multi: move block epochs dependency from links to switch

In this commit, we move the block height dependency from the links in
the switch to the switch itself. This is possible due to a recent change
on the links no longer depending on the block height to update their
commitment fees.

We'll now only have the switch be alerted of new blocks coming in and
links will retrieve the height from it atomically.

htlcswitch/test_utils.go

@@ -17,7 +17,6 @@ import (
 	"github.com/btcsuite/fastsha256"
 	"github.com/coreos/bbolt"
 	"github.com/go-errors/errors"
-	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/contractcourt"
 	"github.com/lightningnetwork/lnd/keychain"
@@ -569,22 +568,13 @@ func generateRoute(hops ...ForwardingInfo) ([lnwire.OnionPacketSize]byte, error)
 type threeHopNetwork struct {
 	aliceServer      *mockServer
 	aliceChannelLink *channelLink
-	aliceBlockEpoch  chan *chainntnfs.BlockEpoch
-	aliceTicker      *time.Ticker
-
-	firstBobChannelLink *channelLink
-	bobFirstBlockEpoch  chan *chainntnfs.BlockEpoch
-	firstBobTicker      *time.Ticker
 
 	bobServer            *mockServer
+	firstBobChannelLink  *channelLink
 	secondBobChannelLink *channelLink
-	bobSecondBlockEpoch  chan *chainntnfs.BlockEpoch
-	secondBobTicker      *time.Ticker
 
-	carolChannelLink *channelLink
 	carolServer      *mockServer
-	carolBlockEpoch  chan *chainntnfs.BlockEpoch
-	carolTicker      *time.Ticker
+	carolChannelLink *channelLink
 
 	feeEstimator *mockFeeEstimator
 
@@ -762,11 +752,6 @@ func (n *threeHopNetwork) stop() {
 		done <- struct{}{}
 	}()
 
-	n.aliceTicker.Stop()
-	n.firstBobTicker.Stop()
-	n.secondBobTicker.Stop()
-	n.carolTicker.Stop()
-
 	for i := 0; i < 3; i++ {
 		<-done
 	}
@@ -858,15 +843,15 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 	carolDb := carolChannel.State().Db
 
 	// Create three peers/servers.
-	aliceServer, err := newMockServer(t, "alice", aliceDb)
+	aliceServer, err := newMockServer(t, "alice", startingHeight, aliceDb)
 	if err != nil {
 		t.Fatalf("unable to create alice server: %v", err)
 	}
-	bobServer, err := newMockServer(t, "bob", bobDb)
+	bobServer, err := newMockServer(t, "bob", startingHeight, bobDb)
 	if err != nil {
 		t.Fatalf("unable to create bob server: %v", err)
 	}
-	carolServer, err := newMockServer(t, "carol", carolDb)
+	carolServer, err := newMockServer(t, "carol", startingHeight, carolDb)
 	if err != nil {
 		t.Fatalf("unable to create carol server: %v", err)
 	}
@@ -900,13 +885,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 	}
 	obfuscator := NewMockObfuscator()
 
-	aliceEpochChan := make(chan *chainntnfs.BlockEpoch)
-	aliceEpoch := &chainntnfs.BlockEpochEvent{
-		Epochs: aliceEpochChan,
-		Cancel: func() {
-		},
-	}
-	aliceTicker := time.NewTicker(50 * time.Millisecond)
 	aliceChannelLink := NewChannelLink(
 		ChannelLinkConfig{
 			Switch:             aliceServer.htlcSwitch,
@@ -921,7 +899,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 			},
 			FetchLastChannelUpdate: mockGetChanUpdateMessage,
 			Registry:               aliceServer.registry,
-			BlockEpochs:            aliceEpoch,
 			FeeEstimator:           feeEstimator,
 			PreimageCache:          pCache,
 			UpdateContractSignals: func(*contractcourt.ContractSignals) error {
@@ -937,7 +914,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 			OnChannelFailure:    func(lnwire.ChannelID, lnwire.ShortChannelID, LinkFailureError) {},
 		},
 		aliceChannel,
-		startingHeight,
 	)
 	if err := aliceServer.htlcSwitch.AddLink(aliceChannelLink); err != nil {
 		t.Fatalf("unable to add alice channel link: %v", err)
@@ -952,13 +928,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 		}
 	}()
 
