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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 "mongo/bson/oid.h"
#include "mongo/bson/timestamp.h"
#include "mongo/db/client.h"
#include "mongo/db/repl/optime.h"
namespace mongo {
class BSONObjBuilder;
class Client;
class OperationContext;
namespace repl {
class ReplClientInfo {
public:
static const Client::Decoration<ReplClientInfo> forClient;
/**
* Sets the LastOp to the provided op, which MUST be greater than or equal to the current value
* of the LastOp. This also marks that the LastOp was set explicitly on the client so we wait
* for write concern.
*/
void setLastOp(OperationContext* opCtx, const OpTime& op);
OpTime getLastOp() const {
return _lastOp;
}
/**
* Stores the operation time of the latest proxy write, that is, a write that was forwarded
* to and executed on a different node instead of being executed locally.
*/
void setLastProxyWriteTimestampForward(const Timestamp& timestamp) {
// Only advance the operation time of the latest proxy write if it is greater than the one
// currently stored.
if (timestamp > _lastProxyWriteTimestamp) {
_lastProxyWriteTimestamp = timestamp;
}
}
/**
* Returns the greater of the timestamps set by 'setLastOp()' and
* 'setLastProxyWriteTimestampForward()'.
*/
Timestamp getMaxKnownOperationTime() const {
auto lastOpTimestamp = _lastOp.getTimestamp();
return lastOpTimestamp > _lastProxyWriteTimestamp ? lastOpTimestamp
: _lastProxyWriteTimestamp;
}
/**
* Returns true when either setLastOp() or setLastOpToSystemLastOpTime() was called to set the
* opTime under the current OperationContext.
*/
bool lastOpWasSetExplicitlyByClientForCurrentOperation(OperationContext* opCtx) const;
/**
* Resets the last op on this client.
* WARNING: This should only be used when the lastOp is no longer needed for the client.
*/
void clearLastOp() {
_lastOp = OpTime();
}
/**
* Use this to set the LastOp to the latest known OpTime in the oplog. On primary, The OpTime
* used consists of the timestamp of the latest oplog entry on disk and the current term. On
* secondaries, lastAppliedOpTime is used. Using lastAppliedOpTime on secondaries is the desired
* behavior, since secondaries do timestamped reads at the lastApplied.
*
* Setting the lastOp to the latest OpTime is necessary when doing no-op writes, as we need to
* set the client's lastOp to a proper value for write concern wait to work.
*
* An exception to this are multi-document transactions, which do a noop write at commit time
* and advance the client's lastOp in case the transaction resulted in a no-op.
*/
void setLastOpToSystemLastOpTime(OperationContext* opCtx);
/**
* Same as setLastOpToSystemLastOpTime but ignores errors if the OperationContext is
* interrupted.
*/
void setLastOpToSystemLastOpTimeIgnoringCtxInterrupted(OperationContext* opCtx);
private:
static const long long kUninitializedTerm = -1;
OpTime _lastOp = OpTime();
Timestamp _lastProxyWriteTimestamp;
};
} // namespace repl
} // namespace mongo
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