Expose torrent Peer status updates

callbacks.go

@@ -34,6 +34,10 @@ type Callbacks struct {
 	// handshake has not yet occurred. This is a good time to alter the supported extension
 	// protocols.
 	PeerConnAdded []func(*PeerConn)
+
+	// Sends status event updates. Useful to inform the user of specific events as they happen,
+	// for logging or to action on.
+	StatusUpdated []func(StatusUpdatedEvent)
 }
 
 type ReceivedUsefulDataEvent = PeerMessageEvent
@@ -54,3 +58,23 @@ type PeerConnReadExtensionMessageEvent struct {
 	ExtensionNumber pp.ExtensionNumber
 	Payload         []byte
 }
+
+type StatusUpdatedEvent struct {
+	Event StatusEvent `json:"event"`
+	Error error       `json:"error"`
+	// The following fields may or may not be populated depending on the event.
+	PeerId   PeerID `json:"peer_id"`
+	Url      string `json:"url"`
+	InfoHash string `json:"info_hash"`
+}
+
+type StatusEvent string
+
+const (
+	PeerConnected             StatusEvent = "peer_connected"
+	PeerDisconnected          StatusEvent = "peer_disconnected"
+	TrackerConnected          StatusEvent = "tracker_connected"
+	TrackerDisconnected       StatusEvent = "tracker_disconnected"
+	TrackerAnnounceSuccessful StatusEvent = "tracker_announce_successful"
+	TrackerAnnounceError      StatusEvent = "tracker_announce_error"
+)

