Merge pull request #3654 from Roasbeef/external-funding-chantype-bits

multi: convert the existing channeldb.ChannelType uint8 into a bit field

breacharbiter_test.go

@@ -1865,7 +1865,7 @@ func createInitChannels(revocationWindow int) (*lnwallet.LightningChannel, *lnwa
 		IdentityPub:             aliceKeyPub,
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,
-		ChanType:                channeldb.SingleFunderTweakless,
+		ChanType:                channeldb.SingleFunderTweaklessBit,
 		IsInitiator:             true,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: bobCommitPoint,
@@ -1883,7 +1883,7 @@ func createInitChannels(revocationWindow int) (*lnwallet.LightningChannel, *lnwa
 		IdentityPub:             bobKeyPub,
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,
-		ChanType:                channeldb.SingleFunderTweakless,
+		ChanType:                channeldb.SingleFunderTweaklessBit,
 		IsInitiator:             false,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: aliceCommitPoint,

chanbackup/single_test.go

@@ -124,9 +124,9 @@ func genRandomOpenChannelShell() (*channeldb.OpenChannel, error) {
 		isInitiator = true
 	}
 
-	chanType := channeldb.SingleFunder
+	chanType := channeldb.SingleFunderBit
 	if rand.Int63()%2 == 0 {
-		chanType = channeldb.SingleFunderTweakless
+		chanType = channeldb.SingleFunderTweaklessBit
 	}
 
 	return &channeldb.OpenChannel{

channeldb/channel.go

@@ -125,39 +125,45 @@ var (
 // ChannelType is an enum-like type that describes one of several possible
 // channel types. Each open channel is associated with a particular type as the
 // channel type may determine how higher level operations are conducted such as
-// fee negotiation, channel closing, the format of HTLCs, etc.
-// TODO(roasbeef): split up per-chain?
+// fee negotiation, channel closing, the format of HTLCs, etc. Structure-wise,
+// a ChannelType is a bit field, with each bit denoting a modification from the
+// base channel type of single funder.
 type ChannelType uint8
 
 const (
 	// NOTE: iota isn't used here for this enum needs to be stable
 	// long-term as it will be persisted to the database.
 
-	// SingleFunder represents a channel wherein one party solely funds the
-	// entire capacity of the channel.
-	SingleFunder ChannelType = 0
+	// SingleFunderBit represents a channel wherein one party solely funds
+	// the entire capacity of the channel.
+	SingleFunderBit ChannelType = 0
 
-	// DualFunder represents a channel wherein both parties contribute
+	// DualFunderBit represents a channel wherein both parties contribute
 	// funds towards the total capacity of the channel. The channel may be
 	// funded symmetrically or asymmetrically.
-	DualFunder ChannelType = 1
+	DualFunderBit ChannelType = 1 << 0
 
 	// SingleFunderTweakless is similar to the basic SingleFunder channel
 	// type, but it omits the tweak for one's key in the commitment
 	// transaction of the remote party.
-	SingleFunderTweakless ChannelType = 2
+	SingleFunderTweaklessBit ChannelType = 1 << 1
 )
 
 // IsSingleFunder returns true if the channel type if one of the known single
 // funder variants.
 func (c ChannelType) IsSingleFunder() bool {
-	return c == SingleFunder || c == SingleFunderTweakless
+	return c&DualFunderBit == 0
+}
+
+// IsDualFunder returns true if the ChannelType has the DualFunderBit set.
+func (c ChannelType) IsDualFunder() bool {
+	return c&DualFunderBit == DualFunderBit
 }
 
 // IsTweakless returns true if the target channel uses a commitment that
 // doesn't tweak the key for the remote party.
 func (c ChannelType) IsTweakless() bool {
-	return c == SingleFunderTweakless
+	return c&SingleFunderTweaklessBit == SingleFunderTweaklessBit
 }
 
