GetTypeHash(const TObjectKey& Key)
    {
        return GetTypeHash(Key.ObjectKey);
    }
 
    InElementType* ResolveObjectPtr() const
    {
        return (InElementType*)ObjectKey.ResolveObjectPtr();
    }
 
    InElementType* ResolveObjectPtrEvenIfGarbage() const
    {
        return static_cast<InElementType*>(ObjectKey.ResolveObjectPtrEvenIfGarbage());
    }
 
    UE_DEPRECATED(5.4, "Use ResolveObjectPtrEvenIfGarbage().")
    InElementType* ResolveObjectPtrEvenIfPendingKill() const
    {
        return static_cast<InElementType*>(ObjectKey.ResolveObjectPtrEvenIfGarbage());
    }
 
private:
    FObjectKey ObjectKey;
};