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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008-2009 Sun Microsystems
* Copyright (c) 2009-2010 Jay Pipes <jaypipes@gmail.com>
*
* Authors:
*
* 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_REPLICATION_SERVICES_H
#define DRIZZLED_REPLICATION_SERVICES_H
#include "drizzled/atomics.h"
#include <vector>
namespace drizzled
{
/* some forward declarations needed */
class Session;
class Table;
namespace plugin
{
class TransactionReplicator;
class TransactionApplier;
}
namespace message
{
class Transaction;
}
/**
* This is a class which manages transforming internal
* transactional events into GPB messages and sending those
* events out through registered replicators and appliers.
*/
class ReplicationServices
{
public:
typedef uint64_t GlobalTransactionId;
/**
* Types of messages that can go in the transaction
* log file. Every time something is written into the
* transaction log, it is preceded by a header containing
* the type of message which follows.
*/
enum MessageType
{
TRANSACTION= 1, /* A GPB Transaction Message */
BLOB= 2 /* A BLOB value */
};
typedef std::vector<plugin::TransactionReplicator *> Replicators;
typedef std::vector<plugin::TransactionApplier *> Appliers;
private:
/**
* Atomic boolean set to true if any *active* replicators
* or appliers are actually registered.
*/
atomic<bool> is_active;
/**
* The timestamp of the last time a Transaction message was successfully
* applied (sent to an Applier)
*/
atomic<uint64_t> last_applied_timestamp;
/** Our collection of replicator plugins */
Replicators replicators;
/** Our collection of applier plugins */
Appliers appliers;
/**
* Helper method which is called after any change in the
* registered appliers or replicators to evaluate whether
* any remaining plugins are actually active.
*
* This method properly sets the is_active member variable.
*/
void evaluateActivePlugins();
public:
/**
* Helper method which pushes a constructed message out to the registered
* replicator and applier plugins.
*
* @param Message to push out
*/
void pushTransactionMessage(message::Transaction &to_push);
/**
* Constructor
*/
ReplicationServices();
/**
* Singleton method
* Returns the singleton instance of ReplicationServices
*/
static inline ReplicationServices &singleton()
{
static ReplicationServices replication_services;
return replication_services;
}
/**
* Returns whether the ReplicationServices object
* is active. In other words, does it have both
* a replicator and an applier that are *active*?
*/
bool isActive() const;
/**
* Attaches a replicator to our internal collection of
* replicators.
*
* @param Pointer to a replicator to attach/register
*/
void attachReplicator(plugin::TransactionReplicator *in_replicator);
/**
* Detaches/unregisters a replicator with our internal
* collection of replicators.
*
* @param Pointer to the replicator to detach
*/
void detachReplicator(plugin::TransactionReplicator *in_replicator);
/**
* Attaches a applier to our internal collection of
* appliers.
*
* @param Pointer to a applier to attach/register
*/
void attachApplier(plugin::TransactionApplier *in_applier);
/**
* Detaches/unregisters a applier with our internal
* collection of appliers.
*
* @param Pointer to the applier to detach
*/
void detachApplier(plugin::TransactionApplier *in_applier);
/** Returns the timestamp of the last Transaction which was sent to an
* applier.
*/
uint64_t getLastAppliedTimestamp() const;
};
} /* namespace drizzled */
#endif /* DRIZZLED_REPLICATION_SERVICES_H */
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