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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 // This scheme is chosen so that earlier versions (before we reported both the |
| 49 // Blink and V8 versions) decode properly, with a V8 version of 0. |
| 50 int64_t Encode() const { |
| 51 // Since negative values are considered invalid, this scheme will only work |
| 52 // as long as the v8 version would not overflow int32_t. We check both |
| 53 // components, to be consistent. |
| 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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