path: root/src/zenremotestore/chunking/chunkingcache.cpp

// Copyright Epic Games, Inc. All Rights Reserved.

#include <zenremotestore/chunking/chunkingcache.h>

#include <zenbase/zenbase.h>
#include <zencore/basicfile.h>
#include <zencore/compactbinarybuilder.h>
#include <zencore/compactbinaryutil.h>
#include <zencore/filesystem.h>
#include <zencore/fmtutils.h>
#include <zencore/logging.h>
#include <zenremotestore/chunking/chunkedfile.h>
#include <zenremotestore/chunking/chunkingcontroller.h>

ZEN_THIRD_PARTY_INCLUDES_START
#include <tsl/robin_map.h>
#include <xxhash.h>
#include <gsl/gsl-lite.hpp>
ZEN_THIRD_PARTY_INCLUDES_END

#if ZEN_WITH_TESTS
#	include <zencore/testing.h>
#	include <zencore/testutils.h>
#	include <algorithm>
#endif	// ZEN_WITH_TESTS

namespace zen {

class NullChunkingCache : public ChunkingCache
{
public:
	NullChunkingCache() {}

	virtual bool GetCachedFile(const std::filesystem::path& InputPath,
							   uint64_t						RawSize,
							   uint64_t						ModificationTick,
							   ChunkedInfoWithSource&		OutChunked) override
	{
		ZEN_UNUSED(InputPath, RawSize, OutChunked, ModificationTick);
		return false;
	}

	virtual bool PutCachedFile(const std::filesystem::path& InputPath,
							   uint64_t						ModificationTick,
							   const ChunkedInfoWithSource& Chunked) override
	{
		ZEN_UNUSED(InputPath, Chunked, ModificationTick);
		return false;
	}
};

class MemoryChunkingCache : public ChunkingCache
{
public:
	MemoryChunkingCache() {}

	virtual bool GetCachedFile(const std::filesystem::path& InputPath,
							   uint64_t						RawSize,
							   uint64_t						ModificationTick,
							   ChunkedInfoWithSource&		OutChunked) override
	{
		const std::u8string PathString = InputPath.generic_u8string();
		const IoHash		PathHash   = IoHash::HashBuffer(PathString.data(), PathString.length());

		RwLock::SharedLockScope Lock(m_Lock);
		if (auto It = m_PathHashToEntry.find(PathHash); It != m_PathHashToEntry.end())
		{
			const CachedEntry& Entry = m_Entries[It->second];
			if (ModificationTick == Entry.ModificationTick && RawSize == Entry.Chunked.Info.RawSize)
			{
				OutChunked = Entry.Chunked;
				return true;
			}
			else
			{
				Lock.ReleaseNow();
				RwLock::ExclusiveLockScope EditLock(m_Lock);
				if (auto RemoveIt = m_PathHashToEntry.find(PathHash); It != m_PathHashToEntry.end())
				{
					CachedEntry& DeleteEntry	 = m_Entries[It->second];
					DeleteEntry.Chunked			 = {};
					DeleteEntry.ModificationTick = 0;
					m_FreeEntryIndexes.push_back(It->second);
					m_PathHashToEntry.erase(It);
				}
			}
		}
		return false;
	}

	virtual bool PutCachedFile(const std::filesystem::path& InputPath,
							   uint64_t						ModificationTick,
							   const ChunkedInfoWithSource& Chunked) override
	{
		const std::u8string PathString = InputPath.generic_u8string();
		const IoHash		PathHash   = IoHash::HashBuffer(PathString.data(), PathString.length());

		RwLock::ExclusiveLockScope _(m_Lock);
		if (auto It = m_PathHashToEntry.find(PathHash); It != m_PathHashToEntry.end())
		{
			CachedEntry& Entry = m_Entries[It->second];
			if (ModificationTick != Entry.ModificationTick || Chunked.Info.RawSize != Entry.Chunked.Info.RawSize)
			{
				Entry.Chunked		   = Chunked;
				Entry.ModificationTick = ModificationTick;
			}
		}
		else
		{
			uint32_t EntryIndex = gsl::narrow<uint32_t>(m_Entries.size());
			if (!m_FreeEntryIndexes.empty())
			{
				EntryIndex = m_FreeEntryIndexes.back();
				m_FreeEntryIndexes.pop_back();
				m_Entries[EntryIndex] = CachedEntry{.Chunked = Chunked, .ModificationTick = ModificationTick};
			}
			else
			{
				m_Entries.emplace_back(CachedEntry{.Chunked = Chunked, .ModificationTick = ModificationTick});
			}
			m_PathHashToEntry.insert_or_assign(PathHash, EntryIndex);
		}
		return true;
	}

