PR doxygen#11631 refactor: use lookup instead of linear search

Author: doxygen

src/docnode.cpp

@@ -759,16 +759,14 @@ DocRef::DocRef(DocParser *parser,DocNodeVariant *parent,const QCString &target,c
   }
   else if (Config_getBool(IMPLICIT_DIR_DOCS) && target.lower().endsWith("/readme.md"))
   {
-    QCString dirTarget = target.left(target.length() - 9);
-    for (const auto &dd : *Doxygen::dirLinkedMap)
+    QCString dirTarget = target.left(target.length() - 9); // strip readme.md part
+    const auto &dd = Doxygen::dirLinkedMap->find(dirTarget);
+    if (dd)
     {
-      if (dd->name() == dirTarget)
-      {
-        m_text = target;
-        m_file = dd->getOutputFileBase();
-        AUTO_TRACE_EXIT("directory");
-        return;
-      }
+      m_text = target;
+      m_file = dd->getOutputFileBase();
+      AUTO_TRACE_EXIT("directory");
+      return;
     }
   }
   else if (resolveLink(context,target,true,&compound,anchor,lang,parser->context.prefix))