qgstransaction.h

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/***************************************************************************
                              qgstransaction.h
                              ----------------
  begin                : May 5, 2014
  copyright            : (C) 2014 by Marco Hugentobler
  email                : marco dot hugentobler at sourcepole dot ch
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   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; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#ifndef QGSTRANSACTION_H
#define QGSTRANSACTION_H
 
#include "qgis_core.h"
#include "qgis_sip.h"
 
#include <QObject>
#include <QSet>
#include <QStack>
#include <QString>
 
class QgsVectorDataProvider;
class QgsVectorLayer;

 
class CORE_EXPORT QgsTransaction : public QObject SIP_ABSTRACT
{
    Q_OBJECT
 
  public:

    static QgsTransaction *create( const QString &connString, const QString &providerKey ) SIP_FACTORY;

    static QgsTransaction *create( const QSet<QgsVectorLayer *> &layers ) SIP_FACTORY;
 
    ~QgsTransaction() override;

    QString connectionString() const;

    bool addLayer( QgsVectorLayer *layer, bool addLayersInEditMode = false );

    bool begin( QString &errorMsg SIP_OUT, int statementTimeout = 20 );

    bool commit( QString &errorMsg SIP_OUT );

    bool rollback( QString &errorMsg SIP_OUT );

    virtual bool executeSql( const QString &sql, QString &error SIP_OUT, bool isDirty = false, const QString &name = QString() ) = 0;

    static bool supportsTransaction( const QgsVectorLayer *layer );

    QString createSavepoint( QString &error SIP_OUT );

    virtual QString createSavepoint( const QString &savePointId, QString &error SIP_OUT );

    virtual bool rollbackToSavepoint( const QString &name, QString &error SIP_OUT );

    void dirtyLastSavePoint();

    QList< QString > savePoints() const { return QList< QString >::fromVector( mSavepoints ); }

    bool lastSavePointIsDirty() const { return mLastSavePointIsDirty; }

    // For internal use only, or by QgsTransactionGroup
    static QString connectionString( const QString &layerUri ) SIP_SKIP;
 
  signals:

    void afterRollback();

    void afterRollbackToSavepoint( const QString &savepointName );

    void dirtied( const QString &sql, const QString &name );
 
  protected:
    QgsTransaction( const QString &connString ) SIP_SKIP;
 
    QString mConnString;
    bool mTransactionActive = false;
    QStack< QString > mSavepoints;
    bool mLastSavePointIsDirty = true;
 
  private slots:
    void onLayerDeleted();
 
  private:
 
    QSet<QgsVectorLayer *> mLayers;
 
    void setLayerTransactionIds( QgsTransaction *transaction );
 
    static QString cleanupConnectionString( const QString &str );
 
    virtual bool beginTransaction( QString &error, int statementTimeout ) = 0;
    virtual bool commitTransaction( QString &error ) = 0;
    virtual bool rollbackTransaction( QString &error ) = 0;
};
 
#endif // QGSTRANSACTION_H