asp.net core 使用protobuf

時間 2019-11-24

標籤 asp.net asp core 使用 protobuf 欄目 ASP 简体版

原文原文鏈接

在一些性能要求很高的應用中，使用protocol buffer序列化，優於Json。並且protocol buffer向後兼容的能力比較好。git

因爲Asp.net core 採用了全新的MiddleWare方式，所以使用protobuf序列化，只須要使用Protobuf-net修飾須要序列化的對象，並在MVC初始化的時候增長相應的Formatter就能夠了。github

MVC Controller 的Action返回對象時，MVC回根據用戶的Request Header裏面的MIME選擇對應的Formater來序列化返回對象( Serialize returned object)。MVC具備默認的Json Formater，這個能夠不用管。數據庫

這裏有一個直接能夠運行的例子，具備Server和Client代碼 https://github.com/damienbod/AspNetMvc6ProtobufFormattersjson

可是，這裏面有一個很嚴重的問題。看下面的例子。app

例如咱們須要序列化的對象時ApparatusType，服務端的定義(使用了EntityFramework)是這樣的：async

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using ProtoBuf;

namespace Hammergo.Data
{

    [ProtoContract]
    public partial class ApparatusType
    {
        public ApparatusType()
        {
            this.Apps = new List<App>();
        }

        [ProtoMember(1)]
        public System.Guid Id { get; set; }

        [ProtoMember(2)]
        [MaxLength(20)]
        public string TypeName { get; set; }
        [ProtoIgnore]
        public virtual ICollection<App> Apps { get; set; }
    }
}

屬於ProtoBuf 的三個修飾爲ide

 [ProtoContract]

 [ProtoMember(1)]

 [ProtoMember(2)]
其餘的不用管，在客戶端定義是這樣的

using System;
using System.Collections.Generic;
using ProtoBuf;

namespace Hammergo.Poco
{

    [ProtoContract]
    public class ApparatusType
    {

        [ProtoMember(1)]
        public virtual System.Guid Id { get; set; }

        [ProtoMember(2)]
        public virtual string TypeName { get; set; }
    }
}

這裏使用了Virtual關鍵字，是爲了生成POCO的代理類，以跟蹤狀態，沒有這個要求能夠不使用。性能

若是使用https://github.com/damienbod/AspNetMvc6ProtobufFormatters 的方案就會發現測試

若是ASP.NET 的action返回List<AppratusType>，在客戶端使用ui

  var result = response.Content.ReadAsAsync<List<Hammergo.Poco.ApparatusType>>(new[] { new ProtoBufFormatter() }).Result;

就會拋出異常，ReadAsAsync ProtoBuf Formatter No MediaTypeFormatter is available to read

大意是沒有相應的MediaTypeFormatter來供ReadAsAsync來使用，

檢查https://github.com/damienbod/AspNetMvc6ProtobufFormatters 的方案，發現它調用了https://github.com/WebApiContrib/WebApiContrib.Formatting.ProtoBuf裏面的ProtoBufFormatter.cs ，這個裏面有一個錯誤。

using System;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Formatting;
using System.Net.Http.Headers;
using System.Reflection;
using System.Threading.Tasks;
using ProtoBuf;
using ProtoBuf.Meta;

namespace WebApiContrib.Formatting
{
    public class ProtoBufFormatter : MediaTypeFormatter
    {
        private static readonly MediaTypeHeaderValue mediaType = new MediaTypeHeaderValue("application/x-protobuf");
        private static Lazy<RuntimeTypeModel> model = new Lazy<RuntimeTypeModel>(CreateTypeModel);

        public static RuntimeTypeModel Model
        {
            get { return model.Value; }
        }

        public ProtoBufFormatter()
        {
            SupportedMediaTypes.Add(mediaType);
        }

        public static MediaTypeHeaderValue DefaultMediaType
        {
            get { return mediaType; }
        }

        public override bool CanReadType(Type type)
        {
            return CanReadTypeCore(type);
        }

        public override bool CanWriteType(Type type)
        {
            return CanReadTypeCore(type);
        }

        public override Task<object> ReadFromStreamAsync(Type type, Stream stream, HttpContent content, IFormatterLogger formatterLogger)
        {
            var tcs = new TaskCompletionSource<object>();

