feat: Add dead callback for conn

telegram/client.go

@@ -89,6 +89,7 @@ type Client struct {
 	// Connection factory fields.
 	create       connConstructor        // immutable
 	resolver     dcs.Resolver           // immutable
+	onDead       func()                 // immutable
 	connBackoff  func() backoff.BackOff // immutable
 	defaultMode  manager.ConnMode       // immutable
 	connsCounter atomic.Int64
@@ -159,6 +160,7 @@ func NewClient(appID int, appHash string, opt Options) *Client {
 		resolver:         opt.Resolver,
 		defaultMode:      mode,
 		connBackoff:      opt.ReconnectionBackoff,
+		onDead:           opt.OnDead,
 		clock:            opt.Clock,
 		device:           opt.Device,
 		migrationTimeout: opt.MigrationTimeout,

telegram/conn_builder.go

@@ -68,13 +68,14 @@ func (c *Client) primaryDC(dc int) mtproto.Dialer {
 }
 
 func (c *Client) createPrimaryConn(setup manager.SetupCallback) pool.Conn {
-	return c.createConn(0, c.defaultMode, setup)
+	return c.createConn(0, c.defaultMode, setup, c.onDead)
 }
 
 func (c *Client) createConn(
 	id int64,
 	mode manager.ConnMode,
 	setup manager.SetupCallback,
+	onDead func(),
 ) pool.Conn {
 	opts, s := c.session.Options(c.opts)
 	opts.Logger = c.log.Named("conn").With(
@@ -90,6 +91,7 @@ func (c *Client) createConn(
 			Device:  c.device,
 			Handler: c.asHandler(),
 			Setup:   setup,
+			OnDead:  onDead,
 		},
 	)
 }

telegram/internal/manager/conn.go

@@ -53,6 +53,9 @@ type Conn struct {
 	// This is necessary to transfer auth from previous connection to another DC.
 	setup SetupCallback // nilable
 
+	// onDead is called on connection death.
+	onDead func()
+
 	// Wrappers for external world, like logs or PRNG.
 	// Should be immutable.
 	clock clock.Clock // immutable
@@ -123,6 +126,9 @@ func (c *Conn) Run(ctx context.Context) (err error) {
 	defer func() {
 		if err != nil && ctx.Err() == nil {
 			c.log.Debug("Connection dead", zap.Error(err))
+			if c.onDead != nil {
+				c.onDead()
+			}
 		}
 	}()
 	return c.proto.Run(ctx, func(ctx context.Context) error {

telegram/internal/manager/create.go

@@ -22,6 +22,7 @@ type ConnOptions struct {
 	Device  DeviceConfig
 	Handler Handler
 	Setup   SetupCallback
+	OnDead  func()
 	Backoff func(ctx context.Context) backoff.BackOff
 }
 
@@ -69,6 +70,7 @@ func CreateConn(
 		gotConfig:   tdsync.NewReady(),
 		dead:        tdsync.NewReady(),
 		setup:       connOpts.Setup,
+		onDead:      connOpts.OnDead,
 		connBackoff: connOpts.Backoff,
 	}
 

telegram/migrate_to_dc_test.go

@@ -116,7 +116,7 @@ func newMigrationClient(t *testing.T, h migrationTestHandler) *Client {
 		migrationTimeout: 10 * time.Second,
 	}
 	client.init()
-	client.conn = client.createConn(0, manager.ConnModeUpdates, nil)
+	client.conn = client.createConn(0, manager.ConnModeUpdates, nil, nil)
 	client.cfg.Store(cfg)
 	return client
 }

telegram/options.go

@@ -48,6 +48,8 @@ type Options struct {
 
 	// ReconnectionBackoff configures and returns reconnection backoff object.
 	ReconnectionBackoff func() backoff.BackOff
+	// OnDead will be called on connection dead.
+	OnDead func()
 	// MigrationTimeout configures migration timeout.
 	MigrationTimeout time.Duration
 

telegram/pool.go

@@ -45,7 +45,7 @@ func (c *Client) Pool(max int64) (CloseInvoker, error) {
 	s := c.session.Load()
 	return c.createPool(s.DC, max, func() pool.Conn {
 		id := c.connsCounter.Inc()
-		return c.createConn(id, manager.ConnModeData, nil)
+		return c.createConn(id, manager.ConnModeData, nil, c.onDead)
 	})
 }
 
@@ -87,6 +87,7 @@ func (c *Client) dc(ctx context.Context, dcID int, max int64, dialer mtproto.Dia
 				DC:      dcID,
 				Device:  c.device,
 				Handler: c.asHandler(),
+				OnDead:  c.onDead,
 			},
 		)
 	})