/*!
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 doc/src/snippets/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 doc/src/snippets/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 doc/src/snippets/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<QHostInfo>("QHostInfo");
int id = theIdCounter.fetchAndAddRelaxed(1); // generate unique ID
if (name.isEmpty()) {
QHostInfo hostInfo(id);
hostInfo.setError(QHostInfo::HostNotFound);
hostInfo.setErrorString(QCoreApplication::translate("QHostInfo", "No host name given"));
QScopedPointer<QHostInfoResult> result(new QHostInfoResult);
QObject::connect(result.data(), SIGNAL(resultsReady(QHostInfo)),
receiver, member, Qt::QueuedConnection);
result.data()->emitResultsReady(hostInfo);
return id;
}
#ifdef QT_NO_THREAD
QHostInfo hostInfo = QHostInfoAgent::fromName(name);
hostInfo.setLookupId(id);
QScopedPointer<QHostInfoResult> result(new QHostInfoResult);
QObject::connect(result.data(), SIGNAL(resultsReady(QHostInfo)),
receiver, member, Qt::QueuedConnection);
result.data()->emitResultsReady(hostInfo);
#else
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) {
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);
QObject::connect(&runnable->resultEmitter, SIGNAL(resultsReady(QHostInfo)), receiver, member, Qt::QueuedConnection);
manager->scheduleLookup(runnable);
}
#endif
return id;
}
// 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);
// now also iterate through the postponed ones
{
QMutexLocker locker(&manager->mutex);
QMutableListIterator<QHostInfoRunnable*> iterator(manager->postponedLookups);
while (iterator.hasNext()) {
QHostInfoRunnable* postponed = iterator.next();
if (toBeLookedUp == postponed->toBeLookedUp) {
// we can now emit
iterator.remove();
hostInfo.setLookupId(postponed->id);
postponed->resultEmitter.emitResultsReady(hostInfo);
delete postponed;
}
}
}
manager->lookupFinished(this);
// thread goes back to QThreadPool
}
// 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;
}
// check cache
// FIXME
// if not in cache: OS lookup
QHostInfo hostInfo = QHostInfoAgent::fromName(toBeLookedUp);
// save to cache
// FIXME
// check aborted again
if (manager->wasAborted(id)) {
manager->lookupFinished(this);
return;
}
// signal emission
hostInfo.setLookupId(id);
resultEmitter.emitResultsReady(hostInfo);
manager->lookupFinished(this);
// thread goes back to QThreadPool
}
/*!
\internal
Pops a query off the queries list, performs a blocking call to
QHostInfoAgent::lookupHost(), and emits the resultsReady()
signal. This process repeats until the queries list is empty.
*/
void QHostInfoAgent::run()
{
#ifndef QT_NO_THREAD
// Dont' allow thread termination during event delivery, but allow it
// during the actual blocking host lookup stage.
setTerminationEnabled(false);
forever
#endif
{
QHostInfoQuery *query;
{
#ifndef QT_NO_THREAD
// the queries list is shared between threads. lock all
// access to it.
QMutexLocker locker(&mutex);
if (!quit && queries.isEmpty())
cond.wait(&mutex);
if (quit) {
// Reset the quit variable in case QCoreApplication is
// destroyed and recreated.
quit = false;
break;
}
if (queries.isEmpty())
continue;
#else
if (queries.isEmpty())
return;
#endif
query = queries.takeFirst();
pendingQueryId = query->object->lookupId;
}
#if defined(QHOSTINFO_DEBUG)
qDebug("QHostInfoAgent::run(%p): looking up \"%s\"", this,
query->hostName.toLatin1().constData());
#endif
#ifndef QT_NO_THREAD
// Start query - allow termination at this point, but not outside. We
// don't want to all termination during event delivery, but we don't
// want the lookup to prevent the app from quitting (the agent
// destructor terminates the thread).
setTerminationEnabled(true);
#endif
QHostInfo info = fromName(query->hostName);
#ifndef QT_NO_THREAD
setTerminationEnabled(false);
#endif
int id = query->object->lookupId;
info.setLookupId(id);
if (pendingQueryId == id)
query->object->emitResultsReady(info);
delete query;
}
}
/*!
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 doc/src/snippets/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 doc/src/snippets/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 doc/src/snippets/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<QHostInfo>("QHostInfo");
int id = theIdCounter.fetchAndAddRelaxed(1); // generate unique ID
if (name.isEmpty()) {
QHostInfo hostInfo(id);
hostInfo.setError(QHostInfo::HostNotFound);
hostInfo.setErrorString(QObject::tr("No host name given"));
QScopedPointer<QHostInfoResult> result(new QHostInfoResult);
QObject::connect(result.data(), SIGNAL(resultsReady(QHostInfo)),
receiver, member, Qt::QueuedConnection);
result.data()->emitResultsReady(hostInfo);
return id;
}
#ifdef QT_NO_THREAD
QHostInfo hostInfo = QHostInfoAgent::fromName(name);
hostInfo.setLookupId(id);
QScopedPointer<QHostInfoResult> result(new QHostInfoResult);
QObject::connect(result.data(), SIGNAL(resultsReady(QHostInfo)),
receiver, member, Qt::QueuedConnection);
result.data()->emitResultsReady(hostInfo);
#else
QHostInfoRunnable* runnable = new QHostInfoRunnable(name, id);
QObject::connect(&runnable->resultEmitter, SIGNAL(resultsReady(QHostInfo)), receiver, member, Qt::QueuedConnection);
theHostInfoLookupManager()->scheduleLookup(runnable);
#endif
return id;
}
void QHostInfoProto::setLookupId(int id)
{
QHostInfo *item = qscriptvalue_cast<QHostInfo*>(thisObject());
if (item)
item->setLookupId(id);
}
