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 <KGlobal>
  25 #include <KMountPoint>
  26
  27 #include <QTimer>
  28
  29 class MountPointObserverCacheSingleton
  30 {
  31 public:
  32     MountPointObserverCache instance;
  33 };
  34 K_GLOBAL_STATIC(MountPointObserverCacheSingleton, s_MountPointObserverCache)
  35
  36
  37 MountPointObserverCache::MountPointObserverCache() :
  38     m_observerForMountPoint(),
  39     m_mountPointForObserver(),
  40     m_updateTimer(0)
  41 {
  42     m_updateTimer = new QTimer(this);
  43 }
  44
  45 MountPointObserverCache::~MountPointObserverCache()
  46 {
  47 }
  48
  49 MountPointObserverCache* MountPointObserverCache::instance()
  50 {
  51     return &s_MountPointObserverCache->instance;
  52 }
  53
  54 MountPointObserver* MountPointObserverCache::observerForUrl(const QUrl& url)
  55 {
  56     QUrl cachedObserverUrl;
  57     // If the url is a local path we can extract the root dir by checking the mount points.
  58     if (url.isLocalFile()) {
  59         // Try to share the observer with other paths that have the same mount point.
  60         KMountPoint::Ptr mountPoint = KMountPoint::currentMountPoints().findByPath(url.toLocalFile());
  61         if (mountPoint) {
  62             cachedObserverUrl = QUrl::fromLocalFile(mountPoint->mountPoint());
  63         } else {
  64             // Even if determining the mount point failed, the observer might still
  65             // be able to retrieve information about the url.
  66             cachedObserverUrl = url.toLocalFile();
  67         }
  68     } else {
  69         cachedObserverUrl = url.url();
  70     }
  71
  72     MountPointObserver* observer = m_observerForMountPoint.value(cachedObserverUrl);
  73     if (!observer) {
  74         observer = new MountPointObserver(cachedObserverUrl, this);
  75         m_observerForMountPoint.insert(cachedObserverUrl, observer);
  76         m_mountPointForObserver.insert(observer, cachedObserverUrl);
  77         Q_ASSERT(m_observerForMountPoint.count() == m_mountPointForObserver.count());
  78
  79         connect(observer, &MountPointObserver::destroyed, this, &MountPointObserverCache::slotObserverDestroyed);
  80
  81         if (!m_updateTimer->isActive()) {
  82             m_updateTimer->start(10000);
  83         }
  84
  85         connect(m_updateTimer, &QTimer::timeout, observer, &MountPointObserver::update);
  86     }
  87
  88     return observer;
  89 }
  90
  91 void MountPointObserverCache::slotObserverDestroyed(QObject* observer)
  92 {
  93     Q_ASSERT(m_mountPointForObserver.contains(observer));
  94     const QUrl& url = m_mountPointForObserver.value(observer);
  95     Q_ASSERT(m_observerForMountPoint.contains(url));
  96     m_observerForMountPoint.remove(url);
  97     m_mountPointForObserver.remove(observer);
  98
  99     Q_ASSERT(m_observerForMountPoint.count() == m_mountPointForObserver.count());
 100
 101     if (m_mountPointForObserver.isEmpty()) {
 102         m_updateTimer->stop();
 103     }
 104 }