func (s *Server) onConn(c net.Conn) {
conn := s.newClientConn(c) //新建一个conn
defer func() {
err := recover()
if err != nil {
const size = 4096
buf := make([]byte, size)
buf = buf[:runtime.Stack(buf, false)] //获得当前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表示已经处理，false表示未处理
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.isInTransaction() {
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
}
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)
}
func (c *ClientConn) dispatch(data []byte) error {
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)
default:
msg := fmt.Sprintf("command %d not supported now", cmd)
return mysql.NewError(mysql.ER_UNKNOWN_ERROR, msg)
}
return 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
}