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/****************************************************************************
**
** Copyright (C) 2019 Luxoft Sweden AB
** Copyright (C) 2018 Pelagicore AG
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QmlLive tool.
**
** $QT_BEGIN_LICENSE:GPL-QTAS$
** Commercial License Usage
** Licensees holding valid commercial Qt Automotive Suite 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 The Qt Company. For
** licensing terms and conditions see https://www.qt.io/terms-conditions.
** For further information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
** SPDX-License-Identifier: GPL-3.0
**
****************************************************************************/
#include "watcher.h"
/*!
\class Watcher
\internal
\brief A class which watches Directories and notifies you about changes
A class which watches Directories and notifies you about every change in this Directory or in it's SubDirectories
*/
/*!
\enum Watcher::Error
\brief Describes error state of a Watcher
\value NoError
No error
\value MaximumReached
The maximum number of watches set with setMaximumWatches() was exceeded
\value SystemError
QFileSystemWatcher::addPath failed for an unspecified reason
*/
int Watcher::s_maximumWatches = -1;
/*!
Default Constructor using parent as parent
*/
Watcher::Watcher(QObject *parent)
: QObject(parent)
, m_watcher(new QFileSystemWatcher(this))
, m_waitTimer(new QTimer(this))
{
connect(m_watcher, &QFileSystemWatcher::directoryChanged, this, &Watcher::recordChange);
connect(m_waitTimer, &QTimer::timeout, this, &Watcher::notifyChanges);
m_waitTimer->setInterval(100);
m_waitTimer->setSingleShot(true);
}
/*!
Set the watching Directory to path.
Every change within this Directory and it's sub Directories will be reported by
the directoriesChanged() signal
*/
void Watcher::setDirectory(const QString &path)
{
m_rootDir = QDir(path);
removeAllPaths();
setError(NoError);
addDirectoriesRecursively(m_rootDir.absolutePath());
}
/*!
Returns the Directory watched for changes
*/
QString Watcher::directory() const
{
return m_rootDir.absolutePath();
}
/*!
\fn Watcher::maximumWatches()
Returns the maximum number of watched directories
*/
/*!
Sets the maximum number of watched directories
This will only take effect with next setDirectory() call.
*/
void Watcher::setMaximumWatches(int maximumWatches)
{
s_maximumWatches = maximumWatches;
}
/*!
\fn Watcher::hasError() const
Returns true if error() is not NoError
*/
/*!
\fn Watcher::error() const
Describes the current error state of this watcher
*/
/*!
\fn Watcher::errorChanged()
Notifies about error() change
*/
/*!
Add path and all it's SubDirectory to the internal used QFileSystemWatcher
*/
void Watcher::addDirectoriesRecursively(const QString &path)
{
// qDebug() << "scan: " << path;
addDirectory(path);
QDirIterator iter(path, QDir::Dirs|QDir::NoDotAndDotDot, QDirIterator::Subdirectories);
while (iter.hasNext() && !hasError()) {
QDir entry(iter.next());
addDirectory(entry.absolutePath());
}
}
void Watcher::addDirectory(const QString &path)
{
if (m_watcher->directories().contains(path))
return;
if (s_maximumWatches > 0 &&
m_watcher->directories().count() + m_watcher->files().count() > s_maximumWatches) {
removeAllPaths();
setError(MaximumReached);
return;
}
m_watcher->addPath(path);
if (!m_watcher->directories().contains(path)) {
removeAllPaths();
setError(SystemError);
}
}
void Watcher::removeAllPaths()
{
if (!m_watcher->directories().isEmpty()) {
m_watcher->removePaths(m_watcher->directories());
}
if (!m_watcher->files().isEmpty()) {
m_watcher->removePaths(m_watcher->files());
}
}
void Watcher::setError(Watcher::Error error)
{
if (m_error == error)
return;
m_error = error;
emit errorChanged();
}
void Watcher::recordChange(const QString &path)
{
// qDebug() << "Watcher::recordChange: " << path;
m_changes.append(path);
m_waitTimer->start();
}
/*!
Filters all the Directory changes.
It tries to minimize the List of changes to the minimal common path.
Example:
Changes:
/home/qmllive/test/images
/home/qmllive/test
/home/user
Will be filtered to:
/home/qmllive/test
/home/user
*/
void Watcher::notifyChanges()
{
// qDebug() << "changes" << m_changes;
// sort to be able to avoid re-scan of recorded sub-folders
QStringList final;
QString top;
// sort changes so top-most dirs stay first
//TODO: wrong assumption, since "aaa<a-umlaut>/" > "aaa/very/deep/hierarchy"
// we need to sort according to the number of sections when split by QDir::Separator
m_changes.sort();
foreach (const QString& entry, m_changes) {
if (!QDir(entry).exists()) {
// dir was removed
if (m_watcher->directories().contains(entry)) {
m_watcher->removePath(entry);
}
} else {
if (top.isNull() || !entry.startsWith(top)) {
top = entry;
final.append(entry);
}
}
}
m_changes.clear();
// need to rescan these top-most dirs
foreach (const QString& entry, final) {
addDirectoriesRecursively(entry);
}
emit directoriesChanged(final);
// qDebug() << "watcher directories: " << m_watcher->directories();
}
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