split db specific op to a stand alone file

dtmcli/db_special.go

@@ -0,0 +1,70 @@
+package dtmcli
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// DBSpecial db specific operations
+type DBSpecial interface {
+	TimestampAdd(second int) string
+	GetPlaceHoldSQL(sql string) string
+	GetXaSQL(command string, xid string) string
+}
+
+type mysqlDBSpecial struct{}
+
+func (*mysqlDBSpecial) TimestampAdd(second int) string {
+	return fmt.Sprintf("date_add(now(), interval %d second)", second)
+}
+
+func (*mysqlDBSpecial) GetPlaceHoldSQL(sql string) string {
+	return sql
+}
+
+func (*mysqlDBSpecial) GetXaSQL(command string, xid string) string {
+	return fmt.Sprintf("xa %s '%s'", command, xid)
+}
+
+type postgresDBSpecial struct{}
+
+func (*postgresDBSpecial) TimestampAdd(second int) string {
+	return fmt.Sprintf("current_timestamp + interval '%d second'", second)
+}
+
+func (*postgresDBSpecial) GetXaSQL(command string, xid string) string {
+	return map[string]string{
+		"end":      "",
+		"start":    "begin",
+		"prepare":  fmt.Sprintf("prepare transaction '%s'", xid),
+		"commit":   fmt.Sprintf("commit prepared '%s'", xid),
+		"rollback": fmt.Sprintf("rollback prepared '%s'", xid),
+	}[command]
+}
+
+func (*postgresDBSpecial) GetPlaceHoldSQL(sql string) string {
+	pos := 1
+	parts := []string{}
+	b := 0
+	for i := 0; i < len(sql); i++ {
+		if sql[i] == '?' {
+			parts = append(parts, sql[b:i])
+			b = i + 1
+			parts = append(parts, fmt.Sprintf("$%d", pos))
+			pos++
+		}
+	}
+	parts = append(parts, sql[b:])
+	return strings.Join(parts, "")
+}
+
+// GetDBSpecial get DBSpecial for DBDriver
+func GetDBSpecial() DBSpecial {
+	if DBDriver == DriverMysql {
+		return &mysqlDBSpecial{}
+	} else if DBDriver == DriverPostgres {
+		return &postgresDBSpecial{}
+	}
+	panic(errors.New("unknown DBDriver, please set it to a valid driver: " + DBDriver))
+}

dtmcli/db_special_test.go

@@ -0,0 +1,27 @@
+package dtmcli
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDBSpecial(t *testing.T) {
+	old := DBDriver
+	DBDriver = "no-driver"
+	assert.Error(t, CatchP(func() {
+		GetDBSpecial()
+	}))
+	DBDriver = DriverMysql
+	sp := GetDBSpecial()
+
+	assert.Equal(t, "? ?", sp.GetPlaceHoldSQL("? ?"))
+	assert.Equal(t, "xa start 'xa1'", sp.GetXaSQL("start", "xa1"))
+	assert.Equal(t, "date_add(now(), interval 1000 second)", sp.TimestampAdd(1000))
+	DBDriver = DriverPostgres
+	sp = GetDBSpecial()
+	assert.Equal(t, "$1 $2", sp.GetPlaceHoldSQL("? ?"))
+	assert.Equal(t, "begin", sp.GetXaSQL("start", "xa1"))
+	assert.Equal(t, "current_timestamp + interval '1000 second'", sp.TimestampAdd(1000))
+	DBDriver = old
+}