	RwLock m_Lock;

	tsl::robin_map<IoHash, uint32_t, IoHash::Hasher> m_PathHashToEntry;
	std::vector<uint32_t>							 m_FreeEntryIndexes;

	struct CachedEntry
	{
		ChunkedInfoWithSource Chunked;
		uint64_t			  ModificationTick = 0;
	};

	std::vector<CachedEntry> m_Entries;
};

class DiskChunkingCache : public ChunkingCache
{
public:
	DiskChunkingCache(const std::filesystem::path& RootPath, ChunkingController& ChunkController, uint64_t MinimumRawSizeForCaching)
	: m_RootPath(RootPath)
	, m_ChunkerId(GetChunkerIdentity(ChunkController))
	, m_MinimumRawSizeForCaching(MinimumRawSizeForCaching)
	{
	}

	virtual bool GetCachedFile(const std::filesystem::path& InputPath,
							   uint64_t						RawSize,
							   uint64_t						ModificationTick,
							   ChunkedInfoWithSource&		OutChunked) override
	{
		if (RawSize < m_MinimumRawSizeForCaching)
		{
			return false;
		}

		const std::filesystem::path CachePath = GetCachePath(InputPath);

		return ReadChunkedInfo(CachePath, RawSize, ModificationTick, OutChunked);
	}

	virtual bool PutCachedFile(const std::filesystem::path& InputPath,
							   uint64_t						ModificationTick,
							   const ChunkedInfoWithSource& Chunked) override
	{
		if (Chunked.Info.RawSize < m_MinimumRawSizeForCaching)
		{
			return false;
		}

		const std::filesystem::path CachePath = GetCachePath(InputPath);

		return WriteChunkedInfo(CachePath, ModificationTick, Chunked);
	}

private:
	static constexpr uint32_t ImplementationRevision = 1;

#pragma pack(push)
#pragma pack(1)
	struct ChunkedInfoHeader
	{
		static constexpr uint32_t ExpectedMagic	 = 0x75636368;	// 'ucch';
		static constexpr uint32_t CurrentVersion = 1;

		uint32_t Magic			  = ExpectedMagic;
		uint32_t Version		  = CurrentVersion;
		uint64_t SequenceCount	  = 0;
		uint64_t ChunkCount		  = 0;
		uint64_t RawSize		  = 0;
		IoHash	 RawHash		  = IoHash::Zero;
		uint64_t ModificationTick = 0;
		uint32_t Checksum		  = 0;

		static uint32_t ComputeChecksum(const ChunkedInfoHeader& Header)
		{
			return XXH32(&Header.Magic, sizeof(Header) - sizeof(uint32_t), 0xC0C0'BABA);
		}
	};
#pragma pack(pop)
	static_assert(sizeof(ChunkedInfoHeader) == 64);
	static_assert(sizeof(ChunkSource) == 12);

	std::filesystem::path GetCachePath(const std::filesystem::path& InputPath)
	{
		const std::string	  IdentityString = fmt::format("{}_{}_{}", ImplementationRevision, m_ChunkerId, InputPath.generic_string());
		const IoHash		  IdentityHash	 = IoHash::HashBuffer(IdentityString.data(), IdentityString.length());
		std::filesystem::path CachePath		 = m_RootPath / fmt::format("{}.chunked_content", IdentityHash);
		return CachePath;
	}

	bool WriteChunkedInfo(const std::filesystem::path& CachePath, uint64_t ModificationTick, const ChunkedInfoWithSource& Chunked)
	{
		CreateDirectories(CachePath.parent_path());

		TemporaryFile	OutputFile;
		std::error_code Ec;
		OutputFile.CreateTemporary(CachePath.parent_path(), Ec);
		if (Ec)
		{
			ZEN_DEBUG("Failed to create temp file for cached chunked data at '{}'", CachePath);
			return false;
		}
		ChunkedInfoHeader Header = {.SequenceCount	  = Chunked.Info.ChunkSequence.size(),
									.ChunkCount		  = Chunked.Info.ChunkHashes.size(),
									.RawSize		  = Chunked.Info.RawSize,
									.RawHash		  = Chunked.Info.RawHash,
									.ModificationTick = ModificationTick};

