bolt 作者提供的 boltdb 优化思路
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Be sure to check errors from `View()` and `Update()`. For example, there's a missing error check in NewList().
It's more efficient to use `binary.BigEndian.PutUint64()` instead of `fmt.Sprintf()` to represent ids.
For one thing, it's much faster to encode & decode.
Second of all, when you use a stringified representation then it won't insert sequentially.
官方的一个栗子：
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// CreateUser saves u to the store. The new user ID is set on u once the data is persisted.
func (s *Store) CreateUser(u *User) error {
return s.db.Update(func(tx *bolt.Tx) error {
// Retrieve the users bucket.
// This should be created when the DB is first opened.
b := tx.Bucket([]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)
})
}
// 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
}
type User struct {
ID int
...
}
byte to int 相互转换：
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func Btoi(b []byte) int {
s0, _ := strconv.Atoi(string(b))
return s0
}
func Itob(i int) []byte {
return []byte(strconv.Itoa(i))
}
另外一个，使用字节
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func itob(v int64) []byte {
b := make([]byte, 8)
binary.BigEndian.PutUint64(b, uint64(v))
return b
}
func btoi(v []byte) int64 {
return int64(binary.BigEndian.Uint64(v))
}
时间戳还原：
1timestamp := time.Unix(int64(binary.BigEndian.Uint64(v)), 0)