/**************************************************************************** ** ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the QtCore module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** No Commercial Usage ** This file contains pre-release code and may not be distributed. ** You may use this file in accordance with the terms and conditions ** contained in the either Technology Preview License Agreement or the ** Beta Release License Agreement. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 2.1 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 2.1 requirements ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain ** additional rights. These rights are described in the Nokia Qt LGPL ** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this ** package. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3.0 as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** If you are unsure which license is appropriate for your use, please ** contact the sales department at http://www.qtsoftware.com/contact. ** $QT_END_LICENSE$ ** ****************************************************************************/ #include "qfilesystemwatcher.h" #include "qfilesystemwatcher_p.h" #ifndef QT_NO_FILESYSTEMWATCHER #include #include #include #include #include #include #include #if defined(Q_OS_WIN) # include "qfilesystemwatcher_win_p.h" #elif defined(Q_OS_LINUX) # include "qfilesystemwatcher_inotify_p.h" # include "qfilesystemwatcher_dnotify_p.h" #elif defined(Q_OS_FREEBSD) || defined(Q_OS_MAC) # include "qfilesystemwatcher_kqueue_p.h" #endif QT_BEGIN_NAMESPACE enum { PollingInterval = 1000 }; class QPollingFileSystemWatcherEngine : public QFileSystemWatcherEngine { Q_OBJECT class FileInfo { uint ownerId; uint groupId; QFile::Permissions permissions; QDateTime lastModified; QStringList entries; public: FileInfo(const QFileInfo &fileInfo) : ownerId(fileInfo.ownerId()), groupId(fileInfo.groupId()), permissions(fileInfo.permissions()), lastModified(fileInfo.lastModified()) { if (fileInfo.isDir()) { entries = fileInfo.absoluteDir().entryList(QDir::AllEntries); } } FileInfo &operator=(const QFileInfo &fileInfo) { *this = FileInfo(fileInfo); return *this; } bool operator!=(const QFileInfo &fileInfo) const { if (fileInfo.isDir() && entries != fileInfo.absoluteDir().entryList(QDir::AllEntries)) return true; return (ownerId != fileInfo.ownerId() || groupId != fileInfo.groupId() || permissions != fileInfo.permissions() || lastModified != fileInfo.lastModified()); } }; mutable QMutex mutex; QHash files, directories; public: QPollingFileSystemWatcherEngine(); void run(); QStringList addPaths(const QStringList &paths, QStringList *files, QStringList *directories); QStringList removePaths(const QStringList &paths, QStringList *files, QStringList *directories); void stop(); private Q_SLOTS: void timeout(); }; QPollingFileSystemWatcherEngine::QPollingFileSystemWatcherEngine() { #ifndef QT_NO_THREAD moveToThread(this); #endif } void QPollingFileSystemWatcherEngine::run() { QTimer timer; connect(&timer, SIGNAL(timeout()), SLOT(timeout())); timer.start(PollingInterval); (void) exec(); } QStringList QPollingFileSystemWatcherEngine::addPaths(const QStringList &paths, QStringList *files, QStringList *directories) { QMutexLocker locker(&mutex); QStringList p = paths; QMutableListIterator it(p); while (it.hasNext()) { QString path = it.next(); QFileInfo fi(path); if (!fi.exists()) continue; if (fi.isDir()) { if (!directories->contains(path)) directories->append(path); if (!path.endsWith(QLatin1Char('/'))) fi = QFileInfo(path + QLatin1Char('/')); this->directories.insert(path, fi); } else { if (!files->contains(path)) files->append(path); this->files.insert(path, fi); } it.remove(); } start(); return p; } QStringList QPollingFileSystemWatcherEngine::removePaths(const QStringList &paths, QStringList *files, QStringList *directories) { QMutexLocker locker(&mutex); QStringList p = paths; QMutableListIterator it(p); while (it.hasNext()) { QString path = it.next(); if (this->directories.remove(path)) { directories->removeAll(path); it.remove(); } else if (this->files.remove(path)) { files->removeAll(path); it.remove(); } } if (this->files.isEmpty() && this->directories.isEmpty()) { locker.unlock(); stop(); wait(); } return p; } void QPollingFileSystemWatcherEngine::stop() { QMetaObject::invokeMethod(this, "quit"); } void QPollingFileSystemWatcherEngine::timeout() { QMutexLocker locker(&mutex); QMutableHashIterator fit(files); while (fit.hasNext()) { QHash::iterator x = fit.next(); QString path = x.key(); QFileInfo fi(path); if (!fi.exists()) { fit.remove(); emit fileChanged(path, true); } else if (x.value() != fi) { x.value() = fi; emit fileChanged(path, false); } } QMutableHashIterator dit(directories); while (dit.hasNext()) { QHash::iterator x = dit.next(); QString path = x.key(); QFileInfo fi(path); if (!path.endsWith(QLatin1Char('/'))) fi = QFileInfo(path + QLatin1Char('/')); if (!fi.exists()) { dit.remove(); emit directoryChanged(path, true); } else if (x.value() != fi) { x.value() = fi; emit directoryChanged(path, false); } } } QFileSystemWatcherEngine *QFileSystemWatcherPrivate::createNativeEngine() { #if defined(Q_OS_WIN) return new QWindowsFileSystemWatcherEngine; #elif defined(Q_OS_LINUX) QFileSystemWatcherEngine *eng = QInotifyFileSystemWatcherEngine::create(); if(!eng) eng = QDnotifyFileSystemWatcherEngine::create(); return eng; #elif defined(Q_OS_FREEBSD) || defined(Q_OS_MAC) return QKqueueFileSystemWatcherEngine::create(); #else return 0; #endif } QFileSystemWatcherPrivate::QFileSystemWatcherPrivate() : native(0), poller(0), forced(0) { } void QFileSystemWatcherPrivate::init() { Q_Q(QFileSystemWatcher); native = createNativeEngine(); if (native) { QObject::connect(native, SIGNAL(fileChanged(QString,bool)), q, SLOT(_q_fileChanged(QString,bool))); QObject::connect(native, SIGNAL(directoryChanged(QString,bool)), q, SLOT(_q_directoryChanged(QString,bool))); } } void QFileSystemWatcherPrivate::initForcedEngine(const QString &forceName) { if(forced) return; Q_Q(QFileSystemWatcher); #if defined(Q_OS_LINUX) if(forceName == QLatin1String("inotify")) { forced = QInotifyFileSystemWatcherEngine::create(); } else if(forceName == QLatin1String("dnotify")) { forced = QDnotifyFileSystemWatcherEngine::create(); } #else Q_UNUSED(forceName); #endif if(forced) { QObject::connect(forced, SIGNAL(fileChanged(QString,bool)), q, SLOT(_q_fileChanged(QString,bool))); QObject::connect(forced, SIGNAL(directoryChanged(QString,bool)), q, SLOT(_q_directoryChanged(QString,bool))); } } void QFileSystemWatcherPrivate::initPollerEngine() { if(poller) return; Q_Q(QFileSystemWatcher); poller = new QPollingFileSystemWatcherEngine; // that was a mouthful QObject::connect(poller, SIGNAL(fileChanged(QString,bool)), q, SLOT(_q_fileChanged(QString,bool))); QObject::connect(poller, SIGNAL(directoryChanged(QString,bool)), q, SLOT(_q_directoryChanged(QString,bool))); } void QFileSystemWatcherPrivate::_q_fileChanged(const QString &path, bool removed) { Q_Q(QFileSystemWatcher); if (!files.contains(path)) { // the path was removed after a change was detected, but before we delivered the signal return; } if (removed) files.removeAll(path); emit q->fileChanged(path); } void QFileSystemWatcherPrivate::_q_directoryChanged(const QString &path, bool removed) { Q_Q(QFileSystemWatcher); if (!directories.contains(path)) { // perhaps the path was removed after a change was detected, but before we delivered the signal return; } if (removed) directories.removeAll(path); emit q->directoryChanged(path); } /*! \class QFileSystemWatcher \brief The QFileSystemWatcher class provides an interface for monitoring files and directories for modifications. \ingroup io \since 4.2 \reentrant QFileSystemWatcher monitors the file system for changes to files and directories by watching a list of specified paths. Call addPath() to watch a particular file or directory. Multiple paths can be added using the addPaths() function. Existing paths can be removed by using the removePath() and removePaths() functions. QFileSystemWatcher examines each path added to it. Files that have been added to the QFileSystemWatcher can be accessed using the files() function, and directories using the directories() function. The fileChanged() signal is emitted when a file has been modified, renamed or removed from disk. Similarly, the directoryChanged() signal is emitted when a directory or its contents is modified or removed. Note that QFileSystemWatcher stops monitoring files once they have been renamed or removed from disk, and directories once they have been removed from disk. \note On systems running a Linux kernel without inotify support, file systems that contain watched paths cannot be unmounted. \note Windows CE does not support directory monitoring by default as this depends on the file system driver installed. \note The act of monitoring files and directories for modifications consumes system resources. This implies there is a limit to the number of files and directories your process can monitor simultaneously. On Mac OS and all BSD variants, for example, an open file descriptor is required for each monitored file. The system limits the number of open file descriptors to 256 by default. This means that addPath() and addPaths() will fail if your process tries to add more than 256 files or directories to the file system monitor. Also note that your process may have other file descriptors open in addition to the ones for files being monitored, and these other open descriptors also count in the total. \sa QFile, QDir */ /*! Constructs a new file system watcher object with the given \a parent. */ QFileSystemWatcher::QFileSystemWatcher(QObject *parent) : QObject(*new QFileSystemWatcherPrivate, parent) { d_func()->init(); } /*! Constructs a new file system watcher object with the given \a parent which monitors the specified \a paths list. */ QFileSystemWatcher::QFileSystemWatcher(const QStringList &paths, QObject *parent) : QObject(*new QFileSystemWatcherPrivate, parent) { d_func()->init(); addPaths(paths); } /*! Destroys the file system watcher. */ QFileSystemWatcher::~QFileSystemWatcher() { Q_D(QFileSystemWatcher); if (d->native) { d->native->stop(); d->native->wait(); delete