public void TryParseList_WithSomeInvalidValues_ExcludesInvalidValues()
{
var inputs = new[]
{
"",
"\"tag\", tag, \"tag\"",
"tag, \"tag\"",
"",
" \"tag ",
"\r\n tag\"\r\n ",
"\"tag会\"",
"\"tag\", \"tag\"",
"W/\"tag\"",
};
Assert.True(EntityTagHeaderValue.TryParseList(inputs, out var results));
var expectedResults = new[]
{
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag会\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\"", true),
}.ToList();
Assert.Equal(expectedResults, results);
}
public void TryParseList_SetOfValidValueStrings_ParsedCorrectly()
{
var inputs = new[]
{
"",
"\"tag\"",
"",
" \"tag\" ",
"\r\n \"tag\"\r\n ",
"\"tag会\"",
"\"tag\",\"tag\"",
"\"tag\", \"tag\"",
"W/\"tag\"",
};
Assert.True(EntityTagHeaderValue.TryParseList(inputs, out var results));
var expectedResults = new[]
{
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag会\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\""),
new EntityTagHeaderValue("\"tag\"", true),
}.ToList();
Assert.Equal(expectedResults, results);
}
internal static bool ContentIsNotModified(ResponseCachingContext context)
{
var cachedResponseHeaders = context.CachedResponseHeaders;
var ifNoneMatchHeader = context.HttpContext.Request.Headers[HeaderNames.IfNoneMatch];
if (!StringValues.IsNullOrEmpty(ifNoneMatchHeader))
{
if (ifNoneMatchHeader.Count == 1 && StringSegment.Equals(ifNoneMatchHeader[0], EntityTagHeaderValue.Any.Tag, StringComparison.OrdinalIgnoreCase))
{
context.Logger.LogNotModifiedIfNoneMatchStar();
return(true);
}
EntityTagHeaderValue eTag;
IList <EntityTagHeaderValue> ifNoneMatchEtags;
if (!StringValues.IsNullOrEmpty(cachedResponseHeaders[HeaderNames.ETag]) &&
EntityTagHeaderValue.TryParse(cachedResponseHeaders[HeaderNames.ETag].ToString(), out eTag) &&
EntityTagHeaderValue.TryParseList(ifNoneMatchHeader, out ifNoneMatchEtags))
{
for (var i = 0; i < ifNoneMatchEtags.Count; i++)
{
var requestETag = ifNoneMatchEtags[i];
if (eTag.Compare(requestETag, useStrongComparison: false))
{
context.Logger.LogNotModifiedIfNoneMatchMatched(requestETag);
return(true);
}
}
}
}
else
{
var ifModifiedSince = context.HttpContext.Request.Headers[HeaderNames.IfModifiedSince];
if (!StringValues.IsNullOrEmpty(ifModifiedSince))
{
DateTimeOffset modified;
if (!HeaderUtilities.TryParseDate(cachedResponseHeaders[HeaderNames.LastModified].ToString(), out modified) &&
!HeaderUtilities.TryParseDate(cachedResponseHeaders[HeaderNames.Date].ToString(), out modified))
{
return(false);
}
DateTimeOffset modifiedSince;
if (HeaderUtilities.TryParseDate(ifModifiedSince.ToString(), out modifiedSince) &&
modified <= modifiedSince)
{
context.Logger.LogNotModifiedIfModifiedSinceSatisfied(modified, modifiedSince);
return(true);
}
}
}
return(false);
}
private static bool EtagEquals(HttpRequest request, EntityTagHeaderValue currentEtag)
{
// CORE TODO Double check this... before I found the GetTypedHeaders() extension method, I didn't think there was a typed implementation of the IfNoneMatch header
// anymore, so I reimplemented based on the response caching middleware's implementation, leaving out the * match. See
// https://github.com/aspnet/ResponseCaching/blob/52e8ffefb9b22c7c591aec15845baf07ed99356c/src/Microsoft.AspNetCore.ResponseCaching/ResponseCachingMiddleware.cs#L454-L478
