fix: rename wiretap to tracer

To avoid... confusion and angst. This also removes the option to
_disable_ it, because there's really no need (not safe to do at runtime
anyways).


This commit was moved from ipfs/go-bitswap@d3c024e

bitswap/bitswap.go

@@ -335,7 +335,7 @@ type Bitswap struct {
 	sendTimeHistogram metrics.Histogram
 
 	// External statistics interface
-	wiretap WireTap
+	tracer Tracer
 
 	// the SessionManager routes requests to interested sessions
 	sm *bssm.SessionManager
@@ -527,8 +527,8 @@ func (bs *Bitswap) ReceiveMessage(ctx context.Context, p peer.ID, incoming bsmsg
 	// TODO: this is bad, and could be easily abused.
 	// Should only track *useful* messages in ledger
 
-	if bs.wiretap != nil {
-		bs.wiretap.MessageReceived(p, incoming)
+	if bs.tracer != nil {
+		bs.tracer.MessageReceived(p, incoming)
 	}
 
 	iblocks := incoming.Blocks()

bitswap/bitswap_test.go

@@ -870,29 +870,29 @@ type logItem struct {
 	pid peer.ID
 	msg bsmsg.BitSwapMessage
 }
-type mockWireTap struct {
+type mockTracer struct {
 	mu  sync.Mutex
 	log []logItem
 }
 
-func (m *mockWireTap) MessageReceived(p peer.ID, msg bsmsg.BitSwapMessage) {
+func (m *mockTracer) MessageReceived(p peer.ID, msg bsmsg.BitSwapMessage) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	m.log = append(m.log, logItem{'r', p, msg})
 }
-func (m *mockWireTap) MessageSent(p peer.ID, msg bsmsg.BitSwapMessage) {
+func (m *mockTracer) MessageSent(p peer.ID, msg bsmsg.BitSwapMessage) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	m.log = append(m.log, logItem{'s', p, msg})
 }
 
-func (m *mockWireTap) getLog() []logItem {
+func (m *mockTracer) getLog() []logItem {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	return m.log[:len(m.log):len(m.log)]
 }
 
-func TestWireTap(t *testing.T) {
+func TestTracer(t *testing.T) {
 	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
 	ig := testinstance.NewTestInstanceGenerator(net, nil, nil)
 	defer ig.Close()
@@ -901,9 +901,9 @@ func TestWireTap(t *testing.T) {
 	instances := ig.Instances(3)
 	blocks := bg.Blocks(2)
 
-	// Install WireTap
-	wiretap := new(mockWireTap)
-	bitswap.EnableWireTap(wiretap)(instances[0].Exchange)
+	// Install Tracer
+	wiretap := new(mockTracer)
+	bitswap.WithTracer(wiretap)(instances[0].Exchange)
 
 	// First peer has block
 	err := instances[0].Exchange.HasBlock(blocks[0])
@@ -937,9 +937,9 @@ func TestWireTap(t *testing.T) {
 
 	log := wiretap.getLog()
 
-	// After communication, 3 messages should be logged via WireTap
+	// After communication, 3 messages should be logged via Tracer
 	if l := len(log); l != 3 {
-		t.Fatal("expected 3 items logged via WireTap, found", l)
+		t.Fatal("expected 3 items logged via Tracer, found", l)
 	}
 
 	// Received: 'Have'
@@ -988,7 +988,7 @@ func TestWireTap(t *testing.T) {
 	}
 
 	// After disabling WireTap, no new messages are logged
-	bitswap.DisableWireTap()(instances[0].Exchange)
+	bitswap.WithTracer(nil)(instances[0].Exchange)
 
 	err = instances[0].Exchange.HasBlock(blocks[1])
 	if err != nil {

bitswap/tracer.go

@@ -0,0 +1,20 @@
+package bitswap
+
+import (
+	bsmsg "github.com/ipfs/go-bitswap/message"
+	peer "github.com/libp2p/go-libp2p-core/peer"
+)
+
+// Tracer provides methods to access all messages sent and received by Bitswap.
+// This interface can be used to implement various statistics (this is original intent).
+type Tracer interface {
+	MessageReceived(peer.ID, bsmsg.BitSwapMessage)
+	MessageSent(peer.ID, bsmsg.BitSwapMessage)
+}
+
+// Configures Bitswap to use given tracer.
+func WithTracer(tap Tracer) Option {
+	return func(bs *Bitswap) {
+		bs.tracer = tap
+	}
+}

bitswap/workers.go

@@ -56,8 +56,8 @@ func (bs *Bitswap) taskWorker(ctx context.Context, id int) {
 				// Ideally, yes. But we'd need some way to trigger a retry and/or drop
 				// the peer.
 				bs.engine.MessageSent(envelope.Peer, envelope.Message)
-				if bs.wiretap != nil {
-					bs.wiretap.MessageSent(envelope.Peer, envelope.Message)
+				if bs.tracer != nil {
+					bs.tracer.MessageSent(envelope.Peer, envelope.Message)
 				}
 				bs.sendBlocks(ctx, envelope)