 // ChannelConstraints represents a set of constraints meant to allow a node to

channeldb/channel_test.go

@@ -187,7 +187,7 @@ func createTestChannelState(cdb *DB) (*OpenChannel, error) {
 	chanID := lnwire.NewShortChanIDFromInt(uint64(rand.Int63()))
 
 	return &OpenChannel{
-		ChanType:          SingleFunder,
+		ChanType:          SingleFunderBit,
 		ChainHash:         key,
 		FundingOutpoint:   wire.OutPoint{Hash: key, Index: rand.Uint32()},
 		ShortChannelID:    chanID,

chanrestore.go

@@ -87,10 +87,10 @@ func (c *chanDBRestorer) openChannelShell(backup chanbackup.Single) (
 	switch backup.Version {
 
 	case chanbackup.DefaultSingleVersion:
-		chanType = channeldb.SingleFunder
+		chanType = channeldb.SingleFunderBit
 
 	case chanbackup.TweaklessCommitVersion:
-		chanType = channeldb.SingleFunderTweakless
+		chanType = channeldb.SingleFunderTweaklessBit
 
 	default:
 		return nil, fmt.Errorf("unknown Single version: %v", err)

fundingmanager.go

@@ -521,7 +521,7 @@ func (f *fundingManager) start() error {
 			// Rebroadcast the funding transaction for any pending
 			// channel that we initiated. No error will be returned
 			// if the transaction already has been broadcasted.
-			if channel.ChanType == channeldb.SingleFunder &&
+			if channel.ChanType.IsSingleFunder() &&
 				channel.IsInitiator {
 
 				err := f.cfg.PublishTransaction(

htlcswitch/link.go

@@ -1860,11 +1860,9 @@ func (l *channelLink) handleUpstreamMsg(msg lnwire.Message) {
 			}
 
 			chanType := l.channel.State().ChanType
-			isTweakless := chanType == channeldb.SingleFunderTweakless
-
 			chanID := l.ChanID()
 			err = l.cfg.TowerClient.BackupState(
-				&chanID, breachInfo, isTweakless,
+				&chanID, breachInfo, chanType.IsTweakless(),
 			)
 			if err != nil {
 				l.fail(LinkFailureError{code: ErrInternalError},

htlcswitch/test_utils.go

@@ -328,7 +328,7 @@ func createTestChannel(alicePrivKey, bobPrivKey []byte,
 		RemoteChanCfg:           bobCfg,
 		IdentityPub:             aliceKeyPub,
 		FundingOutpoint:         *prevOut,
-		ChanType:                channeldb.SingleFunderTweakless,
+		ChanType:                channeldb.SingleFunderTweaklessBit,
 		IsInitiator:             true,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: bobCommitPoint,
@@ -347,7 +347,7 @@ func createTestChannel(alicePrivKey, bobPrivKey []byte,
 		RemoteChanCfg:           aliceCfg,
 		IdentityPub:             bobKeyPub,
 		FundingOutpoint:         *prevOut,
-		ChanType:                channeldb.SingleFunderTweakless,
+		ChanType:                channeldb.SingleFunderTweaklessBit,
 		IsInitiator:             false,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: aliceCommitPoint,

lnwallet/channel.go

@@ -868,8 +868,7 @@ func (lc *LightningChannel) diskCommitToMemCommit(isLocal bool,
 	// If this commit is tweakless, then it'll affect the way we derive our
 	// keys, which will affect the commitment transaction reconstruction.
 	// So we'll determine this first, before we do anything else.
-	tweaklessCommit := (lc.channelState.ChanType ==
-		channeldb.SingleFunderTweakless)
+	tweaklessCommit := lc.channelState.ChanType.IsTweakless()
 
 	// First, we'll need to re-derive the commitment key ring for each
 	// party used within this particular state. If this is a pending commit

lnwallet/interface_test.go

@@ -511,7 +511,7 @@ func testDualFundingReservationWorkflow(miner *rpctest.Harness,
 	if !bytes.Equal(aliceChannels[0].FundingOutpoint.Hash[:], fundingSha[:]) {
 		t.Fatalf("channel state not properly saved")
 	}
-	if aliceChannels[0].ChanType != channeldb.DualFunder {
+	if !aliceChannels[0].ChanType.IsDualFunder() {
 		t.Fatalf("channel not detected as dual funder")
 	}
 	bobChannels, err := bob.Cfg.Database.FetchOpenChannels(alicePub)
@@ -521,7 +521,7 @@ func testDualFundingReservationWorkflow(miner *rpctest.Harness,
 	if !bytes.Equal(bobChannels[0].FundingOutpoint.Hash[:], fundingSha[:]) {
 		t.Fatalf("channel state not properly saved")
 	}
-	if bobChannels[0].ChanType != channeldb.DualFunder {
+	if !bobChannels[0].ChanType.IsDualFunder() {
 		t.Fatalf("channel not detected as dual funder")
 	}
 
