/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtNetwork module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 3 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL3 included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 3 requirements ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 2.0 or (at your option) the GNU General ** Public license version 3 or any later version approved by the KDE Free ** Qt Foundation. The licenses are as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 ** included in the packaging of this file. Please review the following ** information to ensure the GNU General Public License requirements will ** be met: https://www.gnu.org/licenses/gpl-2.0.html and ** https://www.gnu.org/licenses/gpl-3.0.html. ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #include "qhostinfo.h" #include "qhostinfo_p.h" #include "QtCore/qscopedpointer.h" #include #include #include #include #include #include #include #include #ifdef Q_OS_UNIX # include #endif QT_BEGIN_NAMESPACE //#define QHOSTINFO_DEBUG Q_GLOBAL_STATIC(QHostInfoLookupManager, theHostInfoLookupManager) namespace { struct ToBeLookedUpEquals { typedef bool result_type; explicit ToBeLookedUpEquals(const QString &toBeLookedUp) Q_DECL_NOTHROW : m_toBeLookedUp(toBeLookedUp) {} result_type operator()(QHostInfoRunnable* lookup) const Q_DECL_NOTHROW { return m_toBeLookedUp == lookup->toBeLookedUp; } private: QString m_toBeLookedUp; }; // ### C++11: remove once we can use std::any_of() template bool any_of(InputIt first, InputIt last, UnaryPredicate p) { return std::find_if(first, last, p) != last; } template std::pair separate_if(InputIt first, InputIt last, OutputIt1 dest1, OutputIt2 dest2, UnaryPredicate p) { while (first != last) { if (p(*first)) { *dest1 = *first; ++dest1; } else { *dest2 = *first; ++dest2; } ++first; } return std::make_pair(dest1, dest2); } int get_signal_index() { static auto senderMetaObject = &QHostInfoResult::staticMetaObject; static auto signal = &QHostInfoResult::resultsReady; int signal_index = -1; void *args[] = { &signal_index, &signal }; senderMetaObject->static_metacall(QMetaObject::IndexOfMethod, 0, args); return signal_index + QMetaObjectPrivate::signalOffset(senderMetaObject); } void emit_results_ready(const QHostInfo &hostInfo, const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj) { static const int signal_index = get_signal_index(); auto result = new QHostInfoResult(receiver, slotObj); Q_CHECK_PTR(result); const int nargs = 2; auto types = reinterpret_cast(malloc(nargs * sizeof(int))); Q_CHECK_PTR(types); types[0] = QMetaType::type("void"); types[1] = QMetaType::type("QHostInfo"); auto args = reinterpret_cast(malloc(nargs * sizeof(void *))); Q_CHECK_PTR(args); args[0] = 0; args[1] = QMetaType::create(types[1], &hostInfo); Q_CHECK_PTR(args[1]); auto metaCallEvent = new QMetaCallEvent(slotObj, nullptr, signal_index, nargs, types, args); Q_CHECK_PTR(metaCallEvent); qApp->postEvent(result, metaCallEvent); } } /*! \class QHostInfo \brief The QHostInfo class provides static functions for host name lookups. \reentrant \inmodule QtNetwork \ingroup network QHostInfo uses the lookup mechanisms provided by the operating system to find the IP address(es) associated with a host name, or the host name associated with an IP address. The class provides two static convenience functions: one that works asynchronously and emits a signal once the host is found, and one that blocks and returns a QHostInfo object. To look up a host's IP addresses asynchronously, call lookupHost(), which takes the host name or IP address, a receiver object, and a slot signature as arguments and returns an ID. You can abort the lookup by calling abortHostLookup() with the lookup ID. Example: \snippet code/src_network_kernel_qhostinfo.cpp 0 The slot is invoked when the results are ready. The results are stored in a QHostInfo object. Call addresses() to get the list of IP addresses for the host, and hostName() to get the host name that was looked up. If the lookup failed, error() returns the type of error that occurred. errorString() gives a human-readable description of the lookup error. If you want a