Merge pull request #624 from libp2p/fix/optimize-when-no-events

fix: optimize for the case where we're not subscribing to query events

Author: Stebalien

dual/dual.go

@@ -97,7 +97,14 @@ func (dht *DHT) Provide(ctx context.Context, key cid.Cid, announce bool) error {
 func (dht *DHT) FindProvidersAsync(ctx context.Context, key cid.Cid, count int) <-chan peer.AddrInfo {
 	reqCtx, cancel := context.WithCancel(ctx)
 	outCh := make(chan peer.AddrInfo)
-	subCtx, evtCh := routing.RegisterForQueryEvents(reqCtx)
+
+	// Register for and merge query events if we care about them.
+	subCtx := reqCtx
+	var evtCh <-chan *routing.QueryEvent
+	if routing.SubscribesToQueryEvents(ctx) {
+		subCtx, evtCh = routing.RegisterForQueryEvents(reqCtx)
+	}
+
 	wanCh := dht.WAN.FindProvidersAsync(subCtx, key, count)
 	lanCh := dht.LAN.FindProvidersAsync(subCtx, key, count)
 	zeroCount := (count == 0)

go.mod

@@ -17,11 +17,11 @@ require (
 	github.com/jbenet/goprocess v0.1.4
 	github.com/libp2p/go-eventbus v0.1.0
 	github.com/libp2p/go-libp2p v0.8.2
-	github.com/libp2p/go-libp2p-core v0.5.2
+	github.com/libp2p/go-libp2p-core v0.5.3
 	github.com/libp2p/go-libp2p-kbucket v0.4.1
 	github.com/libp2p/go-libp2p-peerstore v0.2.3
 	github.com/libp2p/go-libp2p-record v0.1.2
-	github.com/libp2p/go-libp2p-routing-helpers v0.2.1
+	github.com/libp2p/go-libp2p-routing-helpers v0.2.3
 	github.com/libp2p/go-libp2p-swarm v0.2.3
 	github.com/libp2p/go-libp2p-testing v0.1.1
 	github.com/libp2p/go-msgio v0.0.4

go.sum

@@ -244,6 +244,8 @@ github.com/libp2p/go-libp2p-core v0.5.1 h1:6Cu7WljPQtGY2krBlMoD8L/zH3tMUsCbqNFH7
 github.com/libp2p/go-libp2p-core v0.5.1/go.mod h1:uN7L2D4EvPCvzSH5SrhR72UWbnSGpt5/a35Sm4upn4Y=
 github.com/libp2p/go-libp2p-core v0.5.2 h1:hevsCcdLiazurKBoeNn64aPYTVOPdY4phaEGeLtHOAs=
 github.com/libp2p/go-libp2p-core v0.5.2/go.mod h1:uN7L2D4EvPCvzSH5SrhR72UWbnSGpt5/a35Sm4upn4Y=
+github.com/libp2p/go-libp2p-core v0.5.3 h1:b9W3w7AZR2n/YJhG8d0qPFGhGhCWKIvPuJgp4hhc4MM=
+github.com/libp2p/go-libp2p-core v0.5.3/go.mod h1:uN7L2D4EvPCvzSH5SrhR72UWbnSGpt5/a35Sm4upn4Y=
 github.com/libp2p/go-libp2p-crypto v0.1.0 h1:k9MFy+o2zGDNGsaoZl0MA3iZ75qXxr9OOoAZF+sD5OQ=
 github.com/libp2p/go-libp2p-crypto v0.1.0/go.mod h1:sPUokVISZiy+nNuTTH/TY+leRSxnFj/2GLjtOTW90hI=
 github.com/libp2p/go-libp2p-discovery v0.2.0 h1:1p3YSOq7VsgaL+xVHPi8XAmtGyas6D2J6rWBEfz/aiY=
@@ -286,8 +288,8 @@ github.com/libp2p/go-libp2p-pnet v0.2.0 h1:J6htxttBipJujEjz1y0a5+eYoiPcFHhSYHH6n
 github.com/libp2p/go-libp2p-pnet v0.2.0/go.mod h1:Qqvq6JH/oMZGwqs3N1Fqhv8NVhrdYcO0BW4wssv21LA=
 github.com/libp2p/go-libp2p-record v0.1.2 h1:M50VKzWnmUrk/M5/Dz99qO9Xh4vs8ijsK+7HkJvRP+0=
 github.com/libp2p/go-libp2p-record v0.1.2/go.mod h1:pal0eNcT5nqZaTV7UGhqeGqxFgGdsU/9W//C8dqjQDk=
-github.com/libp2p/go-libp2p-routing-helpers v0.2.1 h1:tV5fxxkl1cEEFXIv9yl5OGbLjEwngtq1qf5G/beLRvQ=
-github.com/libp2p/go-libp2p-routing-helpers v0.2.1/go.mod h1:rTLUHlGDZbXHANJAWP2xW7ruPNJLj41/GnCBiR+qgjU=
+github.com/libp2p/go-libp2p-routing-helpers v0.2.3 h1:xY61alxJ6PurSi+MXbywZpelvuU4U4p/gPTxjqCqTzY=
+github.com/libp2p/go-libp2p-routing-helpers v0.2.3/go.mod h1:795bh+9YeoFl99rMASoiVgHdi5bjack0N1+AFAdbvBw=
 github.com/libp2p/go-libp2p-secio v0.1.0/go.mod h1:tMJo2w7h3+wN4pgU2LSYeiKPrfqBgkOsdiKK77hE7c8=
 github.com/libp2p/go-libp2p-secio v0.2.0 h1:ywzZBsWEEz2KNTn5RtzauEDq5RFEefPsttXYwAWqHng=
 github.com/libp2p/go-libp2p-secio v0.2.0/go.mod h1:2JdZepB8J5V9mBp79BmwsaPQhRPNN2NrnB2lKQcdy6g=