Issue 5142 - Convert Element Hiding to C++

compiled/ElemHide.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 17 matching lines @@
 }
 
 void ElemHide::Clear()
 {
   mFilters.clear();
   mExceptions.clear();
   mFiltersByDomain.clear();
   mKnownExceptions.clear();
 }
 
-ActiveFilter::DomainMap ElemHide::defaultDomains;

[sergei, 2018/01/16 16:43:59]

It should be just
namespace
{
  const ActiveFilter::DomainMap defaultDomains = {{ActiveFilter::DEFAULT_DOMAIN,
true}};
}

[hub, 2018/01/19 02:11:03]

Done.

[sergei, 2018/01/22 15:40:07]

Do we really need it not in the anonymous namespace?

[hub, 2018/01/22 16:59:15]

Indeed we don't.

Done

-
-void ElemHide::AddToFiltersByDomain(ElemHideBase& filter)
-{
-  auto domains = filter.GetDomains();
+namespace
+{
+  const ActiveFilter::DomainMap defaultDomains =
+  {
+    { ActiveFilter::DEFAULT_DOMAIN, true }
+  };
+}
+
+void ElemHide::AddToFiltersByDomain(const ElemHideBasePtr& filter)
+{
+  const auto* domains = filter->GetDomains();
   if (!domains)
     domains = &defaultDomains;
 
-  DependentString text(filter.GetText());
-  for (auto& domain : *domains)

[sergei, 2018/01/16 16:43:59]

it should be `const auto&`.

[hub, 2018/01/19 02:11:04]

Done.

+  DependentString text(filter->GetText());
+  for (const auto& domain : *domains)
   {
     auto& filters = mFiltersByDomain[domain.first];
     if (domain.second)
-      filters[text] = ElemHideBasePtr(&filter);
+      filters[text] = filter;
     else
-    {
-      auto iter = filters.find(text);
-      if (iter != filters.end())
-        filters.erase(iter);
-    }
+      filters[text] = ElemHideBasePtr();
   }
 }
 
 void ElemHide::Add(ElemHideBase& filter)
 {
   // we must ensure we have the right class.
   // This is an error, but we might get Invalid filters.
   if (!filter.As<ElemHideBase>())
     return;
 
   DependentString text(filter.GetText());
   if (filter.mType == Filter::Type::ELEMHIDEEXCEPTION)

[sergei, 2018/01/16 18:05:27]

what about
if (auto exceptionFilter = filter.As<ElemHideException>())
{
  use exceptionFilter here.
}
and below too.

Can it happen that Filter::Type::ELEMHIDEEXCEPTION is just a mask and a simple
comparison is not enough?

[hub, 2018/01/19 02:11:03]

Done.
Filter::Type::ELEMHIDEEXCEPTION is not a mask, but Filter::As<> should be
enough.

   {
     if (mKnownExceptions.find(text))
       return;
 
     auto selector = filter.GetSelector();
     mExceptions[selector].emplace_back(filter.As<ElemHideException>());
 
-    // Selector is not longer unconditional
-    mUnconditionalSelectors.erase(text);
-    mUnconditionalSelectorsCache.reset();
+    // Selector is no longer unconditional
+    auto entry = mUnconditionalSelectors.find(selector);
+    if (entry && entry->second)
+    {
+      AddToFiltersByDomain(entry->second);
+      mUnconditionalSelectors.erase(selector);
+      mUnconditionalSelectorsCache.reset();
+    }
     mKnownExceptions.insert(text);
   }
   else
   {
     if (mFilters.find(text))
       return;
 
+    auto selector = filter.GetSelector();
     mFilters[text] = &filter;
     if (!((filter.GetDomains() && filter.GetDomains()->size()) ||
-          mExceptions.find(filter.GetSelector())))
+          mExceptions.find(selector)))
     {
       // The new filter's selector is unconditionally applied to all domains
-      mUnconditionalSelectors.insert(text);
+      mUnconditionalSelectors[selector] = ElemHideBasePtr(&filter);
       mUnconditionalSelectorsCache.reset();
     }
     else
-      AddToFiltersByDomain(filter);
+      AddToFiltersByDomain(ElemHideBasePtr(&filter));
   }
 }
 
 void ElemHide::Remove(ElemHideBase& filter)
 {
   DependentString text(filter.GetText());
 
-  if (filter.mType == Filter::Type::ELEMHIDEEXCEPTION)
+  auto selector = filter.GetSelector();
+  auto exceptionFilter = filter.As<ElemHideException>();
+  if (exceptionFilter)
   {
     // never seen the exception.
     if (!mKnownExceptions.find(text))
       return;
 
