首页 > 解决方案 > 使用 Servicestack,在使用带有 ServiceSource 的 AutoQuery 时如何缓存结果集?

问题描述

我正在尝试将 ServiceStack 的 AutoQuery 与服务源一起使用,但要么无法使缓存正常工作,要么误解了它应该如何工作。

我试图实现将查询功能添加到“边缘”微服务,该微服务调用提供完整数据列表的内部服务。

重现我的问题的最少代码:

class Program
{
    static async Task Main(string[] args)
    {
        IWebHost host = new WebHostBuilder()
            .UseKestrel((builderContext, options) => options.Configure(builderContext.Configuration.GetSection("Kestrel")))
            .UseStartup<Startup>()
            .Build();
        await host.RunAsync();
    }
}

public class Startup
{
    public void ConfigureServices(IServiceCollection services) {}
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseServiceStack(new AppHost());
        app.Run(context => Task.FromResult(0));
    }
}

public class AppHost : AppHostBase
{
    public AppHost() : base("Hello Web Services", typeof(HelloService).Assembly){ }

    public override void Configure(Funq.Container container)
    {
        container.AddSingleton<ICacheClient, MemoryCacheClient>(); // Otherwise HostContext.Cache is null
        Plugins.Add(new AutoQueryDataFeature { MaxLimit = 3, IncludeTotal = true }.AddDataSource(ctx => ctx.ServiceSource<string>(new Hello(), HostContext.Cache, TimeSpan.FromMinutes(5))));
    }
}

// Request DTO
[Route("/hello")]
[Route("/hello/{Name}")]
public class Hello : QueryData<NameDto>
{
    [QueryDataField(Condition = "StartsWith", Field = nameof(Name))]
    public string Name { get; set; }
}

public class NameDto
{
    public string Name { get; set; }
}

public class HelloService : Service
{
    public IAutoQueryData AutoQuery { get; set; }
    public async Task<object> Any(Hello query)
    {
        //Imagine I was making a service call to another microservice here...
        var data = new List<NameDto> { new NameDto { Name = "Bob" }, new NameDto { Name = "George" }, new NameDto { Name = "Baldrick" }, new NameDto { Name = "Nursey" }, new NameDto { Name = "Melchett" }, new NameDto { Name = "Kate" } };

        DataQuery<NameDto> dataQuery = AutoQuery.CreateQuery(query, Request, new MemoryDataSource<NameDto>(data, query, Request));

        return AutoQuery.Execute(query, dataQuery);
    }
}   

Nuget 包:Mircosoft.AspNetCore.All (2.2.1) 和 ServiceStack (5.4.0)

因此,在控制台 (.NET Core 2.2) 中,上述代码将启动并侦听端口 5000。

如果我查询,我得到我的列表,它按预期限制了结果的数量,我也可以按预期跳过/采取。

但是,每次我调用服务方法时,结果都不会被缓存(这是我注册插件时指定的 - 缓存 5 分钟),如果我在服务方法中放置断点,“名称”列表是每次都重新创建。即使我向服务提出相同的请求,也会发生这种情况。

我希望能够缓存结果集(在内存中很好),并且只有在缓存过期时才点击服务方法。我在这里做错了什么(或误解)?

编辑

我曾经尝试过 Mythz 建议的代码......现在我根本没有任何自动查询功能可用。

class Program
{
    static async Task Main(string[] args)
    {
        IWebHost host = new WebHostBuilder()
            .UseKestrel((builderContext, options) => options.Configure(builderContext.Configuration.GetSection("Kestrel")))
            .UseStartup<Startup>()
            .Build();
        await host.RunAsync();
    }
}

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
    }
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseServiceStack(new AppHost());
        app.Run(context => Task.FromResult(0));
    }
}

public class AppHost : AppHostBase
{
    public AppHost() : base("Hello Web Services", typeof(HelloService).Assembly){ }

    public override void Configure(Funq.Container container)
    {
        container.AddSingleton<ICacheClient, MemoryCacheClient>();

        Plugins.Add(new AutoQueryDataFeature { MaxLimit = 5 }
            .AddDataSource(ctx => ctx.ServiceSource<GithubRepo>(ctx.Dto.ConvertTo<QueryGithubRepo>(),
                HostContext.Cache, TimeSpan.FromMinutes(5))));
    }


}


public class QueryGithubRepo : QueryData<GithubRepo>
{
    public string User { get; set; }
    public string Organization { get; set; }
}

public class GithubRepo
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public string Homepage { get; set; }
    public int Watchers_Count { get; set; }
    public int Stargazers_Count { get; set; }
    public int Size { get; set; }
    public string Full_Name { get; set; }
    public DateTime Created_at { get; set; }
    public DateTime? Updated_At { get; set; }

    public bool Has_Downloads { get; set; }
    public bool Fork { get; set; }

    public string Url { get; set; } // https://api.github.com/repos/NetCoreWebApps/bare
    public string Html_Url { get; set; }
    public bool Private { get; set; }

    public GithubRepo Parent { get; set; } // only on single result, e.g: /repos/NetCoreWebApps/bare
}

public class NameDto
{
    public string Name { get; set; }
}

public class HelloService : Service
{    
    public object Get(QueryGithubRepo request)
    {
        if (request.User == null && request.Organization == null)
            throw new ArgumentNullException("User");

        var url = request.User != null
            ? $"https://api.github.com/users/{request.User}/repos"
            : $"https://api.github.com/orgs/{request.Organization}/repos";

        return url.GetJsonFromUrl(requestFilter: req => req.UserAgent = GetType().Name)
            .FromJson<List<GithubRepo>>();
    }
}

标签: c#caching.net-coreservicestackservicestack-autoquery

解决方案


如果您在服务实现中使用 AutoQuery,那只是自定义 AutoQuery 实现,而不是查询普通服务结果的AutoQuery 服务数据源。

在这种情况下,听起来您确实想要一个可缓存的自动查询服务数据源,文档在其GetGithubRepos 服务中显示了一个示例,该服务对 GitHub 的第 3 方 API 进行 API 调用:

public class QueryGithubRepo : QueryData<GithubRepo> 
{
    public string User { get; set; }
    public string Organization { get; set; }
}

public object Get(GetGithubRepos request)
{
    if (request.User == null && request.Organization == null)
        throw new ArgumentNullException("User");

    var url = request.User != null
        ? $"https://api.github.com/users/{request.User}/repos"
        : $"https://api.github.com/orgs/{request.Organization}/repos";

    return url.GetJsonFromUrl(requestFilter:req => req.UserAgent = GetType().Name)
        .FromJson<List<GithubRepo>>();
}

然后在注册Service DataSource时注册它是一个缓存的Service DataSource:

Plugins.Add(new AutoQueryDataFeature { MaxLimit = 100 }
    .AddDataSource(ctx => ctx.ServiceSource<GithubRepo>(ctx.Dto.ConvertTo<GetGithubRepos>(), 
        HostContext.Cache, TimeSpan.FromMinutes(5)));
);

您可以使用HostContext.LocalCache将其缓存在本地内存缓存中,而不是注册的ICacheClient 缓存提供程序


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