@@ -971,7 +971,7 @@ func testSingleFunderReservationWorkflow(miner *rpctest.Harness,
 	}
 	if !aliceChannels[0].ChanType.IsSingleFunder() {
 		t.Fatalf("channel type is incorrect, expected %v instead got %v",
-			channeldb.SingleFunder, aliceChannels[0].ChanType)
+			channeldb.SingleFunderBit, aliceChannels[0].ChanType)
 	}
 
 	bobChannels, err := bob.Cfg.Database.FetchOpenChannels(alicePub)
@@ -991,7 +991,7 @@ func testSingleFunderReservationWorkflow(miner *rpctest.Harness,
 	}
 	if !bobChannels[0].ChanType.IsSingleFunder() {
 		t.Fatalf("channel type is incorrect, expected %v instead got %v",
-			channeldb.SingleFunder, bobChannels[0].ChanType)
+			channeldb.SingleFunderBit, bobChannels[0].ChanType)
 	}
 
 	// Let Alice publish the funding transaction.

lnwallet/reservation.go

@@ -215,15 +215,15 @@ func NewChannelReservation(capacity, localFundingAmt btcutil.Amount,
 	// a single-funder channel.
 	if ourBalance == 0 || theirBalance == 0 || pushMSat != 0 {
 		if tweaklessCommit {
-			chanType = channeldb.SingleFunderTweakless
+			chanType |= channeldb.SingleFunderTweaklessBit
 		} else {
-			chanType = channeldb.SingleFunder
+			chanType |= channeldb.SingleFunderBit
 		}
 	} else {
 		// Otherwise, this is a dual funder channel, and no side is
 		// technically the "initiator"
 		initiator = false
-		chanType = channeldb.DualFunder
+		chanType |= channeldb.DualFunderBit
 	}
 
 	return &ChannelReservation{

lnwallet/test_utils.go

@@ -274,7 +274,7 @@ func CreateTestChannels(tweaklessCommits bool) (
 		IdentityPub:             aliceKeys[0].PubKey(),
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,
-		ChanType:                channeldb.SingleFunderTweakless,
+		ChanType:                channeldb.SingleFunderTweaklessBit,
 		IsInitiator:             true,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: bobCommitPoint,
@@ -292,7 +292,7 @@ func CreateTestChannels(tweaklessCommits bool) (
 		IdentityPub:             bobKeys[0].PubKey(),
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,
-		ChanType:                channeldb.SingleFunderTweakless,
+		ChanType:                channeldb.SingleFunderTweaklessBit,
 		IsInitiator:             false,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: aliceCommitPoint,
@@ -305,8 +305,8 @@ func CreateTestChannels(tweaklessCommits bool) (
 	}
 
 	if !tweaklessCommits {
-		aliceChannelState.ChanType = channeldb.SingleFunder
-		bobChannelState.ChanType = channeldb.SingleFunder
+		aliceChannelState.ChanType = channeldb.SingleFunderBit
+		bobChannelState.ChanType = channeldb.SingleFunderBit
 	}
 
 	aliceSigner := &input.MockSigner{Privkeys: aliceKeys}

lnwallet/transactions_test.go

@@ -370,7 +370,7 @@ func TestCommitmentAndHTLCTransactions(t *testing.T) {
 
 	// Manually construct a new LightningChannel.
 	channelState := channeldb.OpenChannel{
-		ChanType:        channeldb.SingleFunderTweakless,
+		ChanType:        channeldb.SingleFunderTweaklessBit,
 		ChainHash:       *tc.netParams.GenesisHash,
 		FundingOutpoint: tc.fundingOutpoint,
 		ShortChannelID:  tc.shortChanID,

test_utils.go

@@ -255,7 +255,7 @@ func createTestPeer(notifier chainntnfs.ChainNotifier,
 		IdentityPub:             aliceKeyPub,
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,
-		ChanType:                channeldb.SingleFunderTweakless,
+		ChanType:                channeldb.SingleFunderTweaklessBit,
 		IsInitiator:             true,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: bobCommitPoint,
@@ -272,7 +272,7 @@ func createTestPeer(notifier chainntnfs.ChainNotifier,
 		RemoteChanCfg:           aliceCfg,
 		IdentityPub:             bobKeyPub,
 		FundingOutpoint:         *prevOut,
-		ChanType:                channeldb.SingleFunderTweakless,
+		ChanType:                channeldb.SingleFunderTweaklessBit,
 		IsInitiator:             false,
 		Capacity:                channelCapacity,
 		RemoteCurrentRevocation: aliceCommitPoint,