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// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
#include "cachedisklayer.h"
#include "stats/statsreporter.h"
#include <zencore/compactbinary.h>
#include <zencore/iohash.h>
#include <zencore/stats.h>
#include <zenstore/gc.h>
#include <zenutil/cache/cache.h>
#include <atomic>
#include <compare>
#include <filesystem>
#include <string_view>
#include <unordered_map>
namespace zen {
class StatsDaemonClient;
/******************************************************************************
/$$$$$$$$ /$$$$$$ /$$
|_____ $$ /$$__ $$ | $$
/$$/ /$$$$$$ /$$$$$$$ | $$ \__/ /$$$$$$ /$$$$$$| $$$$$$$ /$$$$$$
/$$/ /$$__ $| $$__ $$ | $$ |____ $$/$$_____| $$__ $$/$$__ $$
/$$/ | $$$$$$$| $$ \ $$ | $$ /$$$$$$| $$ | $$ \ $| $$$$$$$$
/$$/ | $$_____| $$ | $$ | $$ $$/$$__ $| $$ | $$ | $| $$_____/
/$$$$$$$| $$$$$$| $$ | $$ | $$$$$$| $$$$$$| $$$$$$| $$ | $| $$$$$$$
|________/\_______|__/ |__/ \______/ \_______/\_______|__/ |__/\_______/
Cache store for UE5. Restricts keys to "{bucket}/{hash}" pairs where the hash
is 40 (hex) chars in size. Values may be opaque blobs or structured objects
which can in turn contain references to other objects (or blobs). Buckets are
organized in namespaces to enable project isolation.
******************************************************************************/
class WorkerThreadPool;
class DiskWriteBlocker;
class JobQueue;
/* Z$ namespace
A namespace scopes a set of buckets, and would typically be used to isolate
projects from each other.
*/
class ZenCacheNamespace final : public GcStorage, public GcContributor
{
public:
struct Configuration
{
ZenCacheDiskLayer::Configuration DiskLayerConfig;
};
struct BucketInfo
{
ZenCacheDiskLayer::BucketInfo DiskLayerInfo;
};
struct Info
{
std::filesystem::path RootDir;
Configuration Config;
std::vector<std::string> BucketNames;
ZenCacheDiskLayer::Info DiskLayerInfo;
};
struct NamespaceStats
{
uint64_t HitCount;
uint64_t MissCount;
uint64_t WriteCount;
metrics::RequestStatsSnapshot PutOps;
metrics::RequestStatsSnapshot GetOps;
ZenCacheDiskLayer::DiskStats DiskStats;
};
ZenCacheNamespace(GcManager& Gc, JobQueue& JobQueue, const std::filesystem::path& RootDir, const Configuration& Config);
~ZenCacheNamespace();
bool Get(std::string_view Bucket, const IoHash& HashKey, ZenCacheValue& OutValue);
void Put(std::string_view Bucket, const IoHash& HashKey, const ZenCacheValue& Value, std::span<IoHash> References);
bool DropBucket(std::string_view Bucket);
void EnumerateBucketContents(std::string_view Bucket,
std::function<void(const IoHash& Key, const CacheValueDetails::ValueDetails& Details)>& Fn) const;
bool Drop();
void Flush();
// GcContributor
virtual void GatherReferences(GcContext& GcCtx) override;
// GcStorage
virtual void ScrubStorage(ScrubContext& ScrubCtx) override;
virtual void CollectGarbage(GcContext& GcCtx) override;
virtual GcStorageSize StorageSize() const override;
Configuration GetConfig() const { return m_Configuration; }
Info GetInfo() const;
std::optional<BucketInfo> GetBucketInfo(std::string_view Bucket) const;
NamespaceStats Stats();
CacheValueDetails::NamespaceDetails GetValueDetails(const std::string_view BucketFilter, const std::string_view ValueFilter) const;
#if ZEN_WITH_TESTS
void SetAccessTime(std::string_view Bucket, const IoHash& HashKey, GcClock::TimePoint Time);
#endif // ZEN_WITH_TESTS
private:
GcManager& m_Gc;
JobQueue& m_JobQueue;
std::filesystem::path m_RootDir;
Configuration m_Configuration;
ZenCacheDiskLayer m_DiskLayer;
std::atomic<uint64_t> m_HitCount{};
std::atomic<uint64_t> m_MissCount{};
std::atomic<uint64_t> m_WriteCount{};
metrics::RequestStats m_PutOps;
metrics::RequestStats m_GetOps;
uint64_t m_LastScrubTime = 0;
ZenCacheNamespace(const ZenCacheNamespace&) = delete;
ZenCacheNamespace& operator=(const ZenCacheNamespace&) = delete;
};
/** Cache store interface
This manages a set of namespaces used for derived data caching purposes.
