add other session providers (#5963)

vendor/github.com/lunny/nodb/store/goleveldb/batch.go

@@ -0,0 +1,27 @@
+package goleveldb
+
+import (
+	"github.com/syndtr/goleveldb/leveldb"
+)
+
+type WriteBatch struct {
+	db     *DB
+	wbatch *leveldb.Batch
+}
+
+func (w *WriteBatch) Put(key, value []byte) {
+	w.wbatch.Put(key, value)
+}
+
+func (w *WriteBatch) Delete(key []byte) {
+	w.wbatch.Delete(key)
+}
+
+func (w *WriteBatch) Commit() error {
+	return w.db.db.Write(w.wbatch, nil)
+}
+
+func (w *WriteBatch) Rollback() error {
+	w.wbatch.Reset()
+	return nil
+}