GasMeter is an object now (#73)

nimbus/vm/computation.nim

@@ -18,7 +18,7 @@ proc newBaseComputation*(vmState: BaseVMState, blockNumber: UInt256, message: Me
   result.msg = message
   result.memory = Memory()
   result.stack = newStack()
-  result.gasMeter = newGasMeter(message.gas)
+  result.gasMeter.init(message.gas)
   result.children = @[]
   result.accountsToDelete = initTable[EthAddress, EthAddress]()
   result.logEntries = @[]

nimbus/vm/interpreter/gas_meter.nim

@@ -9,12 +9,11 @@ import
   strformat, eth_common, # GasInt
   ../../logging, ../../errors, ../../vm_types
 
-proc newGasMeter*(startGas: GasInt): GasMeter =
-  new(result)
-  result.startGas = startGas
-  result.gasRemaining = result.startGas
-  result.gasRefunded = 0
-  result.logger = logging.getLogger("gas")
+proc init*(m: var GasMeter, startGas: GasInt) =
+  m.startGas = startGas
+  m.gasRemaining = m.startGas
+  m.gasRefunded = 0
+  m.logger = logging.getLogger("gas")
 
 proc consumeGas*(gasMeter: var GasMeter; amount: GasInt; reason: string) =
   #if amount < 0.u256:

nimbus/vm/interpreter/opcodes_impl.nim

@@ -565,7 +565,7 @@ op create, inline = false, value, startPosition, size:
   # let childComputation = applyChildBaseComputation(computation, childMsg)
   var childComputation: BaseComputation # TODO - stub
   new childComputation
-  childComputation.gasMeter = newGasMeter(0) # TODO GasMeter should be a normal object.
+  childComputation.gasMeter.init(0)
 
   if childComputation.isError:
     push: 0
@@ -739,7 +739,7 @@ template genCall(callName: untyped): untyped =
     # let childComputation = applyChildBaseComputation(computation, childMsg)
     var childComputation: BaseComputation # TODO - stub
     new childComputation
-    childComputation.gasMeter = newGasMeter(0) # TODO GasMeter should be a normal object.
+    childComputation.gasMeter.init(0)
 
     if childComputation.isError:
       push: 0

nimbus/vm_types.nim

@@ -45,7 +45,7 @@ type
     kind*: Op
     runLogic*:  proc(computation: var BaseComputation)
 
-  GasMeter* = ref object # TODO: use a normal object
+  GasMeter* = object
     logger*: Logger
     gasRefunded*: GasInt
     startGas*: GasInt

tests/test_gas_meter.nim

@@ -15,8 +15,10 @@ import
 
 # disableLogging()
 
+proc initGasMeter(startGas: GasInt): GasMeter = result.init(startGas)
+
 proc gasMeters: seq[GasMeter] =
-  @[newGasMeter(10), newGasMeter(100), newGasMeter(999)]
+  @[initGasMeter(10), initGasMeter(100), initGasMeter(999)]
 
 macro all(element: untyped, handler: untyped): untyped =
   let name = ident(&"{element.repr}s")