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
|
/**
* 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.
*/
#include "mongo/platform/basic.h"
#include "mongo/bson/oid.h"
#include <boost/functional/hash.hpp>
#include <limits>
#include <memory>
#include "mongo/base/init.h"
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/platform/atomic_word.h"
#include "mongo/platform/random.h"
#include "mongo/util/hex.h"
namespace mongo {
namespace {
std::unique_ptr<AtomicWord<int64_t>> counter;
const std::size_t kTimestampOffset = 0;
const std::size_t kInstanceUniqueOffset = kTimestampOffset + OID::kTimestampSize;
const std::size_t kIncrementOffset = kInstanceUniqueOffset + OID::kInstanceUniqueSize;
OID::InstanceUnique _instanceUnique;
} // namespace
MONGO_INITIALIZER_GENERAL(OIDGeneration, MONGO_NO_PREREQUISITES, ("default"))
(InitializerContext* context) {
std::unique_ptr<SecureRandom> entropy(SecureRandom::create());
counter = std::make_unique<AtomicWord<int64_t>>(entropy->nextInt64());
_instanceUnique = OID::InstanceUnique::generate(*entropy);
return Status::OK();
}
OID::Increment OID::Increment::next() {
uint64_t nextCtr = counter->fetchAndAdd(1);
OID::Increment incr;
incr.bytes[0] = uint8_t(nextCtr >> 16);
incr.bytes[1] = uint8_t(nextCtr >> 8);
incr.bytes[2] = uint8_t(nextCtr);
return incr;
}
OID::InstanceUnique OID::InstanceUnique::generate(SecureRandom& entropy) {
int64_t rand = entropy.nextInt64();
OID::InstanceUnique u;
std::memcpy(u.bytes, &rand, kInstanceUniqueSize);
return u;
}
void OID::setTimestamp(const OID::Timestamp timestamp) {
_view().write<BigEndian<Timestamp>>(timestamp, kTimestampOffset);
}
void OID::setInstanceUnique(const OID::InstanceUnique unique) {
// Byte order doesn't matter here
_view().write<InstanceUnique>(unique, kInstanceUniqueOffset);
}
void OID::setIncrement(const OID::Increment inc) {
_view().write<Increment>(inc, kIncrementOffset);
}
OID::Timestamp OID::getTimestamp() const {
return view().read<BigEndian<Timestamp>>(kTimestampOffset);
}
OID::InstanceUnique OID::getInstanceUnique() const {
// Byte order doesn't matter here
return view().read<InstanceUnique>(kInstanceUniqueOffset);
}
OID::Increment OID::getIncrement() const {
return view().read<Increment>(kIncrementOffset);
}
void OID::hash_combine(size_t& seed) const {
uint32_t v;
for (int i = 0; i != kOIDSize; i += sizeof(uint32_t)) {
memcpy(&v, _data + i, sizeof(uint32_t));
boost::hash_combine(seed, v);
}
}
size_t OID::Hasher::operator()(const OID& oid) const {
size_t seed = 0;
oid.hash_combine(seed);
return seed;
}
void OID::regenMachineId() {
std::unique_ptr<SecureRandom> entropy(SecureRandom::create());
_instanceUnique = InstanceUnique::generate(*entropy);
}
unsigned OID::getMachineId() {
uint32_t ret = 0;
std::memcpy(&ret, _instanceUnique.bytes, sizeof(uint32_t));
return ret;
}
void OID::justForked() {
regenMachineId();
}
void OID::init() {
// each set* method handles endianness
setTimestamp(time(nullptr));
setInstanceUnique(_instanceUnique);
setIncrement(Increment::next());
}
void OID::initFromTermNumber(int64_t term) {
// Each set* method handles endianness.
// Set max timestamp because the drivers compare ElectionId's to determine valid new primaries,
// and we want ElectionId's with terms to supercede ones without terms.
setTimestamp(std::numeric_limits<Timestamp>::max());
_view().write<BigEndian<int64_t>>(term, kInstanceUniqueOffset);
}
void OID::init(const std::string& s) {
verify(s.size() == 24);
const char* p = s.c_str();
for (std::size_t i = 0; i < kOIDSize; i++) {
_data[i] = uassertStatusOK(fromHex(p));
p += 2;
}
}
void OID::init(Date_t date, bool max) {
setTimestamp(uint32_t(date.toMillisSinceEpoch() / 1000));
uint64_t rest = max ? std::numeric_limits<uint64_t>::max() : 0u;
std::memcpy(_view().view(kInstanceUniqueOffset), &rest, kInstanceUniqueSize + kIncrementSize);
}
time_t OID::asTimeT() const {
return getTimestamp();
}
std::string OID::toString() const {
return toHexLower(_data, kOIDSize);
}
std::string OID::toIncString() const {
return toHexLower(getIncrement().bytes, kIncrementSize);
}
} // namespace mongo
|
