2017-07-06 11:25:36 +03:00

134 lines
3.2 KiB
C++

#pragma once
/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
*
* Change Date: 2020-01-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
#include <maxscale/cppdefs.hh>
#include <tr1/unordered_map>
#include <string>
#include <list>
#include <maxscale/service.h>
#include <maxscale/hashtable.h>
#include <maxscale/spinlock.hh>
using namespace maxscale;
/** This contains the database to server mapping */
typedef std::tr1::unordered_map<std::string, SERVER*> ServerMap;
class Shard
{
public:
Shard();
~Shard();
/**
* @brief Add a database location
*
* @param db Database to add
* @param target Target where database is located
*
* @return True if location was added
*/
bool add_location(std::string db, SERVER* target);
/**
* @brief Retrieve the location of a database
*
* @param db Database to locate
*
* @return The database or NULL if no server contains the database
*/
SERVER* get_location(std::string db);
/**
* @brief Change the location of a database
*
* @param db Database to relocate
* @param target Target where database is relocated to
*/
void replace_location(std::string db, SERVER* target);
/**
* @brief Check if shard contains stale information
*
* @param max_interval The maximum lifetime of the shard
*
* @return True if the shard is stale
*/
bool stale(double max_interval) const;
/**
* @brief Check if shard is empty
*
* @return True if shard contains no locations
*/
bool empty() const;
/**
* @brief Retrieve all database to server mappings
*
* @param keys A map where the database to server mappings are added
*/
void get_content(ServerMap& dest);
/**
* @brief Check if this shard is newer than the other shard
*
* @param shard The other shard to check
*
* @return True if this shard is newer
*/
bool newer_than(const Shard& shard) const;
private:
ServerMap m_map;
time_t m_last_updated;
};
typedef std::tr1::unordered_map<std::string, Shard> ShardMap;
class ShardManager
{
public:
ShardManager();
~ShardManager();
/**
* @brief Retrieve or create a shard
*
* @param user User whose shard to retrieve
* @param max_lifetime The maximum lifetime of a shard
*
* @return The latest version of the shard or a newly created shard if no
* old version is available
*/
Shard get_shard(std::string user, double max_lifetime);
/**
* @brief Update the shard information
*
* The shard information is updated if the new shard contains more up to date
* information than the one stored in the shard manager.
*
* @param shard New version of the shard
* @param user The user whose shard this is
*/
void update_shard(Shard& shard, std::string user);
private:
SPINLOCK m_lock;
ShardMap m_maps;
};