public void BasicWrites()
{
using (var writer = new ZStringWriter())
{
writer.Write("text1".AsSpan());
writer.Write("text2");
writer.Write('c');
writer.Write(true);
writer.Write(123);
writer.Write(456f);
writer.Write(789d);
writer.Write("end".AsMemory());
writer.WriteLine();
var expected = "text1text2cTrue123456789end" + Environment.NewLine;
Assert.Equal(expected, writer.ToString());
}
}
public async Task <IHtmlContent> ProcessContentAsync(TagHelperOutput output, CacheContext cacheContext)
{
IHtmlContent content = null;
while (content == null)
{
Task <IHtmlContent> result;
// Is there any request already processing the value?
if (!_dynamicCacheTagHelperService.Workers.TryGetValue(CacheId, out result))
{
// There is a small race condition here between TryGetValue and TryAdd that might cause the
// content to be computed more than once. We don't care about this race as the probability of
// happening is very small and the impact is not critical.
var tcs = new TaskCompletionSource <IHtmlContent>();
_dynamicCacheTagHelperService.Workers.TryAdd(CacheId, tcs.Task);
try
{
var value = await _dynamicCacheService.GetCachedValueAsync(cacheContext);
if (value == null)
{
// The value is not cached, we need to render the tag helper output
var processedContent = await output.GetChildContentAsync();
using var writer = new ZStringWriter();
// Write the start of a cache debug block.
if (_cacheOptions.DebugMode)
{
// No need to optimize this code as it will be used for debugging purpose.
writer.WriteLine();
writer.WriteLine($"<!-- CACHE BLOCK: {cacheContext.CacheId} ({Guid.NewGuid()})");
writer.WriteLine($" VARY BY: {String.Join(", ", cacheContext.Contexts)}");
writer.WriteLine($" DEPENDENCIES: {String.Join(", ", cacheContext.Tags)}");
writer.WriteLine($" EXPIRES ON: {cacheContext.ExpiresOn}");
writer.WriteLine($" EXPIRES AFTER: {cacheContext.ExpiresAfter}");
writer.WriteLine($" EXPIRES SLIDING: {cacheContext.ExpiresSliding}");
writer.WriteLine("-->");
}
// Always write the content regardless of debug mode.
processedContent.WriteTo(writer, HtmlEncoder);
// Write the end of a cache debug block.
if (_cacheOptions.DebugMode)
{
writer.WriteLine();
writer.WriteLine($"<!-- END CACHE BLOCK: {cacheContext.CacheId} -->");
}
await writer.FlushAsync();
var html = writer.ToString();
var formattingContext = new DistributedCacheTagHelperFormattingContext
{
Html = new HtmlString(html)
};
await _dynamicCacheService.SetCachedValueAsync(cacheContext, html);
content = formattingContext.Html;
}
else
{
content = new HtmlString(value);
}
}
catch
{
content = null;
throw;
}
finally
{
// Remove the worker task before setting the result.
// If the result is null, other threads would potentially
// acquire it otherwise.
_dynamicCacheTagHelperService.Workers.TryRemove(CacheId, out result);
// Notify all other awaiters to render the content
tcs.TrySetResult(content);
}
}
else
{
content = await result;
}
}
return(content);
}