From 10070ecab7fce2a71425afb90a74f8e3331e9a50 Mon Sep 17 00:00:00 2001
From: "Johan T. Halseth" <johanth@gmail.com>
Date: Fri, 24 Aug 2018 15:31:57 +0200
Subject: [PATCH] lnwallet: make BlockChainIO.GetUTXO take cancel chan

Use quit channels as cancel chan for call to GetUTXO.
---
 contractcourt/channel_arbitrator_test.go | 2 +-
 lnwallet/btcwallet/blockchain.go         | 2 +-
 lnwallet/interface.go                    | 6 ++++--
 lnwallet/wallet.go                       | 2 +-
 mock.go                                  | 2 +-
 routing/notifications_test.go            | 3 ++-
 routing/router.go                        | 1 +
 sweep/test_utils.go                      | 2 +-
 8 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/contractcourt/channel_arbitrator_test.go b/contractcourt/channel_arbitrator_test.go
index e829754f..addf2c50 100644
--- a/contractcourt/channel_arbitrator_test.go
+++ b/contractcourt/channel_arbitrator_test.go
@@ -131,7 +131,7 @@ func (*mockChainIO) GetBestBlock() (*chainhash.Hash, int32, error) {
 }
 
 func (*mockChainIO) GetUtxo(op *wire.OutPoint, _ []byte,
-	heightHint uint32) (*wire.TxOut, error) {
+	heightHint uint32, _ <-chan struct{}) (*wire.TxOut, error) {
 	return nil, nil
 }
 
diff --git a/lnwallet/btcwallet/blockchain.go b/lnwallet/btcwallet/blockchain.go
index 62a72650..ecb5f1a2 100644
--- a/lnwallet/btcwallet/blockchain.go
+++ b/lnwallet/btcwallet/blockchain.go
@@ -38,7 +38,7 @@ func (b *BtcWallet) GetBestBlock() (*chainhash.Hash, int32, error) {
 //
 // This method is a part of the lnwallet.BlockChainIO interface.
 func (b *BtcWallet) GetUtxo(op *wire.OutPoint, pkScript []byte,
-	heightHint uint32) (*wire.TxOut, error) {
+	heightHint uint32, cancel <-chan struct{}) (*wire.TxOut, error) {
 
 	switch backend := b.chain.(type) {
 
diff --git a/lnwallet/interface.go b/lnwallet/interface.go
index d3f53a0e..395da6d1 100644
--- a/lnwallet/interface.go
+++ b/lnwallet/interface.go
@@ -268,8 +268,10 @@ type BlockChainIO interface {
 	// script that the outpoint creates. In the case that the output is in
 	// the UTXO set, then the output corresponding to that output is
 	// returned.  Otherwise, a non-nil error will be returned.
-	GetUtxo(op *wire.OutPoint, pkScript []byte,
-		heightHint uint32) (*wire.TxOut, error)
+	// As for some backends this call can initiate a rescan, the passed
+	// cancel channel can be closed to abort the call.
+	GetUtxo(op *wire.OutPoint, pkScript []byte, heightHint uint32,
+		cancel <-chan struct{}) (*wire.TxOut, error)
 
 	// GetBlockHash returns the hash of the block in the best blockchain
 	// at the given height.
diff --git a/lnwallet/wallet.go b/lnwallet/wallet.go
index ed39a995..27da0004 100644
--- a/lnwallet/wallet.go
+++ b/lnwallet/wallet.go
@@ -974,7 +974,7 @@ func (l *LightningWallet) handleFundingCounterPartySigs(msg *addCounterPartySigs
 			}
 			output, err := l.Cfg.ChainIO.GetUtxo(
 				&txin.PreviousOutPoint,
-				pkScript, 0,
+				pkScript, 0, l.quit,
 			)
 			if output == nil {
 				msg.err <- fmt.Errorf("input to funding tx "+
diff --git a/mock.go b/mock.go
index 00292c8b..657069f4 100644
--- a/mock.go
+++ b/mock.go
@@ -212,7 +212,7 @@ func (m *mockChainIO) GetBestBlock() (*chainhash.Hash, int32, error) {
 }
 
 func (*mockChainIO) GetUtxo(op *wire.OutPoint, _ []byte,
-	heightHint uint32) (*wire.TxOut, error) {
+	heightHint uint32, _ <-chan struct{}) (*wire.TxOut, error) {
 	return nil, nil
 }
 
diff --git a/routing/notifications_test.go b/routing/notifications_test.go
index 3b97a891..548ed51c 100644
--- a/routing/notifications_test.go
+++ b/routing/notifications_test.go
@@ -181,7 +181,8 @@ func (m *mockChain) addUtxo(op wire.OutPoint, out *wire.TxOut) {
 	m.utxos[op] = *out
 	m.Unlock()
 }
-func (m *mockChain) GetUtxo(op *wire.OutPoint, _ []byte, _ uint32) (*wire.TxOut, error) {
+func (m *mockChain) GetUtxo(op *wire.OutPoint, _ []byte, _ uint32,
+	_ <-chan struct{}) (*wire.TxOut, error) {
 	m.RLock()
 	defer m.RUnlock()
 
diff --git a/routing/router.go b/routing/router.go
index 96f503ab..acefcd93 100644
--- a/routing/router.go
+++ b/routing/router.go
@@ -1113,6 +1113,7 @@ func (r *ChannelRouter) processUpdate(msg interface{}) error {
 		// been closed so we'll ignore it.
 		chanUtxo, err := r.cfg.Chain.GetUtxo(
 			fundingPoint, fundingPkScript, channelID.BlockHeight,
+			r.quit,
 		)
 		if err != nil {
 			r.rejectMtx.Lock()
diff --git a/sweep/test_utils.go b/sweep/test_utils.go
index 0362741a..c221449e 100644
--- a/sweep/test_utils.go
+++ b/sweep/test_utils.go
@@ -245,7 +245,7 @@ func (m *mockChainIO) GetBestBlock() (*chainhash.Hash, int32, error) {
 }
 
 func (m *mockChainIO) GetUtxo(op *wire.OutPoint, pkScript []byte,
-	heightHint uint32) (*wire.TxOut, error) {
+	heightHint uint32, _ <-chan struct{}) (*wire.TxOut, error) {
 
 	return nil, nil
 }