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
|
/**
* Copyright (C) 2020-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 <algorithm>
#include "mongo/bson/json.h"
#include "mongo/db/exec/document_value/document.h"
#include "mongo/db/exec/document_value/value.h"
#include "mongo/db/update/document_diff_applier.h"
#include "mongo/db/update/document_diff_calculator.h"
#include "mongo/platform/random.h"
#include "mongo/unittest/bson_test_util.h"
#include "mongo/unittest/unittest.h"
namespace mongo::doc_diff {
BSONObj createObjWithLargePrefix(const std::string& suffix) {
const static auto largeObj = BSON("prefixLargeField" << std::string(200, 'a'));
return largeObj.addFields(fromjson(suffix));
}
std::string getFieldName(int level, int fieldNum) {
return str::stream() << "f" << level << fieldNum;
}
Value getScalarFieldValue(PseudoRandom* rng) {
switch (rng->nextInt32(10)) {
case 0:
return Value("val"_sd);
case 1:
return Value(BSONNULL);
case 2:
return Value(-1LL);
case 3:
return Value(0);
case 4:
return Value(1.10);
case 5:
return Value(false);
case 6:
return Value(BSONRegEx("p"));
case 7:
return Value(Date_t());
case 8:
return Value(UUID::gen());
case 9:
return Value(BSONBinData("asdf", 4, BinDataGeneral));
default:
MONGO_UNREACHABLE;
}
}
BSONObj generateDoc(PseudoRandom* rng, MutableDocument* doc, int depthLevel) {
// Append a large field at each level so that the likelihood of generating a sub-diff is high.
auto largeFieldObj = createObjWithLargePrefix("{}");
doc->addField("prefixLargeField", Value(largeFieldObj.firstElement()));
// Reduce the probabilty of generated nested objects as we go deeper. After depth level 6, we
// should not be generating anymore nested objects.
const double subObjProbability = 0.3 - (depthLevel * 0.05);
const double subArrayProbability = 0.2 - (depthLevel * 0.05);
const int numFields = (5 - depthLevel) + rng->nextInt32(4);
for (int fieldNum = 0; fieldNum < numFields; ++fieldNum) {
const auto fieldName = getFieldName(depthLevel, fieldNum);
auto num = rng->nextCanonicalDouble();
if (num <= subObjProbability) {
MutableDocument subDoc;
doc->addField(fieldName, Value(generateDoc(rng, &subDoc, depthLevel + 1)));
} else if (num <= (subObjProbability + subArrayProbability)) {
const auto arrayLength = rng->nextInt32(10);
std::vector<Value> values;
auto numSubObjs = 0;
for (auto i = 0; i < arrayLength; i++) {
// The probablilty of generating a sub-object goes down as we generate more
// sub-objects and as the array position increases.
if (!rng->nextInt32(2 + numSubObjs + i)) {
MutableDocument subDoc;
// Ensure that the depth is higher as we generate more sub-objects, to avoid
// bloating up the document size exponentially.
values.push_back(
Value(generateDoc(rng, &subDoc, depthLevel + 1 + numSubObjs * 2)));
++numSubObjs;
} else {
values.push_back(getScalarFieldValue(rng));
}
}
doc->addField(fieldName, Value(values));
} else {
doc->addField(fieldName, getScalarFieldValue(rng));
}
}
return doc->freeze().toBson();
}
} // namespace mongo::doc_diff
|
