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
|
/**
* 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.
*/
#include "mongo/platform/basic.h"
#include "mongo/base/string_data.h"
#include "mongo/bson/bson_depth.h"
#include "mongo/db/pipeline/field_path.h"
#include "mongo/db/query/query_feature_flags_gen.h"
#include "mongo/db/query/query_knobs_gen.h"
#include "mongo/db/server_options.h"
#include "mongo/util/str.h"
#include "mongo/util/string_map.h"
namespace mongo {
namespace {
const StringDataSet kAllowedDollarPrefixedFields = {
// For DBRef
"$id"_sd,
"$ref"_sd,
"$db"_sd,
// Metadata fields.
// This is necessary for sharded query execution of find() commands. mongos may attach a
// $sortKey field to the projection sent to shards so that it can merge the results correctly.
"$sortKey",
// This is necessary for the "showRecordId" feature.
"$recordId"};
} // namespace
using std::string;
using std::vector;
string FieldPath::getFullyQualifiedPath(StringData prefix, StringData suffix) {
if (prefix.empty()) {
return suffix.toString();
}
return str::stream() << prefix << "." << suffix;
}
FieldPath::FieldPath(std::string inputPath)
: _fieldPath(std::move(inputPath)),
_fieldPathDotPosition{string::npos},
_fieldHash{kHashUninitialized} {
uassert(40352, "FieldPath cannot be constructed with empty string", !_fieldPath.empty());
uassert(40353, "FieldPath must not end with a '.'.", _fieldPath[_fieldPath.size() - 1] != '.');
// Store index delimiter position for use in field lookup.
size_t dotPos;
size_t startPos = 0;
while (string::npos != (dotPos = _fieldPath.find('.', startPos))) {
_fieldPathDotPosition.push_back(dotPos);
_fieldHash.push_back(kHashUninitialized);
startPos = dotPos + 1;
}
_fieldPathDotPosition.push_back(_fieldPath.size());
// Validate the path length and the fields.
const auto pathLength = getPathLength();
uassert(ErrorCodes::Overflow,
"FieldPath is too long",
pathLength <= BSONDepth::getMaxAllowableDepth());
for (size_t i = 0; i < pathLength; ++i) {
uassertValidFieldName(getFieldName(i));
}
}
void FieldPath::uassertValidFieldName(StringData fieldName) {
uassert(15998, "FieldPath field names may not be empty strings.", !fieldName.empty());
const auto dotsAndDollarsHint = " Consider using $getField or $setField.";
if (fieldName[0] == '$' && !kAllowedDollarPrefixedFields.count(fieldName)) {
uasserted(16410,
str::stream() << "FieldPath field names may not start with '$'."
<< dotsAndDollarsHint);
}
uassert(
16411, "FieldPath field names may not contain '\0'.", fieldName.find('\0') == string::npos);
uassert(16412,
str::stream() << "FieldPath field names may not contain '.'." << dotsAndDollarsHint,
fieldName.find('.') == string::npos);
}
FieldPath FieldPath::concat(const FieldPath& tail) const {
const FieldPath& head = *this;
std::string concat;
uassert(ErrorCodes::Overflow,
"FieldPath concat would be too long",
getPathLength() + tail.getPathLength() <= BSONDepth::getMaxAllowableDepth());
const auto expectedStringSize = _fieldPath.size() + 1 + tail._fieldPath.size();
concat.reserve(expectedStringSize);
concat.insert(concat.begin(), head._fieldPath.begin(), head._fieldPath.end());
concat.push_back('.');
concat.insert(concat.end(), tail._fieldPath.begin(), tail._fieldPath.end());
invariant(concat.size() == expectedStringSize);
std::vector<size_t> newDots;
// Subtract 2 since both contain std::string::npos at the beginning and the entire size at
// the end. Add one because we inserted a dot in order to concatenate the two paths.
const auto expectedDotSize =
head._fieldPathDotPosition.size() + tail._fieldPathDotPosition.size() - 2 + 1;
newDots.reserve(expectedDotSize);
std::vector<size_t> newHashes;
// We don't need the extra entry in hashes.
newHashes.reserve(expectedDotSize - 1);
// The first one in head._fieldPathDotPosition is npos. The last one, is, conveniently, the
// size of head fieldPath, which also happens to be the index at which we added a new dot.
newDots.insert(
newDots.begin(), head._fieldPathDotPosition.begin(), head._fieldPathDotPosition.end());
newHashes.insert(newHashes.begin(), head._fieldHash.begin(), head._fieldHash.end());
invariant(tail._fieldPathDotPosition.size() >= 2);
for (size_t i = 1; i < tail._fieldPathDotPosition.size(); ++i) {
// Move each index back by size of the first field path, plus one, for the newly added dot.
newDots.push_back(tail._fieldPathDotPosition[i] + head._fieldPath.size() + 1);
newHashes.push_back(tail._fieldHash[i - 1]);
}
invariant(newDots.back() == concat.size());
invariant(newDots.size() == expectedDotSize);
invariant(newHashes.size() == expectedDotSize - 1);
return FieldPath(std::move(concat), std::move(newDots), std::move(newHashes));
}
} // namespace mongo
|
