/** \fn MythDownloadManager::GetLastModified(const QString &url)
* \brief Gets the Last Modified timestamp for a URI
* \param url URI to test.
* \return Timestamp the URI was last modified or now if an error occurred
*/
QDateTime MythDownloadManager::GetLastModified(const QString &url)
{
static const char dateFormat[] = "ddd, dd MMM yyyy hh:mm:ss 'GMT'";
VERBOSE(VB_FILE+VB_EXTRA, LOC + QString("GetLastModified('%1')").arg(url));
QDateTime result;
QDateTime now = QDateTime::currentDateTime();
QNetworkCacheMetaData urlData = m_manager->cache()->metaData(QUrl(url));
if (urlData.isValid())
{
if (urlData.lastModified().secsTo(now) <= 60)
{
result = urlData.lastModified();
}
else
{
// If the last modification date is older than 60 seconds, and
// we loaded the page over 60 seconds ago, then redownload the
// page to re-verify it's last modified date.
QNetworkCacheMetaData::RawHeaderList headers =
urlData.rawHeaders();
bool found = false;
QNetworkCacheMetaData::RawHeaderList::iterator it
= headers.begin();
for (; !found && it != headers.end(); ++it)
{
if ((*it).first == "Date")
{
found = true;
QDateTime loadDate =
QDateTime::fromString((*it).second, dateFormat);
loadDate.setTimeSpec(Qt::UTC);
if (loadDate.secsTo(now) <= 60)
result = urlData.lastModified();
}
}
}
}
if (!result.isValid())
{
MythDownloadInfo *dlInfo = new MythDownloadInfo;
dlInfo->m_url = url;
dlInfo->m_syncMode = true;
if (downloadNow(dlInfo, false) && dlInfo->m_reply)
{
QVariant lastMod =
dlInfo->m_reply->header(QNetworkRequest::LastModifiedHeader);
if (lastMod.isValid())
result = lastMod.toDateTime();
}
delete dlInfo;
}
return result;
}
void QNetworkCacheMetaDataPrivate::save(QDataStream &out, const QNetworkCacheMetaData &metaData)
{
// note: if you change the contents of the meta data here
// remember to bump the cache version in qnetworkdiskcache.cpp CurrentCacheVersion
out << metaData.url();
out << metaData.expirationDate();
out << metaData.lastModified();
out << metaData.saveToDisk();
out << metaData.attributes();
out << metaData.rawHeaders();
}
void NetworkCache::clearCache(int period)
{
if (period <= 0)
{
clear();
emit cleared();
return;
}
const QDir cacheMainDirectory(cacheDirectory());
const QStringList directories(cacheMainDirectory.entryList(QDir::AllDirs | QDir::NoDotAndDotDot));
for (int i = 0; i < directories.count(); ++i)
{
const QDir cacheSubDirectory(cacheMainDirectory.absoluteFilePath(directories.at(i)));
const QStringList subDirectories(cacheSubDirectory.entryList(QDir::AllDirs | QDir::NoDotAndDotDot));
for (int j = 0; j < subDirectories.count(); ++j)
{
const QDir cacheFilesDirectory(cacheSubDirectory.absoluteFilePath(subDirectories.at(j)));
const QStringList files(cacheFilesDirectory.entryList(QDir::Files));
for (int k = 0; k < files.count(); ++k)
{
const QNetworkCacheMetaData metaData(fileMetaData(cacheFilesDirectory.absoluteFilePath(files.at(k))));
if (metaData.isValid() && metaData.lastModified().isValid() && metaData.lastModified().secsTo(QDateTime::currentDateTime()) > (period * 3600))
{
remove(metaData.url());
}
}
}
}
}
void tst_QNetworkCacheMetaData::qnetworkcachemetadata()
{
QNetworkCacheMetaData data;
QCOMPARE(data.expirationDate(), QDateTime());
QCOMPARE(data.isValid(), false);
QCOMPARE(data.lastModified(), QDateTime());
QCOMPARE(data.operator!=(QNetworkCacheMetaData()), false);
QNetworkCacheMetaData metaData;
QCOMPARE(data.operator=(metaData), QNetworkCacheMetaData());
QCOMPARE(data.operator==(QNetworkCacheMetaData()), true);
QCOMPARE(data.rawHeaders(), QNetworkCacheMetaData::RawHeaderList());
QCOMPARE(data.saveToDisk(), true);
QCOMPARE(data.url(), QUrl());
data.setExpirationDate(QDateTime());
data.setLastModified(QDateTime());
data.setRawHeaders(QNetworkCacheMetaData::RawHeaderList());
data.setSaveToDisk(false);
data.setUrl(QUrl());
}
int main(int argc, char **argv)
{
QCoreApplication application(argc, argv);
QCoreApplication::setOrganizationDomain(QLatin1String("sites.google.com/site/zeromusparadoxe01"));
QCoreApplication::setApplicationName(QLatin1String("zBrowser"));
QStringList args = application.arguments();
args.takeFirst();
if (args.isEmpty()) {
QTextStream stream(stdout);
stream << "zbrowser-cacheinfo is a tool for viewing and extracting information out of zBrowser cache files." << endl;
stream << "zbrowser-cacheinfo [-o cachefile] [file | url]" << endl;
return 0;
}
NetworkDiskCache diskCache;
QString location = QDesktopServices::storageLocation(QDesktopServices::CacheLocation)
+ QLatin1String("/browser/");
diskCache.setCacheDirectory(location);
QNetworkCacheMetaData metaData;
QString last = args.takeLast();
if (QFile::exists(last)) {
qDebug() << "Reading in from a file and not a URL.";
metaData = diskCache._fileMetaData(last);
} else {
qDebug() << "Reading in from a URL and not a file.";
metaData = diskCache.metaData(last);
}
if (!args.isEmpty()
&& args.count() >= 1
&& args.first() == QLatin1String("-o")) {
QUrl url = metaData.url();
QIODevice *device = diskCache.data(url);
if (!device) {
qDebug() << "Error: data for URL is 0!";
return 1;
}
QString fileName;
if (args.count() == 2) {
fileName = args.last();
} else {
QFileInfo info(url.path());
fileName = info.fileName();
if (fileName.isEmpty()) {
qDebug() << "URL file name is empty, please specify an output file, I wont guess.";
return 1;
}
if (QFile::exists(fileName)) {
qDebug() << "File already exists, not overwriting, please specify an output file.";
return 1;
}
}
qDebug() << "Saved cache file to:" << fileName;
QFile file(fileName);
if (!file.open(QFile::ReadWrite))
qDebug() << "Unable to open the output file for writing.";
else
file.write(device->readAll());
delete device;
}
QTextStream stream(stdout);
stream << "URL: " << metaData.url().toString() << endl;
stream << "Expiration Date: " << metaData.expirationDate().toString() << endl;
stream << "Last Modified Date: " << metaData.lastModified().toString() << endl;
stream << "Save to disk: " << metaData.saveToDisk() << endl;
stream << "Headers:" << endl;
foreach (const QNetworkCacheMetaData::RawHeader &header, metaData.rawHeaders())
stream << "\t" << header.first << ": " << header.second << endl;
QIODevice *device = diskCache.data(metaData.url());
if (device) {
stream << "Data Size: " << device->size() << endl;
stream << "First line: " << device->readLine(100);
} else {
stream << "No data? Either the file is corrupt or there is an error." << endl;
}
delete device;
return 0;
}
/*
For a given httpRequest
1) If AlwaysNetwork, return
2) If we have a cache entry for this url populate headers so the server can return 304
3) Calculate if response_is_fresh and if so send the cache and set loadedFromCache to true
*/
void QNetworkAccessHttpBackend::validateCache(QHttpNetworkRequest &httpRequest, bool &loadedFromCache)
{
QNetworkRequest::CacheLoadControl CacheLoadControlAttribute =
(QNetworkRequest::CacheLoadControl)request().attribute(QNetworkRequest::CacheLoadControlAttribute, QNetworkRequest::PreferNetwork).toInt();
if (CacheLoadControlAttribute == QNetworkRequest::AlwaysNetwork) {
// forced reload from the network
// tell any caching proxy servers to reload too
httpRequest.setHeaderField("Cache-Control", "no-cache");
httpRequest.setHeaderField("Pragma", "no-cache");
return;
}
QAbstractNetworkCache *nc = networkCache();
if (!nc)
return; // no local cache
QNetworkCacheMetaData metaData = nc->metaData(url());
if (!metaData.isValid())
return; // not in cache
if (!metaData.saveToDisk())
return;
QNetworkHeadersPrivate cacheHeaders;
QNetworkHeadersPrivate::RawHeadersList::ConstIterator it;
cacheHeaders.setAllRawHeaders(metaData.rawHeaders());
it = cacheHeaders.findRawHeader("etag");
if (it != cacheHeaders.rawHeaders.constEnd())
httpRequest.setHeaderField("If-None-Match", it->second);
QDateTime lastModified = metaData.lastModified();
if (lastModified.isValid())
httpRequest.setHeaderField("If-Modified-Since", QNetworkHeadersPrivate::toHttpDate(lastModified));
it = cacheHeaders.findRawHeader("Cache-Control");
if (it != cacheHeaders.rawHeaders.constEnd()) {
QHash<QByteArray, QByteArray> cacheControl = parseHttpOptionHeader(it->second);
if (cacheControl.contains("must-revalidate"))
return;
}
/*
* age_value
* is the value of Age: header received by the cache with
* this response.
* date_value
* is the value of the origin server's Date: header
* request_time
* is the (local) time when the cache made the request
* that resulted in this cached response
* response_time
* is the (local) time when the cache received the
* response
* now
* is the current (local) time
*/
QDateTime currentDateTime = QDateTime::currentDateTime();
int age_value = 0;
it = cacheHeaders.findRawHeader("age");
if (it != cacheHeaders.rawHeaders.constEnd())
age_value = QNetworkHeadersPrivate::fromHttpDate(it->second).toTime_t();
int date_value = 0;
it = cacheHeaders.findRawHeader("date");
if (it != cacheHeaders.rawHeaders.constEnd())
date_value = QNetworkHeadersPrivate::fromHttpDate(it->second).toTime_t();
int now = currentDateTime.toUTC().toTime_t();
int request_time = now;
int response_time = now;
int apparent_age = qMax(0, response_time - date_value);
int corrected_received_age = qMax(apparent_age, age_value);
int response_delay = response_time - request_time;
int corrected_initial_age = corrected_received_age + response_delay;
int resident_time = now - response_time;
int current_age = corrected_initial_age + resident_time;
// RFC 2616 13.2.4 Expiration Calculations
QDateTime expirationDate = metaData.expirationDate();
if (!expirationDate.isValid()) {
if (lastModified.isValid()) {
int diff = currentDateTime.secsTo(lastModified);
expirationDate = lastModified;
expirationDate.addSecs(diff / 10);
if (httpRequest.headerField("Warning").isEmpty()) {
QDateTime dt;
dt.setTime_t(current_age);
if (dt.daysTo(currentDateTime) > 1)
httpRequest.setHeaderField("Warning", "113");
}
}
}
int freshness_lifetime = currentDateTime.secsTo(expirationDate);
bool response_is_fresh = (freshness_lifetime > current_age);
if (!response_is_fresh && CacheLoadControlAttribute == QNetworkRequest::PreferNetwork)
return;
loadedFromCache = true;
#if defined(QNETWORKACCESSHTTPBACKEND_DEBUG)
qDebug() << "response_is_fresh" << CacheLoadControlAttribute;
#endif
if (!sendCacheContents(metaData))
loadedFromCache = false;
}
/*
For a given httpRequest
1) If AlwaysNetwork, return
2) If we have a cache entry for this url populate headers so the server can return 304
3) Calculate if response_is_fresh and if so send the cache and set loadedFromCache to true
*/
bool QNetworkAccessHttpBackend::loadFromCacheIfAllowed(QHttpNetworkRequest &httpRequest)
{
QNetworkRequest::CacheLoadControl CacheLoadControlAttribute =
(QNetworkRequest::CacheLoadControl)request().attribute(QNetworkRequest::CacheLoadControlAttribute, QNetworkRequest::PreferNetwork).toInt();
if (CacheLoadControlAttribute == QNetworkRequest::AlwaysNetwork) {
// If the request does not already specify preferred cache-control
// force reload from the network and tell any caching proxy servers to reload too
if (!request().rawHeaderList().contains("Cache-Control")) {
httpRequest.setHeaderField("Cache-Control", "no-cache");
httpRequest.setHeaderField("Pragma", "no-cache");
}
return false;
}
// The disk cache API does not currently support partial content retrieval.
