80 lines
1.4 KiB
Go
80 lines
1.4 KiB
Go
package storage
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import (
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"fmt"
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"sync"
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)
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type DbPolicy int
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const (
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DbPolicy_Tidy DbPolicy = iota // all store in one db
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DbPolicy_Loosy // store in different db
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)
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const (
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DefaultDbName = "default"
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)
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type StorageManager struct {
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policy DbPolicy
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dbrootDir string
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db map[string]*LevelDBStorage
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}
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var (
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instance *StorageManager
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once sync.Once
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)
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// 修改工厂函数实现单例模式
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func NewStorageManager(dbrootDir string, dbPolicy int) (*StorageManager, error) {
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var initErr error
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once.Do(func() {
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instance = &StorageManager{
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policy: DbPolicy(dbPolicy),
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dbrootDir: dbrootDir,
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db: make(map[string]*LevelDBStorage),
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}
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// 预初始化默认数据库
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if _, err := instance.GetStorage(DefaultDbName); err != nil {
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initErr = err
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}
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})
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if initErr != nil {
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return nil, initErr
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}
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return instance, nil
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}
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// 新增获取单例实例的方法
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func GetInstance() *StorageManager {
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return instance
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}
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func (sm *StorageManager) GetStorage(dbName string) (*LevelDBStorage, error) {
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if dbName == "" {
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return nil, fmt.Errorf("db name is empty")
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}
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if sm.policy == DbPolicy_Tidy {
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dbName = DefaultDbName
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}
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_, exists := sm.db[dbName]
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if !exists {
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db, err := NewLevelDBStorage(sm.dbrootDir + "/" + dbName)
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if err != nil {
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return nil, err
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}
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sm.db[dbName] = db
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}
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return sm.db[dbName], nil
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}
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func (sm *StorageManager) Close() {
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for _, db := range sm.db {
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db.Close()
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}
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}
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