aspnetcore/test/Microsoft.AspNetCore.Respon.../ResponseCachingContextTests.cs

743 lines
28 KiB
C#

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Features;
using Microsoft.AspNetCore.Http.Headers;
using Microsoft.AspNetCore.ResponseCaching.Internal;
using Microsoft.Extensions.Internal;
using Microsoft.Extensions.ObjectPool;
using Microsoft.Extensions.Options;
using Microsoft.Extensions.Primitives;
using Microsoft.Net.Http.Headers;
using Xunit;
namespace Microsoft.AspNetCore.ResponseCaching.Tests
{
public class ResponseCachingContextTests
{
[Fact]
public async Task TryServeFromCacheAsync_OnlyIfCached_Serves504()
{
var cache = new TestResponseCache();
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext, responseCache: cache, keyProvider: new TestKeyProvider());
httpContext.Request.GetTypedHeaders().CacheControl = new CacheControlHeaderValue()
{
OnlyIfCached = true
};
Assert.True(await context.TryServeFromCacheAsync());
Assert.Equal(StatusCodes.Status504GatewayTimeout, httpContext.Response.StatusCode);
}
[Fact]
public async Task TryServeFromCacheAsync_CachedResponseNotFound_Fails()
{
var cache = new TestResponseCache();
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext, responseCache: cache, keyProvider: new TestKeyProvider(new[] { "BaseKey", "BaseKey2" }));
Assert.False(await context.TryServeFromCacheAsync());
Assert.Equal(2, cache.GetCount);
}
[Fact]
public async Task TryServeFromCacheAsync_CachedResponseFound_Succeeds()
{
var cache = new TestResponseCache();
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext, responseCache: cache, keyProvider: new TestKeyProvider(new[] { "BaseKey", "BaseKey2" }));
cache.Set(
"BaseKey2",
new CachedResponse()
{
Body = new byte[0]
},
TimeSpan.Zero);
Assert.True(await context.TryServeFromCacheAsync());
Assert.Equal(2, cache.GetCount);
}
[Fact]
public async Task TryServeFromCacheAsync_VaryRuleFound_CachedResponseNotFound_Fails()
{
var cache = new TestResponseCache();
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext, responseCache: cache, keyProvider: new TestKeyProvider(new[] { "BaseKey", "BaseKey2" }));
cache.Set(
"BaseKey2",
new CachedVaryRules(),
TimeSpan.Zero);
Assert.False(await context.TryServeFromCacheAsync());
Assert.Equal(2, cache.GetCount);
}
[Fact]
public async Task TryServeFromCacheAsync_VaryRuleFound_CachedResponseFound_Succeeds()
{
var cache = new TestResponseCache();
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext, responseCache: cache, keyProvider: new TestKeyProvider(new[] { "BaseKey", "BaseKey2" }, new[] { "VaryKey", "VaryKey2" }));
cache.Set(
"BaseKey2",
new CachedVaryRules(),
TimeSpan.Zero);
cache.Set(
"BaseKey2VaryKey2",
new CachedResponse()
{
Body = new byte[0]
},
TimeSpan.Zero);
Assert.True(await context.TryServeFromCacheAsync());
Assert.Equal(6, cache.GetCount);
}
[Fact]
public void ConditionalRequestSatisfied_NotConditionalRequest_Fails()
{
var context = CreateTestContext(new DefaultHttpContext());
var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
}
[Fact]
public void ConditionalRequestSatisfied_IfUnmodifiedSince_FallsbackToDateHeader()
{
var utcNow = DateTimeOffset.UtcNow;
var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
httpContext.Request.GetTypedHeaders().IfUnmodifiedSince = utcNow;
// Verify modifications in the past succeeds
cachedHeaders.Date = utcNow - TimeSpan.FromSeconds(10);
Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
// Verify modifications at present succeeds
cachedHeaders.Date = utcNow;
Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
// Verify modifications in the future fails
cachedHeaders.Date = utcNow + TimeSpan.FromSeconds(10);
Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
}
[Fact]
public void ConditionalRequestSatisfied_IfUnmodifiedSince_LastModifiedOverridesDateHeader()
{
var utcNow = DateTimeOffset.UtcNow;
var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
httpContext.Request.GetTypedHeaders().IfUnmodifiedSince = utcNow;
// Verify modifications in the past succeeds
cachedHeaders.Date = utcNow + TimeSpan.FromSeconds(10);
