jobscheduler.cpp

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#include "jobscheduler.h"
#include <kdebug.h>

namespace MailCommon {

ScheduledTask::ScheduledTask( const Akonadi::Collection& folder, bool immediate )
  : mCurrentFolder( folder ), mImmediate( immediate )
{
}

ScheduledTask::~ScheduledTask()
{
}

JobScheduler::JobScheduler( QObject* parent )
  : QObject( parent ), mTimer( this ),
    mPendingImmediateTasks( 0 ),
    mCurrentTask( 0 ), mCurrentJob( 0 )
{
  connect( &mTimer, SIGNAL(timeout()), SLOT(slotRunNextJob()) );
  // No need to start the internal timer yet, we wait for a task to be scheduled
}


JobScheduler::~JobScheduler()
{
  qDeleteAll( mTaskList );
  mTaskList.clear();
  delete mCurrentTask;
  mCurrentTask = 0;
  delete mCurrentJob;
}

void JobScheduler::registerTask( ScheduledTask* task )
{
  bool immediate = task->isImmediate();
  int typeId = task->taskTypeId();
  if ( typeId ) {
    const Akonadi::Collection folder = task->folder();
    // Search for an identical task already scheduled
    TaskList::Iterator end( mTaskList.end() );
    for ( TaskList::Iterator it = mTaskList.begin(); it != end; ++it ) {
      if ( (*it)->taskTypeId() == typeId && (*it)->folder() == folder ) {
#ifdef DEBUG_SCHEDULER
        kDebug() << "JobScheduler: already having task type" << typeId << "for folder" << folder->label();
#endif
        delete task;
        if ( !mCurrentTask && immediate ) {
          ScheduledTask* task = *it;
          removeTask( it );
          runTaskNow( task );
        }
        return;
      }
    }
    // Note that scheduling an identical task as the one currently running is allowed.
  }
  if ( !mCurrentTask && immediate )
    runTaskNow( task );
  else {
#ifdef DEBUG_SCHEDULER
    kDebug() << "JobScheduler: adding task" << task << "(type" << task->taskTypeId()
                  << ") for folder" << task->folder() << task->folder().name();
#endif
    mTaskList.append( task );
    if ( immediate )
      ++mPendingImmediateTasks;
    if ( !mCurrentTask && !mTimer.isActive() )
      restartTimer();
  }
}

void JobScheduler::removeTask( TaskList::Iterator& it )
{
  if ( (*it)->isImmediate() )
    --mPendingImmediateTasks;
  mTaskList.erase( it );
}

void JobScheduler::interruptCurrentTask()
{
  Q_ASSERT( mCurrentTask );
#ifdef DEBUG_SCHEDULER
  kDebug() << "JobScheduler: interrupting job" << mCurrentJob << "for folder" << mCurrentTask->folder()->label();
#endif
  // File it again. This will either delete it or put it in mTaskList.
  registerTask( mCurrentTask );
  mCurrentTask = 0;
  mCurrentJob->kill(); // This deletes the job and calls slotJobFinished!
}

void JobScheduler::slotRunNextJob()
{
  while ( !mCurrentJob ) {
#ifdef DEBUG_SCHEDULER
    kDebug() << "JobScheduler: slotRunNextJob";
#endif
    Q_ASSERT( mCurrentTask == 0 );
    ScheduledTask* task = 0;
    // Find a task suitable for being run
    TaskList::Iterator end( mTaskList.end() );
    for ( TaskList::Iterator it = mTaskList.begin(); it != end; ++it ) {
      // Remove if folder died
      const Akonadi::Collection folder = (*it)->folder();
      if ( !folder.isValid() ) {
#ifdef DEBUG_SCHEDULER
        kDebug() << "  folder for task" << (*it) << "was deleted";
#endif
        removeTask( it );
        if ( !mTaskList.isEmpty() )
          slotRunNextJob(); // to avoid the mess with invalid iterators :)
        else
          mTimer.stop();
        return;
      }
#ifdef DEBUG_SCHEDULER
      kDebug() << "  looking at folder" << folder.name();
#endif
      task = *it;
      removeTask( it );
      break;
    }

    if ( !task ) // found nothing to run, i.e. folder was opened
      return; // Timer keeps running, i.e. try again in 1 minute

    runTaskNow( task );
  } // If nothing to do for that task, loop and find another one to run
}

void JobScheduler::restartTimer()
{
  if ( mPendingImmediateTasks > 0 )
    slotRunNextJob();
  else
  {
#ifdef DEBUG_SCHEDULER
    mTimer.start( 10000 ); // 10 seconds
#else
    mTimer.start( 1 * 60000 ); // 1 minute
#endif
  }
}

void JobScheduler::runTaskNow( ScheduledTask* task )
{
  Q_ASSERT( mCurrentTask == 0 );
  if ( mCurrentTask ) {
    interruptCurrentTask();
  }
  mCurrentTask = task;
  mTimer.stop();
  mCurrentJob = mCurrentTask->run();
#ifdef DEBUG_SCHEDULER
  kDebug() << "JobScheduler: task" << mCurrentTask
                << "(type" << mCurrentTask->taskTypeId() << ")"
                << "for folder" << mCurrentTask->folder()->label()
                << "returned job" << mCurrentJob
                << ( mCurrentJob?mCurrentJob->className():0 );
#endif
  if ( !mCurrentJob ) { // nothing to do, e.g. folder deleted
    delete mCurrentTask;
    mCurrentTask = 0;
    if ( !mTaskList.isEmpty() )
      restartTimer();
    return;
  }
  // Register the job in the folder. This makes it autodeleted if the folder is deleted.
#if 0
  mCurrentTask->folder()->storage()->addJob( mCurrentJob );
#endif
  connect( mCurrentJob, SIGNAL(finished()), this, SLOT(slotJobFinished()) );
  mCurrentJob->start();
}

void JobScheduler::slotJobFinished()
{
  // Do we need to test for mCurrentJob->error()? What do we do then?
#ifdef DEBUG_SCHEDULER
  kDebug() << "JobScheduler: slotJobFinished";
#endif
  delete mCurrentTask;
  mCurrentTask = 0;
  mCurrentJob = 0;
  if ( !mTaskList.isEmpty() )
    restartTimer();
}

// D-Bus call to pause any background jobs
void JobScheduler::pause()
{
  mPendingImmediateTasks = 0;
  if ( mCurrentJob && mCurrentJob->isCancellable() )
    interruptCurrentTask();
  mTimer.stop();
}

void JobScheduler::resume()
{
  restartTimer();
}


ScheduledJob::ScheduledJob( const Akonadi::Collection& folder, bool immediate )
  : mImmediate( immediate )
{
  mCancellable = true;
  mSrcFolder = folder;
}

ScheduledJob::~ScheduledJob()
{
}

}

#include "jobscheduler.moc"