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Diffstat (limited to 'src/corelib/io/qfilesystemwatcher.cpp')
| -rw-r--r-- | src/corelib/io/qfilesystemwatcher.cpp | 620 |
1 files changed, 620 insertions, 0 deletions
diff --git a/src/corelib/io/qfilesystemwatcher.cpp b/src/corelib/io/qfilesystemwatcher.cpp new file mode 100644 index 0000000..e073a08 --- /dev/null +++ b/src/corelib/io/qfilesystemwatcher.cpp @@ -0,0 +1,620 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (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 qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qfilesystemwatcher.h" +#include "qfilesystemwatcher_p.h" + +#ifndef QT_NO_FILESYSTEMWATCHER + +#include <qdatetime.h> +#include <qdebug.h> +#include <qdir.h> +#include <qfileinfo.h> +#include <qmutex.h> +#include <qset.h> +#include <qtimer.h> + +#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<QString, FileInfo> 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 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<QString> 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<QString> 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<QString, FileInfo> fit(files); + while (fit.hasNext()) { + QHash<QString, FileInfo>::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<QString, FileInfo> dit(directories); + while (dit.hasNext()) { + QHash<QString, FileInfo>::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 + |