src/statusbar/mountpointobservercache.cpp

   1 /*
   2  * SPDX-FileCopyrightText: 2014 Frank Reininghaus <frank78ac@googlemail.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-or-later
   5  */
   6
   7 #include "mountpointobservercache.h"
   8
   9 #include "mountpointobserver.h"
  10
  11 #include <KMountPoint>
  12
  13 #include <QTimer>
  14
  15 class MountPointObserverCacheSingleton
  16 {
  17 public:
  18     MountPointObserverCache instance;
  19 };
  20 Q_GLOBAL_STATIC(MountPointObserverCacheSingleton, s_MountPointObserverCache)
  21
  22 MountPointObserverCache::MountPointObserverCache()
  23     : m_observerForMountPoint()
  24     , m_mountPointForObserver()
  25     , m_updateTimer(nullptr)
  26 {
  27     m_updateTimer = new QTimer(this);
  28 }
  29
  30 MountPointObserverCache::~MountPointObserverCache()
  31 {
  32 }
  33
  34 MountPointObserverCache *MountPointObserverCache::instance()
  35 {
  36     return &s_MountPointObserverCache->instance;
  37 }
  38
  39 MountPointObserver *MountPointObserverCache::observerForUrl(const QUrl &url)
  40 {
  41     QUrl cachedObserverUrl;
  42     // If the url is a local path we can extract the root dir by checking the mount points.
  43     if (url.isLocalFile()) {
  44         // Try to share the observer with other paths that have the same mount point.
  45         KMountPoint::Ptr mountPoint = KMountPoint::currentMountPoints().findByPath(url.toLocalFile());
  46         if (mountPoint) {
  47             cachedObserverUrl = QUrl::fromLocalFile(mountPoint->mountPoint());
  48         } else {
  49             // Even if determining the mount point failed, the observer might still
  50             // be able to retrieve information about the url.
  51             cachedObserverUrl = url;
  52         }
  53     } else {
  54         cachedObserverUrl = url;
  55     }
  56
  57     MountPointObserver *observer = m_observerForMountPoint.value(cachedObserverUrl);
  58     if (!observer) {
  59         observer = new MountPointObserver(cachedObserverUrl, this);
  60         m_observerForMountPoint.insert(cachedObserverUrl, observer);
  61         m_mountPointForObserver.insert(observer, cachedObserverUrl);
  62         Q_ASSERT(m_observerForMountPoint.count() == m_mountPointForObserver.count());
  63
  64         connect(observer, &MountPointObserver::destroyed, this, &MountPointObserverCache::slotObserverDestroyed);
  65
  66         if (!m_updateTimer->isActive()) {
  67             m_updateTimer->start(60000); // 1 minute
  68         }
  69
  70         connect(m_updateTimer, &QTimer::timeout, observer, &MountPointObserver::update);
  71     }
  72
  73     return observer;
  74 }
  75
  76 void MountPointObserverCache::slotObserverDestroyed(QObject *observer)
  77 {
  78     Q_ASSERT(m_mountPointForObserver.contains(observer));
  79     const QUrl &url = m_mountPointForObserver.value(observer);
  80     Q_ASSERT(m_observerForMountPoint.contains(url));
  81     m_observerForMountPoint.remove(url);
  82     m_mountPointForObserver.remove(observer);
  83
  84     Q_ASSERT(m_observerForMountPoint.count() == m_mountPointForObserver.count());
  85
  86     if (m_mountPointForObserver.isEmpty()) {
  87         m_updateTimer->stop();
  88     }
  89 }
  90
  91 #include "moc_mountpointobservercache.cpp"