multi: update to latest BitcoindClient interface

In this commit, we introduce a nice optimization with regards to lnd's
interaction with a bitcoind backend. Within lnd, we currently have three
different subsystems responsible for watching the chain: chainntnfs,
lnwallet, and routing/chainview. Each of these subsystems has an active
RPC and ZMQ connection to the underlying bitcoind node. This would incur
a toll on the underlying bitcoind node and would cause us to miss ZMQ
events, which are crucial to lnd. We remedy this issue by sharing the
same connection to a bitcoind node between the different clients within
lnd.

routing/chainview/bitcoind.go

@@ -9,9 +9,7 @@ import (
 	"time"
 
 	"github.com/btcsuite/btcd/btcjson"
-	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
-	"github.com/btcsuite/btcd/rpcclient"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcwallet/chain"
 	"github.com/btcsuite/btcwallet/wtxmgr"
@@ -63,9 +61,8 @@ var _ FilteredChainView = (*BitcoindFilteredChainView)(nil)
 
 // NewBitcoindFilteredChainView creates a new instance of a FilteredChainView
 // from RPC credentials and a ZMQ socket address for a bitcoind instance.
-func NewBitcoindFilteredChainView(config rpcclient.ConnConfig,
-	zmqConnect string, params chaincfg.Params) (*BitcoindFilteredChainView,
-	error) {
+func NewBitcoindFilteredChainView(
+	chainConn *chain.BitcoindConn) *BitcoindFilteredChainView {
 
 	chainView := &BitcoindFilteredChainView{
 		chainFilter:     make(map[wire.OutPoint]struct{}),
@@ -74,16 +71,10 @@ func NewBitcoindFilteredChainView(config rpcclient.ConnConfig,
 		quit:            make(chan struct{}),
 	}
 
-	chainConn, err := chain.NewBitcoindClient(&params, config.Host,
-		config.User, config.Pass, zmqConnect, 100*time.Millisecond)
-	if err != nil {
-		return nil, err
-	}
-	chainView.chainClient = chainConn
-
+	chainView.chainClient = chainConn.NewBitcoindClient(time.Unix(0, 0))
 	chainView.blockQueue = newBlockEventQueue()
 
-	return chainView, nil
+	return chainView
 }
 
 // Start starts all goroutines necessary for normal operation.
@@ -325,9 +316,11 @@ func (b *BitcoindFilteredChainView) chainFilterer() {
 			// will cause all following notifications from and
 			// calls to it return blocks filtered with the new
 			// filter.
-			b.chainClient.LoadTxFilter(
-				false, update.newUtxos,
-			)
+			err := b.chainClient.LoadTxFilter(false, update.newUtxos)
+			if err != nil {
+				log.Errorf("Unable to update filter: %v", err)
+				continue
+			}
 
 			// All blocks gotten after we loaded the filter will
 			// have the filter applied, but we will need to rescan

routing/chainview/interface_test.go

@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"github.com/btcsuite/btcd/btcec"
+	"github.com/btcsuite/btcd/btcjson"
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/integration/rpctest"
@@ -20,12 +21,12 @@ import (
 	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
-	"github.com/lightninglabs/neutrino"
-	"github.com/lightningnetwork/lnd/channeldb"
-	"github.com/ltcsuite/ltcd/btcjson"
-
+	"github.com/btcsuite/btcwallet/chain"
 	"github.com/btcsuite/btcwallet/walletdb"
 	_ "github.com/btcsuite/btcwallet/walletdb/bdb" // Required to register the boltdb walletdb implementation.
+
+	"github.com/lightninglabs/neutrino"
+	"github.com/lightningnetwork/lnd/channeldb"
 )
 
 var (
@@ -776,7 +777,8 @@ var interfaceImpls = []struct {
 			if err != nil {
 				return nil, nil, err
 			}
-			zmqPath := "ipc:///" + tempBitcoindDir + "/weks.socket"
+			zmqBlockHost := "ipc:///" + tempBitcoindDir + "/blocks.socket"
+			zmqTxHost := "ipc:///" + tempBitcoindDir + "/tx.socket"
 			cleanUp1 := func() {
 				os.RemoveAll(tempBitcoindDir)
 			}
@@ -792,8 +794,8 @@ var interfaceImpls = []struct {
 					"220110063096c221be9933c82d38e1",
 				fmt.Sprintf("-rpcport=%d", rpcPort),
 				"-disablewallet",
-				"-zmqpubrawblock="+zmqPath,
-				"-zmqpubrawtx="+zmqPath,
+				"-zmqpubrawblock="+zmqBlockHost,
+				"-zmqpubrawtx="+zmqTxHost,
 			)
 			err = bitcoind.Start()
 			if err != nil {
@@ -809,25 +811,30 @@ var interfaceImpls = []struct {
 			// Wait for the bitcoind instance to start up.
 			time.Sleep(time.Second)
 
-			// Start the FilteredChainView implementation instance.
-			config := rpcclient.ConnConfig{
-				Host: fmt.Sprintf(
-					"127.0.0.1:%d", rpcPort),
-				User:                 "weks",
-				Pass:                 "weks",
-				DisableAutoReconnect: false,
-				DisableConnectOnNew:  true,
-				DisableTLS:           true,
-				HTTPPostMode:         true,
+			host := fmt.Sprintf("127.0.0.1:%d", rpcPort)
+			chainConn, err := chain.NewBitcoindConn(
+				&chaincfg.RegressionNetParams, host, "weks",
+				"weks", zmqBlockHost, zmqTxHost,
+				100*time.Millisecond,
+			)
+			if err != nil {
+				return cleanUp2, nil, fmt.Errorf("unable to "+
+					"establish connection to bitcoind: %v",
+					err)
+			}
+			if err := chainConn.Start(); err != nil {
+				return cleanUp2, nil, fmt.Errorf("unable to "+
+					"establish connection to bitcoind: %v",
+					err)
+			}
+			cleanUp3 := func() {
+				chainConn.Stop()
+				cleanUp2()
 			}
 
-			chainView, err := NewBitcoindFilteredChainView(config,
-				zmqPath, chaincfg.RegressionNetParams)
-			if err != nil {
-				cleanUp2()
-				return nil, nil, err
-			}
-			return cleanUp2, chainView, nil
+			chainView := NewBitcoindFilteredChainView(chainConn)
+
+			return cleanUp3, chainView, nil
 		},
 	},
 	{