97 lines
1.9 KiB
Go
97 lines
1.9 KiB
Go
package lmdb
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"encoding/hex"
|
|
"fmt"
|
|
|
|
"github.com/ledgerwatch/lmdb-go/lmdb"
|
|
)
|
|
|
|
const (
|
|
DefaultIndexPrefix = "indexes/"
|
|
)
|
|
|
|
var (
|
|
ErrIndexKeyNotFound = fmt.Errorf("key is not found in the index")
|
|
)
|
|
|
|
type Index struct {
|
|
name string
|
|
dbEnv *lmdb.Env
|
|
db lmdb.DBI
|
|
}
|
|
|
|
func NewIndex(name string, dbEnv *lmdb.Env, db lmdb.DBI) *Index {
|
|
return &Index{
|
|
name: name,
|
|
db: db,
|
|
dbEnv: dbEnv,
|
|
}
|
|
}
|
|
|
|
func (i *Index) PutUint64(key []byte, value uint64) error {
|
|
return i.dbEnv.Update(func(txn *lmdb.Txn) error {
|
|
data := make([]byte, 8)
|
|
binary.LittleEndian.PutUint64(data, value)
|
|
return txn.Put(i.db, i.constructIndexKey(key), data, 0)
|
|
})
|
|
}
|
|
|
|
func (i *Index) GetUint64(key []byte) (uint64, error) {
|
|
var num uint64
|
|
err := i.dbEnv.View(func(txn *lmdb.Txn) error {
|
|
data, err := txn.Get(i.db, i.constructIndexKey(key))
|
|
if err != nil {
|
|
if lmdb.IsNotFound(err) {
|
|
return ErrIndexKeyNotFound
|
|
}
|
|
return err
|
|
}
|
|
num = binary.LittleEndian.Uint64(data)
|
|
return nil
|
|
})
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
return num, nil
|
|
}
|
|
|
|
func (i *Index) PutBytes(key []byte, value []byte) error {
|
|
return i.dbEnv.Update(func(txn *lmdb.Txn) error {
|
|
return txn.Put(i.db, i.constructIndexKey(key), value, 0)
|
|
})
|
|
}
|
|
|
|
func (i *Index) GetBytes(key []byte) ([]byte, error) {
|
|
var data []byte
|
|
err := i.dbEnv.View(func(txn *lmdb.Txn) error {
|
|
valueData, err := txn.Get(i.db, i.constructIndexKey(key))
|
|
if err != nil {
|
|
if lmdb.IsNotFound(err) {
|
|
return ErrIndexKeyNotFound
|
|
}
|
|
return err
|
|
}
|
|
data = valueData
|
|
return nil
|
|
})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return data, nil
|
|
}
|
|
|
|
func (i *Index) Delete(key []byte) error {
|
|
return i.dbEnv.Update(func(txn *lmdb.Txn) error {
|
|
return txn.Del(i.db, i.constructIndexKey(key), nil)
|
|
})
|
|
}
|
|
|
|
func (i *Index) constructIndexKey(key []byte) []byte {
|
|
k := hex.EncodeToString(key)
|
|
return []byte(fmt.Sprintf("%s/%s/%s", DefaultIndexPrefix, i.name, k))
|
|
}
|