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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/namespace_string.h"
#include "mongo/db/s/collection_metadata.h"
#include "mongo/s/database_version.h"
#include "mongo/s/shard_version.h"
namespace mongo {
class OperationContext;
/**
* Must be invoked whenever code, which is executing on a shard encounters a StaleConfig exception
* and should be passed the placement version from the 'version received' in the exception. If the
* shard's current placement version is behind 'chunkVersionReceived', causes the shard's filtering
* metadata to be refreshed from the config server, otherwise does nothing and immediately returns.
* If there are other threads currently performing refresh, blocks so that only one of them hits the
* config server.
*
* If refresh fails for any reason (most commonly ExceededTimeLimit), returns a failed status.
*
* NOTE: Does network I/O and acquires collection lock on the specified namespace, so it must not be
* called with a lock
*
* NOTE: This method is not expected to throw, because it is used in places where StaleConfig
* exception was just caught and if it were to throw, it would overwrite any accumulated command
* execution state in the response. This is specifically problematic for write commands, which are
* expected to return the set of write batch entries that succeeded.
*/
Status onCollectionPlacementVersionMismatchNoExcept(
OperationContext* opCtx,
const NamespaceString& nss,
boost::optional<ChunkVersion> chunkVersionReceived) noexcept;
void onCollectionPlacementVersionMismatch(OperationContext* opCtx,
const NamespaceString& nss,
boost::optional<ChunkVersion> chunkVersionReceived);
/**
* Unconditionally get the shard's filtering metadata from the config server on the calling thread.
* Returns the metadata if the nss is sharded, otherwise default unsharded metadata.
*
* NOTE: Does network I/O, so it must not be called with a lock
*/
CollectionMetadata forceGetCurrentMetadata(OperationContext* opCtx, const NamespaceString& nss);
/**
* Unconditionally causes the shard's filtering metadata to be refreshed from the config server and
* returns the resulting placement version (which might not have changed), or throws.
*
* NOTE: Does network I/O and acquires collection lock on the specified namespace, so it must not be
* called with a lock
*/
ChunkVersion forceShardFilteringMetadataRefresh(OperationContext* opCtx,
const NamespaceString& nss);
/**
* Should be called when any client request on this shard generates a StaleDbVersion exception.
*
* Invalidates the cached database version, schedules a refresh of the database info, waits for the
* refresh to complete, and updates the cached database version.
*/
Status onDbVersionMismatchNoExcept(OperationContext* opCtx,
StringData dbName,
boost::optional<DatabaseVersion> clientDbVersion) noexcept;
} // namespace mongo
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