		Header.Checksum = ChunkedInfoHeader::ComputeChecksum(Header);

		try
		{
			uint64_t Offset = 0;

			OutputFile.Write(&Header, sizeof(ChunkedInfoHeader), Offset);
			Offset += sizeof(ChunkedInfoHeader);

			if (Header.SequenceCount > 0)
			{
				OutputFile.Write(Chunked.Info.ChunkSequence.data(), Header.SequenceCount * sizeof(uint32_t), Offset);
				Offset += Header.SequenceCount * sizeof(uint32_t);
			}

			if (Header.ChunkCount > 0)
			{
				OutputFile.Write(Chunked.Info.ChunkHashes.data(), Header.ChunkCount * sizeof(IoHash), Offset);
				Offset += Header.ChunkCount * sizeof(IoHash);

				OutputFile.Write(Chunked.ChunkSources.data(), Header.ChunkCount * sizeof(ChunkSource), Offset);
				Offset += Header.ChunkCount * sizeof(ChunkSource);
			}

			OutputFile.Flush();
		}
		catch (const std::exception& Ex)
		{
			ZEN_DEBUG("Failed to write cached file {}. Reason: {}", CachePath, Ex.what());
			return false;
		}
		OutputFile.MoveTemporaryIntoPlace(CachePath, Ec);
		if (Ec)
		{
			ZEN_DEBUG("Failed to move temporary file {} to {}. Reason: {}", OutputFile.GetPath(), CachePath, Ec.message());
			return false;
		}

		return true;
	}

	bool ReadChunkedInfo(const std::filesystem::path& CachePath,
						 uint64_t					  RawSize,
						 uint64_t					  ModificationTick,
						 ChunkedInfoWithSource&		  OutChunked)
	{
		BasicFile		InputFile;
		std::error_code Ec;
		InputFile.Open(CachePath, BasicFile::Mode::kRead, Ec);
		if (Ec)
		{
			return false;
		}
		try
		{
			uint64_t Size = InputFile.FileSize();
			if (Size < sizeof(ChunkedInfoHeader))
			{
				throw std::runtime_error(fmt::format("Expected size >= {}, file has size {}", sizeof(ChunkedInfoHeader), Size));
			}

			uint64_t		  Offset = 0;
			ChunkedInfoHeader Header;
			InputFile.Read(&Header, sizeof(ChunkedInfoHeader), Offset);
			Offset += sizeof(Header);

			if (Header.Magic != ChunkedInfoHeader::ExpectedMagic)
			{
				throw std::runtime_error(
					fmt::format("Expected magic 0x{:04x}, file has magic 0x{:04x}", ChunkedInfoHeader::ExpectedMagic, Header.Magic));
			}
			if (Header.Version != ChunkedInfoHeader::CurrentVersion)
			{
				throw std::runtime_error(
					fmt::format("Expected version {}, file has version {}", ChunkedInfoHeader::CurrentVersion, Header.Version));
			}
			if (Header.Checksum != ChunkedInfoHeader::ComputeChecksum(Header))
			{
				throw std::runtime_error(fmt::format("Expected checksum 0x{:04x}, file has checksum 0x{:04x}",
													 Header.Checksum,
													 ChunkedInfoHeader::ComputeChecksum(Header)));
			}

			uint64_t ExpectedSize = sizeof(ChunkedInfoHeader) + Header.SequenceCount * sizeof(uint32_t) +
									Header.ChunkCount * sizeof(IoHash) + Header.ChunkCount * sizeof(ChunkSource);

			if (ExpectedSize != Size)
			{
				throw std::runtime_error(fmt::format("Expected size {}, file has size {}", ExpectedSize, Size));
			}

			if (Header.RawSize != RawSize)
			{
				InputFile.Close();
				RemoveFile(CachePath, Ec);
				return false;
			}

			if (Header.ModificationTick != ModificationTick)
			{
				InputFile.Close();
				RemoveFile(CachePath, Ec);
				return false;
			}

			OutChunked.Info.RawSize = Header.RawSize;
			OutChunked.Info.RawHash = Header.RawHash;

			if (Header.SequenceCount > 0)
			{
				OutChunked.Info.ChunkSequence.resize(Header.SequenceCount);
				InputFile.Read(OutChunked.Info.ChunkSequence.data(), Header.SequenceCount * sizeof(uint32_t), Offset);
				Offset += Header.SequenceCount * sizeof(uint32_t);
			}

			if (Header.ChunkCount > 0)
			{
				OutChunked.Info.ChunkHashes.resize(Header.ChunkCount);
				OutChunked.ChunkSources.resize(Header.ChunkCount);

