UnrealEngineUWP/Engine/Source/Runtime/RuntimeAssetCache/Private/RuntimeAssetCacheBackend.cpp

// Copyright 1998-2015 Epic Games, Inc. All Rights Reserved.

#include "RuntimeAssetCachePrivatePCH.h"
#include "RuntimeAssetCacheBackend.h"
#include "RuntimeAssetCacheFilesystemBackend.h"
#include "RuntimeAssetCacheEntryMetadata.h"


FCacheEntryMetadata* FRuntimeAssetCacheBackend::GetCachedData(const FName Bucket, const TCHAR* CacheKey, TArray<uint8>& OutData)
{
	FCacheEntryMetadata* Result = nullptr;
	FArchive* Ar = CreateReadArchive(Bucket, CacheKey);
	if (!Ar)
	{
		return Result;
	}

	Result = PreloadMetadata(Ar);

	int64 TotalSize = Ar->TotalSize();
	int64 CurrentPosition = Ar->Tell();
	int64 NumberOfBytesToSerialize = TotalSize - CurrentPosition;
	OutData.Reset();
	OutData.AddUninitialized(NumberOfBytesToSerialize);

	Ar->Serialize(OutData.GetData(), NumberOfBytesToSerialize);
	Ar->Close();
	delete Ar;
	return Result;
}

bool FRuntimeAssetCacheBackend::PutCachedData(const FName Bucket, const TCHAR* CacheKey, TArray<uint8>& InData, FCacheEntryMetadata* Metadata)
{
	bool bResult = false;
	FArchive* Ar = CreateWriteArchive(Bucket, CacheKey);
	if (!Ar)
	{
		return bResult;
	}

	*Ar << *Metadata;
	Ar->Serialize(InData.GetData(), InData.Num());
	bResult = Ar->Close();
	delete Ar;
	return bResult;
}

FRuntimeAssetCacheBackend* FRuntimeAssetCacheBackend::CreateBackend()
{
	return new FRuntimeAssetCacheFilesystemBackend();
}

FCacheEntryMetadata* FRuntimeAssetCacheBackend::PreloadMetadata(FArchive* Ar)
{
	FCacheEntryMetadata* Result = new FCacheEntryMetadata();
	*Ar << *Result;
	return Result;
}