bolt 是一款高性能的key value 数据库，下面是它的使用示例：
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package main
import (
"encoding/binary"
"encoding/json"
"fmt"
"log"
"time"
"github.com/boltdb/bolt"
)
type Post struct {
Created time.Time
Title string
Content string
}
type User struct {
ID int
Name string
}
func main() {
db, err := bolt.Open("my.db", 0600, &bolt.Options{Timeout: 1 * time.Second})
if err != nil {
log.Fatal(err)
}
defer db.Close()
/*
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucketIfNotExists([]byte("posts"))
if err != nil {
return err
}
return b.Put([]byte("2015-01-01"), []byte("My New Year post"))
})
*/
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("posts"))
v := b.Get([]byte("2015-01-01"))
fmt.Printf("%s\n", v)
if err := b.ForEach(func(k, v []byte) error {
fmt.Printf("A %s is %s.\n", k, v)
return nil
}); err != nil {
return err
}
return nil
})
post := &Post{
Created: time.Now(),
Title: "My first post",
Content: "Hello, this is my first post.",
}
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucketIfNotExists([]byte("posts"))
if err != nil {
return err
}
encoded, err := json.Marshal(post)
if err != nil {
return err
}
return b.Put([]byte(post.Created.Format(time.RFC3339)), encoded)
})
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucketIfNotExists([]byte("posts"))
if err != nil {
return err
}
encoded, err := json.Marshal(post)
if err != nil {
return err
}
return b.Put([]byte(post.Created.Format(time.RFC3339)), encoded)
})
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucketIfNotExists([]byte("MyBucket"))
err = b.Put([]byte("answer"), []byte("42"))
return err
})
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("MyBucket"))
v := b.Get([]byte("answer"))
fmt.Printf("%s\n", v)
return nil
})
db.Update(func(tx *bolt.Tx) error {
u := User{}
// Retrieve the users bucket.
// This should be created when the DB is first opened.
//b := tx.Bucket([]byte("users"))
b, err := tx.CreateBucketIfNotExists([]byte("users"))
// Generate ID for the user.
// This returns an error only if the Tx is closed or not writeable.
// That can't happen in an Update() call so I ignore the error check.
id, _ := b.NextSequence()
u.ID = int(id)
// Marshal user data into bytes.
buf, err := json.Marshal(u)
if err != nil {
return err
}
// Persist bytes to users bucket.
return b.Put(itob(u.ID), buf)
})
// Delete the key in a different write transaction.
if err := db.Update(func(tx *bolt.Tx) error {
return tx.Bucket([]byte("MyBucket")).Delete([]byte("answer"))
}); err != nil {
log.Fatal(err)
}
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("users"))
if err := b.ForEach(func(k, v []byte) error {
fmt.Printf("A %s is %s.\n", k, v)
return nil
}); err != nil {
return err
}
return nil
})
}
// itob returns an 8-byte big endian representation of v.
func itob(v int) []byte {
b := make([]byte, 8)
binary.BigEndian.PutUint64(b, uint64(v))
return b
}
官方网站 https://github.com/boltdb/bolt
官方示例 https://godoc.org/github.com/boltdb/bolt#pkg-examples
本站就是使用 boltdb 作为底层数据库。
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