snapshot of https://github.com/pion/webrtc.git (main, 2026-09-15; blobs > 131072B omitted)

srtp_writer_future.go

@@ -0,0 +1,141 @@
+// SPDX-FileCopyrightText: 2026 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+//go:build !js
+
+package webrtc
+
+import (
+	"io"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/pion/rtp"
+	"github.com/pion/srtp/v3"
+)
+
+// srtpWriterFuture blocks Read/Write calls until
+// the SRTP Session is available.
+type srtpWriterFuture struct {
+	ssrc           SSRC
+	rtpSender      *RTPSender
+	rtcpReadStream atomic.Value // *srtp.ReadStreamSRTCP
+	rtpWriteStream atomic.Value // *srtp.WriteStreamSRTP
+	mu             sync.Mutex
+	closed         bool
+}
+
+func (s *srtpWriterFuture) init(returnWhenNoSRTP bool) error { //nolint:cyclop
+	if returnWhenNoSRTP {
+		select {
+		case <-s.rtpSender.stopCalled:
+			return io.ErrClosedPipe
+		case <-s.rtpSender.transport.srtpReady:
+		default:
+			return nil
+		}
+	} else {
+		select {
+		case <-s.rtpSender.stopCalled:
+			return io.ErrClosedPipe
+		case <-s.rtpSender.transport.srtpReady:
+		}
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.closed {
+		return io.ErrClosedPipe
+	}
+
+	srtcpSession, err := s.rtpSender.transport.getSRTCPSession()
+	if err != nil {
+		return err
+	}
+
+	rtcpReadStream, err := srtcpSession.OpenReadStream(uint32(s.ssrc))
+	if err != nil {
+		return err
+	}
+
+	srtpSession, err := s.rtpSender.transport.getSRTPSession()
+	if err != nil {
+		return err
+	}
+
+	rtpWriteStream, err := srtpSession.OpenWriteStream()
+	if err != nil {
+		return err
+	}
+
+	s.rtcpReadStream.Store(rtcpReadStream)
+	s.rtpWriteStream.Store(rtpWriteStream)
+
+	return nil
+}
+
+func (s *srtpWriterFuture) Close() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.closed {
+		return nil
+	}
+	s.closed = true
+
+	if value, ok := s.rtcpReadStream.Load().(*srtp.ReadStreamSRTCP); ok {
+		return value.Close()
+	}
+
+	return nil
+}
+
+func (s *srtpWriterFuture) Read(b []byte) (n int, err error) {
+	if value, ok := s.rtcpReadStream.Load().(*srtp.ReadStreamSRTCP); ok {
+		return value.Read(b)
+	}
+
+	if err := s.init(false); err != nil || s.rtcpReadStream.Load() == nil {
+		return 0, err
+	}
+
+	return s.Read(b)
+}
+
+func (s *srtpWriterFuture) SetReadDeadline(t time.Time) error {
+	if value, ok := s.rtcpReadStream.Load().(*srtp.ReadStreamSRTCP); ok {
+		return value.SetReadDeadline(t)
+	}
+
+	if err := s.init(false); err != nil || s.rtcpReadStream.Load() == nil {
+		return err
+	}
+
+	return s.SetReadDeadline(t)
+}
+
+func (s *srtpWriterFuture) WriteRTP(header *rtp.Header, payload []byte) (int, error) {
+	if value, ok := s.rtpWriteStream.Load().(*srtp.WriteStreamSRTP); ok {
+		return value.WriteRTP(header, payload)
+	}
+
+	if err := s.init(true); err != nil || s.rtpWriteStream.Load() == nil {
+		return 0, err
+	}
+
+	return s.WriteRTP(header, payload)
+}
+
+func (s *srtpWriterFuture) Write(b []byte) (int, error) {
+	if value, ok := s.rtpWriteStream.Load().(*srtp.WriteStreamSRTP); ok {
+		return value.Write(b)
+	}
+
+	if err := s.init(true); err != nil || s.rtpWriteStream.Load() == nil {
+		return 0, err
+	}
+
+	return s.Write(b)
+}