cachedHeaders.LastModified = utcNow - TimeSpan.FromSeconds(10);
Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
// Verify modifications at present
cachedHeaders.Date = utcNow + TimeSpan.FromSeconds(10);
cachedHeaders.LastModified = utcNow;
Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
// Verify modifications in the future fails
cachedHeaders.Date = utcNow - TimeSpan.FromSeconds(10);
cachedHeaders.LastModified = utcNow + TimeSpan.FromSeconds(10);
Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
}
[Fact]
public void ConditionalRequestSatisfied_IfNoneMatch_Overrides_IfUnmodifiedSince_ToPass()
{
var utcNow = DateTimeOffset.UtcNow;
var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
var httpContext = new DefaultHttpContext();
var requestHeaders = httpContext.Request.GetTypedHeaders();
var context = CreateTestContext(httpContext);
// This would fail the IfUnmodifiedSince checks
requestHeaders.IfUnmodifiedSince = utcNow;
cachedHeaders.LastModified = utcNow + TimeSpan.FromSeconds(10);
requestHeaders.IfNoneMatch = new List<EntityTagHeaderValue>(new[] { EntityTagHeaderValue.Any });
Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
}
[Fact]
public void ConditionalRequestSatisfied_IfNoneMatch_Overrides_IfUnmodifiedSince_ToFail()
{
var utcNow = DateTimeOffset.UtcNow;
var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
var httpContext = new DefaultHttpContext();
var requestHeaders = httpContext.Request.GetTypedHeaders();
var context = CreateTestContext(httpContext);
// This would pass the IfUnmodifiedSince checks
requestHeaders.IfUnmodifiedSince = utcNow;
cachedHeaders.LastModified = utcNow - TimeSpan.FromSeconds(10);
requestHeaders.IfNoneMatch = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") });
Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
}
[Fact]
public void ConditionalRequestSatisfied_IfNoneMatch_AnyWithoutETagInResponse_Passes()
{
var cachedHeaders = new ResponseHeaders(new HeaderDictionary());
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
httpContext.Request.GetTypedHeaders().IfNoneMatch = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") });
Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
}
[Fact]
public void ConditionalRequestSatisfied_IfNoneMatch_ExplicitWithMatch_Passes()
{
var cachedHeaders = new ResponseHeaders(new HeaderDictionary())
{
ETag = new EntityTagHeaderValue("\"E1\"")
};
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
httpContext.Request.GetTypedHeaders().IfNoneMatch = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") });
Assert.True(context.ConditionalRequestSatisfied(cachedHeaders));
}
[Fact]
public void ConditionalRequestSatisfied_IfNoneMatch_ExplicitWithoutMatch_Fails()
{
var cachedHeaders = new ResponseHeaders(new HeaderDictionary())
{
ETag = new EntityTagHeaderValue("\"E2\"")
};
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
httpContext.Request.GetTypedHeaders().IfNoneMatch = new List<EntityTagHeaderValue>(new[] { new EntityTagHeaderValue("\"E1\"") });
Assert.False(context.ConditionalRequestSatisfied(cachedHeaders));
}
[Fact]
public void FinalizeCachingHeaders_DoNotUpdateShouldCacheResponse_IfResponseIsNotCacheable()
{
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext, cacheabilityValidator: new CacheabilityValidator());
var state = httpContext.GetResponseCachingState();
Assert.False(state.ShouldCacheResponse);
context.ShimResponseStream();
context.FinalizeCachingHeaders();
Assert.False(state.ShouldCacheResponse);
}
[Fact]
public void FinalizeCachingHeaders_UpdateShouldCacheResponse_IfResponseIsCacheable()
{
var httpContext = new DefaultHttpContext();
httpContext.Response.GetTypedHeaders().CacheControl = new CacheControlHeaderValue()
{
Public = true
};
var context = CreateTestContext(httpContext, cacheabilityValidator: new CacheabilityValidator());
var state = httpContext.GetResponseCachingState();
Assert.False(state.ShouldCacheResponse);
context.FinalizeCachingHeaders();
Assert.True(state.ShouldCacheResponse);
}
[Fact]
public void FinalizeCachingHeaders_DefaultResponseValidity_Is10Seconds()
{
