tor-browser

SessionStorageCache.cpp (8319B)

---

/* -*- 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/. */

#include "SessionStorageCache.h"

#include "LocalStorageManager.h"
#include "StorageIPC.h"
#include "mozilla/Assertions.h"
#include "mozilla/dom/LSWriteOptimizer.h"
#include "mozilla/dom/PBackgroundSessionStorageCache.h"
#include "nsDOMString.h"

namespace mozilla::dom {

void SSWriteOptimizer::Enumerate(nsTArray<SSWriteInfo>& aWriteInfos) {
 AssertIsOnOwningThread();

 // The mWriteInfos hash table contains all write infos, but it keeps them in
 // an arbitrary order, which means write infos need to be sorted before being
 // processed.

 nsTArray<NotNull<WriteInfo*>> writeInfos;
 GetSortedWriteInfos(writeInfos);

 for (const auto& writeInfo : writeInfos) {
   switch (writeInfo->GetType()) {
     case WriteInfo::InsertItem: {
       const auto& insertItemInfo =
           static_cast<const InsertItemInfo&>(*writeInfo);

       aWriteInfos.AppendElement(
           SSSetItemInfo{nsString{insertItemInfo.GetKey()},
                         nsString{insertItemInfo.GetValue()}});

       break;
     }

     case WriteInfo::UpdateItem: {
       const auto& updateItemInfo =
           static_cast<const UpdateItemInfo&>(*writeInfo);

       if (updateItemInfo.UpdateWithMove()) {
         // See the comment in LSWriteOptimizer::InsertItem for more details
         // about the UpdateWithMove flag.

         aWriteInfos.AppendElement(
             SSRemoveItemInfo{nsString{updateItemInfo.GetKey()}});
       }

       aWriteInfos.AppendElement(
           SSSetItemInfo{nsString{updateItemInfo.GetKey()},
                         nsString{updateItemInfo.GetValue()}});

       break;
     }

     case WriteInfo::DeleteItem: {
       const auto& deleteItemInfo =
           static_cast<const DeleteItemInfo&>(*writeInfo);

       aWriteInfos.AppendElement(
           SSRemoveItemInfo{nsString{deleteItemInfo.GetKey()}});

       break;
     }

     case WriteInfo::Truncate: {
       aWriteInfos.AppendElement(SSClearInfo{});

       break;
     }

     default:
       MOZ_CRASH("Bad type!");
   }
 }
}

SessionStorageCache::SessionStorageCache()
   : mActor(nullptr), mLoadedOrCloned(false) {}

SessionStorageCache::~SessionStorageCache() {
 if (mActor) {
   mActor->SendDeleteMeInternal();
   MOZ_ASSERT(!mActor, "SendDeleteMeInternal should have cleared!");
 }
}

int64_t SessionStorageCache::GetOriginQuotaUsage() {
 return mDataSet.mOriginQuotaUsage;
}

uint32_t SessionStorageCache::Length() { return mDataSet.mKeys.Count(); }

void SessionStorageCache::Key(uint32_t aIndex, nsAString& aResult) {
 aResult.SetIsVoid(true);
 for (auto iter = mDataSet.mKeys.ConstIter(); !iter.Done(); iter.Next()) {
   if (aIndex == 0) {
     aResult = iter.Key();
     return;
   }
   aIndex--;
 }
}

void SessionStorageCache::GetItem(const nsAString& aKey, nsAString& aResult) {
 // not using AutoString since we don't want to copy buffer to result
 nsString value;
 if (!mDataSet.mKeys.Get(aKey, &value)) {
   SetDOMStringToNull(value);
 }
 aResult = value;
}

void SessionStorageCache::GetKeys(nsTArray<nsString>& aKeys) {
 AppendToArray(aKeys, mDataSet.mKeys.Keys());
}

nsresult SessionStorageCache::SetItem(const nsAString& aKey,
                                     const nsAString& aValue,
                                     nsString& aOldValue,
                                     bool aRecordWriteInfo) {
 int64_t delta = 0;

 if (!mDataSet.mKeys.Get(aKey, &aOldValue)) {
   SetDOMStringToNull(aOldValue);

   // We only consider key size if the key doesn't exist before.
   delta = static_cast<int64_t>(aKey.Length());
 }

 delta += static_cast<int64_t>(aValue.Length()) -
          static_cast<int64_t>(aOldValue.Length());

 if (aValue == aOldValue &&
     DOMStringIsNull(aValue) == DOMStringIsNull(aOldValue)) {
   return NS_SUCCESS_DOM_NO_OPERATION;
 }

 if (!mDataSet.ProcessUsageDelta(delta)) {
   return NS_ERROR_DOM_QUOTA_EXCEEDED_ERR;
 }

 if (aRecordWriteInfo && XRE_IsContentProcess()) {
   if (DOMStringIsNull(aOldValue)) {
     mDataSet.mWriteOptimizer.InsertItem(aKey, aValue);
   } else {
     mDataSet.mWriteOptimizer.UpdateItem(aKey, aValue);
   }
 }

 mDataSet.mKeys.InsertOrUpdate(aKey, nsString(aValue));
 return NS_OK;
}

nsresult SessionStorageCache::RemoveItem(const nsAString& aKey,
                                        nsString& aOldValue,
                                        bool aRecordWriteInfo) {
 if (!mDataSet.mKeys.Get(aKey, &aOldValue)) {
   return NS_SUCCESS_DOM_NO_OPERATION;
 }

