mirror of
https://github.com/pion/webrtc.git
synced 2024-05-03 11:54:53 +08:00
68 lines
1.8 KiB
Go
68 lines
1.8 KiB
Go
// SPDX-FileCopyrightText: 2023 The Pion community <https://pion.ly>
|
|
// SPDX-License-Identifier: MIT
|
|
|
|
package webrtc
|
|
|
|
import (
|
|
"fmt"
|
|
"strings"
|
|
)
|
|
|
|
// ExampleGatheringCompletePromise demonstrates how to implement
|
|
// non-trickle ICE in Pion, an older form of ICE that does not require an
|
|
// asynchronous side channel between peers: negotiation is just a single
|
|
// offer-answer exchange. It works by explicitly waiting for all local
|
|
// ICE candidates to have been gathered before sending an offer to the peer.
|
|
func ExampleGatheringCompletePromise() {
|
|
// create a peer connection
|
|
pc, err := NewPeerConnection(Configuration{})
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
defer func() {
|
|
closeErr := pc.Close()
|
|
if closeErr != nil {
|
|
panic(closeErr)
|
|
}
|
|
}()
|
|
|
|
// add at least one transceiver to the peer connection, or nothing
|
|
// interesting will happen. This could use pc.AddTrack instead.
|
|
_, err = pc.AddTransceiverFromKind(RTPCodecTypeVideo)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
// create a first offer that does not contain any local candidates
|
|
offer, err := pc.CreateOffer(nil)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
// gatherComplete is a channel that will be closed when
|
|
// the gathering of local candidates is complete.
|
|
gatherComplete := GatheringCompletePromise(pc)
|
|
|
|
// apply the offer
|
|
err = pc.SetLocalDescription(offer)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
// wait for gathering of local candidates to complete
|
|
<-gatherComplete
|
|
|
|
// compute the local offer again
|
|
offer2 := pc.LocalDescription()
|
|
|
|
// this second offer contains all candidates, and may be sent to
|
|
// the peer with no need for further communication. In this
|
|
// example, we simply check that it contains at least one
|
|
// candidate.
|
|
hasCandidate := strings.Contains(offer2.SDP, "\na=candidate:")
|
|
if hasCandidate {
|
|
fmt.Println("Ok!")
|
|
}
|
|
// Output: Ok!
|
|
}
|