package orm import ( "database/sql" "fmt" "reflect" "sync" "time" ) // database driver constant int. type DriverType int const ( _ DriverType = iota // int enum type DR_MySQL // mysql DR_Sqlite // sqlite DR_Oracle // oracle DR_Postgres // pgsql ) // database driver string. type driver string // get type constant int of current driver.. func (d driver) Type() DriverType { a, _ := dataBaseCache.get(string(d)) return a.Driver } // get name of current driver func (d driver) Name() string { return string(d) } // check driver iis implemented Driver interface or not. var _ Driver = new(driver) var ( dataBaseCache = &_dbCache{cache: make(map[string]*alias)} drivers = map[string]DriverType{ "mysql": DR_MySQL, "postgres": DR_Postgres, "sqlite3": DR_Sqlite, } dbBasers = map[DriverType]dbBaser{ DR_MySQL: newdbBaseMysql(), DR_Sqlite: newdbBaseSqlite(), DR_Oracle: newdbBaseMysql(), DR_Postgres: newdbBasePostgres(), } ) // database alias cacher. type _dbCache struct { mux sync.RWMutex cache map[string]*alias } // add database alias with original name. func (ac *_dbCache) add(name string, al *alias) (added bool) { ac.mux.Lock() defer ac.mux.Unlock() if _, ok := ac.cache[name]; ok == false { ac.cache[name] = al added = true } return } // get database alias if cached. func (ac *_dbCache) get(name string) (al *alias, ok bool) { ac.mux.RLock() defer ac.mux.RUnlock() al, ok = ac.cache[name] return } // get default alias. func (ac *_dbCache) getDefault() (al *alias) { al, _ = ac.get("default") return } type alias struct { Name string Driver DriverType DriverName string DataSource string MaxIdleConns int MaxOpenConns int DB *sql.DB DbBaser dbBaser TZ *time.Location Engine string } func detectTZ(al *alias) { // orm timezone system match database // default use Local al.TZ = time.Local if al.DriverName == "sphinx" { return } switch al.Driver { case DR_MySQL: row := al.DB.QueryRow("SELECT TIMEDIFF(NOW(), UTC_TIMESTAMP)") var tz string row.Scan(&tz) if len(tz) >= 8 { if tz[0] != '-' { tz = "+" + tz } t, err := time.Parse("-07:00:00", tz) if err == nil { al.TZ = t.Location() } else { DebugLog.Printf("Detect DB timezone: %s %s\n", tz, err.Error()) } } // get default engine from current database row = al.DB.QueryRow("SELECT ENGINE, TRANSACTIONS FROM information_schema.engines WHERE SUPPORT = 'DEFAULT'") var engine string var tx bool row.Scan(&engine, &tx) if engine != "" { al.Engine = engine } else { engine = "INNODB" } case DR_Sqlite: al.TZ = time.UTC case DR_Postgres: row := al.DB.QueryRow("SELECT current_setting('TIMEZONE')") var tz string row.Scan(&tz) loc, err := time.LoadLocation(tz) if err == nil { al.TZ = loc } else { DebugLog.Printf("Detect DB timezone: %s %s\n", tz, err.Error()) } } } func addAliasWthDB(aliasName, driverName string, db *sql.DB) (*alias, error) { al := new(alias) al.Name = aliasName al.DriverName = driverName al.DB = db if dr, ok := drivers[driverName]; ok { al.DbBaser = dbBasers[dr] al.Driver = dr } else { return nil, fmt.Errorf("driver name `%s` have not registered", driverName) } err := db.Ping() if err != nil { return nil, fmt.Errorf("register db Ping `%s`, %s", aliasName, err.Error()) } if dataBaseCache.add(aliasName, al) == false { return nil, fmt.Errorf("db name `%s` already registered, cannot reuse", aliasName) } return al, nil } func AddAliasWthDB(aliasName, driverName string, db *sql.DB) error { _, err := addAliasWthDB(aliasName, driverName, db) return err } // Setting the database connect params. Use the database driver self dataSource args. func RegisterDataBase(aliasName, driverName, dataSource string, params ...int) error { var ( err error db *sql.DB al *alias ) db, err = sql.Open(driverName, dataSource) if err != nil { err = fmt.Errorf("register db `%s`, %s", aliasName, err.Error()) goto end } al, err = addAliasWthDB(aliasName, driverName, db) if err != nil { goto end } al.DataSource = dataSource detectTZ(al) for i, v := range params { switch i { case 0: SetMaxIdleConns(al.Name, v) case 1: SetMaxOpenConns(al.Name, v) } } end: if err != nil { if db != nil { db.Close() } DebugLog.Println(err.Error()) } return err } // Register a database driver use specify driver name, this can be definition the driver is which database type. func RegisterDriver(driverName string, typ DriverType) error { if t, ok := drivers[driverName]; ok == false { drivers[driverName] = typ } else { if t != typ { return fmt.Errorf("driverName `%s` db driver already registered and is other type\n", driverName) } } return nil } // Change the database default used timezone func SetDataBaseTZ(aliasName string, tz *time.Location) error { if al, ok := dataBaseCache.get(aliasName); ok { al.TZ = tz } else { return fmt.Errorf("DataBase name `%s` not registered\n", aliasName) } return nil } // Change the max idle conns for *sql.DB, use specify database alias name func SetMaxIdleConns(aliasName string, maxIdleConns int) { al := getDbAlias(aliasName) al.MaxIdleConns = maxIdleConns al.DB.SetMaxIdleConns(maxIdleConns) } // Change the max open conns for *sql.DB, use specify database alias name func SetMaxOpenConns(aliasName string, maxOpenConns int) { al := getDbAlias(aliasName) al.MaxOpenConns = maxOpenConns // for tip go 1.2 if fun := reflect.ValueOf(al.DB).MethodByName("SetMaxOpenConns"); fun.IsValid() { fun.Call([]reflect.Value{reflect.ValueOf(maxOpenConns)}) } }