1 files changed, 156 insertions, 0 deletions
diff --git a/kmail/jobscheduler.h b/kmail/jobscheduler.h
new file mode 100644
index 000000000..531e51a52
--- /dev/null
+++ b/kmail/jobscheduler.h
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2004 David Faure <faure@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; version 2 of the License
+ *
+ *  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, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ *  In addition, as a special exception, the copyright holders give
+ *  permission to link the code of this program with any edition of
+ *  the Qt library by Trolltech AS, Norway (or with modified versions
+ *  of Qt that use the same license as Qt), and distribute linked
+ *  combinations including the two.  You must obey the GNU General
+ *  Public License in all respects for all of the code used other than
+ *  Qt.  If you modify this file, you may extend this exception to
+ *  your version of the file, but you are not obligated to do so.  If
+ *  you do not wish to do so, delete this exception statement from
+ *  your version.
+ */
+
+#ifndef KMAIL_JOBSCHEDULER_H
+#define KMAIL_JOBSCHEDULER_H
+
+#include <qobject.h>
+#include <qvaluelist.h>
+#include <qguardedptr.h>
+#include <qtimer.h>
+
+#include "folderjob.h"
+
+// If this define is set, JobScheduler will show debug output, and related kmkernel timers will be shortened
+// This is for debugging purposes only, don't commit with it.
+//#define DEBUG_SCHEDULER
+
+class KMFolder;
+namespace KMail {
+
+class FolderJob;
+class ScheduledJob;
+
+/**
+ * A scheduled task is some information about a folder job that should be run later.
+ * As long as it's not running, it's called a "task", i.e. something that needs to be done.
+ * Tasks are held in the JobScheduler.
+ */
+class ScheduledTask {
+public:
+  /// Create a scheduled task for a given folder
+  /// If @p immediate is true, the scheduler will run this task as soon
+  /// as possible (but won't interrupt a currently running job for it)
+  ScheduledTask( KMFolder* folder, bool immediate )
+    : mCurrentFolder( folder ), mImmediate( immediate ) {}
+  virtual ~ScheduledTask() {}
+
+  /// Run this task, i.e. create a job for it.
+  /// Important: the job's execute() method must either call open() on the
+  /// folder or storage immediately, or abort (deleting itself).
+  /// Usually, that job should also be cancellable.
+  /// Otherwise (if the open() is delayed) an unrelated open() could happen first
+  /// and mess things up.
+  /// If for some reason (e.g. folder deleted) nothing should be done, return 0.
+  virtual ScheduledJob* run() = 0;
+
+  /// An identifier for the type of task (a bit like QListViewItem::rtti)
+  /// This allows to automatically prevent two identical tasks from being scheduled
+  /// for the same folder. To circumvent this feature and make every task
+  /// unique, return 0 here.
+  virtual int taskTypeId() const = 0;
+
+  /// The folder which this task is about, 0 if it was deleted meanwhile.
+  KMFolder* folder() const { return mCurrentFolder; }
+
+  bool isImmediate() const { return mImmediate; }
+
+private:
+  QGuardedPtr<KMFolder> mCurrentFolder;
+  bool mImmediate;
+};
+
+/**
+ * The unique JobScheduler instance (owned by kmkernel) implements "background processing"
+ * of folder operations (like expiration and compaction). Tasks (things to be done)
+ * are registered with the JobScheduler, and it will execute them one at a time,
+ * separated with a 1-minute timer. The jobs themselves should use timers to avoid
+ * using too much CPU for too long. Tasks for opened folders are not executed until
+ * the folder is closed.
+ */
+class JobScheduler : public QObject
+{
+  Q_OBJECT
+public:
+  JobScheduler( QObject* parent, const char* name = 0 );
+  ~JobScheduler();
+
+  /// Register a task to be done for a given folder
+  /// The ownership of the task is transferred to the JobScheduler
+  void registerTask( ScheduledTask* task );
+
+  /// Called by [implementations of] FolderStorage::open()
+  /// Interrupt any running job for this folder and re-schedule it for later
+  void notifyOpeningFolder( KMFolder* folder );
+
+  // DCOP calls
+  void pause();
+  void resume();
+
+private slots:
+  /// Called by a timer to run the next job
+  void slotRunNextJob();
+
+  /// Called when the current job terminates
+  void slotJobFinished();
+
+private:
+  void restartTimer();
+  void interruptCurrentTask();
+  void runTaskNow( ScheduledTask* task );
+  typedef QValueList<ScheduledTask *> TaskList;
+  void removeTask( TaskList::Iterator& it );
+private:
+  TaskList mTaskList; // FIFO of tasks to be run
+
+  QTimer mTimer;
+  int mPendingImmediateTasks;
+
+  /// Information about the currently running job, if any
+  ScheduledTask* mCurrentTask;
+  ScheduledJob* mCurrentJob;
+};
+
+/**
+ * Base class for scheduled jobs
+ */
+class ScheduledJob : public FolderJob
+{
+public:
+  ScheduledJob( KMFolder* folder, bool immediate );
+
+  bool isOpeningFolder() const { return mOpeningFolder; }
+
+protected:
+  bool mImmediate;
+  bool mOpeningFolder;
+};
+
+} // namespace
+
+#endif /* KMAIL_JOBSCHEDULER_H */