graphdb: plug in the cache to sqlstore

In this commit, we add publicNodeCache into the sqlstore. We also
add the necessary config for initializing the cache.

Signed-off-by: Abdullahi Yunus <[email protected]>

Author: Abdulkbk

graph/db/options.go

@@ -13,6 +13,11 @@ const (
 	// around 40MB.
 	DefaultChannelCacheSize = 20000
 
+	// DefaultPublicNodeCacheSize is the default number of node public
+	// status entries to cache. With 15k nodes, this produces a cache of
+	// around 500KB.
+	DefaultPublicNodeCacheSize = 15000
+
 	// DefaultPreAllocCacheNumNodes is the default number of channels we
 	// assume for mainnet for pre-allocating the graph cache. As of
 	// September 2021, there currently are 14k nodes in a strictly pruned
@@ -125,6 +130,10 @@ type StoreOptions struct {
 	// channel cache.
 	ChannelCacheSize int
 
+	// PublicNodeCacheSize is the maximum number of node public status
+	// entries to hold in the cache.
+	PublicNodeCacheSize int
+
 	// BatchCommitInterval is the maximum duration the batch schedulers will
 	// wait before attempting to commit a pending set of updates.
 	BatchCommitInterval time.Duration
@@ -138,9 +147,10 @@ type StoreOptions struct {
 // DefaultOptions returns a StoreOptions populated with default values.
 func DefaultOptions() *StoreOptions {
 	return &StoreOptions{
-		RejectCacheSize:  DefaultRejectCacheSize,
-		ChannelCacheSize: DefaultChannelCacheSize,
-		NoMigration:      false,
+		RejectCacheSize:     DefaultRejectCacheSize,
+		ChannelCacheSize:    DefaultChannelCacheSize,
+		PublicNodeCacheSize: DefaultPublicNodeCacheSize,
+		NoMigration:         false,
 	}
 }
 
@@ -169,3 +179,5 @@ func WithBatchCommitInterval(interval time.Duration) StoreOptionModifier {
 		o.BatchCommitInterval = interval
 	}
 }
+
+// Todo(abdulkbk) consider adding WithPublicNodeCacheSize.

graph/db/sql_store.go

@@ -20,6 +20,7 @@ import (
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
+	"github.com/lightninglabs/neutrino/cache/lru"
 	"github.com/lightningnetwork/lnd/aliasmgr"
 	"github.com/lightningnetwork/lnd/batch"
 	"github.com/lightningnetwork/lnd/fn/v2"
@@ -181,12 +182,14 @@ type SQLStore struct {
 	cfg *SQLStoreConfig
 	db  BatchedSQLQueries
 
-	// cacheMu guards all caches (rejectCache and chanCache). If
-	// this mutex will be acquired at the same time as the DB mutex then
-	// the cacheMu MUST be acquired first to prevent deadlock.
-	cacheMu     sync.RWMutex
-	rejectCache *rejectCache
-	chanCache   *channelCache
+	// cacheMu guards all caches (rejectCache, chanCache, and
+	// publicNodeCache). If this mutex will be acquired at the same time as
+	// the DB mutex then the cacheMu MUST be acquired first to prevent
+	// deadlock.
+	cacheMu         sync.RWMutex
+	rejectCache     *rejectCache
+	chanCache       *channelCache
+	publicNodeCache *lru.Cache[[33]byte, *cachedPublicNode]
 
 	chanScheduler batch.Scheduler[SQLQueries]
 	nodeScheduler batch.Scheduler[SQLQueries]
@@ -241,7 +244,10 @@ func NewSQLStore(cfg *SQLStoreConfig, db BatchedSQLQueries,
 		db:          db,
 		rejectCache: newRejectCache(opts.RejectCacheSize),
 		chanCache:   newChannelCache(opts.ChannelCacheSize),
-		srcNodes:    make(map[ProtocolVersion]*srcNodeInfo),
+		publicNodeCache: lru.NewCache[[33]byte, *cachedPublicNode](
+			uint64(opts.PublicNodeCacheSize),
+		),
+		srcNodes: make(map[ProtocolVersion]*srcNodeInfo),
 	}
 
 	s.chanScheduler = batch.NewTimeScheduler(