distribution/registry/handlers/hooks.go
Sebastiaan van Stijn 3b391d3290
replace strings.Split(N) for strings.Cut() or alternatives
Go 1.18 and up now provides a strings.Cut() which is better suited for
splitting key/value pairs (and similar constructs), and performs better:

```go
func BenchmarkSplit(b *testing.B) {
	b.ReportAllocs()
	data := []string{"12hello=world", "12hello=", "12=hello", "12hello"}
	for i := 0; i < b.N; i++ {
		for _, s := range data {
			_ = strings.SplitN(s, "=", 2)[0]
		}
	}
}

func BenchmarkCut(b *testing.B) {
	b.ReportAllocs()
	data := []string{"12hello=world", "12hello=", "12=hello", "12hello"}
	for i := 0; i < b.N; i++ {
		for _, s := range data {
			_, _, _ = strings.Cut(s, "=")
		}
	}
}
```

    BenchmarkSplit
    BenchmarkSplit-10    	 8244206	       128.0 ns/op	     128 B/op	       4 allocs/op
    BenchmarkCut
    BenchmarkCut-10      	54411998	        21.80 ns/op	       0 B/op	       0 allocs/op

While looking at occurrences of `strings.Split()`, I also updated some for alternatives,
or added some constraints;

- for cases where an specific number of items is expected, I used `strings.SplitN()`
  with a suitable limit. This prevents (theoretical) unlimited splits.
- in some cases it we were using `strings.Split()`, but _actually_ were trying to match
  a prefix; for those I replaced the code to just match (and/or strip) the prefix.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2022-11-10 22:38:12 +01:00

52 lines
1.1 KiB
Go

package handlers
import (
"bytes"
"errors"
"fmt"
"strings"
"text/template"
"github.com/sirupsen/logrus"
)
// logHook is for hooking Panic in web application
type logHook struct {
LevelsParam []string
Mail *mailer
}
// Fire forwards an error to LogHook
func (hook *logHook) Fire(entry *logrus.Entry) error {
host, _, ok := strings.Cut(hook.Mail.Addr, ":")
if !ok || host == "" {
return errors.New("invalid Mail Address")
}
subject := fmt.Sprintf("[%s] %s: %s", entry.Level, host, entry.Message)
html := `
{{.Message}}
{{range $key, $value := .Data}}
{{$key}}: {{$value}}
{{end}}
`
b := bytes.NewBuffer(make([]byte, 0))
t := template.Must(template.New("mail body").Parse(html))
if err := t.Execute(b, entry); err != nil {
return err
}
body := b.String()
return hook.Mail.sendMail(subject, body)
}
// Levels contains hook levels to be catched
func (hook *logHook) Levels() []logrus.Level {
levels := []logrus.Level{}
for _, v := range hook.LevelsParam {
lv, _ := logrus.ParseLevel(v)
levels = append(levels, lv)
}
return levels
}