blocking lookup, use the QHostInfo::fromName() function: \snippet code/src_network_kernel_qhostinfo.cpp 1 QHostInfo supports Internationalized Domain Names (IDNs) through the IDNA and Punycode standards. To retrieve the name of the local host, use the static QHostInfo::localHostName() function. \note Since Qt 4.6.1 QHostInfo is using multiple threads for DNS lookup instead of one dedicated DNS thread. This improves performance, but also changes the order of signal emissions when using lookupHost() compared to previous versions of Qt. \note Since Qt 4.6.3 QHostInfo is using a small internal 60 second DNS cache for performance improvements. \sa QAbstractSocket, {http://www.rfc-editor.org/rfc/rfc3492.txt}{RFC 3492} */ static int nextId() { static QBasicAtomicInt counter = Q_BASIC_ATOMIC_INITIALIZER(0); return 1 + counter.fetchAndAddRelaxed(1); } /*! Looks up the IP address(es) associated with host name \a name, and returns an ID for the lookup. When the result of the lookup is ready, the slot or signal \a member in \a receiver is called with a QHostInfo argument. The QHostInfo object can then be inspected to get the results of the lookup. The lookup is performed by a single function call, for example: \snippet code/src_network_kernel_qhostinfo.cpp 2 The implementation of the slot prints basic information about the addresses returned by the lookup, or reports an error if it failed: \snippet code/src_network_kernel_qhostinfo.cpp 3 If you pass a literal IP address to \a name instead of a host name, QHostInfo will search for the domain name for the IP (i.e., QHostInfo will perform a \e reverse lookup). On success, the resulting QHostInfo will contain both the resolved domain name and IP addresses for the host name. Example: \snippet code/src_network_kernel_qhostinfo.cpp 4 \note There is no guarantee on the order the signals will be emitted if you start multiple requests with lookupHost(). \sa abortHostLookup(), addresses(), error(), fromName() */ int QHostInfo::lookupHost(const QString &name, QObject *receiver, const char *member) { #if defined QHOSTINFO_DEBUG qDebug("QHostInfo::lookupHost(\"%s\", %p, %s)", name.toLatin1().constData(), receiver, member ? member + 1 : 0); #endif if (!QAbstractEventDispatcher::instance(QThread::currentThread())) { qWarning("QHostInfo::lookupHost() called with no event dispatcher"); return -1; } qRegisterMetaType(); int id = nextId(); // generate unique ID if (name.isEmpty()) { if (!receiver) return -1; QHostInfo hostInfo(id); hostInfo.setError(QHostInfo::HostNotFound); hostInfo.setErrorString(QCoreApplication::translate("QHostInfo", "No host name given")); QScopedPointer result(new QHostInfoResult); QObject::connect(result.data(), SIGNAL(resultsReady(QHostInfo)), receiver, member, Qt::QueuedConnection); result.data()->emitResultsReady(hostInfo); return id; } QHostInfoLookupManager *manager = theHostInfoLookupManager(); if (manager) { // the application is still alive if (manager->cache.isEnabled()) { // check cache first bool valid = false; QHostInfo info = manager->cache.get(name, &valid); if (valid) { if (!receiver) return -1; info.setLookupId(id); QHostInfoResult result; QObject::connect(&result, SIGNAL(resultsReady(QHostInfo)), receiver, member, Qt::QueuedConnection); result.emitResultsReady(info); return id; } } // cache is not enabled or it was not in the cache, do normal lookup QHostInfoRunnable* runnable = new QHostInfoRunnable(name, id); if (receiver) QObject::connect(&runnable->resultEmitter, SIGNAL(resultsReady(QHostInfo)), receiver, member, Qt::QueuedConnection); manager->scheduleLookup(runnable); } return id; } /*! \fn QHostInfo &QHostInfo::operator=(QHostInfo &&other) Move-assigns \a other to this QHostInfo instance. \note The moved-from object \a other is placed in a partially-formed state, in which the only valid operations are destruction and assignment of a new value. \since 5.10 */ /*! \fn void QHostInfo::swap(QHostInfo &other) Swaps host-info \a other with this host-info. This operation is very fast and never fails. \since 5.10 */ /*! \fn template int QHostInfo::lookupHost(const QString &name, const QObject *receiver, PointerToMemberFunction function) \since 