            try
            {
                object result = Model.Deserialize(stream, null, type);
                tcs.SetResult(result);
            }
            catch (Exception ex)
            {
                tcs.SetException(ex);
            }

            return tcs.Task;
        }

        public override Task WriteToStreamAsync(Type type, object value, Stream stream, HttpContent content, TransportContext transportContext)
        {
            var tcs = new TaskCompletionSource<object>();

            try
            {
                Model.Serialize(stream, value);
                tcs.SetResult(null);
            }
            catch (Exception ex)
            {
                tcs.SetException(ex);
            }

            return tcs.Task;
        }

        private static RuntimeTypeModel CreateTypeModel()
        {
            var typeModel = TypeModel.Create();
            typeModel.UseImplicitZeroDefaults = false;
            return typeModel;
        }

        private static bool CanReadTypeCore(Type type)
        {
            return type.GetCustomAttributes(typeof(ProtoContractAttribute)).Any();
        }
    }
}

private static bool CanReadTypeCore(Type type)這個有問題，它只能識別有ProtoContract的類，無法識別其對應的IEnumerable<T>，修改這個方法就能夠了。以下：

        private static bool CanReadTypeCore(Type type)
        {
            bool isCan = type.GetCustomAttributes(typeof(ProtoContractAttribute)).Any();

            if (!isCan && typeof(IEnumerable).IsAssignableFrom(type))
            {
                var temp = type.GetGenericArguments().FirstOrDefault();
                isCan = temp.GetCustomAttributes(typeof(ProtoContractAttribute)).Any();
            }

            return isCan;
        }

下面我給出，關鍵的代碼片斷：

使用了一個輔助Library，結構以下圖：

DateTimeOffsetSurrogate.cs的代碼以下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using ProtoBuf;

namespace ProtoBufHelper
{

    [ProtoContract]
    public class DateTimeOffsetSurrogate
    {
        [ProtoMember(1)]
        public long DateTimeTicks { get; set; }
        [ProtoMember(2)]
        public short OffsetMinutes { get; set; }

        public static implicit operator DateTimeOffsetSurrogate(DateTimeOffset value)
        {
            return new DateTimeOffsetSurrogate
            {
                DateTimeTicks = value.Ticks,
                OffsetMinutes = (short)value.Offset.TotalMinutes
            };
        }

        public static implicit operator DateTimeOffset(DateTimeOffsetSurrogate value)
        {
            return new DateTimeOffset(value.DateTimeTicks, TimeSpan.FromMinutes(value.OffsetMinutes));
        }
    }
}

ProtoBufFormatter.cs 的代碼以下：

using System;
using System.Collections;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Formatting;
using System.Net.Http.Headers;
using System.Reflection;
using System.Threading.Tasks;
using ProtoBuf;
using ProtoBuf.Meta;

namespace ProtoBufHelper
{
    public class ProtoBufFormatter : MediaTypeFormatter
    {
        private static readonly MediaTypeHeaderValue mediaType = new MediaTypeHeaderValue("application/x-protobuf");
        private static Lazy<RuntimeTypeModel> model = new Lazy<RuntimeTypeModel>(CreateTypeModel);

        public static RuntimeTypeModel Model
        {
            get { return model.Value; }
        }

        public ProtoBufFormatter()
        {
            SupportedMediaTypes.Add(mediaType);
        }

        public static MediaTypeHeaderValue DefaultMediaType
        {
            get { return mediaType; }
        }

        public override bool CanReadType(Type type)
        {
            var temp = CanReadTypeCore(type);
            return temp;
        }

        public override bool CanWriteType(Type type)
        {
            return CanReadTypeCore(type);
        }

        public override Task<object> ReadFromStreamAsync(Type type, Stream stream, HttpContent content, IFormatterLogger formatterLogger)
        {
            var tcs = new TaskCompletionSource<object>();

            try
            {
                object result = Model.Deserialize(stream, null, type);
                tcs.SetResult(result);
            }
            catch (Exception ex)
            {
                tcs.SetException(ex);
            }

            return tcs.Task;
        }

        public override Task WriteToStreamAsync(Type type, object value, Stream stream, HttpContent content, TransportContext transportContext)
        {
            var tcs = new TaskCompletionSource<object>();

