diff options
Diffstat (limited to 'ethchain/vm.go')
| -rw-r--r-- | ethchain/vm.go | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/ethchain/vm.go b/ethchain/vm.go index 861b041d8..2fa78a748 100644 --- a/ethchain/vm.go +++ b/ethchain/vm.go @@ -18,6 +18,8 @@ type Vm struct { mem map[string]*big.Int vars RuntimeVars + + state *State } type RuntimeVars struct { @@ -32,7 +34,11 @@ type RuntimeVars struct { txData []string } -func (vm *Vm) RunClosure(closure *Closure, state *State, vars RuntimeVars) []byte { +func NewVm(state *State, vars RuntimeVars) *Vm { + return &Vm{vars: vars, state: state} +} + +func (vm *Vm) RunClosure(closure *Closure) []byte { // If the amount of gas supplied is less equal to 0 if closure.GetGas().Cmp(big.NewInt(0)) <= 0 { // TODO Do something @@ -71,17 +77,28 @@ func (vm *Vm) RunClosure(closure *Closure, state *State, vars RuntimeVars) []byt } switch op { - case oSTOP: + case oSTOP: // Stop the closure return closure.Return(nil) - case oPUSH: + case oPUSH: // Push PC+1 on to the stack pc++ val := closure.GetMem(pc).BigInt() stack.Push(val) - case oMSTORE: + case oMSTORE: // Store the value at stack top-1 in to memory at location stack top // Pop value of the stack - val := stack.Pop() - // Set the bytes to the memory field - mem = append(mem, ethutil.BigToBytes(val, 256)...) + val, mStart := stack.Popn() + // Ensure that memory is large enough to hold the data + // If it isn't resize the memory slice so that it may hold the value + bytesLen := big.NewInt(32) + totSize := new(big.Int).Add(mStart, bytesLen) + lenSize := big.NewInt(int64(len(mem))) + if totSize.Cmp(lenSize) > 0 { + // Calculate the diff between the sizes + diff := new(big.Int).Sub(totSize, lenSize) + // Create a new empty slice and append it + newSlice := make([]byte, diff.Int64()+1) + mem = append(mem, newSlice...) + } + copy(mem[mStart.Int64():mStart.Int64()+bytesLen.Int64()+1], ethutil.BigToBytes(val, 256)) case oCALL: // Pop return size and offset retSize, retOffset := stack.Popn() @@ -93,20 +110,25 @@ func (vm *Vm) RunClosure(closure *Closure, state *State, vars RuntimeVars) []byt gas, value := stack.Popn() // Closure addr addr := stack.Pop() - - contract := state.GetContract(addr.Bytes()) - closure := NewClosure(closure, contract, state, gas, value) - ret := vm.RunClosure(closure, state, vars) + // Fetch the contract which will serve as the closure body + contract := vm.state.GetContract(addr.Bytes()) + // Create a new callable closure + closure := NewClosure(closure, contract, vm.state, gas, value) + // Executer the closure and get the return value (if any) + ret := closure.Call(vm, nil) // Ensure that memory is large enough to hold the returned data + // If it isn't resize the memory slice so that it may hold the value totSize := new(big.Int).Add(retOffset, retSize) lenSize := big.NewInt(int64(len(mem))) - // Resize the current memory slice so that the return value may fit if totSize.Cmp(lenSize) > 0 { + // Calculate the diff between the sizes diff := new(big.Int).Sub(totSize, lenSize) + // Create a new empty slice and append it newSlice := make([]byte, diff.Int64()+1) mem = append(mem, newSlice...) } + // Copy over the returned values to the memory given the offset and size copy(mem[retOffset.Int64():retOffset.Int64()+retSize.Int64()+1], ret) case oRETURN: size, offset := stack.Popn() |