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
|
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_UUID_H_
#define BASE_UUID_H_
#include <stdint.h>
#include <compare>
#include <iosfwd>
#include <string>
#include <string_view>
#include "base/base_export.h"
#include "base/compiler_specific.h"
#include "base/containers/span.h"
namespace base {
class BASE_EXPORT Uuid {
public:
// Length in bytes of the input required to format the input as a Uuid in the
// form of version 4.
static constexpr size_t kGuidV4InputLength = 16;
// Generate a 128-bit random Uuid in the form of version 4. see RFC 4122,
// section 4.4. The format of Uuid version 4 must be
// xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where y is one of [8, 9, a, b]. The
// hexadecimal values "a" through "f" are output as lower case characters.
// A cryptographically secure random source will be used, but consider using
// UnguessableToken for greater type-safety if Uuid format is unnecessary.
static Uuid GenerateRandomV4();
// Returns a valid Uuid if the input string conforms to the Uuid format, and
// an invalid Uuid otherwise. Note that this does NOT check if the hexadecimal
// values "a" through "f" are in lower case characters.
static Uuid ParseCaseInsensitive(std::string_view input);
static Uuid ParseCaseInsensitive(std::u16string_view input);
// Similar to ParseCaseInsensitive(), but all hexadecimal values "a" through
// "f" must be lower case characters.
static Uuid ParseLowercase(std::string_view input);
static Uuid ParseLowercase(std::u16string_view input);
// Constructs an invalid Uuid.
Uuid();
Uuid(const Uuid& other);
Uuid& operator=(const Uuid& other);
Uuid(Uuid&& other);
Uuid& operator=(Uuid&& other);
bool is_valid() const { return !lowercase_.empty(); }
// Returns the Uuid in a lowercase string format if it is valid, and an empty
// string otherwise. The returned value is guaranteed to be parsed by
// ParseLowercase().
//
// NOTE: While AsLowercaseString() is currently a trivial getter, callers
// should not treat it as such. When the internal type of base::Uuid changes,
// this will be a non-trivial converter. See the TODO above `lowercase_` for
// more context.
const std::string& AsLowercaseString() const LIFETIME_BOUND;
// Invalid Uuids are equal.
friend bool operator==(const Uuid&, const Uuid&) = default;
// Uuids are 128bit chunks of data so must be indistinguishable if equivalent.
friend std::strong_ordering operator<=>(const Uuid&, const Uuid&) = default;
private:
static Uuid FormatRandomDataAsV4Impl(
base::span<const uint8_t, kGuidV4InputLength> input);
// TODO(crbug.com/40108138): Consider using a different internal type.
// Most existing representations of Uuids in the codebase use std::string,
// so matching the internal type will avoid inefficient string conversions
// during the migration to base::Uuid.
//
// The lowercase form of the Uuid. Empty for invalid Uuids.
std::string lowercase_;
};
// For runtime usage only. Do not store the result of this hash, as it may
// change in future Chromium revisions.
struct BASE_EXPORT UuidHash {
size_t operator()(const Uuid& uuid) const;
};
// Stream operator so Uuid objects can be used in logging statements.
BASE_EXPORT std::ostream& operator<<(std::ostream& out, const Uuid& uuid);
} // namespace base
#endif // BASE_UUID_H_
|
