/// <summary>
/// Creates an instance of <see cref="CacheTagKey"/> for a specific <see cref="CacheTagHelper"/>.
/// </summary>
/// <param name="tagHelper">The <see cref="CacheTagHelper"/>.</param>
/// <param name="context">The <see cref="TagHelperContext"/>.</param>
/// <returns>A new <see cref="CacheTagKey"/>.</returns>
public CacheTagKey(CacheTagHelper tagHelper, TagHelperContext context)
: this(tagHelper)
{
Key = context.UniqueId;
_prefix = nameof(CacheTagHelper);
}
public async Task ProcessAsync_ExceptionInProcessing_DoesntBlockConcurrentRequests()
{
// Arrange
var id = "unique-id";
var childContent = "some-content";
var event1 = new TaskCompletionSource <int>(TaskCreationOptions.RunContinuationsAsynchronously);
var event2 = new TaskCompletionSource <int>(TaskCreationOptions.RunContinuationsAsynchronously);
var event3 = new TaskCompletionSource <int>(TaskCreationOptions.RunContinuationsAsynchronously);
var calls = 0;
var cache = new MemoryCache(new MemoryCacheOptions());
var tagHelperContext1 = GetTagHelperContext(id + 1);
var tagHelperContext2 = GetTagHelperContext(id + 2);
var tagHelperOutput1 = new TagHelperOutput(
"cache",
new TagHelperAttributeList(),
getChildContentAsync: (useCachedResult, encoder) =>
{
calls++;
event2.SetResult(0);
throw new Exception();
});
var tagHelperOutput2 = new TagHelperOutput(
"cache",
new TagHelperAttributeList(),
getChildContentAsync: async(useCachedResult, encoder) =>
{
calls++;
await event3.Task.TimeoutAfter(TimeSpan.FromSeconds(5));
var tagHelperContent = new DefaultTagHelperContent();
tagHelperContent.SetHtmlContent(childContent);
return(tagHelperContent);
});
var cacheTagHelper1 = new CacheTagHelper(new CacheTagHelperMemoryCacheFactory(cache), new HtmlTestEncoder())
{
ViewContext = GetViewContext(),
Enabled = true
};
var cacheTagHelper2 = new CacheTagHelper(new CacheTagHelperMemoryCacheFactory(cache), new HtmlTestEncoder())
{
ViewContext = GetViewContext(),
Enabled = true
};
// Act
var task1 = Task.Run(async() =>
{
await event1.Task.TimeoutAfter(TimeSpan.FromSeconds(5));
await Assert.ThrowsAsync <Exception>(() => cacheTagHelper1.ProcessAsync(tagHelperContext1, tagHelperOutput1));
event3.SetResult(0);
});
var task2 = Task.Run(async() =>
{
await event2.Task.TimeoutAfter(TimeSpan.FromSeconds(5));
await cacheTagHelper2.ProcessAsync(tagHelperContext2, tagHelperOutput2);
});
event1.SetResult(0);
await Task.WhenAll(task1, task2);
// Assert
Assert.Empty(tagHelperOutput1.PreContent.GetContent());
Assert.Empty(tagHelperOutput1.PostContent.GetContent());
Assert.False(tagHelperOutput1.IsContentModified);
Assert.Empty(tagHelperOutput1.Content.GetContent());
Assert.Empty(tagHelperOutput2.PreContent.GetContent());
Assert.Empty(tagHelperOutput2.PostContent.GetContent());
Assert.True(tagHelperOutput2.IsContentModified);
Assert.Equal(childContent, tagHelperOutput2.Content.GetContent());
Assert.Equal(2, calls);
}
public async Task ProcessAsync_ExceptionInProcessing_DoNotThrowInSubsequentRequests()
{
// Arrange
var id = "unique-id";
var childContent = "some-content";
var cache = new MemoryCache(new MemoryCacheOptions());
var counter = 0;
Task <TagHelperContent> GetChildContentAsync(bool useCachedResult, HtmlEncoder encoder)
{
counter++;
if (counter < 3)
{
// throw on first two calls
throw new Exception();
}
else
{
// produce content on third call
var tagHelperContent = new DefaultTagHelperContent();
tagHelperContent.SetHtmlContent(childContent);
return(Task.FromResult <TagHelperContent>(tagHelperContent));
}
}
var tagHelperContext1 = GetTagHelperContext(id);
var tagHelperContext2 = GetTagHelperContext(id);
var tagHelperContext3 = GetTagHelperContext(id);
var tagHelperContext4 = GetTagHelperContext(id);
var tagHelperOutput1 = new TagHelperOutput("cache", new TagHelperAttributeList(), GetChildContentAsync);