				InputFile.Read(OutChunked.Info.ChunkHashes.data(), Header.ChunkCount * sizeof(IoHash), Offset);
				Offset += Header.ChunkCount * sizeof(IoHash);

				InputFile.Read(OutChunked.ChunkSources.data(), Header.ChunkCount * sizeof(ChunkSource), Offset);
				Offset += Header.ChunkCount * sizeof(ChunkSource);
			}
		}
		catch (const std::exception& Ex)
		{
			ZEN_DEBUG("Failed to read cached file {}. Reason: {}", CachePath, Ex.what());
			InputFile.Close();
			RemoveFile(CachePath, Ec);
			return false;
		}

		return true;
	}

	const std::filesystem::path m_RootPath;
	const IoHash				m_ChunkerId;
	const uint64_t				m_MinimumRawSizeForCaching;

	static IoHash GetChunkerIdentity(ChunkingController& ChunkController)
	{
		IoHashStream	 ChunkerIdStream;
		std::string_view ChunkerName = ChunkController.GetName();
		ChunkerIdStream.Append(ChunkerName.data(), ChunkerName.length());
		const CbObject ChunkerParameters = ChunkController.GetParameters();
		ChunkerParameters.GetHash(ChunkerIdStream);
		return ChunkerIdStream.GetHash();
	}
};

std::unique_ptr<ChunkingCache>
CreateNullChunkingCache()
{
	return std::make_unique<NullChunkingCache>();
}

std::unique_ptr<ChunkingCache>
CreateMemoryChunkingCache()
{
	return std::make_unique<MemoryChunkingCache>();
}

std::unique_ptr<ChunkingCache>
CreateDiskChunkingCache(const std::filesystem::path& RootPath, ChunkingController& ChunkController, uint64_t MinimumRawSizeForCaching)
{
	return std::make_unique<DiskChunkingCache>(RootPath, ChunkController, MinimumRawSizeForCaching);
}

#if ZEN_WITH_TESTS

namespace chunkingcache_testutils {
	ChunkedInfoWithSource CreateChunked(const std::string_view Data, uint32_t SplitSize)
	{
		std::vector<uint32_t>	 ChunkSequence;
		std::vector<IoHash>		 ChunkHashes;
		std::vector<ChunkSource> ChunkSources;

		if (SplitSize > 0)
		{
			std::string_view::size_type SplitOffset = 0;
			while (SplitOffset < Data.length())
			{
				std::string_view DataPart(Data.substr(SplitOffset, SplitSize));

				ChunkSequence.push_back(gsl::narrow<uint32_t>(ChunkSequence.size()));
				ChunkHashes.push_back(IoHash::HashBuffer(DataPart.data(), DataPart.length()));
				ChunkSources.push_back({.Offset = SplitOffset, .Size = gsl::narrow<uint32_t>(DataPart.length())});
				SplitOffset += DataPart.length();
			}
		}

		return ChunkedInfoWithSource{.Info		   = {.RawSize		 = Data.length(),
													  .RawHash		 = IoHash::HashBuffer(Data.data(), Data.length()),
													  .ChunkSequence = std::move(ChunkSequence),
													  .ChunkHashes	 = std::move(ChunkHashes)},
									 .ChunkSources = std::move(ChunkSources)};
	}

	bool Equals(const ChunkedInfoWithSource& Lhs, const ChunkedInfoWithSource& Rhs)
	{
		if (Lhs.ChunkSources.size() != Rhs.ChunkSources.size())
		{
			return false;
		}
		if (std::mismatch(Lhs.ChunkSources.begin(),
						  Lhs.ChunkSources.end(),
						  Rhs.ChunkSources.begin(),
						  [](const ChunkSource& Lhs, const ChunkSource& Rhs) { return Lhs.Offset == Rhs.Offset && Lhs.Size == Rhs.Size; })
				.first != Lhs.ChunkSources.end())
		{
			return false;
		}
		if (Lhs.Info.RawSize != Rhs.Info.RawSize)
		{
			return false;
		}
		if (Lhs.Info.ChunkSequence != Rhs.Info.ChunkSequence)
		{
			return false;
		}
		if (Lhs.Info.ChunkHashes != Rhs.Info.ChunkHashes)
		{
			return false;
		}
		return true;
	}
}  // namespace chunkingcache_testutils

