Mac: FSEvents-based QFileSystemWatcherEngine.

Use FSEvents to monitor changes in the filesystem instead of the kqueue
implementation. This removes the limit of wathed files: kqueue uses a
file descriptor for each file monitored, for which the ulimit was set by
default to 256. Now the OSX implementation on par with the other major
desktop platforms.

Change-Id: I2d46cca811978621989fd35201138df88a37c0fb
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

1 files changed, 142 insertions, 0 deletions

diff --git a/src/corelib/io/qfilesystemwatcher_fsevents_p.h b/src/corelib/io/qfilesystemwatcher_fsevents_p.h
new file mode 100644
index 0000000000..c899c556c8
--- /dev/null
+++ b/src/corelib/io/qfilesystemwatcher_fsevents_p.h
@@ -0,0 +1,142 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QFILESYSTEMWATCHER_FSEVENTS_P_H
+#define QFILESYSTEMWATCHER_FSEVENTS_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of the QLibrary class.  This header file may change from
+// version to version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qfilesystemwatcher_p.h"
+
+#include <QtCore/qmutex.h>
+#include <QtCore/qhash.h>
+#include <QtCore/qthread.h>
+#include <QtCore/qvector.h>
+#include <QtCore/qsocketnotifier.h>
+
+#include <dispatch/dispatch.h>
+#include <CoreServices/CoreServices.h>
+
+#ifndef QT_NO_FILESYSTEMWATCHER
+
+QT_BEGIN_NAMESPACE
+
+class QFseventsFileSystemWatcherEngine : public QFileSystemWatcherEngine
+{
+    Q_OBJECT
+public:
+    ~QFseventsFileSystemWatcherEngine();
+
+    static QFseventsFileSystemWatcherEngine *create(QObject *parent);
+
+    QStringList addPaths(const QStringList &paths, QStringList *files, QStringList *directories);
+    QStringList removePaths(const QStringList &paths, QStringList *files, QStringList *directories);
+
+    void processEvent(ConstFSEventStreamRef streamRef, size_t numEvents, char **eventPaths, const FSEventStreamEventFlags eventFlags[], const FSEventStreamEventId eventIds[]);
+
+Q_SIGNALS:
+    void emitFileChanged(const QString path, bool removed);
+    void emitDirectoryChanged(const QString path, bool removed);
+
+private slots:
+    void doEmitFileChanged(const QString path, bool removed);
+    void doEmitDirectoryChanged(const QString path, bool removed);
+
+private:
+    struct Info {
+        QString origPath;
+        timespec ctime;
+        mode_t mode;
+        QString watchedPath;
+
+        Info(): mode(0)
+        {
+            ctime.tv_sec = 0;
+            ctime.tv_nsec = 0;
+        }
+
+        Info(const QString &origPath, const timespec &ctime, mode_t mode, const QString &watchedPath)
+            : origPath(origPath)
+            , ctime(ctime)
+            , mode(mode)
+            , watchedPath(watchedPath)
+        {}
+    };
+    typedef QHash<QString, Info> InfoByName;
+    typedef QHash<QString, InfoByName> FilesByPath;
+    struct DirInfo {
+        Info dirInfo;
+        InfoByName entries;
+    };
+    typedef QHash<QString, DirInfo> DirsByName;
+    typedef QHash<QString, qint64> PathRefCounts;
+
+    QFseventsFileSystemWatcherEngine(QObject *parent);
+    bool startStream();
+    void stopStream(bool isStopped = false);
+    InfoByName scanForDirEntries(const QString &path);
+    void derefPath(const QString &watchedPath);
+    void checkDir(DirsByName::iterator &it);
+    void rescanDirs(const QString &path);
+    void rescanFiles(InfoByName &filesInPath);
+    void rescanFiles(const QString &path);
+
+    QMutex lock;
+    dispatch_queue_t queue;
+    FSEventStreamRef stream;
+    FilesByPath watchedFiles;
+    DirsByName watchedDirectories;
+    PathRefCounts watchedPaths;
+};
+
+QT_END_NAMESPACE
+
+#endif //QT_NO_FILESYSTEMWATCHER
+#endif // QFILESYSTEMWATCHER_FSEVENTS_P_H