summaryrefslogtreecommitdiff
path: root/src/mongo/bson/mutable/const_element.h
blob: 902ea7b772bd144227a36cbed05a7025bb56a557 (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

/**
 *    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/bson/mutable/element.h"

namespace mongo {
namespace mutablebson {

/** For an overview of mutable BSON, please see the file document.h in this directory. */

/** ConstElement recapitulates all of the const methods of Element, but cannot be converted
 *  to an Element. This makes it safe to return as a value from a constant Document, since
 *  none of Element's non-const methods may be called on ConstElement or any values it
 *  yields. If you think of Element like an STL 'iterator', then ConstElement is a
 *  'const_iterator'.
 *
 *  For details on the API methods of ConstElement, please see the method comments for the
 *  analagous Element methods in the file element.h (in this same directory).
 *
 *  All calls on ConstElement are simply forwarded to the underlying Element.
 */
class ConstElement {
public:
    // This one argument constructor is intentionally not explicit, since we want to be
    // able to pass Elements to functions taking ConstElements without complaint.
    inline ConstElement(const Element& basis);

    inline ConstElement leftChild() const;
    inline ConstElement rightChild() const;
    inline bool hasChildren() const;
    inline ConstElement leftSibling(size_t distance = 1) const;
    inline ConstElement rightSibling(size_t distance = 1) const;
    inline ConstElement parent() const;
    inline ConstElement findNthChild(size_t n) const;
    inline ConstElement operator[](size_t n) const;
    inline ConstElement findFirstChildNamed(StringData name) const;
    inline ConstElement operator[](StringData n) const;
    inline ConstElement findElementNamed(StringData name) const;

    inline size_t countSiblingsLeft() const;
    inline size_t countSiblingsRight() const;
    inline size_t countChildren() const;

    inline bool hasValue() const;
    inline const BSONElement getValue() const;

    inline double getValueDouble() const;
    inline StringData getValueString() const;
    inline BSONObj getValueObject() const;
    inline BSONArray getValueArray() const;
    inline bool isValueUndefined() const;
    inline OID getValueOID() const;
    inline bool getValueBool() const;
    inline Date_t getValueDate() const;
    inline bool isValueNull() const;
    inline StringData getValueSymbol() const;
    inline int32_t getValueInt() const;
    inline Timestamp getValueTimestamp() const;
    inline int64_t getValueLong() const;
    inline Decimal128 getValueDecimal() const;
    inline bool isValueMinKey() const;
    inline bool isValueMaxKey() const;
    inline SafeNum getValueSafeNum() const;

    inline int compareWithElement(const ConstElement& other,
                                  const StringData::ComparatorInterface* comparator,
                                  bool considerFieldName = true) const;

    inline int compareWithBSONElement(const BSONElement& other,
                                      const StringData::ComparatorInterface* comparator,
                                      bool considerFieldName = true) const;

    inline int compareWithBSONObj(const BSONObj& other,
                                  const StringData::ComparatorInterface* comparator,
                                  bool considerFieldName = true) const;

    inline void writeTo(BSONObjBuilder* builder) const;
    inline void writeArrayTo(BSONArrayBuilder* builder) const;

    inline bool ok() const;
    inline const Document& getDocument() const;
    inline BSONType getType() const;
    inline bool isType(BSONType type) const;
    inline StringData getFieldName() const;
    inline Element::RepIdx getIdx() const;

    inline std::string toString() const;

    friend bool operator==(const ConstElement&, const ConstElement&);

private:
    friend class Document;

    template <typename Builder>
    inline void writeElement(Builder* builder, const StringData* fieldName = NULL) const;

    Element _basis;
};

/** See notes for operator==(const Element&, const Element&). The multiple variants listed
 *  here enable cross type comparisons between Elements and ConstElements.
 */
inline bool operator==(const ConstElement& l, const ConstElement& r);
inline bool operator!=(const ConstElement& l, const ConstElement& r);
inline bool operator==(const Element& l, const ConstElement& r);
inline bool operator!=(const Element& l, const ConstElement& r);
inline bool operator==(const ConstElement& l, const Element& r);
inline bool operator!=(const ConstElement& l, const Element& r);

}  // namespace mutablebson
}  // namespace mongo

#include "mongo/bson/mutable/const_element-inl.h"