summaryrefslogtreecommitdiff
path: root/src/mongo/db/sessions_collection.h
blob: e10b493b33288166c2dc174cc1b4d9df486ad2f7 (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
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/**
 *    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 <functional>

#include "mongo/db/logical_session_id.h"

namespace mongo {

class DBClientBase;
class OperationContext;

/**
 * An abstract interface describing the entrypoint into the sessions collection.
 *
 * Different server deployments (standalone, replica set, sharded cluster) should
 * implement their own classes that fulfill this interface.
 */
class SessionsCollection {
public:
    static constexpr StringData kSessionsTTLIndex = "lsidTTLIndex"_sd;

    virtual ~SessionsCollection();

    /**
     * Ensures that the sessions collection exists and has the proper indexes. Implementations of
     * this method must support multiple concurrent invocations.
     */
    virtual void setupSessionsCollection(OperationContext* opCtx) = 0;

    /**
     * Checks if the sessions collection exists and has the proper indexes.
     */
    virtual void checkSessionsCollectionExists(OperationContext* opCtx) = 0;

    /**
     * Updates the last-use times on the given sessions to be greater than or equal to the given
     * time. Throws an exception if a networking issue occurred.
     */
    virtual void refreshSessions(OperationContext* opCtx,
                                 const LogicalSessionRecordSet& sessions) = 0;

    /**
     * Removes the authoritative records for the specified sessions.
     *
     * Implementations should perform authentication checks to ensure that session records may only
     * be removed if their owner is logged in.
     *
     * Throws an exception if the removal fails, for example from a network error.
     */
    virtual void removeRecords(OperationContext* opCtx, const LogicalSessionIdSet& sessions) = 0;

    /**
     * Checks a set of lsids and returns the set that no longer exists.
     *
     * Throws an exception if the fetch cannot occur, for example from a network error.
     */
    virtual LogicalSessionIdSet findRemovedSessions(OperationContext* opCtx,
                                                    const LogicalSessionIdSet& sessions) = 0;

    /**
     * Generates a createIndexes command for the sessions collection TTL index.
     */
    static BSONObj generateCreateIndexesCmd();

    /*
     * Generates a collMod command for the sessions collection TTL index.
     */
    static BSONObj generateCollModCmd();

protected:
    SessionsCollection();

    using SendBatchFn = std::function<void(BSONObj batch)>;
    static SendBatchFn makeSendFnForCommand(const NamespaceString& ns, DBClientBase* client);
    static SendBatchFn makeSendFnForBatchWrite(const NamespaceString& ns, DBClientBase* client);

    using FindBatchFn = std::function<BSONObj(BSONObj batch)>;
    static FindBatchFn makeFindFnForCommand(const NamespaceString& ns, DBClientBase* client);

    /**
     * Formats and sends batches of refreshes for the given set of sessions.
     */
    void _doRefresh(const NamespaceString& ns,
                    const std::vector<LogicalSessionRecord>& sessions,
                    SendBatchFn send);

    /**
     * Formats and sends batches of deletes for the given set of sessions.
     */
    void _doRemove(const NamespaceString& ns,
                   const std::vector<LogicalSessionId>& sessions,
                   SendBatchFn send);

    /**
     * Returns those lsids from the input 'sessions' array which are not present in the sessions
     * collection (essentially performs an inner join of 'sessions' against the sessions
     * collection).
     */
    LogicalSessionIdSet _doFindRemoved(const NamespaceString& ns,
                                       const std::vector<LogicalSessionId>& sessions,
                                       FindBatchFn send);
};

}  // namespace mongo