path: root/core/execution.go

package core

import (
    "fmt"
    "math/big"

    "github.com/ethereum/go-ethereum/ethutil"
    "github.com/ethereum/go-ethereum/state"
    "github.com/ethereum/go-ethereum/vm"
)

type Execution struct {
    vm                vm.VirtualMachine
    address, input    []byte
    Gas, price, value *big.Int
    object            *state.StateObject
    SkipTransfer      bool
}

func NewExecution(vm 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) Call(codeAddr []byte, caller vm.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, contextAddr []byte, caller vm.ClosureRef) (ret []byte, err error) {
    env := self.vm.Env()
    chainlogger.Debugf("pre state %x\n", env.State().Root())

    from, to := env.State().GetStateObject(caller.Address()), 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)
    }

    snapshot := env.State().Copy()
    defer func() {
        if vm.IsDepthErr(err) || vm.IsOOGErr(err) {
            env.State().Set(snapshot)
        }
        chainlogger.Debugf("post state %x\n", env.State().Root())
    }()

    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(contextAddr).Uint64()
        if p := vm.Precompiled[naddr]; p != nil {
            if self.Gas.Cmp(p.Gas(len(self.input))) >= 0 {
                ret = p.Call(self.input)
                self.vm.Printf("NATIVE_FUNC(%x) => %x", naddr, ret)
                self.vm.Endl()
            }
        } else {
            ret, err = self.vm.Run(to, caller, code, self.value, self.Gas, self.price, self.input)
        }
    }

    return
}

func (self *Execution) Create(caller vm.ClosureRef) (ret []byte, err error, account *state.StateObject) {
    ret, err = self.exec(self.input, nil, caller)
    account = self.vm.Env().State().GetStateObject(self.address)

    return
}