            try
            {
                Model.Serialize(stream, value);
                tcs.SetResult(null);
            }
            catch (Exception ex)
            {
                tcs.SetException(ex);
            }

            return tcs.Task;
        }

        private static RuntimeTypeModel CreateTypeModel()
        {
            var typeModel = TypeModel.Create();
            typeModel.UseImplicitZeroDefaults = false;
            typeModel.Add(typeof(DateTimeOffset), false).SetSurrogate(typeof(DateTimeOffsetSurrogate));
            return typeModel;
        }

        private static bool CanReadTypeCore(Type type)
        {
            bool isCan = type.GetCustomAttributes(typeof(ProtoContractAttribute)).Any();

            if (!isCan && typeof(IEnumerable).IsAssignableFrom(type))
            {
                var temp = type.GetGenericArguments().FirstOrDefault();
                isCan = temp.GetCustomAttributes(typeof(ProtoContractAttribute)).Any();
            }

            return isCan;
        }
    }
}

這樣就能夠設置ASP.NET Core端的代碼：

添加ProtobufInputFormatter.cs 和 ProtobufOutputFormatter.cs 代碼分別以下：

using System;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Formatters;
using Microsoft.Net.Http.Headers;
using ProtoBuf.Meta;
using ProtoBufHelper;

namespace DamService
{
    public class ProtobufInputFormatter : InputFormatter
    {
        private static Lazy<RuntimeTypeModel> model = new Lazy<RuntimeTypeModel>(CreateTypeModel);

        public static RuntimeTypeModel Model
        {
            get { return model.Value; }
        }

        public override Task<InputFormatterResult> ReadRequestBodyAsync(InputFormatterContext context)
        {
            var type = context.ModelType;
            var request = context.HttpContext.Request;
            MediaTypeHeaderValue requestContentType = null;
            MediaTypeHeaderValue.TryParse(request.ContentType, out requestContentType);


            object result = Model.Deserialize(context.HttpContext.Request.Body, null, type);
            return InputFormatterResult.SuccessAsync(result);
        }

        public override bool CanRead(InputFormatterContext context)
        {
            return true;
        }


        private static RuntimeTypeModel CreateTypeModel()
        {
            var typeModel = TypeModel.Create();
            typeModel.UseImplicitZeroDefaults = false;

            typeModel.Add(typeof(DateTimeOffset), false).SetSurrogate(typeof(DateTimeOffsetSurrogate));
            return typeModel;
        }
    }
}

using System;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc.Formatters;
using Microsoft.Net.Http.Headers;
using ProtoBuf.Meta;
using ProtoBufHelper;

namespace DamService
{
    public class ProtobufOutputFormatter :  OutputFormatter
    {
        private static Lazy<RuntimeTypeModel> model = new Lazy<RuntimeTypeModel>(CreateTypeModel);

        public string ContentType { get; private set; }

        public static RuntimeTypeModel Model
        {
            get { return model.Value; }
        }

        public ProtobufOutputFormatter()
        {
            ContentType = "application/x-protobuf";
            SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("application/x-protobuf"));

            //SupportedEncodings.Add(Encoding.GetEncoding("utf-8"));
        }

        private static RuntimeTypeModel CreateTypeModel()
        {
            var typeModel = TypeModel.Create();
            typeModel.UseImplicitZeroDefaults = false;
            typeModel.Add(typeof(DateTimeOffset), false).SetSurrogate(typeof(DateTimeOffsetSurrogate));
            return typeModel;
        }

        public override Task WriteResponseBodyAsync(OutputFormatterWriteContext context)
        {
            var response = context.HttpContext.Response;
    
            Model.Serialize(response.Body, context.Object);
            return Task.FromResult(response);
        }
    }
}

在Startup.cs中

public void ConfigureServices(IServiceCollection services) 方法中這樣添加MVC中間件

services.AddMvc(options =>
{
options.InputFormatters.Add(new ProtobufInputFormatter());
options.OutputFormatters.Add(new ProtobufOutputFormatter());
options.FormatterMappings.SetMediaTypeMappingForFormat("protobuf", MediaTypeHeaderValue.Parse("application/x-protobuf"));
});

