Benutzerdefinierte gRPC-Interceptors

Die .NET-Clientbibliothek verwendet intern gRPC-Interceptors für Protokollierungszwecke. Außerdem können Sie Ihre eigenen benutzerdefinierten gRPC-Interceptors registrieren. Weitere Informationen zu Interceptors finden Sie in der Dokumentation zu gRPC-Interceptors. Sie können benutzerdefinierte Interceptors verwenden, um Messwerte in einem benutzerdefinierten Log-Aggregator zu protokollieren, Header zu prüfen oder Google Ads API-Anfragen zu transformieren.

Interceptor implementieren und anhängen

Wenn Sie einen benutzerdefinierten gRPC-Interceptor hinzufügen möchten, implementieren Sie eine Klasse, die die Grpc.Core.Interceptors.Interceptor Basisklasse erweitert (aus dem Grpc.Core.Api Paket, das von den Transporten Grpc.Net.Client und Grpc.Core unterstützt wird), und hängen Sie sie mit der Methode AddInterceptor an Ihren GoogleAdsClient an. Wenn Sie mehrere Interceptors registrieren, werden sie in der Reihenfolge ausgeführt, in der sie hinzugefügt wurden.

Der Namespace Google.Ads.Gax.Interceptors enthält Hilfsklassen, die in benutzerdefinierten Interceptors verwendet werden können, um die Ausnahmebehandlung zu erleichtern.

Codebeispiel

Im folgenden Codebeispiel werden sowohl ein Streaming- als auch ein Nicht-Streaming-gRPC-Aufruf-Interceptor implementiert:

// 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.V25.Errors;
using Google.Ads.GoogleAds.V25.Services;
using Grpc.Core;
using Grpc.Core.Interceptors;
using System;

using System.Threading.Tasks;

namespace Google.Ads.GoogleAds.Examples.V25
{
    /// <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.V25.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
            );
        }
    }
}