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`.

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)
 }

core/block_processor.go

@@ -25,6 +25,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
@@ -163,7 +164,7 @@ func (self *BlockProcessor) ApplyTransactions(gp GasPool, statedb *state.StateDB
 	return receipts, err
 }
 
-func (sm *BlockProcessor) RetryProcess(block *types.Block) (logs state.Logs, err error) {
+func (sm *BlockProcessor) RetryProcess(block *types.Block) (logs vm.Logs, err error) {
 	// Processing a blocks may never happen simultaneously
 	sm.mutex.Lock()
 	defer sm.mutex.Unlock()
@@ -188,7 +189,7 @@ func (sm *BlockProcessor) RetryProcess(block *types.Block) (logs state.Logs, err
 // Process block will attempt to process the given block's transactions and applies them
 // on top of the block's parent state (given it exists) and will return wether it was
 // successful or not.
-func (sm *BlockProcessor) Process(block *types.Block) (logs state.Logs, receipts types.Receipts, err error) {
+func (sm *BlockProcessor) Process(block *types.Block) (logs vm.Logs, receipts types.Receipts, err error) {
 	// Processing a blocks may never happen simultaneously
 	sm.mutex.Lock()
 	defer sm.mutex.Unlock()
@@ -204,7 +205,7 @@ func (sm *BlockProcessor) Process(block *types.Block) (logs state.Logs, receipts
 	return sm.processWithParent(block, parent)
 }
 
-func (sm *BlockProcessor) processWithParent(block, parent *types.Block) (logs state.Logs, receipts types.Receipts, err error) {
+func (sm *BlockProcessor) processWithParent(block, parent *types.Block) (logs vm.Logs, receipts types.Receipts, err error) {
 	// Create a new state based on the parent's root (e.g., create copy)
 	state := state.New(parent.Root(), sm.chainDb)
 	header := block.Header()
@@ -356,7 +357,7 @@ func (sm *BlockProcessor) GetBlockReceipts(bhash common.Hash) types.Receipts {
 // GetLogs returns the logs of the given block. This method is using a two step approach
 // where it tries to get it from the (updated) method which gets them from the receipts or
 // the depricated way by re-processing the block.
-func (sm *BlockProcessor) GetLogs(block *types.Block) (logs state.Logs, err error) {
+func (sm *BlockProcessor) GetLogs(block *types.Block) (logs vm.Logs, err error) {
 	receipts := GetBlockReceipts(sm.chainDb, block.Hash())
 	// coalesce logs
 	for _, receipt := range receipts {

core/block_processor_test.go

@@ -24,6 +24,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/pow/ezp"
@@ -69,7 +70,7 @@ func TestPutReceipt(t *testing.T) {
 	hash[0] = 2
 
 	receipt := new(types.Receipt)
-	receipt.SetLogs(state.Logs{&state.Log{
+	receipt.SetLogs(vm.Logs{&vm.Log{
 		Address:   addr,
 		Topics:    []common.Hash{hash},
 		Data:      []byte("hi"),

core/chain_manager_test.go

@@ -28,8 +28,8 @@ import (
 
 	"github.com/ethereum/ethash"
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
@@ -361,7 +361,7 @@ func TestChainMultipleInsertions(t *testing.T) {
 
 type bproc struct{}
 
-func (bproc) Process(*types.Block) (state.Logs, types.Receipts, error) { return nil, nil, nil }
+func (bproc) Process(*types.Block) (vm.Logs, types.Receipts, error) { return nil, nil, nil }
 
 func makeChainWithDiff(genesis *types.Block, d []int, seed byte) []*types.Block {
 	var chain []*types.Block

core/events.go

@@ -20,8 +20,8 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
 )
 
 // TxPreEvent is posted when a transaction enters the transaction pool.
@@ -42,23 +42,23 @@ type RemovedTransactionEvent struct{ Txs types.Transactions }
 // ChainSplit is posted when a new head is detected
 type ChainSplitEvent struct {
 	Block *types.Block
-	Logs  state.Logs
+	Logs  vm.Logs
 }
 
 type ChainEvent struct {
 	Block *types.Block
 	Hash  common.Hash
-	Logs  state.Logs
+	Logs  vm.Logs
 }
 
 type ChainSideEvent struct {
 	Block *types.Block
-	Logs  state.Logs
+	Logs  vm.Logs
 }
 
 type PendingBlockEvent struct {
 	Block *types.Block
-	Logs  state.Logs
+	Logs  vm.Logs
 }
 
 type ChainUncleEvent struct {

core/execution.go

@@ -17,108 +17,104 @@
 package core
 
 import (
+	"errors"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
 )
 
-// Execution is the execution environment for the given call or create action.
-type Execution struct {
-	env     vm.Environment
-	address *common.Address
-	input   []byte
-	evm     vm.VirtualMachine
-
-	Gas, price, value *big.Int
+// Call executes within the given contract
+func Call(env vm.Environment, caller vm.ContractRef, addr common.Address, input []byte, gas, gasPrice, value *big.Int) (ret []byte, err error) {
+	ret, _, err = exec(env, caller, &addr, &addr, input, env.Db().GetCode(addr), gas, gasPrice, value)
+	return ret, err
 }
 
