1 files changed, 93 insertions, 0 deletions
diff --git a/vm/execution.go b/vm/execution.go
new file mode 100644
index 000000000..8da0469de
--- /dev/null
+++ b/vm/execution.go
@@ -0,0 +1,93 @@
+package vm
+
+import (
+	"fmt"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/ethstate"
+	"github.com/ethereum/go-ethereum/ethutil"
+)
+
+type Execution struct {
+	vm                VirtualMachine
+	address, input    []byte
+	Gas, price, value *big.Int
+	object            *ethstate.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()
+
+	snapshot := env.State().Copy()
+	defer func() {
+		if IsDepthErr(err) || IsOOGErr(err) {
+			env.State().Set(snapshot)
+		}
+	}()
+
+	msg := env.State().Manifest().AddMessage(&ethstate.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 ClosureRef) (ret []byte, err error) {
+	return self.exec(self.input, nil, caller)
+}