use invalid to record salt hit rate

conf/global.constant

@@ -5,4 +5,5 @@ useHOM:false
 useOPE:false
 useSWP:true
 useDET:false
+useSalt:true
 other:1

debug/final_load.cc

@@ -303,6 +303,7 @@ void local_wrapper(const Item &i, const FieldMeta &fm, Analysis &a,
                                 Item_int(static_cast<ulonglong>(valFromStr(in)))
              );
             tempFileVector.pop_back();
+            gcountMap[oINVALID]++;//use invalid to record the salt hit rate
         }else{
             l.push_back(new Item_int(static_cast<ulonglong>(salt)));
         }