fix(velocity): 传送没连上且后端没给理由时重新排队重拨，最多三次

plugins/velocity/src/main/java/best/lolicon/felis/velocity/WaitingRouter.java

@@ -46,7 +46,8 @@ import java.util.function.LongSupplier;
  * reports ready, transfers everyone waiting on it. A waiter stays as long as its
  * server is on the way up, through the operator's restart backoff, and drops out on a
  * successful transfer, when the player leaves the proxy, when the start is given up or
- * the server stopped, or when felis-api stops answering for the wait window.
+ * the server stopped, or when felis-api stops answering for the wait window. A transfer
+ * that fails without the backend saying why queues the player again for another dial.
  *
  * <p>Every transition out of login is checked against felis-api's link status, and
  * command/menu queue entries are checked the same way. The wake is then gated
@@ -79,6 +80,9 @@ public final class WaitingRouter {
     // The login gate re-sends its release with backoff (and during a felis-api outage
     // on every retry), so a denial line is shown at most once per this interval.
     private static final long GATE_NOTICE_INTERVAL_MILLIS = 15_000L;
+    // How many times a player is dialled into a server that fails the connect without
+    // saying why. The retries ride the queue, a tick apart, each after a fresh ready poll.
+    private static final int TRANSFER_ATTEMPTS = 3;
 
     private final ProxyServer proxy;
     private final Logger log;
@@ -249,7 +253,8 @@ public final class WaitingRouter {
                     NamedTextColor.RED));
             return;
         }
-        transfer(player, lobbyServer, lobby.get());
+        // One dial: the lobby is no queue target, and the player can simply ask again.
+        transfer(player, lobbyServer, lobby.get(), false, TRANSFER_ATTEMPTS);
     }
 
     /**
@@ -505,7 +510,7 @@ public final class WaitingRouter {
             if (w.fromMenu && listener != null) {
                 listener.onReady(player, w.serverName);
             }
-            transfer(player, w.serverName, backend.get());
+            transfer(player, w.serverName, backend.get(), w.fromMenu, w.attempts + 1);
         }
     }
 
@@ -644,7 +649,7 @@ public final class WaitingRouter {
         if (fromMenu && listener != null) {
             listener.onReady(player, serverName);
         }
-        transfer(player, serverName, backend.get());
+        transfer(player, serverName, backend.get(), fromMenu, 1);
         return true;
     }
 
@@ -724,7 +729,7 @@ public final class WaitingRouter {
                        : "Starting « " + serverName + " » — you'll be moved in automatically.",
                     NamedTextColor.GRAY));
         }
-        waiting.put(id, new Waiter(serverName, clock.getAsLong(), fromMenu));
+        waiting.put(id, new Waiter(serverName, clock.getAsLong(), fromMenu, 0));
     }
 
     // The server's start failed and its automatic retries are spent: nothing more is
@@ -745,26 +750,51 @@ public final class WaitingRouter {
                 NamedTextColor.RED));
     }
 
