plugeth/ethchain/closure.go

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package ethchain
// TODO Re write VM to use values instead of big integers?
import (
"github.com/ethereum/eth-go/ethutil"
"math/big"
)
type Callee interface {
ReturnGas(*big.Int, *State)
}
type ClosureBody interface {
Callee
ethutil.RlpEncodable
GetMem(int64) *ethutil.Value
Address() []byte
}
// Basic inline closure object which implement the 'closure' interface
type Closure struct {
callee Callee
object ClosureBody
State *State
gas *big.Int
val *big.Int
Args []byte
}
// Create a new closure for the given data items
func NewClosure(callee Callee, object ClosureBody, state *State, gas, val *big.Int) *Closure {
return &Closure{callee, object, state, gas, val, nil}
}
// Retuns the x element in data slice
func (c *Closure) GetMem(x int64) *ethutil.Value {
m := c.object.GetMem(x)
if m == nil {
return ethutil.EmptyValue()
}
return m
}
func (c *Closure) Call(vm *Vm, args []byte) []byte {
c.Args = args
return vm.RunClosure(c)
}
func (c *Closure) Return(ret []byte) []byte {
// Return the remaining gas to the callee
// If no callee is present return it to
// the origin (i.e. contract or tx)
if c.callee != nil {
c.callee.ReturnGas(c.gas, c.State)
} else {
c.object.ReturnGas(c.gas, c.State)
// TODO incase it's a POST contract we gotta serialise the contract again.
// But it's not yet defined
}
return ret
}
// Implement the Callee interface
func (c *Closure) ReturnGas(gas *big.Int, state *State) {
// Return the gas to the closure
c.gas.Add(c.gas, gas)
}
func (c *Closure) GetGas() *big.Int {
return c.gas
}