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/**
* Copyright (C) 2008-2015 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects
* for all of the code used other than as permitted herein. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you do not
* wish to do so, delete this exception statement from your version. If you
* delete this exception statement from all source files in the program,
* then also delete it in the license file.
*/
#pragma once
#include <string>
#include "mongo/base/disallow_copying.h"
#include "mongo/client/connection_string.h"
namespace mongo {
class BSONObj;
class RemoteCommandTargeter;
using ShardId = std::string;
/**
* Contains runtime information obtained from the shard.
*/
class ShardStatus {
public:
ShardStatus(long long dataSizeBytes, const std::string& version);
long long dataSizeBytes() const { return _dataSizeBytes; }
const std::string& mongoVersion() const { return _mongoVersion; }
std::string toString() const;
bool operator< (const ShardStatus& other) const;
private:
long long _dataSizeBytes;
std::string _mongoVersion;
};
class Shard;
using ShardPtr = std::shared_ptr<Shard>;
/*
* Maintains the targeting and command execution logic for a single shard. Performs polling of
* the shard (if replica set).
*/
class Shard {
MONGO_DISALLOW_COPYING(Shard);
public:
/**
* Instantiates a new shard connection management object for the specified shard.
*/
Shard(const ShardId& id,
const ConnectionString& connStr,
std::unique_ptr<RemoteCommandTargeter> targeter);
~Shard();
const ShardId& getId() const { return _id; }
const ConnectionString& getConnString() const { return _cs; }
RemoteCommandTargeter* getTargeter() const { return _targeter.get(); }
BSONObj runCommand(const std::string& db, const std::string& simple) const;
BSONObj runCommand(const std::string& db, const BSONObj& cmd) const;
bool runCommand(const std::string& db, const std::string& simple, BSONObj& res) const;
bool runCommand(const std::string& db, const BSONObj& cmd, BSONObj& res) const;
/**
* Returns metadata and stats for this shard.
*/
ShardStatus getStatus() const;
/**
* Returns a string description of this shard entry.
*/
std::string toString() const;
static ShardPtr lookupRSName(const std::string& name);
/**
* @parm current - shard where the chunk/database currently lives in
* @return the currently emptiest shard, if best then current, or nullptr
*/
static ShardPtr pick();
static void reloadShardInfo();
static void removeShard(const ShardId& id);
private:
/**
* Identifier of the shard as obtained from the configuration data (i.e. shard0000).
*/
const ShardId _id;
/**
* Connection string for the shard.
*/
const ConnectionString _cs;
/**
* Targeter for obtaining hosts from which to read or to which to write.
*/
const std::unique_ptr<RemoteCommandTargeter> _targeter;
};
} // namespace mongo
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