-// NewExecution returns a new execution environment that handles all calling
-// and creation logic defined by the YP.
-func NewExecution(env vm.Environment, address *common.Address, input []byte, gas, gasPrice, value *big.Int) *Execution {
-	exe := &Execution{env: env, address: address, input: input, Gas: gas, price: gasPrice, value: value}
-	exe.evm = vm.NewVm(env)
-	return exe
+// CallCode executes the given address' code as the given contract address
+func CallCode(env vm.Environment, caller vm.ContractRef, addr common.Address, input []byte, gas, gasPrice, value *big.Int) (ret []byte, err error) {
+	prev := caller.Address()
+	ret, _, err = exec(env, caller, &prev, &addr, input, env.Db().GetCode(addr), gas, gasPrice, value)
+	return ret, err
 }
 
-// Call executes within the given context
-func (self *Execution) Call(codeAddr common.Address, caller vm.ContextRef) ([]byte, error) {
-	// Retrieve the executing code
-	code := self.env.State().GetCode(codeAddr)
-
-	return self.exec(&codeAddr, code, caller)
-}
-
-// Create creates a new contract and runs the initialisation procedure of the
-// contract. This returns the returned code for the contract and is stored
-// elsewhere.
-func (self *Execution) Create(caller vm.ContextRef) (ret []byte, err error, account *state.StateObject) {
-	// Input must be nil for create
-	code := self.input
-	self.input = nil
-	ret, err = self.exec(nil, code, caller)
+// Create creates a new contract with the given code
+func Create(env vm.Environment, caller vm.ContractRef, code []byte, gas, gasPrice, value *big.Int) (ret []byte, address common.Address, err error) {
+	ret, address, err = exec(env, caller, nil, nil, nil, code, gas, gasPrice, value)
 	// Here we get an error if we run into maximum stack depth,
 	// See: https://github.com/ethereum/yellowpaper/pull/131
 	// and YP definitions for CREATE instruction
 	if err != nil {
-		return nil, err, nil
+		return nil, address, err
 	}
-	account = self.env.State().GetStateObject(*self.address)
-	return
+	return ret, address, err
 }
 
-// exec executes the given code and executes within the contextAddr context.
-func (self *Execution) exec(contextAddr *common.Address, code []byte, caller vm.ContextRef) (ret []byte, err error) {
-	env := self.env
-	evm := self.evm
+func exec(env vm.Environment, caller vm.ContractRef, address, codeAddr *common.Address, input, code []byte, gas, gasPrice, value *big.Int) (ret []byte, addr common.Address, err error) {
+	evm := vm.NewVm(env)
+
 	// Depth check execution. Fail if we're trying to execute above the
 	// limit.
 	if env.Depth() > int(params.CallCreateDepth.Int64()) {
-		caller.ReturnGas(self.Gas, self.price)
+		caller.ReturnGas(gas, gasPrice)
 
-		return nil, vm.DepthError
+		return nil, common.Address{}, vm.DepthError
 	}
 
-	if !env.CanTransfer(env.State().GetStateObject(caller.Address()), self.value) {
-		caller.ReturnGas(self.Gas, self.price)
+	if !env.CanTransfer(caller.Address(), value) {
+		caller.ReturnGas(gas, gasPrice)
 
-		return nil, ValueTransferErr("insufficient funds to transfer value. Req %v, has %v", self.value, env.State().GetBalance(caller.Address()))
+		return nil, common.Address{}, ValueTransferErr("insufficient funds to transfer value. Req %v, has %v", value, env.Db().GetBalance(caller.Address()))
 	}
 
 	var createAccount bool
-	if self.address == nil {
+	if address == nil {
 		// Generate a new address
-		nonce := env.State().GetNonce(caller.Address())
-		env.State().SetNonce(caller.Address(), nonce+1)
+		nonce := env.Db().GetNonce(caller.Address())
+		env.Db().SetNonce(caller.Address(), nonce+1)
 
-		addr := crypto.CreateAddress(caller.Address(), nonce)
+		addr = crypto.CreateAddress(caller.Address(), nonce)
 
-		self.address = &addr
+		address = &addr
 		createAccount = true
 	}
-	snapshot := env.State().Copy()
+	snapshot := env.MakeSnapshot()
 
 	var (
-		from = env.State().GetStateObject(caller.Address())
-		to   *state.StateObject
+		from = env.Db().GetAccount(caller.Address())
+		to   vm.Account
 	)
 	if createAccount {
-		to = env.State().CreateAccount(*self.address)
+		to = env.Db().CreateAccount(*address)
 	} else {
-		to = env.State().GetOrNewStateObject(*self.address)
+		if !env.Db().Exist(*address) {
+			to = env.Db().CreateAccount(*address)
+		} else {
+			to = env.Db().GetAccount(*address)
+		}
 	}
-	vm.Transfer(from, to, self.value)
+	env.Transfer(from, to, value)
 
-	context := vm.NewContext(caller, to, self.value, self.Gas, self.price)
-	context.SetCallCode(contextAddr, code)
+	contract := vm.NewContract(caller, to, value, gas, gasPrice)
+	contract.SetCallCode(codeAddr, code)
 
-	ret, err = evm.Run(context, self.input)
+	ret, err = evm.Run(contract, input)
 	if err != nil {
-		env.State().Set(snapshot)
+		env.SetSnapshot(snapshot) //env.Db().Set(snapshot)
 	}
 
-	return
+	return ret, addr, err
+}
+
+// generic transfer method
+func Transfer(from, to vm.Account, amount *big.Int) error {
+	if from.Balance().Cmp(amount) < 0 {
+		return errors.New("Insufficient balance in account")
+	}
+
+	from.SubBalance(amount)
+	to.AddBalance(amount)
+
+	return nil
 }