storage manager 添加open方法

storage/storage.go

@@ -2,6 +2,8 @@ package storage
 
 import (
 	"fmt"
+	"io/ioutil"
+	"os"
 	"sync"
 )
 
@@ -72,6 +74,39 @@ func (sm *StorageManager) GetStorage(dbName string) (*LevelDBStorage, error) {
 	return sm.db[dbName], nil
 }
 
+func (sm *StorageManager) isLevelDB(dirp string) bool {
+	if _, err := os.Stat(dirp); os.IsNotExist(err) {
+		return false
+	}
+	files := []string{"CURRENT", "LOCK", "LOG", "LOG.old", "MANIFEST-"}
+	for _, file := range files {
+		if _, err := os.Stat(dirp + "/" + file); err == nil {
+			return true
+		}
+	}
+	return false
+}
+
+func (sm *StorageManager) Open() {
+	// 得到dbrootDir下的所有子目录
+	dirs, err := ioutil.ReadDir(sm.dbrootDir)
+	if err != nil {
+		panic(err)
+	}
+	for _, dir := range dirs {
+		if dir.IsDir() {
+			dbPath := sm.dbrootDir + "/" + dir.Name()
+			if sm.isLevelDB(dbPath) {
+				db, err := NewLevelDBStorage(dbPath)
+				if err != nil {
+					panic(err)
+				}
+				sm.db[dir.Name()] = db
+			}
+
+		}
+	}
+}
 func (sm *StorageManager) Close() {
 	for _, db := range sm.db {
 		db.Close()