[Question] How can I stream the results? #1054
Description
In my code:
package main
import (
"log"
"net"
"time"
"github.com/go-mysql-org/go-mysql/mysql"
"github.com/go-mysql-org/go-mysql/server"
)
type MySQLStreamResultTestHandler struct {
clientAddr string
*server.Conn
}
func (h *MySQLStreamResultTestHandler) UseDB(dbName string) error {
return nil
}
func (h *MySQLStreamResultTestHandler) HandleQuery(query string) (*mysql.Result, error) {
log.Printf("Received query: %s from %s", query, h.clientAddr)
if query == "show binary logs" {
names := []string{"Log_name", "File_size"}
values := [][]any{{"mysql-bin.001000", "123"}}
r1, _ := mysql.BuildSimpleResultset(names, values, false)
// r1.Streaming = mys
r1.StreamingDone = false
r1.Streaming = mysql.StreamingSelect
r1result := mysql.NewResult(r1)
h.WriteValue(r1result)
r2, _ := mysql.BuildSimpleResultset(names, values, false)
r2.Streaming = mysql.StreamingNone
r2.StreamingDone = true
r2result := mysql.NewResult(r2)
// h.WriteValue(r2result)
return r2result, nil
}
return nil, nil
}
func (h *MySQLStreamResultTestHandler) HandleFieldList(table string, fieldWildcard string) ([]*mysql.Field, error) {
return nil, nil
}
func (h *MySQLStreamResultTestHandler) HandleStmtPrepare(query string) (params int, columns int, context interface{}, err error) {
return 0, 0, nil, nil
}
func (h *MySQLStreamResultTestHandler) HandleStmtExecute(context interface{}, query string, args []interface{}) (*mysql.Result, error) {
return nil, nil
}
func (h *MySQLStreamResultTestHandler) HandleStmtClose(context interface{}) error {
return nil
}
func (h *MySQLStreamResultTestHandler) HandleOtherCommand(cmd byte, data []byte) error {
return nil
}
func main() {
listener, err := net.Listen("tcp", "127.0.0.1:4000")
if err != nil {
log.Fatalf("Failed to listen on TCP address: %v", err)
}
go func() {
for {
conn, err := listener.Accept()
if err != nil {
log.Fatalf("Failed to accept TCP connection: %v", err)
return
}
cmdHandler := &MySQLStreamResultTestHandler{
clientAddr: conn.RemoteAddr().String(),
}
mysqlConn, err := server.NewConn(conn, "root", "", cmdHandler)
if err != nil {
log.Fatalf("Failed to create MySQL connection: %v", err)
return
}
for {
if err := mysqlConn.HandleCommand(); err != nil {
log.Fatal(err)
}
}
}
}()
time.Sleep(1000 * time.Second)
}This example will panic!
Some queries have too much data and I need to stream the Result to reduce the server-side memory footprint.
But I have a question about the use of *mysql.Result, can you provide an example that shows me how to query with Stream Result?