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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2010 Jay Pipes <jaypipes@gmail.com>
*
* 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; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#pragma once
#include <cstring>
#include <drizzled/visibility.h>
namespace drizzled
{
namespace plugin
{
extern size_t num_trx_monitored_objects;
/**
* An abstract interface class for those objects which are tracked
* by the TransactionServices component during operations in a
* transaction.
*
* Note that both non-transactional plugin::StorageEngines, non-XA
* plugin::TransactionalStorageEngines, and plugin::XaResourceManager
* objects are all tracked by the transaction manager in TransactionServices.
*
* Implementing classes should inherit *publically* from
* plugin::MonitoredInTransaction, as public inheritance means
* "is a" and is the appropriate use here since all implementing classes
* *are* monitored in a transaction...
*/
class DRIZZLED_API MonitoredInTransaction
{
public:
MonitoredInTransaction();
virtual ~MonitoredInTransaction() {}
/**
* Returns true if the class should participate
* in the SQL transaction.
*/
virtual bool participatesInSqlTransaction() const= 0;
/**
* Returns true if the class should participate
* in the XA transaction.
*/
virtual bool participatesInXaTransaction() const= 0;
/**
* Returns true if the class should be registered
* for every XA transaction regardless of whether
* the class modifies the server's state.
*
* @note
*
* As an example, the XaTransactionApplier plugin class returns
* true for this virtual method. Even though it does not
* change the result of the transaction (it simply is logging
* the changes made by other resource managers), the applier
* plugin should be enlisted in all XA transactions in order
* to be able to rollback or recover its logging activity
* properly.
*/
virtual bool alwaysRegisterForXaTransaction() const= 0;
/**
* Returns the "slot" or ID of the monitored resource
*/
size_t getId() const
{
return id;
}
private:
/**
* The ID or "slot" of the plugin.
*
* @todo
*
* Maybe move this into plugin::Plugin? Only issue then is
* that all plugins would have a ha_data slot, when only a few
* actually need that. Maybe create a plugin::NeedsSessionData?
*/
size_t id;
};
} /* namespace plugin */
} /* namespace drizzled */
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