go-ethereum/vm/execution.go
2014-11-30 21:02:59 +01:00

96 lines
2.5 KiB
Go

package vm
import (
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/ethutil"
"github.com/ethereum/go-ethereum/state"
)
type Execution struct {
vm VirtualMachine
address, input []byte
Gas, price, value *big.Int
object *state.StateObject
SkipTransfer bool
}
func NewExecution(vm VirtualMachine, address, input []byte, gas, gasPrice, value *big.Int) *Execution {
return &Execution{vm: vm, address: address, input: input, Gas: gas, price: gasPrice, value: value}
}
func (self *Execution) Addr() []byte {
return self.address
}
func (self *Execution) Exec(codeAddr []byte, caller ClosureRef) ([]byte, error) {
// Retrieve the executing code
code := self.vm.Env().State().GetCode(codeAddr)
return self.exec(code, codeAddr, caller)
}
func (self *Execution) exec(code, caddr []byte, caller ClosureRef) (ret []byte, err error) {
env := self.vm.Env()
vmlogger.Debugf("pre state %x\n", env.State().Root())
snapshot := env.State().Copy()
defer func() {
if IsDepthErr(err) || IsOOGErr(err) {
env.State().Set(snapshot)
}
vmlogger.Debugf("post state %x\n", env.State().Root())
}()
msg := env.State().Manifest().AddMessage(&state.Message{
To: self.address, From: caller.Address(),
Input: self.input,
Origin: env.Origin(),
Block: env.BlockHash(), Timestamp: env.Time(), Coinbase: env.Coinbase(), Number: env.BlockNumber(),
Value: self.value,
})
from, to := caller.Object(), env.State().GetOrNewStateObject(self.address)
// Skipping transfer is used on testing for the initial call
if !self.SkipTransfer {
err = env.Transfer(from, to, self.value)
}
if err != nil {
caller.ReturnGas(self.Gas, self.price)
err = fmt.Errorf("Insufficient funds to transfer value. Req %v, has %v", self.value, from.Balance)
} else {
self.object = to
// Pre-compiled contracts (address.go) 1, 2 & 3.
naddr := ethutil.BigD(caddr).Uint64()
if p := Precompiled[naddr]; p != nil {
if self.Gas.Cmp(p.Gas) >= 0 {
ret = p.Call(self.input)
self.vm.Printf("NATIVE_FUNC(%x) => %x", naddr, ret)
}
} else {
// Create a new callable closure
c := NewClosure(msg, caller, to, code, self.Gas, self.price)
c.exe = self
if self.vm.Depth() == MaxCallDepth {
c.UseGas(self.Gas)
return c.Return(nil), DepthError{}
}
// Executer the closure and get the return value (if any)
ret, _, err = c.Call(self.vm, self.input)
msg.Output = ret
}
}
return
}
func (self *Execution) Create(caller []byte) (ret []byte, err error) {
return self.exec(self.input, nil, caller)
}