opt: improve logx performance

[kevwan]

No description provided.

[codecov]

Codecov Report

Merging #3371 (3ef5707) into master (8d23ab1) will increase coverage by 0.02%.
The diff coverage is 100.00%.

Impacted Files	Coverage Δ
core/logx/logs.go	98.91% <100.00%> (+0.13%)	⬆️

... and 1 file with indirect coverage changes

[kevwan]

Benchmark code as below:

package main

import (
	"flag"
	"time"

	"github.com/kevwan/gobench"
	"github.com/zeromicro/go-zero/core/conf"
	"github.com/zeromicro/go-zero/core/logx"
)

const (
	config = `Name: bench
Mode: file
Level: error
Path: logs
`
	text = `The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too.`
)

var (
	duration = flag.Duration("duration", time.Minute, "duration")
	qps      = flag.Int("qps", 10000, "qps")
)

func main() {
	flag.Parse()

	var c logx.LogConf
	logx.Must(conf.LoadFromYamlBytes([]byte(config), &c))
	logx.MustSetup(c)

	for i := 0; i < 100; i++ {
		logx.Info(text)
	}

	b := gobench.NewBenchWithConfig(gobench.Config{
		Duration: *duration,
	})
	b.Run(*qps, func() {
		for i := 0; i < 100; i++ {
			logx.Info(text)
		}
		logx.Error(text)
	})
}

Before optimization:

After optimization:

[chenquan]

LGTM