Golang mysql.NewErrf函數代碼示例

func (cc *clientConn) writeError(e error) error {
	var (
		m  *mysql.SQLError
		te *terror.Error
		ok bool
	)
	originErr := errors.Cause(e)
	if te, ok = originErr.(*terror.Error); ok {
		m = te.ToSQLError()
	} else {
		m = mysql.NewErrf(mysql.ErrUnknown, e.Error())
	}

	data := cc.alloc.AllocWithLen(4, 16+len(m.Message))
	data = append(data, mysql.ErrHeader)
	data = append(data, byte(m.Code), byte(m.Code>>8))
	if cc.capability&mysql.ClientProtocol41 > 0 {
		data = append(data, '#')
		data = append(data, m.State...)
	}

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

	err := cc.writePacket(data)
	if err != nil {
		return errors.Trace(err)
	}
	return errors.Trace(cc.flush())
}

// dispatch handles client request based on command which is the first byte of the data.
// It also gets a token from server which is used to limit the concurrently handling clients.
// The most frequently used command is ComQuery.
func (cc *clientConn) dispatch(data []byte) error {
	cmd := data[0]
	data = data[1:]
	cc.lastCmd = hack.String(data)

	token := cc.server.getToken()

	startTS := time.Now()
	defer func() {
		cc.server.releaseToken(token)
		log.Debugf("[TIME_CMD] %v %d", time.Since(startTS), cmd)
	}()

	switch cmd {
	case mysql.ComSleep:
		// TODO: According to mysql document, this command is supposed to be used only internally.
		// So it's just a temp fix, not sure if it's done right.
		// Investigate this command and write test case later.
		return nil
	case mysql.ComQuit:
		return io.EOF
	case mysql.ComQuery: // Most frequently used command.
		// For issue 1989
		// Input payload may end with byte '\0', we didn't find related mysql document about it, but mysql
		// implementation accept that case. So trim the last '\0' here as if the payload an EOF string.
		// See http://dev.mysql.com/doc/internals/en/com-query.html
		if data[len(data)-1] == 0 {
			data = data[:len(data)-1]
		}
		return cc.handleQuery(hack.String(data))
	case mysql.ComPing:
		return cc.writeOK()
	case mysql.ComInitDB:
		log.Debug("init db", hack.String(data))
		if err := cc.useDB(hack.String(data)); err != nil {
			return errors.Trace(err)
		}
		return cc.writeOK()
	case mysql.ComFieldList:
		return cc.handleFieldList(hack.String(data))
	case mysql.ComStmtPrepare:
		return cc.handleStmtPrepare(hack.String(data))
	case mysql.ComStmtExecute:
		return cc.handleStmtExecute(data)
	case mysql.ComStmtClose:
		return cc.handleStmtClose(data)
	case mysql.ComStmtSendLongData:
		return cc.handleStmtSendLongData(data)
	case mysql.ComStmtReset:
		return cc.handleStmtReset(data)
	case mysql.ComSetOption:
		return cc.handleSetOption(data)
	default:
		return mysql.NewErrf(mysql.ErrUnknown, "command %d not supported now", cmd)
	}
}

// dispatch handles client request based on command which is the first byte of the data.
// It also gets a token from server which is used to limit the concurrently handling clients.
// The most frequently used command is ComQuery.
func (cc *clientConn) dispatch(data []byte) error {
	cmd := data[0]
	data = data[1:]
	cc.lastCmd = hack.String(data)

	token := cc.server.getToken()

	startTS := time.Now()
	defer func() {
		cc.server.releaseToken(token)
		log.Debugf("[TIME_CMD] %v %d", time.Since(startTS), cmd)
	}()

