IoChunkId.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreTypes.h"
#include "Containers/StringFwd.h"
#include "Memory/MemoryView.h"
#include "Misc/ByteSwap.h"
#include "String/BytesToHex.h"
 
class FArchive;
class FCbFieldView;
class FCbWriter;
class FPackageId;
class FIoContainerId;
 
enum class EIoChunkType : uint8
{
    Invalid = 0,
    ExportBundleData = 1,
    BulkData = 2,
    OptionalBulkData = 3,
    MemoryMappedBulkData = 4,
    ScriptObjects = 5,
    ContainerHeader = 6,
    ExternalFile = 7,
    ShaderCodeLibrary = 8,
    ShaderCode = 9,
    PackageStoreEntry = 10,
    DerivedData = 11,
    EditorDerivedData = 12,
    PackageResource = 13,
    MAX
};
 
CORE_API FString LexToString(const EIoChunkType Type);
 
inline bool IsBulkDataType(const EIoChunkType Type)
{
    if (Type == EIoChunkType::BulkData || Type == EIoChunkType::OptionalBulkData || Type == EIoChunkType::MemoryMappedBulkData)
    {
        return true;
    }
    else
    {
        return false;
    }
}
 
class FIoChunkId
{
public:
    CORE_API static const FIoChunkId InvalidChunkId;
 
    friend uint32 GetTypeHash(FIoChunkId InId)
    {
        uint32 Hash = 5381;
        for (int i = 0; i < sizeof Id; ++i)
        {
            Hash = Hash * 33 + InId.Id[i];
        }
        return Hash;
    }
 
    friend CORE_API FArchive& operator<<(FArchive& Ar, FIoChunkId& ChunkId);
    friend CORE_API FCbWriter& operator<<(FCbWriter& Writer, const FIoChunkId& ChunkId);
    friend CORE_API bool LoadFromCompactBinary(FCbFieldView Field, FIoChunkId& OutChunkId);
 
    template <typename CharType>
    friend TStringBuilderBase<CharType>& operator<<(TStringBuilderBase<CharType>& Builder, const FIoChunkId& ChunkId)
    {
        UE::String::BytesToHexLower(ChunkId.Id, Builder);
        return Builder;
    }
 
    CORE_API void ToString(FString& Output) const;
    friend CORE_API FString LexToString(const FIoChunkId& Id);
 
    inline bool operator ==(const FIoChunkId& Rhs) const
    {
        return 0 == FMemory::Memcmp(Id, Rhs.Id, sizeof Id);
    }
 
    inline bool operator !=(const FIoChunkId& Rhs) const
    {
        return !(*this == Rhs);
    }
 
    inline bool operator <(const FIoChunkId& Rhs) const
    {
        return FMemory::Memcmp(Id, Rhs.Id, sizeof Id) < 0;
    }
 
    inline bool operator >(const FIoChunkId& Rhs) const
    {
        return FMemory::Memcmp(Id, Rhs.Id, sizeof Id) > 0;
    }
 
    void Set(const void* InIdPtr, SIZE_T InSize)
    {
        check(InSize == sizeof Id);
        FMemory::Memcpy(Id, InIdPtr, sizeof Id);
    }
 
    void Set(FMemoryView InView)
    {
        check(InView.GetSize() == sizeof Id);
        FMemory::Memcpy(Id, InView.GetData(), sizeof Id);
    }
 
    inline bool IsValid() const
    {
        return *this != InvalidChunkId;
    }
 
    inline const uint8* GetData() const { return Id; }
    inline uint32       GetSize() const { return sizeof Id; }
 
    EIoChunkType GetChunkType() const
    {
        return static_cast<EIoChunkType>(Id[11]);
    }
 
    friend class FIoStoreReaderImpl;
 
    CORE_API static FIoChunkId FromHex(FStringView Hex);
 
private:
    static inline FIoChunkId CreateEmptyId()
    {
        FIoChunkId ChunkId;
        uint8 Data[12] = { 0 };
        ChunkId.Set(Data, sizeof Data);
 
        return ChunkId;
    }
 
    uint8   Id[12];
};
 
 
inline FIoChunkId CreateIoChunkId(uint64 ChunkId, uint16 ChunkIndex, EIoChunkType IoChunkType)
{
    checkSlow(IoChunkType != EIoChunkType::ExternalFile);   // Use CreateExternalFileChunkId() instead
    checkfSlow(IsBulkDataType(IoChunkType) == false, TEXT("Bulkdata types should call CreateBulkDataIoChunkId instead"));
 
    uint8 Data[12] = {0};
 
    *reinterpret_cast<uint64*>(&Data[0]) = ChunkId;
    *reinterpret_cast<uint16*>(&Data[8]) = NETWORK_ORDER16(ChunkIndex);
    *reinterpret_cast<uint8*>(&Data[11]) = static_cast<uint8>(IoChunkType);
 
    FIoChunkId IoChunkId;
    IoChunkId.Set(Data, 12);
 
    return IoChunkId;
}
 
 
 
inline FIoChunkId CreateBulkDataIoChunkId(uint64 ChunkId, uint16 ChunkIndex, uint8 ChunkGroup, EIoChunkType IoChunkType)
{
    checkSlow(IoChunkType != EIoChunkType::ExternalFile);   // Use CreateExternalFileChunkId() instead
    checkfSlow(IsBulkDataType(IoChunkType), TEXT("CreateBulkDataIoChunkId is only intended for bulkdata types"));
    
    uint8 Data[12] = { 0 };
 
    *reinterpret_cast<uint64*>(&Data[0]) = ChunkId;
    *reinterpret_cast<uint16*>(&Data[8]) = NETWORK_ORDER16(ChunkIndex);
    *reinterpret_cast<uint8*>(&Data[10]) = ChunkGroup;
    *reinterpret_cast<uint8*>(&Data[11]) = static_cast<uint8>(IoChunkType);
 
    FIoChunkId IoChunkId;
    IoChunkId.Set(Data, 12);
 
    return IoChunkId;
}
 
CORE_API FIoChunkId CreatePackageDataChunkId(const FPackageId& PackageId);
 
CORE_API FIoChunkId CreateExternalFileChunkId(const FStringView Filename);
 
CORE_API FIoChunkId CreateContainerHeaderChunkId(const FIoContainerId& ContainerId);