Flexible mechanism to make execution flow interruptible.
The breaker carries a cancellation signal to interrupt an action execution.
interrupter := breaker.Multiplex(
breaker.BreakByContext(context.WithTimeout(req.Context(), time.Minute)),
breaker.BreakByDeadline(NewYear),
breaker.BreakBySignal(os.Interrupt),
)
defer interrupter.Close()
<-interrupter.Done() // wait context cancellation, timeout or interrupt signalFull description of the idea is available here.
I have to make retry package:
if err := retry.Retry(breaker.BreakByTimeout(time.Minute), action); err != nil {
log.Fatal(err)
}and semaphore package:
if err := semaphore.Acquire(breaker.BreakByTimeout(time.Minute), 5); err != nil {
log.Fatal(err)
}more consistent and reliable.
import (
"bytes"
"context"
"fmt"
"io"
"net/http"
"os"
"time"
"github.com/kamilsk/breaker"
)
var NewYear = time.Time{}.AddDate(time.Now().Year(), 0, 0)
func Handle(rw http.ResponseWriter, req *http.Request) {
ctx, cancel := context.WithCancel(req.Context())
defer cancel()
deadline, _ := time.ParseDuration(req.Header.Get("X-Timeout"))
interrupter := breaker.Multiplex(
breaker.BreakByContext(context.WithTimeout(ctx, deadline)),
breaker.BreakByDeadline(NewYear),
breaker.BreakBySignal(os.Interrupt),
)
defer interrupter.Close()
buf, work := bytes.NewBuffer(nil), Work(ctx, struct{}{})
for {
select {
case b, ok := <-work:
if !ok {
rw.WriteHeader(http.StatusOK)
io.Copy(rw, buf)
return
}
buf.WriteByte(b)
case <-interrupter.Done():
rw.WriteHeader(http.StatusPartialContent)
rw.Header().Set("Content-Range", fmt.Sprintf("bytes=0-%d", buf.Len()))
io.Copy(rw, buf)
return
}
}
}
func Work(ctx context.Context, _ struct{}) <-chan byte {
outcome := make(chan byte, 1)
go func() { ... }()
return outcome
}The library uses SemVer for versioning, and it is not BC-safe through major releases. You can use go modules to manage its version.
$ go get github.com/kamilsk/breaker@latestmade with ❤️ for everyone