File indexing completed on 2022-08-04 15:34:39

 /**
  * Copyright (C) 2002-2004 Scott Wheeler <wheeler@kde.org>
  * Copyright (C) 2008, 2013 Michael Pyne <mpyne@kde.org>
  *
  * This program is free software; you can redistribute it and/or modify it under
  * the terms of the GNU General Public License as published by the Free Software
  * Foundation; either version 2 of the License, or (at your option) any later
  * version.
  *
  * This program is distributed in the hope that it will be useful, but WITHOUT ANY
  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
  * PARTICULAR PURPOSE. See the GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "cache.h"
 #include "juk-exception.h"
 
 #include <kmessagebox.h>
 #include <kconfig.h>
 #include <ktoggleaction.h>
 #include <KLocalizedString>
 
 #include <QDir>
 #include <QBuffer>
 #include <QtGlobal>
 #include <QSaveFile>
 
 #include "juktag.h"
 #include "searchplaylist.h"
 #include "historyplaylist.h"
 #include "upcomingplaylist.h"
 #include "folderplaylist.h"
 #include "playlistcollection.h"
 #include "actioncollection.h"
 #include "juk.h"
 #include "juk_debug.h"
 
 using namespace ActionCollection;
 
 const int Cache::playlistListCacheVersion = 3;
 const int Cache::playlistItemsCacheVersion = 2;
 
 enum PlaylistType
 {
     Normal   = 0,
     Search   = 1,
     History  = 2,
     Upcoming = 3,
     Folder   = 4
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 // public methods
 ////////////////////////////////////////////////////////////////////////////////
 
 Cache *Cache::instance()
 {
     static Cache cache;
     return &cache;
 }
 
 static void parsePlaylistStream(QDataStream &s, PlaylistCollection *collection)
 {
     while(!s.atEnd()) {
         qint32 playlistType;
         s >> playlistType;
 
         Playlist *playlist = nullptr;
 
         switch(playlistType) {
         case Search:
         {
             SearchPlaylist *p = new SearchPlaylist(collection, *(new PlaylistSearch(JuK::JuKInstance())));
             s >> *p;
             playlist = p;
             break;
         }
         case History:
         {
             action<KToggleAction>("showHistory")->setChecked(true);
             collection->setHistoryPlaylistEnabled(true);
             s >> *collection->historyPlaylist();
             playlist = collection->historyPlaylist();
             break;
         }
         case Upcoming:
         {
             /*
             collection->setUpcomingPlaylistEnabled(true);
             Playlist *p = collection->upcomingPlaylist();
             action<KToggleAction>("saveUpcomingTracks")->setChecked(true);
             s >> *p;
             playlist = p;
             */
             break;
         }
         case Folder:
         {
             FolderPlaylist *p = new FolderPlaylist(collection);
             s >> *p;
             playlist = p;
             break;
         }
         default:
             Playlist *p = new Playlist(collection, true);
             s >> *p;
 
             // We may have already read this playlist from the folder
             // scanner, if an .m3u playlist
             if(collection->containsPlaylistFile(p->fileName())) {
                 delete p;
                 p = nullptr;
             }
 
             playlist = p;
             break;
         } // switch
 
         qint32 sortColumn;
         s >> sortColumn;
         if(playlist)
             playlist->sortByColumn(sortColumn);
     }
 }
 
 void Cache::loadPlaylists(PlaylistCollection *collection) // static
 {
     const QString playlistsFile = playlistsCacheFileName();
     QFile f(playlistsFile);
 
     if(!f.open(QIODevice::ReadOnly))
         return;
 
     QDataStream fs(&f);
 
     qint32 version;
     fs >> version;
 
     if(version != 3 || fs.status() != QDataStream::Ok) {
         // Either the file is corrupt or is from a truly ancient version
         // of JuK.
         qCWarning(JUK_LOG) << "Found the playlist cache but it was clearly corrupt.";
         return;
     }
 
     // Our checksum is only for the values after the version and checksum so
     // we want to get a byte array with just the checksummed data.
 
     QByteArray data;
     quint16 checksum;
     fs >> checksum >> data;
 
     if(fs.status() != QDataStream::Ok || checksum != qChecksum(data.data(), data.size()))
         return;
 
     QDataStream s(&data, QIODevice::ReadOnly);
     s.setVersion(QDataStream::Qt_4_3);
 
     try { // Loading failures are indicated by an exception
         parsePlaylistStream(s, collection);
     }
     catch(BICStreamException &) {
         qCCritical(JUK_LOG) << "Exception loading playlists - binary incompatible stream.";
         // TODO Restructure the Playlist data model and PlaylistCollection data model
         // to be separate from the view/controllers.
         return;
     }
 }
 
 void Cache::savePlaylists(const PlaylistList &playlists)
 {
     QString playlistsFile = playlistsCacheFileName();
     QSaveFile f(playlistsFile);
 
     if(!f.open(QIODevice::WriteOnly)) {
         qCCritical(JUK_LOG) << "Error saving collection:" << f.errorString();
         return;
     }
 
