summaryrefslogtreecommitdiffstats
path: root/src/corelib/io/qfilesystemwatcher.cpp
blob: d9b994e1dd40fe48a6d5a39c4f1c90d2f1f781b7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** 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 Technology Preview License Agreement accompanying
** this package.
**
** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@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)
#  if (defined Q_OS_MAC) && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
#  include "qfilesystemwatcher_fsevents_p.h"
#  endif //MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
#  include "qfilesystemwatcher_kqueue_p.h"
#elif defined(Q_OS_SYMBIAN)
#  include "qfilesystemwatcher_symbian_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 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<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)
#  if 0 && (defined Q_OS_MAC) && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
    if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_5)
        return QFSEventsFileSystemWatcherEngine::create();
    else
#  endif
        return QKqueueFileSystemWatcherEngine::create();
#elif defined(Q_OS_SYMBIAN)
    return new QSymbianFileSystemWatcherEngine;
#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 X 10.4 and all BSD variants, for
    example, an open file descriptor is required for each monitored
    file. Some 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. Mac OS X 10.5 and up use a different backend and do not
    suffer from this issue.


    \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