Interceptores de gRPC personalizados

La biblioteca cliente .NET usa interceptores de gRPC de forma interna para fines de registro, pero también te permite agregar tus propios interceptores de gRPC personalizados. Esta función se puede usar para registrar métricas en un agregador de registros personalizado o transformar las solicitudes a la API de Google Ads.

Para agregar un interceptor de gRPC personalizado, implementa una clase que extienda la clase Grpc.Core.Interceptors.Interceptor y adjúntala a tu GoogleAdsClient con el método AddInterceptor.

Ten en cuenta que interceptar solicitudes de gRPC de transmisión y no de transmisión requiere anular dos métodos diferentes de la clase Interceptor: AsyncUnaryCall y AsyncServerStreamingCall, respectivamente.

El espacio de nombres Google.Ads.Gax.Interceptors proporciona clases de utilidad que se pueden usar en interceptores personalizados para facilitar el control de excepciones.

En el siguiente ejemplo de código, se implementa un interceptor de llamadas de gRPC de transmisión y sin transmisión:

// Copyright 2024 Google LLC
//
// 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.
using CommandLine;
using Google.Api.Gax;
using Google.Ads.Gax.Examples;
using Google.Ads.Gax.Interceptors;
using Google.Ads.GoogleAds.Lib;
using Google.Ads.GoogleAds.V16.Errors;
using Google.Ads.GoogleAds.V16.Services;
using Grpc.Core;
using Grpc.Core.Interceptors;
using System;

using System.Threading.Tasks;

namespace Google.Ads.GoogleAds.Examples.V16
{
    /// <summary>
    /// This code example shows how to add a custom gRPC interceptor.
    /// </summary>
    public class AddCustomGrpcInterceptor : ExampleBase
    {
        /// <summary>
        /// Command line options for running the <see cref="AddCustomGrpcInterceptor"/> example.
        /// </summary>
        public class Options : OptionsBase
        {
            /// <summary>
            /// The Google Ads customer ID for which the call is made.
            /// </summary>
            [Option("customerId", Required = true, HelpText =
                "The Google Ads customer ID for which the call is made.")]
            public long CustomerId { get; set; }
        }

        /// <summary>
        /// Main method, to run this code example as a standalone application.
        /// </summary>
        /// <param name="args">The command line arguments.</param>
        public static void Main(string[] args)
        {
            Options options = ExampleUtilities.ParseCommandLine<Options>(args);

            AddCustomGrpcInterceptor codeExample = new AddCustomGrpcInterceptor();
            Console.WriteLine(codeExample.Description);
            GoogleAdsClient client = new GoogleAdsClient();
            // Add a custom interceptor.
            client.AddInterceptor(new CustomInterceptor());
            codeExample.Run(client,
                options.CustomerId);
        }

        /// <summary>
        /// Returns a description about the code example.
        /// </summary>
        public override string Description =>
            "This code example shows how to add a custom gRPC interceptor.";

        /// <summary>
        /// Runs the code example.
        /// </summary>
        /// <param name="client">The Google Ads client.</param>
        /// <param name="customerId">The Google Ads customer ID for which the call is made.</param>
        public void Run(GoogleAdsClient client, long customerId)
        {
            // Get the GoogleAdsService.
            GoogleAdsServiceClient googleAdsService = client.GetService(
                Services.V16.GoogleAdsService);

            // Create a query that will retrieve all campaigns, just to demonstrate usage of the
            // custom interceptor.
            string query = @"SELECT
                            campaign.id,
                        FROM campaign
                        ORDER BY campaign.id";

            try
            {
                // Issue a streaming search request; we don't need to do anything with the response
                // here, we just want to demonstrate usage of the interceptor.
                googleAdsService.SearchStream(customerId.ToString(), query,
                    delegate (SearchGoogleAdsStreamResponse resp){}
                );
            }
            catch (GoogleAdsException e)
            {
                Console.WriteLine("Failure:");
                Console.WriteLine($"Message: {e.Message}");
                Console.WriteLine($"Failure: {e.Failure}");
                Console.WriteLine($"Request ID: {e.RequestId}");
                throw;
            }
            try
            {
                // Issue a non-streaming call.
                PagedEnumerable<SearchGoogleAdsResponse, GoogleAdsRow> response =
                    googleAdsService.Search(customerId.ToString(), query);
                foreach (GoogleAdsRow googleAdsRow in response)
                {
                    // The response for Search is lazy, meaning that the actual gRPC call will be
                    // sent only when the response is actually accessed; to demonstrate usage of
                    // the interceptor, then, we need to ensure the call is sent by looping
                    // through the response results.
                    Console.WriteLine("Campaign with ID {0} was found.",
                        googleAdsRow.Campaign.Id, googleAdsRow.Campaign.Name);
                }
            }
            catch (GoogleAdsException e)
            {
                Console.WriteLine("Failure:");
                Console.WriteLine($"Message: {e.Message}");
                Console.WriteLine($"Failure: {e.Failure}");
                Console.WriteLine($"Request ID: {e.RequestId}");
                throw;
            }
        }
    }

    /// <summary>
    /// A custom interceptor for both streaming and non-streaming gRPC calls.
    /// </summary>
    internal class CustomInterceptor : Interceptor
    {

        public override AsyncUnaryCall<TResponse> AsyncUnaryCall<TRequest, TResponse>(
            TRequest request, ClientInterceptorContext<TRequest, TResponse> context,
            AsyncUnaryCallContinuation<TRequest, TResponse> continuationCallback)
        {
            AsyncUnaryCall<TResponse> call = continuationCallback(request, context);

            Action<Task<TResponse>> callback = delegate (Task<TResponse> oldTask)
            {
                Console.WriteLine($"Intercepted a non-streaming call to {context.Method.Name}");
            };

            return UnaryRpcInterceptor.Intercept(call, callback);
        }

        public override AsyncServerStreamingCall<TResponse> AsyncServerStreamingCall<TRequest, TResponse>(
            TRequest request, ClientInterceptorContext<TRequest, TResponse> context,
            AsyncServerStreamingCallContinuation<TRequest, TResponse> continuation)
        {
            AsyncServerStreamingCall<TResponse> call = continuation(request, context);
            StreamingRpcInterceptor<TResponse> responseStream = null;

            responseStream = new StreamingRpcInterceptor<TResponse>(call.ResponseStream,
                delegate (TResponse response, AggregateException rpcException)
                {
                    Console.WriteLine($"Intercepted a streaming call to {context.Method.Name}");
                });

            return new AsyncServerStreamingCall<TResponse>(
                responseStream,
                call.ResponseHeadersAsync,
                call.GetStatus,
                call.GetTrailers,
                call.Dispose
            );
        }
    }
}