src/ReverseProxy/Configuration/IYarpOutputCachePolicyProvider.cs - main - aprogrammer/reverse-proxy-ms-yarp

src/ReverseProxy/Configuration/IYarpOutputCachePolicyProvider.cs

55 строк2 KB

witskeeper

Add OutputCachePolicy support (#2328)

28 ноя 2023, 19:09

28 ноя 2023, 19:093853af1

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

#if NET7_0_OR_GREATER
using System;
using System.Collections;
using System.Reflection;
using Microsoft.AspNetCore.OutputCaching;
using Microsoft.Extensions.Options;
#endif

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

namespace Yarp.ReverseProxy.Configuration;

// TODO: update or remove this once AspNetCore provides a mechanism to validate the OutputCache policies https://github.com/dotnet/aspnetcore/issues/52419

internal interface IYarpOutputCachePolicyProvider
{
    ValueTask<object?> GetPolicyAsync(string policyName);
}

internal class YarpOutputCachePolicyProvider : IYarpOutputCachePolicyProvider
{
#if NET7_0_OR_GREATER
    private readonly OutputCacheOptions _outputCacheOptions;

    private readonly IDictionary _policyMap;

    public YarpOutputCachePolicyProvider(IOptions<OutputCacheOptions> outputCacheOptions)
    {
        _outputCacheOptions = outputCacheOptions?.Value ?? throw new ArgumentNullException(nameof(outputCacheOptions));

        var type = typeof(OutputCacheOptions);
        var flags = BindingFlags.Instance | BindingFlags.NonPublic;
        var proprety = type.GetProperty("NamedPolicies", flags);
        if (proprety == null || !typeof(IDictionary).IsAssignableFrom(proprety.PropertyType))
        {
            throw new NotSupportedException("This version of YARP is incompatible with the current version of ASP.NET Core.");
        }
        _policyMap = (proprety.GetValue(_outputCacheOptions, null) as IDictionary) ?? new Dictionary<string, object>();
    }

    public ValueTask<object?> GetPolicyAsync(string policyName)
    {
        return ValueTask.FromResult(_policyMap[policyName]);
    }
#else
    public ValueTask<object?> GetPolicyAsync(string policyName)
    {
        return default;
    }
#endif
}