-	bobFirstEpochChan := make(chan *chainntnfs.BlockEpoch)
-	bobFirstEpoch := &chainntnfs.BlockEpochEvent{
-		Epochs: bobFirstEpochChan,
-		Cancel: func() {
-		},
-	}
-	firstBobTicker := time.NewTicker(50 * time.Millisecond)
 	firstBobChannelLink := NewChannelLink(
 		ChannelLinkConfig{
 			Switch:             bobServer.htlcSwitch,
@@ -973,7 +942,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 			},
 			FetchLastChannelUpdate: mockGetChanUpdateMessage,
 			Registry:               bobServer.registry,
-			BlockEpochs:            bobFirstEpoch,
 			FeeEstimator:           feeEstimator,
 			PreimageCache:          pCache,
 			UpdateContractSignals: func(*contractcourt.ContractSignals) error {
@@ -989,7 +957,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 			OnChannelFailure:    func(lnwire.ChannelID, lnwire.ShortChannelID, LinkFailureError) {},
 		},
 		firstBobChannel,
-		startingHeight,
 	)
 	if err := bobServer.htlcSwitch.AddLink(firstBobChannelLink); err != nil {
 		t.Fatalf("unable to add first bob channel link: %v", err)
@@ -1004,13 +971,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 		}
 	}()
 
-	bobSecondEpochChan := make(chan *chainntnfs.BlockEpoch)
-	bobSecondEpoch := &chainntnfs.BlockEpochEvent{
-		Epochs: bobSecondEpochChan,
-		Cancel: func() {
-		},
-	}
-	secondBobTicker := time.NewTicker(50 * time.Millisecond)
 	secondBobChannelLink := NewChannelLink(
 		ChannelLinkConfig{
 			Switch:             bobServer.htlcSwitch,
@@ -1025,7 +985,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 			},
 			FetchLastChannelUpdate: mockGetChanUpdateMessage,
 			Registry:               bobServer.registry,
-			BlockEpochs:            bobSecondEpoch,
 			FeeEstimator:           feeEstimator,
 			PreimageCache:          pCache,
 			UpdateContractSignals: func(*contractcourt.ContractSignals) error {
@@ -1041,7 +1000,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 			OnChannelFailure:    func(lnwire.ChannelID, lnwire.ShortChannelID, LinkFailureError) {},
 		},
 		secondBobChannel,
-		startingHeight,
 	)
 	if err := bobServer.htlcSwitch.AddLink(secondBobChannelLink); err != nil {
 		t.Fatalf("unable to add second bob channel link: %v", err)
@@ -1056,13 +1014,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 		}
 	}()
 
-	carolBlockEpoch := make(chan *chainntnfs.BlockEpoch)
-	carolEpoch := &chainntnfs.BlockEpochEvent{
-		Epochs: bobSecondEpochChan,
-		Cancel: func() {
-		},
-	}
-	carolTicker := time.NewTicker(50 * time.Millisecond)
 	carolChannelLink := NewChannelLink(
 		ChannelLinkConfig{
 			Switch:             carolServer.htlcSwitch,
@@ -1077,7 +1028,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 			},
 			FetchLastChannelUpdate: mockGetChanUpdateMessage,
 			Registry:               carolServer.registry,
-			BlockEpochs:            carolEpoch,
 			FeeEstimator:           feeEstimator,
 			PreimageCache:          pCache,
 			UpdateContractSignals: func(*contractcourt.ContractSignals) error {
@@ -1093,7 +1043,6 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 			OnChannelFailure:    func(lnwire.ChannelID, lnwire.ShortChannelID, LinkFailureError) {},
 		},
 		carolChannel,
-		startingHeight,
 	)
 	if err := carolServer.htlcSwitch.AddLink(carolChannelLink); err != nil {
 		t.Fatalf("unable to add carol channel link: %v", err)
@@ -1111,22 +1060,13 @@ func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel,
 	return &threeHopNetwork{
 		aliceServer:      aliceServer,
 		aliceChannelLink: aliceChannelLink.(*channelLink),
-		aliceBlockEpoch:  aliceEpochChan,
-		aliceTicker:      aliceTicker,
-
-		firstBobChannelLink: firstBobChannelLink.(*channelLink),
-		bobFirstBlockEpoch:  bobFirstEpochChan,
-		firstBobTicker:      firstBobTicker,
 
 		bobServer:            bobServer,
+		firstBobChannelLink:  firstBobChannelLink.(*channelLink),
 		secondBobChannelLink: secondBobChannelLink.(*channelLink),
-		bobSecondBlockEpoch:  bobSecondEpochChan,
-		secondBobTicker:      secondBobTicker,
 
-		carolChannelLink: carolChannelLink.(*channelLink),
 		carolServer:      carolServer,
-		carolBlockEpoch:  carolBlockEpoch,
-		carolTicker:      carolTicker,
+		carolChannelLink: carolChannelLink.(*channelLink),
 
 		feeEstimator: feeEstimator,
 		globalPolicy: globalPolicy,