     QByteArray data;
     QDataStream s(&data, QIODevice::WriteOnly);
     s.setVersion(QDataStream::Qt_4_3);
 
     for(const auto &it : playlists) {
         if(!(it)) {
             continue;
         }
         // TODO back serialization type into Playlist itself
         if(dynamic_cast<HistoryPlaylist *>(it)) {
             s << qint32(History)
                 << *static_cast<HistoryPlaylist *>(it);
         }
         else if(dynamic_cast<SearchPlaylist *>(it)) {
             s << qint32(Search)
                 << *static_cast<SearchPlaylist *>(it);
         }
         else if(dynamic_cast<UpcomingPlaylist *>(it)) {
             if(!action<KToggleAction>("saveUpcomingTracks")->isChecked())
                 continue;
             s << qint32(Upcoming)
                 << *static_cast<UpcomingPlaylist *>(it);
         }
         else if(dynamic_cast<FolderPlaylist *>(it)) {
             s << qint32(Folder)
                 << *static_cast<FolderPlaylist *>(it);
         }
         else {
             s << qint32(Normal)
                 << *(it);
         }
         s << qint32(it->sortColumn());
     }
 
     QDataStream fs(&f);
     fs << qint32(playlistListCacheVersion);
     fs << qChecksum(data.data(), data.size());
 
     fs << data;
 
     if(!f.commit())
         qCCritical(JUK_LOG) << "Error saving collection:" << f.errorString();
 }
 
 void Cache::ensureAppDataStorageExists() // static
 {
     QString dirPath = QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation);
     QDir appDataDir(dirPath);
 
     if(!appDataDir.exists() && !appDataDir.mkpath(dirPath))
         qCCritical(JUK_LOG) << "Unable to create appdata storage in" << dirPath;
 }
 
 bool Cache::cacheFileExists() // static
 {
     return QFile::exists(fileHandleCacheFileName());
 }
 
 // Despite the 'Cache' class name, these data files are not regenerable and so
 // should not be stored in cache directory.
 QString Cache::fileHandleCacheFileName() // static
 {
     return QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation) + "/cache";
 }
 
 QString Cache::playlistsCacheFileName() // static
 {
     return QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation) + "/playlists";
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // private methods
 ////////////////////////////////////////////////////////////////////////////////
 
 Cache::Cache()
 {
 
 }
 
 bool Cache::prepareToLoadCachedItems()
 {
     m_loadFile.setFileName(fileHandleCacheFileName());
     if(!m_loadFile.open(QIODevice::ReadOnly))
         return false;
 
     m_loadDataStream.setDevice(&m_loadFile);
 
     int dataStreamVersion = CacheDataStream::Qt_3_3;
 
     qint32 version;
     m_loadDataStream >> version;
 
     switch(version) {
     case 2:
         dataStreamVersion = CacheDataStream::Qt_4_3;
 #if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
         Q_FALLTHROUGH();
 #endif
 
         // Other than that we're compatible with cache v1, so fallthrough
         // to setCacheVersion
 
     case 1: {
         m_loadDataStream.setCacheVersion(1);
         m_loadDataStream.setVersion(dataStreamVersion);
 
         qint32 checksum;
         m_loadDataStream >> checksum
           >> m_loadFileBuffer.buffer();
 
         m_loadFileBuffer.open(QIODevice::ReadOnly);
         m_loadDataStream.setDevice(&m_loadFileBuffer);
 
         qint32 checksumExpected = qChecksum(
                 m_loadFileBuffer.data(), m_loadFileBuffer.size());
         if(m_loadDataStream.status() != CacheDataStream::Ok ||
                 checksum != checksumExpected)
         {
             qCCritical(JUK_LOG) << "Music cache checksum expected to get" << checksumExpected <<
                         "actually was" << checksum;
             KMessageBox::error(0, i18n("The music data cache has been corrupted. JuK "
                                        "needs to rescan it now. This may take some time."));
             return false;
         }
 
         break;
     }
     default: {
         m_loadDataStream.device()->reset();
         m_loadDataStream.setCacheVersion(0);
 
         // This cache is so old that this is just a wild guess here that 3.3
         // is compatible.
         m_loadDataStream.setVersion(CacheDataStream::Qt_3_3);
         break;
     }
     }
 
     return true;
 }
 
 FileHandle Cache::loadNextCachedItem()
 {
     if(!m_loadFile.isOpen() || !m_loadDataStream.device()) {
         qCWarning(JUK_LOG) << "Already completed reading cache file.";
         return FileHandle();
     }
 
     if(m_loadDataStream.status() == QDataStream::ReadCorruptData) {
         qCCritical(JUK_LOG) << "Attempted to read file handle from corrupt cache file.";
         return FileHandle();
     }
 
     if(!m_loadDataStream.atEnd()) {
         QString fileName;
         m_loadDataStream >> fileName;
         fileName.squeeze();
 
         return FileHandle(fileName, m_loadDataStream);
     }
     else {
         m_loadDataStream.setDevice(0);
         m_loadFile.close();
 
         return FileHandle();
     }
 }
 
 // vim: set et sw=4 tw=0 sta: