Fix placeholder cache reuse across backend switches

common/src/main/java/net/william278/papiproxybridge/api/PlaceholderAPI.java

@@ -121,7 +121,7 @@ public static void clearCache(@NotNull UUID player) {
         });
     }
 
-    private record CacheKey(@NotNull UUID requester, @NotNull UUID formatFor) {
+    private record CacheKey(@NotNull UUID requester, @NotNull UUID formatFor, @NotNull String scope) {
 
         private boolean contains(@NotNull UUID player) {
             return requester.equals(player) || formatFor.equals(player);
@@ -168,7 +168,7 @@ private CompletableFuture<String> formatPlaceholders(@NotNull String text, @NotN
         if (!requester.isConnected()) {
             return CompletableFuture.completedFuture(text);
         }
-        final CacheKey cacheKey = new CacheKey(requester.getUniqueId(), formatFor);
+        final CacheKey cacheKey = new CacheKey(requester.getUniqueId(), formatFor, requester.getPlaceholderCacheScope());
         if (cacheExpiry > 0 && cache.containsKey(cacheKey) && cache.get(cacheKey).containsKey(text)) {
             return CompletableFuture.completedFuture(cache.get(cacheKey).get(text));
         }
@@ -273,7 +273,7 @@ private CompletableFuture<Component> formatComponentPlaceholders(@NotNull String
         if (!requester.isConnected()) {
             return CompletableFuture.completedFuture(Component.text(text));
         }
-        final CacheKey cacheKey = new CacheKey(requester.getUniqueId(), formatFor);
+        final CacheKey cacheKey = new CacheKey(requester.getUniqueId(), formatFor, requester.getPlaceholderCacheScope());
         if (cacheExpiry > 0 && componentCache.containsKey(cacheKey) && componentCache.get(cacheKey).containsKey(text)) {
             return CompletableFuture.completedFuture(componentCache.get(cacheKey).get(text));
         }

common/src/main/java/net/william278/papiproxybridge/user/OnlineUser.java

@@ -36,6 +36,18 @@ public interface OnlineUser {
     @NotNull
     UUID getUniqueId();
 
+    /**
+     * Returns the runtime context in which placeholder results may be reused.
+     * Implementations should change this value when the same user can resolve
+     * placeholders against a different backend or data source.
+     *
+     * @return the placeholder cache scope
+     */
+    @NotNull
+    default String getPlaceholderCacheScope() {
+        return "";
+    }
+
     default void sendMessage(@NotNull PAPIProxyBridge plugin, @NotNull Request request, boolean wantsJson, boolean isRequest) {
         final ByteArrayDataOutput messageWriter = ByteStreams.newDataOutput();
         final UUID uuid = getUniqueId();

common/src/test/java/net/william278/papiproxybridge/api/PlaceholderAPITest.java

@@ -36,6 +36,7 @@
 import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Level;
 
@@ -89,6 +90,30 @@ void componentCacheUsesRequesterAndFormattingTarget() {
         assertEquals(3, bridge.requests.get());
     }
 
+    @Test
+    void cacheIsIsolatedByBackendServer() {
+        final TestProxyUser proxyUser = new TestProxyUser(UUID.randomUUID(), "lobby");
+        bridge.response = "lobby";
+        assertEquals("lobby", api.formatPlaceholders("%server_name%", proxyUser).join());
+
+        proxyUser.serverName = "survival";
+        bridge.response = "survival";
+        assertEquals("survival", api.formatPlaceholders("%server_name%", proxyUser).join());
+        assertEquals(2, bridge.requests.get());
+    }
+
+    @Test
+    void componentCacheIsIsolatedByBackendServer() {
+        final TestProxyUser proxyUser = new TestProxyUser(UUID.randomUUID(), "lobby");
+        bridge.response = "{\"text\":\"lobby\"}";
+        assertEquals(Component.text("lobby"), api.formatComponentPlaceholders("%server_name%", proxyUser).join());
+
+        proxyUser.serverName = "survival";
+        bridge.response = "{\"text\":\"survival\"}";
+        assertEquals(Component.text("survival"), api.formatComponentPlaceholders("%server_name%", proxyUser).join());
+        assertEquals(2, bridge.requests.get());
+    }
+
     @Test
     void retriesFailedRequests() {
         api.setRetryTimes(1);
@@ -99,11 +124,23 @@ void retriesFailedRequests() {
         assertEquals(2, bridge.requests.get());
     }
 
+    @Test
+    void retriesTimedOutRequests() throws Exception {
+        api.setRequestTimeout(20);
+        api.setRetryTimes(1);
+        bridge.timeouts = 1;
+        bridge.response = "formatted";
+
+        assertEquals("formatted", api.formatPlaceholders("%name%", requester).get(1, TimeUnit.SECONDS));
+        assertEquals(2, bridge.requests.get());
+    }
+
     private static final class TestBridge implements PAPIProxyBridge {
         private final TestUser user;
         private final AtomicInteger requests = new AtomicInteger();
         private String response;
         private int failures;
+        private int timeouts;
 
         private TestBridge(TestUser user) {
             this.user = user;
@@ -128,6 +165,9 @@ public Optional<? extends OnlineUser> findPlayer(@NotNull UUID uuid) {
         public CompletableFuture<String> createRequest(@NotNull String text, @NotNull OnlineUser requester,
                                                        @NotNull UUID formatFor, boolean wantsJson, long requestTimeout) {
             requests.incrementAndGet();
+            if (timeouts-- > 0) {
+                return new CompletableFuture<>();
+            }
             if (failures-- > 0) {
                 return CompletableFuture.failedFuture(new IllegalStateException("failed"));
             }
@@ -182,4 +222,33 @@ private record TestUser(UUID uuid) implements OnlineUser {
         public void handleMessage(@NotNull PAPIProxyBridge plugin, @NotNull Request message, boolean wantsJson) {
         }
     }
+
+    private static final class TestProxyUser implements OnlineUser {
+        private final UUID uuid;
+        private String serverName;
+
+        private TestProxyUser(UUID uuid, String serverName) {
+            this.uuid = uuid;
+            this.serverName = serverName;
+        }
+
+        @Override
+        public @NotNull String getUsername() {
+            return "proxy-user";
+        }
+
+        @Override
+        public @NotNull UUID getUniqueId() {
+            return uuid;
+        }
+
+        @Override
+        public @NotNull String getPlaceholderCacheScope() {
+            return serverName;
+        }
+
+        @Override
+        public void handleMessage(@NotNull PAPIProxyBridge plugin, @NotNull Request message, boolean wantsJson) {
+        }
+    }
 }

proxy/src/main/java/net/william278/papiproxybridge/user/ProxyUser.java

@@ -43,4 +43,10 @@ default void handleMessage(@NotNull PAPIProxyBridge plugin, @NotNull Request mes
     @NotNull
     String getServerName();
 
+    @Override
+    @NotNull
+    default String getPlaceholderCacheScope() {
+        return getServerName();
+    }
+
 }