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
context.FinalizeCachingHeaders();
Assert.Equal(TimeSpan.FromSeconds(10), httpContext.GetResponseCachingState().CachedResponseValidFor);
}
[Fact]
public void FinalizeCachingHeaders_ResponseValidity_UseExpiryIfAvailable()
{
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
var state = httpContext.GetResponseCachingState();
var utcNow = DateTimeOffset.MinValue;
state.ResponseTime = utcNow;
state.ResponseHeaders.Expires = utcNow + TimeSpan.FromSeconds(11);
context.FinalizeCachingHeaders();
Assert.Equal(TimeSpan.FromSeconds(11), state.CachedResponseValidFor);
}
[Fact]
public void FinalizeCachingHeaders_ResponseValidity_UseMaxAgeIfAvailable()
{
var httpContext = new DefaultHttpContext();
httpContext.Response.GetTypedHeaders().CacheControl = new CacheControlHeaderValue()
{
MaxAge = TimeSpan.FromSeconds(12)
};
var context = CreateTestContext(httpContext);
var state = httpContext.GetResponseCachingState();
state.ResponseTime = DateTimeOffset.UtcNow;
state.ResponseHeaders.Expires = state.ResponseTime + TimeSpan.FromSeconds(11);
context.FinalizeCachingHeaders();
Assert.Equal(TimeSpan.FromSeconds(12), state.CachedResponseValidFor);
}
[Fact]
public void FinalizeCachingHeaders_ResponseValidity_UseSharedMaxAgeIfAvailable()
{
var httpContext = new DefaultHttpContext();
httpContext.Response.GetTypedHeaders().CacheControl = new CacheControlHeaderValue()
{
MaxAge = TimeSpan.FromSeconds(12),
SharedMaxAge = TimeSpan.FromSeconds(13)
};
var context = CreateTestContext(httpContext);
var state = httpContext.GetResponseCachingState();
state.ResponseTime = DateTimeOffset.UtcNow;
state.ResponseHeaders.Expires = state.ResponseTime + TimeSpan.FromSeconds(11);
context.FinalizeCachingHeaders();
Assert.Equal(TimeSpan.FromSeconds(13), state.CachedResponseValidFor);
}
[Fact]
public void FinalizeCachingHeaders_UpdateCachedVaryRules_IfNotEquivalentToPrevious()
{
var httpContext = new DefaultHttpContext();
var cache = new TestResponseCache();
var context = CreateTestContext(httpContext, cache);
var state = httpContext.GetResponseCachingState();
httpContext.Response.Headers[HeaderNames.Vary] = new StringValues(new[] { "headerA", "HEADERB", "HEADERc" });
httpContext.AddResponseCachingFeature();
httpContext.GetResponseCachingFeature().VaryParams = new StringValues(new[] { "paramB", "PARAMAA" });
var cachedVaryRules = new CachedVaryRules()
{
VaryRules = new VaryRules()
{
Headers = new StringValues(new[] { "HeaderA", "HeaderB" }),
Params = new StringValues(new[] { "ParamA", "ParamB" })
}
};
state.CachedVaryRules = cachedVaryRules;
context.FinalizeCachingHeaders();
Assert.Equal(1, cache.SetCount);
Assert.NotSame(cachedVaryRules, state.CachedVaryRules);
}
[Fact]
public void FinalizeCachingHeaders_DoNotUpdateCachedVaryRules_IfEquivalentToPrevious()
{
var httpContext = new DefaultHttpContext();
var cache = new TestResponseCache();
var context = CreateTestContext(httpContext, cache);
var state = httpContext.GetResponseCachingState();
httpContext.Response.Headers[HeaderNames.Vary] = new StringValues(new[] { "headerA", "HEADERB" });
httpContext.AddResponseCachingFeature();
httpContext.GetResponseCachingFeature().VaryParams = new StringValues(new[] { "paramB", "PARAMA" });
var cachedVaryRules = new CachedVaryRules()
{
VaryKeyPrefix = FastGuid.NewGuid().IdString,
VaryRules = new VaryRules()
{
Headers = new StringValues(new[] { "HEADERA", "HEADERB" }),
Params = new StringValues(new[] { "PARAMA", "PARAMB" })
}
};
state.CachedVaryRules = cachedVaryRules;
context.FinalizeCachingHeaders();
Assert.Equal(0, cache.SetCount);
Assert.Same(cachedVaryRules, state.CachedVaryRules);
}
[Fact]
public void FinalizeCachingHeaders_DoNotAddDate_IfSpecified()
{
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
var state = httpContext.GetResponseCachingState();
var utcNow = DateTimeOffset.MinValue;
state.ResponseTime = utcNow;
Assert.Null(state.ResponseHeaders.Date);
context.FinalizeCachingHeaders();
Assert.Equal(utcNow, state.ResponseHeaders.Date);
}
[Fact]
public void FinalizeCachingHeaders_AddsDate_IfNoneSpecified()
