Replace scan to a child process

src/usermanager.h

@@ -4,6 +4,7 @@
 #include <string>
 #include <map>
 #include <vector>
+#include <set>
 #include <sstream>
 #include <mutex>
 #include "locations.h"
@@ -71,23 +72,23 @@ public:
         }
     }
 
-    std::vector<std::string> getUsers()
+    std::set<std::string> getUsers()
     {
-        std::vector<std::string> ret;
+        std::set<std::string> ret;
 
         std::lock_guard<std::mutex> lock(mtx);
 
         for (std::map<std::string, bool>::iterator it = users.begin(); it != users.end(); ++it)
         {
-            ret.push_back(it->first);
+            ret.insert(it->first);
         }
 
         return ret;
     }
 
-    std::vector<std::string> getFlaggedUsers()
+    std::set<std::string> getFlaggedUsers()
     {
-        std::vector<std::string> ret;
+        std::set<std::string> ret;
 
         std::lock_guard<std::mutex> lock(mtx);
 
@@ -95,14 +96,14 @@ public:
         {
             if (it->second)
             {
-                ret.push_back(it->first);
+                ret.insert(it->first);
             }
         }
 
         return ret;
     }
 
-    bool isAnybodyInQueue()
+    bool isAnybodyFlagged()
     {
         std::lock_guard<std::mutex> lock(mtx);