HybridCache 混合缓存

　　asp.net core 9中，引入了HyBridCache，本质上他并不是全新的一种缓存，而以与原来的缓存复合使用。

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net9.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Caching.StackExchangeRedis" Version="9.0.0-preview.4.24267.6" />
  </ItemGroup>
</Project>

　　下面的例子，time0是内存缓存，time1是基于Redis分布式缓存，time3是混合式缓存。

　　如果说time0，time1是自己当家做主的话，那么tim2就要基于Memory或Distributed缓存了。默认状况下，builder.Services.AddHybridCache是基于内存缓存的，如果想基于别的分布式缓存，只需要添加对应的Service就可以了。

using Microsoft.Extensions.Caching.Distributed;
using Microsoft.Extensions.Caching.Hybrid;
using Microsoft.Extensions.Caching.Memory;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddMemoryCache();

builder.Services.AddStackExchangeRedisCache(opt =>
{
    opt.ConfigurationOptions = new StackExchange.Redis.ConfigurationOptions
    {
        EndPoints = { "localhost:6379" },
        AbortOnConnectFail = false
    };
});
builder.Services.AddHybridCache();

var app = builder.Build();

app.MapGet("/time0", async (IMemoryCache cache) =>
{
    return await cache.GetOrCreateAsync("time0", async _ => await Task.FromResult(DateTime.Now));
});

app.MapGet("/time1", async (IDistributedCache cache) =>
{
    var time = await cache.GetStringAsync("time1");
    if (string.IsNullOrWhiteSpace(time))
    {
        time = DateTime.Now.ToString();
        await cache.SetStringAsync("time1", time);
    }
    return time;
});

app.MapGet("/time2", async (HybridCache cache) =>
{
    return await cache.GetOrCreateAsync("time2", async _ => await Task.FromResult(DateTime.Now));

});
app.Run();