-
Notifications
You must be signed in to change notification settings - Fork 1
/
reader.go
131 lines (110 loc) · 2.77 KB
/
reader.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
// Copyright (c) 2020 anatolygudkov. All rights reserved.
// Use of this source code is governed by MIT license
// that can be found in the LICENSE file.
package mc4go
import (
"errors"
"fmt"
"os"
"os/user"
"path"
"runtime"
"github.com/anatolygudkov/mc4go/internal/layout"
"github.com/anatolygudkov/mc4go/internal/mmap"
"github.com/anatolygudkov/mc4go/internal/offheap"
)
// GetMCountersDirectoryPath returns
func GetMCountersDirectoryPath() (p string) {
p = os.Getenv("mcounters.dir")
if p != "" {
return
}
baseDir := ""
if runtime.GOOS == `linux` {
shm := "/dev/shm"
_, err := os.Stat(shm)
if err == nil {
baseDir = shm
}
}
if baseDir == "" {
baseDir = os.TempDir()
}
username := "default"
u, err := user.Current()
if err == nil {
if u.Username != "" {
username = u.Username
}
}
p = path.Join(baseDir, "mcounters-"+username)
return
}
// Reader reads
type Reader struct {
buffer *offheap.Buffer
decoder *layout.Decoder
}
// NewReader creates
func NewReader(buf *offheap.Buffer) (r *Reader, err error) {
decoder := layout.NewDecoder(buf)
version := decoder.Version()
if version == 0 {
return nil, errors.New("counters haven't been initialized yet")
}
if version != layout.CountersVersion {
return nil, fmt.Errorf("unexpected version of the counters file: %d", version)
}
return &Reader{
buffer: buf,
decoder: decoder,
}, nil
}
// NewReaderForFile creates
func NewReaderForFile(filename string) (r *Reader, err error) {
buf, err := mmap.MapExistingFileReadOnly(filename)
if err != nil {
return nil, err
}
return NewReader(buf)
}
// NewReaderForName creates
func NewReaderForName(name string) (r *Reader, err error) {
return NewReaderForFile(path.Join(GetMCountersDirectoryPath(), name))
}
// Version returns
func (r *Reader) Version() int32 {
return r.decoder.Version()
}
// Pid returns
func (r *Reader) Pid() int64 {
return r.decoder.Pid()
}
// StartTime returns
func (r *Reader) StartTime() int64 {
return r.decoder.StartTime()
}
// ForEachStatic returns
func (r *Reader) ForEachStatic(consumer func(label, value string) bool) {
r.decoder.ForEachStatic(consumer)
}
// GetStaticValue returns
func (r *Reader) GetStaticValue(label string) (v string, err error) {
return r.decoder.GetStaticValue(label)
}
// ForEachCounter returns
func (r *Reader) ForEachCounter(consumer func(id, value int64, label string) bool) {
r.decoder.ForEachCounter(consumer)
}
// GetCounterValue returns
func (r *Reader) GetCounterValue(counterID int64) (value int64, err error) {
return r.decoder.GetCounterValue(counterID)
}
// GetCounterLabel returns
func (r *Reader) GetCounterLabel(counterID int64) (label string, err error) {
return r.decoder.GetCounterLabel(counterID)
}
// Close returns
func (r *Reader) Close() (err error) {
return mmap.Unmap(r.buffer)
}