public void TryParseSeconds_Succeeds(string headerValues, string targetValue, int expectedValue)
{
TimeSpan?value;
Assert.True(HeaderUtilities.TryParseSeconds(new StringValues(headerValues), targetValue, out value));
Assert.Equal(TimeSpan.FromSeconds(expectedValue), value);
}
public virtual bool IsCachedEntryFresh(ResponseCachingContext context)
{
var age = context.CachedEntryAge !.Value;
var cachedCacheControlHeaders = context.CachedResponseHeaders.CacheControl;
var requestCacheControlHeaders = context.HttpContext.Request.Headers.CacheControl;
// Add min-fresh requirements
if (HeaderUtilities.TryParseSeconds(requestCacheControlHeaders, CacheControlHeaderValue.MinFreshString, out var minFresh))
{
age += minFresh.Value;
context.Logger.ExpirationMinFreshAdded(minFresh.Value);
}
// Validate shared max age, this overrides any max age settings for shared caches
TimeSpan?cachedSharedMaxAge;
HeaderUtilities.TryParseSeconds(cachedCacheControlHeaders, CacheControlHeaderValue.SharedMaxAgeString, out cachedSharedMaxAge);
if (age >= cachedSharedMaxAge)
{
// shared max age implies must revalidate
context.Logger.ExpirationSharedMaxAgeExceeded(age, cachedSharedMaxAge.Value);
return(false);
}
else if (!cachedSharedMaxAge.HasValue)
{
TimeSpan?requestMaxAge;
HeaderUtilities.TryParseSeconds(requestCacheControlHeaders, CacheControlHeaderValue.MaxAgeString, out requestMaxAge);
TimeSpan?cachedMaxAge;
HeaderUtilities.TryParseSeconds(cachedCacheControlHeaders, CacheControlHeaderValue.MaxAgeString, out cachedMaxAge);
var lowestMaxAge = cachedMaxAge < requestMaxAge ? cachedMaxAge : requestMaxAge ?? cachedMaxAge;
// Validate max age
if (age >= lowestMaxAge)
{
// Must revalidate or proxy revalidate
if (HeaderUtilities.ContainsCacheDirective(cachedCacheControlHeaders, CacheControlHeaderValue.MustRevalidateString) ||
HeaderUtilities.ContainsCacheDirective(cachedCacheControlHeaders, CacheControlHeaderValue.ProxyRevalidateString))
{
context.Logger.ExpirationMustRevalidate(age, lowestMaxAge.Value);
return(false);
}
TimeSpan?requestMaxStale;
var maxStaleExist = HeaderUtilities.ContainsCacheDirective(requestCacheControlHeaders, CacheControlHeaderValue.MaxStaleString);
HeaderUtilities.TryParseSeconds(requestCacheControlHeaders, CacheControlHeaderValue.MaxStaleString, out requestMaxStale);
// Request allows stale values with no age limit
if (maxStaleExist && !requestMaxStale.HasValue)
{
context.Logger.ExpirationInfiniteMaxStaleSatisfied(age, lowestMaxAge.Value);
return(true);
}
// Request allows stale values with age limit
if (requestMaxStale.HasValue && age - lowestMaxAge < requestMaxStale)
{
context.Logger.ExpirationMaxStaleSatisfied(age, lowestMaxAge.Value, requestMaxStale.Value);
return(true);
}
context.Logger.ExpirationMaxAgeExceeded(age, lowestMaxAge.Value);
return(false);
}
else if (!cachedMaxAge.HasValue && !requestMaxAge.HasValue)
{
// Validate expiration
DateTimeOffset expires;
if (HeaderUtilities.TryParseDate(context.CachedResponseHeaders.Expires.ToString(), out expires) &&
context.ResponseTime !.Value >= expires)
{
context.Logger.ExpirationExpiresExceeded(context.ResponseTime.Value, expires);
return(false);
}
}
}
return(true);
}
public void TryParseSeconds_Fails(string headerValues, string targetValue)
{
TimeSpan?value;
Assert.False(HeaderUtilities.TryParseSeconds(new StringValues(headerValues), targetValue, out value));
}