{
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
var state = httpContext.GetResponseCachingState();
var utcNow = DateTimeOffset.MinValue;
state.ResponseHeaders.Date = utcNow;
state.ResponseTime = utcNow + TimeSpan.FromSeconds(10);
Assert.Equal(utcNow, state.ResponseHeaders.Date);
context.FinalizeCachingHeaders();
Assert.Equal(utcNow, state.ResponseHeaders.Date);
}
[Fact]
public void FinalizeCachingHeaders_StoresCachedResponse_InState()
{
var httpContext = new DefaultHttpContext();
var context = CreateTestContext(httpContext);
var state = httpContext.GetResponseCachingState();
Assert.Null(state.CachedResponse);
context.FinalizeCachingHeaders();
Assert.NotNull(state.CachedResponse);
}
[Fact]
public async Task FinalizeCachingBody_StoreResponseBodySeparately_IfLargerThanLimit()
{
var httpContext = new DefaultHttpContext();
var cache = new TestResponseCache();
var context = CreateTestContext(httpContext, cache);
context.ShimResponseStream();
await httpContext.Response.WriteAsync(new string('0', 70 * 1024));
var state = httpContext.GetResponseCachingState();
state.ShouldCacheResponse = true;
state.CachedResponse = new CachedResponse()
{
BodyKeyPrefix = FastGuid.NewGuid().IdString
};
state.StorageBaseKey = "BaseKey";
state.CachedResponseValidFor = TimeSpan.FromSeconds(10);
context.FinalizeCachingBody();
Assert.Equal(2, cache.SetCount);
}
[Fact]
public async Task FinalizeCachingBody_StoreResponseBodyInCachedResponse_IfSmallerThanLimit()
{
var httpContext = new DefaultHttpContext();
var cache = new TestResponseCache();
var context = CreateTestContext(httpContext, cache);
context.ShimResponseStream();
await httpContext.Response.WriteAsync(new string('0', 70 * 1024 - 1));
var state = httpContext.GetResponseCachingState();
state.ShouldCacheResponse = true;
state.CachedResponse = new CachedResponse()
{
BodyKeyPrefix = FastGuid.NewGuid().IdString
};
state.StorageBaseKey = "BaseKey";
state.CachedResponseValidFor = TimeSpan.FromSeconds(10);
context.FinalizeCachingBody();
Assert.Equal(1, cache.SetCount);
}
[Fact]
public async Task FinalizeCachingBody_StoreResponseBodySeparately_LimitIsConfigurable()
{
var httpContext = new DefaultHttpContext();
var cache = new TestResponseCache();
var context = CreateTestContext(httpContext, cache, new ResponseCachingOptions()
{
MinimumSplitBodySize = 2048
});
context.ShimResponseStream();
await httpContext.Response.WriteAsync(new string('0', 1024));
var state = httpContext.GetResponseCachingState();
state.ShouldCacheResponse = true;
state.CachedResponse = new CachedResponse()
{
BodyKeyPrefix = FastGuid.NewGuid().IdString
};
state.StorageBaseKey = "BaseKey";
state.CachedResponseValidFor = TimeSpan.FromSeconds(10);
context.FinalizeCachingBody();
Assert.Equal(1, cache.SetCount);
}
[Fact]
public async Task FinalizeCachingBody_Cache_IfContentLengthMatches()
{
var httpContext = new DefaultHttpContext();
var cache = new TestResponseCache();
var context = CreateTestContext(httpContext, cache);
context.ShimResponseStream();
httpContext.Response.ContentLength = 10;
await httpContext.Response.WriteAsync(new string('0', 10));
var state = httpContext.GetResponseCachingState();
state.ShouldCacheResponse = true;
state.CachedResponse = new CachedResponse()
{
BodyKeyPrefix = FastGuid.NewGuid().IdString
};
state.StorageBaseKey = "BaseKey";
state.CachedResponseValidFor = TimeSpan.FromSeconds(10);
context.FinalizeCachingBody();
Assert.Equal(1, cache.SetCount);
}
[Fact]
public async Task FinalizeCachingBody_DoNotCache_IfContentLengthMismatches()
{
var httpContext = new DefaultHttpContext();
var cache = new TestResponseCache();
var context = CreateTestContext(httpContext, cache);
context.ShimResponseStream();
httpContext.Response.ContentLength = 9;
await httpContext.Response.WriteAsync(new string('0', 10));
var state = httpContext.GetResponseCachingState();
state.ShouldCacheResponse = true;
state.CachedResponse = new CachedResponse()
{
BodyKeyPrefix = FastGuid.NewGuid().IdString
};
state.StorageBaseKey = "BaseKey";
state.CachedResponseValidFor = TimeSpan.FromSeconds(10);
context.FinalizeCachingBody();
