Fix the issue with repeatedly building plugin RouterFunction for CustomEndpoints (#4890)

* fix: OOM occured when using ab to test custom endpoints provided by plugin

* refactor: custom endpoints to rotuer function register for plugin

* refactor: bean post processor register

* Register AggregatedRouterFunction bean instead of adding bean factory post processor

* Remove debug lines

---------

Co-authored-by: John Niang <johnniang@foxmail.com>

application/src/main/java/run/halo/app/plugin/AggregatedRouterFunction.java

@@ -0,0 +1,38 @@
+package run.halo.app.plugin;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.web.reactive.function.server.HandlerFunction;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Mono;
+import run.halo.app.core.extension.endpoint.CustomEndpoint;
+import run.halo.app.core.extension.endpoint.CustomEndpointsBuilder;
+
+/**
+ * Aggregated router function built from all custom endpoints.
+ *
+ * @author johnniang
+ */
+public class AggregatedRouterFunction implements RouterFunction<ServerResponse> {
+
+    private final RouterFunction<ServerResponse> aggregated;
+
+    public AggregatedRouterFunction(ObjectProvider<CustomEndpoint> customEndpoints) {
+        var builder = new CustomEndpointsBuilder();
+        customEndpoints.orderedStream()
+            .forEach(builder::add);
+        this.aggregated = builder.build();
+    }
+
+    @Override
+    public Mono<HandlerFunction<ServerResponse>> route(ServerRequest request) {
+        return aggregated.route(request);
+    }
+
+    @Override
+    public void accept(RouterFunctions.Visitor visitor) {
+        this.aggregated.accept(visitor);
+    }
+}

application/src/main/java/run/halo/app/plugin/PluginApplicationInitializer.java

@@ -36,6 +36,7 @@ import run.halo.app.infra.properties.HaloProperties;
  */
 @Slf4j
 public class PluginApplicationInitializer {
+
     protected final HaloPluginManager haloPluginManager;
 
     private final ExtensionContextRegistry contextRegistry = ExtensionContextRegistry.getInstance();
@@ -89,6 +90,8 @@ public class PluginApplicationInitializer {
         AnnotationConfigUtils.registerAnnotationConfigProcessors(beanFactory);
         stopWatch.stop();
 
+        pluginApplicationContext.registerBean(AggregatedRouterFunction.class);
+
         beanFactory.registerSingleton("pluginContext", createPluginContext(plugin));
         // TODO deprecated
         beanFactory.registerSingleton("pluginWrapper", haloPluginManager.getPlugin(pluginId));

application/src/main/java/run/halo/app/plugin/PluginCompositeRouterFunction.java

@@ -2,7 +2,7 @@ package run.halo.app.plugin;
 
 import static run.halo.app.plugin.ExtensionContextRegistry.getInstance;
 
-import java.util.ArrayList;
+import com.google.common.collect.Iterables;
 import java.util.List;
 import org.springframework.context.support.AbstractApplicationContext;
 import org.springframework.lang.NonNull;
@@ -14,8 +14,6 @@ import org.springframework.web.reactive.function.server.ServerRequest;
 import org.springframework.web.reactive.function.server.ServerResponse;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
-import run.halo.app.core.extension.endpoint.CustomEndpoint;
-import run.halo.app.core.extension.endpoint.CustomEndpointsBuilder;
 import run.halo.app.plugin.resources.ReverseProxyRouterFunctionRegistry;
 
 /**
@@ -48,7 +46,7 @@ public class PluginCompositeRouterFunction implements RouterFunction<ServerRespo
     }
 
     @SuppressWarnings("unchecked")
-    private List<RouterFunction<ServerResponse>> routerFunctions() {
+    private Iterable<RouterFunction<ServerResponse>> routerFunctions() {
         getInstance().acquireReadLock();
         try {
             List<PluginApplicationContext> contexts = getInstance().getPluginApplicationContexts()
@@ -64,18 +62,7 @@ public class PluginCompositeRouterFunction implements RouterFunction<ServerRespo
                 .toList();
             var reverseProxies = reverseProxyRouterFunctionFactory.getRouterFunctions();
 
-            var endpointBuilder = new CustomEndpointsBuilder();
-            contexts.forEach(context -> context.getBeanProvider(CustomEndpoint.class)
-                .orderedStream()
-                .forEach(endpointBuilder::add));
-            var customEndpoint = endpointBuilder.build();
-
-            List<RouterFunction<ServerResponse>> routerFunctions =
-                new ArrayList<>(rawRouterFunctions.size() + reverseProxies.size() + 1);
-            routerFunctions.addAll(rawRouterFunctions);
-            routerFunctions.addAll(reverseProxies);
-            routerFunctions.add(customEndpoint);
-            return routerFunctions;
+            return Iterables.concat(rawRouterFunctions, reverseProxies);
         } finally {
             getInstance().releaseReadLock();
         }

application/src/main/java/run/halo/app/plugin/event/HaloPluginStartedEvent.java

@@ -1,24 +1,23 @@
 package run.halo.app.plugin.event;
 
+import lombok.Getter;
 import org.pf4j.PluginWrapper;
 import org.springframework.context.ApplicationEvent;
+import org.springframework.util.Assert;
 
 /**
  * This event will be published to <b>application context</b> once plugin is started.
  *
  * @author guqing
  */
+@Getter
 public class HaloPluginStartedEvent extends ApplicationEvent {
 
     private final PluginWrapper plugin;
 
-
     public HaloPluginStartedEvent(Object source, PluginWrapper plugin) {
         super(source);
+        Assert.notNull(plugin, "Plugin must not be null.");
         this.plugin = plugin;
     }
-
-    public PluginWrapper getPlugin() {
-        return plugin;
-    }
 }

application/src/test/java/run/halo/app/plugin/PluginCompositeRouterFunctionTest.java

@@ -24,7 +24,6 @@ import org.springframework.web.reactive.function.server.support.RouterFunctionMa
 import org.springframework.web.server.ServerWebExchange;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
-import run.halo.app.core.extension.endpoint.CustomEndpoint;
 import run.halo.app.plugin.resources.ReverseProxyRouterFunctionRegistry;
 
 /**
@@ -43,9 +42,6 @@ class PluginCompositeRouterFunctionTest {
     @Mock
     ObjectProvider<RouterFunction> rawRouterFunctionsProvider;
 
-    @Mock
-    ObjectProvider<CustomEndpoint> customEndpointsProvider;
-
     @InjectMocks
     PluginCompositeRouterFunction compositeRouterFunction;
 
@@ -59,11 +55,9 @@ class PluginCompositeRouterFunctionTest {
         ExtensionContextRegistry.getInstance().register("fake-plugin", fakeContext);
 
         when(rawRouterFunctionsProvider.orderedStream()).thenReturn(Stream.empty());
-        when(customEndpointsProvider.orderedStream()).thenReturn(Stream.empty());
 
         when(fakeContext.getBeanProvider(RouterFunction.class))
             .thenReturn(rawRouterFunctionsProvider);
-        when(fakeContext.getBeanProvider(CustomEndpoint.class)).thenReturn(customEndpointsProvider);
 
         compositeRouterFunction =
             new PluginCompositeRouterFunction(reverseProxyRouterFunctionRegistry);
@@ -93,11 +87,10 @@ class PluginCompositeRouterFunctionTest {
             .verify();
 
         verify(rawRouterFunctionsProvider).orderedStream();
-        verify(customEndpointsProvider).orderedStream();
     }
 
     private ServerWebExchange createExchange(String urlTemplate) {
         return MockServerWebExchange.from(MockServerHttpRequest.get(urlTemplate));
     }
 
-}
+}