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
|
/**
* Copyright (C) 2013 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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/db/jsobj.h"
#include "mongo/db/hasher.h"
#include "mongo/db/matcher/expression_parser.h"
#include "mongo/db/query/index_bounds.h"
#include "mongo/db/query/index_entry.h"
namespace mongo {
/**
* Translates expressions over fields into bounds on an index.
*/
class IndexBoundsBuilder {
public:
enum BoundsTightness {
// Index bounds are exact.
EXACT,
// Index bounds are inexact, and a fetch is required.
INEXACT_FETCH,
// Index bounds are inexact, but no fetch is required
INEXACT_COVERED
};
/**
* Populate the provided O.I.L. with one interval goes from MinKey to MaxKey (or vice-versa
* depending on the index direction).
*/
static void allValuesForField(const BSONElement& elt, OrderedIntervalList* out);
/**
* Turn the MatchExpression in 'expr' into a set of index bounds. The field that 'expr' is
* concerned with is indexed according to the keypattern element 'elt' from index 'index'.
*
* If 'expr' is elemMatch, the index tag is affixed to a child.
*
* The expression must be a predicate over one field. That is, expr->isLeaf() or
* expr->isArray() must be true, and expr->isLogical() must be false.
*/
static void translate(const MatchExpression* expr,
const BSONElement& elt,
const IndexEntry& index,
OrderedIntervalList* oilOut,
BoundsTightness* tightnessOut);
/**
* Creates bounds for 'expr' (indexed according to 'elt'). Intersects those bounds
* with the bounds in oilOut, which is an in/out parameter.
*/
static void translateAndIntersect(const MatchExpression* expr,
const BSONElement& elt,
const IndexEntry& index,
OrderedIntervalList* oilOut,
BoundsTightness* tightnessOut);
/**
* Creates bounds for 'expr' (indexed according to 'elt'). Unions those bounds
* with the bounds in oilOut, which is an in/out parameter.
*/
static void translateAndUnion(const MatchExpression* expr,
const BSONElement& elt,
const IndexEntry& index,
OrderedIntervalList* oilOut,
BoundsTightness* tightnessOut);
/**
* Make a range interval from the provided object.
* The object must have exactly two fields. The first field is the start, the second the
* end.
* The two inclusive flags indicate whether or not the start/end fields are included in the
* interval (closed interval if included, open if not).
*/
static Interval makeRangeInterval(const BSONObj& obj,
bool startInclusive,
bool endInclusive);
static Interval makeRangeInterval(const std::string& start,
const std::string& end,
bool startInclusive,
bool endInclusive);
/**
* Make a point interval from the provided object.
* The object must have exactly one field which is the value of the point interval.
*/
static Interval makePointInterval(const BSONObj& obj);
static Interval makePointInterval(const std::string& str);
static Interval makePointInterval(double d);
/**
* Since we have no BSONValue we must make an object that's a copy of a piece of another
* object.
*/
static BSONObj objFromElement(const BSONElement& elt);
/**
* Swap start/end in the provided interval.
*/
static void reverseInterval(Interval* ival);
/**
* Copied almost verbatim from db/queryutil.cpp.
*
* returns a std::string that when used as a matcher, would match a super set of regex()
*
* returns "" for complex regular expressions
*
* used to optimize queries in some simple regex cases that start with '^'
*/
static std::string simpleRegex(const char* regex,
const char* flags,
BoundsTightness* tightnessOut);
/**
* Returns an Interval from minKey to maxKey
*/
static Interval allValues();
static void translateRegex(const RegexMatchExpression* rme,
OrderedIntervalList* oil,
BoundsTightness* tightnessOut);
static void translateEquality(const BSONElement& data,
bool isHashed,
OrderedIntervalList* oil,
BoundsTightness* tightnessOut);
static void unionize(OrderedIntervalList* oilOut);
static void intersectize(const OrderedIntervalList& arg,
OrderedIntervalList* oilOut);
/**
* Fills out 'bounds' with the bounds for an index scan over all values of the
* index described by 'keyPattern' in the default forward direction.
*/
static void allValuesBounds(const BSONObj& keyPattern, IndexBounds* bounds);
/**
* Assumes each OIL in 'bounds' is increasing.
*
* Aligns OILs (and bounds) according to the 'kp' direction * the scanDir.
*/
static void alignBounds(IndexBounds* bounds, const BSONObj& kp, int scanDir = 1);
/**
* Returns 'true' if the bounds 'bounds' can be represented as one interval between
* 'startKey' and 'endKey'. Inclusivity of each bound is set through the relevant
* (name)KeyInclusive parameter. Returns 'false' if otherwise.
*/
static bool isSingleInterval(const IndexBounds& bounds,
BSONObj* startKey,
bool* startKeyInclusive,
BSONObj* endKey,
bool* endKeyInclusive);
};
} // namespace mongo
|