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{}}
+}

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

@@ -0,0 +1,67 @@
+package driver
+
+import (
+	"errors"
+)
+
+var (
+	ErrTxSupport = errors.New("transaction is not supported")
+)
+
+type IDB interface {
+	Close() error
+
+	Get(key []byte) ([]byte, error)
+
+	Put(key []byte, value []byte) error
+	Delete(key []byte) error
+
+	NewIterator() IIterator
+
+	NewWriteBatch() IWriteBatch
+
+	NewSnapshot() (ISnapshot, error)
+
+	Begin() (Tx, error)
+}
+
+type ISnapshot interface {
+	Get(key []byte) ([]byte, error)
+	NewIterator() IIterator
+	Close()
+}
+
+type IIterator interface {
+	Close() error
+
+	First()
+	Last()
+	Seek(key []byte)
+
+	Next()
+	Prev()
+
+	Valid() bool
+
+	Key() []byte
+	Value() []byte
+}
+
+type IWriteBatch interface {
+	Put(key []byte, value []byte)
+	Delete(key []byte)
+	Commit() error
+	Rollback() error
+}
+
+type Tx interface {
+	Get(key []byte) ([]byte, error)
+	Put(key []byte, value []byte) error
+	Delete(key []byte) error
+
+	NewIterator() IIterator
+	NewWriteBatch() IWriteBatch
+
+	Commit() error
+	Rollback() error
+}

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

@@ -0,0 +1,46 @@
+package driver
+
+import (
+	"fmt"
+
+	"github.com/lunny/nodb/config"
+)
+
+type Store interface {
+	String() string
+	Open(path string, cfg *config.Config) (IDB, error)
+	Repair(path string, cfg *config.Config) error
+}
+
+var dbs = map[string]Store{}
+
+func Register(s Store) {
+	name := s.String()
+	if _, ok := dbs[name]; ok {
+		panic(fmt.Errorf("store %s is registered", s))
+	}
+
+	dbs[name] = s
+}
+
+func ListStores() []string {
+	s := []string{}
+	for k, _ := range dbs {
+		s = append(s, k)
+	}
+
+	return s
+}
+
+func GetStore(cfg *config.Config) (Store, error) {
+	if len(cfg.DBName) == 0 {
+		cfg.DBName = config.DefaultDBName
+	}
+
+	s, ok := dbs[cfg.DBName]
+	if !ok {
+		return nil, fmt.Errorf("store %s is not registered", cfg.DBName)
+	}
+
+	return s, nil
+}