private void CheckValidTryParse(string input, CacheControlHeaderValue expectedResult)
{
CacheControlHeaderValue result = null;
Assert.True(CacheControlHeaderValue.TryParse(input, out result));
Assert.Equal(expectedResult, result);
}
private void CheckInvalidTryParse(string input, int startIndex)
{
CacheControlHeaderValue result = null;
Assert.False(CacheControlHeaderValue.TryParse(input, out result));
Assert.Null(result);
}
private void LogCacheHeaderOverrideWarning(HttpResponse response)
{
var logWarning = false;
CacheControlHeaderValue cacheControlHeaderValue;
if (CacheControlHeaderValue.TryParse(response.Headers[HeaderNames.CacheControl].ToString(), out cacheControlHeaderValue))
{
if (!cacheControlHeaderValue.NoCache)
{
logWarning = true;
}
}
var pragmaHeader = response.Headers[HeaderNames.Pragma];
if (!logWarning &&
!string.IsNullOrEmpty(pragmaHeader) &&
string.Compare(pragmaHeader, "no-cache", ignoreCase: true) != 0)
{
logWarning = true;
}
if (logWarning)
{
_logger.ResponseCacheHeadersOverridenToNoCache();
}
}
public void TryParse()
{
CacheControlHeaderValue res;
Assert.IsTrue(CacheControlHeaderValue.TryParse("*", out res), "#1");
Assert.AreEqual(1, res.Extensions.Count, "#2");
}
private void AddToCache(string resource, HttpResponseMessage response)
{
var cacheHeader = response.Headers.FirstOrDefault(h => h.Key == "cache-control");
if (!string.IsNullOrEmpty(cacheHeader.Key) &&
CacheControlHeaderValue.TryParse(cacheHeader.Value.ToString(), out var cacheControl) &&
cacheControl?.MaxAge.HasValue is true)
{
this.cache.Add(resource, response, cacheControl.MaxAge !.Value);
}
}
public static void initialHttpRequestMessage(OssHttpRequestMessage hReqMes, ObjectMetadata metadata)
{
if (metadata.CacheControl != null)
{
CacheControlHeaderValue temp;
if (CacheControlHeaderValue.TryParse(metadata.CacheControl, out temp) == true)
{
hReqMes.Headers.CacheControl = temp;
}
}
if (metadata.ContentDisposition != null)
{
ContentDispositionHeaderValue temp;
if (ContentDispositionHeaderValue.TryParse(metadata.CacheControl, out temp) == true)
{
hReqMes.Content.Headers.ContentDisposition = temp;
}
}
if (metadata.ContentLength != 0)
{
hReqMes.Content.Headers.ContentLength = metadata.ContentLength;
}
if (metadata.ContentType != null)
{
MediaTypeHeaderValue temp;
if (MediaTypeHeaderValue.TryParse(metadata.CacheControl, out temp) == true)
{
hReqMes.Content.Headers.ContentType = temp;
}
else
{
hReqMes.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
}
}
else
{
hReqMes.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
}
//if (metadata.ExpirationTime != null)
//{
// hReqMes.Content.Headers.Expires = metadata.ExpirationTime;
//}
foreach (KeyValuePair <string, string> entry in metadata.UserMetadata)
{
hReqMes.Headers.Pragma.Add(new NameValueHeaderValue("x-oss-meta-" + entry.Key, entry.Value));
}
}
private static TimeSpan?GetCacheTtl(RequestContext requestContext)
{
var response = requestContext.Response;
// Only consider kernel-mode caching if the Cache-Control response header is present.
var cacheControlHeader = response.Headers[HeaderNames.CacheControl];
if (string.IsNullOrEmpty(cacheControlHeader))
{
return(null);
}
// Before we check the header value, check for the existence of other headers which would
// make us *not* want to cache the response.
if (response.Headers.ContainsKey(HeaderNames.SetCookie) ||
response.Headers.ContainsKey(HeaderNames.Vary) ||
response.Headers.ContainsKey(HeaderNames.Pragma))
{
return(null);
}
// We require 'public' and 's-max-age' or 'max-age' or the Expires header.