d->native; d->native = 0; } if (d->poller) { d->poller->stop(); d->poller->wait(); delete d->poller; d->poller = 0; } if (d->forced) { d->forced->stop(); d->forced->wait(); delete d->forced; d->forced = 0; } } /*! Adds \a path to the file system watcher if \a path exists. The path is not added if it does not exist, or if it is already being monitored by the file system watcher. If \a path specifies a directory, the directoryChanged() signal will be emitted when \a path is modified or removed from disk; otherwise the fileChanged() signal is emitted when \a path is modified, renamed or removed. \note There is a system dependent limit to the number of files and directories that can be monitored simultaneously. If this limit has been reached, \a path will not be added to the file system watcher, and a warning message will be printed to \e{stderr}. \sa addPaths(), removePath() */ void QFileSystemWatcher::addPath(const QString &path) { if (path.isEmpty()) { qWarning("QFileSystemWatcher::addPath: path is empty"); return; } addPaths(QStringList(path)); } /*! Adds each path in \a paths to the file system watcher. Paths are not added if they not exist, or if they are already being monitored by the file system watcher. If a path specifies a directory, the directoryChanged() signal will be emitted when the path is modified or removed from disk; otherwise the fileChanged() signal is emitted when the path is modified, renamed, or removed. \note There is a system dependent limit to the number of files and directories that can be monitored simultaneously. If this limit has been reached, the excess \a paths will not be added to the file system watcher, and a warning message will be printed to \e{stderr} for each path that could not be added. \sa addPath(), removePaths() */ void QFileSystemWatcher::addPaths(const QStringList &paths) { Q_D(QFileSystemWatcher); if (paths.isEmpty()) { qWarning("QFileSystemWatcher::addPaths: list is empty"); return; } QStringList p = paths; QFileSystemWatcherEngine *engine = 0; if(!objectName().startsWith(QLatin1String("_qt_autotest_force_engine_"))) { // Normal runtime case - search intelligently for best engine if(d->native) { engine = d->native; } else { d_func()->initPollerEngine(); engine = d->poller; } } else { // Autotest override case - use the explicitly selected engine only QString forceName = objectName().mid(26); if(forceName == QLatin1String("poller")) { qDebug() << "QFileSystemWatcher: skipping native engine, using only polling engine"; d_func()->initPollerEngine(); engine = d->poller; } else if(forceName == QLatin1String("native")) { qDebug() << "QFileSystemWatcher: skipping polling engine, using only native engine"; engine = d->native; } else { qDebug() << "QFileSystemWatcher: skipping polling and native engine, using only explicit" << forceName << "engine"; d_func()->initForcedEngine(forceName); engine = d->forced; } } if(engine) p = engine->addPaths(p, &d->files, &d->directories); if (!p.isEmpty()) qWarning("QFileSystemWatcher: failed to add paths: %s", qPrintable(p.join(QLatin1String(", ")))); } /*! Removes the specified \a path from the file system watcher. \sa removePaths(), addPath() */ void QFileSystemWatcher::removePath(const QString &path) { if (path.isEmpty()) { qWarning("QFileSystemWatcher::removePath: path is empty"); return; } removePaths(QStringList(path)); } /*! Removes the specified \a paths from the file system watcher. \sa removePath(), addPaths() */ void QFileSystemWatcher::removePaths(const QStringList &paths) { if (paths.isEmpty()) { qWarning("QFileSystemWatcher::removePaths: list is empty"); return; } Q_D(QFileSystemWatcher); QStringList p = paths; if (d->native) p = d->native->removePaths(p, &d->files, &d->directories); if (d->poller) p = d->poller->removePaths(p, &d->files, &d->directories); if (d->forced) p = d->forced->removePaths(p, &d->files, &d->directories); } /*! \fn void QFileSystemWatcher::fileChanged(const QString &path) This signal is emitted when the file at the specified \a path is modified, renamed or removed from disk. \sa directoryChanged() */ /*! \fn void QFileSystemWatcher::directoryChanged(const QString &path) This signal is emitted when the directory at a specified \a path, is modified (e.g., when a file is added, modified or deleted) or removed from disk. Note that if there are several changes during a short period of time, some of the changes might not emit this signal. However, the last change in the sequence of changes will always generate this signal. \sa fileChanged() */ /*! \fn QStringList QFileSystemWatcher::directories() const Returns a list of paths to directories that are being watched. \sa files() */ /*! \fn QStringList QFileSystemWatcher::files() const Returns a list of paths to files that are being watched. \sa directories() */ QStringList QFileSystemWatcher::directories() const { Q_D(const QFileSystemWatcher); return d->directories; } QStringList QFileSystemWatcher::files() const { Q_D(const QFileSystemWatcher); return d->files; } QT_END_NAMESPACE #include "moc_qfilesystemwatcher.cpp" #include "qfilesystemwatcher.moc" #endif // QT_NO_FILESYSTEMWATCHER