Issue 5013 - Make more methods const.- introduced JsConstValuePtr and JsConstValueList- JsValue:…

src/FilterEngine.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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 39 matching lines @@
     return TYPE_ELEMHIDE_EXCEPTION;
   else if (className == "CommentFilter")
     return TYPE_COMMENT;
   else
     return TYPE_INVALID;
 }
 
 bool Filter::IsListed() const
 {
   JsValuePtr func = jsEngine->Evaluate("API.isListedFilter");
-  JsConstValueList params;
-  params.push_back(shared_from_this());
-  return func->Call(params)->AsBool();

[sergei, 2017/03/23 19:46:06]

There is actually `JsValue::Call(const JsValue& arg)` what about changing in the
same commit the call of the function, `func->Call(*this)->AsBool();`?

It's also valid for many cases below.

[hub, 2017/03/24 13:45:15]

Now that I'm looking at it, I think that this function should even be changed to
take a const JsConstValuePtr& so that we don't have to unwrap and reallocate a
new JsValue. And replacing all these calls where params has only one element.

[sergei, 2017/03/24 13:56:47]

We don't need to reallocate new JsValue here.

Actually I would like to reduce the number of cases when we use
std::shared_ptr<JsValue> and rather just use JsValue. So, we could add a helper
Call method accepting `const JsConstValuePtr&` but I would like to try without
it and actually see whether we need it.

[hub, 2017/03/24 14:08:03]

In JsValue::Call() we currently do:

params.push_back(JsValuePtr(new JsValue(arg.jsEngine, arg.UnwrapValue())));

Basically UnwrapValue() from const to a new value that we insert.

If we pass a JsConstValuePtr, we no longer need to do that.

[sergei, 2017/03/24 14:24:55]

I think that we should simply change the implementation of JsValue::Call(const
JsValue&) to don't create new JsValue and JsValuePtr. Finally I would like to
get rid of JsValuePtr because on practice there is no need for it.

[hub, 2017/03/24 16:05:06]

Agreed. Issue 3589?

[sergei, 2017/03/24 16:27:52]

I think it should be another issue (https://issues.adblockplus.org/ticket/5034)
and #3589 should be a part of it. So basically changing to `func->Call(*this)`
should be done as #5034.

+  return func->Call(shared_from_this())->AsBool();
 }
 
 void Filter::AddToList()
 {
   JsValuePtr func = jsEngine->Evaluate("API.addFilterToList");
-  JsConstValueList params;
-  params.push_back(shared_from_this());
-  func->Call(params);
+  func->Call(shared_from_this());
 }
 
 void Filter::RemoveFromList()
 {
   JsValuePtr func = jsEngine->Evaluate("API.removeFilterFromList");
-  JsConstValueList params;
-  params.push_back(shared_from_this());
-  func->Call(params);
+  func->Call(shared_from_this());
 }
 
 bool Filter::operator==(const Filter& filter) const
 {
   return GetProperty("text")->AsString() == filter.GetProperty("text")->AsString();
 }
 
 Subscription::Subscription(JsValue&& value)
     : JsValue(std::move(value))
 {
   if (!IsObject())
     throw std::runtime_error("JavaScript value is not an object");
 }
 
 bool Subscription::IsListed() const
 {
   JsValuePtr func = jsEngine->Evaluate("API.isListedSubscription");
-  JsConstValueList params;
-  params.push_back(shared_from_this());
-  return func->Call(params)->AsBool();
+  return func->Call(shared_from_this())->AsBool();
 }
 
 void Subscription::AddToList()
 {
   JsValuePtr func = jsEngine->Evaluate("API.addSubscriptionToList");
-  JsConstValueList params;
-  params.push_back(shared_from_this());
-  func->Call(params);
+  func->Call(shared_from_this());
 }
 
 void Subscription::RemoveFromList()
 {
   JsValuePtr func = jsEngine->Evaluate("API.removeSubscriptionFromList");
-  JsConstValueList params;
-  params.push_back(shared_from_this());
-  func->Call(params);
+  func->Call(shared_from_this());
 }
 
 void Subscription::UpdateFilters()
 {
   JsValuePtr func = jsEngine->Evaluate("API.updateSubscription");
-  JsConstValueList params;
-  params.push_back(shared_from_this());
-  func->Call(params);
+  func->Call(shared_from_this());
 }
 
 bool Subscription::IsUpdating() const
 {
   JsValuePtr func = jsEngine->Evaluate("API.isSubscriptionUpdating");
-  JsConstValueList params;
-  params.push_back(shared_from_this());
-  JsValuePtr result = func->Call(params);
+  JsValuePtr result = func->Call(shared_from_this());
   return result->AsBool();
 }
 
 bool Subscription::operator==(const Subscription& subscription) const
 {
   return GetProperty("url")->AsString() == subscription.GetProperty("url")->AsString();
 }
 
 namespace
 {
@@ skipping 127 matching lines @@
   ContentTypeMap::const_iterator it = contentTypes.find(contentType);
   if (it != contentTypes.end())
     return it->second;
   throw std::invalid_argument("Argument is not a valid ContentType");
 }
 