var ifNoneMatchHeader = request.Headers["If-None-Match"];
if (StringValues.IsNullOrEmpty(ifNoneMatchHeader))
{
return(false);
}
return(EntityTagHeaderValue.TryParseList(ifNoneMatchHeader, out IList <Microsoft.Net.Http.Headers.EntityTagHeaderValue> ifNoneMatchEtags) &&
ifNoneMatchEtags.Any(t => currentEtag.Compare(t, useStrongComparison: false)));
}
private static bool RequestContainsMatchingETag(IHeaderDictionary requestHeaders, EntityTagHeaderValue responseETag)
{
if (requestHeaders.Keys.Contains(HeaderNames.IfNoneMatch) &&
EntityTagHeaderValue.TryParseList(requestHeaders[HeaderNames.IfNoneMatch], out IList <EntityTagHeaderValue> requestETags))
{
foreach (EntityTagHeaderValue requestETag in requestETags)
{
if (responseETag.Equals(requestETag))
{
return(true);
}
}
}
return(false);
}
public static async Task <ActionResult> GenerateActionResult(ControllerBase controller, ICacheableDataProvider provider, TimeSpan?maxAge = null)
{
const string CacheControlHeaderKey = "Cache-Control";
const string IfNonMatchHeaderKey = "If-None-Match";
const string IfModifiedSinceHeaderKey = "If-Modified-Since";
const string ETagHeaderKey = "ETag";
const string LastModifiedHeaderKey = "Last-Modified";
string GenerateCacheControlHeaderValue()
{
var cacheControlHeader = new CacheControlHeaderValue()
{
NoCache = true,
NoStore = false,
MaxAge = maxAge ?? TimeSpan.FromDays(14),
Private = true,
MustRevalidate = true
};
return(cacheControlHeader.ToString());
}
var digest = await provider.GetDigest();
var eTagValue = $"\"{digest.ETag}\"";
var eTag = new EntityTagHeaderValue(eTagValue);
ActionResult Generate304Result()
{
controller.Response.Headers.Add(ETagHeaderKey, eTagValue);
controller.Response.Headers.Add(LastModifiedHeaderKey, digest.LastModified.ToString("R"));
controller.Response.Headers.Add(CacheControlHeaderKey, GenerateCacheControlHeaderValue());
return(controller.StatusCode(StatusCodes.Status304NotModified, null));
}
if (controller.Request.Headers.TryGetValue(IfNonMatchHeaderKey, out var ifNonMatchHeaderValue))
{
if (!EntityTagHeaderValue.TryParseList(ifNonMatchHeaderValue, out var eTagList))
{
return(controller.BadRequest(new CommonResponse(ErrorCodes.Common.Header.IfNonMatch_BadFormat, "Header If-None-Match is of bad format.")));
}
if (eTagList.FirstOrDefault(e => e.Equals(eTag)) != null)
{
return(Generate304Result());
}
}
else if (controller.Request.Headers.TryGetValue(IfModifiedSinceHeaderKey, out var ifModifiedSinceHeaderValue))
{
if (!DateTime.TryParse(ifModifiedSinceHeaderValue, out var headerValue))
{
return(controller.BadRequest(new CommonResponse(ErrorCodes.Common.Header.IfModifiedSince_BadFormat, "Header If-Modified-Since is of bad format.")));
}
if (headerValue > digest.LastModified)
{
return(Generate304Result());
}
}
var data = await provider.GetData();
controller.Response.Headers.Add(CacheControlHeaderKey, GenerateCacheControlHeaderValue());
return(controller.File(data.Data, data.ContentType, digest.LastModified, eTag));
}
public void TryParseList_NullOrEmptyArray_ReturnsFalse()
{
Assert.False(EntityTagHeaderValue.TryParseList(null, out var results));
Assert.False(EntityTagHeaderValue.TryParseList(new string[0], out results));
Assert.False(EntityTagHeaderValue.TryParseList(new string[] { "" }, out results));
}