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
  23 MountPointObserverCache::MountPointObserverCache() :
  24     m_observerForMountPoint(),
  25     m_mountPointForObserver(),
  26     m_updateTimer(nullptr)
  27 {
  28     m_updateTimer = new QTimer(this);
  29 }
  30
  31 MountPointObserverCache::~MountPointObserverCache()
  32 {
  33 }
  34
  35 MountPointObserverCache* MountPointObserverCache::instance()
  36 {
  37     return &s_MountPointObserverCache->instance;
  38 }
  39
  40 MountPointObserver* MountPointObserverCache::observerForUrl(const QUrl& url)
  41 {
  42     QUrl cachedObserverUrl;
  43     // If the url is a local path we can extract the root dir by checking the mount points.
  44     if (url.isLocalFile()) {
  45         // Try to share the observer with other paths that have the same mount point.
  46         KMountPoint::Ptr mountPoint = KMountPoint::currentMountPoints().findByPath(url.toLocalFile());
  47         if (mountPoint) {
  48             cachedObserverUrl = QUrl::fromLocalFile(mountPoint->mountPoint());
  49         } else {
  50             // Even if determining the mount point failed, the observer might still
  51             // be able to retrieve information about the url.
  52             cachedObserverUrl = url;
  53         }
  54     } else {
  55         cachedObserverUrl = url;
  56     }
  57
  58     MountPointObserver* observer = m_observerForMountPoint.value(cachedObserverUrl);
  59     if (!observer) {
  60         observer = new MountPointObserver(cachedObserverUrl, this);
  61         m_observerForMountPoint.insert(cachedObserverUrl, observer);
  62         m_mountPointForObserver.insert(observer, cachedObserverUrl);
  63         Q_ASSERT(m_observerForMountPoint.count() == m_mountPointForObserver.count());
  64
  65         connect(observer, &MountPointObserver::destroyed, this, &MountPointObserverCache::slotObserverDestroyed);
  66
  67         if (!m_updateTimer->isActive()) {
  68             m_updateTimer->start(60000); // 1 minute
  69         }
  70
  71         connect(m_updateTimer, &QTimer::timeout, observer, &MountPointObserver::update);
  72     }
  73
  74     return observer;
  75 }
  76
  77 void MountPointObserverCache::slotObserverDestroyed(QObject* observer)
  78 {
  79     Q_ASSERT(m_mountPointForObserver.contains(observer));
  80     const QUrl& url = m_mountPointForObserver.value(observer);
  81     Q_ASSERT(m_observerForMountPoint.contains(url));
  82     m_observerForMountPoint.remove(url);
  83     m_mountPointForObserver.remove(observer);
  84
  85     Q_ASSERT(m_observerForMountPoint.count() == m_mountPointForObserver.count());
  86
  87     if (m_mountPointForObserver.isEmpty()) {
  88         m_updateTimer->stop();
  89     }
  90 }