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
|
// Copyright 2021-2021 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package server
import (
"sync"
"time"
)
type rateCounter struct {
limit int64
count int64
blocked uint64
end time.Time
interval time.Duration
mu sync.Mutex
}
func newRateCounter(limit int64) *rateCounter {
return &rateCounter{
limit: limit,
interval: time.Second,
}
}
func (r *rateCounter) allow() bool {
now := time.Now()
r.mu.Lock()
if now.After(r.end) {
r.count = 0
r.end = now.Add(r.interval)
} else {
r.count++
}
allow := r.count < r.limit
if !allow {
r.blocked++
}
r.mu.Unlock()
return allow
}
func (r *rateCounter) countBlocked() uint64 {
r.mu.Lock()
blocked := r.blocked
r.blocked = 0
r.mu.Unlock()
return blocked
}
|
