core,state: finish implementing Eip 1283

Author: holiman

core/state/state_object.go

@@ -183,6 +183,16 @@ func (self *stateObject) GetState(db Database, key common.Hash) common.Hash {
 	return value
 }
 
+// GetOriginalStateValue returns the state value that is currently in the Trie, that is, ignoring any
+// changes that have been made but not yet written to trie.
+func (self *stateObject) GetOriginalStateValue(db Database, key common.Hash) common.Hash{
+	if original, exist:= self.originalValue[key]; exist {
+		// original value has been set, return it
+		return original
+	}
+	return self.GetState(db, key)
+}
+
 // SetState updates a value in account storage.
 func (self *stateObject) SetState(db Database, key, value common.Hash) {
 	prev := self.GetState(db, key)

core/state/statedb.go

@@ -255,6 +255,14 @@ func (self *StateDB) GetState(addr common.Address, bhash common.Hash) common.Has
 	return common.Hash{}
 }
 
+func (self *StateDB) GetStateOriginal(addr common.Address, bhash common.Hash) common.Hash {
+	stateObject := self.getStateObject(addr)
+	if stateObject != nil {
+		return stateObject.GetOriginalStateValue(self.db, bhash)
+	}
+	return common.Hash{}
+}
+
 // Database retrieves the low level database supporting the lower level trie ops.
 func (self *StateDB) Database() Database {
 	return self.db

core/vm/gas_table.go

@@ -17,11 +17,9 @@
 package vm
 
 import (
-	"bytes"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/params"
-	"math/big"
 )
 
 // memoryGasCosts calculates the quadratic gas for memory expansion. It does so
@@ -117,7 +115,7 @@ func gasReturnDataCopy(gt params.GasTable, evm *EVM, contract *Contract, stack *
 	return gas, nil
 }
 
-func gasSStoreOld(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+func gasSStore(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
 	var (
 		y, x = stack.Back(1), stack.Back(0)
 		val  = evm.StateDB.GetState(contract.Address(), common.BigToHash(x))
@@ -139,10 +137,11 @@ func gasSStoreOld(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack
 	}
 }
 
-func gasSStore(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+// gasSStoreEip1283 calculates SSTORE gas cost according to EIP-1283
+func gasSStoreEip1283(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
 	var (
-		y, x = stack.Back(1), stack.Back(0)
-		current  = evm.StateDB.GetState(contract.Address(), common.BigToHash(x))
+		y, x    = stack.Back(1), stack.Back(0)
+		current = evm.StateDB.GetState(contract.Address(), common.BigToHash(x))
 	)
 	//1. If current value equals new value (this is a no-op), 200 gas is deducted.
 	//2. If current value does not equal new value
@@ -161,33 +160,31 @@ func gasSStore(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, m
 		// 1. current == new
 		return 200, nil
 	}
-	// Todo, get this value
-	original := common.Hash{}
-
+	original := evm.StateDB.GetStateOriginal(contract.Address(), common.BigToHash(x))
 	// 2
 	if original == current { // 2.1
-		if original == (common.Hash{}){ // 2.1.1
+		if original == (common.Hash{}) { // 2.1.1
 			return 20000, nil
 		}
 		// 2.1.2
-		if new == (common.Hash{}){
+		if new == (common.Hash{}) {
 			evm.StateDB.AddRefund(15000)
 		}
 		return 5000, nil
 	}
 	// 2.2
-	if original != (common.Hash{}){ // 2.2.1
-		if current == (common.Hash{}){ // 2.2.1.1
+	if original != (common.Hash{}) { // 2.2.1
+		if current == (common.Hash{}) { // 2.2.1.1
 			evm.StateDB.SubRefund(15000)
-		}else{
+		} else {
 			// 2.2.1.2
 			evm.StateDB.AddRefund(15000)
 		}
 	}
 	if original == new { // 2.2.2
-		if original == (common.Hash{}){
+		if original == (common.Hash{}) {
 			evm.StateDB.AddRefund(19800)
-		}else{
+		} else {
 			evm.StateDB.AddRefund(4800)
 		}
 	}

core/vm/interface.go

@@ -44,6 +44,7 @@ type StateDB interface {
 	GetRefund() uint64
 
 	GetState(common.Address, common.Hash) common.Hash
+	GetStateOriginal(common.Address, common.Hash) common.Hash
 	SetState(common.Address, common.Hash, common.Hash)
 
 	Suicide(common.Address) bool

core/vm/jump_table.go

@@ -95,6 +95,14 @@ func newConstantinopleInstructionSet() [256]operation {
 		writes:        true,
 		returns:       true,
 	}
+	instructionSet[SSTORE] = operation{
+		execute:       opSstore,
+		gasCost:       gasSStoreEip1283,
+		validateStack: makeStackFunc(2, 0),
+		valid:         true,
+		writes:        true,
+	}
+
 	return instructionSet
 }
 

core/vm/noop.go

@@ -59,6 +59,7 @@ func (NoopStateDB) AddRefund(uint64)
 func (NoopStateDB) SubRefund(uint64)                                                   {}
 func (NoopStateDB) GetRefund() uint64                                                  { return 0 }
 func (NoopStateDB) GetState(common.Address, common.Hash) common.Hash                   { return common.Hash{} }
+func (NoopStateDB) GetStateOriginal(common.Address, common.Hash) common.Hash           { return common.Hash{} }
 func (NoopStateDB) SetState(common.Address, common.Hash, common.Hash)                  {}
 func (NoopStateDB) Suicide(common.Address) bool                                        { return false }
 func (NoopStateDB) HasSuicided(common.Address) bool                                    { return false }