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// record_data.h
/**
* Copyright (C) 2014 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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/bson/bsonobj.h"
#include "mongo/util/shared_buffer.h"
namespace mongo {
// TODO: Does this need to have move support?
/**
* A replacement for the Record class. This class represents data in a record store.
* The _dataPtr attribute is used to manage memory ownership. If _dataPtr is NULL, then
* the memory pointed to by _data is owned by the RecordStore. If _dataPtr is not NULL, then
* it must point to the same array as _data.
*/
class RecordData {
public:
RecordData() : _data( NULL ), _size( 0 ) {}
RecordData(const char* data, int size): _data(data), _size(size) { }
RecordData(SharedBuffer ownedData, int size)
: _data(ownedData.get()), _size(size), _ownedData(std::move(ownedData)) {
}
const char* data() const { return _data; }
int size() const { return _size; }
/**
* Returns true if this owns its own memory, and false otherwise
*/
bool isOwned() const { return _ownedData.get(); }
SharedBuffer releaseBuffer() {
return std::move(_ownedData);
}
BSONObj toBson() const { return isOwned() ? BSONObj(_ownedData) : BSONObj(_data); }
BSONObj releaseToBson() { return isOwned() ? BSONObj(releaseBuffer()) : BSONObj(_data); }
// TODO uncomment once we require compilers that support overloading for rvalue this.
// BSONObj toBson() && { return releaseToBson(); }
RecordData getOwned() const {
if (isOwned()) return *this;
auto buffer = SharedBuffer::allocate(_size);
memcpy(buffer.get(), _data, _size);
return RecordData(buffer, _size);
}
void makeOwned() {
if (isOwned()) return;
*this = getOwned();
}
private:
const char* _data;
int _size;
SharedBuffer _ownedData;
};
} // namespace mongo
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