perf: improve get goroutine id

[rfyiamcool]

change

import goroutineID() performance.

test code

package async

import (
	"bytes"
	"fmt"
	"runtime"
	"runtime/debug"
	"strconv"
	"testing"

	"github.com/reugn/async/internal"
)

func TestGoroutineID(t *testing.T) {
	gid, err := goroutineID()
	internal.AssertEqual(t, nil, err)

	ggid, err := goroutineID2()
	internal.AssertEqual(t, nil, err)

	internal.AssertEqual(t, gid, ggid)
}

func BenchmarkGetGroutineID(b *testing.B) {
	for i := 0; i < b.N; i++ {
		_, err := goroutineID()
		if err != nil {
			b.Error("failed to get gid")
		}
	}
}

func BenchmarkGetGroutineID2(b *testing.B) {
	for i := 0; i < b.N; i++ {
		_, err := goroutineID2()
		if err != nil {
			b.Error("failed to get gid")
		}
	}
}

func goroutineID() (uint, error) {
	var id uint
	var prefix string
	_, err := fmt.Sscanf(string(debug.Stack()), "%s %d", &prefix, &id)
	if err != nil {
		return 0, err
	}
	return id, nil
}

func goroutineID2() (uint64, error) {
	b := make([]byte, 64)
	b = b[:runtime.Stack(b, false)]
	b = bytes.TrimPrefix(b, []byte("goroutine "))
	b = b[:bytes.IndexByte(b, ' ')]
	n, err := strconv.ParseUint(string(b), 10, 64)
	return n, err
}

test pass

=== RUN   TestGoroutineID
--- PASS: TestGoroutineID (0.00s)

benchmark result

BenchmarkGetGroutineID
BenchmarkGetGroutineID-12     	  261309	      4575 ns/op	    1712 B/op	       8 allocs/op
BenchmarkGetGroutineID2
BenchmarkGetGroutineID2-12    	  383796	      2994 ns/op	      66 B/op	       2 allocs/op

[codecov-commenter]

Codecov Report

Merging #10 (033d463) into master (4511bba) will increase coverage by 0.87%.
The diff coverage is 100.00%.

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@@            Coverage Diff             @@
##           master      #10      +/-   ##
==========================================
+ Coverage   85.15%   86.02%   +0.87%     
==========================================
  Files           8        8              
  Lines         229      229              
==========================================
+ Hits          195      197       +2     
+ Misses         19       18       -1     
+ Partials       15       14       -1     

Files Changed	Coverage Δ
goroutine.go	100.00% <100.00%> (+28.57%)	⬆️

[reugn]

Thanks, @rfyiamcool.