	switch cmd {
	case mysql.ComSleep:
		// TODO: According to mysql document, this command is supposed to be used only internally.
		// So it's just a temp fix, not sure if it's done right.
		// Investigate this command and write test case later.
		return nil
	case mysql.ComQuit:
		return io.EOF
	case mysql.ComQuery: // Most frequently used command.
		return cc.handleQuery(hack.String(data))
	case mysql.ComPing:
		return cc.writeOK()
	case mysql.ComInitDB:
		log.Debug("init db", hack.String(data))
		if err := cc.useDB(hack.String(data)); err != nil {
			return errors.Trace(err)
		}
		return cc.writeOK()
	case mysql.ComFieldList:
		return cc.handleFieldList(hack.String(data))
	case mysql.ComStmtPrepare:
		return cc.handleStmtPrepare(hack.String(data))
	case mysql.ComStmtExecute:
		return cc.handleStmtExecute(data)
	case mysql.ComStmtClose:
		return cc.handleStmtClose(data)
	case mysql.ComStmtSendLongData:
		return cc.handleStmtSendLongData(data)
	case mysql.ComStmtReset:
		return cc.handleStmtReset(data)
	case mysql.ComSetOption:
		return cc.handleSetOption(data)
	default:
		return mysql.NewErrf(mysql.ErrUnknown, "command %d not supported now", cmd)
	}
}

func (cc *clientConn) dispatch(data []byte) error {
	cmd := data[0]
	data = data[1:]
	cc.lastCmd = hack.String(data)

	token := cc.server.getToken()

	defer func() {
		cc.server.releaseToken(token)
	}()

	switch cmd {
	case mysql.ComQuit:
		return io.EOF
	case mysql.ComQuery:
		return cc.handleQuery(hack.String(data))
	case mysql.ComPing:
		return cc.writeOK()
	case mysql.ComInitDB:
		log.Debug("init db", hack.String(data))
		if err := cc.useDB(hack.String(data)); err != nil {
			return errors.Trace(err)
		}
		return cc.writeOK()
	case mysql.ComFieldList:
		return cc.handleFieldList(hack.String(data))
	case mysql.ComStmtPrepare:
		return cc.handleStmtPrepare(hack.String(data))
	case mysql.ComStmtExecute:
		return cc.handleStmtExecute(data)
	case mysql.ComStmtClose:
		return cc.handleStmtClose(data)
	case mysql.ComStmtSendLongData:
		return cc.handleStmtSendLongData(data)
	case mysql.ComStmtReset:
		return cc.handleStmtReset(data)
	default:
		return mysql.NewErrf(mysql.ErrUnknown, "command %d not supported now", cmd)
	}
}

func (cc *clientConn) writeError(e error) error {
	var m *mysql.SQLError
	var ok bool
	originErr := errors.Cause(e)
	if m, ok = originErr.(*mysql.SQLError); !ok {
		m = mysql.NewErrf(mysql.ErrUnknown, e.Error())
	}

	data := make([]byte, 4, 16+len(m.Message))
	data = append(data, mysql.ErrHeader)
	data = append(data, byte(m.Code), byte(m.Code>>8))
	if cc.capability&mysql.ClientProtocol41 > 0 {
		data = append(data, '#')
		data = append(data, m.State...)
	}

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

	err := cc.writePacket(data)
	if err != nil {
		return errors.Trace(err)
	}
	return errors.Trace(cc.flush())
}

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

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

	stmt := cc.ctx.GetStatement(int(stmtID))
	if stmt == nil {
		return mysql.NewErr(mysql.ErrUnknownStmtHandler,
			strconv.FormatUint(uint64(stmtID), 10), "stmt_execute")
	}

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

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

	var (
		nullBitmaps []byte
		paramTypes  []byte
		paramValues []byte
	)
	numParams := stmt.NumParams()
	args := make([]interface{}, numParams)
	if numParams > 0 {
		nullBitmapLen := (numParams + 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 + (numParams << 1)) {
				return mysql.ErrMalformPacket
			}

			paramTypes = data[pos : pos+(numParams<<1)]
			pos += (numParams << 1)
			paramValues = data[pos:]
		}

		err = parseStmtArgs(args, stmt.BoundParams(), nullBitmaps, paramTypes, paramValues)
		if err != nil {
			return errors.Trace(err)
		}
	}
	rs, err := stmt.Execute(args...)
	if err != nil {
		return errors.Trace(err)
	}
	if rs == nil {
		return errors.Trace(cc.writeOK())
	}

	return errors.Trace(cc.writeResultset(rs, true))
}

// ToSQLError convert Error to mysql.SQLError.
func (e *Error) ToSQLError() *mysql.SQLError {
	code := e.getMySQLErrorCode()
	return mysql.NewErrf(code, e.getMsg())
}