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
|
/**
* 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/db/jsobj.h"
#include "mongo/util/hex.h"
#include "mongo/util/str.h"
namespace mongo {
/** A range of values for one field. */
struct Interval {
// No BSONValue means we have to keep a BSONObj and pointers (BSONElement) into it.
// 'start' may not point at the first field in _intervalData.
// 'end' may not point at the last field in _intervalData.
// 'start' and 'end' may point at the same field.
BSONObj _intervalData;
// Start and End must be ordered according to the index order.
BSONElement start;
bool startInclusive;
BSONElement end;
bool endInclusive;
/** Creates an empty interval */
Interval();
/**
* Generates a debug string for an interval. If interval 'hasNonSimpleCollation', then string
* bounds are hex-encoded.
*/
std::string toString(bool hasNonSimpleCollation) const {
str::stream ss;
if (startInclusive) {
ss << "[";
} else {
ss << "(";
}
auto boundToString = [&](BSONElement bound) {
if (bound.type() == BSONType::String && hasNonSimpleCollation) {
ss << "CollationKey(";
// False means omit the field name.
ss << "0x" << hexblob::encodeLower(bound.valueStringData());
ss << ")";
} else {
ss << bound.toString(false);
}
};
boundToString(start);
ss << ", ";
boundToString(end);
if (endInclusive) {
ss << "]";
} else {
ss << ")";
}
return ss;
}
/**
* Creates an interval that starts at the first field of 'base' and ends at the second
* field of 'base'. (In other words, 'base' is a bsonobj with at least two elements, of
* which we don't care about field names.)
*
* The interval's extremities are closed or not depending on whether
* 'start'/'endIncluded' are true or not.
*/
Interval(BSONObj base, bool startIncluded, bool endIncluded);
/** Sets the current interval to the given values (see constructor) */
void init(BSONObj base, bool startIncluded, bool endIncluded);
/**
* Returns true if an empty-constructed interval hasn't been init()-ialized yet
*/
bool isEmpty() const;
/**
* Does this interval represent exactly one point?
*/
bool isPoint() const;
/**
* Returns true if start is same as end and interval is open at either end
*/
bool isNull() const;
enum class Direction {
// Point intervals, empty intervals, and null intervals have no direction.
kDirectionNone,
kDirectionAscending,
kDirectionDescending
};
/**
* Compute the direction.
*/
Direction getDirection() const;
//
// Comparison with other intervals
//
/**
* Returns true if 'this' is the same interval as 'other'
*/
bool equals(const Interval& other) const;
/**
* Returns true if 'this' overlaps with 'other', false otherwise.
*/
bool intersects(const Interval& rhs) const;
/**
* Returns true if 'this' is within 'other', false otherwise.
*/
bool within(const Interval& other) const;
/**
* Returns true if 'this' is located before 'other', false otherwise.
*/
bool precedes(const Interval& other) const;
/**
* Returns true if the interval is from MinKey to MaxKey.
*/
bool isMinToMax() const;
/**
* Returns true if the interval is from MaxKey to MinKey.
*/
bool isMaxToMin() const;
/** Returns how 'this' compares to 'other' */
enum IntervalComparison {
//
// There is some intersection.
//
// The two intervals are *exactly* equal.
INTERVAL_EQUALS,
// 'this' contains the other interval.
INTERVAL_CONTAINS,
// 'this' is contained by the other interval.
INTERVAL_WITHIN,
// The two intervals intersect and 'this' is before the other interval.
INTERVAL_OVERLAPS_BEFORE,
// The two intervals intersect and 'this is after the other interval.
INTERVAL_OVERLAPS_AFTER,
//
// There is no intersection.
//
INTERVAL_PRECEDES,
// This happens if we have [a,b) [b,c]
INTERVAL_PRECEDES_COULD_UNION,
INTERVAL_SUCCEEDS,
INTERVAL_UNKNOWN
};
IntervalComparison compare(const Interval& other) const;
//
// Mutation of intervals
//
/**
* Swap start and end points of interval.
*/
void reverse();
/**
* Return a new Interval that's a reverse of this one.
*/
Interval reverseClone() const;
/**
* Updates 'this' with the intersection of 'this' and 'other'. If 'this' and 'other'
* have been compare()d before, that result can be optionally passed in 'cmp'
*/
void intersect(const Interval& other, IntervalComparison cmp = INTERVAL_UNKNOWN);
/**
* Updates 'this" with the union of 'this' and 'other'. If 'this' and 'other' have
* been compare()d before, that result can be optionaly passed in 'cmp'.
*/
void combine(const Interval& other, IntervalComparison cmp = INTERVAL_UNKNOWN);
};
inline bool operator==(const Interval& lhs, const Interval& rhs) {
return lhs.equals(rhs);
}
inline bool operator!=(const Interval& lhs, const Interval& rhs) {
return !(lhs == rhs);
}
} // namespace mongo
|
