cloudflared-mirror/quic/safe_stream.go

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package quic
import (
"sync"
"time"
"github.com/lucas-clemente/quic-go"
)
type SafeStreamCloser struct {
lock sync.Mutex
stream quic.Stream
}
func NewSafeStreamCloser(stream quic.Stream) *SafeStreamCloser {
return &SafeStreamCloser{
stream: stream,
}
}
func (s *SafeStreamCloser) Read(p []byte) (n int, err error) {
return s.stream.Read(p)
}
func (s *SafeStreamCloser) Write(p []byte) (n int, err error) {
s.lock.Lock()
defer s.lock.Unlock()
return s.stream.Write(p)
}
func (s *SafeStreamCloser) Close() error {
// Make sure a possible writer does not block the lock forever. We need it, so we can close the writer
// side of the stream safely.
_ = s.stream.SetWriteDeadline(time.Now())
// This lock is eventually acquired despite Write also acquiring it, because we set a deadline to writes.
s.lock.Lock()
defer s.lock.Unlock()
// We have to clean up the receiving stream ourselves since the Close in the bottom does not handle that.
s.stream.CancelRead(0)
return s.stream.Close()
}
func (s *SafeStreamCloser) CloseWrite() error {
s.lock.Lock()
defer s.lock.Unlock()
// As documented by the quic-go library, this doesn't actually close the entire stream.
// It prevents further writes, which in turn will result in an EOF signal being sent the other side of stream when
// reading.
// We can still read from this stream.
return s.stream.Close()
}