var tagHelperOutput2 = new TagHelperOutput("cache", new TagHelperAttributeList(), GetChildContentAsync);
var tagHelperOutput3 = new TagHelperOutput("cache", new TagHelperAttributeList(), GetChildContentAsync);
var tagHelperOutput4 = new TagHelperOutput("cache", new TagHelperAttributeList(), GetChildContentAsync);
var cacheTagHelper = new CacheTagHelper(new CacheTagHelperMemoryCacheFactory(cache), new HtmlTestEncoder())
{
ViewContext = GetViewContext(),
Enabled = true,
ExpiresAfter = TimeSpan.FromHours(1.0)
};
// Act - 1
await Assert.ThrowsAsync <Exception>(() => cacheTagHelper.ProcessAsync(tagHelperContext1, tagHelperOutput1));
// Assert - 1
Assert.Equal(1, counter);
Assert.Empty(tagHelperOutput1.PreContent.GetContent());
Assert.Empty(tagHelperOutput1.PostContent.GetContent());
Assert.False(tagHelperOutput1.IsContentModified);
Assert.Empty(tagHelperOutput1.Content.GetContent());
// Act - 2
await Assert.ThrowsAsync <Exception>(() => cacheTagHelper.ProcessAsync(tagHelperContext2, tagHelperOutput2));
// Assert - 2
Assert.Equal(2, counter);
Assert.Empty(tagHelperOutput2.PreContent.GetContent());
Assert.Empty(tagHelperOutput2.PostContent.GetContent());
Assert.False(tagHelperOutput2.IsContentModified);
Assert.Empty(tagHelperOutput2.Content.GetContent());
// Act - 3
await cacheTagHelper.ProcessAsync(tagHelperContext3, tagHelperOutput3);
// Assert - 3
Assert.Equal(3, counter);
Assert.Empty(tagHelperOutput3.PreContent.GetContent());
Assert.Empty(tagHelperOutput3.PostContent.GetContent());
Assert.True(tagHelperOutput3.IsContentModified);
Assert.Equal(childContent, tagHelperOutput3.Content.GetContent());
// Act - 4
await cacheTagHelper.ProcessAsync(tagHelperContext4, tagHelperOutput4);
// Assert - 4
Assert.Equal(3, counter);
Assert.Empty(tagHelperOutput4.PreContent.GetContent());
Assert.Empty(tagHelperOutput4.PostContent.GetContent());
Assert.True(tagHelperOutput4.IsContentModified);
Assert.Equal(childContent, tagHelperOutput4.Content.GetContent());
}
public async Task ProcessAsync_FlowsEntryLinkThatAllowsAddingTriggersToAddedEntry()
{
// Arrange
var id = "some-id";
var expectedContent = new DefaultTagHelperContent();
expectedContent.SetContent("some-content");
var tokenSource = new CancellationTokenSource();
var cache = new MemoryCache(new MemoryCacheOptions()
{
TrackLinkedCacheEntries = true
});
var cacheEntryOptions = new MemoryCacheEntryOptions()
.AddExpirationToken(new CancellationChangeToken(tokenSource.Token));
var tagHelperContext = new TagHelperContext(
tagName: "cache",
allAttributes: new TagHelperAttributeList(),
items: new Dictionary <object, object>(),
uniqueId: id);
var tagHelperOutput = new TagHelperOutput(
"cache",
new TagHelperAttributeList {
{ "attr", "value" }
},
getChildContentAsync: (useCachedResult, encoder) =>
{
if (!cache.TryGetValue("key1", out TagHelperContent tagHelperContent))
{
tagHelperContent = expectedContent;
cache.Set("key1", tagHelperContent, cacheEntryOptions);
}
return(Task.FromResult(tagHelperContent));
});
tagHelperOutput.PreContent.SetContent("<cache>");
tagHelperOutput.PostContent.SetContent("</cache>");
var cacheTagHelper = new CacheTagHelper(new CacheTagHelperMemoryCacheFactory(cache), new HtmlTestEncoder())
{
ViewContext = GetViewContext(),
};
var cacheTagKey = new CacheTagKey(cacheTagHelper, tagHelperContext);
var key = cacheTagKey.GenerateKey();
// Act - 1
await cacheTagHelper.ProcessAsync(tagHelperContext, tagHelperOutput);
var result = cache.TryGetValue(cacheTagKey, out Task <IHtmlContent> cachedValue);
// Assert - 1
Assert.Equal("HtmlEncode[[some-content]]", tagHelperOutput.Content.GetContent());
Assert.True(result);
// Act - 2
tokenSource.Cancel();
result = cache.TryGetValue(cacheTagKey, out cachedValue);
// Assert - 2
Assert.False(result);
Assert.Null(cachedValue);
}
