Implemented getSelectedCandidatePair() for libjuice

deps/libjuice

@@ -1 +1 @@
-Subproject commit 92fc9e7a9d8cd19a5c5d59cbc0a11cc9f684483b
+Subproject commit 6942c8b521dad09dd5d380bf580cdc008562f55e

src/candidate.cpp

@@ -52,10 +52,12 @@ Candidate::Candidate(string candidate, string mid)
     : mFamily(Family::Unresolved), mType(Type::Unknown), mTransportType(TransportType::Unknown),
       mPort(0), mPriority(0) {
 
-	const std::array prefixes{"a=", "candidate:"};
-	for (const string &prefix : prefixes)
-		if (hasprefix(candidate, prefix))
-			candidate.erase(0, prefix.size());
+	if (!candidate.empty()) {
+		const std::array prefixes{"a=", "candidate:"};
+		for (const string &prefix : prefixes)
+			if (hasprefix(candidate, prefix))
+				candidate.erase(0, prefix.size());
+	}
 
 	mCandidate = std::move(candidate);
 	mMid = std::move(mid);

src/icetransport.cpp

@@ -187,6 +187,24 @@ std::optional<string> IceTransport::getRemoteAddress() const {
 	return nullopt;
 }
 
+bool IceTransport::getSelectedCandidatePair(Candidate *local, Candidate *remote) {
+	char sdpLocal[JUICE_MAX_CANDIDATE_SDP_STRING_LEN];
+	char sdpRemote[JUICE_MAX_CANDIDATE_SDP_STRING_LEN];
+	if (juice_get_selected_candidates(mAgent.get(), sdpLocal, JUICE_MAX_CANDIDATE_SDP_STRING_LEN,
+	                                 sdpRemote, JUICE_MAX_CANDIDATE_SDP_STRING_LEN) == 0) {
+		if (local) {
+			*local = Candidate(sdpLocal);
+			local->resolve(Candidate::ResolveMode::Simple);
+		}
+		if (remote) {
+			*remote = Candidate(sdpRemote);
+			remote->resolve(Candidate::ResolveMode::Simple);
+		}
+		return true;
+	}
+	return false;
+}
+
 bool IceTransport::send(message_ptr message) {
 	auto s = state();
 	if (!message || (s != State::Connected && s != State::Completed))
@@ -729,8 +747,10 @@ bool IceTransport::getSelectedCandidatePair(Candidate *local, Candidate *remote)
 	if(remote) *remote = Candidate(sdpRemote);
 	g_free(sdpRemote);
 
-	local->resolve(Candidate::ResolveMode::Simple);
-	remote->resolve(Candidate::ResolveMode::Simple);
+	if (local)
+		local->resolve(Candidate::ResolveMode::Simple);
+	if (remote)
+		remote->resolve(Candidate::ResolveMode::Simple);
 	return true;
 }
 

src/icetransport.hpp

@@ -63,9 +63,7 @@ public:
 	bool stop() override;
 	bool send(message_ptr message) override; // false if dropped
 
-#if USE_NICE
 	bool getSelectedCandidatePair(Candidate *local, Candidate *remote);
-#endif
 
 private:
 	bool outgoing(message_ptr message) override;

src/peerconnection.cpp

@@ -902,13 +902,8 @@ void PeerConnection::resetCallbacks() {
 
 bool PeerConnection::getSelectedCandidatePair([[maybe_unused]] Candidate *local,
                                               [[maybe_unused]] Candidate *remote) {
-#if USE_NICE
 	auto iceTransport = std::atomic_load(&mIceTransport);
-	return iceTransport->getSelectedCandidatePair(local, remote);
-#else
-	PLOG_WARNING << "getSelectedCandidatePair() is only implemented with libnice as ICE backend";
-	return false;
-#endif
+	return iceTransport ? iceTransport->getSelectedCandidatePair(local, remote) : false;
 }
 
 void PeerConnection::clearStats() {

test/connectivity.cpp

@@ -147,6 +147,16 @@ void test_connectivity() {
 	if (auto addr = pc2->remoteAddress())
 		cout << "Remote address 2: " << *addr << endl;
 
+	Candidate local, remote;
+	if(pc1->getSelectedCandidatePair(&local, &remote)) {
+		cout << "Local candidate 1:  " << local << endl;
+		cout << "Remote candidate 1: " << remote << endl;
+	}
+	if(pc2->getSelectedCandidatePair(&local, &remote)) {
+		cout << "Local candidate 2:  " << local << endl;
+		cout << "Remote candidate 2: " << remote << endl;
+	}
+
 	// Try to open a second data channel with another label
 	shared_ptr<DataChannel> second2;
 	pc2->onDataChannel([&second2](shared_ptr<DataChannel> dc) {