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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
/**
* 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 <set>
#include <string>
#include "mongo/db/exec/projection_exec_agg.h"
#include "mongo/db/field_ref.h"
#include "mongo/db/index/multikey_paths.h"
#include "mongo/db/index_names.h"
#include "mongo/db/jsobj.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
class CollatorInterface;
class MatchExpression;
/**
* A CoreIndexInfo is a representation of an index in the catalog with parsed information which is
* used for updating indexability discriminators. Its lifetime is not tied to the underlying
* collection. It is a subset of IndexEntry and is missing fields that are expensive or unavailable.
*/
struct CoreIndexInfo {
struct Identifier;
CoreIndexInfo(const BSONObj& kp,
IndexType type,
bool sp,
Identifier ident,
const MatchExpression* fe = nullptr,
const CollatorInterface* ci = nullptr,
const ProjectionExecAgg* projExec = nullptr)
: identifier(std::move(ident)),
keyPattern(kp),
filterExpr(fe),
type(type),
sparse(sp),
collator(ci),
wildcardProjection(projExec) {
// We always expect a projection executor for $** indexes, and none otherwise.
invariant((type == IndexType::INDEX_WILDCARD) == (projExec != nullptr));
}
/**
* This struct is used to uniquely identify an index. The index "Identifier" has two
* components: catalog name, and "disambiguator". The catalog name is just the name of the
* index in the catalog. The disambiguator is used by the planner when multiple IndexEntries
* may refer to the same underlying index in the catalog. This can only happen with $**
* indices. Otherwise, the disambiguator should be empty.
*
* Has the same comparison and equality semantics as std::pair<string, string>.
*
*/
struct Identifier {
explicit Identifier(std::string aCatalogName) : catalogName(std::move(aCatalogName)) {}
Identifier(std::string aCatalogName, std::string nameDisambiguator)
: catalogName(std::move(aCatalogName)), disambiguator(std::move(nameDisambiguator)) {}
bool operator==(const Identifier& other) const {
return other.catalogName == catalogName && other.disambiguator == disambiguator;
}
bool operator!=(const Identifier& other) const {
return !(*this == other);
}
bool operator<(const Identifier& other) const {
const auto cmpRes = catalogName.compare(other.catalogName);
if (cmpRes != 0) {
return cmpRes < 0;
}
return disambiguator < other.disambiguator;
}
std::string toString() const {
return "(" + catalogName + ", " + disambiguator + ")";
}
// The name of the index in the catalog.
std::string catalogName;
// A string used for disambiguating multiple IndexEntries with the same catalogName (such
// as in the case with a wildcard index).
std::string disambiguator;
} identifier;
BSONObj keyPattern;
const MatchExpression* filterExpr;
// What type of index is this? (What access method can we use on the index described by the
// keyPattern?)
IndexType type;
bool sparse;
// Null if this index orders strings according to the simple binary compare. If non-null,
// represents the collator used to generate index keys for indexed strings.
const CollatorInterface* collator = nullptr;
// For $** indexes, a pointer to the projection executor owned by the index access method. Null
// unless this IndexEntry represents a wildcard index, in which case this is always non-null.
const ProjectionExecAgg* wildcardProjection = nullptr;
};
/**
* An IndexEntry is a representation of an index in the catalog with parsed information which is
* helpful for query planning. Its lifetime is not tied to the underlying collection. In contrast
* to CoreIndexInfo, it includes information such as 'multikeyPaths' which can require resources to
* compute (i.e. for wildcard indexes, this requires reading the index) and so may not always be
* available.
*/
struct IndexEntry : CoreIndexInfo {
IndexEntry(const BSONObj& kp,
IndexType type,
bool mk,
const MultikeyPaths& mkp,
std::set<FieldRef> multikeyPathSet,
bool sp,
bool unq,
Identifier ident,
const MatchExpression* fe,
const BSONObj& io,
const CollatorInterface* ci,
const ProjectionExecAgg* projExec)
: CoreIndexInfo(kp, type, sp, std::move(ident), fe, ci, projExec),
multikey(mk),
multikeyPaths(mkp),
multikeyPathSet(std::move(multikeyPathSet)),
unique(unq),
infoObj(io) {
// The caller must not supply multikey metadata in two different formats.
invariant(multikeyPaths.empty() || multikeyPathSet.empty());
}
~IndexEntry() {
// An IndexEntry should never have both formats of multikey metadata simultaneously.
invariant(multikeyPaths.empty() || multikeyPathSet.empty());
}
/**
* Returns true if 'indexedField' has any multikey components. For example, returns true if this
* index has a multikey component "a", and 'indexedField' is "a.b". Illegal to call unless
* 'indexedField' is present in this index's key pattern.
*
* For indexes created on older versions we may not have path-level multikey information. In
* these cases we only have a single boolean to track whether any path in the index is multikey.
* If this is the case we defensively return true for any path.
*/
bool pathHasMultikeyComponent(StringData indexedField) const;
bool operator==(const IndexEntry& rhs) const {
// Indexes are logically equal when names are equal.
return this->identifier == rhs.identifier;
}
std::string toString() const;
bool multikey;
// If non-empty, 'multikeyPaths' is a vector with size equal to the number of elements in the
// index key pattern. Each element in the vector is an ordered set of positions (starting at 0)
// into the corresponding indexed field that represent what prefixes of the indexed field cause
// the index to be multikey.
//
// An IndexEntry may either represent multikey metadata as a fixed-size MultikeyPaths vector, or
// as an arbitrarily large set of field refs, but not both. That is, either 'multikeyPaths' or
// 'multikeyPathSet' must be empty.
MultikeyPaths multikeyPaths;
// A set of multikey paths. Used instead of 'multikeyPaths' when there could be arbitrarily many
// multikey paths associated with this index entry.
//
// An IndexEntry may either represent multikey metadata as a fixed-size MultikeyPaths vector, or
// as an arbitrarily large set of field refs, but not both. That is, either 'multikeyPaths' or
// 'multikeyPathSet' must be empty.
std::set<FieldRef> multikeyPathSet;
bool unique;
// Geo indices have extra parameters. We need those available to plan correctly.
BSONObj infoObj;
};
std::ostream& operator<<(std::ostream& stream, const IndexEntry::Identifier& ident);
StringBuilder& operator<<(StringBuilder& builder, const IndexEntry::Identifier& ident);
} // namespace mongo
|