1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
#include <zencore/compactbinary.h>
#include <zencore/iobuffer.h>
#include <zencore/iohash.h>
#include <zencore/thread.h>
#include <zencore/uid.h>
#include <zenstore/basicfile.h>
#include <zenstore/cas.h>
#include <zenstore/caslog.h>
#include <zenstore/gc.h>
ZEN_THIRD_PARTY_INCLUDES_START
#include <tsl/robin_map.h>
ZEN_THIRD_PARTY_INCLUDES_END
#include <atomic>
#include <compare>
#include <filesystem>
#include <unordered_map>
namespace zen {
class CasStore;
class CasGc;
class WideStringBuilderBase;
class ZenCacheTracker;
/******************************************************************************
/$$$$$$$$ /$$$$$$ /$$
|_____ $$ /$$__ $$ | $$
/$$/ /$$$$$$ /$$$$$$$ | $$ \__/ /$$$$$$ /$$$$$$| $$$$$$$ /$$$$$$
/$$/ /$$__ $| $$__ $$ | $$ |____ $$/$$_____| $$__ $$/$$__ $$
/$$/ | $$$$$$$| $$ \ $$ | $$ /$$$$$$| $$ | $$ \ $| $$$$$$$$
/$$/ | $$_____| $$ | $$ | $$ $$/$$__ $| $$ | $$ | $| $$_____/
/$$$$$$$| $$$$$$| $$ | $$ | $$$$$$| $$$$$$| $$$$$$| $$ | $| $$$$$$$
|________/\_______|__/ |__/ \______/ \_______/\_______|__/ |__/\_______/
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).
******************************************************************************/
struct ZenCacheValue
{
IoBuffer Value;
CbObject IndexData;
};
/** In-memory cache storage
Intended for small values which are frequently accessed
This should have a better memory management policy to maintain reasonable
footprint.
*/
class ZenCacheMemoryLayer
{
public:
ZenCacheMemoryLayer();
~ZenCacheMemoryLayer();
bool Get(std::string_view Bucket, const IoHash& HashKey, ZenCacheValue& OutValue);
void Put(std::string_view Bucket, const IoHash& HashKey, const ZenCacheValue& Value);
bool DropBucket(std::string_view Bucket);
void Scrub(ScrubContext& Ctx);
void GatherReferences(GcContext& GcCtx);
uint64_t TotalSize() const;
struct Configuration
{
uint64_t TargetFootprintBytes = 16 * 1024 * 1024;
uint64_t ScavengeThreshold = 4 * 1024 * 1024;
};
const Configuration& GetConfiguration() const { return m_Configuration; }
void SetConfiguration(const Configuration& NewConfig) { m_Configuration = NewConfig; }
private:
struct CacheBucket
{
struct BucketValue
{
uint64_t LastAccess = 0;
IoBuffer Payload;
};
RwLock m_bucketLock;
tsl::robin_map<IoHash, BucketValue> m_cacheMap;
bool Get(const IoHash& HashKey, ZenCacheValue& OutValue);
void Put(const IoHash& HashKey, const ZenCacheValue& Value);
void Scrub(ScrubContext& Ctx);
void GatherReferences(GcContext& GcCtx);
inline uint64_t TotalSize() const { return m_TotalSize; }
private:
uint64_t GetCurrentTimeStamp();
std::atomic_uint64_t m_TotalSize{};
};
mutable RwLock m_Lock;
std::unordered_map<std::string, CacheBucket> m_Buckets;
Configuration m_Configuration;
ZenCacheMemoryLayer(const ZenCacheMemoryLayer&) = delete;
ZenCacheMemoryLayer& operator=(const ZenCacheMemoryLayer&) = delete;
};
class ZenCacheDiskLayer
{
public:
explicit ZenCacheDiskLayer(const std::filesystem::path& RootDir);
~ZenCacheDiskLayer();
bool Get(std::string_view Bucket, const IoHash& HashKey, ZenCacheValue& OutValue);
void Put(std::string_view Bucket, const IoHash& HashKey, const ZenCacheValue& Value);
bool DropBucket(std::string_view Bucket);
void Flush();
void Scrub(ScrubContext& Ctx);
void GatherReferences(GcContext& GcCtx);
void DiscoverBuckets();
uint64_t TotalSize() const;
private:
/** A cache bucket manages a single directory containing
metadata and data for that bucket
*/
struct CacheBucket;
std::filesystem::path m_RootDir;
mutable RwLock m_Lock;
std::unordered_map<std::string, CacheBucket> m_Buckets; // TODO: make this case insensitive
ZenCacheDiskLayer(const ZenCacheDiskLayer&) = delete;
ZenCacheDiskLayer& operator=(const ZenCacheDiskLayer&) = delete;
};
struct ZenCacheSize
{
uint64_t MemorySize{};
uint64_t DiskSize{};
};
class ZenCacheStore : public GcContributor
{
public:
ZenCacheStore(CasGc& Gc, const std::filesystem::path& RootDir);
~ZenCacheStore();
bool Get(std::string_view Bucket, const IoHash& HashKey, ZenCacheValue& OutValue);
void Put(std::string_view Bucket, const IoHash& HashKey, const ZenCacheValue& Value);
bool DropBucket(std::string_view Bucket);
void Flush();
void Scrub(ScrubContext& Ctx);
virtual void GatherReferences(GcContext& GcCtx) override;
ZenCacheSize TotalSize() const;
uint64_t DiskLayerThreshold() const { return m_DiskLayerSizeThreshold; }
private:
std::filesystem::path m_RootDir;
ZenCacheMemoryLayer m_MemLayer;
ZenCacheDiskLayer m_DiskLayer;
uint64_t m_DiskLayerSizeThreshold = 1 * 1024;
uint64_t m_LastScrubTime = 0;
std::unique_ptr<ZenCacheTracker> m_AccessTracker;
ZenCacheStore(const ZenCacheStore&) = delete;
ZenCacheStore& operator=(const ZenCacheStore&) = delete;
};
void z$_forcelink();
} // namespace zen
|