summaryrefslogtreecommitdiff
path: root/src/mongo/db/index/haystack_access_method.h
blob: 4bf8fc4183906e699d088a747b1a969db15bab46 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
/**
*    Copyright (C) 2013-2014 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/base/status.h"
#include "mongo/db/index/index_access_method.h"
#include "mongo/db/index/index_descriptor.h"
#include "mongo/db/jsobj.h"

namespace mongo {

class Collection;
class OperationContext;

/**
 * Maps (lat, lng) to the bucketSize-sided square bucket that contains it.
 * Examines all documents in a given radius of a given point.
 * Returns all documents that match a given search restriction.
 * See http://dochub.mongodb.org/core/haystackindexes
 *
 * Use when you want to look for restaurants within 25 miles with a certain name.
 * Don't use when you want to find the closest open restaurants; see 2d.cpp for that.
 *
 * Usage:
 * db.foo.ensureIndex({ pos : "geoHaystack", type : 1 }, { bucketSize : 1 })
 *   pos is the name of the field to be indexed that has lat/lng data in an array.
 *   type is the name of the secondary field to be indexed.
 *   bucketSize specifies the dimension of the square bucket for the data in pos.
 * ALL fields are mandatory.
 */
class HaystackAccessMethod : public IndexAccessMethod {
public:
    HaystackAccessMethod(IndexCatalogEntry* btreeState, SortedDataInterface* btree);

protected:
    friend class GeoHaystackSearchCommand;
    void searchCommand(OperationContext* opCtx,
                       Collection* collection,
                       const BSONObj& nearObj,
                       double maxDistance,
                       const BSONObj& search,
                       BSONObjBuilder* result,
                       unsigned limit);

private:
    /**
     * Fills 'keys' with the keys that should be generated for 'obj' on this index.
     *
     * This function ignores the 'multikeyPaths' pointer because geoHaystack indexes don't support
     * tracking path-level multikey information.
     */
    void doGetKeys(const BSONObj& obj, BSONObjSet* keys, MultikeyPaths* multikeyPaths) const final;

    std::string _geoField;
    std::vector<std::string> _otherFields;
    double _bucketSize;
};

}  // namespace mongo