 // Recalculate the cached data size
 mDataSet.ProcessUsageDelta(-(static_cast<int64_t>(aOldValue.Length()) +
                              static_cast<int64_t>(aKey.Length())));

 if (aRecordWriteInfo && XRE_IsContentProcess()) {
   mDataSet.mWriteOptimizer.DeleteItem(aKey);
 }

 mDataSet.mKeys.Remove(aKey);
 return NS_OK;
}

void SessionStorageCache::Clear(bool aByUserInteraction,
                               bool aRecordWriteInfo) {
 mDataSet.ProcessUsageDelta(-mDataSet.mOriginQuotaUsage);

 if (aRecordWriteInfo && XRE_IsContentProcess()) {
   mDataSet.mWriteOptimizer.Truncate();
 }

 mDataSet.mKeys.Clear();
}

void SessionStorageCache::ResetWriteInfos() {
 mDataSet.mWriteOptimizer.Reset();
}

already_AddRefed<SessionStorageCache> SessionStorageCache::Clone() const {
 RefPtr<SessionStorageCache> cache = new SessionStorageCache();

 cache->mDataSet.mOriginQuotaUsage = mDataSet.mOriginQuotaUsage;
 for (const auto& keyEntry : mDataSet.mKeys) {
   cache->mDataSet.mKeys.InsertOrUpdate(keyEntry.GetKey(), keyEntry.GetData());
   cache->mDataSet.mWriteOptimizer.InsertItem(keyEntry.GetKey(),
                                              keyEntry.GetData());
 }

 return cache.forget();
}

nsTArray<SSSetItemInfo> SessionStorageCache::SerializeData() {
 nsTArray<SSSetItemInfo> data;
 for (const auto& keyEntry : mDataSet.mKeys) {
   data.EmplaceBack(nsString{keyEntry.GetKey()}, keyEntry.GetData());
 }
 return data;
}

nsTArray<SSWriteInfo> SessionStorageCache::SerializeWriteInfos() {
 nsTArray<SSWriteInfo> writeInfos;
 mDataSet.mWriteOptimizer.Enumerate(writeInfos);
 return writeInfos;
}

void SessionStorageCache::DeserializeData(
   const nsTArray<SSSetItemInfo>& aData) {
 Clear(false, /* aRecordWriteInfo */ false);
 for (const auto& keyValuePair : aData) {
   nsString oldValue;
   SetItem(keyValuePair.key(), keyValuePair.value(), oldValue, false);
 }
}

void SessionStorageCache::DeserializeWriteInfos(
   const nsTArray<SSWriteInfo>& aInfos) {
 for (const auto& writeInfo : aInfos) {
   switch (writeInfo.type()) {
     case SSWriteInfo::TSSSetItemInfo: {
       const SSSetItemInfo& info = writeInfo.get_SSSetItemInfo();

       nsString oldValue;
       SetItem(info.key(), info.value(), oldValue,
               /* aRecordWriteInfo */ false);

       break;
     }

     case SSWriteInfo::TSSRemoveItemInfo: {
       const SSRemoveItemInfo& info = writeInfo.get_SSRemoveItemInfo();

       nsString oldValue;
       RemoveItem(info.key(), oldValue,
                  /* aRecordWriteInfo */ false);

       break;
     }

     case SSWriteInfo::TSSClearInfo: {
       Clear(false, /* aRecordWriteInfo */ false);

       break;
     }

     default:
       MOZ_CRASH("Should never get here!");
   }
 }
}

void SessionStorageCache::SetActor(SessionStorageCacheChild* aActor) {
 AssertIsOnMainThread();
 MOZ_ASSERT(aActor);
 MOZ_ASSERT(!mActor);

 mActor = aActor;
}

void SessionStorageCache::ClearActor() {
 AssertIsOnMainThread();
 MOZ_ASSERT(mActor);

 mActor = nullptr;
}

bool SessionStorageCache::DataSet::ProcessUsageDelta(int64_t aDelta) {
 // Check limit per this origin
 uint64_t newOriginUsage = mOriginQuotaUsage + aDelta;
 if (aDelta > 0 && newOriginUsage > LocalStorageManager::GetOriginQuota()) {
   return false;
 }

 // Update size in our data set
 mOriginQuotaUsage = newOriginUsage;
 return true;
}

}  // namespace mozilla::dom