StaticMemoryReader.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreTypes.h"
#include "HAL/UnrealMemory.h"
#include "Math/UnrealMathUtility.h"
#include "Containers/UnrealString.h"
#include "Serialization/MemoryArchive.h"
 
/**
 * Archive for reading arbitrary data from the specified memory location
 */
class FStaticMemoryReader final : public FMemoryArchive
{
public:
    /**
     * Returns the name of the Archive.  Useful for getting the name of the package a struct or object
     * is in when a loading error occurs.
     *
     * This is overridden for the specific Archive Types
     **/
    virtual FString GetArchiveName() const override
    {
        return TEXT("FStaticMemoryReader");
    }
 
    virtual int64 TotalSize() override
    {
        return NumBytes;
    }
 
    void Serialize( void* Data, int64 Num )
    {
        if (Num && !IsError())
        {
            // Only serialize if we have the requested amount of data
            if (Offset + Num <= TotalSize())
            {
                FMemory::Memcpy( Data, &Bytes[Offset], Num );
                Offset += Num;
            }
            else
            {
                SetError();
            }
        }
    }
 
    explicit FStaticMemoryReader(const uint8* InBytes, int64 InNumBytes)
        : Bytes   (InBytes)
        , NumBytes(InNumBytes)
    {
        this->SetIsLoading(true);
    }
 
private:
    const uint8* Bytes;
    int64        NumBytes;
};