1 files changed, 61 insertions, 22 deletions

diff --git a/core/vm/environment.go b/core/vm/environment.go
index 916081f51..606518fd4 100644
--- a/core/vm/environment.go
+++ b/core/vm/environment.go
@@ -17,39 +17,86 @@
 package vm
 
 import (
-	"errors"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/state"
 )
 
 // Environment is is required by the virtual machine to get information from
-// it's own isolated environment. For an example see `core.VMEnv`
-type Environment interface {
-	State() *state.StateDB
+// it's own isolated environment.
 
+// Environment is an EVM requirement and helper which allows access to outside
+// information such like states.
+type Environment interface {
+	// The state database
+	Db() Database
+	// Creates a restorable snapshot
+	MakeSnapshot() Database
+	// Set database to previous snapshot
+	SetSnapshot(Database)
+	// Address of the original invoker (first occurance of the VM invoker)
 	Origin() common.Address
+	// The block number this VM is invoken on
 	BlockNumber() *big.Int
+	// The n'th hash ago from this block number
 	GetHash(n uint64) common.Hash
+	// The handler's address
 	Coinbase() common.Address
+	// The current time (block time)
 	Time() *big.Int
+	// Difficulty set on the current block
 	Difficulty() *big.Int
+	// The gas limit of the block
 	GasLimit() *big.Int
-	CanTransfer(from Account, balance *big.Int) bool
+	// Determines whether it's possible to transact
+	CanTransfer(from common.Address, balance *big.Int) bool
+	// Transfer from to to with amount set
 	Transfer(from, to Account, amount *big.Int) error
-	AddLog(*state.Log)
+	// Adds a LOG to the state
+	AddLog(*Log)
+	// Adds a structured log to the env
 	AddStructLog(StructLog)
+	// Returns all coalesced structured logs
 	StructLogs() []StructLog
 
+	// Type of the VM
 	VmType() Type
 
+	// Current calling depth
 	Depth() int
 	SetDepth(i int)
 
-	Call(me ContextRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error)
-	CallCode(me ContextRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error)
-	Create(me ContextRef, data []byte, gas, price, value *big.Int) ([]byte, error, ContextRef)
+	// Call another contract
+	Call(me ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error)
+	// Take another's contract code and execute within our own context
+	CallCode(me ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error)
+	// Create a new contract
+	Create(me ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error)
+}
+
+// Database is a EVM database for full state querying
+type Database interface {
+	GetAccount(common.Address) Account
+	CreateAccount(common.Address) Account
+
+	AddBalance(common.Address, *big.Int)
+	GetBalance(common.Address) *big.Int
+
+	GetNonce(common.Address) uint64
+	SetNonce(common.Address, uint64)
+
+	GetCode(common.Address) []byte
+	SetCode(common.Address, []byte)
+
+	AddRefund(*big.Int)
+	GetRefund() *big.Int
+
+	GetState(common.Address, common.Hash) common.Hash
+	SetState(common.Address, common.Hash, common.Hash)
+
+	Delete(common.Address) bool
+	Exist(common.Address) bool
+	IsDeleted(common.Address) bool
 }
 
 // StructLog is emited to the Environment each cycle and lists information about the curent internal state
@@ -68,18 +115,10 @@ type StructLog struct {
 type Account interface {
 	SubBalance(amount *big.Int)
 	AddBalance(amount *big.Int)
+	SetBalance(*big.Int)
+	SetNonce(uint64)
 	Balance() *big.Int
 	Address() common.Address
-}
-
-// generic transfer method
-func Transfer(from, to 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
+	ReturnGas(*big.Int, *big.Int)
+	SetCode([]byte)
 }