dtmcli/utils.go

@@ -215,7 +215,7 @@ func DBExec(db DB, sql string, values ...interface{}) (affected int64, rerr erro
 	if sql == "" {
 		return 0, nil
 	}
-	sql = makeSQLCompatible(sql)
+	sql = GetDBSpecial().GetPlaceHoldSQL(sql)
 	r, rerr := db.Exec(sql, values...)
 	if rerr == nil {
 		affected, rerr = r.RowsAffected()
@@ -268,37 +268,3 @@ func CheckResult(res interface{}, err error) error {
 	}
 	return err
 }
-
-func makeSQLCompatible(sql string) string {
-	if DBDriver == DriverPostgres {
-		pos := 1
-		parts := []string{}
-		b := 0
-		for i := 0; i < len(sql); i++ {
-			if sql[i] == '?' {
-				parts = append(parts, sql[b:i])
-				b = i + 1
-				parts = append(parts, fmt.Sprintf("$%d", pos))
-				pos++
-			}
-		}
-		parts = append(parts, sql[b:])
-		return strings.Join(parts, "")
-	}
-	PanicIf(DBDriver != DriverMysql, fmt.Errorf("unkown db driver: %s", DBDriver))
-	return sql
-}
-
-func getXaSQL(action string, xid string) string {
-	if DBDriver == DriverPostgres {
-		return map[string]string{
-			"end":      "",
-			"start":    "begin",
-			"prepare":  fmt.Sprintf("prepare transaction '%s'", xid),
-			"commit":   fmt.Sprintf("commit prepared '%s'", xid),
-			"rollback": fmt.Sprintf("rollback prepared '%s'", xid),
-		}[action]
-	}
-	PanicIf(DBDriver != DriverMysql, fmt.Errorf("unkown db driver: %s", DBDriver))
-	return fmt.Sprintf("xa %s '%s'", action, xid)
-}

dtmcli/utils_test.go

@@ -89,14 +89,3 @@ func TestFatal(t *testing.T) {
 	})
 	assert.Error(t, err, fmt.Errorf("fatal"))
 }
-
-func TestCompatible(t *testing.T) {
-	old := DBDriver
-	DBDriver = DriverMysql
-	assert.Equal(t, "? ?", makeSQLCompatible("? ?"))
-	assert.Equal(t, "xa start 'xa1'", getXaSQL("start", "xa1"))
-	DBDriver = DriverPostgres
-	assert.Equal(t, "$1 $2", makeSQLCompatible("? ?"))
-	assert.Equal(t, "begin", getXaSQL("start", "xa1"))
-	DBDriver = old
-}

dtmcli/xa_base.go

@@ -20,7 +20,7 @@ func (xc *XaClientBase) HandleCallback(gid string, branchID string, action strin
 	}
 	defer db.Close()
 	xaID := gid + "-" + branchID
-	_, err = DBExec(db, getXaSQL(action, xaID))
+	_, err = DBExec(db, GetDBSpecial().GetXaSQL(action, xaID))
 	if err != nil &&
 		(strings.Contains(err.Error(), "Error 1397: XAER_NOTA") || strings.Contains(err.Error(), "does not exist")) { // 重复commit/rollback同一个id，报这个错误，忽略
 		err = nil
@@ -39,9 +39,9 @@ func (xc *XaClientBase) HandleLocalTrans(xa *TransBase, cb func(*sql.DB) (interf
 	defer func() { db.Close() }()
 	defer func() {
 		x := recover()
-		_, err := DBExec(db, getXaSQL("end", xaBranch))
+		_, err := DBExec(db, GetDBSpecial().GetXaSQL("end", xaBranch))
 		if x == nil && rerr == nil && err == nil {
-			_, err = DBExec(db, getXaSQL("prepare", xaBranch))
+			_, err = DBExec(db, GetDBSpecial().GetXaSQL("prepare", xaBranch))
 		}
 		if rerr == nil {
 			rerr = err
@@ -50,7 +50,7 @@ func (xc *XaClientBase) HandleLocalTrans(xa *TransBase, cb func(*sql.DB) (interf
 			panic(x)
 		}
 	}()
-	_, rerr = DBExec(db, getXaSQL("start", xaBranch))
+	_, rerr = DBExec(db, GetDBSpecial().GetXaSQL("start", xaBranch))
 	if rerr != nil {
 		return
 	}

dtmsvr/cron.go

@@ -41,12 +41,7 @@ func lockOneTrans(expireIn time.Duration) *TransGlobal {
 	trans := TransGlobal{}
 	owner := GenGid()
 	db := dbGet()
-	getTime := func(second int) string {
-		return fmt.Sprintf(map[string]string{
-			"mysql":    "date_add(now(), interval %d second)",
-			"postgres": "current_timestamp + interval '%d second'",
-		}[dtmcli.DBDriver], second)
-	}
+	getTime := dtmcli.GetDBSpecial().TimestampAdd
 	expire := int(expireIn / time.Second)
 	whereTime := fmt.Sprintf("next_cron_time < %s and next_cron_time > %s and update_time < %s", getTime(expire), getTime(-3600), getTime(expire-3))
 	// 这里next_cron_time需要限定范围，否则数据量累计之后，会导致查询变慢