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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.
*/
#include "mongo/platform/basic.h"
#include <boost/optional.hpp>
#include "mongo/s/at_cluster_time_util.h"
#include "mongo/db/logical_clock.h"
#include "mongo/s/grid.h"
#include "mongo/s/shard_id.h"
namespace mongo {
namespace at_cluster_time_util {
namespace {
const char kReadConcernLevelSnapshotName[] = "snapshot";
LogicalTime _computeAtClusterTime(OperationContext* opCtx,
bool mustRunOnAll,
const std::set<ShardId>& shardIds,
const NamespaceString& nss,
const BSONObj query,
const BSONObj collation) {
// TODO SERVER-36312: Re-enable algorithm using the cached opTimes of the targeted shards.
// TODO SERVER-37549: Use the shard's cached lastApplied opTime instead of lastCommitted.
return LogicalClock::get(opCtx)->getClusterTime();
}
} // namespace
BSONObj appendAtClusterTime(BSONObj cmdObj, LogicalTime atClusterTime) {
BSONObjBuilder cmdAtClusterTimeBob;
for (auto el : cmdObj) {
if (el.fieldNameStringData() == repl::ReadConcernArgs::kReadConcernFieldName) {
BSONObjBuilder readConcernBob =
cmdAtClusterTimeBob.subobjStart(repl::ReadConcernArgs::kReadConcernFieldName);
for (auto&& elem : el.Obj()) {
// afterClusterTime cannot be specified with atClusterTime.
if (elem.fieldNameStringData() !=
repl::ReadConcernArgs::kAfterClusterTimeFieldName) {
readConcernBob.append(elem);
}
}
// Transactions will upconvert a read concern with afterClusterTime but no level to have
// level snapshot, so a command may have a read concern field with no level.
//
// TODO SERVER-37237: Once read concern handling has been consolidated on mongos, this
// assertion can probably be removed.
if (!readConcernBob.hasField(repl::ReadConcernArgs::kLevelFieldName)) {
readConcernBob.append(repl::ReadConcernArgs::kLevelFieldName,
kReadConcernLevelSnapshotName);
}
readConcernBob.append(repl::ReadConcernArgs::kAtClusterTimeFieldName,
atClusterTime.asTimestamp());
} else {
cmdAtClusterTimeBob.append(el);
}
}
return cmdAtClusterTimeBob.obj();
}
boost::optional<LogicalTime> computeAtClusterTime(OperationContext* opCtx,
bool mustRunOnAll,
const std::set<ShardId>& shardIds,
const NamespaceString& nss,
const BSONObj query,
const BSONObj collation) {
auto atClusterTime =
_computeAtClusterTime(opCtx, mustRunOnAll, shardIds, nss, query, collation);
// If the user passed afterClusterTime, atClusterTime must be greater than or equal to it.
const auto afterClusterTime = repl::ReadConcernArgs::get(opCtx).getArgsAfterClusterTime();
if (afterClusterTime && *afterClusterTime > atClusterTime) {
return afterClusterTime;
}
return atClusterTime;
}
boost::optional<LogicalTime> computeAtClusterTimeForOneShard(OperationContext* opCtx,
const ShardId& shardId) {
// TODO SERVER-36312: Re-enable algorithm using the cached opTimes of the targeted shard.
// TODO SERVER-37549: Use the shard's cached lastApplied opTime instead of lastCommitted.
auto atClusterTime = LogicalClock::get(opCtx)->getClusterTime();
// If the user passed afterClusterTime, atClusterTime must be greater than or equal to it.
const auto afterClusterTime = repl::ReadConcernArgs::get(opCtx).getArgsAfterClusterTime();
if (afterClusterTime && *afterClusterTime > atClusterTime) {
return afterClusterTime;
}
return atClusterTime;
}
} // namespace at_cluster_time_util
} // namespace mongo
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