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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/db/session_catalog.h"
namespace mongo {
class SessionsCollection;
class MongoDSessionCatalog {
public:
/**
* Invoked when the node enters the primary state. Ensures that the transactions collection is
* created. Throws on severe exceptions due to which it is not safe to continue the step-up
* process.
*/
static void onStepUp(OperationContext* opCtx);
/**
* Fetches the UUID of the transaction table, or an empty optional if the collection does not
* exist or has no UUID. Acquires a lock on the collection.
*
* Required for rollback via refetch.
*/
static boost::optional<UUID> getTransactionTableUUID(OperationContext* opCtx);
/**
* Callback to be invoked in response to insert/update/delete of 'config.transactions' in order
* to notify the session catalog that the on-disk contents are out of sync with the in-memory
* state. The 'singleSessionDoc' must contain the _id of the session which was updated.
*/
static void observeDirectWriteToConfigTransactions(OperationContext* opCtx,
BSONObj singleSessionDoc);
/**
* Callback to be invoked when the contents of 'config.transactions' are out of sync with that
* in the in-memory catalog, such as when rollback happens or drop of 'config.transactions'.
*/
static void invalidateAllSessions(OperationContext* opCtx);
/**
* Locates session entries from the in-memory catalog and in 'config.transactions' which have
* not been referenced before 'possiblyExpired' and deletes them.
*
* Returns the number of sessions, which were reaped from the persisted store on disk.
*/
static int reapSessionsOlderThan(OperationContext* opCtx,
SessionsCollection& sessionsCollection,
Date_t possiblyExpired);
};
/**
* Scoped object, which checks out the session specified in the passed operation context and stores
* it for later access by the command. The session is installed at construction time and is removed
* at destruction.
*/
class MongoDOperationContextSession {
public:
MongoDOperationContextSession(OperationContext* opCtx);
~MongoDOperationContextSession();
/**
* This method takes an operation context with a checked-out session and allows it to be
* temporarily or permanently checked back in, in order to allow other operations to use it.
*
* May only be called if the session has actually been checked out previously.
*/
static void checkIn(OperationContext* opCtx);
/**
* May only be called if the session is not checked out already. 'cmdType' is used to validate
* that the expected transaction flow control is being obeyed.
*/
static void checkOut(OperationContext* opCtx, const std::string& cmdName);
private:
OperationContextSession _operationContextSession;
};
/**
* Similar to MongoDOperationContextSession, but marks the TransactionParticipant as valid without
* refreshing from disk and starts a new transaction unconditionally.
*
* NOTE: Only used by the replication oplog application logic on secondaries in order to replay
* prepared transactions.
*/
class MongoDOperationContextSessionWithoutRefresh {
public:
MongoDOperationContextSessionWithoutRefresh(OperationContext* opCtx);
~MongoDOperationContextSessionWithoutRefresh();
private:
OperationContextSession _operationContextSession;
OperationContext* const _opCtx;
};
} // namespace mongo
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