| /* |
| * Copyright 2014 The gRPC 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 |
| * |
| * http://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 io.grpc; |
| |
| import com.google.common.base.Preconditions; |
| import java.io.BufferedInputStream; |
| import java.io.InputStream; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.List; |
| |
| /** |
| * Utility methods for working with {@link ServerInterceptor}s. |
| */ |
| public final class ServerInterceptors { |
| // Prevent instantiation |
| private ServerInterceptors() {} |
| |
| /** |
| * Create a new {@code ServerServiceDefinition} whose {@link ServerCallHandler}s will call |
| * {@code interceptors} before calling the pre-existing {@code ServerCallHandler}. The first |
| * interceptor will have its {@link ServerInterceptor#interceptCall} called first. |
| * |
| * @param serviceDef the service definition for which to intercept all its methods. |
| * @param interceptors array of interceptors to apply to the service. |
| * @return a wrapped version of {@code serviceDef} with the interceptors applied. |
| */ |
| public static ServerServiceDefinition interceptForward(ServerServiceDefinition serviceDef, |
| ServerInterceptor... interceptors) { |
| return interceptForward(serviceDef, Arrays.asList(interceptors)); |
| } |
| |
| public static ServerServiceDefinition interceptForward(BindableService bindableService, |
| ServerInterceptor... interceptors) { |
| return interceptForward(bindableService.bindService(), Arrays.asList(interceptors)); |
| } |
| |
| /** |
| * Create a new {@code ServerServiceDefinition} whose {@link ServerCallHandler}s will call |
| * {@code interceptors} before calling the pre-existing {@code ServerCallHandler}. The first |
| * interceptor will have its {@link ServerInterceptor#interceptCall} called first. |
| * |
| * @param serviceDef the service definition for which to intercept all its methods. |
| * @param interceptors list of interceptors to apply to the service. |
| * @return a wrapped version of {@code serviceDef} with the interceptors applied. |
| */ |
| public static ServerServiceDefinition interceptForward( |
| ServerServiceDefinition serviceDef, |
| List<? extends ServerInterceptor> interceptors) { |
| List<? extends ServerInterceptor> copy = new ArrayList<>(interceptors); |
| Collections.reverse(copy); |
| return intercept(serviceDef, copy); |
| } |
| |
| public static ServerServiceDefinition interceptForward( |
| BindableService bindableService, |
| List<? extends ServerInterceptor> interceptors) { |
| return interceptForward(bindableService.bindService(), interceptors); |
| } |
| |
| /** |
| * Create a new {@code ServerServiceDefinition} whose {@link ServerCallHandler}s will call |
| * {@code interceptors} before calling the pre-existing {@code ServerCallHandler}. The last |
| * interceptor will have its {@link ServerInterceptor#interceptCall} called first. |
| * |
| * @param serviceDef the service definition for which to intercept all its methods. |
| * @param interceptors array of interceptors to apply to the service. |
| * @return a wrapped version of {@code serviceDef} with the interceptors applied. |
| */ |
| public static ServerServiceDefinition intercept(ServerServiceDefinition serviceDef, |
| ServerInterceptor... interceptors) { |
| return intercept(serviceDef, Arrays.asList(interceptors)); |
| } |
| |
| public static ServerServiceDefinition intercept(BindableService bindableService, |
| ServerInterceptor... interceptors) { |
| Preconditions.checkNotNull(bindableService, "bindableService"); |
| return intercept(bindableService.bindService(), Arrays.asList(interceptors)); |
| } |
| |
| /** |
| * Create a new {@code ServerServiceDefinition} whose {@link ServerCallHandler}s will call |
| * {@code interceptors} before calling the pre-existing {@code ServerCallHandler}. The last |
| * interceptor will have its {@link ServerInterceptor#interceptCall} called first. |
| * |
| * @param serviceDef the service definition for which to intercept all its methods. |