*/
class ZenCacheStore final : public RefCounted, public StatsProvider
{
public:
static constexpr std::string_view DefaultNamespace =
"!default!"; // This is intentionally not a valid namespace name and will only be used for mapping when no namespace is given
static constexpr std::string_view NamespaceDiskPrefix = "ns_";
struct Configuration
{
ZenCacheNamespace::Configuration NamespaceConfig;
bool AllowAutomaticCreationOfNamespaces = false;
struct LogConfig
{
bool EnableWriteLog = true;
bool EnableAccessLog = true;
} Logging;
};
struct Info
{
std::filesystem::path BasePath;
Configuration Config;
std::vector<std::string> NamespaceNames;
uint64_t DiskEntryCount = 0;
GcStorageSize StorageSize;
};
struct NamedNamespaceStats
{
std::string NamespaceName;
ZenCacheNamespace::NamespaceStats Stats;
};
struct CacheStoreStats
{
uint64_t HitCount = 0;
uint64_t MissCount = 0;
uint64_t WriteCount = 0;
uint64_t RejectedWriteCount = 0;
uint64_t RejectedReadCount = 0;
metrics::RequestStatsSnapshot PutOps;
metrics::RequestStatsSnapshot GetOps;
std::vector<NamedNamespaceStats> NamespaceStats;
};
ZenCacheStore(GcManager& Gc,
JobQueue& JobQueue,
const std::filesystem::path& BasePath,
const Configuration& Configuration,
const DiskWriteBlocker* InDiskWriteBlocker);
~ZenCacheStore();
bool Get(const CacheRequestContext& Context,
std::string_view Namespace,
std::string_view Bucket,
const IoHash& HashKey,
ZenCacheValue& OutValue);
void Put(const CacheRequestContext& Context,
std::string_view Namespace,
std::string_view Bucket,
const IoHash& HashKey,
const ZenCacheValue& Value,
std::span<IoHash> References);
bool DropBucket(std::string_view Namespace, std::string_view Bucket);
bool DropNamespace(std::string_view Namespace);
void Flush();
void ScrubStorage(ScrubContext& Ctx);
CacheValueDetails GetValueDetails(const std::string_view NamespaceFilter,
const std::string_view BucketFilter,
const std::string_view ValueFilter) const;
GcStorageSize StorageSize() const;
CacheStoreStats Stats(bool IncludeNamespaceStats = true);
Configuration GetConfiguration() const { return m_Configuration; }
void SetLoggingConfig(const Configuration::LogConfig& Loggingconfig);
Info GetInfo() const;
std::optional<ZenCacheNamespace::Info> GetNamespaceInfo(std::string_view Namespace);
std::optional<ZenCacheNamespace::BucketInfo> GetBucketInfo(std::string_view Namespace, std::string_view Bucket);
std::vector<std::string> GetNamespaces();
void EnumerateBucketContents(std::string_view Namespace,
std::string_view Bucket,
std::function<void(const IoHash& Key, const CacheValueDetails::ValueDetails& Details)>&& Fn);
// StatsProvider
virtual void ReportMetrics(StatsMetrics& Statsd) override;
private:
const ZenCacheNamespace* FindNamespace(std::string_view Namespace) const;
ZenCacheNamespace* GetNamespace(std::string_view Namespace);
void IterateNamespaces(const std::function<void(std::string_view Namespace, ZenCacheNamespace& Store)>& Callback) const;
typedef std::unordered_map<std::string, std::unique_ptr<ZenCacheNamespace>> NamespaceMap;
CacheStoreStats m_LastReportedMetrics;
const DiskWriteBlocker* m_DiskWriteBlocker = nullptr;
mutable RwLock m_NamespacesLock;
NamespaceMap m_Namespaces;
std::vector<std::unique_ptr<ZenCacheNamespace>> m_DroppedNamespaces;
GcManager& m_Gc;
JobQueue& m_JobQueue;
std::filesystem::path m_BasePath;
Configuration m_Configuration;
std::atomic<uint64_t> m_HitCount{};
std::atomic<uint64_t> m_MissCount{};
std::atomic<uint64_t> m_WriteCount{};
std::atomic<uint64_t> m_RejectedWriteCount{};
std::atomic<uint64_t> m_RejectedReadCount{};
metrics::RequestStats m_PutOps;
metrics::RequestStats m_GetOps;
struct AccessLogItem
{
const char* Op;
CacheRequestContext Context;
std::string Namespace;
std::string Bucket;
IoHash HashKey;
ZenCacheValue Value;
};
void LogWorker();
RwLock m_LogQueueLock;
std::vector<AccessLogItem> m_LogQueue;
std::atomic_bool m_ExitLogging;
Event m_LogEvent;
std::thread m_AsyncLoggingThread;
std::atomic_bool m_WriteLogEnabled;
std::atomic_bool m_AccessLogEnabled;
};
void z$_forcelink();
} // namespace zen
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