cmd/evm, core/vm, test: refactored VM and core

* Moved `vm.Transfer` to `core` package and changed execution to call
`env.Transfer` instead of `core.Transfer` directly.
* core/vm: byte code VM moved to jump table instead of switch
* Moved `vm.Transfer` to `core` package and changed execution to call
  `env.Transfer` instead of `core.Transfer` directly.
* Byte code VM now shares the same code as the JITVM
* Renamed Context to Contract
* Changed initialiser of state transition & unexported methods
* Removed the Execution object and refactor `Call`, `CallCode` &
  `Create` in to their own functions instead of being methods.
* Removed the hard dep on the state for the VM. The VM now
  depends on a Database interface returned by the environment. In the
  process the core now depends less on the statedb by usage of the env
* Moved `Log` from package `core/state` to package `core/vm`.

1 files changed, 31 insertions, 33 deletions

diff --git a/cmd/evm/main.go b/cmd/evm/main.go
index 243dd6266..bf24da982 100644
--- a/cmd/evm/main.go
+++ b/cmd/evm/main.go
@@ -80,12 +80,17 @@ var (
 		Name:  "sysstat",
 		Usage: "display system stats",
 	}
+	VerbosityFlag = cli.IntFlag{
+		Name:  "verbosity",
+		Usage: "sets the verbosity level",
+	}
 )
 
 func init() {
 	app = utils.NewApp("0.2", "the evm command line interface")
 	app.Flags = []cli.Flag{
 		DebugFlag,
+		VerbosityFlag,
 		ForceJitFlag,
 		DisableJitFlag,
 		SysStatFlag,
@@ -105,6 +110,7 @@ func run(ctx *cli.Context) {
 	vm.EnableJit = !ctx.GlobalBool(DisableJitFlag.Name)
 
 	glog.SetToStderr(true)
+	glog.SetV(ctx.GlobalInt(VerbosityFlag.Name))
 
 	db, _ := ethdb.NewMemDatabase()
 	statedb := state.New(common.Hash{}, db)
@@ -179,18 +185,20 @@ func NewEnv(state *state.StateDB, transactor common.Address, value *big.Int) *VM
 	}
 }
 
-func (self *VMEnv) State() *state.StateDB    { return self.state }
-func (self *VMEnv) Origin() common.Address   { return *self.transactor }
-func (self *VMEnv) BlockNumber() *big.Int    { return common.Big0 }
-func (self *VMEnv) Coinbase() common.Address { return *self.transactor }
-func (self *VMEnv) Time() *big.Int           { return self.time }
-func (self *VMEnv) Difficulty() *big.Int     { return common.Big1 }
-func (self *VMEnv) BlockHash() []byte        { return make([]byte, 32) }
-func (self *VMEnv) Value() *big.Int          { return self.value }
-func (self *VMEnv) GasLimit() *big.Int       { return big.NewInt(1000000000) }
-func (self *VMEnv) VmType() vm.Type          { return vm.StdVmTy }
-func (self *VMEnv) Depth() int               { return 0 }
-func (self *VMEnv) SetDepth(i int)           { self.depth = i }
+func (self *VMEnv) Db() vm.Database            { return self.state }
+func (self *VMEnv) MakeSnapshot() vm.Database  { return self.state.Copy() }
+func (self *VMEnv) SetSnapshot(db vm.Database) { self.state.Set(db.(*state.StateDB)) }
+func (self *VMEnv) Origin() common.Address     { return *self.transactor }
+func (self *VMEnv) BlockNumber() *big.Int      { return common.Big0 }
+func (self *VMEnv) Coinbase() common.Address   { return *self.transactor }
+func (self *VMEnv) Time() *big.Int             { return self.time }
+func (self *VMEnv) Difficulty() *big.Int       { return common.Big1 }
+func (self *VMEnv) BlockHash() []byte          { return make([]byte, 32) }
+func (self *VMEnv) Value() *big.Int            { return self.value }
+func (self *VMEnv) GasLimit() *big.Int         { return big.NewInt(1000000000) }
+func (self *VMEnv) VmType() vm.Type            { return vm.StdVmTy }
+func (self *VMEnv) Depth() int                 { return 0 }
+func (self *VMEnv) SetDepth(i int)             { self.depth = i }
 func (self *VMEnv) GetHash(n uint64) common.Hash {
 	if self.block.Number().Cmp(big.NewInt(int64(n))) == 0 {
 		return self.block.Hash()
@@ -203,34 +211,24 @@ func (self *VMEnv) AddStructLog(log vm.StructLog) {
 func (self *VMEnv) StructLogs() []vm.StructLog {
 	return self.logs
 }
-func (self *VMEnv) AddLog(log *state.Log) {
+func (self *VMEnv) AddLog(log *vm.Log) {
 	self.state.AddLog(log)
 }
-func (self *VMEnv) CanTransfer(from vm.Account, balance *big.Int) bool {
-	return from.Balance().Cmp(balance) >= 0
+func (self *VMEnv) CanTransfer(from common.Address, balance *big.Int) bool {
+	return self.state.GetBalance(from).Cmp(balance) >= 0
 }
 func (self *VMEnv) Transfer(from, to vm.Account, amount *big.Int) error {
-	return vm.Transfer(from, to, amount)
-}
-
-func (self *VMEnv) vm(addr *common.Address, data []byte, gas, price, value *big.Int) *core.Execution {
-	return core.NewExecution(self, addr, data, gas, price, value)
+	return core.Transfer(from, to, amount)
 }
 
-func (self *VMEnv) Call(caller vm.ContextRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
-	exe := self.vm(&addr, data, gas, price, value)
-	ret, err := exe.Call(addr, caller)
-	self.Gas = exe.Gas
-
-	return ret, err
+func (self *VMEnv) Call(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
+	self.Gas = gas
+	return core.Call(self, caller, addr, data, gas, price, value)
 }
-func (self *VMEnv) CallCode(caller vm.ContextRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
-	a := caller.Address()
-	exe := self.vm(&a, data, gas, price, value)
-	return exe.Call(addr, caller)
+func (self *VMEnv) CallCode(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
+	return core.CallCode(self, caller, addr, data, gas, price, value)
 }
 
-func (self *VMEnv) Create(caller vm.ContextRef, data []byte, gas, price, value *big.Int) ([]byte, error, vm.ContextRef) {
-	exe := self.vm(nil, data, gas, price, value)
-	return exe.Create(caller)
+func (self *VMEnv) Create(caller vm.ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error) {
+	return core.Create(self, caller, data, gas, price, value)
 }