Add gRPC request scope support (#392)

spring-grpc-core/src/main/java/org/springframework/grpc/server/annotation/GrpcRequestScope.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2024-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.grpc.server.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.annotation.ScopedProxyMode;
+import org.springframework.core.annotation.AliasFor;
+
+@Target({ ElementType.TYPE, ElementType.METHOD })
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Scope("grpcRequest")
+public @interface GrpcRequestScope {
+
+	@AliasFor(annotation = Scope.class)
+	ScopedProxyMode proxyMode() default ScopedProxyMode.TARGET_CLASS;
+
+}

spring-grpc-core/src/main/java/org/springframework/grpc/server/scope/EnableGrpcScope.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2024-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.grpc.server.scope;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.context.annotation.Import;
+
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Import(GrpcScopeRegistrar.class)
+public @interface EnableGrpcScope {
+
+}

spring-grpc-core/src/main/java/org/springframework/grpc/server/scope/GrpcRequestScope.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2024-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.grpc.server.scope;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.beans.factory.ObjectFactory;
+import org.springframework.beans.factory.config.Scope;
+
+/**
+ * A {@link Scope} implementation for gRPC request-scoped beans.
+ *
+ * @author Fernando Rodrigues Ripol
+ */
+public class GrpcRequestScope implements Scope {
+
+	private static final ThreadLocal<Map<String, Object>> threadLocalScope = ThreadLocal.withInitial(HashMap::new);
+
+	@Override
+	public Object get(String name, ObjectFactory<?> objectFactory) {
+		Map<String, Object> scope = threadLocalScope.get();
+		Object bean = scope.get(name);
+		if (bean == null) {
+			bean = objectFactory.getObject();
+			scope.put(name, bean);
+		}
+		return bean;
+	}
+
+	@Override
+	public Object remove(String name) {
+		Map<String, Object> scope = threadLocalScope.get();
+		return scope.remove(name);
+	}
+
+	@Override
+	public void registerDestructionCallback(String name, Runnable callback) {
+	}
+
+	@Override
+	public Object resolveContextualObject(String key) {
+		return null;
+	}
+
+	@Override
+	public String getConversationId() {
+		return null;
+	}
+
+	public static void clear() {
+		threadLocalScope.remove();
+	}
+
+}

spring-grpc-core/src/main/java/org/springframework/grpc/server/scope/GrpcRequestScopeServerInterceptor.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2024-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.grpc.server.scope;
+
+import io.grpc.ForwardingServerCallListener;
+import io.grpc.Metadata;
+import io.grpc.ServerCall;
+import io.grpc.ServerCallHandler;
+import io.grpc.ServerInterceptor;
+
+/**
+ * A {@link ServerInterceptor} to manage the lifecycle of gRPC request-scoped beans.
+ *
+ * @author Fernando Rodrigues Ripol
+ */
+public class GrpcRequestScopeServerInterceptor implements ServerInterceptor {
+
+	@Override
+	public <ReqT, RespT> ServerCall.Listener<ReqT> interceptCall(ServerCall<ReqT, RespT> call, Metadata headers,
+			ServerCallHandler<ReqT, RespT> next) {
+		ServerCall.Listener<ReqT> delegate = next.startCall(call, headers);
+		return new ForwardingServerCallListener.SimpleForwardingServerCallListener<ReqT>(delegate) {
+			@Override
+			public void onComplete() {
+				try {
+					super.onComplete();
+				}
+				finally {
+					GrpcRequestScope.clear();
+				}
+			}
+
+			@Override
+			public void onCancel() {
+				try {
+					super.onCancel();
+				}
+				finally {
+					GrpcRequestScope.clear();
+				}
+			}
+		};
+	}
+
+}

spring-grpc-core/src/main/java/org/springframework/grpc/server/scope/GrpcScopeRegistrar.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2024-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.grpc.server.scope;
+
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.core.type.AnnotationMetadata;
+
+public class GrpcScopeRegistrar implements ImportBeanDefinitionRegistrar {
+
+	@Override
+	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
+		if (!registry.containsBeanDefinition("grpcRequestScope")) {
+			registry.registerBeanDefinition("grpcRequestScope", new RootBeanDefinition(GrpcRequestScope.class));
+		}
+		if (!registry.containsBeanDefinition("grpcRequestScopeServerInterceptor")) {
+			registry.registerBeanDefinition("grpcRequestScopeServerInterceptor",
+					new RootBeanDefinition(GrpcRequestScopeServerInterceptor.class));
+		}
+	}
+
+}

spring-grpc-core/src/test/java/org/springframework/grpc/server/annotation/GrpcRequestScopeTests.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2024-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.grpc.server.annotation;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.grpc.server.scope.EnableGrpcScope;
+
+class GrpcRequestScopeTests {
+
+	@Test
+	void testGrpcRequestScopeRegistration() {
+		try (AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(TestConfig.class)) {
+			assertThat(context.containsBean("testBean")).isTrue();
+		}
+	}
+
+	@Configuration
+	@EnableGrpcScope
+	static class TestConfig {
+
+		@Bean
+		@GrpcRequestScope
+		public TestBean testBean() {
+			return new TestBean();
+		}
+
+	}
+
+	static class TestBean {
+
+	}
+
+}