core/src/main/java/io/grpc/internal/InternalHandlerRegistry.java

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package io.grpc.internal;

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

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.annotation.Nullable;

final class InternalHandlerRegistry {

  private final List<ServerServiceDefinition> services;
  private final Map<String, ServerMethodDefinition<?, ?>> methods;

  private InternalHandlerRegistry(
      List<ServerServiceDefinition> services, Map<String, ServerMethodDefinition<?, ?>> methods) {
    this.services = services;
    this.methods = methods;
  }

  /**
   * Returns the service definitions in this registry.
   */
  public List<ServerServiceDefinition> getServices() {
    return services;
  }

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

  static class Builder {

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

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

    InternalHandlerRegistry build() {
      Map<String, ServerMethodDefinition<?, ?>> map =
          new HashMap<String, ServerMethodDefinition<?, ?>>();
      for (ServerServiceDefinition service : services.values()) {
        for (ServerMethodDefinition<?, ?> method : service.getMethods()) {
          map.put(method.getMethodDescriptor().getFullMethodName(), method);
        }
      }
      return new InternalHandlerRegistry(
          Collections.unmodifiableList(new ArrayList<ServerServiceDefinition>(services.values())),
          Collections.unmodifiableMap(map));
    }
  }
}