gecko-dev/dom/localstorage/LSWriteOptimizer.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=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/. */

#include "LSWriteOptimizer.h"

#include <new>
#include "nsBaseHashtable.h"
#include "nsTArray.h"

namespace mozilla::dom {

class LSWriteOptimizerBase::WriteInfoComparator {
 public:
  bool Equals(const WriteInfo* a, const WriteInfo* b) const {
    MOZ_ASSERT(a && b);
    return a->SerialNumber() == b->SerialNumber();
  }

  bool LessThan(const WriteInfo* a, const WriteInfo* b) const {
    MOZ_ASSERT(a && b);
    return a->SerialNumber() < b->SerialNumber();
  }
};

void LSWriteOptimizerBase::DeleteItem(const nsAString& aKey, int64_t aDelta) {
  AssertIsOnOwningThread();

  mWriteInfos.WithEntryHandle(aKey, [&](auto&& entry) {
    if (entry && entry.Data()->GetType() == WriteInfo::InsertItem) {
      entry.Remove();
    } else {
      entry.InsertOrUpdate(
          MakeUnique<DeleteItemInfo>(NextSerialNumber(), aKey));
    }
  });

  mTotalDelta += aDelta;
}

void LSWriteOptimizerBase::Truncate(int64_t aDelta) {
  AssertIsOnOwningThread();

  mWriteInfos.Clear();

  if (!mTruncateInfo) {
    mTruncateInfo = MakeUnique<TruncateInfo>(NextSerialNumber());
  }

  mTotalDelta += aDelta;
}

void LSWriteOptimizerBase::GetSortedWriteInfos(
    nsTArray<NotNull<WriteInfo*>>& aWriteInfos) {
  AssertIsOnOwningThread();

  if (mTruncateInfo) {
    aWriteInfos.InsertElementSorted(WrapNotNullUnchecked(mTruncateInfo.get()),
                                    WriteInfoComparator());
  }

  for (const auto& entry : mWriteInfos) {
    WriteInfo* writeInfo = entry.GetWeak();

    aWriteInfos.InsertElementSorted(WrapNotNull(writeInfo),
                                    WriteInfoComparator());
  }
}

}  // namespace mozilla::dom