| * @param interceptors list of interceptors to apply to the service. |
| * @return a wrapped version of {@code serviceDef} with the interceptors applied. |
| */ |
| public static ServerServiceDefinition intercept(ServerServiceDefinition serviceDef, |
| List<? extends ServerInterceptor> interceptors) { |
| Preconditions.checkNotNull(serviceDef, "serviceDef"); |
| if (interceptors.isEmpty()) { |
| return serviceDef; |
| } |
| ServerServiceDefinition.Builder serviceDefBuilder |
| = ServerServiceDefinition.builder(serviceDef.getServiceDescriptor()); |
| for (ServerMethodDefinition<?, ?> method : serviceDef.getMethods()) { |
| wrapAndAddMethod(serviceDefBuilder, method, interceptors); |
| } |
| return serviceDefBuilder.build(); |
| } |
| |
| public static ServerServiceDefinition intercept(BindableService bindableService, |
| List<? extends ServerInterceptor> interceptors) { |
| Preconditions.checkNotNull(bindableService, "bindableService"); |
| return intercept(bindableService.bindService(), interceptors); |
| } |
| |
| /** |
| * Create a new {@code ServerServiceDefinition} whose {@link MethodDescriptor} serializes to |
| * and from InputStream for all methods. The InputStream is guaranteed return true for |
| * markSupported(). The {@code ServerCallHandler} created will automatically |
| * convert back to the original types for request and response before calling the existing |
| * {@code ServerCallHandler}. Calling this method combined with the intercept methods will |
| * allow the developer to choose whether to intercept messages of InputStream, or the modeled |
| * types of their application. |
| * |
| * @param serviceDef the service definition to convert messages to InputStream |
| * @return a wrapped version of {@code serviceDef} with the InputStream conversion applied. |
| */ |
| @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1712") |
| public static ServerServiceDefinition useInputStreamMessages( |
| final ServerServiceDefinition serviceDef) { |
| final MethodDescriptor.Marshaller<InputStream> marshaller = |
| new MethodDescriptor.Marshaller<InputStream>() { |
| @Override |
| public InputStream stream(final InputStream value) { |
| return value; |
| } |
| |
| @Override |
| public InputStream parse(final InputStream stream) { |
| if (stream.markSupported()) { |
| return stream; |
| } else { |
| return new BufferedInputStream(stream); |
| } |
| } |
| }; |
| |
| return useMarshalledMessages(serviceDef, marshaller); |
| } |
| |
| /** |
| * Create a new {@code ServerServiceDefinition} whose {@link MethodDescriptor} serializes to |
| * and from T for all methods. The {@code ServerCallHandler} created will automatically |
| * convert back to the original types for request and response before calling the existing |
| * {@code ServerCallHandler}. Calling this method combined with the intercept methods will |
| * allow the developer to choose whether to intercept messages of T, or the modeled types |
| * of their application. This can also be chained to allow for interceptors to handle messages |
| * as multiple different T types within the chain if the added cost of serialization is not |
| * a concern. |
| * |
| * @param serviceDef the service definition to convert messages to T |
| * @return a wrapped version of {@code serviceDef} with the T conversion applied. |
| */ |
| @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1712") |
| public static <T> ServerServiceDefinition useMarshalledMessages( |
| final ServerServiceDefinition serviceDef, |
| final MethodDescriptor.Marshaller<T> marshaller) { |
| List<ServerMethodDefinition<?, ?>> wrappedMethods = |
| new ArrayList<ServerMethodDefinition<?, ?>>(); |
| List<MethodDescriptor<?, ?>> wrappedDescriptors = |
| new ArrayList<MethodDescriptor<?, ?>>(); |
| // Wrap the descriptors |
| for (final ServerMethodDefinition<?, ?> definition : serviceDef.getMethods()) { |
| final MethodDescriptor<?, ?> originalMethodDescriptor = definition.getMethodDescriptor(); |
| final MethodDescriptor<T, T> wrappedMethodDescriptor = |
| originalMethodDescriptor.toBuilder(marshaller, marshaller).build(); |