5.9 \overload Looks up the IP address(es) associated with host name \a name, and returns an ID for the lookup. When the result of the lookup is ready, the slot or signal \a function in \a receiver is called with a QHostInfo argument. The QHostInfo object can then be inspected to get the results of the lookup. \note There is no guarantee on the order the signals will be emitted if you start multiple requests with lookupHost(). \sa abortHostLookup(), addresses(), error(), fromName() */ /*! \fn template int QHostInfo::lookupHost(const QString &name, Functor functor) \since 5.9 \overload Looks up the IP address(es) associated with host name \a name, and returns an ID for the lookup. When the result of the lookup is ready, the \a functor is called with a QHostInfo argument. The QHostInfo object can then be inspected to get the results of the lookup. \note There is no guarantee on the order the signals will be emitted if you start multiple requests with lookupHost(). \sa abortHostLookup(), addresses(), error(), fromName() */ /*! \fn template int QHostInfo::lookupHost(const QString &name, const QObject *context, Functor functor) \since 5.9 \overload Looks up the IP address(es) associated with host name \a name, and returns an ID for the lookup. When the result of the lookup is ready, the \a functor is called with a QHostInfo argument. The QHostInfo object can then be inspected to get the results of the lookup. If \a context is destroyed before the lookup completes, the \a functor will not be called. The \a functor will be run in the thread of \a context. The context's thread must have a running Qt event loop. \note There is no guarantee on the order the signals will be emitted if you start multiple requests with lookupHost(). \sa abortHostLookup(), addresses(), error(), fromName() */ /*! Aborts the host lookup with the ID \a id, as returned by lookupHost(). \sa lookupHost(), lookupId() */ void QHostInfo::abortHostLookup(int id) { theHostInfoLookupManager()->abortLookup(id); } /*! Looks up the IP address(es) for the given host \a name. The function blocks during the lookup which means that execution of the program is suspended until the results of the lookup are ready. Returns the result of the lookup in a QHostInfo object. If you pass a literal IP address to \a name instead of a host name, QHostInfo will search for the domain name for the IP (i.e., QHostInfo will perform a \e reverse lookup). On success, the returned QHostInfo will contain both the resolved domain name and IP addresses for the host name. \sa lookupHost() */ QHostInfo QHostInfo::fromName(const QString &name) { #if defined QHOSTINFO_DEBUG qDebug("QHostInfo::fromName(\"%s\")",name.toLatin1().constData()); #endif QHostInfo hostInfo = QHostInfoAgent::fromName(name); QAbstractHostInfoLookupManager* manager = theHostInfoLookupManager(); manager->cache.put(name, hostInfo); return hostInfo; } #ifndef QT_NO_BEARERMANAGEMENT QHostInfo QHostInfoPrivate::fromName(const QString &name, QSharedPointer session) { #if defined QHOSTINFO_DEBUG qDebug("QHostInfoPrivate::fromName(\"%s\") with session %p",name.toLatin1().constData(), session.data()); #endif QHostInfo hostInfo = QHostInfoAgent::fromName(name, session); QAbstractHostInfoLookupManager* manager = theHostInfoLookupManager(); manager->cache.put(name, hostInfo); return hostInfo; } #endif #ifndef QT_NO_BEARERMANAGEMENT QHostInfo QHostInfoAgent::fromName(const QString &hostName, QSharedPointer) { return QHostInfoAgent::fromName(hostName); } #endif /*! \enum QHostInfo::HostInfoError This enum describes the various errors that can occur when trying to resolve a host name. \value NoError The lookup was successful. \value HostNotFound No IP addresses were found for the host. \value UnknownError An unknown error occurred. \sa error(), setError() */ /*! Constructs an empty host info object with lookup ID \a id. \sa lookupId() */ QHostInfo::QHostInfo(int id) : d(new QHostInfoPrivate) { d->lookupId = id; } /*! Constructs a copy of \a other. */ QHostInfo::QHostInfo(const QHostInfo &other) : d(new QHostInfoPrivate(*other.d.data())) { } /*! Assigns the data of the \a other object to this host info object, and