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/**
* Copyright (C) 2013 10gen 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 <string>
#include "mongo/base/status.h"
#include "mongo/db/hasher.h" // For HashSeed.
#include "mongo/db/index/index_descriptor.h"
#include "mongo/db/index/index_access_method.h"
#include "mongo/db/jsobj.h"
namespace mongo {
/**
* This is the access method for "hashed" indices.
*/
class HashAccessMethod : public IndexAccessMethod {
public:
HashAccessMethod(IndexCatalogEntry* btreeState, SortedDataInterface* btree);
private:
/**
* Fills 'keys' with the keys that should be generated for 'obj' on this index.
*
* This function ignores the 'multikeyPaths' pointer because hashed indexes don't support
* tracking path-level multikey information.
*/
void getKeys(const BSONObj& obj, BSONObjSet* keys, MultikeyPaths* multikeyPaths) const final;
// Only one of our fields is hashed. This is the field name for it.
std::string _hashedField;
// _seed defaults to zero.
HashSeed _seed;
// _hashVersion defaults to zero.
int _hashVersion;
BSONObj _missingKey;
// Null if this index orders strings according to the simple binary compare. If non-null,
// represents the collator used to generate index keys for indexed strings.
const CollatorInterface* _collator;
};
} // namespace mongo
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