Use cache in topic pool (#955)

It must have slipped when i moved significant chunk of logic
from peer pool to topic pool and because of the != nil protection
this bug was missed

geth/peers/cache_test.go

@@ -5,19 +5,24 @@ import (
 	"testing"
 
 	"github.com/ethereum/go-ethereum/p2p/discv5"
-	"github.com/status-im/status-go/geth/db"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/syndtr/goleveldb/leveldb"
+	"github.com/syndtr/goleveldb/leveldb/storage"
 )
 
-func TestPeersRange(t *testing.T) {
-	rootDB, err := db.Create("", "status-peers-test")
-	require.NoError(t, err)
-	defer func() {
-		assert.NoError(t, rootDB.Close())
-	}()
+// newInMemoryCache creates a cache for tests
+func newInMemoryCache() (*Cache, error) {
+	memdb, err := leveldb.Open(storage.NewMemStorage(), nil)
+	if err != nil {
+		return nil, err
+	}
+	return NewCache(memdb), nil
+}
 
-	peersDB := Cache{db: rootDB}
+func TestPeersRange(t *testing.T) {
+	peersDB, err := newInMemoryCache()
+	require.NoError(t, err)
 	topic := discv5.Topic("test")
 	peers := [3]*discv5.Node{
 		discv5.NewNode(discv5.NodeID{3}, net.IPv4(100, 100, 0, 3), 32311, 32311),

geth/peers/peerpool.go

@@ -116,7 +116,7 @@ func (p *PeerPool) Start(server *p2p.Server) error {
 	// collect topics and start searching for nodes
 	p.topics = make([]*TopicPool, 0, len(p.config))
 	for topic, limits := range p.config {
-		topicPool := NewTopicPool(topic, limits, p.opts.SlowSync, p.opts.FastSync)
+		topicPool := NewTopicPool(topic, limits, p.opts.SlowSync, p.opts.FastSync, p.cache)
 		if err := topicPool.StartSearch(server); err != nil {
 			return err
 		}

geth/peers/peerpool_test.go

@@ -133,7 +133,9 @@ func (s *PeerPoolSimulationSuite) TestSingleTopicDiscoveryWithFailover() {
 		topic: params.NewLimits(1, 1), // limits are chosen for simplicity of the simulation
 	}
 	peerPoolOpts := &Options{100 * time.Millisecond, 100 * time.Millisecond, 0, true}
-	peerPool := NewPeerPool(config, nil, peerPoolOpts)
+	cache, err := newInMemoryCache()
+	s.Require().NoError(err)
+	peerPool := NewPeerPool(config, cache, peerPoolOpts)
 	register := NewRegister(topic)
 	s.Require().NoError(register.Start(s.peers[0]))
 	// need to wait for topic to get registered, discv5 can query same node
@@ -173,6 +175,11 @@ func (s *PeerPoolSimulationSuite) TestSingleTopicDiscoveryWithFailover() {
 	s.Require().Equal(signal.EventDiscoverySummary, s.getPoolEvent(poolEvents))
 	summary = <-summaries
 	s.Len(summary, 1)
+
+	// verify that we are actually using cache
+	cachedPeers := peerPool.cache.GetPeersRange(topic, 1)
+	s.Len(cachedPeers, 1)
+	s.Equal(s.peers[2].Self().ID, discover.NodeID(cachedPeers[0].ID))
 }
 
 // TestPeerPoolMaxPeersOverflow verifies that following scenario will not occur:

geth/peers/topicpool.go

@@ -15,7 +15,7 @@ import (
 )
 
 // NewTopicPool returns instance of TopicPool
-func NewTopicPool(topic discv5.Topic, limits params.Limits, slowMode, fastMode time.Duration) *TopicPool {
+func NewTopicPool(topic discv5.Topic, limits params.Limits, slowMode, fastMode time.Duration, cache *Cache) *TopicPool {
 	pool := TopicPool{
 		topic:           topic,
 		limits:          limits,
@@ -25,6 +25,7 @@ func NewTopicPool(topic discv5.Topic, limits params.Limits, slowMode, fastMode t
 		peerPool:        make(map[discv5.NodeID]*peerInfoItem),
 		peerPoolQueue:   make(peerPriorityQueue, 0),
 		connectedPeers:  make(map[discv5.NodeID]*peerInfo),
+		cache:           cache,
 	}
 
 	heap.Init(&pool.peerPoolQueue)
@@ -198,10 +199,8 @@ func (t *TopicPool) ConfirmAdded(server *p2p.Server, nodeID discover.NodeID) {
 
 	// established connection means that the node
 	// is a viable candidate for a connection and can be cached
-	if t.cache != nil {
-		if err := t.cache.AddPeer(peer.node, t.topic); err != nil {
-			log.Error("failed to persist a peer", "error", err)
-		}
+	if err := t.cache.AddPeer(peer.node, t.topic); err != nil {
+		log.Error("failed to persist a peer", "error", err)
 	}
 
 	// if the upper limit is already reached, drop this peer
@@ -256,10 +255,8 @@ func (t *TopicPool) ConfirmDropped(server *p2p.Server, nodeID discover.NodeID) b
 	t.removeServerPeer(server, peer)
 
 	delete(t.connectedPeers, discV5NodeID)
-	if t.cache != nil {
-		if err := t.cache.RemovePeer(discV5NodeID, t.topic); err != nil {
-			log.Error("failed to remove peer from cache", "error", err)
-		}
+	if err := t.cache.RemovePeer(discV5NodeID, t.topic); err != nil {
+		log.Error("failed to remove peer from cache", "error", err)
 	}
 
 	// As we removed a peer, update a sync strategy if needed.
@@ -312,11 +309,9 @@ func (t *TopicPool) StartSearch(server *p2p.Server) error {
 	found := make(chan *discv5.Node, 5) // 5 reasonable number for concurrently found nodes
 	lookup := make(chan bool, 10)       // sufficiently buffered channel, just prevents blocking because of lookup
 
-	if t.cache != nil {
-		for _, peer := range t.cache.GetPeersRange(t.topic, 5) {
-			log.Debug("adding a peer from cache", "peer", peer)
-			found <- peer
-		}
+	for _, peer := range t.cache.GetPeersRange(t.topic, 5) {
+		log.Debug("adding a peer from cache", "peer", peer)
+		found <- peer
 	}
 
 	t.discWG.Add(1)

geth/peers/topicpool_test.go

@@ -39,7 +39,9 @@ func (s *TopicPoolSuite) SetupTest() {
 	s.Require().NoError(s.peer.Start())
 	topic := discv5.Topic("cap=cap1")
 	limits := params.NewLimits(1, 2)
-	s.topicPool = NewTopicPool(topic, limits, 100*time.Millisecond, 200*time.Millisecond)
+	cache, err := newInMemoryCache()
+	s.Require().NoError(err)
+	s.topicPool = NewTopicPool(topic, limits, 100*time.Millisecond, 200*time.Millisecond, cache)
 	s.topicPool.running = 1
 	// This is a buffered channel to simplify testing.
 	// If your test generates more than 10 mode changes,