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1 // Copyright 2017 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATA_FORMAT_VERSION_H_ | |
6 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATA_FORMAT_VERSION_H_ | |
7 | |
8 #include <cstdint> | |
9 #include <limits> | |
10 | |
11 #include "base/logging.h" | |
12 #include "content/common/content_export.h" | |
13 | |
14 namespace content { | |
15 | |
16 // Contains version data for the wire format used for encoding IndexedDB values. | |
17 // A version tuple (a, b) is at least as new as (a', b') | |
18 // iff a >= a' and b >= b'. | |
19 class IndexedDBDataFormatVersion { | |
20 public: | |
21 constexpr IndexedDBDataFormatVersion() {} | |
22 constexpr IndexedDBDataFormatVersion(uint32_t v8_version, | |
23 uint32_t blink_version) | |
24 : v8_version_(v8_version), blink_version_(blink_version) {} | |
25 | |
26 static IndexedDBDataFormatVersion GetCurrent() { return current_; } | |
27 static IndexedDBDataFormatVersion& GetMutableCurrentForTesting() { | |
28 return current_; | |
29 } | |
30 | |
31 uint32_t v8_version() const { return v8_version_; } | |
32 uint32_t blink_version() const { return blink_version_; } | |
33 | |
34 bool operator==(const IndexedDBDataFormatVersion& other) const { | |
35 return v8_version_ == other.v8_version_ && | |
36 blink_version_ == other.blink_version_; | |
37 } | |
38 bool operator!=(const IndexedDBDataFormatVersion& other) const { | |
39 return !operator==(other); | |
40 } | |
41 | |
42 bool IsAtLeast(const IndexedDBDataFormatVersion& other) const { | |
43 return v8_version_ >= other.v8_version_ && | |
44 blink_version_ >= other.blink_version_; | |
45 } | |
46 | |
47 // Encodes and decodes the tuple from an int64_t. | |
48 // Since negative values are considered invalid, this scheme will only work | |
jsbell
2017/04/07 16:30:01
Seems like there's a word or two missing in this s
jbroman
2017/04/07 17:50:14
Done.
| |
49 // the v8 version would overflow int32_t. We check both, to be consistent. | |
50 // | |
51 // This scheme is chosen so that earlier versions (before we reported both the | |
52 // Blink and V8 versions) decode properly, with a V8 version of 0. | |
53 int64_t Encode() const { | |
54 DCHECK_GE(static_cast<int32_t>(v8_version_), 0); | |
55 DCHECK_GE(static_cast<int32_t>(blink_version_), 0); | |
56 return (static_cast<int64_t>(v8_version_) << 32) | blink_version_; | |
57 } | |
58 static IndexedDBDataFormatVersion Decode(int64_t encoded) { | |
59 DCHECK_GE(encoded, 0); | |
60 return IndexedDBDataFormatVersion(encoded >> 32, encoded); | |
61 } | |
62 | |
63 private: | |
64 uint32_t v8_version_ = 0; | |
65 uint32_t blink_version_ = 0; | |
66 | |
67 CONTENT_EXPORT static IndexedDBDataFormatVersion current_; | |
68 }; | |
69 | |
70 } // namespace content | |
71 | |
72 #endif // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATA_FORMAT_VERSION_H_ | |
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