returns a reference to it. */ QHostInfo &QHostInfo::operator=(const QHostInfo &other) { *d.data() = *other.d.data(); return *this; } /*! Destroys the host info object. */ QHostInfo::~QHostInfo() { } /*! Returns the list of IP addresses associated with hostName(). This list may be empty. Example: \snippet code/src_network_kernel_qhostinfo.cpp 5 \sa hostName(), error() */ QList QHostInfo::addresses() const { return d->addrs; } /*! Sets the list of addresses in this QHostInfo to \a addresses. \sa addresses() */ void QHostInfo::setAddresses(const QList &addresses) { d->addrs = addresses; } /*! Returns the name of the host whose IP addresses were looked up. \sa localHostName() */ QString QHostInfo::hostName() const { return d->hostName; } /*! Sets the host name of this QHostInfo to \a hostName. \sa hostName() */ void QHostInfo::setHostName(const QString &hostName) { d->hostName = hostName; } /*! Returns the type of error that occurred if the host name lookup failed; otherwise returns NoError. \sa setError(), errorString() */ QHostInfo::HostInfoError QHostInfo::error() const { return d->err; } /*! Sets the error type of this QHostInfo to \a error. \sa error(), errorString() */ void QHostInfo::setError(HostInfoError error) { d->err = error; } /*! Returns the ID of this lookup. \sa setLookupId(), abortHostLookup(), hostName() */ int QHostInfo::lookupId() const { return d->lookupId; } /*! Sets the ID of this lookup to \a id. \sa lookupId(), lookupHost() */ void QHostInfo::setLookupId(int id) { d->lookupId = id; } /*! If the lookup failed, this function returns a human readable description of the error; otherwise "Unknown error" is returned. \sa setErrorString(), error() */ QString QHostInfo::errorString() const { return d->errorStr; } /*! Sets the human readable description of the error that occurred to \a str if the lookup failed. \sa errorString(), setError() */ void QHostInfo::setErrorString(const QString &str) { d->errorStr = str; } /*! \fn QString QHostInfo::localHostName() Returns this machine's host name, if one is configured. Note that hostnames are not guaranteed to be globally unique, especially if they were configured automatically. This function does not guarantee the returned host name is a Fully Qualified Domain Name (FQDN). For that, use fromName() to resolve the returned name to an FQDN. This function returns the same as QSysInfo::machineHostName(). \sa hostName(), localDomainName() */ QString QHostInfo::localHostName() { return QSysInfo::machineHostName(); } /*! \fn QString QHostInfo::localDomainName() Returns the DNS domain of this machine. \note DNS domains are not related to domain names found in Windows networks. \sa hostName() */ int QHostInfo::lookupHostImpl(const QString &name, const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj) { #if defined QHOSTINFO_DEBUG qDebug("QHostInfo::lookupHost(\"%s\", %p, %p)", name.toLatin1().constData(), receiver, slotObj); #endif if (!QAbstractEventDispatcher::instance(QThread::currentThread())) { qWarning("QHostInfo::lookupHost() called with no event dispatcher"); return -1; } qRegisterMetaType(); int id = nextId(); // generate unique ID if (Q_UNLIKELY(name.isEmpty())) { QHostInfo hostInfo(id); hostInfo.setError(QHostInfo::HostNotFound); hostInfo.setErrorString(QCoreApplication::translate("QHostInfo", "No host name given")); emit_results_ready(hostInfo, receiver, slotObj); return id; } QHostInfoLookupManager *manager = theHostInfoLookupManager(); if (Q_LIKELY(manager)) { // the application is still alive if (manager->cache.isEnabled()) { // check cache first bool valid = false; QHostInfo info = manager->cache.get(name, &valid); if (valid) { info.setLookupId(id); emit_results_ready(info, receiver, slotObj); return id; } } // cache is not enabled or it was not in the cache, do normal lookup QHostInfoRunnable* runnable = new QHostInfoRunnable(name, id, receiver, slotObj); manager->scheduleLookup(runnable); } return id; } QHostInfoRunnable::QHostInfoRunnable(const QString &hn, int i) : toBeLookedUp(hn), id(i) { setAutoDelete(true); } QHostInfoRunnable::QHostInfoRunnable(const QString &hn, int