Files
UnrealEngineUWP/Engine/Source/Developer/DerivedDataCache/Public/DerivedDataCacheKey.h
Devin Doucette a077feffbd DDC: Reworked ICacheStore to allow partial records, filtering of payloads, and loading parts of payloads
- ICacheStore::Put() has updated documentation to reflect the requirements of partial records.
- ICacheStore::Get() now takes a FCacheRecordPolicy, which is implicitly constructible from ECachePolicy, and allows setting the policy by payload.
- ICacheStore::GetPayload() is replaced by ICacheStore::GetChunks(), which allows loading parts of payloads.
- ICacheStore::CancelAll() is moved to ICache::CancelAll() because the cache can track requests at the top level and cancel them without exposing cancellation on individual cache stores.
- ECachePolicy::SkipLocalCopy has been removed because it is difficult to reason about.
- ECachePolicy::SkipData flags now have a documented meaning for put requests, to hint that record existence implies payload existence.
- The filesystem and memory cache stores have been updated to support partial records, filtering of payloads, and loading parts of payloads.
- Requesting part of a payload will decompress the entire payload for now, until compressed buffers expose a way to decompress only part.
- Fixed a bug in FTexturePlatformData::AreDerivedMipsAvailable() that caused it to return false for structured cache keys.

#rb Zousar.Shaker
#rnx
#preflight 615e03241ed62f0001b95454

#ROBOMERGE-OWNER: Devin.Doucette
#ROBOMERGE-AUTHOR: devin.doucette
#ROBOMERGE-SOURCE: CL 17748550 in //UE5/Release-5.0/... via CL 17748555
#ROBOMERGE-BOT: STARSHIP (Release-Engine-Staging -> Release-Engine-Test) (v879-17706426)
#ROBOMERGE-CONFLICT from-shelf
#ROBOMERGE[STARSHIP]: UE5-Main

[CL 17748602 by Devin Doucette in ue5-release-engine-test branch]
2021-10-07 09:11:32 -04:00

126 lines
3.6 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
#include "CoreTypes.h"
#include "Containers/StringFwd.h"
#include "Containers/StringView.h"
#include "IO/IoHash.h"
#include "Templates/TypeHash.h"
#define UE_API DERIVEDDATACACHE_API
namespace UE::DerivedData
{
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* An alphanumeric identifier that groups related cache records.
*
* A cache bucket name must be alphanumeric, non-empty, and contain fewer than 256 code units.
*/
class FCacheBucket
{
public:
/** Construct a null cache bucket. */
FCacheBucket() = default;
/** Create a cache bucket from a name. */
UE_API explicit FCacheBucket(FUtf8StringView Name);
UE_API explicit FCacheBucket(FWideStringView Name);
/** Whether this is null. */
inline bool IsNull() const { return !Name; }
/** Whether this is not null. */
inline bool IsValid() const { return !IsNull(); }
/** Reset this to null. */
inline void Reset() { *this = FCacheBucket(); }
inline bool operator==(FCacheBucket Other) const { return Name == Other.Name; }
inline bool operator!=(FCacheBucket Other) const { return Name != Other.Name; }
inline bool operator<(FCacheBucket Other) const
{
return Name != Other.Name && ToString().Compare(Other.ToString(), ESearchCase::IgnoreCase) < 0;
}
friend inline uint32 GetTypeHash(FCacheBucket Bucket)
{
return ::GetTypeHash(reinterpret_cast<UPTRINT>(Bucket.Name));
}
/** Get the name of the cache bucket as a string. */
inline FAnsiStringView ToString() const;
protected:
static constexpr int32 LengthOffset = -1;
/** Name stored as a null-terminated string preceded by one byte containing its length. */
const ANSICHAR* Name = nullptr;
};
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/** A key that uniquely identifies a cache record. */
struct FCacheKey
{
FCacheBucket Bucket;
FIoHash Hash;
/** A key with a null bucket and a zero hash. */
static const FCacheKey Empty;
};
inline const FCacheKey FCacheKey::Empty;
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
inline FAnsiStringView FCacheBucket::ToString() const
{
return Name ? FAnsiStringView(Name, reinterpret_cast<const uint8*>(Name)[LengthOffset]) : FAnsiStringView();
}
template <typename CharType>
inline TStringBuilderBase<CharType>& operator<<(TStringBuilderBase<CharType>& Builder, const FCacheBucket& Bucket)
{
return Builder << Bucket.ToString();
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
inline bool operator==(const FCacheKey& A, const FCacheKey& B)
{
return A.Bucket == B.Bucket && A.Hash == B.Hash;
}
inline bool operator!=(const FCacheKey& A, const FCacheKey& B)
{
return A.Bucket != B.Bucket || A.Hash != B.Hash;
}
inline bool operator<(const FCacheKey& A, const FCacheKey& B)
{
const FCacheBucket& BucketA = A.Bucket;
const FCacheBucket& BucketB = B.Bucket;
return BucketA == BucketB ? A.Hash < B.Hash : BucketA < BucketB;
}
inline uint32 GetTypeHash(const FCacheKey& Key)
{
return HashCombine(GetTypeHash(Key.Bucket), GetTypeHash(Key.Hash));
}
template <typename CharType>
inline TStringBuilderBase<CharType>& operator<<(TStringBuilderBase<CharType>& Builder, const FCacheKey& Key)
{
return Builder << Key.Bucket << CharType('/') << Key.Hash;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
} // UE::DerivedData
#undef UE_API