File indexing completed on 2024-04-28 15:15:37

 // SPDX-FileCopyrightText: 2009 Jens-Michael Hoffmann <jmho@c-xx.com>
 //
 // SPDX-License-Identifier: LGPL-2.1-or-later
 
 #ifndef MARBLE_DOWNLOADQUEUESET_H
 #define MARBLE_DOWNLOADQUEUESET_H
 
 #include <QList>
 #include <QQueue>
 #include <QObject>
 #include <QSet>
 #include <QStack>
 
 #include "DownloadPolicy.h"
 
 class QUrl;
 
 namespace Marble
 {
 
 class HttpJob;
 
 /**
    Life of a HttpJob
    =================
    - Job is added to the QueueSet (by calling addJob() )
      the HttpJob is put into the m_jobQueue where it waits for "activation"
      signal jobAdded is emitted
    - Job is activated
      Job is moved from m_jobQueue to m_activeJobs and signals of the job
      are connected to slots (local or HttpDownloadManager)
      Job is executed by calling the jobs execute() method
 
    now there are different possibilities:
    1) Job emits jobDone (some error occurred, or canceled (kio))
       Job is disconnected
       signal jobRemoved is emitted
       Job is either moved from m_activeJobs to m_retryQueue
         or destroyed and blacklisted
 
    2) Job emits redirected
       Job is removed from m_activeJobs, disconnected and destroyed
       signal jobRemoved is emitted
       (HttpDownloadManager creates new Job with new source url)
 
    3) Job emits dataReceived
       Job is removed from m_activeJobs, disconnected and destroyed
       signal jobRemoved is emitted
 
    so we can conclude following rules:
    - Job is only connected to signals when in "active" state
 
 
    questions:
    - update of initiatorId needed?
      "We update the initiatorId as the previous initiator
       likely doesn't exist anymore"
    - blacklist or black list?
 
  */
 
 class DownloadQueueSet: public QObject
 {
     Q_OBJECT
 
  public:
     explicit DownloadQueueSet( QObject * const parent = nullptr );
     explicit DownloadQueueSet( const DownloadPolicy& policy, QObject * const parent = nullptr );
     ~DownloadQueueSet() override;
 
     DownloadPolicy downloadPolicy() const;
     void setDownloadPolicy( const DownloadPolicy& );
 
     bool canAcceptJob( const QUrl& sourceUrl,
                        const QString& destinationFileName ) const;
     void addJob( HttpJob * const job );
 
     void activateJobs();
     void retryJobs();
     void purgeJobs();
 
  Q_SIGNALS:
     void jobAdded();
     void jobRemoved();
     void jobRetry();
     void jobFinished( const QByteArray& data, const QString& destinationFileName,
                       const QString& id );
     void jobRedirected( const QUrl& newSourceUrl, const QString& destinationFileName,
                         const QString& id, DownloadUsage );
     void progressChanged( int active, int queued );
 
  private Q_SLOTS:
     void finishJob( HttpJob * job, const QByteArray& data );
     void redirectJob( HttpJob * job, const QUrl& newSourceUrl );
     void retryOrBlacklistJob( HttpJob * job, const int errorCode );
 
  private:
     void activateJob( HttpJob * const job );
     void deactivateJob( HttpJob * const job );
     bool jobIsActive( const QString& destinationFileName ) const;
     bool jobIsQueued( const QString& destinationFileName ) const;
     bool jobIsWaitingForRetry( const QString& destinationFileName ) const;
     bool jobIsBlackListed( const QUrl& sourceUrl ) const;
 
     DownloadPolicy m_downloadPolicy;
 
     /** This is the first stage a job enters, from this queue it will get
      *  into the activatedJobs container.
      */
     class JobStack
     {
     public:
         bool contains( const QString& destinationFileName ) const;
         int count() const;
         bool isEmpty() const;
         HttpJob * pop();
         void push( HttpJob * const );
     private:
         QStack<HttpJob*> m_jobs;
         QSet<QString> m_jobsContent;
     };
     JobStack m_jobs;
 
     /// Contains the jobs which are currently being downloaded.
     QList<HttpJob*> m_activeJobs;
 
     /** Contains jobs which failed to download and which are scheduled for
      *  retry according to retry settings.
      */
     QQueue<HttpJob*> m_retryQueue;
 
     /// Contains the blacklisted source urls
     QSet<QString> m_jobBlackList;
 };
 
 }
 
 #endif