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
|
/**
* 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/db/query/collation/collator_interface_icu.h"
#include <memory>
#include <unicode/coll.h>
#include <unicode/sortkey.h>
#include "mongo/util/assert_util.h"
namespace mongo {
CollatorInterfaceICU::CollatorInterfaceICU(Collation spec, std::unique_ptr<icu::Collator> collator)
: CollatorInterface(std::move(spec)), _collator(std::move(collator)) {}
std::unique_ptr<CollatorInterface> CollatorInterfaceICU::clone() const {
auto clone = std::make_unique<CollatorInterfaceICU>(
getSpec(), std::unique_ptr<icu::Collator>(_collator->clone()));
return {std::move(clone)};
}
int CollatorInterfaceICU::compare(StringData left, StringData right) const {
UErrorCode status = U_ZERO_ERROR;
auto compareResult = _collator->compareUTF8(icu::StringPiece(left.rawData(), left.size()),
icu::StringPiece(right.rawData(), right.size()),
status);
// Any sequence of bytes, even invalid UTF-8, has defined comparison behavior in ICU (invalid
// subsequences are weighted as the replacement character, U+FFFD). A non-ok error code is only
// expected when a memory allocation fails inside ICU, which we consider fatal to the process.
fassert(34438, U_SUCCESS(status));
switch (compareResult) {
case UCOL_EQUAL:
return 0;
case UCOL_GREATER:
return 1;
case UCOL_LESS:
return -1;
}
MONGO_UNREACHABLE;
}
CollatorInterface::ComparisonKey CollatorInterfaceICU::getComparisonKey(
StringData stringData) const {
// A StringPiece is ICU's StringData. They are logically the same abstraction.
const icu::StringPiece stringPiece(stringData.rawData(), stringData.size());
UErrorCode status = U_ZERO_ERROR;
icu::CollationKey icuKey;
_collator->getCollationKey(icu::UnicodeString::fromUTF8(stringPiece), icuKey, status);
// Any sequence of bytes, even invalid UTF-8, has defined comparison behavior in ICU (invalid
// subsequences are weighted as the replacement character, U+FFFD). A non-ok error code is only
// expected when a memory allocation fails inside ICU, which we consider fatal to the process.
fassert(34439, U_SUCCESS(status));
int32_t keyLength;
const uint8_t* keyBuffer = icuKey.getByteArray(keyLength);
invariant(keyLength > 0);
invariant(keyBuffer);
// The last byte of the sort key should always be null. When we construct the comparison key, we
// omit the trailing null byte.
invariant(keyBuffer[keyLength - 1u] == '\0');
const char* charBuffer = reinterpret_cast<const char*>(keyBuffer);
return makeComparisonKey(std::string(charBuffer, keyLength - 1u));
}
} // namespace mongo
|