 FilterEngine::ContentType FilterEngine::StringToContentType(const std::string& contentType)
 {
   std::string contentTypeUpper = contentType;
   std::transform(contentType.begin(), contentType.end(), contentTypeUpper.begin(), ::toupper);
-  for (ContentTypeMap::const_iterator it = contentTypes.begin();
-       it != contentTypes.end(); it++)
-  {
-    if (it->second == contentTypeUpper)
-      return it->first;
+  for (const auto& contentType : contentTypes)
+  {
+    if (contentType.second == contentTypeUpper)
+      return contentType.first;
   }
   throw std::invalid_argument("Cannot convert argument to ContentType");
 }
 
 bool FilterEngine::IsFirstRun() const
 {
   return firstRun;
 }
 
 FilterPtr FilterEngine::GetFilter(const std::string& text) const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getFilterFromText");
-  JsConstValueList params;
-  params.push_back(jsEngine->NewValue(text));
-  return FilterPtr(new Filter(std::move(*func->Call(params))));
+  return FilterPtr(new Filter(std::move(*func->Call(jsEngine->NewValue(text)))));
 }
 
 SubscriptionPtr FilterEngine::GetSubscription(const std::string& url) const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getSubscriptionFromUrl");
-  JsConstValueList params;
-  params.push_back(jsEngine->NewValue(url));
-  return SubscriptionPtr(new Subscription(std::move(*func->Call(params))));
+  return SubscriptionPtr(new Subscription(std::move(*func->Call(jsEngine->NewValue(url)))));
 }
 
 std::vector<FilterPtr> FilterEngine::GetListedFilters() const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getListedFilters");
   JsValueList values = func->Call()->AsList();
   std::vector<FilterPtr> result;
   for (JsValueList::iterator it = values.begin(); it != values.end(); it++)
     result.push_back(FilterPtr(new Filter(std::move(**it))));
   return result;
@@ skipping 55 matching lines @@
 }
 
 AdblockPlus::FilterPtr FilterEngine::Matches(const std::string& url,
     ContentTypeMask contentTypeMask,
     const std::vector<std::string>& documentUrls) const
 {
   if (documentUrls.empty())
     return CheckFilterMatch(url, contentTypeMask, "");
 
   std::string lastDocumentUrl = documentUrls.front();
-  for (std::vector<std::string>::const_iterator it = documentUrls.begin();
-       it != documentUrls.end(); it++) {
-    const std::string documentUrl = *it;
+  for (const auto& documentUrl : documentUrls) {
     AdblockPlus::FilterPtr match = CheckFilterMatch(documentUrl,
                                                     CONTENT_TYPE_DOCUMENT,
                                                     lastDocumentUrl);
     if (match && match->GetType() == AdblockPlus::Filter::TYPE_EXCEPTION)
       return match;
     lastDocumentUrl = documentUrl;
   }
 
   return CheckFilterMatch(url, contentTypeMask, lastDocumentUrl);
 }
@@ skipping 22 matching lines @@
   JsValuePtr result = func->Call(params);
   if (!result->IsNull())
     return FilterPtr(new Filter(std::move(*result)));
   else
     return FilterPtr();
 }
 
 std::vector<std::string> FilterEngine::GetElementHidingSelectors(const std::string& domain) const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getElementHidingSelectors");
-  JsConstValueList params;
-  params.push_back(jsEngine->NewValue(domain));
-  JsValueList result = func->Call(params)->AsList();
+  JsValueList result = func->Call(jsEngine->NewValue(domain))->AsList();
   std::vector<std::string> selectors;
-  for (JsValueList::iterator it = result.begin(); it != result.end(); ++it)
-    selectors.push_back((*it)->AsString());
+  for (const auto& r: result)
+    selectors.push_back(r->AsString());
   return selectors;
 }
 
 JsValuePtr FilterEngine::GetPref(const std::string& pref) const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getPref");
-  JsConstValueList params;
-  params.push_back(jsEngine->NewValue(pref));
-  return func->Call(params);
+  return func->Call(jsEngine->NewValue(pref));
 }
 
 void FilterEngine::SetPref(const std::string& pref, JsValuePtr value)
 {
   JsValuePtr func = jsEngine->Evaluate("API.setPref");
   JsConstValueList params;
   params.push_back(jsEngine->NewValue(pref));
   if (value)
     params.push_back(value);
   func->Call(params);
 }
 
 std::string FilterEngine::GetHostFromURL(const std::string& url) const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getHostFromUrl");
-  JsConstValueList params;
-  params.push_back(jsEngine->NewValue(url));
-  return func->Call(params)->AsString();
+  return func->Call(jsEngine->NewValue(url))->AsString();
 }
 
 void FilterEngine::SetUpdateAvailableCallback(
     FilterEngine::UpdateAvailableCallback callback)
 {
   jsEngine->SetEventCallback("updateAvailable",
       std::bind(&FilterEngine::UpdateAvailable, this, callback,
                 std::placeholders::_1));
 }
 
@@ skipping 115 matching lines @@
     FilterPtr filter = GetWhitelistingFilter(currentUrl, contentTypeMask, parentUrl);
     if (filter)
     {
       return filter;
     }
     currentUrl = parentUrl;
   }
   while (urlIterator != documentUrls.end());
   return FilterPtr();
 }