summaryrefslogtreecommitdiff
path: root/src/mongo/db/ops/parsed_update.h
blob: 40e3a279712b03ef39c4e13dfd244d3d6ac66b4c (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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/**
 *    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 "mongo/base/status.h"
#include "mongo/db/matcher/expression_with_placeholder.h"
#include "mongo/db/query/collation/collator_interface.h"
#include "mongo/db/query/plan_yield_policy.h"
#include "mongo/db/update/update_driver.h"

namespace mongo {

class CanonicalQuery;
class OperationContext;
class UpdateRequest;

/**
 * This class takes a pointer to an UpdateRequest, and converts that request into a parsed form
 * via the parseRequest() method. A ParsedUpdate can then be used to retrieve a PlanExecutor
 * capable of executing the update.
 *
 * It is invalid to request that the UpdateStage return the prior or newly-updated version of a
 * document during a multi-update. It is also invalid to request that a ProjectionStage be
 * applied to the UpdateStage if the UpdateStage would not return any document.
 *
 * No locks need to be held during parsing.
 *
 * The query part of the update is parsed to a CanonicalQuery, and the update part is parsed
 * using the UpdateDriver.
 */
class ParsedUpdate {
    ParsedUpdate(const ParsedUpdate&) = delete;
    ParsedUpdate& operator=(const ParsedUpdate&) = delete;

public:
    /**
     * Constructs a parsed update.
     *
     * The objects pointed to by "request" and "extensionsCallback" must stay in scope for the life
     * of the constructed ParsedUpdate.
     */
    ParsedUpdate(OperationContext* opCtx,
                 const UpdateRequest* request,
                 const ExtensionsCallback& extensionsCallback,
                 bool forgoOpCounterIncrements = false);

    /**
     * Parses the update request to a canonical query and an update driver. On success, the
     * parsed update can be used to create a PlanExecutor for this update.
     */
    Status parseRequest();

    /**
     * As an optimization, we do not create a canonical query if the predicate is a simple
     * _id equality. This method can be used to force full parsing to a canonical query,
     * as a fallback if the idhack path is not available (e.g. no _id index).
     */
    Status parseQueryToCQ();

    /**
     * Get the raw request.
     */
    const UpdateRequest* getRequest() const;

    /**
     * Get a pointer to the update driver, the abstraction which both parses the update and
     * is capable of applying mods / computing damages.
     */
    UpdateDriver* getDriver();

    /**
     * Get the YieldPolicy, adjusted for GodMode.
     */
    PlanYieldPolicy::YieldPolicy yieldPolicy() const;

    /**
     * As an optimization, we don't create a canonical query for updates with simple _id
     * queries. Use this method to determine whether or not we actually parsed the query.
     */
    bool hasParsedQuery() const;

    /**
     * Returns a const pointer to the canonical query. Requires that hasParsedQuery() is true.
     */
    const CanonicalQuery* getParsedQuery() const {
        invariant(_canonicalQuery);
        return _canonicalQuery.get();
    }

    /**
     * Releases ownership of the canonical query to the caller.
     */
    std::unique_ptr<CanonicalQuery> releaseParsedQuery();

    /**
     * Sets this ParsedUpdate's collator.
     *
     * This setter can be used to override the collator that was created from the update request
     * during ParsedUpdate construction.
     */
    void setCollator(std::unique_ptr<CollatorInterface> collator);

    /**
     * Never returns nullptr.
     */
    boost::intrusive_ptr<ExpressionContext> expCtx() const {
        return _expCtx;
    }

private:
    /**
     * Parses the query portion of the update request.
     */
    Status parseQuery();

    /**
     * Parses the update-descriptor portion of the update request.
     */
    void parseUpdate();

    // Unowned pointer to the transactional context.
    OperationContext* _opCtx;

    // Unowned pointer to the request object to process.
    const UpdateRequest* const _request;

    // The array filters for the parsed update. Owned here.
    std::map<StringData, std::unique_ptr<ExpressionWithPlaceholder>> _arrayFilters;

    boost::intrusive_ptr<ExpressionContext> _expCtx;

    // Driver for processing updates on matched documents.
    UpdateDriver _driver;

    // Parsed query object, or NULL if the query proves to be an id hack query.
    std::unique_ptr<CanonicalQuery> _canonicalQuery;

    // Reference to an extensions callback used when parsing to a canonical query.
    const ExtensionsCallback& _extensionsCallback;
};

}  // namespace mongo