plugeth/ethchain/closure.go
obscuren 7705b23f24 Removed caller from tx and added "callership" to account.
Transactions can no longer serve as callers. Accounts are now the
initial callee of closures. Transactions now serve as transport to call
closures.
2014-03-20 23:17:53 +01:00

77 lines
1.5 KiB
Go

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
}
// 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
}