Issue 1564-Fix FilterEngine::Matches for allowing request which is whitelisted in the ascendant node

src/ReferrerMapping.cpp

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <AdblockPlus/ReferrerMapping.h>
 
 using namespace AdblockPlus;
 
 ReferrerMapping::ReferrerMapping(const int maxCachedUrls)
   : maxCachedUrls(maxCachedUrls)
 {
 }
 
-void ReferrerMapping::Add(const std::string& url, const std::string& referrer)
+void ReferrerMapping::Add(const Url& url, const Url& referrer, FrameIndicator isFrame)
 {
   if (mapping.find(url) != mapping.end())
     cachedUrls.remove(url);
   cachedUrls.push_back(url);
-  mapping[url] = referrer;
+  mapping[url] = RequestInfo(referrer, isFrame);
 
   const int urlsToPop = cachedUrls.size() - maxCachedUrls;
   for (int i = 0; i < urlsToPop; i++)
   {
     const std::string poppedUrl = cachedUrls.front();
     cachedUrls.pop_front();
     mapping.erase(poppedUrl);
   }
 }
 
-std::vector<std::string> ReferrerMapping::BuildReferrerChain(
-  const std::string& url) const
+ReferrerMapping::Urls ReferrerMapping::BuildFrameStructure(const Url& url) const
 {
-  std::vector<std::string> referrerChain;
-  referrerChain.push_back(url);
+  Urls frames;
   // We need to limit the chain length to ensure we don't block indefinitely
   // if there's a referrer loop.
   const int maxChainLength = 10;
-  std::map<std::string, std::string>::const_iterator currentEntry =
-    mapping.find(url);
+  ReferrerMap::const_iterator currentEntry = mapping.end();
+  ReferrerMap::const_iterator prevEntry = mapping.end();
+  // process the current url beyond the loop below because we should add it

[Wladimir Palant, 2014/12/09 21:20:03]

beyond => outside

+  // even if `mapping` is empty.
+  if (!url.empty())
+  {
+    currentEntry = mapping.find(url);
+    if (currentEntry != mapping.end())
+    {
+      if (currentEntry->second.IsFrame())
+      {
+        frames.push_back(url);
+      }
+      prevEntry = currentEntry;
+      currentEntry = mapping.find(currentEntry->second.referrer);
+    }
+    else
+    {
+      // If there is no information for the url in `mapping` then assume that
+      // it's a frame, despite it's not necessary to be a frame.

[Wladimir Palant, 2014/12/09 21:20:03]

Nit: "despite it not necessarily being a frame"

+      frames.push_back(url);
+    }
+  }

[Wladimir Palant, 2014/12/09 21:20:03]

Can't we check prevEntry after the loop instead of duplicating its content?
Something along these lines:

  auto currentEntry = mapping.find(url);
  auto prevEntry = mapping.end();
  for (...)
  {
    ...
  }
  if (prevEntry == mapping.end())
  {
    // No data, just assume that the url is a frame.
    frames.push_back(url);
  }
  else if (!prevEntry->second.referrer.empty())
  {
    ...
  }

[sergei, 2014/12/12 17:07:07]

That does work, please check the updated version. Although I would say that the
complexity of the algorithm is higher despite the amount of code is less and
there is no repeating.

+
   for (int i = 0; i < maxChainLength && currentEntry != mapping.end(); i++)
   {
-    const std::string& currentUrl = currentEntry->second;
-    referrerChain.insert(referrerChain.begin(), currentUrl);
-    currentEntry = mapping.find(currentUrl);
+    if (currentEntry->second.IsFrame())
+    {
+      frames.insert(frames.begin(), currentEntry->first);
+    }
+    prevEntry = currentEntry;
+    currentEntry = mapping.find(currentEntry->second.referrer);
   }
-  return referrerChain;
+  if (prevEntry != mapping.end() && !prevEntry->second.referrer.empty())
+  {
+    frames.insert(frames.begin(), prevEntry->second.referrer);
+  }
+  return frames;
 }