parthelper.h

/***************************************************************************
 *   SPDX-FileCopyrightText: 2009 Andras Mantia <amantia@kde.org>          *
 *                                                                         *
 *   SPDX-License-Identifier: LGPL-2.0-or-later                            *
 ***************************************************************************/
 
#pragma once
 
#include "../exception.h"
#include "entities.h"
 
class QString;
class QVariant;
 
namespace Akonadi
{
namespace Server
{
AKONADI_EXCEPTION_MAKE_INSTANCE(PartHelperException);
 
/**
 * Helper methods that store data in a file instead of the database.
 *
 * @author Andras Mantia <amantia@kde.org>
 *
 * @todo Use exceptions for error handling in all these methods. Requires that all callers
 * can handle that first though.
 */
namespace PartHelper
{
/**
 * Update payload of an existing part @p part to @p data and size @p dataSize.
 * Automatically decides whether or not the data should be stored in the database
 * or the file system.
 * @throw PartHelperException if file operations failed
 */
void update(Part *part, const QByteArray &data, qint64 dataSize);
 
/**
 * Adds a new part to the database and if necessary to the filesystem.
 * @p part must not be in the database yet (ie. valid() == false) and must have
 * a data size set.
 */
bool insert(Part *part, qint64 *insertId = nullptr);
 
/** Deletes @p part from the database and also removes existing filesystem data if needed. */
bool remove(Part *part);
/** Deletes all parts which match the given constraint, including all corresponding filesystem data. */
bool remove(const QString &column, const QVariant &value);
 
/** Returns the payload data. */
QByteArray translateData(const QByteArray &data, Part::Storage storageType);
/** Convenience overload of the above. */
QByteArray translateData(const Part &part);
 
/** Truncate the payload of @p part and update filesystem/database accordingly.
 *  This is more efficient than using update since it does not require the data to be loaded.
 */
bool truncate(Part &part);
 
/** Verifies and if necessary fixes the external reference of this part. */
bool verify(Part &part);
 
} // namespace PartHelper
 
} // namespace Server
} // namespace Akonadi