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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems, Inc.
* 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
*/
#ifndef DRIZZLED_PLUGIN_XA_STORAGE_ENGINE_H
#define DRIZZLED_PLUGIN_XA_STORAGE_ENGINE_H
#include "drizzled/plugin/transactional_storage_engine.h"
#include "drizzled/plugin/xa_resource_manager.h"
namespace drizzled
{
class XID;
namespace plugin
{
/**
* A type of storage engine which supports distributed
* transactions in the XA protocol.
*
* The real XA resource manager interface is in the
* plugin::XaResourceManager class. We would extend
* XaResourceManager from plugin::Plugin but unfortunately
* that would lead to member name ambiguity (because plugin::Plugin
* has member data). So, in this case, TransactionalStorageEngine
* inherits from plugin::Plugin and XaResourceManager is a pure
* virtual abstract base class with the X/Open XA distributed
* transaction protocol interface for resource managers.
*/
class XaStorageEngine :public TransactionalStorageEngine,
public XaResourceManager
{
public:
XaStorageEngine(const std::string name_arg,
const std::bitset<HTON_BIT_SIZE> &flags_arg= HTON_NO_FLAGS);
virtual ~XaStorageEngine();
int startTransaction(Session *session, start_transaction_option_t options)
{
TransactionServices &transaction_services= TransactionServices::singleton();
transaction_services.registerResourceForTransaction(*session, this, this, this);
return doStartTransaction(session, options);
}
void startStatement(Session *session)
{
TransactionServices &transaction_services= TransactionServices::singleton();
transaction_services.registerResourceForStatement(*session, this, this, this);
doStartStatement(session);
}
/*
* The below are simple virtual overrides for the plugin::MonitoredInTransaction
* interface.
*/
bool participatesInSqlTransaction() const
{
return true; /* We DO participate in the SQL transaction */
}
bool participatesInXaTransaction() const
{
return true; /* We DO participate in the XA transaction */
}
bool alwaysRegisterForXaTransaction() const
{
return false; /* We only register in the XA transaction if the engine's data is modified */
}
/* Class Methods for operating on plugin */
static bool addPlugin(plugin::XaStorageEngine *engine);
static void removePlugin(plugin::XaStorageEngine *engine);
private:
/*
* Indicates to a storage engine the start of a
* new SQL transaction. This is called ONLY in the following
* scenarios:
*
* 1) An explicit BEGIN WORK/START TRANSACTION is called
* 2) After an explicit COMMIT AND CHAIN is called
* 3) After an explicit ROLLBACK AND RELEASE is called
* 4) When in AUTOCOMMIT mode and directly before a new
* SQL statement is started.
*
* Engines should typically use the doStartStatement()
* and doEndStatement() methods to manage transaction state,
* since the kernel ALWAYS notifies engines at the start
* and end of statement transactions and at the end of the
* normal transaction by calling doCommit() or doRollback().
*/
virtual int doStartTransaction(Session *session, start_transaction_option_t options)
{
(void) session;
(void) options;
return 0;
}
/*
* Indicates to a storage engine the start of a
* new SQL statement.
*/
virtual void doStartStatement(Session *session)
{
(void) session;
}
};
} /* namespace plugin */
} /* namespace drizzled */
#endif /* DRIZZLED_PLUGIN_XA_STORAGE_ENGINE_H */
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