-    private void transfer(Player player, String serverName, RegisteredServer backend) {
+    /**
+     * transfer dials a player into a server; attempt numbers this dial among the ones
+     * made for the same move. A connect that fails without the backend saying why — the
+     * server went away between the ready poll and the dial, its port is not listening
+     * yet, the network dropped — puts the player back in the queue until
+     * {@link #TRANSFER_ATTEMPTS} dials are spent: a later tick polls the server again,
+     * registers the address it reports and dials once more. A refusal that carries a
+     * reason (ban, whitelist, full, mods) is final at once, and so is a dial another
+     * connection or a pre-connect listener pre-empted.
+     */
+    private void transfer(Player player, String serverName, RegisteredServer backend,
+                          boolean fromMenu, int attempt) {
         player.createConnectionRequest(backend).connect().whenComplete((result, err) -> {
-            if (err != null || (result != null && !result.isSuccessful())) {
-                plugin.stats().count(ProxyStats.Event.TRANSFER_FAILED);
-                log.warn("Felis: transfer of {} to {} failed: {}", player.getUniqueId(), serverName,
-                        err != null ? err.toString() : result.getStatus());
-                boolean zh = FelisVelocityPlugin.zh(player);
-                Component line = Component.text(
-                        zh ? "无法把你连接到「" + serverName + "」。"
-                           : "Couldn't connect you to « " + serverName + " ».",
-                        NamedTextColor.RED);
-                // A backend that refuses the login says why (ban, whitelist, full, mods);
-                // "please try again" is wrong advice for all of those.
-                Optional<Component> reason = result == null ? Optional.empty() : result.getReasonComponent();
-                line = reason.isPresent()
-                        ? line.append(Component.text(zh ? " 原因：" : " Reason: ", NamedTextColor.RED))
-                              .append(reason.get())
-                        : line.append(Component.text(zh ? "请重试。" : " Please try again.", NamedTextColor.RED));
-                player.sendMessage(line);
+            if (err == null && (result == null || result.isSuccessful())) {
+                return;
             }
+            plugin.stats().count(ProxyStats.Event.TRANSFER_FAILED);
+            log.warn("Felis: transfer of {} to {} failed (attempt {}/{}): {}", player.getUniqueId(), serverName,
+                    attempt, TRANSFER_ATTEMPTS, err != null ? err.toString() : result.getStatus());
+            boolean zh = FelisVelocityPlugin.zh(player);
+            boolean unexplained = err != null
+                    || (result.getStatus() == ConnectionRequestBuilder.Status.SERVER_DISCONNECTED
+                        && result.getReasonComponent().isEmpty());
+            // putIfAbsent: a player who queued for another server meanwhile keeps that wait.
+            if (unexplained && attempt < TRANSFER_ATTEMPTS
+                    && waiting.putIfAbsent(player.getUniqueId(),
+                            new Waiter(serverName, clock.getAsLong(), fromMenu, attempt)) == null) {
+                player.sendMessage(Component.text(
+                        zh ? "没能连上「" + serverName + "」，稍后自动重试……"
+                           : "Couldn't reach « " + serverName + " »; trying again shortly…",
+                        NamedTextColor.YELLOW));
+                return;
+            }
+            Component line = Component.text(
+                    zh ? "无法把你连接到「" + serverName + "」。"
+                       : "Couldn't connect you to « " + serverName + " ».",
+                    NamedTextColor.RED);
+            // A backend that refuses the login says why (ban, whitelist, full, mods);
+            // "please try again" is wrong advice for all of those.
+            Optional<Component> reason = result == null ? Optional.empty() : result.getReasonComponent();
+            line = reason.isPresent()
+                    ? line.append(Component.text(zh ? " 原因：" : " Reason: ", NamedTextColor.RED))
+                          .append(reason.get())
+                    : line.append(Component.text(zh ? "请重试。" : " Please try again.", NamedTextColor.RED));
+            player.sendMessage(line);
         });
     }
 
@@ -786,6 +816,7 @@ public final class WaitingRouter {
         final String serverName;
         final boolean fromMenu; // true → notify the felis:control face on transfer
         final long sinceMillis;
+        final int attempts; // dials into serverName already made and failed
         // Only the drain touches these, one tick at a time (the ticking flag orders
         // the ticks), so they need no further synchronization.
         long deadlineMillis;
@@ -793,9 +824,10 @@ public final class WaitingRouter {
         int restartsSeen;
         boolean stopSeen;
 
-        Waiter(String serverName, long nowMillis, boolean fromMenu) {
+        Waiter(String serverName, long nowMillis, boolean fromMenu, int attempts) {
             this.serverName = serverName;
             this.fromMenu = fromMenu;
+            this.attempts = attempts;
             this.sinceMillis = nowMillis;
             this.deadlineMillis = nowMillis + WAIT_TIMEOUT_MILLIS;
             this.noticedMillis = nowMillis;

