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
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
|
/**
* 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/cst/c_node.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/matcher/expression.h"
#include "mongo/db/matcher/extensions_callback_noop.h"
#include "mongo/db/pipeline/inner_pipeline_stage_interface.h"
#include "mongo/db/query/collation/collator_interface.h"
#include "mongo/db/query/projection.h"
#include "mongo/db/query/projection_policies.h"
#include "mongo/db/query/query_request_helper.h"
#include "mongo/db/query/sort_pattern.h"
namespace mongo {
class OperationContext;
class CanonicalQuery {
public:
// A type that encodes the notion of query shape suitable for use with the plan cache. Encodes
// the query's match, projection, sort, etc. potentially with some constants removed or replaced
// with parameter markers.
typedef std::string QueryShapeString;
// A second encoding of query shape similar to 'QueryShapeString' above, except designed to work
// with index filters rather than the plan cache key. A caller can encode a query into an
// 'IndexFilterKey' in order to look for matching index filters that should apply to the query.
typedef std::string IndexFilterKey;
/**
* If parsing succeeds, returns a std::unique_ptr<CanonicalQuery> representing the parsed
* query (which will never be NULL). If parsing fails, returns an error Status.
*
* 'opCtx' must point to a valid OperationContext, but 'opCtx' does not need to outlive the
* returned CanonicalQuery.
*/
static StatusWith<std::unique_ptr<CanonicalQuery>> canonicalize(
OperationContext* opCtx,
std::unique_ptr<FindCommandRequest> findCommand,
bool explain = false,
const boost::intrusive_ptr<ExpressionContext>& expCtx = nullptr,
const ExtensionsCallback& extensionsCallback = ExtensionsCallbackNoop(),
MatchExpressionParser::AllowedFeatureSet allowedFeatures =
MatchExpressionParser::kDefaultSpecialFeatures,
const ProjectionPolicies& projectionPolicies = ProjectionPolicies::findProjectionPolicies(),
std::vector<std::unique_ptr<InnerPipelineStageInterface>> pipeline = {});
/**
* For testing or for internal clients to use.
*/
/**
* Used for creating sub-queries from an existing CanonicalQuery.
*
* 'root' must be an expression in baseQuery.root().
*
* Does not take ownership of 'root'.
*/
static StatusWith<std::unique_ptr<CanonicalQuery>> canonicalize(OperationContext* opCtx,
const CanonicalQuery& baseQuery,
MatchExpression* root);
/**
* Returns true if "query" describes an exact-match query on _id.
*/
static bool isSimpleIdQuery(const BSONObj& query);
/**
* Validates the match expression 'root' as well as the query specified by 'request', checking
* for illegal combinations of operators. Returns a non-OK status if any such illegal
* combination is found.
*
* This method can be called both on normalized and non-normalized 'root'. However, some checks
* can only be performed once the match expressions is normalized. To perform these checks one
* can call 'isValidNormalized()'.
*
* On success, returns a bitset indicating which types of metadata are *unavailable*. For
* example, if 'root' does not contain a $text predicate, then the returned metadata bitset will
* indicate that text score metadata is unavailable. This means that if subsequent
* $meta:"textScore" expressions are found during analysis of the query, we should raise in an
* error.
*/
static StatusWith<QueryMetadataBitSet> isValid(const MatchExpression* root,
const FindCommandRequest& findCommand);
/**
* Perform additional validation checks on the normalized 'root'.
*/
static Status isValidNormalized(const MatchExpression* root);
const NamespaceString nss() const {
invariant(_findCommand->getNamespaceOrUUID().nss());
return *_findCommand->getNamespaceOrUUID().nss();
}
const std::string ns() const {
return nss().ns();
}
//
// Accessors for the query
//
MatchExpression* root() const {
return _root.get();
}
const BSONObj& getQueryObj() const {
return _findCommand->getFilter();
}
const FindCommandRequest& getFindCommandRequest() const {
return *_findCommand;
}
/**
* Returns the projection, or nullptr if none.
*/
const projection_ast::Projection* getProj() const {
return _proj.get_ptr();
}
projection_ast::Projection* getProj() {
return _proj.get_ptr();
}
const boost::optional<SortPattern>& getSortPattern() const {
return _sortPattern;
}
const CollatorInterface* getCollator() const {
return _expCtx->getCollator();
}
/**
* Returns a bitset indicating what metadata has been requested in the query.
