gecko-dev/dom/quota/UsageInfo.h

/* -*- 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 "mozilla/dom/quota/QuotaCommon.h"

#include "mozilla/Atomics.h"
#include "mozilla/CheckedInt.h"

BEGIN_QUOTA_NAMESPACE

class UsageInfo {
 public:
  UsageInfo() : mDatabaseUsage(0), mFileUsage(0), mLimit(0) {}

  virtual ~UsageInfo() {}

  void Append(const UsageInfo& aUsageInfo) {
    IncrementUsage(&mDatabaseUsage, aUsageInfo.mDatabaseUsage);
    IncrementUsage(&mFileUsage, aUsageInfo.mFileUsage);
  }

  void AppendToDatabaseUsage(uint64_t aUsage) {
    IncrementUsage(&mDatabaseUsage, aUsage);
  }

  void AppendToFileUsage(uint64_t aUsage) {
    IncrementUsage(&mFileUsage, aUsage);
  }

  void SetLimit(uint64_t aLimit) { mLimit = aLimit; }

  uint64_t DatabaseUsage() { return mDatabaseUsage; }

  uint64_t FileUsage() { return mFileUsage; }

  uint64_t Limit() { return mLimit; }

  uint64_t TotalUsage() {
    uint64_t totalUsage = mDatabaseUsage;
    IncrementUsage(&totalUsage, mFileUsage);
    return totalUsage;
  }

  void ResetUsage() {
    mDatabaseUsage = 0;
    mFileUsage = 0;
  }

  static void IncrementUsage(uint64_t* aUsage, uint64_t aDelta) {
    MOZ_ASSERT(aUsage);
    CheckedUint64 value = *aUsage;
    value += aDelta;
    if (value.isValid()) {
      *aUsage = value.value();
    } else {
      *aUsage = UINT64_MAX;
    }
  }

 private:
  uint64_t mDatabaseUsage;
  uint64_t mFileUsage;
  uint64_t mLimit;
};

END_QUOTA_NAMESPACE

#endif  // mozilla_dom_quota_usageinfo_h__