-
Notifications
You must be signed in to change notification settings - Fork 82
/
reconnpolicy.go
78 lines (67 loc) · 1.9 KB
/
reconnpolicy.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
// Copyright (c) DataStax, Inc.
//
// 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 proxycore
import (
"math/bits"
"math/rand"
"time"
)
const (
defaultBaseDelay = 2 * time.Second
defaultMaxDelay = 10 * time.Minute
)
type ReconnectPolicy interface {
NextDelay() time.Duration
Reset()
Clone() ReconnectPolicy
}
type defaultReconnectPolicy struct {
attempts int
maxAttempts int
baseDelay time.Duration
maxDelay time.Duration
}
func NewReconnectPolicy() ReconnectPolicy {
return NewReconnectPolicyWithDelays(defaultBaseDelay, defaultMaxDelay)
}
func NewReconnectPolicyWithDelays(baseDelay, maxDelay time.Duration) ReconnectPolicy {
return &defaultReconnectPolicy{
attempts: 0,
maxAttempts: calcMaxAttempts(baseDelay),
baseDelay: baseDelay,
maxDelay: maxDelay,
}
}
func (d *defaultReconnectPolicy) NextDelay() time.Duration {
if d.attempts >= d.maxAttempts {
return d.maxDelay
}
jitter := time.Duration(rand.Intn(30)+85) * time.Millisecond
exp := time.Millisecond << d.attempts
d.attempts++
delay := d.baseDelay + exp + jitter
if delay > d.maxDelay {
delay = d.maxDelay
}
return delay
}
func (d *defaultReconnectPolicy) Reset() {
d.attempts = 0
}
func (d defaultReconnectPolicy) Clone() ReconnectPolicy {
return NewReconnectPolicyWithDelays(d.baseDelay, d.maxDelay)
}
func calcMaxAttempts(baseDelay time.Duration) int {
return 63 - bits.LeadingZeros64(uint64(baseDelay))
}