private void GenerateVaryHeadersOnResponse(HttpContext httpContext, ValidationModelOptions validationModelOptions)
{
// cfr: https://tools.ietf.org/html/rfc7231#section-7.1.4
// Generate Vary header for response
// The "Vary" header field in a response describes what parts of a
// request message, aside from the method, Host header field, and
// request target, might influence the origin server's process for
// selecting and representing this response. The value consists of
// either a single asterisk ("*") or a list of header field names
// (case-insensitive).
_logger.LogInformation("Generating Vary header.");
var headers = httpContext.Response.Headers;
headers.Remove(HeaderNames.Vary);
var varyHeaderValue = validationModelOptions.VaryByAll
? "*"
: string.Join(", ", validationModelOptions.Vary);
headers[HeaderNames.Vary] = varyHeaderValue;
_logger.LogInformation($"Vary header generated: {varyHeaderValue}.");
}
public HttpCacheHeadersMiddleware(
RequestDelegate next,
IValidationValueStore store,
ILoggerFactory loggerFactory,
IOptions <ExpirationModelOptions> expirationModelOptions,
IOptions <ValidationModelOptions> validationModelOptions)
{
if (loggerFactory == null)
{
throw new ArgumentNullException(nameof(loggerFactory));
}
if (validationModelOptions == null)
{
throw new ArgumentNullException(nameof(validationModelOptions));
}
if (expirationModelOptions == null)
{
throw new ArgumentNullException(nameof(expirationModelOptions));
}
_next = next ?? throw new ArgumentNullException(nameof(next));
_store = store ?? throw new ArgumentNullException(nameof(store));
_expirationModelOptions = expirationModelOptions.Value;
_validationModelOptions = validationModelOptions.Value;
_logger = loggerFactory.CreateLogger <HttpCacheHeadersMiddleware>();
}
public HttpCacheHeaderWithExclusionsMiddleware(
RequestDelegate next,
ILoggerFactory loggerFactory,
IDateParser dateParser,
IValidatorValueStore store,
IStoreKeyGenerator storeKeyGenerator,
IETagGenerator eTagGenerator,
ILastModifiedInjector lastModifiedInjector,
IOptions <ExpirationModelOptions> expirationModelOptions,
IOptions <ValidationModelOptions> validationModelOptions,
IOptions <ExcludedRouteModelOptions> excludedRouteModelOptions)
{
if (loggerFactory == null)
{
throw new ArgumentNullException(nameof(loggerFactory));
}
if (validationModelOptions == null)
{
throw new ArgumentNullException(nameof(validationModelOptions));
}
if (expirationModelOptions == null)
{
throw new ArgumentNullException(nameof(expirationModelOptions));
}
_next = next ?? throw new ArgumentNullException(nameof(next));
_dateParser = dateParser ?? throw new ArgumentNullException(nameof(dateParser));
_store = store ?? throw new ArgumentNullException(nameof(store));
_storeKeyGenerator = storeKeyGenerator ?? throw new ArgumentNullException(nameof(storeKeyGenerator));
_eTagGenerator = eTagGenerator ?? throw new ArgumentNullException(nameof(eTagGenerator));
_lastModifiedInjector =
lastModifiedInjector ?? throw new ArgumentNullException(nameof(lastModifiedInjector));
_expirationModelOptions = expirationModelOptions.Value;
_validationModelOptions = validationModelOptions.Value;
_excludedRouteModelOptions = excludedRouteModelOptions.Value;
_logger = loggerFactory.CreateLogger <HttpCacheHeadersMiddleware>();
}
private async Task GenerateExpirationHeadersOnResponse(
HttpContext httpContext,
ExpirationModelOptions expirationModelOptions,
ValidationModelOptions validationModelOptions)
{
_logger.LogInformation("Generating expiration headers.");
var headers = httpContext.Response.Headers;
// remove current Expires & Cache-Control headers
headers.Remove(HeaderNames.Expires);
headers.Remove(HeaderNames.CacheControl);
// set expiration header (remove milliseconds)
var expires = DateTimeOffset
.UtcNow
.AddSeconds(expirationModelOptions.MaxAge);
var expiresValue = await _dateParser.ExpiresToString(expires);
headers[HeaderNames.Expires] = expiresValue;
var cacheControlHeaderValue = string.Format(
CultureInfo.InvariantCulture,
"{0},max-age={1}{2}{3}{4}{5}{6}{7}{8}",
expirationModelOptions.CacheLocation.ToString().ToLowerInvariant(),
expirationModelOptions.MaxAge,
expirationModelOptions.SharedMaxAge == null ? null : ",s-maxage=",
expirationModelOptions.SharedMaxAge,
expirationModelOptions.NoStore ? ",no-store" : null,
expirationModelOptions.NoTransform ? ",no-transform" : null,
validationModelOptions.NoCache ? ",no-cache" : null,
validationModelOptions.MustRevalidate ? ",must-revalidate" : null,
validationModelOptions.ProxyRevalidate ? ",proxy-revalidate" : null);
headers[HeaderNames.CacheControl] = cacheControlHeaderValue;
_logger.LogInformation(
$"Expiration headers generated. Expires: {expiresValue}. Cache-Control: {cacheControlHeaderValue}.");
}
private StoreKeyContext ConstructStoreKeyContext(HttpRequest request,
ValidationModelOptions validationModelOptions)
{
return(new StoreKeyContext(request, validationModelOptions.Vary, validationModelOptions.VaryByAll));
}
