gecko-dev/dom/quota/UsageInfo.h

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2.5 KiB
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_dom_quota_usageinfo_h__
#define mozilla_dom_quota_usageinfo_h__
#include <cstdint>
#include <utility>
#include "mozilla/CheckedInt.h"
#include "mozilla/Maybe.h"
namespace mozilla::dom::quota {
enum struct UsageKind { Database, File };
namespace detail {
inline void AddCapped(Maybe<uint64_t>& aValue, const Maybe<uint64_t> aDelta) {
if (aDelta.isSome()) {
CheckedUint64 value = aValue.valueOr(0);
value += aDelta.value();
aValue = Some(value.isValid() ? value.value() : UINT64_MAX);
}
}
template <UsageKind Kind>
struct Usage {
explicit Usage(Maybe<uint64_t> aValue = Nothing{}) : mValue(aValue) {}
Maybe<uint64_t> GetValue() const { return mValue; }
Usage& operator+=(const Usage aDelta) {
AddCapped(mValue, aDelta.mValue);
return *this;
}
Usage operator+(const Usage aDelta) const {
Usage res = *this;
res += aDelta;
return res;
}
private:
Maybe<uint64_t> mValue;
};
} // namespace detail
using DatabaseUsageType = detail::Usage<UsageKind::Database>;
using FileUsageType = detail::Usage<UsageKind::File>;
class UsageInfo final {
public:
UsageInfo() = default;
explicit UsageInfo(const DatabaseUsageType aUsage) : mDatabaseUsage(aUsage) {}
explicit UsageInfo(const FileUsageType aUsage) : mFileUsage(aUsage) {}
UsageInfo operator+(const UsageInfo& aUsageInfo) {
UsageInfo res = *this;
res += aUsageInfo;
return res;
}
UsageInfo& operator+=(const UsageInfo& aUsageInfo) {
mDatabaseUsage += aUsageInfo.mDatabaseUsage;
mFileUsage += aUsageInfo.mFileUsage;
return *this;
}
UsageInfo& operator+=(const DatabaseUsageType aUsage) {
mDatabaseUsage += aUsage;
return *this;
}
UsageInfo& operator+=(const FileUsageType aUsage) {
mFileUsage += aUsage;
return *this;
}
Maybe<uint64_t> DatabaseUsage() const { return mDatabaseUsage.GetValue(); }
Maybe<uint64_t> FileUsage() const { return mFileUsage.GetValue(); }
Maybe<uint64_t> TotalUsage() const {
Maybe<uint64_t> res = mDatabaseUsage.GetValue();
detail::AddCapped(res, FileUsage());
return res;
}
private:
DatabaseUsageType mDatabaseUsage;
FileUsageType mFileUsage;
};
} // namespace mozilla::dom::quota
#endif // mozilla_dom_quota_usageinfo_h__