src/scancontroller.h

   1 /***************************************************************************
   2  *   Copyright (C) 2003-2007 by The Amarok Developers                      *
   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 Steet, Fifth Floor, Boston, MA  02110-1301, USA.          *
  18  ***************************************************************************/
  19
  20 #ifndef AMAROK_SCANCONTROLLER_H
  21 #define AMAROK_SCANCONTROLLER_H
  22
  23 #include <QCustomEvent>
  24 #include <QMutex>
  25 #include <QtXml>         //baseclass
  26
  27 #include "threadmanager.h" //baseclass
  28
  29 class CollectionDB;
  30 class K3ProcIO;
  31
  32 /**
  33  * @class ScanController
  34  * @short Starts and controls the external amarokcollectionscanner application.
  35  * @author Mark Kretschmann <markey@web.de>
  36  *
  37  * The collection scanner itself is run in an external process, unlike before, where it
  38  * used to be thread. The advantage is that the scanner cannot crash the Amarok main
  39  * application any more. If it crashes we can simply restart it.
  40  *
  41  * Amarok communicates with the scanner via the ScanController class, which processes
  42  * XML entities written to stdout by the scanner process. For XML parsing an event
  43  * driven SAX2 parser is used, which can process the entities as they arrive, without
  44  * the need for a DOM document structure.
  45  */
  46
  47 class ScanController : public ThreadManager::DependentJob, public QXmlDefaultHandler
  48 {
  49     Q_OBJECT
  50
  51     public:
  52         static const int RestartEventType = 8891;
  53
  54         class RestartEvent : public QCustomEvent {
  55             public:
  56                 RestartEvent() : QCustomEvent( RestartEventType ) {}
  57         };
  58
  59         static const int PlaylistFoundEventType = 8890;
  60
  61         class PlaylistFoundEvent : public QCustomEvent {
  62             public:
  63                 PlaylistFoundEvent( QString path )
  64                     : QCustomEvent( PlaylistFoundEventType )
  65                     , m_path( path ) {}
  66                 QString path() { return m_path; }
  67             private:
  68                 QString m_path;
  69         };
  70
  71     public:
  72         ScanController( CollectionDB* parent, bool incremental, const QStringList& folders = QStringList() );
  73         ~ScanController();
  74         static ScanController* instance();
  75
  76         virtual void completeJob( void );
  77
  78         bool isIncremental() const { return m_incremental; }
  79         bool hasChanged() const { return m_hasChanged; }
  80
  81         bool tablesCreated() { return m_tablesCreated; }
  82
  83     signals:
  84         void scannerAcknowledged();
  85         void scanDone( bool changed );
  86
  87     public slots:
  88         void slotFileMoved( const QString &src, const QString &dest );
  89
  90     private slots:
  91         void slotReadReady();
  92
  93     private:
  94         void initIncremental();
  95         virtual bool doJob();
  96         static void setInstance( ScanController* instance );
  97
  98         bool startElement( const QString&, const QString &localName, const QString&, const QXmlAttributes &attrs );
  99         void customEvent( QCustomEvent* );
 100
 101         // Member variables:
 102         static const int MAX_RESTARTS = 80;
 103         static const int MAX_FAILURE_PERCENTAGE = 5;
 104
 105         K3ProcIO* m_scanner;
 106         QStringList m_folders;
 107         QStringList m_foldersToRemove;
 108         bool m_incremental;
 109         bool m_hasChanged;
 110
 111         QString m_xmlData;
 112         QMutex m_dataMutex;
 113         QXmlInputSource* m_source;
 114         QXmlSimpleReader* m_reader;
 115
 116         QStringList m_crashedFiles;
 117
 118         // Every file that the collection scanner finds is marked
 119         // here, as well as the source of all files that the AFT code
 120         // detects as having been moved.  These are the files that
 121         // have definitely not been deleted.  The key is the absolute
 122         // path.
 123         QMap<QString,QString> m_filesAdded;
 124         QMap<QString,QString> m_filesDeleted;
 125         QMutex             m_fileMapsMutex;
 126
 127         static ScanController* currController;
 128
 129         bool m_tablesCreated;
 130         int m_scanCount;
 131 };
 132
 133
 134 #endif // AMAROK_SCANCONTROLLER_H