// That is why we don't use the disk cache for any such requests.
if (request().hasRawHeader("Range"))
return false;
QAbstractNetworkCache *nc = networkCache();
if (!nc)
return false; // no local cache
QNetworkCacheMetaData metaData = nc->metaData(url());
if (!metaData.isValid())
return false; // not in cache
if (!metaData.saveToDisk())
return false;
QNetworkHeadersPrivate cacheHeaders;
QNetworkHeadersPrivate::RawHeadersList::ConstIterator it;
cacheHeaders.setAllRawHeaders(metaData.rawHeaders());
it = cacheHeaders.findRawHeader("etag");
if (it != cacheHeaders.rawHeaders.constEnd())
httpRequest.setHeaderField("If-None-Match", it->second);
QDateTime lastModified = metaData.lastModified();
if (lastModified.isValid())
httpRequest.setHeaderField("If-Modified-Since", QNetworkHeadersPrivate::toHttpDate(lastModified));
it = cacheHeaders.findRawHeader("Cache-Control");
if (it != cacheHeaders.rawHeaders.constEnd()) {
QHash<QByteArray, QByteArray> cacheControl = parseHttpOptionHeader(it->second);
if (cacheControl.contains("must-revalidate"))
return false;
}
QDateTime currentDateTime = QDateTime::currentDateTime();
QDateTime expirationDate = metaData.expirationDate();
#if 0
/*
* age_value
* is the value of Age: header received by the cache with
* this response.
* date_value
* is the value of the origin server's Date: header
* request_time
* is the (local) time when the cache made the request
* that resulted in this cached response
* response_time
* is the (local) time when the cache received the
* response
* now
* is the current (local) time
*/
int age_value = 0;
it = cacheHeaders.findRawHeader("age");
if (it != cacheHeaders.rawHeaders.constEnd())
age_value = it->second.toInt();
QDateTime dateHeader;
int date_value = 0;
it = cacheHeaders.findRawHeader("date");
if (it != cacheHeaders.rawHeaders.constEnd()) {
dateHeader = QNetworkHeadersPrivate::fromHttpDate(it->second);
date_value = dateHeader.toTime_t();
}
int now = currentDateTime.toUTC().toTime_t();
int request_time = now;
int response_time = now;
// Algorithm from RFC 2616 section 13.2.3
int apparent_age = qMax(0, response_time - date_value);
int corrected_received_age = qMax(apparent_age, age_value);
int response_delay = response_time - request_time;
int corrected_initial_age = corrected_received_age + response_delay;
int resident_time = now - response_time;
int current_age = corrected_initial_age + resident_time;
// RFC 2616 13.2.4 Expiration Calculations
if (!expirationDate.isValid()) {
if (lastModified.isValid()) {
int diff = currentDateTime.secsTo(lastModified);
expirationDate = lastModified;
expirationDate.addSecs(diff / 10);
if (httpRequest.headerField("Warning").isEmpty()) {
QDateTime dt;
dt.setTime_t(current_age);
if (dt.daysTo(currentDateTime) > 1)
httpRequest.setHeaderField("Warning", "113");
}
}
}
// the cache-saving code below sets the expirationDate with date+max_age
// if "max-age" is present, or to Expires otherwise
int freshness_lifetime = dateHeader.secsTo(expirationDate);
bool response_is_fresh = (freshness_lifetime > current_age);
#else
bool response_is_fresh = currentDateTime.secsTo(expirationDate) >= 0;
#endif
if (!response_is_fresh)
return false;
#if defined(QNETWORKACCESSHTTPBACKEND_DEBUG)
qDebug() << "response_is_fresh" << CacheLoadControlAttribute;
#endif
return sendCacheContents(metaData);
}
