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tdepim/kmail/jobscheduler.h

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/*
* 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 TQt library by Trolltech AS, Norway (or with modified versions
* of TQt that use the same license as TQt), 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
* TQt. 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 <tqobject.h>
#include <tqvaluelist.h>
#include <tqguardedptr.h>
#include <tqtimer.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 TQListViewItem::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:
TQGuardedPtr<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 TQObject
{
Q_OBJECT
public:
JobScheduler( TQObject* 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 TQValueList<ScheduledTask *> TaskList;
void removeTask( TaskList::Iterator& it );
private:
TaskList mTaskList; // FIFO of tasks to be run
TQTimer 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 */