TEST_CASE("chunkingcache.nullchunkingcache")
{
	using namespace chunkingcache_testutils;

	std::unique_ptr<ChunkingCache> Cache = CreateNullChunkingCache();
	ChunkedInfoWithSource		   Result;
	CHECK(!Cache->GetCachedFile("dummy-path", 495, 91283, Result));
	CHECK(Result.Info.ChunkHashes.empty());

	ChunkedInfoWithSource Chunked = CreateChunked("my data string", 4);
	CHECK(!Cache->PutCachedFile("dummy-path", 91283, Chunked));

	CHECK(!Cache->GetCachedFile("dummy-path", 495, 91283, Result));
	CHECK(Result.Info.ChunkHashes.empty());
}

TEST_CASE("chunkingcache.memorychunkingcache")
{
	using namespace chunkingcache_testutils;

	std::unique_ptr<ChunkingCache> Cache = CreateMemoryChunkingCache();
	ChunkedInfoWithSource		   Result;
	CHECK(!Cache->GetCachedFile("file/A/Path", 495, 91283, Result));
	CHECK(Result.Info.ChunkHashes.empty());
	CHECK(!Cache->GetCachedFile("file/B/Path", 395, 671283, Result));
	CHECK(Result.Info.ChunkHashes.empty());

	ChunkedInfoWithSource ChunkedAV1 = CreateChunked("File A data string", 4);
	ChunkedInfoWithSource ChunkedAV2 = CreateChunked("File A updated data string", 4);
	ChunkedInfoWithSource ChunkedBV1 = CreateChunked("File B data string", 4);

	CHECK(Cache->PutCachedFile("file/A/Path", 91283, ChunkedAV1));
	CHECK(Cache->PutCachedFile("file/B/Path", 51283, ChunkedBV1));

	CHECK(Cache->GetCachedFile("file/A/Path", ChunkedAV1.Info.RawSize, 91283, Result));
	CHECK(Equals(Result, ChunkedAV1));
	Result = ChunkedInfoWithSource{};

	CHECK(Cache->GetCachedFile("file/B/Path", ChunkedBV1.Info.RawSize, 51283, Result));
	CHECK(Equals(Result, ChunkedBV1));
	Result = ChunkedInfoWithSource{};

	CHECK(!Cache->GetCachedFile("file/A/Path-wrong", 495, 91283, Result));
	CHECK(Result.Info.ChunkHashes.empty());

	CHECK(!Cache->GetCachedFile("file/A/Path", 493, 91283, Result));
	CHECK(Result.Info.ChunkHashes.empty());

	// Asking a path that exists but without a match will remove that path
	CHECK(!Cache->GetCachedFile("file/A/Path", 495, 91283, Result));
	CHECK(Result.Info.ChunkHashes.empty());

	CHECK(!Cache->GetCachedFile("file/A/Path", 495, 9283, Result));
	CHECK(Result.Info.ChunkHashes.empty());

	CHECK(Cache->PutCachedFile("file/A/Path", 91283, ChunkedAV1));
	CHECK(Cache->GetCachedFile("file/A/Path", ChunkedAV1.Info.RawSize, 91283, Result));
	CHECK(Equals(Result, ChunkedAV1));
	Result = ChunkedInfoWithSource{};

	CHECK(Cache->PutCachedFile("file/A/Path", 91483, ChunkedAV2));
	CHECK(Cache->GetCachedFile("file/A/Path", ChunkedAV2.Info.RawSize, 91483, Result));
	CHECK(Equals(Result, ChunkedAV2));
	Result = ChunkedInfoWithSource{};

	CHECK(!Cache->GetCachedFile("file/A/Path", ChunkedAV1.Info.RawSize, 91283, Result));
	CHECK(Result.Info.ChunkHashes.empty());

	CHECK(Cache->GetCachedFile("file/B/Path", ChunkedBV1.Info.RawSize, 51283, Result));
	CHECK(Equals(Result, ChunkedBV1));
	Result = ChunkedInfoWithSource{};

	CHECK(!Cache->GetCachedFile("file/B/Path", ChunkedBV1.Info.RawSize + 1, 51283, Result));
	CHECK(Result.Info.ChunkHashes.empty());
}

TEST_CASE("chunkingcache.diskchunkingcache")
{
	using namespace chunkingcache_testutils;

	ScopedTemporaryDirectory TmpDir;

	std::unique_ptr<ChunkingController> ChunkController = CreateStandardChunkingController(StandardChunkingControllerSettings{});

	ChunkedInfoWithSource ChunkedAV1 = CreateChunked("File A data string", 4);
	ChunkedInfoWithSource ChunkedAV2 = CreateChunked("File A updated data string", 4);
	ChunkedInfoWithSource ChunkedBV1 = CreateChunked("File B data string", 4);

	{
		std::unique_ptr<ChunkingCache> Cache = CreateDiskChunkingCache(TmpDir.Path(), *ChunkController, 0);
		ChunkedInfoWithSource		   Result;
		CHECK(!Cache->GetCachedFile("file/A/Path", 495, 91283, Result));
		CHECK(Result.Info.ChunkHashes.empty());
		CHECK(!Cache->GetCachedFile("file/B/Path", 395, 671283, Result));
		CHECK(Result.Info.ChunkHashes.empty());

		CHECK(Cache->PutCachedFile("file/A/Path", 91283, ChunkedAV1));
		CHECK(Cache->PutCachedFile("file/B/Path", 51283, ChunkedBV1));

		CHECK(Cache->GetCachedFile("file/A/Path", ChunkedAV1.Info.RawSize, 91283, Result));
		CHECK(Equals(Result, ChunkedAV1));
		Result = ChunkedInfoWithSource{};

		CHECK(Cache->GetCachedFile("file/B/Path", ChunkedBV1.Info.RawSize, 51283, Result));
		CHECK(Equals(Result, ChunkedBV1));
		Result = ChunkedInfoWithSource{};

		CHECK(!Cache->GetCachedFile("file/A/Path-wrong", 495, 91283, Result));
		CHECK(Result.Info.ChunkHashes.empty());

		CHECK(!Cache->GetCachedFile("file/A/Path", 493, 91283, Result));
		CHECK(Result.Info.ChunkHashes.empty());

		// Asking a path that exists but without a match will remove that path
		CHECK(!Cache->GetCachedFile("file/A/Path", 495, 91283, Result));
		CHECK(Result.Info.ChunkHashes.empty());

		CHECK(!Cache->GetCachedFile("file/A/Path", 495, 9283, Result));
		CHECK(Result.Info.ChunkHashes.empty());

		CHECK(Cache->PutCachedFile("file/A/Path", 91283, ChunkedAV1));
		CHECK(Cache->GetCachedFile("file/A/Path", ChunkedAV1.Info.RawSize, 91283, Result));
		CHECK(Equals(Result, ChunkedAV1));
		Result = ChunkedInfoWithSource{};

		CHECK(Cache->PutCachedFile("file/A/Path", 91483, ChunkedAV2));
		CHECK(Cache->GetCachedFile("file/A/Path", ChunkedAV2.Info.RawSize, 91483, Result));
		CHECK(Equals(Result, ChunkedAV2));
		Result = ChunkedInfoWithSource{};
	}
	{
		std::unique_ptr<ChunkingCache> Cache = CreateDiskChunkingCache(TmpDir.Path(), *ChunkController, 0);
		ChunkedInfoWithSource		   Result;

		CHECK(Cache->GetCachedFile("file/A/Path", ChunkedAV2.Info.RawSize, 91483, Result));
		CHECK(Equals(Result, ChunkedAV2));
		Result = ChunkedInfoWithSource{};

		CHECK(!Cache->GetCachedFile("file/A/Path", ChunkedAV2.Info.RawSize, 91283, Result));
		CHECK(Result.Info.ChunkHashes.empty());

		CHECK(!Cache->GetCachedFile("file/A/Path", ChunkedAV2.Info.RawSize, 91483, Result));
		CHECK(Result.Info.ChunkHashes.empty());

		CHECK(Cache->GetCachedFile("file/B/Path", ChunkedBV1.Info.RawSize, 51283, Result));
		CHECK(Equals(Result, ChunkedBV1));
		Result = ChunkedInfoWithSource{};

		CHECK(!Cache->GetCachedFile("file/B/Path", ChunkedBV1.Info.RawSize + 1, 51283, Result));
		CHECK(Result.Info.ChunkHashes.empty());

		CHECK(!Cache->GetCachedFile("file/B/Path", ChunkedBV1.Info.RawSize, 51283, Result));
		CHECK(Result.Info.ChunkHashes.empty());
	}
}

void
chunkingcache_forcelink()
{
}

#endif	// ZEN_WITH_TESTS

}  // namespace zen