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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* 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 Server Side 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/s/client/shard.h"
#include "mongo/base/disallow_copying.h"
#include "mongo/executor/task_executor.h"
#include "mongo/stdx/mutex.h"
namespace mongo {
/*
* Maintains the targeting and command execution logic for a single shard. Performs polling of
* the shard (if replica set).
*/
class ShardRemote : public Shard {
MONGO_DISALLOW_COPYING(ShardRemote);
public:
/**
* Instantiates a new shard connection management object for the specified shard.
*/
ShardRemote(const ShardId& id,
const ConnectionString& originalConnString,
std::unique_ptr<RemoteCommandTargeter> targeter);
~ShardRemote();
const ConnectionString getConnString() const override;
const ConnectionString originalConnString() const override {
return _originalConnString;
}
std::shared_ptr<RemoteCommandTargeter> getTargeter() const override {
return _targeter;
}
void updateReplSetMonitor(const HostAndPort& remoteHost,
const Status& remoteCommandStatus) override;
std::string toString() const override;
bool isRetriableError(ErrorCodes::Error code, RetryPolicy options) final;
Status createIndexOnConfig(OperationContext* opCtx,
const NamespaceString& ns,
const BSONObj& keys,
bool unique) override;
void updateLastCommittedOpTime(LogicalTime lastCommittedOpTime) final;
LogicalTime getLastCommittedOpTime() const final;
void runFireAndForgetCommand(OperationContext* opCtx,
const ReadPreferenceSetting& readPref,
const std::string& dbName,
const BSONObj& cmdObj) final;
private:
struct AsyncCmdHandle {
HostAndPort hostTargetted;
executor::TaskExecutor::CallbackHandle handle;
};
/**
* Returns the metadata that should be used when running commands against this shard with
* the given read preference.
*/
BSONObj _appendMetadataForCommand(OperationContext* opCtx,
const ReadPreferenceSetting& readPref);
StatusWith<Shard::CommandResponse> _runCommand(OperationContext* opCtx,
const ReadPreferenceSetting& readPref,
const std::string& dbname,
Milliseconds maxTimeMSOverride,
const BSONObj& cmdObj) final;
StatusWith<Shard::QueryResponse> _runExhaustiveCursorCommand(
OperationContext* opCtx,
const ReadPreferenceSetting& readPref,
const std::string& dbName,
Milliseconds maxTimeMSOverride,
const BSONObj& cmdObj) final;
StatusWith<QueryResponse> _exhaustiveFindOnConfig(
OperationContext* opCtx,
const ReadPreferenceSetting& readPref,
const repl::ReadConcernLevel& readConcernLevel,
const NamespaceString& nss,
const BSONObj& query,
const BSONObj& sort,
boost::optional<long long> limit) final;
StatusWith<AsyncCmdHandle> _scheduleCommand(
OperationContext* opCtx,
const ReadPreferenceSetting& readPref,
const std::string& dbName,
Milliseconds maxTimeMSOverride,
const BSONObj& cmdObj,
const executor::TaskExecutor::RemoteCommandCallbackFn& cb);
/**
* Protects _lastCommittedOpTime.
*/
mutable stdx::mutex _lastCommittedOpTimeMutex;
/**
* Logical time representing the latest opTime timestamp known to be in this shard's majority
* committed snapshot. Only the latest time is kept because lagged secondaries may return earlier
* times.
*/
LogicalTime _lastCommittedOpTime;
/**
* Connection string for the shard at the creation time.
*/
const ConnectionString _originalConnString;
/**
* Targeter for obtaining hosts from which to read or to which to write.
*/
const std::shared_ptr<RemoteCommandTargeter> _targeter;
};
} // namespace mongo
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