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authorMarkus Goetz <Markus.Goetz@nokia.com>2009-12-21 16:03:13 (GMT)
committerMarkus Goetz <Markus.Goetz@nokia.com>2010-03-02 10:15:48 (GMT)
commit5a028f794fe48dc7141acedbf0e896b488bb8cd5 (patch)
tree842a59a33a9e57693f7b537434fb9a04020bc675 /src/network/kernel
parentb08f42e5cc0d94a3b54494f6fe0af90be858f1eb (diff)
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Add DNS caching to QHostInfo
By default enabled, but it can be disabled via a compile flag. Reviewed-by: Thiago
Diffstat (limited to 'src/network/kernel')
-rw-r--r--src/network/kernel/qhostinfo.cpp129
-rw-r--r--src/network/kernel/qhostinfo_p.h32
2 files changed, 154 insertions, 7 deletions
diff --git a/src/network/kernel/qhostinfo.cpp b/src/network/kernel/qhostinfo.cpp
index b23f6db..a65ca50 100644
--- a/src/network/kernel/qhostinfo.cpp
+++ b/src/network/kernel/qhostinfo.cpp
@@ -181,9 +181,26 @@ int QHostInfo::lookupHost(const QString &name, QObject *receiver,
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);
+ 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;
@@ -418,14 +435,12 @@ void QHostInfoRunnable::run()
return;
}
- // check cache
- // FIXME
-
// if not in cache: OS lookup
QHostInfo hostInfo = QHostInfoAgent::fromName(toBeLookedUp);
// save to cache
- // FIXME
+ if (manager->cache.isEnabled())
+ manager->cache.put(toBeLookedUp, hostInfo);
// check aborted again
if (manager->wasAborted(id)) {
@@ -575,6 +590,106 @@ void QHostInfoLookupManager::lookupFinished(QHostInfoRunnable *r)
work();
}
+// This function returns immediatly 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
+ QHostInfoLookupManager* 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()
+{
+ QHostInfoLookupManager* manager = theHostInfoLookupManager();
+ if (manager) {
+ manager->cache.clear();
+ }
+}
+
+void Q_NETWORK_EXPORT qt_qhostinfo_enable_cache(bool e)
+{
+ QHostInfoLookupManager* manager = theHostInfoLookupManager();
+ if (manager) {
+ manager->cache.setEnabled(e);
+ }
+}
+
+// cache for 60 seconds
+// cache 64 items
+QHostInfoCache::QHostInfoCache() : max_age(60), enabled(true), cache(64)
+{
+#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 (cache.contains(name)) {
+ 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 = QTime();
+ element->age.start();
+
+ QMutexLocker locker(&this->mutex);
+ cache.insert(name, element); // cache will take ownership
+}
+
+void QHostInfoCache::clear()
+{
+ QMutexLocker locker(&this->mutex);
+ cache.clear();
+}
+
#endif // QT_NO_THREAD
QT_END_NAMESPACE
diff --git a/src/network/kernel/qhostinfo_p.h b/src/network/kernel/qhostinfo_p.h
index d6aa287..2b26b07 100644
--- a/src/network/kernel/qhostinfo_p.h
+++ b/src/network/kernel/qhostinfo_p.h
@@ -68,6 +68,8 @@
#include "QtCore/qrunnable.h"
#include "QtCore/qlist.h"
#include "QtCore/qqueue.h"
+#include <QTime>
+#include <QCache>
#endif
QT_BEGIN_NAMESPACE
@@ -111,6 +113,34 @@ public:
};
#ifndef QT_NO_THREAD
+// These functions are outside of the QHostInfo class and strictly internal.
+// Do NOT use them outside of QAbstractSocket.
+QHostInfo Q_NETWORK_EXPORT qt_qhostinfo_lookup(const QString &name, QObject *receiver, const char *member, bool *valid, int *id);
+void Q_NETWORK_EXPORT qt_qhostinfo_clear_cache();
+void Q_AUTOTEST_EXPORT qt_qhostinfo_enable_cache(bool e);
+
+class QHostInfoCache
+{
+public:
+ QHostInfoCache();
+ const int max_age; // seconds
+
+ QHostInfo get(const QString &name, bool *valid);
+ void put(const QString &name, const QHostInfo &info);
+ void clear();
+
+ bool isEnabled();
+ void setEnabled(bool e);
+private:
+ bool enabled;
+ struct QHostInfoCacheElement {
+ QHostInfo info;
+ QTime age;
+ };
+ QCache<QString,QHostInfoCacheElement> cache;
+ QMutex mutex;
+};
+
// the following classes are used for the (normal) case: We use multiple threads to lookup DNS
class QHostInfoRunnable : public QRunnable
@@ -141,6 +171,7 @@ public:
void lookupFinished(QHostInfoRunnable *r);
bool wasAborted(int id);
+ QHostInfoCache cache;
protected:
QList<QHostInfoRunnable*> currentLookups; // in progress
QList<QHostInfoRunnable*> postponedLookups; // postponed because in progress for same host
@@ -154,6 +185,7 @@ protected:
bool wasDeleted;
};
+
#endif
QT_END_NAMESPACE