kio Library API Documentation

KIO::Scheduler Class Reference

The KIO::Scheduler manages io-slaves for the application. More...

#include <scheduler.h>

Inheritance diagram for KIO::Scheduler:

QObject DCOPObject List of all members.

Public Methods

virtual bool process (const QCString &fun, const QByteArray &data, QCString &replyType, QByteArray &replyData)
virtual QCStringList functions ()

Static Public Methods

void doJob (SimpleJob *job)
void scheduleJob (SimpleJob *job)
void cancelJob (SimpleJob *job)
void jobFinished (KIO::SimpleJob *job, KIO::Slave *slave)
void putSlaveOnHold (KIO::SimpleJob *job, const KURL &url)
void removeSlaveOnHold ()
void publishSlaveOnHold ()
KIO::Slave * getConnectedSlave (const KURL &url, const KIO::MetaData &config=MetaData())
void registerWindow (QWidget *wid)
bool connect (const char *signal, const QObject *receiver, const char *member)
bool connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
bool disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
void checkSlaveOnHold (bool b)

Protected Slots

void slotUnregisterWindow (QObject *)

Detailed Description

The KIO::Scheduler manages io-slaves for the application.

It also queues jobs and assigns the job to a slave when one becomes available.

There are 3 possible ways for a job to get a slave:

1. Direct

This is the default. When you create a job the KIO::Scheduler will be notified and will find either an existing slave that is idle or it will create a new slave for the job.

Example:

    TransferJob *job = KIO::get(KURL("http://www.kde.org"));

2. Scheduled

If you create a lot of jobs, you might want not want to have a slave for each job. If you schedule a job, a maximum number of slaves will be created. When more jobs arrive, they will be queued. When a slave is finished with a job, it will be assigned a job from the queue.

Example:

    TransferJob *job = KIO::get(KURL("http://www.kde.org"));
    KIO::Scheduler::scheduleJob(job);

3. Connection Oriented

For some operations it is important that multiple jobs use the same connection. This can only be ensured if all these jobs use the same slave.

You can ask the scheduler to open a slave for connection oriented operations. You can then use the scheduler to assign jobs to this slave. The jobs will be queued and the slave will handle these jobs one after the other.

Example:

    Slave *slave = KIO::Scheduler::getConnectedSlave(
            KURL("pop3://bastian:password@mail.kde.org"));
    TransferJob *job1 = KIO::get(
            KURL("pop3://bastian:password@mail.kde.org/msg1"));
    KIO::Scheduler::assignJobToSlave(slave, job1);
    TransferJob *job2 = KIO::get(
            KURL("pop3://bastian:password@mail.kde.org/msg2"));
    KIO::Scheduler::assignJobToSlave(slave, job2);
    TransferJob *job3 = KIO::get(
            KURL("pop3://bastian:password@mail.kde.org/msg3"));
    KIO::Scheduler::assignJobToSlave(slave, job3);

    // ... Wait for jobs to finish...

    KIO::Scheduler::disconnectSlave(slave);

Note that you need to explicitly disconnect the slave when the connection goes down, so your error handler should contain:

    if (error == KIO::ERR_CONNECTION_BROKEN)
        KIO::Scheduler::disconnectSlave(slave);

See also:
KIO::Slave , KIO::Job

Definition at line 111 of file scheduler.h.


Member Function Documentation

void KIO::Scheduler::doJob SimpleJob   job [inline, static]
 

Register job with the scheduler.

The default is to create a new slave for the job if no slave is available. This can be changed by calling scheduleJob.

Parameters:
job  the job to register

Definition at line 129 of file scheduler.h.

References _doJob().

void KIO::Scheduler::scheduleJob SimpleJob   job [inline, static]
 

Calling ths function makes that job gets scheduled for later execution, if multiple jobs are registered it might wait for other jobs to finish.

Parameters:
job  the job to schedule

Definition at line 138 of file scheduler.h.

References _scheduleJob().

void KIO::Scheduler::cancelJob SimpleJob   job [inline, static]
 

Stop the execution of a job.

Parameters:
job  the job to cancel

Definition at line 145 of file scheduler.h.

References _cancelJob().

void KIO::Scheduler::jobFinished KIO::SimpleJob   job,
KIO::Slave *    slave
[inline, static]
 

Called when a job is done.

Parameters:
job  the finished job
slave  the slave that executed the job

Definition at line 153 of file scheduler.h.

References _jobFinished().

void KIO::Scheduler::putSlaveOnHold KIO::SimpleJob   job,
const KURL   url
[inline, static]
 

Puts a slave on notice.

A next job may reuse this slave if it requests the same URL.

A job can be put on hold after it has emit'ed its mimetype. Based on the mimetype, the program can give control to another component in the same process which can then resume the job by simply asking for the same URL again.

Parameters:
job  the job that should be stopped
url  the URL that is handled by the url

Definition at line 167 of file scheduler.h.

References _putSlaveOnHold().

void KIO::Scheduler::removeSlaveOnHold   [inline, static]
 

Removes any slave that might have been put on hold.

If a slave was put on hold it will be killed.

Definition at line 174 of file scheduler.h.

References _removeSlaveOnHold().

void KIO::Scheduler::publishSlaveOnHold   [inline, static]
 

Send the slave that was put on hold back to KLauncher.

This allows another process to take over the slave and resume the job that was started.

Definition at line 182 of file scheduler.h.

References _publishSlaveOnHold().

Referenced by KRun::foundMimeType().

KIO::Slave* KIO::Scheduler::getConnectedSlave const KURL   url,
const KIO::MetaData   config = MetaData()
[inline, static]
 

Requests a slave for use in connection-oriented mode.

Parameters:
url  This defines the username,password,host & port to connect with.
config  Configuration data for the slave.
Returns:
A pointer to a connected slave or 0 if an error occurred.
See also:
assignJobToSlave() , disconnectSlave()

Definition at line 196 of file scheduler.h.

References _getConnectedSlave().

void KIO::Scheduler::registerWindow QWidget   wid [inline, static]
 

Send the slave that was put on hold back to KLauncher.

This allows another process to take over the slave and resume the job the that was started. Register the mainwindow wid with the KIO subsystem Do not call this, it is called automatically from void KIO::Job::setWindow(QWidget*).

Parameters:
wid  the window to register
Since:
3.1

Definition at line 243 of file scheduler.h.

References _registerWindow().

Referenced by KIO::Job::setWindow().

bool KIO::Scheduler::connect const char *    signal,
const QObject   receiver,
const char *    member
[inline, static]
 

Function to connect signals emitted by the scheduler.

See also:
slaveConnected() , slaveError()

Definition at line 259 of file scheduler.h.

References QObject::connect().

void KIO::Scheduler::checkSlaveOnHold bool    b [inline, static]
 

When true, the next job will check whether KLauncher has a slave on hold that is suitable for the job.

Parameters:
b  true when KLauncher has a job on hold

Definition at line 280 of file scheduler.h.

References _checkSlaveOnHold().

void Scheduler::slotUnregisterWindow QObject   [protected, slot]
 

Since:
3.1

Definition at line 882 of file scheduler.cpp.

References QObject::destroyed(), QObject::disconnect(), QMap< QObject *, long >::end(), QMap< QObject *, long >::find(), and QMap< QObject *, long >::remove().


The documentation for this class was generated from the following files:
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This file is part of the documentation for kio Library Version 3.2.0.
Documentation copyright © 1996-2004 the KDE developers.
Generated on Wed Feb 4 12:35:17 2004 by doxygen 1.2.18 written by Dimitri van Heesch, © 1997-2003