/
gauge.go
176 lines (144 loc) · 4.48 KB
/
gauge.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
// Copyright Simcord LLC
// This file is part of the Bitbon System Blockchain Node library.
// This file has been modified, you can find the original version by following the link
// <https://github.com/ethereum/go-ethereum>
//
// The Bitbon System Blockchain Node library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The Bitbon System Blockchain Node library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the Bitbon System Blockchain Node library. If not, see <http://www.gnu.org/licenses/>.
package metrics
import "sync/atomic"
// Gauges hold an int64 value that can be set arbitrarily.
type Gauge interface {
Snapshot() Gauge
Update(int64)
Dec(int64)
Inc(int64)
Value() int64
}
// GetOrRegisterGauge returns an existing Gauge or constructs and registers a
// new StandardGauge.
func GetOrRegisterGauge(name string, r Registry) Gauge {
if r == nil {
r = DefaultRegistry
}
return r.GetOrRegister(name, NewGauge).(Gauge)
}
// NewGauge constructs a new StandardGauge.
func NewGauge() Gauge {
if !Enabled {
return NilGauge{}
}
return &StandardGauge{0}
}
// NewRegisteredGauge constructs and registers a new StandardGauge.
func NewRegisteredGauge(name string, r Registry) Gauge {
c := NewGauge()
if r == nil {
r = DefaultRegistry
}
r.Register(name, c)
return c
}
// NewFunctionalGauge constructs a new FunctionalGauge.
func NewFunctionalGauge(f func() int64) Gauge {
if !Enabled {
return NilGauge{}
}
return &FunctionalGauge{value: f}
}
// NewRegisteredFunctionalGauge constructs and registers a new StandardGauge.
func NewRegisteredFunctionalGauge(name string, r Registry, f func() int64) Gauge {
c := NewFunctionalGauge(f)
if r == nil {
r = DefaultRegistry
}
r.Register(name, c)
return c
}
// GaugeSnapshot is a read-only copy of another Gauge.
type GaugeSnapshot int64
// Snapshot returns the snapshot.
func (g GaugeSnapshot) Snapshot() Gauge { return g }
// Update panics.
func (GaugeSnapshot) Update(int64) {
panic("Update called on a GaugeSnapshot")
}
// Dec panics.
func (GaugeSnapshot) Dec(int64) {
panic("Dec called on a GaugeSnapshot")
}
// Inc panics.
func (GaugeSnapshot) Inc(int64) {
panic("Inc called on a GaugeSnapshot")
}
// Value returns the value at the time the snapshot was taken.
func (g GaugeSnapshot) Value() int64 { return int64(g) }
// NilGauge is a no-op Gauge.
type NilGauge struct{}
// Snapshot is a no-op.
func (NilGauge) Snapshot() Gauge { return NilGauge{} }
// Update is a no-op.
func (NilGauge) Update(v int64) {}
// Dec is a no-op.
func (NilGauge) Dec(i int64) {}
// Inc is a no-op.
func (NilGauge) Inc(i int64) {}
// Value is a no-op.
func (NilGauge) Value() int64 { return 0 }
// StandardGauge is the standard implementation of a Gauge and uses the
// sync/atomic package to manage a single int64 value.
type StandardGauge struct {
value int64
}
// Snapshot returns a read-only copy of the gauge.
func (g *StandardGauge) Snapshot() Gauge {
return GaugeSnapshot(g.Value())
}
// Update updates the gauge's value.
func (g *StandardGauge) Update(v int64) {
atomic.StoreInt64(&g.value, v)
}
// Value returns the gauge's current value.
func (g *StandardGauge) Value() int64 {
return atomic.LoadInt64(&g.value)
}
// Dec decrements the gauge's current value by the given amount.
func (g *StandardGauge) Dec(i int64) {
atomic.AddInt64(&g.value, -i)
}
// Inc increments the gauge's current value by the given amount.
func (g *StandardGauge) Inc(i int64) {
atomic.AddInt64(&g.value, i)
}
// FunctionalGauge returns value from given function
type FunctionalGauge struct {
value func() int64
}
// Value returns the gauge's current value.
func (g FunctionalGauge) Value() int64 {
return g.value()
}
// Snapshot returns the snapshot.
func (g FunctionalGauge) Snapshot() Gauge { return GaugeSnapshot(g.Value()) }
// Update panics.
func (FunctionalGauge) Update(int64) {
panic("Update called on a FunctionalGauge")
}
// Dec panics.
func (FunctionalGauge) Dec(int64) {
panic("Dec called on a FunctionalGauge")
}
// Inc panics.
func (FunctionalGauge) Inc(int64) {
panic("Inc called on a FunctionalGauge")
}