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 Origin() common.Address BlockNumber() *big.Int GetHash(n uint64) common.Hash Coinbase() common.Address Time() uint64 Difficulty() *big.Int GasLimit() *big.Int Transfer(from, to Account, amount *big.Int) error AddLog(*state.Log) AddStructLog(StructLog) StructLogs() []StructLog VmType() Type 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) } // StructLog is emited to the Environment each cycle and lists information about the curent internal state // prior to the execution of the statement. type StructLog struct { Pc uint64 Op OpCode Gas *big.Int GasCost *big.Int Memory []byte Stack []*big.Int Storage map[common.Hash][]byte Err error } type Account interface { SubBalance(amount *big.Int) AddBalance(amount *big.Int) 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 }