1
2 /**
3 * Copyright (C) 2018-present MongoDB, Inc.
4 *
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the Server Side Public License, version 1,
7 * as published by MongoDB, Inc.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * Server Side Public License for more details.
13 *
14 * You should have received a copy of the Server Side Public License
15 * along with this program. If not, see
16 * <http://www.mongodb.com/licensing/server-side-public-license>.
17 *
18 * As a special exception, the copyright holders give permission to link the
19 * code of portions of this program with the OpenSSL library under certain
20 * conditions as described in each individual source file and distribute
21 * linked combinations including the program with the OpenSSL library. You
22 * must comply with the Server Side Public License in all respects for
23 * all of the code used other than as permitted herein. If you modify file(s)
24 * with this exception, you may extend this exception to your version of the
25 * file(s), but you are not obligated to do so. If you do not wish to do so,
26 * delete this exception statement from your version. If you delete this
27 * exception statement from all source files in the program, then also delete
28 * it in the license file.
29 */
30
31 #include "mongo/platform/basic.h"
32
33 #include "mongo/db/query/plan_cache_indexability.h"
34
35 #include "mongo/base/init.h"
36 #include "mongo/base/owned_pointer_vector.h"
37 #include "mongo/db/matcher/expression.h"
38 #include "mongo/db/matcher/expression_algo.h"
39 #include "mongo/db/matcher/expression_internal_expr_eq.h"
40 #include "mongo/db/matcher/expression_leaf.h"
41 #include "mongo/db/query/collation/collation_index_key.h"
42 #include "mongo/db/query/collation/collator_interface.h"
43 #include "mongo/db/query/index_entry.h"
44 #include "mongo/stdx/memory.h"
45 #include <memory>
46
47 namespace mongo {
48
processSparseIndex(const std::string & indexName,const BSONObj & keyPattern)49 void PlanCacheIndexabilityState::processSparseIndex(const std::string& indexName,
50 const BSONObj& keyPattern) {
51 for (BSONElement elem : keyPattern) {
52 _pathDiscriminatorsMap[elem.fieldNameStringData()][indexName].addDiscriminator(
53 [](const MatchExpression* queryExpr) {
54 if (queryExpr->matchType() == MatchExpression::EQ) {
55 const auto* queryExprEquality =
56 static_cast<const EqualityMatchExpression*>(queryExpr);
57 return !queryExprEquality->getData().isNull();
58 } else if (queryExpr->matchType() == MatchExpression::MATCH_IN) {
59 const auto* queryExprIn = static_cast<const InMatchExpression*>(queryExpr);
60 return !queryExprIn->hasNull();
61 } else {
62 return true;
63 }
64 });
65 }
66 }
67
processPartialIndex(const std::string & indexName,const MatchExpression * filterExpr)68 void PlanCacheIndexabilityState::processPartialIndex(const std::string& indexName,
69 const MatchExpression* filterExpr) {
70 invariant(filterExpr);
71 for (size_t i = 0; i < filterExpr->numChildren(); ++i) {
72 processPartialIndex(indexName, filterExpr->getChild(i));
73 }
74 if (filterExpr->getCategory() != MatchExpression::MatchCategory::kLogical) {
75 _pathDiscriminatorsMap[filterExpr->path()][indexName].addDiscriminator(
76 [filterExpr](const MatchExpression* queryExpr) {
77 return expression::isSubsetOf(queryExpr, filterExpr);
78 });
79 }
80 }
81
processIndexCollation(const std::string & indexName,const BSONObj & keyPattern,const CollatorInterface * collator)82 void PlanCacheIndexabilityState::processIndexCollation(const std::string& indexName,
83 const BSONObj& keyPattern,
84 const CollatorInterface* collator) {
85 for (BSONElement elem : keyPattern) {
86 _pathDiscriminatorsMap[elem.fieldNameStringData()][indexName].addDiscriminator([collator](
87 const MatchExpression* queryExpr) {
88 if (const auto* queryExprComparison =
89 dynamic_cast<const ComparisonMatchExpressionBase*>(queryExpr)) {
90 const bool collatorsMatch =
91 CollatorInterface::collatorsMatch(queryExprComparison->getCollator(), collator);
92 const bool isCollatableType =
93 CollationIndexKey::isCollatableType(queryExprComparison->getData().type());
94 return collatorsMatch || !isCollatableType;
95 }
96
97 if (queryExpr->matchType() == MatchExpression::MATCH_IN) {
98 const auto* queryExprIn = static_cast<const InMatchExpression*>(queryExpr);
99 if (CollatorInterface::collatorsMatch(queryExprIn->getCollator(), collator)) {
100 return true;
101 }
102 for (const auto& equality : queryExprIn->getEqualities()) {
103 if (CollationIndexKey::isCollatableType(equality.type())) {
104 return false;
105 }
106 }
107 return true;
108 }
109
110 // The predicate never compares strings so it is not affected by collation.
111 return true;
112 });
113 }
114 }
115
116 namespace {
117 const IndexToDiscriminatorMap emptyDiscriminators{};
118 } // namespace
119
getDiscriminators(StringData path) const120 const IndexToDiscriminatorMap& PlanCacheIndexabilityState::getDiscriminators(
121 StringData path) const {
122 PathDiscriminatorsMap::const_iterator it = _pathDiscriminatorsMap.find(path);
123 if (it == _pathDiscriminatorsMap.end()) {
124 return emptyDiscriminators;
125 }
126 return it->second;
127 }
128
updateDiscriminators(const std::vector<IndexEntry> & indexEntries)129 void PlanCacheIndexabilityState::updateDiscriminators(const std::vector<IndexEntry>& indexEntries) {
130 _pathDiscriminatorsMap = PathDiscriminatorsMap();
131
132 for (const IndexEntry& idx : indexEntries) {
133 if (idx.sparse) {
134 processSparseIndex(idx.name, idx.keyPattern);
135 }
136 if (idx.filterExpr) {
137 processPartialIndex(idx.name, idx.filterExpr);
138 }
139 processIndexCollation(idx.name, idx.keyPattern, idx.collator);
140 }
141 }
142
143 } // namespace mongo
144