LSWriteOptimizerImpl.h (2426B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=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 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef mozilla_dom_localstorage_LSWriteOptimizerImpl_h 8 #define mozilla_dom_localstorage_LSWriteOptimizerImpl_h 9 10 #include "LSWriteOptimizer.h" 11 12 namespace mozilla::dom { 13 14 template <typename T, typename U> 15 void LSWriteOptimizer<T, U>::InsertItem(const nsAString& aKey, const T& aValue, 16 int64_t aDelta) { 17 AssertIsOnOwningThread(); 18 19 mWriteInfos.WithEntryHandle(aKey, [&](auto&& entry) { 20 if (entry && entry.Data()->GetType() == WriteInfo::DeleteItem) { 21 // We could just simply replace the deletion with ordinary update, but 22 // that would preserve item's original position/index. Imagine a case when 23 // we have only one existing key k1. Now let's create a new optimizer and 24 // remove k1, add k2 and add k1 back. The final order should be k2, k1 25 // (ordinary update would produce k1, k2). So we need to differentiate 26 // between normal update and "optimized" update which resulted from a 27 // deletion followed by an insertion. We use the UpdateWithMove flag for 28 // this. 29 30 entry.Update(MakeUnique<UpdateItemInfo>(NextSerialNumber(), aKey, aValue, 31 /* aUpdateWithMove */ true)); 32 } else { 33 entry.InsertOrUpdate( 34 MakeUnique<InsertItemInfo>(NextSerialNumber(), aKey, aValue)); 35 } 36 }); 37 38 mTotalDelta += aDelta; 39 } 40 41 template <typename T, typename U> 42 void LSWriteOptimizer<T, U>::UpdateItem(const nsAString& aKey, const T& aValue, 43 int64_t aDelta) { 44 AssertIsOnOwningThread(); 45 46 mWriteInfos.WithEntryHandle(aKey, [&](auto&& entry) { 47 if (entry && entry.Data()->GetType() == WriteInfo::InsertItem) { 48 entry.Update( 49 MakeUnique<InsertItemInfo>(NextSerialNumber(), aKey, aValue)); 50 } else { 51 entry.InsertOrUpdate( 52 MakeUnique<UpdateItemInfo>(NextSerialNumber(), aKey, aValue, 53 /* aUpdateWithMove */ false)); 54 } 55 }); 56 57 mTotalDelta += aDelta; 58 } 59 60 } // namespace mozilla::dom 61 62 #endif // mozilla_dom_localstorage_LSWriteOptimizerImpl_h