59 lines
1.3 KiB
Go
59 lines
1.3 KiB
Go
package swift
|
|
|
|
import (
|
|
"io"
|
|
"time"
|
|
)
|
|
|
|
// An io.ReadCloser which obeys an idle timeout
|
|
type timeoutReader struct {
|
|
reader io.ReadCloser
|
|
timeout time.Duration
|
|
cancel func()
|
|
}
|
|
|
|
// Returns a wrapper around the reader which obeys an idle
|
|
// timeout. The cancel function is called if the timeout happens
|
|
func newTimeoutReader(reader io.ReadCloser, timeout time.Duration, cancel func()) *timeoutReader {
|
|
return &timeoutReader{
|
|
reader: reader,
|
|
timeout: timeout,
|
|
cancel: cancel,
|
|
}
|
|
}
|
|
|
|
// Read reads up to len(p) bytes into p
|
|
//
|
|
// Waits at most for timeout for the read to complete otherwise returns a timeout
|
|
func (t *timeoutReader) Read(p []byte) (int, error) {
|
|
// FIXME limit the amount of data read in one chunk so as to not exceed the timeout?
|
|
// Do the read in the background
|
|
type result struct {
|
|
n int
|
|
err error
|
|
}
|
|
done := make(chan result, 1)
|
|
go func() {
|
|
n, err := t.reader.Read(p)
|
|
done <- result{n, err}
|
|
}()
|
|
// Wait for the read or the timeout
|
|
timer := time.NewTimer(t.timeout)
|
|
defer timer.Stop()
|
|
select {
|
|
case r := <-done:
|
|
return r.n, r.err
|
|
case <-timer.C:
|
|
t.cancel()
|
|
return 0, TimeoutError
|
|
}
|
|
panic("unreachable") // for Go 1.0
|
|
}
|
|
|
|
// Close the channel
|
|
func (t *timeoutReader) Close() error {
|
|
return t.reader.Close()
|
|
}
|
|
|
|
// Check it satisfies the interface
|
|
var _ io.ReadCloser = &timeoutReader{}
|