i, const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj) : toBeLookedUp(hn), id(i), resultEmitter(receiver, slotObj) { setAutoDelete(true); } // the QHostInfoLookupManager will at some point call this via a QThreadPool void QHostInfoRunnable::run() { QHostInfoLookupManager *manager = theHostInfoLookupManager(); // check aborted if (manager->wasAborted(id)) { manager->lookupFinished(this); return; } QHostInfo hostInfo; // QHostInfo::lookupHost already checks the cache. However we need to check // it here too because it might have been cache saved by another QHostInfoRunnable // in the meanwhile while this QHostInfoRunnable was scheduled but not running if (manager->cache.isEnabled()) { // check the cache first bool valid = false; hostInfo = manager->cache.get(toBeLookedUp, &valid); if (!valid) { // not in cache, we need to do the lookup and store the result in the cache hostInfo = QHostInfoAgent::fromName(toBeLookedUp); manager->cache.put(toBeLookedUp, hostInfo); } } else { // cache is not enabled, just do the lookup and continue hostInfo = QHostInfoAgent::fromName(toBeLookedUp); } // check aborted again if (manager->wasAborted(id)) { manager->lookupFinished(this); return; } // signal emission hostInfo.setLookupId(id); resultEmitter.emitResultsReady(hostInfo); #if QT_CONFIG(thread) // now also iterate through the postponed ones { QMutexLocker locker(&manager->mutex); const auto partitionBegin = std::stable_partition(manager->postponedLookups.rbegin(), manager->postponedLookups.rend(), ToBeLookedUpEquals(toBeLookedUp)).base(); const auto partitionEnd = manager->postponedLookups.end(); for (auto it = partitionBegin; it != partitionEnd; ++it) { QHostInfoRunnable* postponed = *it; // we can now emit hostInfo.setLookupId(postponed->id); postponed->resultEmitter.emitResultsReady(hostInfo); delete postponed; } manager->postponedLookups.erase(partitionBegin, partitionEnd); } #endif manager->lookupFinished(this); // thread goes back to QThreadPool } QHostInfoLookupManager::QHostInfoLookupManager() : mutex(QMutex::Recursive), wasDeleted(false) { moveToThread(QCoreApplicationPrivate::mainThread()); #if QT_CONFIG(thread) connect(QCoreApplication::instance(), SIGNAL(destroyed()), SLOT(waitForThreadPoolDone()), Qt::DirectConnection); threadPool.setMaxThreadCount(20); // do up to 20 DNS lookups in parallel #endif } QHostInfoLookupManager::~QHostInfoLookupManager() { wasDeleted = true; // don't qDeleteAll currentLookups, the QThreadPool has ownership clear(); } void QHostInfoLookupManager::clear() { { QMutexLocker locker(&mutex); qDeleteAll(scheduledLookups); qDeleteAll(finishedLookups); #if QT_CONFIG(thread) qDeleteAll(postponedLookups); postponedLookups.clear(); #endif scheduledLookups.clear(); finishedLookups.clear(); } #if QT_CONFIG(thread) threadPool.waitForDone(); #endif cache.clear(); } void QHostInfoLookupManager::work() { if (wasDeleted) return; // goals of this function: // - launch new lookups via the thread pool // - make sure only one lookup per host/IP is in progress QMutexLocker locker(&mutex); if (!finishedLookups.isEmpty()) { // remove ID from aborted if it is in there for (int i = 0; i < finishedLookups.length(); i++) { abortedLookups.removeAll(finishedLookups.at(i)->id); } finishedLookups.clear(); } #if QT_CONFIG(thread) auto isAlreadyRunning = [this](QHostInfoRunnable *lookup) { return any_of(currentLookups.cbegin(), currentLookups.cend(), ToBeLookedUpEquals(lookup->toBeLookedUp)); }; // Transfer any postponed lookups that aren't currently running to the scheduled list, keeping already-running lookups: postponedLookups.erase(separate_if(postponedLookups.begin(), postponedLookups.end(), postponedLookups.begin(), std::front_inserter(scheduledLookups), // prepend! we want to finish it ASAP isAlreadyRunning).first, postponedLookups.end()); // Unschedule and postpone any that are currently running: scheduledLookups.erase(separate_if(scheduledLookups.begin(), scheduledLookups.end(), std::back_inserter(postponedLookups), scheduledLookups.begin(), isAlreadyRunning).second, scheduledLookups.end()); const int availableThreads = threadPool.maxThreadCount() - currentLookups.size(); if (availableThreads > 0) { int readyToStartCount = qMin(availableThreads, scheduledLookups.size()); auto it = scheduledLookups.begin(); while (readyToStartCount--) { // runnable now running in new thread, track this in currentLookups threadPool.start(*it); currentLookups.push_back(std::move(*it)); ++it; } scheduledLookups.erase(scheduledLookups.begin(), it); } #else if (!scheduledLookups.isEmpty()) scheduledLookups.takeFirst()->run(); #endif } // called by QHostInfo void QHostInfoLookupManager::scheduleLookup(QHostInfoRunnable *r) { if (wasDeleted) return; QMutexLocker locker(&this->mutex); scheduledLookups.enqueue(r); work(); } // called by QHostInfo void QHostInfoLookupManager::abortLookup(int id) { if (wasDeleted) return; QMutexLocker locker(&this->mutex); #if QT_CONFIG(thread) // is postponed? delete and return for (int i = 0; i < postponedLookups.length(); i++) { if (postponedLookups.at(i)->id == id) { delete postponedLookups.takeAt(i); return; } } #endif // is scheduled? delete and return for (int i = 0; i < scheduledLookups.length(); i++) { if (scheduledLookups.at(i)->id == id) { delete scheduledLookups.takeAt(i); return; } } if (!abortedLookups.contains(id)) abortedLookups.append(id); } // called from QHostInfoRunnable bool QHostInfoLookupManager::wasAborted(int id) { if (wasDeleted) return true; QMutexLocker locker(&this->mutex); return abortedLookups.contains(id); } // called from QHostInfoRunnable void QHostInfoLookupManager::lookupFinished(QHostInfoRunnable *r) { if (wasDeleted) return; QMutexLocker locker(&this->mutex); #if QT_CONFIG(thread) currentLookups.removeOne(r); #endif finishedLookups.append(r); work(); } // This function returns immediately when we had a result in the cache, else it will later emit a signal QHostInfo qt_qhostinfo_lookup(const QString &name, QObject *receiver, const char *member, bool *valid, int *id) { *valid = false; *id = -1; // check cache QAbstractHostInfoLookupManager* manager = theHostInfoLookupManager(); if (manager && manager->cache.isEnabled()) { QHostInfo info = manager->cache.get(name, valid); if (*valid) { return info; } } // was not in cache, trigger lookup *id = QHostInfo::lookupHost(name, receiver, member); // return empty response, valid==false return QHostInfo(); } void qt_qhostinfo_clear_cache() { QAbstractHostInfoLookupManager* manager = theHostInfoLookupManager(); if (manager) { manager->clear(); } } #ifdef QT_BUILD_INTERNAL void Q_AUTOTEST_EXPORT qt_qhostinfo_enable_cache(bool e) { QAbstractHostInfoLookupManager* manager = theHostInfoLookupManager(); if (manager) { manager->cache.setEnabled(e); } } void qt_qhostinfo_cache_inject(const QString &hostname, const QHostInfo &resolution) { QAbstractHostInfoLookupManager* manager = theHostInfoLookupManager(); if (!manager || !manager->cache.isEnabled()) return; manager->cache.put(hostname, resolution); } #endif // cache for 60 seconds // cache 128 items QHostInfoCache::QHostInfoCache() : max_age(60), enabled(true), cache(128) { #ifdef QT_QHOSTINFO_CACHE_DISABLED_BY_DEFAULT enabled = false; #endif } bool QHostInfoCache::isEnabled() { return enabled; } // this function is currently only used for the auto tests // and not usable by public API void QHostInfoCache::setEnabled(bool e) { enabled = e; } QHostInfo QHostInfoCache::get(const QString &name, bool *valid) { QMutexLocker locker(&this->mutex); *valid = false; if (QHostInfoCacheElement *element = cache.object(name)) { if (element->age.elapsed() < max_age*1000) *valid = true; return element->info; // FIXME idea: // if too old but not expired, trigger a new lookup // to freshen our cache } return QHostInfo(); } void QHostInfoCache::put(const QString &name, const QHostInfo &info) { // if the lookup failed, don't cache if (info.error() != QHostInfo::NoError) return; QHostInfoCacheElement* element = new QHostInfoCacheElement(); element->info = info; element->age = QElapsedTimer(); element->age.start(); QMutexLocker locker(&this->mutex); cache.insert(name, element); // cache will take ownership } void QHostInfoCache::clear() { QMutexLocker locker(&this->mutex); cache.clear(); } QAbstractHostInfoLookupManager* QAbstractHostInfoLookupManager::globalInstance() { return theHostInfoLookupManager(); } QT_END_NAMESPACE