CancelReader
A cancelable reader for Go
This package is based on the fantastic work of Erik Geiser in Charm's Bubble Tea framework.
Usage
NewReader returns a reader with a Cancel function. If the input reader is an *os.File, the cancel function can be used to interrupt a blocking Read call. In this case, the cancel function returns true if the call was canceled successfully. If the input reader is not an *os.File, the cancel function does nothing and always returns false.
r, err := cancelreader.NewReader(file)
if err != nil {
// handle error
...
}
// cancel after five seconds
go func() {
time.Sleep(5 * time.Second)
r.Cancel()
}()
// keep reading
for {
var buf [1024]byte
_, err := r.Read(buf[:])
if errors.Is(err, cancelreader.ErrCanceled) {
fmt.Println("canceled!")
break
}
if err != nil {
// handle other errors
...
}
// handle data
...
}
Implementations
- The Linux implementation is based on the epoll mechanism
- The BSD and macOS implementation is based on the kqueue mechanism
- The generic Unix implementation is based on the posix select syscall
Caution
The Windows implementation is based on WaitForMultipleObject with overlapping reads from CONIN$. At this point it only supports canceling reads from os.Stdin.
