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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/s/catalog/type_chunk.h"
#include "mongo/s/chunk_version.h"
#include "mongo/s/shard_id.h"
namespace mongo {
class BSONObj;
class ChunkWritesTracker;
/**
* Represents a cache entry for a single Chunk. Owned by a RoutingTableHistory.
*/
class ChunkInfo {
public:
explicit ChunkInfo(const ChunkType& from);
const auto& getRange() const {
return _range;
}
const BSONObj& getMin() const {
return _range.getMin();
}
const BSONObj& getMax() const {
return _range.getMax();
}
const std::string& getMaxKeyString() const {
return _maxKeyString;
}
const ShardId& getShardIdAt(const boost::optional<Timestamp>& ts) const;
/**
* Throws MigrationConflict if the history entry valid for the given timestamp is not the most
* recent entry (meaning the chunk has moved).
*
* Throws StaleChunkHistory if no history entry is valid for the given timestamp.
*/
void throwIfMovedSince(const Timestamp& ts) const;
ChunkVersion getLastmod() const {
return _lastmod;
}
const auto& getHistory() const {
return _history;
}
bool isJumbo() const {
return _jumbo;
}
/**
* Get writes tracker for this chunk.
*/
std::shared_ptr<ChunkWritesTracker> getWritesTracker() const {
return _writesTracker;
}
/**
* Returns a string represenation of the chunk for logging.
*/
std::string toString() const;
// Returns true if this chunk contains the given shard key, and false otherwise
//
// Note: this function takes an extracted *key*, not an original document (the point may be
// computed by, say, hashing a given field or projecting to a subset of fields).
bool containsKey(const BSONObj& shardKey) const;
/**
* Marks this chunk as jumbo. Only moves from false to true once and is used by the balancer.
*/
void markAsJumbo();
private:
const ChunkRange _range;
const std::string _maxKeyString;
const ShardId _shardId;
const ChunkVersion _lastmod;
const std::vector<ChunkHistory> _history;
// Indicates whether this chunk should be treated as jumbo and not attempted to be moved or
// split
mutable bool _jumbo;
// Used for tracking writes to this chunk, to estimate its size for the autosplitter. Since
// ChunkInfo objects are always treated as const, and this contains metadata about the chunk
// that needs to change, it's okay (and necessary) to mark it mutable.
mutable std::shared_ptr<ChunkWritesTracker> _writesTracker;
};
class Chunk {
public:
Chunk(ChunkInfo& chunkInfo, const boost::optional<Timestamp>& atClusterTime)
: _chunkInfo(chunkInfo), _atClusterTime(atClusterTime) {}
const BSONObj& getMin() const {
return _chunkInfo.getMin();
}
const BSONObj& getMax() const {
return _chunkInfo.getMax();
}
const ShardId& getShardId() const {
return _chunkInfo.getShardIdAt(_atClusterTime);
}
const auto& getRange() const {
return _chunkInfo.getRange();
}
/**
* Throws MigrationConflict if the history entry valid for the chunk's pinned cluster time, if
* it has one, is not the most recent entry (meaning the chunk has moved).
*
* Throws StaleChunkHistory if no history entry is valid for the chunk's cluster time.
*/
void throwIfMoved() const;
ChunkVersion getLastmod() const {
return _chunkInfo.getLastmod();
}
const auto& getHistory() const {
return _chunkInfo.getHistory();
}
bool isJumbo() const {
return _chunkInfo.isJumbo();
}
/**
* Get writes tracker for this chunk.
*/
std::shared_ptr<ChunkWritesTracker> getWritesTracker() const {
return _chunkInfo.getWritesTracker();
}
/**
* Returns a string represenation of the chunk for logging.
*/
std::string toString() const {
return _chunkInfo.toString();
}
// Returns true if this chunk contains the given shard key, and false otherwise
//
// Note: this function takes an extracted *key*, not an original document (the point may be
// computed by, say, hashing a given field or projecting to a subset of fields).
bool containsKey(const BSONObj& shardKey) const {
return _chunkInfo.containsKey(shardKey);
}
/**
* Marks this chunk as jumbo. Only moves from false to true once and is used by the balancer.
*/
void markAsJumbo() {
_chunkInfo.markAsJumbo();
}
private:
ChunkInfo& _chunkInfo;
const boost::optional<Timestamp> _atClusterTime;
};
} // namespace mongo
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