-    auto selector = filter.GetSelector();
     auto& list = mExceptions[selector];
-    auto iter = std::find(
-      list.begin(), list.end(),
-      ElemHideExceptionPtr(filter.As<ElemHideException>()));
+    auto iter = std::find(list.begin(), list.end(),
+                          ElemHideExceptionPtr(exceptionFilter));
     if (iter != list.end())
       list.erase(iter);
     mKnownExceptions.erase(text);
   }
   else
   {
     if (!mFilters.find(text))
       return;
 
-    if (mUnconditionalSelectors.find(text))
-    {
-      mUnconditionalSelectors.erase(text);
+    if (mUnconditionalSelectors.find(selector))
+    {
+      mUnconditionalSelectors.erase(selector);
       mUnconditionalSelectorsCache.reset();
     }
     else
     {
-      auto domains = filter.GetDomains();
-      for (auto domain : *domains)

[sergei, 2018/01/16 18:05:27]

Can domains be nullptr?

[hub, 2018/01/19 02:11:03]

Anything can happen. I check it elsewhere too.

Done

+      const auto* domains = filter.GetDomains();
+      if (!domains)
+        domains = &defaultDomains;
+
+      for (const auto& domain : *domains)
       {
         auto& list = mFiltersByDomain[domain.first];
         list.erase(text);
       }
     }
 
     mFilters.erase(text);
   }
 }
 
 ElemHideException* ElemHide::GetException(const ElemHideBase& filter,
                                           DependentString& docDomain) const
 {
   auto exception = mExceptions.find(filter.GetSelector());
   if (!exception)
     return nullptr;
 
   auto& list = exception->second;
   for (auto iter = list.rbegin(); iter != list.rend(); iter++)
   {
     DependentString domain(docDomain);
-    if ((*iter)->IsActiveOnDomain(domain, DependentString()))
+    if (*iter && (*iter)->IsActiveOnDomain(domain))
     {
       ElemHideExceptionPtr filter(*iter);
       return filter.release();
     }
   }
 
   return nullptr;
 }
 
 ElemHide_SelectorList* ElemHide::GetUnconditionalSelectors() const
 {
   if (!mUnconditionalSelectorsCache)
   {
     mUnconditionalSelectorsCache =
       intrusive_ptr<ElemHide_SelectorList>(new ElemHide_SelectorList(), false);
     annotate_address(mUnconditionalSelectorsCache.get(), "ElemHide_SelectorList");
-    for (auto unconditional : mUnconditionalSelectors)
-    {
-      auto entry = mFilters.find(unconditional.first);
-      if (entry)
-        mUnconditionalSelectorsCache->push_back(entry->second);
+    for (const auto& unconditional : mUnconditionalSelectors)
+    {
+      if (!(unconditional.is_deleted() || unconditional.is_invalid()))
+      {
+        auto entry = mFilters.find(unconditional.second->GetText());
+        if (entry)
+          mUnconditionalSelectorsCache->push_back(entry->second);
+      }
     }
   }
   return intrusive_ptr<ElemHide_SelectorList>(mUnconditionalSelectorsCache).release();
 }
 
 ElemHide_SelectorList* ElemHide::GetSelectorsForDomain(const String& domain,
   Criteria criteria) const
 {
   intrusive_ptr<ElemHide_SelectorList> selectors(new ElemHide_SelectorList());
   annotate_address(selectors.get(), "ElemHide_SelectorList");
 
   if (criteria < NO_UNCONDITIONAL)
   {
-    auto selector = GetUnconditionalSelectors();

[sergei, 2018/01/16 16:43:59]

what about using of intrusive_ptr?

[hub, 2018/01/19 02:11:03]

Done.

+    intrusive_ptr<ElemHide_SelectorList> selector(GetUnconditionalSelectors());
     selectors->append(*selector);
-    selector->ReleaseRef();
   }
 
   bool specificOnly = criteria >= SPECIFIC_ONLY;
   StringSet seenFilters;
   DependentString docDomain(domain);
 
   DependentString currentDomain(domain);
   while (true)
   {
     if (specificOnly && currentDomain.empty())
       break;
 
     auto filters = mFiltersByDomain.find(currentDomain);
     if (filters)
     {
-      for (auto& entry : filters->second)
+      for (const auto& entry : filters->second)
       {
         if (entry.first.is_invalid() || entry.first.is_deleted())

[sergei, 2018/01/16 16:43:59]

I have added https://issues.adblockplus.org/ticket/6280 and
https://issues.adblockplus.org/ticket/6281

[hub, 2018/01/19 02:11:04]

Acknowledged.

           continue;
 
         if (seenFilters.find(entry.first))
           continue;
         seenFilters.insert(entry.first);
 
         auto filter = entry.second;
         if (filter && !GetException(*filter, docDomain))
           selectors->push_back(filter);
       }
     }
 
     if (currentDomain.empty())
       break;
 
     auto nextDot = currentDomain.find(u'.');
     currentDomain = nextDot == String::npos ?
       u""_str : DependentString(currentDomain, nextDot + 1);
   }
 
   return selectors.release();
 }