optimize: select db version once in one connection (#554)

* perf: optimize the performance of XA transactions

pkg/datasource/sql/connector.go

@@ -20,14 +20,11 @@ package sql
 import (
 	"context"
 	"database/sql/driver"
-	"errors"
-	"github.com/go-sql-driver/mysql"
-	"io"
-	"reflect"
 	"sync"
 
+	"github.com/go-sql-driver/mysql"
+
 	"github.com/seata/seata-go/pkg/datasource/sql/types"
-	"github.com/seata/seata-go/pkg/util/log"
 )
 
 type seataATConnector struct {
@@ -117,16 +114,6 @@ func (c *seataConnector) Connect(ctx context.Context) (driver.Conn, error) {
 	if err != nil {
 		return nil, err
 	}
-
-	// get the version of mysql for xa.
-	if c.transType == types.XAMode {
-		version, err := c.dbVersion(ctx, conn)
-		if err != nil {
-			return nil, err
-		}
-		c.res.SetDbVersion(version)
-	}
-
 	return &Conn{
 		targetConn: conn,
 		res:        c.res,
@@ -137,44 +124,6 @@ func (c *seataConnector) Connect(ctx context.Context) (driver.Conn, error) {
 	}, nil
 }
 
-func (c *seataConnector) dbVersion(ctx context.Context, conn driver.Conn) (string, error) {
-	queryConn, isQueryContext := conn.(driver.QueryerContext)
-	if !isQueryContext {
-		return "", errors.New("get db version error for unexpected driver conn")
-	}
-
-	res, err := queryConn.QueryContext(ctx, "SELECT VERSION()", nil)
-	if err != nil {
-		log.Errorf("seata connector get the xa mysql version err:%v", err)
-		return "", err
-	}
-
-	dest := make([]driver.Value, 1)
-	var version string
-
-	if err = res.Next(dest); err != nil {
-		if err == io.EOF {
-			return version, nil
-		}
-		return "", err
-	}
-	if len(dest) != 1 {
-		return "", errors.New("get the mysql version is not column 1")
-	}
-
-	switch reflect.TypeOf(dest[0]).Kind() {
-	case reflect.Slice, reflect.Array:
-		val := reflect.ValueOf(dest[0]).Bytes()
-		version = string(val)
-	case reflect.String:
-		version = reflect.ValueOf(dest[0]).String()
-	default:
-		return "", errors.New("get the mysql version is not a string")
-	}
-
-	return version, nil
-}
-
 // Driver returns the underlying Driver of the Connector,
 // mainly to maintain compatibility with the Driver method
 // on sql.DB.

pkg/datasource/sql/db.go

@@ -29,6 +29,7 @@ import (
 	"github.com/seata/seata-go/pkg/datasource/sql/undo"
 	"github.com/seata/seata-go/pkg/datasource/sql/util"
 	"github.com/seata/seata-go/pkg/protocol/branch"
+	"github.com/seata/seata-go/pkg/util/log"
 )
 
 type dbOption func(db *DBResource)
@@ -123,6 +124,16 @@ func (db *DBResource) GetResourceGroupId() string {
 }
 
 func (db *DBResource) init() {
+	ctx := context.Background()
+	conn, err := db.connector.Connect(ctx)
+	if err != nil {
+		log.Errorf("connect: %w", err)
+	}
+	version, err := selectDBVersion(ctx, conn)
+	if err != nil {
+		log.Errorf("select db version: %w", err)
+	}
+	db.SetDbVersion(version)
 	db.checkDbVersion()
 }
 

pkg/datasource/sql/driver.go

@@ -23,13 +23,15 @@ import (
 	"database/sql/driver"
 	"errors"
 	"fmt"
+	"io"
+	"reflect"
 	"strings"
 
 	"github.com/go-sql-driver/mysql"
-
 	"github.com/seata/seata-go/pkg/datasource/sql/datasource"
 	mysql2 "github.com/seata/seata-go/pkg/datasource/sql/datasource/mysql"
 	"github.com/seata/seata-go/pkg/datasource/sql/types"
+	"github.com/seata/seata-go/pkg/datasource/sql/util"
 	"github.com/seata/seata-go/pkg/protocol/branch"
 	"github.com/seata/seata-go/pkg/util/log"
 )
@@ -147,20 +149,16 @@ func (d *seataDriver) getOpenConnectorProxy(connector driver.Connector, dbType t
 		withDBName(cfg.DBName),
 		withConnector(connector),
 	}
-
 	res, err := newResource(options...)
 	if err != nil {
 		log.Errorf("create new resource: %w", err)
 		return nil, err
 	}
-
 	datasource.RegisterTableCache(types.DBTypeMySQL, mysql2.NewTableMetaInstance(db))
-
 	if err = datasource.GetDataSourceManager(d.branchType).RegisterResource(res); err != nil {
 		log.Errorf("regisiter resource: %w", err)
 		return nil, err
 	}
-
 	return &seataConnector{
 		res:    res,
 		target: connector,
@@ -193,3 +191,53 @@ func parseResourceID(dsn string) string {
 	}
 	return strings.ReplaceAll(res, ",", "|")
 }
+
+func selectDBVersion(ctx context.Context, conn driver.Conn) (string, error) {
+	var rowsi driver.Rows
+	var err error
+
+	queryerCtx, ok := conn.(driver.QueryerContext)
+	var queryer driver.Queryer
+	if !ok {
+		queryer, ok = conn.(driver.Queryer)
+	}
+	if ok {
+		rowsi, err = util.CtxDriverQuery(ctx, queryerCtx, queryer, "SELECT VERSION()", nil)
+		defer func() {
+			if rowsi != nil {
+				rowsi.Close()
+			}
+		}()
+		if err != nil {
+			log.Errorf("ctx driver query: %+v", err)
+			return "", err
+		}
+	} else {
+		log.Errorf("target conn should been driver.QueryerContext or driver.Queryer")
+		return "", fmt.Errorf("invalid conn")
+	}
+
+	dest := make([]driver.Value, 1)
+	var version string
+	if err = rowsi.Next(dest); err != nil {
+		if err == io.EOF {
+			return version, nil
+		}
+		return "", err
+	}
+	if len(dest) != 1 {
+		return "", errors.New("get db version is not column 1")
+	}
+
+	switch reflect.TypeOf(dest[0]).Kind() {
+	case reflect.Slice, reflect.Array:
+		val := reflect.ValueOf(dest[0]).Bytes()
+		version = string(val)
+	case reflect.String:
+		version = reflect.ValueOf(dest[0]).String()
+	default:
+		return "", errors.New("get db version is not a string")
+	}
+
+	return version, nil
+}

pkg/rm/tcc/fence/fence_driver_tx.go

@@ -1,3 +1,20 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package fence
 
 import (

pkg/rm/tcc/fence/fennce_driver_test.go

@@ -1,3 +1,20 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package fence
 
 import (