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/*
Copyright (C) 2015 The Qt Company Ltd
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "DNSResolveQueue.h"
#include <QHostInfo>
#include <QObject>
#include <QString>
#include <wtf/text/WTFString.h>
namespace WebCore {
class DnsPrefetchHelper : public QObject {
Q_OBJECT
public:
DnsPrefetchHelper() : QObject() { }
public Q_SLOTS:
void lookup(QString hostname)
{
if (hostname.isEmpty()) {
DNSResolveQueue::shared().decrementRequestCount();
return; // this actually happens
}
QHostInfo::lookupHost(hostname, this, SLOT(lookedUp(QHostInfo)));
}
void lookedUp(const QHostInfo&)
{
// we do not cache the result, we throw it away.
// we currently rely on the OS to cache the results. If it does not do that
// then at least the ISP nameserver did it.
// Since Qt 4.6.3, Qt also has a small DNS cache.
DNSResolveQueue::shared().decrementRequestCount();
}
};
// This is called on mouse over a href and on page loading.
void prefetchDNS(const String& hostname)
{
if (hostname.isEmpty())
return;
DNSResolveQueue::shared().add(hostname);
}
bool DNSResolveQueue::platformProxyIsEnabledInSystemPreferences()
{
// Qt expects the system or a proxy to cache the result, but other platforms disable WebCore DNS prefetching when proxies are enabled.
return false;
}
// This is called by the platform-independent DNSResolveQueue.
void DNSResolveQueue::platformResolve(const String& hostname)
{
static DnsPrefetchHelper dnsPrefetchHelper;
dnsPrefetchHelper.lookup(QString(hostname));
}
} // namespace
#include "DNSQt.moc"
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