add other session providers (#5963)

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

@@ -0,0 +1,39 @@
+package driver
+
+type BatchPuter interface {
+	BatchPut([]Write) error
+}
+
+type Write struct {
+	Key   []byte
+	Value []byte
+}
+
+type WriteBatch struct {
+	batch BatchPuter
+	wb    []Write
+}
+
+func (w *WriteBatch) Put(key, value []byte) {
+	if value == nil {
+		value = []byte{}
+	}
+	w.wb = append(w.wb, Write{key, value})
+}
+
+func (w *WriteBatch) Delete(key []byte) {
+	w.wb = append(w.wb, Write{key, nil})
+}
+
+func (w *WriteBatch) Commit() error {
+	return w.batch.BatchPut(w.wb)
+}
+
+func (w *WriteBatch) Rollback() error {
+	w.wb = w.wb[0:0]
+	return nil
+}
+
+func NewWriteBatch(puter BatchPuter) IWriteBatch {
+	return &WriteBatch{puter, []Write{}}
+}