Golang mysql.NewError函數代碼示例

func (s *Server) onConn(c net.Conn) {
	conn := s.newClientConn(c) //新建一個conn

	defer func() {
		err := recover()
		if err != nil {
			const size = 4096
			buf := make([]byte, size)
			buf = buf[:runtime.Stack(buf, false)] //獲得當前goroutine的stacktrace
			golog.Error("server", "onConn", "error", 0,
				"remoteAddr", c.RemoteAddr().String(),
				"stack", string(buf),
			)
		}

		conn.Close()
	}()

	if allowConnect := conn.IsAllowConnect(); allowConnect == false {
		err := mysql.NewError(mysql.ER_ACCESS_DENIED_ERROR, "ip address access denied by kingshard.")
		conn.writeError(err)
		conn.Close()
		return
	}
	if err := conn.Handshake(); err != nil {
		golog.Error("server", "onConn", err.Error(), 0)
		c.Close()
		return
	}

	conn.Run()
}

//返回true表示已經處理，false表示未處理
func (c *ClientConn) preHandleShard(sql string) (bool, error) {
	var rs []*mysql.Result
	var err error

	var execNode *backend.Node
	var fromSlave bool = false

	if len(sql) == 0 {
		return false, errors.ErrCmdUnsupport
	}

	tokens := strings.Fields(sql)
	if len(tokens) == 0 {
		return false, errors.ErrCmdUnsupport
	}

	if c.needBeginTx() {
		execNode, err = c.GetTransExecNode(tokens, sql)
	} else {
		execNode, fromSlave, err = c.GetExecNode(tokens, sql)
	}

	if err != nil {
		return false, err
	}
	//need shard sql
	if execNode == nil {
		return false, nil
	}

	//execute in Master DB
	conn, err := c.getBackendConn(execNode, fromSlave)
	if err != nil {
		return false, err
	}
	rs, err = c.executeInNode(conn, sql, nil)
	if err != nil {
		return false, err
	}
	c.closeConn(conn, false)

	if len(rs) == 0 {
		msg := fmt.Sprintf("result is empty")
		golog.Error("ClientConn", "handleUnsupport", msg, c.connectionId)
		return false, mysql.NewError(mysql.ER_UNKNOWN_ERROR, msg)
	}

	if rs[0].Resultset != nil {
		err = c.writeResultset(c.status, rs[0].Resultset)
	} else {
		err = c.writeOK(rs[0])
	}
	if err != nil {
		return false, err
	}

	return true, nil
}

//preprocessing sql before parse sql
func (c *ClientConn) preHandleShard(sql string) (bool, error) {
	var rs []*mysql.Result
	var err error
	var executeDB *ExecuteDB

	if len(sql) == 0 {
		return false, errors.ErrCmdUnsupport
	}

	tokens := strings.Fields(sql)
	if len(tokens) == 0 {
		return false, errors.ErrCmdUnsupport
	}

	if c.isInTransaction() {
		executeDB, err = c.GetTransExecDB(tokens, sql)
	} else {
		executeDB, err = c.GetExecDB(tokens, sql)
	}

	if err != nil {
		return false, err
	}
	//need shard sql
	if executeDB == nil {
		return false, nil
	}
	//get connection in DB
	conn, err := c.getBackendConn(executeDB.ExecNode, executeDB.IsSlave)
	defer c.closeConn(conn, false)
	if err != nil {
		return false, err
	}
	rs, err = c.executeInNode(conn, sql, nil)
	if err != nil {
		return false, err
	}

	if len(rs) == 0 {
		msg := fmt.Sprintf("result is empty")
		golog.Error("ClientConn", "handleUnsupport", msg, 0, "sql", sql)
		return false, mysql.NewError(mysql.ER_UNKNOWN_ERROR, msg)
	}

	if rs[0].Resultset != nil {
		err = c.writeResultset(c.status, rs[0].Resultset)
	} else {
		err = c.writeOK(rs[0])
	}

	if err != nil {
		return false, err
	}

	return true, nil
}

func (c *ClientConn) dispatch(data []byte) error {
	c.proxy.counter.IncrClientQPS()
	cmd := data[0]
	data = data[1:]

	switch cmd {
	case mysql.COM_QUIT:
		c.Close()
		return nil
	case mysql.COM_QUERY:
		return c.handleQuery(hack.String(data))
	case mysql.COM_PING:
		return c.writeOK(nil)
	case mysql.COM_INIT_DB:
		if err := c.useDB(hack.String(data)); err != nil {
			return err
		} else {
			return c.writeOK(nil)
		}
	case mysql.COM_FIELD_LIST:
		return c.handleFieldList(data)
	case mysql.COM_STMT_PREPARE:
		return c.handleStmtPrepare(hack.String(data))
	case mysql.COM_STMT_EXECUTE:
		return c.handleStmtExecute(data)
	case mysql.COM_STMT_CLOSE:
		return c.handleStmtClose(data)
	case mysql.COM_STMT_SEND_LONG_DATA:
		return c.handleStmtSendLongData(data)
	case mysql.COM_STMT_RESET:
		return c.handleStmtReset(data)
	case mysql.COM_SET_OPTION:
		return c.writeEOF(0)
	default:
		msg := fmt.Sprintf("command %d not supported now", cmd)
		golog.Error("ClientConn", "dispatch", msg, 0)
		return mysql.NewError(mysql.ER_UNKNOWN_ERROR, msg)
	}

	return nil
}

func (c *ClientConn) writeError(e error) error {
	var m *mysql.SqlError
	var ok bool
	if m, ok = e.(*mysql.SqlError); !ok {
		m = mysql.NewError(mysql.ER_UNKNOWN_ERROR, e.Error())
	}

	data := make([]byte, 4, 16+len(m.Message))

	data = append(data, mysql.ERR_HEADER)
	data = append(data, byte(m.Code), byte(m.Code>>8))

	if c.capability&mysql.CLIENT_PROTOCOL_41 > 0 {
		data = append(data, '#')
		data = append(data, m.State...)
	}

	data = append(data, m.Message...)

