Resolve #161: Fix account creation fee scaling

libraries/chain/account_evaluator.cpp

@@ -107,13 +107,12 @@ object_id_type account_create_evaluator::do_apply( const account_create_operatio
       ++p.accounts_registered_this_interval;
    });
 
-   /** TODO: update fee scaling for account creation...
+   const auto& global_properties = db().get_global_properties();
    if( dynamic_properties.accounts_registered_this_interval %
        global_properties.parameters.accounts_per_fee_scale == 0 )
       db().modify(global_properties, [&dynamic_properties](global_property_object& p) {
-         p.parameters.current_fees.account_create_fee <<= p.parameters.account_fee_scale_bitshifts;
+         p.parameters.current_fees->get<account_create_operation>().basic_fee <<= p.parameters.account_fee_scale_bitshifts;
       });
-   */
 
    return new_acnt_object.id;
 } FC_CAPTURE_AND_RETHROW((o)) }

libraries/chain/db_maint.cpp

@@ -461,12 +461,9 @@ void database::perform_chain_maintenance(const signed_block& next_block, const g
 
    modify(gpo, [this](global_property_object& p) {
       // Remove scaling of account registration fee
-     /*
-      /// TODO reimplement this 
       const auto& dgpo = get_dynamic_global_properties();
-      p.parameters.current_fees.account_create_fee >>= p.parameters.account_fee_scale_bitshifts *
+      p.parameters.current_fees->get<account_create_operation>().basic_fee >>= p.parameters.account_fee_scale_bitshifts *
             (dgpo.accounts_registered_this_interval / p.parameters.accounts_per_fee_scale);
-     */
 
       if( p.pending_parameters )
       {

libraries/chain/include/graphene/chain/protocol/fee_schedule.hpp

@@ -5,7 +5,7 @@ namespace graphene { namespace chain {
 
    template<typename T> struct transform_to_fee_parameters;
    template<typename ...T>
-   struct transform_to_fee_parameters<fc::static_variant<T...>> 
+   struct transform_to_fee_parameters<fc::static_variant<T...>>
    {
       typedef fc::static_variant< typename T::fee_parameters_type... > type;
    };
@@ -21,7 +21,7 @@ namespace graphene { namespace chain {
       static fee_schedule get_default();
 
       /**
-       *  Finds the appropriate fee parameter struct for the operation 
+       *  Finds the appropriate fee parameter struct for the operation
        *  and then calculates the appropriate fee.
        */
       asset calculate_fee( const operation& op, const price& core_exchange_rate = price::unit_price() )const;
@@ -41,6 +41,13 @@ namespace graphene { namespace chain {
          FC_ASSERT( itr != parameters.end() );
          return itr->template get<typename Operation::fee_parameters_type>();
       }
+      template<typename Operation>
+      typename Operation::fee_parameters_type& get()
+      {
+         auto itr = parameters.find( typename Operation::fee_parameters_type() );
+         FC_ASSERT( itr != parameters.end() );
+         return itr->template get<typename Operation::fee_parameters_type>();
+      }
 
       /**
        *  @note must be sorted by fee_parameters.which() and have no duplicates
@@ -51,7 +58,7 @@ namespace graphene { namespace chain {
 
    typedef fee_schedule fee_schedule_type;
 
-} } // graphene::chain 
+} } // graphene::chain
 
 FC_REFLECT_TYPENAME( graphene::chain::fee_parameters )
 FC_REFLECT( graphene::chain::fee_schedule, (parameters)(scale) )

tests/common/database_fixture.cpp

@@ -822,7 +822,7 @@ void database_fixture::enable_fees()
    db.modify(global_property_id_type()(db), [](global_property_object& gpo)
    {
       gpo.parameters.current_fees = fee_schedule::get_default();
-   } );
+   });
 }
 
 void database_fixture::upgrade_to_lifetime_member(account_id_type account)

tests/tests/block_tests.cpp

@@ -680,7 +680,7 @@ BOOST_FIXTURE_TEST_CASE( double_sign_check, database_fixture )
    t.to = alice.id;
    t.amount = amount;
    trx.operations.push_back(t);
-   for( auto& op : trx.operations ) db.current_fee_schedule().set_fee(op); 
+   for( auto& op : trx.operations ) db.current_fee_schedule().set_fee(op);
    trx.validate();
 
    BOOST_TEST_MESSAGE( "Verify that not-signing causes an exception" );
@@ -967,4 +967,31 @@ BOOST_FIXTURE_TEST_CASE( rsf_missed_blocks, database_fixture )
    FC_LOG_AND_RETHROW()
 }
 
+BOOST_FIXTURE_TEST_CASE( account_create_fee_scaling, database_fixture )
+{ try {
+   auto accounts_per_scale = db.get_global_properties().parameters.accounts_per_fee_scale;
+   db.modify(global_property_id_type()(db), [](global_property_object& gpo)
+   {
+      gpo.parameters.current_fees = fee_schedule::get_default();
+      gpo.parameters.current_fees->get<account_create_operation>().basic_fee = 1;
+   });
+
+   BOOST_CHECK_EQUAL(db.get_global_properties().parameters.current_fees->get<account_create_operation>().basic_fee, 1);
+   for( int i = db.get_dynamic_global_properties().accounts_registered_this_interval; i < accounts_per_scale; ++i )
+      create_account("shill" + fc::to_string(i));
+   generate_block();
+   BOOST_CHECK_EQUAL(db.get_global_properties().parameters.current_fees->get<account_create_operation>().basic_fee, 16);
+   for( int i = 0; i < accounts_per_scale; ++i )
+      create_account("moreshills" + fc::to_string(i));
+   generate_block();
+   BOOST_CHECK_EQUAL(db.get_global_properties().parameters.current_fees->get<account_create_operation>().basic_fee, 256);
+   for( int i = 0; i < accounts_per_scale; ++i )
+      create_account("moarshills" + fc::to_string(i));
+   generate_block();
+   BOOST_CHECK_EQUAL(db.get_global_properties().parameters.current_fees->get<account_create_operation>().basic_fee, 4096);
+
+   generate_blocks(db.get_dynamic_global_properties().next_maintenance_time);
+   BOOST_CHECK_EQUAL(db.get_global_properties().parameters.current_fees->get<account_create_operation>().basic_fee, 1);
+} FC_LOG_AND_RETHROW() }
+
 BOOST_AUTO_TEST_SUITE_END()