plugins/velocity/test/best/lolicon/felis/velocity/Fakes.java

@@ -19,6 +19,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Proxy;
+import java.net.ConnectException;
 import java.net.InetSocketAddress;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
@@ -239,6 +240,8 @@ final class Fakes {
         volatile String virtualHost;
         volatile RegisteredServer current;
         volatile boolean connectSucceeds = true;
+        /** connectThrows fails every connect the way an unreachable backend does, with no result. */
+        volatile boolean connectThrows;
         volatile String disconnectedWith;
         final List<String> messages = Collections.synchronizedList(new ArrayList<>());
         /**
@@ -331,6 +334,10 @@ final class Fakes {
                             status = ConnectionRequestBuilder.Status.CONNECTION_CANCELLED;
                         } else {
                             connects.add(dest.getServerInfo().getName());
+                            if (connectThrows) {
+                                return CompletableFuture.failedFuture(
+                                        new ConnectException("Connection refused"));
+                            }
                             status = connectSucceeds && refusal == null
                                     ? ConnectionRequestBuilder.Status.SUCCESS
                                     : ConnectionRequestBuilder.Status.SERVER_DISCONNECTED;

plugins/velocity/test/best/lolicon/felis/velocity/WaitingRouterTest.java

@@ -586,24 +586,87 @@ public final class WaitingRouterTest {
                 () -> log.count("WARN", "join-event for " + p.id + " on beta failed (status=500)") == 1);
         api.joinStatus = 204;
 
-        // A transfer the backend refuses is counted, logged and told.
-        Fakes.FakePlayer refused = player(null, true);
-        refused.current = lobby;
-        refused.connectSucceeds = false;
-        router.enqueueFromInvite(refused.player, "beta");
-        // The chat line is the last thing the failure path does; the count comes first.
-        Fakes.await("failed transfer: told", () -> refused.said("Couldn't connect you to « beta »"));
-        assertEq("failed transfer counted", 1L, plugin.stats().total(ProxyStats.Event.TRANSFER_FAILED));
-        assertEq("failed transfer: logged", 1, log.count("WARN", "transfer of " + refused.id + " to beta failed"));
+        // A connect that fails without the backend saying why puts the player back in the
+        // queue; the next tick polls the server again and dials once more.
+        long failed = plugin.stats().total(ProxyStats.Event.TRANSFER_FAILED);
+        int queued = router.waitingCount();
+        Fakes.FakePlayer flaky = player(null, true);
+        flaky.current = lobby;
+        flaky.connectThrows = true;
+        router.enqueueFromInvite(flaky.player, "beta");
+        // The chat line is the last thing the failure path does; the requeue comes first.
+        Fakes.await("unreachable: told it retries", () -> flaky.said("Couldn't reach « beta »; trying again shortly"));
+        assertEq("unreachable: queued again", queued + 1, router.waitingCount());
+        assertEq("unreachable: counted", failed + 1, plugin.stats().total(ProxyStats.Event.TRANSFER_FAILED));
+        assertEq("unreachable: logged", 1,
+                log.count("WARN", "transfer of " + flaky.id + " to beta failed (attempt 1/3)"));
+        assertEq("unreachable: no final word yet", false, flaky.said("Couldn't connect you"));
+        flaky.connectThrows = false;
+        int polls = api.count("GET " + SERVERS + "beta/status");
+        router.tick();
+        assertEq("retry: polled again", polls + 1, api.count("GET " + SERVERS + "beta/status"));
+        assertEq("retry: dialled again, and in", List.of("beta", "beta"), List.copyOf(flaky.connects));
+        assertEq("retry: out of the queue", queued, router.waitingCount());
+        assertEq("retry: nothing more counted", failed + 1, plugin.stats().total(ProxyStats.Event.TRANSFER_FAILED));
 
