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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 <boost/optional.hpp>
#include <string>
#include <vector>
#include "mongo/s/catalog/type_chunk.h"
#include "mongo/s/chunk_version.h"
#include "mongo/s/client/shard.h"
namespace mongo {
class NamespaceString;
class OperationContext;
class ShardKeyPattern;
class ShardRegistry;
template <typename T>
class StatusWith;
/**
* Set of functions used to introspect and manipulate the state of individual shards.
*/
namespace shardutil {
static constexpr size_t kMaxSplitPoints = 8192;
/**
* Executes the listDatabases command against the specified shard and obtains the total data
* size across all databases in bytes (essentially, the totalSize field).
*
* Returns OK with the total size or an error. Known errors are:
* ShardNotFound if shard by that id is not available on the registry
* NoSuchKey if the total shard size could not be retrieved
*/
StatusWith<long long> retrieveTotalShardSize(OperationContext* opCtx, const ShardId& shardId);
/**
* Executes the dataSize command against the specified shard and obtains the total data
* size for the collection in bytes (essentially, the dataSize field).
*
* Returns OK with the total size in bytes or an error. Known errors are:
* ShardNotFound if shard by that id is not available on the registry
* NoSuchKey if the total shard size could not be retrieved
*/
StatusWith<long long> retrieveCollectionShardSize(OperationContext* opCtx,
const ShardId& shardId,
NamespaceString const& ns,
bool estimate = true);
/**
* Ask the specified shard to figure out the split points for a given chunk.
*
* shardId The shard id to query.
* nss Namespace, which owns the chunk.
* shardKeyPattern The shard key which corresponds to this sharded namespace.
* chunkRange Bounds of the chunk to be split.
* chunkSize Chunk size to target in bytes.
* maxObjs Limits the number of objects in each chunk. Zero means max, unspecified means use the
* server default.
*/
StatusWith<std::vector<BSONObj>> selectChunkSplitPoints(OperationContext* opCtx,
const ShardId& shardId,
const NamespaceString& nss,
const ShardKeyPattern& shardKeyPattern,
const ChunkRange& chunkRange,
long long chunkSizeBytes);
/**
* Asks the specified shard to split the chunk described by min/maxKey into the respective split
* points. If split was successful and the shard indicated that one of the resulting chunks should
* be moved off the currently owning shard, the return value will contain the bounds of this chunk.
*
* shardId The shard, which currently owns the chunk.
* nss Namespace, which owns the chunk.
* shardKeyPattern The shard key which corresponds to this sharded namespace.
* collectionVersion The expected collection version when doing the split.
* chunkRange Bounds of the chunk to be split.
* splitPoints The set of points at which the chunk should be split.
*/
StatusWith<boost::optional<ChunkRange>> splitChunkAtMultiplePoints(
OperationContext* opCtx,
const ShardId& shardId,
const NamespaceString& nss,
const ShardKeyPattern& shardKeyPattern,
const OID& epoch,
const Timestamp& timestamp,
ChunkVersion shardVersion,
const ChunkRange& chunkRange,
const std::vector<BSONObj>& splitPoints);
} // namespace shardutil
} // namespace mongo
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