CacheControlHeaderValue cacheControl;
if (CacheControlHeaderValue.TryParse(cacheControlHeader, out cacheControl) && cacheControl.Public)
{
if (cacheControl.SharedMaxAge.HasValue)
{
return(cacheControl.SharedMaxAge);
}
else if (cacheControl.MaxAge.HasValue)
{
return(cacheControl.MaxAge);
}
DateTimeOffset expirationDate;
if (HeaderUtilities.TryParseDate(response.Headers[HeaderNames.Expires], out expirationDate))
{
var expiresOffset = expirationDate - DateTimeOffset.UtcNow;
if (expiresOffset > TimeSpan.Zero)
{
return(expiresOffset);
}
}
}
return(null);
}
public static CacheControlHeaderValue GetWatCacheControlHeader(this HttpRequestMessage request)
{
IEnumerable <string> headerValues;
if (request.Headers.TryGetValues(CacheControlHeaderName, out headerValues))
{
foreach (var header in headerValues)
{
CacheControlHeaderValue cacheControlHeader;
if (CacheControlHeaderValue.TryParse(header, out cacheControlHeader))
{
return(cacheControlHeader);
}
}
}
return(new CacheControlHeaderValue());
}
/// <inheritdoc />
public async Task <ImageMetadata> GetMetaDataAsync()
{
GetObjectMetadataResponse metadata = await this.amazonS3.GetObjectMetadataAsync(this.bucketName, this.imagePath);
// Try to parse the max age from the source. If it's not zero then we pass it along
// to set the cache control headers for the response.
TimeSpan maxAge = TimeSpan.MinValue;
if (CacheControlHeaderValue.TryParse(metadata.Headers.CacheControl, out CacheControlHeaderValue cacheControl))
{
// Weirdly passing null to TryParse returns true.
if (cacheControl?.MaxAge.HasValue == true)
{
maxAge = cacheControl.MaxAge.Value;
}
}
return(new ImageMetadata(metadata.LastModified, maxAge, metadata.ContentLength));
}
/// <summary>
/// Sets the 'Cache-Control' header to 'no-cache, no-store' and 'Pragma' header to 'no-cache' overriding any user set value.
/// </summary>
/// <param name="httpContext">The <see cref="HttpContext"/>.</param>
protected virtual void SetDoNotCacheHeaders(HttpContext httpContext)
{
var logWarning = false;
var responseHeaders = httpContext.Response.Headers;
if (responseHeaders.TryGetValue(HeaderNames.CacheControl, out var cacheControlHeader) &&
CacheControlHeaderValue.TryParse(cacheControlHeader.ToString(), out var cacheControlHeaderValue))
{
// If the Cache-Control is already set, override it only if required
if (!cacheControlHeaderValue.NoCache || !cacheControlHeaderValue.NoStore)
{
logWarning = true;
responseHeaders.CacheControl = "no-cache, no-store";
}
}
else
{
responseHeaders.CacheControl = "no-cache, no-store";
}
if (responseHeaders.TryGetValue(HeaderNames.Pragma, out var pragmaHeader) && pragmaHeader.Count > 0)
{
// If the Pragma is already set, override it only if required
if (!string.Equals(pragmaHeader[0], "no-cache", StringComparison.OrdinalIgnoreCase))
{
logWarning = true;
httpContext.Response.Headers.Pragma = "no-cache";
}
}
else
{
httpContext.Response.Headers.Pragma = "no-cache";
}
// Since antiforgery token generation is not very obvious to the end users (ex: MVC's form tag generates them
// by default), log a warning to let users know of the change in behavior to any cache headers they might
// have set explicitly.
if (logWarning)
{
_logger.ResponseCacheHeadersOverridenToNoCache();
}
}
private void CheckInvalidTryParse(string?input)
{
Assert.False(CacheControlHeaderValue.TryParse(input, out var result));
Assert.Null(result);
}
