Faster utils.FileWithLineNum

[kkocdko]

• Do only one thing
• Non breaking API changes
• Tested (may be untestable for ci)

What did this pull request do?

Faster utils.FileWithLineNum. Avoid call runtime.Caller multi times.

Trace log performace gained a little.

[kkocdko]

Called here https://github.com/go-gorm/gorm/blob/v1.25.9/logger/logger.go#L180

Bench code:

package main

import (
	"context"
	"fmt"
	"strings"
	"time"

	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
	"gorm.io/gorm/utils"
)

type dlog struct{}

func (dlog) LogMode(logger.LogLevel) logger.Interface { return dlog{} }
func (dlog) Info(context.Context, string, ...any)     {}
func (dlog) Warn(context.Context, string, ...any)     {}
func (dlog) Error(context.Context, string, ...any)    {}
func (dlog) Trace(_ context.Context, begin time.Time, fc func() (sql string, rowsAffected int64), err error) {
	if strings.HasSuffix(utils.FileWithLineNum(), "main.go:34") {
		panic("not same")
	}
}

func main() {
	db, _ := gorm.Open(mysql.Open("root@tcp(127.0.0.1:3306)"), &gorm.Config{Logger: dlog{}})
	db.Exec("select 1")
	for j := 0; j < 10; j++ {
		benchBegin := time.Now()
		for i := 0; i < 9000; i++ {
			db.Exec("select 1")
		}
		fmt.Printf("bench: %v\n", time.Since(benchBegin).Nanoseconds())
	}
}

Before

bench: 49571265
bench: 48794627
bench: 48044889
bench: 48055469
bench: 47996819
bench: 48150127
bench: 49503758
bench: 55815334
bench: 50576992
bench: 48269490
[kkocdko@klf higoweb]$ 

After

bench: 36544193
bench: 37921297
bench: 35384326
bench: 36247647
bench: 35748119
bench: 35659121
bench: 35108277
bench: 35288646
bench: 35050349
bench: 35066890
[kkocdko@klf higoweb]$

On a long chain call, like db.Model(&User{}).Limit(10).Find(&APIUser{})..., the performance difference will be more significant.

[kkocdko]

Origin code 15-2=13. No breaking changes.

[kkocdko]

The runtime.Caller(i) 's inner is caller(skip+1), so we use runtime.Callers(3) in new implement.

[kkocdko]

The CI error is not my wrong, see #6982 , curious why?