src/statusbar/mountpointobservercache.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2014 by Frank Reininghaus <frank78ac@googlemail.com>    *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program; if not, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA          *
  18  ***************************************************************************/
  19
  20 #include "mountpointobservercache.h"
  21
  22 #include "mountpointobserver.h"
  23
  24 #include <KMountPoint>
  25
  26 #include <QTimer>
  27
  28 class MountPointObserverCacheSingleton
  29 {
  30 public:
  31     MountPointObserverCache instance;
  32 };
  33 Q_GLOBAL_STATIC(MountPointObserverCacheSingleton, s_MountPointObserverCache)
  34
  35
  36 MountPointObserverCache::MountPointObserverCache() :
  37     m_observerForMountPoint(),
  38     m_mountPointForObserver(),
  39     m_updateTimer(nullptr)
  40 {
  41     m_updateTimer = new QTimer(this);
  42 }
  43
  44 MountPointObserverCache::~MountPointObserverCache()
  45 {
  46 }
  47
  48 MountPointObserverCache* MountPointObserverCache::instance()
  49 {
  50     return &s_MountPointObserverCache->instance;
  51 }
  52
  53 MountPointObserver* MountPointObserverCache::observerForUrl(const QUrl& url)
  54 {
  55     QUrl cachedObserverUrl;
  56     // If the url is a local path we can extract the root dir by checking the mount points.
  57     if (url.isLocalFile()) {
  58         // Try to share the observer with other paths that have the same mount point.
  59         KMountPoint::Ptr mountPoint = KMountPoint::currentMountPoints().findByPath(url.toLocalFile());
  60         if (mountPoint) {
  61             cachedObserverUrl = QUrl::fromLocalFile(mountPoint->mountPoint());
  62         } else {
  63             // Even if determining the mount point failed, the observer might still
  64             // be able to retrieve information about the url.
  65             cachedObserverUrl = url;
  66         }
  67     } else {
  68         cachedObserverUrl = url;
  69     }
  70
  71     MountPointObserver* observer = m_observerForMountPoint.value(cachedObserverUrl);
  72     if (!observer) {
  73         observer = new MountPointObserver(cachedObserverUrl, this);
  74         m_observerForMountPoint.insert(cachedObserverUrl, observer);
  75         m_mountPointForObserver.insert(observer, cachedObserverUrl);
  76         Q_ASSERT(m_observerForMountPoint.count() == m_mountPointForObserver.count());
  77
  78         connect(observer, &MountPointObserver::destroyed, this, &MountPointObserverCache::slotObserverDestroyed);
  79
  80         if (!m_updateTimer->isActive()) {
  81             m_updateTimer->start(60000); // 1 minute
  82         }
  83
  84         connect(m_updateTimer, &QTimer::timeout, observer, &MountPointObserver::update);
  85     }
  86
  87     return observer;
  88 }
  89
  90 void MountPointObserverCache::slotObserverDestroyed(QObject* observer)
  91 {
  92     Q_ASSERT(m_mountPointForObserver.contains(observer));
  93     const QUrl& url = m_mountPointForObserver.value(observer);
  94     Q_ASSERT(m_observerForMountPoint.contains(url));
  95     m_observerForMountPoint.remove(url);
  96     m_mountPointForObserver.remove(observer);
  97
  98     Q_ASSERT(m_observerForMountPoint.count() == m_mountPointForObserver.count());
  99
 100     if (m_mountPointForObserver.isEmpty()) {
 101         m_updateTimer->stop();
 102     }
 103 }