Allow disabling of stack traces

[tebeka]

Adding of stack traces have performance penalty. In #123 I show a little benchmark on performance with or without stack traces. Repeating it here below.

I know that usually errors are not in the critical path of performance, but sometime they do and I'm working on very performance oriented project right now, every ns counts :)

err_test.go

package main

import (
	"fmt"
	"testing"

	"github.com/pkg/errors"
)

var err1 = errors.New("hi")

func pkgError(err error, i int) error {
	return errors.Wrapf(err, "error number %d", i)
}

func fmtError(err error, i int) error {
	return fmt.Errorf("error number %d (%s)", i, err)
}

func BenchmarkPkg(b *testing.B) {
	for i := 0; i < b.N; i++ {
		pkgError(err1, i)
	}
}

func BenchmarkFmt(b *testing.B) {
	for i := 0; i < b.N; i++ {
		fmtError(err1, i)
	}
}

func BenchmarkPkgNoStack(b *testing.B) {
	errors.AddStack(false)
	defer errors.AddStack(true)
	for i := 0; i < b.N; i++ {
		pkgError(err1, i)
	}
}

Results

$ go test -bench . /tmp/err_test.go 
BenchmarkPkg-4          	 1000000	      1090 ns/op
BenchmarkFmt-4          	 5000000	       323 ns/op
BenchmarkPkgNoStack-4   	10000000	       212 ns/op
PASS
ok  	command-line-arguments	5.386s

[davecheney]

I want to be clear about this, especially after telling you to raise an issue. Basically if you had raised the issue first I would have told you not to write this code. Sorry for wasting your time. I'm sorry but I don't want to add this feature. Stack traces are the reason this package exists, if they are disabled there is no reason to use this package.

…

On Wed, Jul 5, 2017 at 4:04 PM, Miki Tebeka ***@***.***> wrote: Adding of stack traces have performance penalty. In #123 <#123> I show a little benchmark on performance with or without stack traces. Repeating it here below. I know that usually errors are not in the critical path of performance, but sometime they do and I'm working on very performance oriented project right now, every ns counts :) err_test.go package main import ( "fmt" "testing" "github.com/pkg/errors" ) var err1 = errors.New("hi") func pkgError(err error, i int) error { return errors.Wrapf(err, "error number %d", i) } func fmtError(err error, i int) error { return fmt.Errorf("error number %d (%s)", i, err) } func BenchmarkPkg(b *testing.B) { for i := 0; i < b.N; i++ { pkgError(err1, i) } } func BenchmarkFmt(b *testing.B) { for i := 0; i < b.N; i++ { fmtError(err1, i) } } func BenchmarkPkgNoStack(b *testing.B) { errors.AddStack(false) defer errors.AddStack(true) for i := 0; i < b.N; i++ { pkgError(err1, i) } } Results $ go test -bench . /tmp/err_test.go BenchmarkPkg-4 1000000 1090 ns/op BenchmarkFmt-4 5000000 323 ns/op BenchmarkPkgNoStack-4 10000000 212 ns/op PASS ok command-line-arguments 5.386s — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#124>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAcAyLtHIIOEsYBVec6OJ_C4-bTbj1uks5sKyeAgaJpZM4ON5Ex> .

[tebeka]

No worries, just an idea. Thanks for considering this.

BTW: I don't think stack traces are the only reason for this. The chaining of errors is highly value by itself.

[davecheney]

If you don't want an error with a stack trace, use the stdlib fmt or errors package. If you want to wrap an error without collecting a stack, use WithMessage.

[tebeka]

So I guess I'm just missing WithMessagef :)