Issue 4931 - add possibility to not send data depending on connection properties

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 160 matching lines @@
   : jsEngine(jsEngine), firstRun(false), updateCheckId(0)
 {
 }
 
 void FilterEngine::CreateAsync(const JsEnginePtr& jsEngine,
   const FilterEngine::OnCreatedCallback& onCreated,
   const FilterEngine::CreateParameters& params)
 {
   FilterEnginePtr filterEngine(new FilterEngine(jsEngine));
   auto sync = std::make_shared<Sync>();
-  jsEngine->SetEventCallback("_init", [jsEngine, filterEngine, onCreated, sync](JsValueList& params)
+  auto isConnectionAllowedCallback = params.isConnectionAllowedCallback;
+  if (isConnectionAllowedCallback)
+    jsEngine->SetIsConnectionAllowedCallback([sync, jsEngine]()->bool
+    {
+      sync->Wait();
+      return jsEngine->IsConnectionAllowed();
+    });
+  jsEngine->SetEventCallback("_init", [jsEngine, filterEngine, onCreated, sync, isConnectionAllowedCallback](JsValueList& params)
   {
     filterEngine->firstRun = params.size() && params[0]->AsBool();
+    if (isConnectionAllowedCallback)
+    {
+      std::weak_ptr<FilterEngine> weakFilterEngine = filterEngine;
+      jsEngine->SetIsConnectionAllowedCallback([weakFilterEngine, isConnectionAllowedCallback]()->bool
+      {
+        auto filterEngine = weakFilterEngine.lock();
+        if (!filterEngine)
+          return false;
+        return isConnectionAllowedCallback(filterEngine->GetAllowedConnectionType().get());
+      });
+    }
     sync->Set();
     onCreated(filterEngine);
     jsEngine->RemoveEventCallback("_init");
   });
 
   // Lock the JS engine while we are loading scripts, no timeouts should fire
   // until we are done.
   const JsContext context(jsEngine);
 
   // Set the preconfigured prefs
@@ skipping 226 matching lines @@
   JsValueList params;
   params.push_back(jsEngine->NewValue(pref));
   return func->Call(params);
 }
 
 void FilterEngine::SetPref(const std::string& pref, JsValuePtr value)
 {
   JsValuePtr func = jsEngine->Evaluate("API.setPref");
   JsValueList params;
   params.push_back(jsEngine->NewValue(pref));
-  params.push_back(value);
+  if (value)
+    params.push_back(value);
   func->Call(params);
 }
 
 std::string FilterEngine::GetHostFromURL(const std::string& url)
 {
   JsValuePtr func = jsEngine->Evaluate("API.getHostFromUrl");
   JsValueList params;
   params.push_back(jsEngine->NewValue(url));
   return func->Call(params)->AsString();
 }
@@ skipping 46 matching lines @@
 {
   jsEngine->SetEventCallback("filterChange", std::bind(&FilterEngine::FilterChanged,
       this, callback, std::placeholders::_1));
 }
 
 void FilterEngine::RemoveFilterChangeCallback()
 {
   jsEngine->RemoveEventCallback("filterChange");
 }
 
+void FilterEngine::SetAllowedConnectionType(const std::string* value)
+{
+  SetPref("allowed_connection_type", value ? jsEngine->NewValue(*value) : nullptr);
+}
+
+std::unique_ptr<std::string> FilterEngine::GetAllowedConnectionType()
+{
+   auto prefValue = GetPref("allowed_connection_type");
+   if (prefValue->IsUndefined())
+     return nullptr;
+   return std::unique_ptr<std::string>(new std::string(prefValue->AsString()));
+}
+
 void FilterEngine::FilterChanged(FilterEngine::FilterChangeCallback callback, JsValueList& params)
 {
   std::string action(params.size() >= 1 && !params[0]->IsNull() ? params[0]->AsString() : "");
   JsValuePtr item(params.size() >= 2 ? params[1] : jsEngine->NewValue(false));
   callback(action, item);
 }
 
 void FilterEngine::ShowNotification(const ShowNotificationCallback& callback,
                                          const JsValueList& params)
 {
@@ skipping 45 matching lines @@
     FilterPtr filter = GetWhitelistingFilter(currentUrl, contentTypeMask, parentUrl);
     if (filter)
     {
       return filter;
     }
     currentUrl = parentUrl;
   }
   while (urlIterator != documentUrls.end());
   return FilterPtr();
 }