forked from Conflux-Chain/confura
/
strategy.go
195 lines (155 loc) · 4.24 KB
/
strategy.go
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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
package rate
import (
"crypto/md5"
"fmt"
"time"
"github.com/sirupsen/logrus"
)
const (
// limit types
LimitTypeByKey = iota
LimitTypeByIp
)
// Strategy rate limit strategy
type Strategy struct {
ID uint32 // strategy ID
Name string // strategy name
Rules map[string]Option // limit rules: rule name => rule option
MD5 [md5.Size]byte `json:"-"` // config data fingerprint
}
// LimiterSet limiter set assembled by strategy
type LimiterSet interface {
Get(vc *VisitContext) (Limiter, bool)
GC(timeout time.Duration)
Update(s *Strategy)
}
// limiterCreator limiter factory method
type limiterCreator func(option Option) Limiter
type baseLimiterSet struct {
*Strategy // used strategy
uid string // unique identifier
lcreator limiterCreator // limiter factory
limiters map[string]Limiter // limit rule => Limiter
}
func newBaseLimiterSet(uid string, s *Strategy, lcreator limiterCreator) *baseLimiterSet {
limiters := make(map[string]Limiter, len(s.Rules))
for name, option := range s.Rules {
limiters[name] = lcreator(option)
}
return &baseLimiterSet{
Strategy: s, uid: uid, lcreator: lcreator, limiters: limiters,
}
}
// Get returns limiter for current visit context
func (ls *baseLimiterSet) Get(vc *VisitContext) (Limiter, bool) {
l, ok := ls.limiters[vc.Resource]
return l, ok
}
// GC garbage collects limiter stale resources
func (ls *baseLimiterSet) GC(timeout time.Duration) {
for _, l := range ls.limiters {
l.GC(timeout)
}
}
// Update updates with new strategy
func (ls *baseLimiterSet) Update(s *Strategy) {
// remove limit rules
for name, option := range ls.Rules {
if _, ok := s.Rules[name]; !ok {
logrus.WithFields(logrus.Fields{
"limiterSetUid": ls.uid,
"rule": name,
"option": option,
}).Info("Strategy rule removed")
delete(ls.limiters, name)
}
}
// add or update limit rules
for name, newOption := range s.Rules {
logger := logrus.WithFields(logrus.Fields{
"limiterSetUid": ls.uid,
"rule": name,
"option": newOption,
})
option, ok := ls.Rules[name]
if !ok { // add
logger.Info("Strategy rule added")
ls.limiters[name] = ls.lcreator(newOption)
continue
}
if newOption == option { // no change
continue
}
if l, ok := ls.limiters[name]; ok { // update
logger.Info("Strategy rule updated")
l.Update(newOption)
}
}
}
// IpLimiterSet limiting by IP address
type IpLimiterSet struct {
*baseLimiterSet
}
func NewIpLimiterSet(s *Strategy) *IpLimiterSet {
uid := fmt.Sprintf("IpLimiterSet-%s", s.Name)
base := newBaseLimiterSet(uid, s, func(option Option) Limiter {
return NewIpLimiter(option)
})
return &IpLimiterSet{baseLimiterSet: base}
}
// KeyLimiterSet limiting by key
type KeyLimiterSet struct {
*baseLimiterSet
}
func NewKeyLimiterSet(s *Strategy) *KeyLimiterSet {
uid := fmt.Sprintf("KeyLimiterSet-%s", s.Name)
base := newBaseLimiterSet(uid, s, func(option Option) Limiter {
return NewKeyLimiter(option)
})
return &KeyLimiterSet{baseLimiterSet: base}
}
// KeyBasedIpLimiterSet limiting by IP address yet grouped by limit key
type KeyBasedIpLimiterSet struct {
*baseLimiterSet
}
func NewKeyBasedIpLimiterSet(s *Strategy) *KeyBasedIpLimiterSet {
uid := fmt.Sprintf("KeyBasedIpLimiterSet-%s", s.Name)
base := newBaseLimiterSet(uid, s, func(option Option) Limiter {
return newkeyBasedIpLimiter(option)
})
return &KeyBasedIpLimiterSet{baseLimiterSet: base}
}
// keyBasedIpLimiter limits visits per IP address grouped by limit key
type keyBasedIpLimiter struct {
Option
// limit key => *IpLimiter
limiters map[string]*IpLimiter
}
func newkeyBasedIpLimiter(opt Option) *keyBasedIpLimiter {
return &keyBasedIpLimiter{
Option: opt, limiters: make(map[string]*IpLimiter),
}
}
func (ls *keyBasedIpLimiter) Allow(vc *VisitContext, n int) bool {
l, ok := ls.limiters[vc.Key]
if !ok {
l = NewIpLimiter(ls.Option)
ls.limiters[vc.Key] = l
}
return l.Allow(vc, n)
}
func (ls *keyBasedIpLimiter) GC(timeout time.Duration) {
for _, l := range ls.limiters {
l.GC(timeout)
}
}
func (ls *keyBasedIpLimiter) Update(opt Option) bool {
if ls.Rate == opt.Rate && ls.Burst == opt.Burst {
return false
}
for _, l := range ls.limiters {
l.Update(opt)
}
ls.Option = opt
return true
}