From a96fd62d0363af38ae6574eeaf1846b818669d8c Mon Sep 17 00:00:00 2001
From: theoreticalbts <theoreticalbts@users.noreply.github.com>
Date: Thu, 5 Nov 2015 14:56:59 -0500
Subject: [PATCH] fee_schedule.cpp:  Use relaxation to set fee #435

---
 libraries/chain/protocol/fee_schedule.cpp | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/libraries/chain/protocol/fee_schedule.cpp b/libraries/chain/protocol/fee_schedule.cpp
index 6950aac0..6a8fc11f 100644
--- a/libraries/chain/protocol/fee_schedule.cpp
+++ b/libraries/chain/protocol/fee_schedule.cpp
@@ -31,6 +31,8 @@ namespace fc
    //template const graphene::chain::fee_schedule& smart_ref<graphene::chain::fee_schedule>::operator*() const;
 }
 
+#define MAX_FEE_STABILIZATION_ITERATION 4
+
 namespace graphene { namespace chain {
 
    typedef fc::smart_ref<fee_schedule> smart_fee_schedule;
@@ -138,8 +140,23 @@ namespace graphene { namespace chain {
    asset fee_schedule::set_fee( operation& op, const price& core_exchange_rate )const
    {
       auto f = calculate_fee( op, core_exchange_rate );
-      op.visit( set_fee_visitor( f ) );
-      return f;
+      auto f_max = f;
+      for( int i=0; i<MAX_FEE_STABILIZATION_ITERATION; i++ )
+      {
+         op.visit( set_fee_visitor( f_max ) );
+         auto f2 = calculate_fee( op, core_exchange_rate );
+         if( f == f2 )
+            break;
+         f_max = std::max( f_max, f2 );
+         f = f2;
+         if( i == 0 )
+         {
+            // no need for warnings on later iterations
+            wlog( "set_fee requires multiple iterations to stabilize with core_exchange_rate ${p} on operation ${op}",
+               ("p", core_exchange_rate) ("op", op) );
+         }
+      }
+      return f_max;
    }
 
    void chain_parameters::validate()const