-
Notifications
You must be signed in to change notification settings - Fork 153
/
02_write_read.go
120 lines (107 loc) · 2.51 KB
/
02_write_read.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
package main
import (
"fmt"
"math/rand"
"os"
"time"
"github.com/boltdb/bolt"
"github.com/renstrom/shortuuid"
)
var (
dbPath = shortuuid.New() + ".db"
bucketName = shortuuid.New()
numKeys = 10
keyLen = 3
valLen = 7
keys = make([][]byte, numKeys)
vals = make([][]byte, numKeys)
)
func init() {
fmt.Println("Starting writing random data...")
for i := range keys {
keys[i] = randBytes(keyLen)
vals[i] = randBytes(valLen)
}
fmt.Println("Done with writing random data...")
}
func main() {
fmt.Println("dbPath:", dbPath)
fmt.Println("bucketName:", bucketName)
defer os.Remove(dbPath)
db, err := bolt.Open(dbPath, 0600, &bolt.Options{Timeout: 1 * time.Second})
if err != nil {
panic(err)
}
defer db.Close()
fmt.Println("Starting writing...")
if err := db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucket([]byte(bucketName))
if err != nil {
return err
}
for i := range keys {
if err := b.Put(keys[i], vals[i]); err != nil {
return err
}
}
return nil
}); err != nil {
panic(err)
}
fmt.Println("Done with writing...")
fmt.Println("Starting reading...")
if err := db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte(bucketName))
for i := range keys {
k := keys[i]
v := b.Get(k)
fmt.Printf("Read: %s ---> %s\n", k, v)
}
return nil
}); err != nil {
panic(err)
}
fmt.Println("Done with reading...")
}
/*
Starting writing random data...
Done with writing random data...
dbPath: MAD96XbjYFenxMQBSnMxvY.db
bucketName: zeXeJqUhpMhYD5kPVMRVBi
Starting writing...
Done with writing...
Starting reading...
Read: uWN ---> qpjxtgO
Read: vPH ---> kgBMOcz
Read: unX ---> XgGmeOJ
Read: gLd ---> ekPAyFk
Read: dVa ---> yjgXook
Read: otW ---> nyiOWvj
Read: rBV ---> viufTKO
Read: wto ---> NVFceGz
Read: Dtg ---> RlPULZS
Read: PLC ---> NqLporc
Done with reading...
*/
func randBytes(n int) []byte {
const (
letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
letterIdxBits = 6 // 6 bits to represent a letter index
letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
letterIdxMax = 63 / letterIdxBits // # of letter indices fitting in 63 bits
)
src := rand.NewSource(time.Now().UnixNano())
b := make([]byte, n)
for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; {
if remain == 0 {
cache, remain = src.Int63(), letterIdxMax
}
if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
b[i] = letterBytes[idx]
i--
}
cache >>= letterIdxBits
remain--
}
return b
}