PRBool
nsHttpResponseHead::ExpiresInPast()
{
PRUint32 expiresVal, dateVal;
return NS_SUCCEEDED(GetExpiresValue(&expiresVal)) &&
NS_SUCCEEDED(GetDateValue(&dateVal)) &&
expiresVal < dateVal;
}
bool
nsHttpResponseHead::ExpiresInPast() const
{
uint32_t maxAgeVal, expiresVal, dateVal;
// Bug #203271. Ensure max-age directive takes precedence over Expires
if (NS_SUCCEEDED(GetMaxAgeValue(&maxAgeVal))) {
return false;
}
return NS_SUCCEEDED(GetExpiresValue(&expiresVal)) &&
NS_SUCCEEDED(GetDateValue(&dateVal)) &&
expiresVal < dateVal;
}
// From section 13.2.4 of RFC2616, we compute the freshness lifetime of a cached
// response as follows:
//
// freshnessLifetime = max_age_value
// <or>
// freshnessLifetime = expires_value - date_value
// <or>
// freshnessLifetime = (date_value - last_modified_value) * 0.10
// <or>
// freshnessLifetime = 0
//
nsresult
nsHttpResponseHead::ComputeFreshnessLifetime(uint32_t *result) const
{
*result = 0;
// Try HTTP/1.1 style max-age directive...
if (NS_SUCCEEDED(GetMaxAgeValue(result)))
return NS_OK;
*result = 0;
uint32_t date = 0, date2 = 0;
if (NS_FAILED(GetDateValue(&date)))
date = NowInSeconds(); // synthesize a date header if none exists
// Try HTTP/1.0 style expires header...
if (NS_SUCCEEDED(GetExpiresValue(&date2))) {
if (date2 > date)
*result = date2 - date;
// the Expires header can specify a date in the past.
return NS_OK;
}
// Fallback on heuristic using last modified header...
if (NS_SUCCEEDED(GetLastModifiedValue(&date2))) {
LOG(("using last-modified to determine freshness-lifetime\n"));
LOG(("last-modified = %u, date = %u\n", date2, date));
if (date2 <= date) {
// this only makes sense if last-modified is actually in the past
*result = (date - date2) / 10;
return NS_OK;
}
}
// These responses can be cached indefinitely.
if ((mStatus == 300) || nsHttp::IsPermanentRedirect(mStatus)) {
*result = uint32_t(-1);
return NS_OK;
}
LOG(("nsHttpResponseHead::ComputeFreshnessLifetime [this = %x] "
"Insufficient information to compute a non-zero freshness "
"lifetime!\n", this));
return NS_OK;
}