Assert.Equal(0, cache.SetCount);
}
[Fact]
public async Task FinalizeCachingBody_Cache_IfContentLengthAbsent()
{
var httpContext = new DefaultHttpContext();
var cache = new TestResponseCache();
var context = CreateTestContext(httpContext, cache);
context.ShimResponseStream();
await httpContext.Response.WriteAsync(new string('0', 10));
var state = httpContext.GetResponseCachingState();
state.ShouldCacheResponse = true;
state.CachedResponse = new CachedResponse()
{
BodyKeyPrefix = FastGuid.NewGuid().IdString
};
state.StorageBaseKey = "BaseKey";
state.CachedResponseValidFor = TimeSpan.FromSeconds(10);
context.FinalizeCachingBody();
Assert.Equal(1, cache.SetCount);
}
[Fact]
public void NormalizeStringValues_NormalizesCasingToUpper()
{
var uppercaseStrings = new StringValues(new[] { "STRINGA", "STRINGB" });
var lowercaseStrings = new StringValues(new[] { "stringA", "stringB" });
var normalizedStrings = ResponseCachingContext.GetNormalizedStringValues(lowercaseStrings);
Assert.Equal(uppercaseStrings, normalizedStrings);
}
[Fact]
public void NormalizeStringValues_NormalizesOrder()
{
var orderedStrings = new StringValues(new[] { "STRINGA", "STRINGB" });
var reverseOrderStrings = new StringValues(new[] { "STRINGB", "STRINGA" });
var normalizedStrings = ResponseCachingContext.GetNormalizedStringValues(reverseOrderStrings);
Assert.Equal(orderedStrings, normalizedStrings);
}
private static ResponseCachingContext CreateTestContext(
HttpContext httpContext,
IResponseCache responseCache = null,
ResponseCachingOptions options = null,
IKeyProvider keyProvider = null,
ICacheabilityValidator cacheabilityValidator = null)
{
if (responseCache == null)
{
responseCache = new TestResponseCache();
}
if (options == null)
{
options = new ResponseCachingOptions();
}
if (keyProvider == null)
{
keyProvider = new KeyProvider(new DefaultObjectPoolProvider(), Options.Create(options));
}
if (cacheabilityValidator == null)
{
cacheabilityValidator = new TestCacheabilityValidator();
}
httpContext.AddResponseCachingState();
return new ResponseCachingContext(
httpContext,
responseCache,
options,
cacheabilityValidator,
keyProvider);
}
private class TestCacheabilityValidator : ICacheabilityValidator
{
public bool CachedEntryIsFresh(HttpContext httpContext, ResponseHeaders cachedResponseHeaders) => true;
public bool RequestIsCacheable(HttpContext httpContext) => true;
public bool ResponseIsCacheable(HttpContext httpContext) => true;
}
private class TestKeyProvider : IKeyProvider
{
private readonly StringValues _baseKey;
private readonly StringValues _varyKey;
public TestKeyProvider(StringValues? lookupBaseKey = null, StringValues? lookupVaryKey = null)
{
if (lookupBaseKey.HasValue)
{
_baseKey = lookupBaseKey.Value;
}
if (lookupVaryKey.HasValue)
{
_varyKey = lookupVaryKey.Value;
}
}
public IEnumerable<string> CreateLookupBaseKey(HttpContext httpContext) => _baseKey;
public IEnumerable<string> CreateLookupVaryKey(HttpContext httpContext, VaryRules varyRules)
{
foreach (var baseKey in _baseKey)
{
foreach (var varyKey in _varyKey)
{
yield return baseKey + varyKey;
}
}
}
public string CreateBodyKey(HttpContext httpContext)
{
throw new NotImplementedException();
}
public string CreateStorageBaseKey(HttpContext httpContext)
{
throw new NotImplementedException();
}
public string CreateStorageVaryKey(HttpContext httpContext, VaryRules varyRules)
{
throw new NotImplementedException();
}
}
private class TestResponseCache : IResponseCache
{
private readonly IDictionary<string, object> _storage = new Dictionary<string, object>();
public int GetCount { get; private set; }
public int SetCount { get; private set; }
public object Get(string key)
{
GetCount++;
try
{
return _storage[key];
}
catch
{
return null;
}
}
public void Remove(string key)
{
}
public void Set(string key, object entry, TimeSpan validFor)
{
SetCount++;
_storage[key] = entry;
}
}
private class TestHttpSendFileFeature : IHttpSendFileFeature
{
public Task SendFileAsync(string path, long offset, long? count, CancellationToken cancellation)
{
return TaskCache.CompletedTask;
}
}
}
}