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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/filesystem/path.hpp>
#include <memory>
#include <ostream>
#include <string>
#include "mongo/base/status.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/storage/data_protector.h"
namespace mongo {
/**
* This class provides facility for saving bson objects to a flat file. The common use case is for
* making a back-up copy of a document before an internal operation (like migration or rollback)
* deletes it. To use this correctly, the caller must call goingToDelete first before the actual
* deletion, otherwise the document will be lost if the process gets terminated in between.
*/
class RemoveSaver {
RemoveSaver(const RemoveSaver&) = delete;
RemoveSaver& operator=(const RemoveSaver&) = delete;
public:
class Storage;
RemoveSaver(const std::string& type,
const std::string& ns,
const std::string& why,
std::unique_ptr<Storage> storage = std::make_unique<Storage>());
~RemoveSaver();
/**
* Writes document to file. File is created lazily before writing the first document.
* Returns error status if the file could not be created or if there were errors writing
* to the file.
*/
Status goingToDelete(const BSONObj& o);
/**
* A path object describing the directory containing the file with deleted documents.
*/
const auto& root() const& {
return _root;
}
void root() && = delete;
/**
* A path object describing the actual file containing BSON documents.
*/
const auto& file() const& {
return _file;
}
void file() && = delete;
class Storage {
public:
virtual ~Storage() = default;
virtual std::unique_ptr<std::ostream> makeOstream(const boost::filesystem::path& file,
const boost::filesystem::path& root);
virtual void dumpBuffer() {}
};
private:
boost::filesystem::path _root;
boost::filesystem::path _file;
std::unique_ptr<DataProtector> _protector;
std::unique_ptr<std::ostream> _out;
std::unique_ptr<Storage> _storage;
};
} // namespace mongo
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