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/**
* Copyright (C) 2020-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/commands.h"
#include "mongo/db/commands/tenant_migration_donor_cmds_gen.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/repl/tenant_migration_access_blocker_by_prefix.h"
#include "mongo/db/repl/tenant_migration_conflict_info.h"
#include "mongo/db/repl/tenant_migration_state_machine_gen.h"
#include "mongo/executor/task_executor.h"
#include "mongo/rpc/get_status_from_command_result.h"
#include "mongo/rpc/reply_builder_interface.h"
namespace mongo {
namespace tenant_migration_donor {
/**
* Creates a task executor to be used for a tenant migration.
*/
std::unique_ptr<executor::TaskExecutor> makeTenantMigrationExecutor(ServiceContext* serviceContext);
/**
* Updates the TenantMigrationAccessBlocker for the tenant migration represented by the given
* config.migrationDonors document.
*/
void onDonorStateTransition(OperationContext* opCtx, const BSONObj& doc);
/**
* If the operation has read concern "snapshot" or includes afterClusterTime, and the database is
* in the read blocking state at the given atClusterTime or afterClusterTime or the selected read
* timestamp, blocks until the migration is committed or aborted.
*/
void checkIfCanReadOrBlock(OperationContext* opCtx, StringData dbName);
/**
* If the operation has read concern "linearizable", throws TenantMigrationCommitted error if the
* database has been migrated to a different replica set.
*/
void checkIfLinearizableReadWasAllowedOrThrow(OperationContext* opCtx, StringData dbName);
/**
* Throws TenantMigrationConflict if the database is being migrated and the migration is in the
* blocking state. Throws TenantMigrationCommitted if it is in committed.
*/
void onWriteToDatabase(OperationContext* opCtx, StringData dbName);
/**
* Runs the argument function 'callable'. If it throws a TenantMigrationConflict error (as indicated
* in 'replyBuilder'), clears 'replyBuilder' and blocks until the migration commits or aborts, then
* throws TenantMigrationCommitted or TenantMigrationAborted.
*/
template <typename Callable>
void migrationConflictHandler(OperationContext* opCtx,
StringData dbName,
Callable&& callable,
rpc::ReplyBuilderInterface* replyBuilder) {
checkIfCanReadOrBlock(opCtx, dbName);
auto& mtabByPrefix = TenantMigrationAccessBlockerByPrefix::get(opCtx->getServiceContext());
try {
// callable will modify replyBuilder.
callable();
auto replyBodyBuilder = replyBuilder->getBodyBuilder();
// getStatusFromWriteCommandReply expects an 'ok' field.
CommandHelpers::extractOrAppendOk(replyBodyBuilder);
// Commands such as insert, update, delete, and applyOps return the result as a status
// rather than throwing.
const auto status = getStatusFromWriteCommandReply(replyBodyBuilder.asTempObj());
if (status == ErrorCodes::TenantMigrationConflict) {
uassertStatusOK(status);
}
return;
} catch (const TenantMigrationConflictException& ex) {
auto migrationConflictInfo = ex.extraInfo<TenantMigrationConflictInfo>();
invariant(migrationConflictInfo);
if (auto mtab = mtabByPrefix.getTenantMigrationAccessBlockerForDbPrefix(
migrationConflictInfo->getDatabasePrefix())) {
replyBuilder->getBodyBuilder().resetToEmpty();
mtab->checkIfCanWriteOrBlock(opCtx);
}
}
}
} // namespace tenant_migration_donor
} // namespace mongo
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