chainntnfs: add height hint caches to chain notifiers

chainntnfs/btcdnotify/btcd.go

@@ -83,6 +83,16 @@ type BtcdNotifier struct {
 	chainUpdates *chainntnfs.ConcurrentQueue
 	txUpdates    *chainntnfs.ConcurrentQueue
 
+	// spendHintCache is a cache used to query and update the latest height
+	// hints for an outpoint. Each height hint represents the earliest
+	// height at which the outpoint could have been spent within the chain.
+	spendHintCache chainntnfs.SpendHintCache
+
+	// confirmHintCache is a cache used to query the latest height hints for
+	// a transaction. Each height hint represents the earliest height at
+	// which the transaction could have confirmed within the chain.
+	confirmHintCache chainntnfs.ConfirmHintCache
+
 	wg   sync.WaitGroup
 	quit chan struct{}
 }
@@ -93,7 +103,9 @@ var _ chainntnfs.ChainNotifier = (*BtcdNotifier)(nil)
 // New returns a new BtcdNotifier instance. This function assumes the btcd node
 // detailed in the passed configuration is already running, and willing to
 // accept new websockets clients.
-func New(config *rpcclient.ConnConfig) (*BtcdNotifier, error) {
+func New(config *rpcclient.ConnConfig, spendHintCache chainntnfs.SpendHintCache,
+	confirmHintCache chainntnfs.ConfirmHintCache) (*BtcdNotifier, error) {
+
 	notifier := &BtcdNotifier{
 		notificationCancels:  make(chan interface{}),
 		notificationRegistry: make(chan interface{}),
@@ -105,6 +117,9 @@ func New(config *rpcclient.ConnConfig) (*BtcdNotifier, error) {
 		chainUpdates: chainntnfs.NewConcurrentQueue(10),
 		txUpdates:    chainntnfs.NewConcurrentQueue(10),
 
+		spendHintCache:   spendHintCache,
+		confirmHintCache: confirmHintCache,
+
 		quit: make(chan struct{}),
 	}
 
@@ -150,7 +165,8 @@ func (b *BtcdNotifier) Start() error {
 	}
 
 	b.txConfNotifier = chainntnfs.NewTxConfNotifier(
-		uint32(currentHeight), reorgSafetyLimit)
+		uint32(currentHeight), reorgSafetyLimit, b.confirmHintCache,
+	)
 
 	b.bestBlock = chainntnfs.BlockEpoch{
 		Height: currentHeight,

chainntnfs/btcdnotify/btcd_debug.go

@@ -28,7 +28,8 @@ func (b *BtcdNotifier) UnsafeStart(bestHeight int32, bestHash *chainhash.Hash,
 	}
 
 	b.txConfNotifier = chainntnfs.NewTxConfNotifier(
-		uint32(bestHeight), reorgSafetyLimit)
+		uint32(bestHeight), reorgSafetyLimit, b.confirmHintCache,
+	)
 
 	b.chainUpdates.Start()
 	b.txUpdates.Start()

chainntnfs/btcdnotify/driver.go

@@ -1,6 +1,7 @@
 package btcdnotify
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/btcsuite/btcd/rpcclient"
@@ -10,18 +11,30 @@ import (
 // createNewNotifier creates a new instance of the ChainNotifier interface
 // implemented by BtcdNotifier.
 func createNewNotifier(args ...interface{}) (chainntnfs.ChainNotifier, error) {
-	if len(args) != 1 {
-		return nil, fmt.Errorf("incorrect number of arguments to .New(...), "+
-			"expected 1, instead passed %v", len(args))
+	if len(args) != 3 {
+		return nil, fmt.Errorf("incorrect number of arguments to "+
+			".New(...), expected 2, instead passed %v", len(args))
 	}
 
 	config, ok := args[0].(*rpcclient.ConnConfig)
 	if !ok {
-		return nil, fmt.Errorf("first argument to btcdnotifier.New is " +
-			"incorrect, expected a *rpcclient.ConnConfig")
+		return nil, errors.New("first argument to btcdnotifier.New " +
+			"is incorrect, expected a *rpcclient.ConnConfig")
 	}
 
-	return New(config)
+	spendHintCache, ok := args[1].(chainntnfs.SpendHintCache)
+	if !ok {
+		return nil, errors.New("second argument to btcdnotifier.New " +
+			"is incorrect, expected a chainntnfs.SpendHintCache")
+	}
+
+	confirmHintCache, ok := args[2].(chainntnfs.ConfirmHintCache)
+	if !ok {
+		return nil, errors.New("third argument to btcdnotifier.New " +
+			"is incorrect, expected a chainntnfs.ConfirmHintCache")
+	}
+
+	return New(config, spendHintCache, confirmHintCache)
 }
 
 // init registers a driver for the BtcdNotifier concrete implementation of the