-        // A backend that kicks the login says why; "please try again" is wrong for a ban.
+        // The dials are bounded: a backend that keeps dropping them gets the final word on
+        // the third. A menu wait stays one through its retries, so the lobby hears each.
+        List<String> told = Collections.synchronizedList(new ArrayList<>());
+        router.setMenuTransferListener((pl, server) -> told.add(pl.getUsername() + "@" + server));
+        Fakes.FakePlayer dropped = player(null, true);
+        dropped.current = lobby;
+        dropped.connectSucceeds = false;
+        router.enqueueFromMenu(dropped.player, "beta");
+        Fakes.await("dropped: queued again", () -> dropped.said("Couldn't reach « beta »; trying again shortly"));
+        router.tick();
+        assertEq("dropped: second dial", 2, dropped.connects.size());
+        assertEq("dropped: queued after the second", queued + 1, router.waitingCount());
+        router.tick();
+        assertEq("dropped: third dial", 3, dropped.connects.size());
+        assertEq("dropped: given up", queued, router.waitingCount());
+        assertEq("dropped: told to try again", true, dropped.said("Couldn't connect you to « beta ». Please try again."));
+        assertEq("dropped: one final word", 1, count(dropped.messages, "Couldn't connect you"));
+        assertEq("dropped: every dial counted", failed + 4, plugin.stats().total(ProxyStats.Event.TRANSFER_FAILED));
+        String at = dropped.name + "@beta";
+        assertEq("dropped: the lobby told before every dial", List.of(at, at, at), List.copyOf(told));
+        router.tick();
+        assertEq("dropped: no fourth dial", 3, dropped.connects.size());
+
+        // A player already waiting for another server keeps that wait: the failed join is
+        // told as final instead of replacing it.
+        Fakes.FakePlayer busy = player(null, true);
+        busy.current = lobby;
+        router.enqueueFromCommand(busy.player, "zeta");
+        Fakes.await("busy: waiting for zeta", () -> router.waitingCount() == queued + 1);
+        busy.connectThrows = true;
+        router.enqueueFromInvite(busy.player, "beta");
+        Fakes.await("busy: told", () -> busy.said("Couldn't connect you to « beta ». Please try again."));
+        router.tick();
+        assertEq("busy: beta not dialled again", 1, busy.connects.size());
+        assertEq("busy: still waiting for zeta", queued + 1, router.waitingCount());
+        router.onDisconnect(new DisconnectEvent(busy.player, DisconnectEvent.LoginStatus.SUCCESSFUL_LOGIN));
+
+        // A pre-connect listener that cancels the move is final too.
+        Fakes.FakePlayer cancelled = player(null, true);
+        cancelled.current = lobby;
+        cancelled.preConnect = target -> null;
+        router.enqueueFromInvite(cancelled.player, "beta");
+        Fakes.await("cancelled: told", () -> cancelled.said("Couldn't connect you to « beta »"));
+        assertEq("cancelled: not queued", queued, router.waitingCount());
+        assertEq("failed transfers counted", failed + 6, plugin.stats().total(ProxyStats.Event.TRANSFER_FAILED));
+
+        // A backend that kicks the login says why; "please try again" is wrong for a ban,
+        // and so is dialling again.
         Fakes.FakePlayer full = player(null, true);
         full.current = lobby;
         full.refusals.put("beta", "The server is full");
         router.enqueueFromInvite(full.player, "beta");
         Fakes.await("refused transfer: told the reason", () -> full.said("Couldn't connect you to « beta ». Reason: The server is full"));
-        assertEq("refused transfer counted", 2L, plugin.stats().total(ProxyStats.Event.TRANSFER_FAILED));
+        assertEq("refused transfer counted", failed + 7, plugin.stats().total(ProxyStats.Event.TRANSFER_FAILED));
         assertEq("refused transfer: no retry advice", false, full.said("try again"));
+        assertEq("refused transfer: not queued", queued, router.waitingCount());
+        router.tick();
+        assertEq("refused transfer: dialled once", 1, full.connects.size());
     }
 
     // /felis lobby and /felis go lobby: the lobby is a system server, so it never
@@ -641,6 +704,15 @@ public final class WaitingRouterTest {
         full.refusals.put("lobby", "Server is full");
         router.toLobby(full.player);
         Fakes.await("lobby refused: told", () -> full.said("Couldn't connect you to « lobby ». Reason: Server is full"));
+
+        // The lobby gets one dial: it is no queue target, and the player can ask again.
+        Fakes.FakePlayer cut = player(null, true);
+        cut.current = beta;
+        cut.connectThrows = true;
+        int queued = router.waitingCount();
+        router.toLobby(cut.player);
+        assertEq("lobby unreachable: told", true, cut.said("Couldn't connect you to « lobby ». Please try again."));
+        assertEq("lobby unreachable: not queued", queued, router.waitingCount());
     }
 
     private static void disconnectAndRelease() {