Issue 1550 - Get rid of V8ValueHolder.h

src/FilterEngine.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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 10 matching lines @@
 #include <string>
 
 #include <AdblockPlus.h>
 #include "JsContext.h"
 #include "Thread.h"
 
 using namespace AdblockPlus;
 
 extern std::string jsSources[];
 
-Filter::Filter(JsValuePtr value)
-    : JsValue(value)
+Filter::Filter(JsValue&& value)
+    : JsValue(std::move(value))
 {
   if (!IsObject())
     throw std::runtime_error("JavaScript value is not an object");
 }
 
 Filter::Type Filter::GetType()
 {
   std::string className = GetClass();
   if (className == "BlockingFilter")
     return TYPE_BLOCKING;
@@ skipping 31 matching lines @@
   JsValueList params;
   params.push_back(shared_from_this());
   func->Call(params);
 }
 
 bool Filter::operator==(const Filter& filter) const
 {
   return GetProperty("text")->AsString() == filter.GetProperty("text")->AsString();
 }
 
-Subscription::Subscription(JsValuePtr value)
-    : JsValue(value)
+Subscription::Subscription(JsValue&& value)
+    : JsValue(std::move(value))
 {
   if (!IsObject())
     throw std::runtime_error("JavaScript value is not an object");
 }
 
 bool Subscription::IsListed()
 {
   JsValuePtr func = jsEngine->Evaluate("API.isListedSubscription");
   JsValueList params;
   params.push_back(shared_from_this());
@@ skipping 124 matching lines @@
 bool FilterEngine::IsFirstRun() const
 {
   return firstRun;
 }
 
 FilterPtr FilterEngine::GetFilter(const std::string& text)
 {
   JsValuePtr func = jsEngine->Evaluate("API.getFilterFromText");
   JsValueList params;
   params.push_back(jsEngine->NewValue(text));
-  return FilterPtr(new Filter(func->Call(params)));
+  return FilterPtr(new Filter(std::move(*func->Call(params))));

[Eric, 2016/01/26 18:37:40]

Why is 'move' necessary here? The value is already temporary.

[sergei, 2016/01/27 10:21:14]

Compiler generates an error here because it's not temporary. `Call` returns
std::shared_ptr<AdblockPlus::JsValue>, dereferencing of it gives a reference to
the held object.

Strictly speaking, `Call` should return rather `JsValue` (which is temporary and
JsValue&&) instead of std::shared_ptr but it introduces a lot of non-relevant
changes which IMO should be made in another commit.

[sergei, 2016/01/27 11:23:02]

FYI: https://codereview.adblockplus.org/29334678/

[Eric, 2016/02/08 19:50:06]

That change set belongs here. You're adding a bunch of 'std::move' calls here
and then immediately taking them out again. That's should really be an indicator
that the changes are closely related.

[Eric, 2016/02/08 19:50:06]

OK.

 }
 
 SubscriptionPtr FilterEngine::GetSubscription(const std::string& url)
 {
   JsValuePtr func = jsEngine->Evaluate("API.getSubscriptionFromUrl");
   JsValueList params;
   params.push_back(jsEngine->NewValue(url));
-  return SubscriptionPtr(new Subscription(func->Call(params)));
+  return SubscriptionPtr(new Subscription(std::move(*func->Call(params))));
 }
 
 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(*it)));
+    result.push_back(FilterPtr(new Filter(std::move(**it))));
   return result;
 }
 
 std::vector<SubscriptionPtr> FilterEngine::GetListedSubscriptions() const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getListedSubscriptions");
   JsValueList values = func->Call()->AsList();
   std::vector<SubscriptionPtr> result;
   for (JsValueList::iterator it = values.begin(); it != values.end(); it++)
-    result.push_back(SubscriptionPtr(new Subscription(*it)));
+    result.push_back(SubscriptionPtr(new Subscription(std::move(**it))));
   return result;
 }
 
 std::vector<SubscriptionPtr> FilterEngine::FetchAvailableSubscriptions() const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getRecommendedSubscriptions");
   JsValueList values = func->Call()->AsList();
   std::vector<SubscriptionPtr> result;
   for (JsValueList::iterator it = values.begin(); it != values.end(); it++)
-    result.push_back(SubscriptionPtr(new Subscription(*it)));
+    result.push_back(SubscriptionPtr(new Subscription(std::move(**it))));
   return result;
 }
 
 void FilterEngine::ShowNextNotification(const std::string& url)
 {
   JsValuePtr func = jsEngine->Evaluate("API.showNextNotification");
   JsValueList params;
   if (!url.empty())
   {
     params.push_back(jsEngine->NewValue(url));
@@ skipping 63 matching lines @@
     ContentType contentType,
     const std::string& documentUrl) const
 {
   JsValuePtr func = jsEngine->Evaluate("API.checkFilterMatch");
   JsValueList params;
   params.push_back(jsEngine->NewValue(url));
   params.push_back(jsEngine->NewValue(ContentTypeToString(contentType)));
   params.push_back(jsEngine->NewValue(documentUrl));
   JsValuePtr result = func->Call(params);
   if (!result->IsNull())
-    return FilterPtr(new Filter(result));
+    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");
   JsValueList params;
   params.push_back(jsEngine->NewValue(domain));
   JsValueList result = func->Call(params)->AsList();
@@ skipping 93 matching lines @@
 void FilterEngine::ShowNotification(const ShowNotificationCallback& callback,
                                          const JsValueList& params)
 {
   if (params.size() < 1)
     return;
 
   if (!params[0]->IsObject())
   {
     return;
   }
-  callback(NotificationPtr(new Notification(params[0])));
+  callback(NotificationPtr(new Notification(std::move(*params[0]))));
 }
 
 
 int FilterEngine::CompareVersions(const std::string& v1, const std::string& v2)
 {
   JsValueList params;
   params.push_back(jsEngine->NewValue(v1));
   params.push_back(jsEngine->NewValue(v2));
   JsValuePtr func = jsEngine->Evaluate("API.compareVersions");
   return func->Call(params)->AsInt();
@@ skipping 28 matching lines @@
                          currentUrl, contentType, parentUrl);
     if (filter)
     {
       return filter;
     }
     currentUrl = parentUrl;
   }
   while (urlIterator != documentUrls.end());
   return FilterPtr();
 }