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// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATA_FORMAT_VERSION_H_
#define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATA_FORMAT_VERSION_H_
#include <cstdint>
#include "base/check_op.h"
#include "content/common/content_export.h"
namespace content::indexed_db {
// Contains version data for the wire format used for encoding IndexedDB values.
// A version tuple (a, b) is at least as new as (a', b')
// iff a >= a' and b >= b'.
class IndexedDBDataFormatVersion {
public:
constexpr IndexedDBDataFormatVersion() {}
constexpr IndexedDBDataFormatVersion(uint32_t v8_version,
uint32_t blink_version)
: v8_version_(v8_version), blink_version_(blink_version) {}
static IndexedDBDataFormatVersion GetCurrent() { return current_; }
static IndexedDBDataFormatVersion& GetMutableCurrentForTesting() {
return current_;
}
uint32_t v8_version() const { return v8_version_; }
uint32_t blink_version() const { return blink_version_; }
friend bool operator==(const IndexedDBDataFormatVersion&,
const IndexedDBDataFormatVersion&) = default;
bool IsAtLeast(const IndexedDBDataFormatVersion& other) const {
return v8_version_ >= other.v8_version_ &&
blink_version_ >= other.blink_version_;
}
// Encodes and decodes the tuple from an int64_t.
// This scheme is chosen so that earlier versions (before we reported both the
// Blink and V8 versions) decode properly, with a V8 version of 0.
int64_t Encode() const {
// Since negative values are considered invalid, this scheme will only work
// as long as the v8 version would not overflow int32_t. We check both
// components, to be consistent.
DCHECK_GE(static_cast<int32_t>(v8_version_), 0);
DCHECK_GE(static_cast<int32_t>(blink_version_), 0);
return (static_cast<int64_t>(v8_version_) << 32) | blink_version_;
}
static IndexedDBDataFormatVersion Decode(int64_t encoded) {
DCHECK_GE(encoded, 0);
return IndexedDBDataFormatVersion(encoded >> 32, encoded);
}
private:
uint32_t v8_version_ = 0;
uint32_t blink_version_ = 0;
CONTENT_EXPORT static IndexedDBDataFormatVersion current_;
};
} // namespace content::indexed_db
#endif // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATA_FORMAT_VERSION_H_
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