一、截止時間概述

1. 截止時間功能讓 gRPC 客戶端可以指定等待調(diào)用完成的時間。
2. ?超過截止時間時，將取消調(diào)用。
3. ?設(shè)定一個截止時間非常重要，因為它將提供調(diào)用可運行的最長時間。
4. 它能阻止異常運行的服務(wù)持續(xù)運行并耗盡服務(wù)器資源。
5. 截止時間對于構(gòu)建可靠應(yīng)用非常有效，應(yīng)該進行配置。

二、取消概述

1. 客戶端主動取消不再需要長期運行的調(diào)用
2. 線程故障自動取消
3. 超出截止時間觸發(fā)取消操作

三、實戰(zhàn)案例

1. 首先準備一個grpc后端服務(wù)
2. 其次準備一個webapi服務(wù)作為客戶端，方便HttpContext傳遞
3. 客戶端工廠配置EnableCallContextPropagation 用于上下文傳遞截止時間
4. 傳遞CancellationTokenSource
5. 話不多說，通過代碼可以更好的看出程序的運行軌跡

// 引入proto文件
// 公共messages.protosyntax = "proto3";option csharp_namespace = "GrpcProject";package grpc.serviceing;// 請求體
message ServerRequest{string name = 1;double height = 2;int32 age = 3;bool flag = 4;float x = 5;float y = 6;float z= 7;repeated string departments = 8;
}message ServerFileRequest{bytes fileBytes = 1;
}// 響應(yīng)體
message ServerResponse{bool result = 1;
}// 服務(wù)dollar.proto文件syntax = "proto3";import "google/protobuf/empty.proto";
import "Protos/messages.proto";option csharp_namespace = "GrpcProject";package grpc.serviceing;service DollarRpc{rpc ServerOne (ServerRequest) returns (ServerResponse);rpc ServerTwo (ServerRequest) returns (google.protobuf.Empty);
}

服務(wù)端接口實現(xiàn)：

   public class DollarService : DollarRpc.DollarRpcBase{public override async Task<ServerResponse> ServerOne(ServerRequest request, ServerCallContext context){await Console.Out.WriteLineAsync("-------------------------ServerOne------------------------------\r\n");await Task.Delay(TimeSpan.FromSeconds(8), context.CancellationToken);foreach (var prop in request.GetType().GetProperties()){await Console.Out.WriteLineAsync($"property  name：{prop.Name}；value：{prop.GetValue(request)}");}return GetResponse();}public override async Task<Empty> ServerTwo(ServerRequest request, ServerCallContext context){await Console.Out.WriteLineAsync("-------------------------ServerTwo------------------------------\r\n");await Task.Delay(TimeSpan.FromSeconds(8), context.CancellationToken);foreach (var prop in request.GetType().GetProperties()){await Console.Out.WriteLineAsync($"property  name：{prop.Name}；value：{prop.GetValue(request)}");}return new();}private ServerResponse GetResponse() => new() { Result = true };}

客戶端實現(xiàn)重點：

1. program注入客戶端工廠并啟用截止時間配置
2. 增加攔截器統(tǒng)一設(shè)定超時時間
3. 調(diào)用查看結(jié)果

// program.csbuilder.Services.AddGrpcClient<DollarRpc.DollarRpcClient>(options =>
{options.Address = new Uri("https://localhost:7188");
}).EnableCallContextPropagation();

//攔截器過濾截止時間[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = false)]public class GrpcFilterAttribute : Attribute, IActionFilter{public void OnActionExecuted(ActionExecutedContext context){}public void OnActionExecuting(ActionExecutingContext context){CancellationTokenSource tokenSource = new();GrpcServerCallContextFeature callContext = new(DateTime.UtcNow.AddSeconds(5), tokenSource.Token);context.HttpContext.Features.Set<IServerCallContextFeature>(callContext);}}public class GrpcServerCallContextFeature : ServerCallContext, IServerCallContextFeature{/// <summary>/// 構(gòu)造/// </summary>/// <param name="deadline"></param>/// <param name="cancellationToken"></param>public GrpcServerCallContextFeature(DateTime deadline, CancellationToken cancellationToken){DeadlineCore = deadline;CancellationTokenCore = cancellationToken;AuthContextCore = new AuthContext(null, new Dictionary<string, List<AuthProperty>>());}public ServerCallContext ServerCallContext => this;protected override string MethodCore { get; }protected override string HostCore { get; }protected override string PeerCore { get; }protected override DateTime DeadlineCore { get; }protected override Metadata RequestHeadersCore { get; }protected override CancellationToken CancellationTokenCore { get; }protected override Metadata ResponseTrailersCore { get; }protected override Status StatusCore { get; set; }protected override WriteOptions? WriteOptionsCore { get; set; }protected override AuthContext AuthContextCore { get; }protected override ContextPropagationToken CreatePropagationTokenCore(ContextPropagationOptions? options){return base.CreatePropagationToken(options);}protected override Task WriteResponseHeadersAsyncCore(Metadata responseHeaders){throw new NotImplementedException();}}

//調(diào)用
// 在相應(yīng)的類上打上標記   [GrpcFilter][Route("api/[controller]")][ApiController][GrpcFilter] // 設(shè)定截止時間過濾public class GrpcTestController : ControllerBase{private readonly DollarRpc.DollarRpcClient _dollarRpcClient;public GrpcTestController(DollarRpc.DollarRpcClient dollarRpcClient) => _dollarRpcClient = dollarRpcClient;[HttpGet("one")]public async Task<string> GetOneResult(){ServerRequest request = new ServerRequest(){Departments = {"one","two","three","four","five"},Age = 10,Flag = true,Height = 10,Name = "zhangsan",X = 10F,Y = 11F,Z = 12F};try{var response = await _dollarRpcClient.ServerOneAsync(request);if (response.Result){return "Success";}return "Fail";}catch (RpcException ex) when (ex.StatusCode == Grpc.Core.StatusCode.DeadlineExceeded){return "dealine timeout.";}catch (RpcException ex){return ($"NoResult：{ex.Message}");}}[HttpGet("two")]public async Task<string> GetTwoResult(){ServerRequest request = new ServerRequest(){Departments = {"one","two","three","four","five"},Age = 10,Flag = true,Height = 10,Name = "zhangsan",X = 10F,Y = 11F,Z = 12F};try{var response = await _dollarRpcClient.ServerTwoAsync(request);return "Success";}catch (RpcException ex) when (ex.StatusCode == Grpc.Core.StatusCode.DeadlineExceeded){return "dealine timeout.";}catch (RpcException ex){return ($"NoResult：{ex.Message}");}}}

四、查看執(zhí)行結(jié)果

服務(wù)端One：

客戶端One：

?

?swagger:

?另一個Two效果類似。同時服務(wù)端任務(wù)取消錯誤，也在截圖上有顯示。

五、源碼地址

鏈接：https://pan.baidu.com/s/1vleChFc3F6ILs-5ad8xQCA?
提取碼：mud0