status-go/db/storage.go

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package db
import (
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/iterator"
"github.com/syndtr/goleveldb/leveldb/storage"
"github.com/syndtr/goleveldb/leveldb/util"
)
// Storage is an interface for common db operations.
type Storage interface {
Put([]byte, []byte) error
Delete([]byte) error
Get([]byte) ([]byte, error)
NewIterator(*util.Range) iterator.Iterator
}
// CommitStorage allows to write all tx/batched values atomically.
type CommitStorage interface {
Storage
Commit() error
}
// TransactionalStorage adds transaction features on top of regular storage.
type TransactionalStorage interface {
Storage
NewTx() CommitStorage
}
// NewMemoryLevelDBStorage returns LevelDBStorage instance with in memory leveldb backend.
func NewMemoryLevelDBStorage() (LevelDBStorage, error) {
mdb, err := leveldb.Open(storage.NewMemStorage(), nil)
if err != nil {
return LevelDBStorage{}, err
}
return NewLevelDBStorage(mdb), nil
}
// NewLevelDBStorage creates new LevelDBStorage instance.
func NewLevelDBStorage(db *leveldb.DB) LevelDBStorage {
return LevelDBStorage{db: db}
}
// LevelDBStorage wrapper around leveldb.DB.
type LevelDBStorage struct {
db *leveldb.DB
}
// Put upserts given key/value pair.
func (db LevelDBStorage) Put(key, buf []byte) error {
return db.db.Put(key, buf, nil)
}
// Delete removes given key from database..
func (db LevelDBStorage) Delete(key []byte) error {
return db.db.Delete(key, nil)
}
// Get returns value for a given key.
func (db LevelDBStorage) Get(key []byte) ([]byte, error) {
return db.db.Get(key, nil)
}
// NewIterator returns new leveldb iterator.Iterator instance for a given range.
func (db LevelDBStorage) NewIterator(slice *util.Range) iterator.Iterator {
return db.db.NewIterator(slice, nil)
}
// NewTx is a wrapper around leveldb.Batch that allows to write atomically.
func (db LevelDBStorage) NewTx() CommitStorage {
return LevelDBTx{
batch: &leveldb.Batch{},
db: db,
}
}