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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 <memory>
#include "mongo/db/catalog/health_log_gen.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/query/plan_executor.h"
#include "mongo/db/repl/dbcheck_gen.h"
#include "mongo/util/md5.hpp"
namespace mongo {
// Forward declarations.
class Collection;
class OperationContext;
namespace repl {
class OpTime;
}
/**
* Get an error message if the check fails.
*/
std::unique_ptr<HealthLogEntry> dbCheckErrorHealthLogEntry(const NamespaceString& nss,
const std::string& msg,
OplogEntriesEnum operation,
const Status& err);
/**
* Get a HealthLogEntry for a dbCheck batch.
*/
std::unique_ptr<HealthLogEntry> dbCheckBatchEntry(const NamespaceString& nss,
int64_t count,
int64_t bytes,
const std::string& expectedHash,
const std::string& foundHash,
const BSONKey& minKey,
const BSONKey& maxKey,
const repl::OpTime& optime);
/**
* The collection metadata dbCheck sends between nodes.
*/
struct DbCheckCollectionInformation {
std::string collectionName;
boost::optional<UUID> prev;
boost::optional<UUID> next;
std::vector<BSONObj> indexes;
BSONObj options;
};
/**
* Returns a pair of previous and next UUIDs around the given collections uuid. If there is no
* previous or next UUID, return boost::none respectively.
*/
std::pair<boost::optional<UUID>, boost::optional<UUID>> getPrevAndNextUUIDs(OperationContext* opCtx,
Collection* collection);
/**
* Get a HealthLogEntry for a dbCheck collection.
*/
std::unique_ptr<HealthLogEntry> dbCheckCollectionEntry(const NamespaceString& nss,
const UUID& uuid,
const DbCheckCollectionInformation& expected,
const DbCheckCollectionInformation& found,
const repl::OpTime& optime);
/**
* Hashing collections and plans.
*
* Provides MD5-based hashing of ranges of documents. Note that this class does *not* provide
* synchronization: clients must, for example, lock the database to ensure that named collections
* exist, and hold at least a MODE_IS lock before asking a `DbCheckHasher` to retrieve any
* documents.
*/
class DbCheckHasher {
public:
/**
* Create a new DbCheckHasher hashing documents within the given limits.
*
* The check will end when any of the specified limits are reached. Must be called on a
* collection with an _id index; otherwise a DBException with code ErrorCodes::IndexNotFound
* will be thrown.
*
* @param collection The collection to hash from.
* @param start The first key to hash (exclusive).
* @param end The last key to hash (inclusive).
* @param maxCount The maximum number of documents to hash.
* @param maxBytes The maximum number of bytes to hash.
*/
DbCheckHasher(OperationContext* opCtx,
Collection* collection,
const BSONKey& start,
const BSONKey& end,
int64_t maxCount = std::numeric_limits<int64_t>::max(),
int64_t maxBytes = std::numeric_limits<int64_t>::max());
/**
* Hash all of our documents.
*/
Status hashAll(void);
/**
* Return the total hash of all documents seen so far.
*/
std::string total(void);
/**
* Get the last key this hasher has hashed.
*
* Again, not the same as the `end` passed in; this is MinKey if no documents have been hashed.
*/
BSONKey lastKey(void) const;
int64_t bytesSeen(void) const;
int64_t docsSeen(void) const;
private:
/**
* Can we hash `obj` without going over our limits?
*/
bool _canHash(const BSONObj& obj);
OperationContext* _opCtx;
std::unique_ptr<PlanExecutor, PlanExecutor::Deleter> _exec;
md5_state_t _state;
BSONKey _maxKey;
BSONKey _last = BSONKey::min();
int64_t _maxCount = 0;
int64_t _countSeen = 0;
int64_t _maxBytes = 0;
int64_t _bytesSeen = 0;
};
/**
* Get the given database in MODE_S, while also blocking stepdown (SERVER-28544) and allowing writes
* to "local".
*/
class AutoGetDbForDbCheck {
public:
AutoGetDbForDbCheck(OperationContext* opCtx, const NamespaceString& nss);
Database* getDb(void) {
return agd.getDb();
}
private:
Lock::DBLock localLock;
AutoGetDb agd;
};
/**
* Get the given collection in MODE_S, except that if the collection is missing it will report that
* to the health log, and it takes an IX lock on "local" as a workaround to SERVER-28544.
*/
class AutoGetCollectionForDbCheck {
public:
AutoGetCollectionForDbCheck(OperationContext* opCtx,
const NamespaceString& nss,
const OplogEntriesEnum& type);
Collection* getCollection(void) {
return _collection;
}
private:
AutoGetDbForDbCheck _agd;
Lock::CollectionLock _collLock;
Collection* _collection;
};
/**
* Gather the index information for a collection.
*/
std::vector<BSONObj> collectionIndexInfo(OperationContext* opCtx, Collection* collection);
/**
* Gather other information for a collection.
*/
BSONObj collectionOptions(OperationContext* opCtx, Collection* collection);
namespace repl {
/**
* Perform the dbCheck oplog command.
*
* Returns a `Status` to match the type used for oplog command hooks, but in fact always handles
* errors (primarily by writing to the health log), so always returns `Status::OK`.
*/
Status dbCheckOplogCommand(OperationContext* opCtx,
const repl::OplogEntry& entry,
OplogApplication::Mode mode);
} // namespace repl
} // namespace mongo
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