整個Startup.cs代碼

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using DamService.Data;
using DamService.Models;
using DamService.Services;
using System.Net;
using Microsoft.AspNetCore.Diagnostics;
using Microsoft.AspNetCore.Http;
using Microsoft.Net.Http.Headers;

namespace DamService
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true);

            if (env.IsDevelopment())
            {
                // For more details on using the user secret store see http://go.microsoft.com/fwlink/?LinkID=532709
                builder.AddUserSecrets();
            }

            builder.AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        public IConfigurationRoot Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddDbContext<ApplicationDbContext>(options =>
                options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

            services.AddScoped(provider => new Hammergo.Data.DamWCFContext(Configuration.GetConnectionString("OdataDBConnectionString")));

            services.AddIdentity<ApplicationUser, IdentityRole>()
                .AddEntityFrameworkStores<ApplicationDbContext>()
                .AddDefaultTokenProviders();

            services.AddMvc(options =>
            {
                options.InputFormatters.Add(new ProtobufInputFormatter());
                options.OutputFormatters.Add(new ProtobufOutputFormatter());
                options.FormatterMappings.SetMediaTypeMappingForFormat("protobuf", MediaTypeHeaderValue.Parse("application/x-protobuf"));
            });


            // Add application services.
            //services.AddTransient<IEmailSender, AuthMessageSender>();
            //services.AddTransient<ISmsSender, AuthMessageSender>();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();

            //if (env.IsDevelopment())
            //{
            //    app.UseDeveloperExceptionPage();
            //    app.UseDatabaseErrorPage();
            //    app.UseBrowserLink();
            //}
            //else
            //{
            //    app.UseExceptionHandler("/Home/Error");
            //}

            app.UseExceptionHandler(_exceptionHandler);

            app.UseStaticFiles();

            app.UseIdentity();

            // Add external authentication middleware below. To configure them please see http://go.microsoft.com/fwlink/?LinkID=532715

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
            });
        }

        private void _exceptionHandler(IApplicationBuilder builder)
        {
            builder.Run(
              async context =>
                 {
                     context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
                     context.Response.ContentType = "text/plain";

                     var error = context.Features.Get<IExceptionHandlerFeature>();
                     if (error != null)
                     {
                         await context.Response.WriteAsync(error.Error.Message).ConfigureAwait(false);
                     }
                 });
        }
    }
}

　　上面的

services.AddScoped(provider => new Hammergo.Data.DamWCFContext(Configuration.GetConnectionString("OdataDBConnectionString")));是我本身的數據庫鏈接，可使用本身的，也能夠不用，我用的是EntityFrameWork 6.1.3 不是core，目前core還有一些功能沒有，暫時不使用。

 添加一個測試用的Controller，

using System;
using System.Linq;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Hammergo.Data;
using System.Linq.Expressions;
using System.Data.Entity;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace DamService.Controllers
{
    public class AppsController : Controller
    {
        private readonly DamWCFContext _dbContext;
        private readonly ILogger _logger;

        public AppsController(
           DamWCFContext dbContext,
        ILoggerFactory loggerFactory)
        {
            _dbContext = dbContext;
            _logger = loggerFactory.CreateLogger<AccountController>();
        }

        [HttpGet]
        public async Task<List<App>> Top10()
        {
            return await _dbContext.Apps.Take(10).ToListAsync();
        }

    }
}

客戶端測試代碼：

            var client = new HttpClient { BaseAddress = new Uri("http://localhost.Fiddler:40786/") };
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/x-protobuf"));

            HttpResponseMessage response = null;

            //test top 10
            string uri = "Apps/Top10";
            Trace.WriteLine("\n Test {0}.", uri);
            response = client.GetAsync(uri).Result;

            if (response.IsSuccessStatusCode)
            {
                var result = response.Content.ReadAsAsync<List<Hammergo.Poco.App>>(new[] { new ProtoBufFormatter() }).Result;

                Assert.AreEqual(result.Count, 10, "反序列化失敗");

               
                Console.WriteLine("{0} test success!", uri);
            }
            else
            {
                var message = response.Content.ReadAsStringAsync().Result;
                Console.WriteLine("{0} ({1})\n message: {2} ", (int)response.StatusCode, response.ReasonPhrase, message);
            }

http://localhost.Fiddler:40786/  這裏40786爲服務端口，Fiddler表示使用了Fiddler代理，這樣在使用時須要開啓Fiddler，若是不使用Fidller，將URI修改成：

http://localhost:40786/

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