From 5a028f794fe48dc7141acedbf0e896b488bb8cd5 Mon Sep 17 00:00:00 2001 From: Markus Goetz Date: Mon, 21 Dec 2009 17:03:13 +0100 Subject: Add DNS caching to QHostInfo By default enabled, but it can be disabled via a compile flag. Reviewed-by: Thiago --- src/network/kernel/qhostinfo.cpp | 129 +++++++++++++++++++++++++++++++-- src/network/kernel/qhostinfo_p.h | 32 ++++++++ tests/auto/qhostinfo/tst_qhostinfo.cpp | 55 +++++++++++++- 3 files changed, 208 insertions(+), 8 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 +#include #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 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 currentLookups; // in progress QList postponedLookups; // postponed because in progress for same host @@ -154,6 +185,7 @@ protected: bool wasDeleted; }; + #endif QT_END_NAMESPACE diff --git a/tests/auto/qhostinfo/tst_qhostinfo.cpp b/tests/auto/qhostinfo/tst_qhostinfo.cpp index d5411d0..cbadcf5 100644 --- a/tests/auto/qhostinfo/tst_qhostinfo.cpp +++ b/tests/auto/qhostinfo/tst_qhostinfo.cpp @@ -72,6 +72,7 @@ #endif #include +#include "private/qhostinfo_p.h" #if !defined(QT_NO_GETADDRINFO) # if !defined(Q_OS_WINCE) @@ -108,10 +109,11 @@ public: public slots: void init(); void cleanup(); + void initTestCase(); + private slots: void getSetCheck(); void staticInformation(); - void initTestCase(); void lookupIPv4_data(); void lookupIPv4(); void lookupIPv6_data(); @@ -128,6 +130,8 @@ private slots: void multipleSameLookups(); void multipleDifferentLookups(); + void cache(); + protected slots: void resultsReady(const QHostInfo &); @@ -205,10 +209,21 @@ void tst_QHostInfo::initTestCase() // We have IPv6 support ipv6Available = true; } + + + // run each testcase with and without test enabled + QTest::addColumn("cache"); + QTest::newRow("WithCache") << false; + QTest::newRow("WithoutCache") << true; } void tst_QHostInfo::init() { + // delete the cache so inidividual testcase results are independant from each other + qt_qhostinfo_clear_cache(); + + QFETCH_GLOBAL(bool, cache); + qt_qhostinfo_enable_cache(cache); } void tst_QHostInfo::cleanup() @@ -458,6 +473,44 @@ void tst_QHostInfo::multipleDifferentLookups() QTRY_VERIFY(lookupsDoneCounter == COUNT); } +void tst_QHostInfo::cache() +{ + QFETCH_GLOBAL(bool, cache); + if (!cache) + return; // test makes only sense when cache enabled + + // reset slot counter + lookupsDoneCounter = 0; + + // lookup once, wait in event loop, result should not come directly. + bool valid = true; + QHostInfo result = qt_qhostinfo_lookup("localhost", this, SLOT(resultsReady(QHostInfo)), &valid); + QTestEventLoop::instance().enterLoop(5); + QVERIFY(!QTestEventLoop::instance().timeout()); + QVERIFY(valid == false); + QVERIFY(result.addresses().isEmpty()); + + // loopkup second time, result should come directly + valid = false; + result = qt_qhostinfo_lookup("localhost", this, SLOT(resultsReady(QHostInfo)), &valid); + QVERIFY(valid == true); + QVERIFY(!result.addresses().isEmpty()); + + // clear the cache + qt_qhostinfo_clear_cache(); + + // lookup third time, result should not come directly. + valid = true; + result = qt_qhostinfo_lookup("localhost", this, SLOT(resultsReady(QHostInfo)), &valid); + QTestEventLoop::instance().enterLoop(5); + QVERIFY(!QTestEventLoop::instance().timeout()); + QVERIFY(valid == false); + QVERIFY(result.addresses().isEmpty()); + + // the slot should have been called 2 times. + QVERIFY(lookupsDoneCounter == 2); +} + void tst_QHostInfo::resultsReady(const QHostInfo &hi) { lookupDone = true; -- cgit v0.12