client-peerconn_test.go

@@ -0,0 +1,188 @@
+package torrent
+
+import (
+	"io"
+	"os"
+	"testing"
+	"testing/iotest"
+
+	"github.com/anacrolix/missinggo/v2"
+	"github.com/anacrolix/missinggo/v2/bitmap"
+	"github.com/anacrolix/torrent/internal/testutil"
+	"github.com/frankban/quicktest"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/time/rate"
+)
+
+func TestPeerConnEstablished(t *testing.T) {
+	var expectedPeerId PeerID
+	missinggo.CopyExact(&expectedPeerId, "12345123451234512345")
+
+	gotPeerConnectedEvt := false
+	gotPeerDisconnectedEvt := false
+	ps := testClientTransferParams{
+		ConfigureSeeder: ConfigureClient{
+			Config: func(cfg *ClientConfig) {
+				cfg.PeerID = "12345123451234512345"
+			},
+		},
+		ConfigureLeecher: ConfigureClient{
+			Config: func(cfg *ClientConfig) {
+				// cfg.DisableUTP = true
+				cfg.DisableTCP = true
+				cfg.Debug = false
+				cfg.DisableTrackers = true
+				cfg.EstablishedConnsPerTorrent = 1
+				cfg.Callbacks.StatusUpdated = append(cfg.Callbacks.StatusUpdated,
+					func(e StatusUpdatedEvent) {
+						if e.Event == PeerConnected {
+							gotPeerConnectedEvt = true
+							require.Equal(t, expectedPeerId, e.PeerId)
+							require.NoError(t, e.Error)
+						}
+					},
+					func(e StatusUpdatedEvent) {
+						if e.Event == PeerDisconnected {
+							gotPeerDisconnectedEvt = true
+							require.Equal(t, expectedPeerId, e.PeerId)
+							require.NoError(t, e.Error)
+						}
+					},
+				)
+			},
+		},
+	}
+
+	testClientTransfer(t, ps)
+	// double check that the callbacks were called
+	require.True(t, gotPeerConnectedEvt)
+	require.True(t, gotPeerDisconnectedEvt)
+}
+
+type ConfigureClient struct {
+	Config func(cfg *ClientConfig)
+	Client func(cl *Client)
+}
+
+type testClientTransferParams struct {
+	SeederUploadRateLimiter    *rate.Limiter
+	LeecherDownloadRateLimiter *rate.Limiter
+	ConfigureSeeder            ConfigureClient
+	ConfigureLeecher           ConfigureClient
+
+	LeecherStartsWithoutMetadata bool
+}
+
+// Simplified version of testClientTransfer found in test/leecher-storage.go.
+// Could not import and reuse that function due to circular dependencies between modules.
+func testClientTransfer(t *testing.T, ps testClientTransferParams) {
+	greetingTempDir, mi := testutil.GreetingTestTorrent()
+	defer os.RemoveAll(greetingTempDir)
+	// Create seeder and a Torrent.
+	cfg := TestingConfig(t)
+	cfg.Seed = true
+	// Some test instances don't like this being on, even when there's no cache involved.
+	cfg.DropMutuallyCompletePeers = false
+	if ps.SeederUploadRateLimiter != nil {
+		cfg.UploadRateLimiter = ps.SeederUploadRateLimiter
+	}
+	cfg.DataDir = greetingTempDir
+	if ps.ConfigureSeeder.Config != nil {
+		ps.ConfigureSeeder.Config(cfg)
+	}
+	seeder, err := NewClient(cfg)
+	require.NoError(t, err)
+	if ps.ConfigureSeeder.Client != nil {
+		ps.ConfigureSeeder.Client(seeder)
+	}
+	seederTorrent, _, _ := seeder.AddTorrentSpec(TorrentSpecFromMetaInfo(mi))
+	defer seeder.Close()
+	<-seederTorrent.Complete().On()
+
+	// Create leecher and a Torrent.
+	leecherDataDir := t.TempDir()
+	cfg = TestingConfig(t)
+	// See the seeder client config comment.
+	cfg.DropMutuallyCompletePeers = false
+	cfg.DataDir = leecherDataDir
+	if ps.LeecherDownloadRateLimiter != nil {
+		cfg.DownloadRateLimiter = ps.LeecherDownloadRateLimiter
+	}
+	cfg.Seed = false
+	if ps.ConfigureLeecher.Config != nil {
+		ps.ConfigureLeecher.Config(cfg)
+	}
+	leecher, err := NewClient(cfg)
+	require.NoError(t, err)
+	defer leecher.Close()
+	if ps.ConfigureLeecher.Client != nil {
+		ps.ConfigureLeecher.Client(leecher)
+	}
+	leecherTorrent, new, err := leecher.AddTorrentSpec(func() (ret *TorrentSpec) {
+		ret = TorrentSpecFromMetaInfo(mi)
+		ret.ChunkSize = 2
+		if ps.LeecherStartsWithoutMetadata {
+			ret.InfoBytes = nil
+		}
+		return
+	}())
+	require.NoError(t, err)
+	assert.False(t, leecherTorrent.Complete().Bool())
+	assert.True(t, new)
+
+	added := leecherTorrent.AddClientPeer(seeder)
+	assert.False(t, leecherTorrent.Seeding())
+	// The leecher will use peers immediately if it doesn't have the metadata. Otherwise, they
+	// should be sitting idle until we demand data.
+	if !ps.LeecherStartsWithoutMetadata {
+		assert.EqualValues(t, added, leecherTorrent.Stats().PendingPeers)
+	}
+	if ps.LeecherStartsWithoutMetadata {
+		<-leecherTorrent.GotInfo()
+	}
+	r := leecherTorrent.NewReader()
+	defer r.Close()
+	go leecherTorrent.SetInfoBytes(mi.InfoBytes)
+
+	assertReadAllGreeting(t, r)
+	<-leecherTorrent.Complete().On()
+	assert.NotEmpty(t, seederTorrent.PeerConns())
+	leecherPeerConns := leecherTorrent.PeerConns()
+	if cfg.DropMutuallyCompletePeers {
+		// I don't think we can assume it will be empty already, due to timing.
+		// assert.Empty(t, leecherPeerConns)
+	} else {
+		assert.NotEmpty(t, leecherPeerConns)
+	}
+	foundSeeder := false
+	for _, pc := range leecherPeerConns {
+		completed := pc.PeerPieces().GetCardinality()
+		t.Logf("peer conn %v has %v completed pieces", pc, completed)
+		if completed == bitmap.BitRange(leecherTorrent.Info().NumPieces()) {
+			foundSeeder = true
+		}
+	}
+	if !foundSeeder {
+		t.Errorf("didn't find seeder amongst leecher peer conns")
+	}
+
+	seederStats := seederTorrent.Stats()
+	assert.True(t, 13 <= seederStats.BytesWrittenData.Int64())
+	assert.True(t, 8 <= seederStats.ChunksWritten.Int64())
+
+	leecherStats := leecherTorrent.Stats()
+	assert.True(t, 13 <= leecherStats.BytesReadData.Int64())
+	assert.True(t, 8 <= leecherStats.ChunksRead.Int64())
+
+	// Try reading through again for the cases where the torrent data size
+	// exceeds the size of the cache.
+	assertReadAllGreeting(t, r)
+}
+
+func assertReadAllGreeting(t *testing.T, r io.ReadSeeker) {
+	pos, err := r.Seek(0, io.SeekStart)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 0, pos)
+	quicktest.Check(t, iotest.TestReader(r, []byte(testutil.GreetingFileContents)), quicktest.IsNil)
+}