HandlerRegistry.java

/*
 * Copyright 2016 LINE Corporation
 *
 * LINE Corporation licenses this file to you 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.
 */
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 * Copyright 2016, Google Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
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 *
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package com.linecorp.armeria.server.grpc;

import static java.util.Objects.requireNonNull;

import java.util.HashMap;
import java.util.List;

import javax.annotation.Nullable;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;

import io.grpc.ServerMethodDefinition;
import io.grpc.ServerServiceDefinition;

/**
 * A registry of the implementation methods bound to a {@link GrpcService}. Used for method dispatch and
 * documentation generation.
 */
final class HandlerRegistry {
    private final List<ServerServiceDefinition> services;
    private final ImmutableMap<String, ServerMethodDefinition<?, ?>> methods;

    private HandlerRegistry(List<ServerServiceDefinition> services,
                            ImmutableMap<String, ServerMethodDefinition<?, ?>> methods) {
        this.services = requireNonNull(services, "services");
        this.methods = requireNonNull(methods, "methods");
    }

    @Nullable
    ServerMethodDefinition<?, ?> lookupMethod(String methodName) {
        return methods.get(methodName);
    }

    List<ServerServiceDefinition> services() {
        return services;
    }

    static class Builder {
        // Store per-service first, to make sure services are added/replaced atomically.
        private final HashMap<String, ServerServiceDefinition> services =
                new HashMap<String, ServerServiceDefinition>();

        Builder addService(ServerServiceDefinition service) {
            services.put(service.getServiceDescriptor().getName(), service);
            return this;
        }

        HandlerRegistry build() {
            ImmutableMap.Builder<String, ServerMethodDefinition<?, ?>> mapBuilder =
                    ImmutableMap.builder();
            for (ServerServiceDefinition service : services.values()) {
                for (ServerMethodDefinition<?, ?> method : service.getMethods()) {
                    mapBuilder.put(method.getMethodDescriptor().getFullMethodName(), method);
                }
            }
            return new HandlerRegistry(ImmutableList.copyOf(services.values()), mapBuilder.build());
        }
    }
}