	return c.writePacket(data)
}

//preprocessing sql before parse sql
func (c *ClientConn) preHandleShard(sql string) (bool, error) {
	var rs []*mysql.Result
	var err error
	var executeDB *ExecuteDB

	if len(sql) == 0 {
		return false, errors.ErrCmdUnsupport
	}
	//filter the blacklist sql
	if c.proxy.blacklistSqls[c.proxy.blacklistSqlsIndex].sqlsLen != 0 {
		if c.isBlacklistSql(sql) {
			golog.OutputSql("Forbidden", "%s->%s:%s",
				c.c.RemoteAddr(),
				c.proxy.addr,
				sql,
			)
			err := mysql.NewError(mysql.ER_UNKNOWN_ERROR, "sql in blacklist.")
			return false, err
		}
	}

	tokens := strings.FieldsFunc(sql, hack.IsSqlSep)

	if len(tokens) == 0 {
		return false, errors.ErrCmdUnsupport
	}

	if c.isInTransaction() {
		executeDB, err = c.GetTransExecDB(tokens, sql)
	} else {
		executeDB, err = c.GetExecDB(tokens, sql)
	}

	if err != nil {
		//this SQL doesn't need execute in the backend.
		if err == errors.ErrIgnoreSQL {
			err = c.writeOK(nil)
			if err != nil {
				return false, err
			}
			return true, nil
		}
		return false, err
	}
	//need shard sql
	if executeDB == nil {
		return false, nil
	}
	//get connection in DB
	conn, err := c.getBackendConn(executeDB.ExecNode, executeDB.IsSlave)
	defer c.closeConn(conn, false)
	if err != nil {
		return false, err
	}
	rs, err = c.executeInNode(conn, sql, nil)
	if err != nil {
		return false, err
	}

	if len(rs) == 0 {
		msg := fmt.Sprintf("result is empty")
		golog.Error("ClientConn", "handleUnsupport", msg, 0, "sql", sql)
		return false, mysql.NewError(mysql.ER_UNKNOWN_ERROR, msg)
	}

	c.lastInsertId = int64(rs[0].InsertId)
	c.affectedRows = int64(rs[0].AffectedRows)

	if rs[0].Resultset != nil {
		err = c.writeResultset(c.status, rs[0].Resultset)
	} else {
		err = c.writeOK(rs[0])
	}

	if err != nil {
		return false, err
	}

	return true, nil
}

func (c *ClientConn) handleStmtExecute(data []byte) error {
	if len(data) < 9 {
		return mysql.ErrMalformPacket
	}

	pos := 0
	id := binary.LittleEndian.Uint32(data[0:4])
	pos += 4

	s, ok := c.stmts[id]
	if !ok {
		return mysql.NewDefaultError(mysql.ER_UNKNOWN_STMT_HANDLER,
			strconv.FormatUint(uint64(id), 10), "stmt_execute")
	}

	flag := data[pos]
	pos++
	//now we only support CURSOR_TYPE_NO_CURSOR flag
	if flag != 0 {
		return mysql.NewError(mysql.ER_UNKNOWN_ERROR, fmt.Sprintf("unsupported flag %d", flag))
	}

	//skip iteration-count, always 1
	pos += 4

	var nullBitmaps []byte
	var paramTypes []byte
	var paramValues []byte

	paramNum := s.params

	if paramNum > 0 {
		nullBitmapLen := (s.params + 7) >> 3
		if len(data) < (pos + nullBitmapLen + 1) {
			return mysql.ErrMalformPacket
		}
		nullBitmaps = data[pos : pos+nullBitmapLen]
		pos += nullBitmapLen

		//new param bound flag
		if data[pos] == 1 {
			pos++
			if len(data) < (pos + (paramNum << 1)) {
				return mysql.ErrMalformPacket
			}

			paramTypes = data[pos : pos+(paramNum<<1)]
			pos += (paramNum << 1)

			paramValues = data[pos:]
		}

		if err := c.bindStmtArgs(s, nullBitmaps, paramTypes, paramValues); err != nil {
			return err
		}
	}

	var err error

	switch stmt := s.s.(type) {
	case *sqlparser.Select:
		err = c.handlePrepareSelect(stmt, s.sql, s.args)
	case *sqlparser.Insert:
		err = c.handlePrepareExec(s.s, s.sql, s.args)
	case *sqlparser.Update:
		err = c.handlePrepareExec(s.s, s.sql, s.args)
	case *sqlparser.Delete:
		err = c.handlePrepareExec(s.s, s.sql, s.args)
	case *sqlparser.Replace:
		err = c.handlePrepareExec(s.s, s.sql, s.args)
	default:
		err = fmt.Errorf("command %T not supported now", stmt)
	}

	s.ResetParams()

	return err
}