72 lines
1.7 KiB
Go
72 lines
1.7 KiB
Go
package state
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"encoding/hex"
|
|
"fmt"
|
|
|
|
"go.etcd.io/bbolt"
|
|
)
|
|
|
|
// PersistentStorage is a wrapper around persistent K:V db that
|
|
// provides thread safe functions to set and fetch state variables
|
|
// of the Inner Ring and Storage applications.
|
|
type PersistentStorage struct {
|
|
db *bbolt.DB
|
|
}
|
|
|
|
var stateBucket = []byte("state")
|
|
|
|
// NewPersistentStorage creates a new instance of a storage with 0600 rights.
|
|
func NewPersistentStorage(path string) (*PersistentStorage, error) {
|
|
db, err := bbolt.Open(path, 0o600, nil)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("can't open bbolt at %s: %w", path, err)
|
|
}
|
|
|
|
return &PersistentStorage{db: db}, nil
|
|
}
|
|
|
|
// SetUInt32 sets a uint32 value in the storage.
|
|
func (p PersistentStorage) SetUInt32(key []byte, value uint32) error {
|
|
return p.db.Update(func(tx *bbolt.Tx) error {
|
|
b, err := tx.CreateBucketIfNotExists(stateBucket)
|
|
if err != nil {
|
|
return fmt.Errorf("can't create state bucket in state persistent storage: %w", err)
|
|
}
|
|
|
|
buf := make([]byte, 8)
|
|
binary.LittleEndian.PutUint64(buf, uint64(value))
|
|
|
|
return b.Put(key, buf)
|
|
})
|
|
}
|
|
|
|
// UInt32 returns a uint32 value from persistent storage. If the value does not exist,
|
|
// returns 0.
|
|
func (p PersistentStorage) UInt32(key []byte) (n uint32, err error) {
|
|
err = p.db.View(func(tx *bbolt.Tx) error {
|
|
b := tx.Bucket(stateBucket)
|
|
if b == nil {
|
|
return nil // if bucket not exists yet, return default n = 0
|
|
}
|
|
|
|
buf := b.Get(key)
|
|
if len(buf) != 8 {
|
|
return fmt.Errorf("persistent storage does not store uint data in %s", hex.EncodeToString(key))
|
|
}
|
|
|
|
u64 := binary.LittleEndian.Uint64(buf)
|
|
n = uint32(u64)
|
|
|
|
return nil
|
|
})
|
|
|
|
return
|
|
}
|
|
|
|
// Close closes persistent database instance.
|
|
func (p PersistentStorage) Close() error {
|
|
return p.db.Close()
|
|
}
|