dom/localstorage/LSWriteOptimizer.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "LSWriteOptimizer.h"
   8
   9 #include <new>
  10 #include "nsBaseHashtable.h"
  11 #include "nsTArray.h"
  12
  13 namespace mozilla::dom {
  14
  15 class LSWriteOptimizerBase::WriteInfoComparator {
  16  public:
  17   bool Equals(const WriteInfo* a, const WriteInfo* b) const {
  18     MOZ_ASSERT(a && b);
  19     return a->SerialNumber() == b->SerialNumber();
  20   }
  21
  22   bool LessThan(const WriteInfo* a, const WriteInfo* b) const {
  23     MOZ_ASSERT(a && b);
  24     return a->SerialNumber() < b->SerialNumber();
  25   }
  26 };
  27
  28 void LSWriteOptimizerBase::DeleteItem(const nsAString& aKey, int64_t aDelta) {
  29   AssertIsOnOwningThread();
  30
  31   mWriteInfos.WithEntryHandle(aKey, [&](auto&& entry) {
  32     if (entry && entry.Data()->GetType() == WriteInfo::InsertItem) {
  33       entry.Remove();
  34     } else {
  35       entry.InsertOrUpdate(
  36           MakeUnique<DeleteItemInfo>(NextSerialNumber(), aKey));
  37     }
  38   });
  39
  40   mTotalDelta += aDelta;
  41 }
  42
  43 void LSWriteOptimizerBase::Truncate(int64_t aDelta) {
  44   AssertIsOnOwningThread();
  45
  46   mWriteInfos.Clear();
  47
  48   if (!mTruncateInfo) {
  49     mTruncateInfo = MakeUnique<TruncateInfo>(NextSerialNumber());
  50   }
  51
  52   mTotalDelta += aDelta;
  53 }
  54
  55 void LSWriteOptimizerBase::GetSortedWriteInfos(
  56     nsTArray<NotNull<WriteInfo*>>& aWriteInfos) {
  57   AssertIsOnOwningThread();
  58
  59   if (mTruncateInfo) {
  60     aWriteInfos.InsertElementSorted(WrapNotNullUnchecked(mTruncateInfo.get()),
  61                                     WriteInfoComparator());
  62   }
  63
  64   for (const auto& entry : mWriteInfos) {
  65     WriteInfo* writeInfo = entry.GetWeak();
  66
  67     aWriteInfos.InsertElementSorted(WrapNotNull(writeInfo),
  68                                     WriteInfoComparator());
  69   }
  70 }
  71
  72 }  // namespace mozilla::dom