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 <QSet>
#include "qgis.h"
#include <QString>
#include <QObject>
#include <QStack>

#include "qgis_core.h"
#include "qgis_sip.h"

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;

    bool addLayer( QgsVectorLayer *layer );

    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 );

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

    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; }

  signals:

    void afterRollback();

    void dirtied( const QString &sql, const QString &name );

  protected:
    QgsTransaction( const QString &connString ) SIP_SKIP;

    QString mConnString;

  private slots:
    void onLayerDeleted();

  private:

    bool mTransactionActive;
    QSet<QgsVectorLayer *> mLayers;

    QStack< QString > mSavepoints;
    bool mLastSavePointIsDirty;

    void setLayerTransactionIds( QgsTransaction *transaction );

    virtual bool beginTransaction( QString &error, int statementTimeout ) = 0;
    virtual bool commitTransaction( QString &error ) = 0;
    virtual bool rollbackTransaction( QString &error ) = 0;
};

#endif // QGSTRANSACTION_H