*/
const QueryMetadataBitSet& metadataDeps() const {
return _metadataDeps;
}
/**
* Allows callers to request metadata in addition to that needed as part of the query.
*/
void requestAdditionalMetadata(const QueryMetadataBitSet& additionalDeps) {
_metadataDeps |= additionalDeps;
}
/**
* Compute the "shape" of this query by encoding the match, projection and sort, and stripping
* out the appropriate values. Note that different types of PlanCache use different encoding
* approaches.
*/
QueryShapeString encodeKey() const;
/**
* Encode a shape string for the query suitable for matching the query against the set of
* pre-defined index filters. Similar to 'encodeKey()' above, but intended for use with index
* filters rather than the plan cache.
*/
IndexFilterKey encodeKeyForIndexFilters() const;
/**
* Sets this CanonicalQuery's collator, and sets the collator on this CanonicalQuery's match
* expression tree.
*
* This setter can be used to override the collator that was created from the query request
* during CanonicalQuery construction.
*/
void setCollator(std::unique_ptr<CollatorInterface> collator);
// Debugging
std::string toString() const;
std::string toStringShort() const;
/**
* Returns a count of 'type' nodes in expression tree.
*/
static size_t countNodes(const MatchExpression* root, MatchExpression::MatchType type);
/**
* Returns true if this canonical query may have converted extensions such as $where and $text
* into no-ops during parsing. This will be the case if it allowed $where and $text in parsing,
* but parsed using an ExtensionsCallbackNoop. This does not guarantee that a $where or $text
* existed in the query.
*
* Queries with a no-op extension context are special because they can be parsed and planned,
* but they cannot be executed.
*/
bool canHaveNoopMatchNodes() const {
return _canHaveNoopMatchNodes;
}
bool getExplain() const {
return _explain;
}
bool getForceClassicEngine() const {
return _forceClassicEngine;
}
void setSbeCompatible(bool sbeCompatible) {
_sbeCompatible = sbeCompatible;
}
bool isSbeCompatible() const {
return _sbeCompatible;
}
bool isParameterized() const {
return !_inputParamIdToExpressionMap.empty();
}
const std::vector<const MatchExpression*>& getInputParamIdToMatchExpressionMap() const {
return _inputParamIdToExpressionMap;
}
void setExplain(bool explain) {
_explain = explain;
}
OperationContext* getOpCtx() const {
tassert(6508300, "'CanonicalQuery' does not have an 'ExpressionContext'", _expCtx);
return _expCtx->opCtx;
}
auto& getExpCtx() const {
return _expCtx;
}
auto getExpCtxRaw() const {
return _expCtx.get();
}
void setPipeline(std::vector<std::unique_ptr<InnerPipelineStageInterface>> pipeline) {
_pipeline = std::move(pipeline);
}
const std::vector<std::unique_ptr<InnerPipelineStageInterface>>& pipeline() const {
return _pipeline;
}
private:
// You must go through canonicalize to create a CanonicalQuery.
CanonicalQuery() {}
Status init(OperationContext* opCtx,
boost::intrusive_ptr<ExpressionContext> expCtx,
std::unique_ptr<FindCommandRequest> findCommand,
bool canHaveNoopMatchNodes,
std::unique_ptr<MatchExpression> root,
const ProjectionPolicies& projectionPolicies,
std::vector<std::unique_ptr<InnerPipelineStageInterface>> pipeline);
// Initializes '_sortPattern', adding any metadata dependencies implied by the sort.
//
// Throws a UserException if the sort is illegal, or if any metadata type in
// 'unavailableMetadata' is required.
void initSortPattern(QueryMetadataBitSet unavailableMetadata);
boost::intrusive_ptr<ExpressionContext> _expCtx;
std::unique_ptr<FindCommandRequest> _findCommand;
std::unique_ptr<MatchExpression> _root;
boost::optional<projection_ast::Projection> _proj;
boost::optional<SortPattern> _sortPattern;
std::vector<std::unique_ptr<InnerPipelineStageInterface>> _pipeline;
// Keeps track of what metadata has been explicitly requested.
QueryMetadataBitSet _metadataDeps;
bool _canHaveNoopMatchNodes = false;
bool _explain = false;
// Determines whether the classic engine must be used.
bool _forceClassicEngine = true;
// True if this query can be executed by the SBE.
bool _sbeCompatible = false;
// A map from assigned InputParamId's to parameterised MatchExpression's.
std::vector<const MatchExpression*> _inputParamIdToExpressionMap;
};
} // namespace mongo
|