EEI: charge for memory gas cost in useGas

Author: axic

src/eei.cpp

@@ -132,6 +132,8 @@ namespace hera {
       ensureCondition(gas >= 0, ArgumentOutOfRange, "Negative gas supplied.");
 
       takeGas(gas);
+      // FIXME: this may overflow
+      takeGas(gas * memory.size() / GasSchedule::memoryPageSize * GasSchedule::memoryCostPerPage);
   }
 
   int64_t EthereumInterface::eeiGetGasLeft()

src/eei.h

@@ -163,6 +163,9 @@ class EthereumInterface {
 };
 
 struct GasSchedule {
+  static constexpr unsigned memoryPageSize = 65536;
+  static constexpr unsigned memoryCostPerPage = 1;
+
   static constexpr unsigned storageLoad = 200;
   static constexpr unsigned storageStoreCreate = 20000;
   static constexpr unsigned storageStoreChange = 5000;