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server/vendor/github.com/pion/ice/v2/candidatepair.go

@@ -0,0 +1,136 @@
+// SPDX-FileCopyrightText: 2023 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+package ice
+
+import (
+	"fmt"
+	"sync/atomic"
+	"time"
+
+	"github.com/pion/stun"
+)
+
+func newCandidatePair(local, remote Candidate, controlling bool) *CandidatePair {
+	return &CandidatePair{
+		iceRoleControlling: controlling,
+		Remote:             remote,
+		Local:              local,
+		state:              CandidatePairStateWaiting,
+	}
+}
+
+// CandidatePair is a combination of a
+// local and remote candidate
+type CandidatePair struct {
+	iceRoleControlling       bool
+	Remote                   Candidate
+	Local                    Candidate
+	bindingRequestCount      uint16
+	state                    CandidatePairState
+	nominated                bool
+	nominateOnBindingSuccess bool
+
+	// stats
+	currentRoundTripTime int64 // in ns
+	totalRoundTripTime   int64 // in ns
+	responsesReceived    uint64
+}
+
+func (p *CandidatePair) String() string {
+	if p == nil {
+		return ""
+	}
+
+	return fmt.Sprintf("prio %d (local, prio %d) %s <-> %s (remote, prio %d), state: %s, nominated: %v, nominateOnBindingSuccess: %v",
+		p.priority(), p.Local.Priority(), p.Local, p.Remote, p.Remote.Priority(), p.state, p.nominated, p.nominateOnBindingSuccess)
+}
+
+func (p *CandidatePair) equal(other *CandidatePair) bool {
+	if p == nil && other == nil {
+		return true
+	}
+	if p == nil || other == nil {
+		return false
+	}
+	return p.Local.Equal(other.Local) && p.Remote.Equal(other.Remote)
+}
+
+// RFC 5245 - 5.7.2.  Computing Pair Priority and Ordering Pairs
+// Let G be the priority for the candidate provided by the controlling
+// agent.  Let D be the priority for the candidate provided by the
+// controlled agent.
+// pair priority = 2^32*MIN(G,D) + 2*MAX(G,D) + (G>D?1:0)
+func (p *CandidatePair) priority() uint64 {
+	var g, d uint32
+	if p.iceRoleControlling {
+		g = p.Local.Priority()
+		d = p.Remote.Priority()
+	} else {
+		g = p.Remote.Priority()
+		d = p.Local.Priority()
+	}
+
+	// Just implement these here rather
+	// than fooling around with the math package
+	min := func(x, y uint32) uint64 {
+		if x < y {
+			return uint64(x)
+		}
+		return uint64(y)
+	}
+	max := func(x, y uint32) uint64 {
+		if x > y {
+			return uint64(x)
+		}
+		return uint64(y)
+	}
+	cmp := func(x, y uint32) uint64 {
+		if x > y {
+			return uint64(1)
+		}
+		return uint64(0)
+	}
+
+	// 1<<32 overflows uint32; and if both g && d are
+	// maxUint32, this result would overflow uint64
+	return (1<<32-1)*min(g, d) + 2*max(g, d) + cmp(g, d)
+}
+
+func (p *CandidatePair) Write(b []byte) (int, error) {
+	return p.Local.writeTo(b, p.Remote)
+}
+
+func (a *Agent) sendSTUN(msg *stun.Message, local, remote Candidate) {
+	_, err := local.writeTo(msg.Raw, remote)
+	if err != nil {
+		a.log.Tracef("Failed to send STUN message: %s", err)
+	}
+}
+
+// UpdateRoundTripTime sets the current round time of this pair and
+// accumulates total round trip time and responses received
+func (p *CandidatePair) UpdateRoundTripTime(rtt time.Duration) {
+	rttNs := rtt.Nanoseconds()
+	atomic.StoreInt64(&p.currentRoundTripTime, rttNs)
+	atomic.AddInt64(&p.totalRoundTripTime, rttNs)
+	atomic.AddUint64(&p.responsesReceived, 1)
+}
+
+// CurrentRoundTripTime returns the current round trip time in seconds
+// https://www.w3.org/TR/webrtc-stats/#dom-rtcicecandidatepairstats-currentroundtriptime
+func (p *CandidatePair) CurrentRoundTripTime() float64 {
+	return time.Duration(atomic.LoadInt64(&p.currentRoundTripTime)).Seconds()
+}
+
+// TotalRoundTripTime returns the current round trip time in seconds
+// https://www.w3.org/TR/webrtc-stats/#dom-rtcicecandidatepairstats-totalroundtriptime
+func (p *CandidatePair) TotalRoundTripTime() float64 {
+	return time.Duration(atomic.LoadInt64(&p.totalRoundTripTime)).Seconds()
+}
+
+// ResponsesReceived returns the total number of connectivity responses received
+// https://www.w3.org/TR/webrtc-stats/#dom-rtcicecandidatepairstats-responsesreceived
+func (p *CandidatePair) ResponsesReceived() uint64 {
+	return atomic.LoadUint64(&p.responsesReceived)
+}