| wrappedDescriptors.add(wrappedMethodDescriptor); |
| wrappedMethods.add(wrapMethod(definition, wrappedMethodDescriptor)); |
| } |
| // Build the new service descriptor |
| final ServerServiceDefinition.Builder serviceBuilder = ServerServiceDefinition |
| .builder(new ServiceDescriptor(serviceDef.getServiceDescriptor().getName(), |
| wrappedDescriptors)); |
| // Create the new service definiton. |
| for (ServerMethodDefinition<?, ?> definition : wrappedMethods) { |
| serviceBuilder.addMethod(definition); |
| } |
| return serviceBuilder.build(); |
| } |
| |
| private static <ReqT, RespT> void wrapAndAddMethod( |
| ServerServiceDefinition.Builder serviceDefBuilder, ServerMethodDefinition<ReqT, RespT> method, |
| List<? extends ServerInterceptor> interceptors) { |
| ServerCallHandler<ReqT, RespT> callHandler = method.getServerCallHandler(); |
| for (ServerInterceptor interceptor : interceptors) { |
| callHandler = InterceptCallHandler.create(interceptor, callHandler); |
| } |
| serviceDefBuilder.addMethod(method.withServerCallHandler(callHandler)); |
| } |
| |
| static final class InterceptCallHandler<ReqT, RespT> implements ServerCallHandler<ReqT, RespT> { |
| public static <ReqT, RespT> InterceptCallHandler<ReqT, RespT> create( |
| ServerInterceptor interceptor, ServerCallHandler<ReqT, RespT> callHandler) { |
| return new InterceptCallHandler<ReqT, RespT>(interceptor, callHandler); |
| } |
| |
| private final ServerInterceptor interceptor; |
| private final ServerCallHandler<ReqT, RespT> callHandler; |
| |
| private InterceptCallHandler( |
| ServerInterceptor interceptor, ServerCallHandler<ReqT, RespT> callHandler) { |
| this.interceptor = Preconditions.checkNotNull(interceptor, "interceptor"); |
| this.callHandler = callHandler; |
| } |
| |
| @Override |
| public ServerCall.Listener<ReqT> startCall( |
| ServerCall<ReqT, RespT> call, |
| Metadata headers) { |
| return interceptor.interceptCall(call, headers, callHandler); |
| } |
| } |
| |
| static <OReqT, ORespT, WReqT, WRespT> ServerMethodDefinition<WReqT, WRespT> wrapMethod( |
| final ServerMethodDefinition<OReqT, ORespT> definition, |
| final MethodDescriptor<WReqT, WRespT> wrappedMethod) { |
| final ServerCallHandler<WReqT, WRespT> wrappedHandler = wrapHandler( |
| definition.getServerCallHandler(), |
| definition.getMethodDescriptor(), |
| wrappedMethod); |
| return ServerMethodDefinition.create(wrappedMethod, wrappedHandler); |
| } |
| |
| private static <OReqT, ORespT, WReqT, WRespT> ServerCallHandler<WReqT, WRespT> wrapHandler( |
| final ServerCallHandler<OReqT, ORespT> originalHandler, |
| final MethodDescriptor<OReqT, ORespT> originalMethod, |
| final MethodDescriptor<WReqT, WRespT> wrappedMethod) { |
| return new ServerCallHandler<WReqT, WRespT>() { |
| @Override |
| public ServerCall.Listener<WReqT> startCall( |
| final ServerCall<WReqT, WRespT> call, |
| final Metadata headers) { |
| final ServerCall<OReqT, ORespT> unwrappedCall = |
| new PartialForwardingServerCall<OReqT, ORespT>() { |
| @Override |
| protected ServerCall<WReqT, WRespT> delegate() { |
| return call; |
| } |
| |
| @Override |
| public void sendMessage(ORespT message) { |
| final InputStream is = originalMethod.streamResponse(message); |
| final WRespT wrappedMessage = wrappedMethod.parseResponse(is); |
| delegate().sendMessage(wrappedMessage); |
| } |
| |
| @Override |
| public MethodDescriptor<OReqT, ORespT> getMethodDescriptor() { |
| return originalMethod; |
| } |
| }; |
| |
| final ServerCall.Listener<OReqT> originalListener = originalHandler |
| .startCall(unwrappedCall, headers); |
| |
| return new PartialForwardingServerCallListener<WReqT>() { |
| @Override |
| protected ServerCall.Listener<OReqT> delegate() { |
| return originalListener; |
| } |
| |
| @Override |
| public void onMessage(WReqT message) { |
| final InputStream is = wrappedMethod.streamRequest(message); |
| final OReqT originalMessage = originalMethod.parseRequest(is); |
| delegate().onMessage(originalMessage); |
| } |
| }; |
| } |
| }; |
| } |
| } |