package ethchain import ( "github.com/ethereum/eth-go/ethutil" "math/big" ) // States within the ethereum protocol are used to store anything // within the merkle trie. States take care of caching and storing // nested states. It's the general query interface to retrieve: // * Contracts // * Accounts type State struct { // The trie for this structure trie *ethutil.Trie // Nested states states map[string]*State manifest *Manifest } // Create a new state from a given trie func NewState(trie *ethutil.Trie) *State { return &State{trie: trie, states: make(map[string]*State), manifest: NewManifest()} } // Resets the trie and all siblings func (s *State) Reset() { s.trie.Undo() // Reset all nested states for _, state := range s.states { state.Reset() } } // Syncs the trie and all siblings func (s *State) Sync() { // Sync all nested states for _, state := range s.states { state.Sync() } s.trie.Sync() } // Purges the current trie. func (s *State) Purge() int { return s.trie.NewIterator().Purge() } func (s *State) GetStateObject(addr []byte) *StateObject { data := s.trie.Get(string(addr)) if data == "" { return nil } stateObject := NewStateObjectFromBytes(addr, []byte(data)) // Check if there's a cached state for this contract cachedStateObject := s.states[string(addr)] if cachedStateObject != nil { //fmt.Printf("get cached #%d %x addr: %x\n", cachedStateObject.trie.Cache().Len(), cachedStateObject.Root(), addr[0:4]) stateObject.state = cachedStateObject } return stateObject } // Updates any given state object func (s *State) UpdateStateObject(object *StateObject) { addr := object.Address() if object.state != nil && s.states[string(addr)] == nil { s.states[string(addr)] = object.state //fmt.Printf("update cached #%d %x addr: %x\n", object.state.trie.Cache().Len(), object.state.Root(), addr[0:4]) } ethutil.Config.Db.Put(ethutil.Sha3Bin(object.Script()), object.Script()) s.trie.Update(string(addr), string(object.RlpEncode())) s.manifest.AddObjectChange(object) } func (s *State) GetAccount(addr []byte) (account *StateObject) { data := s.trie.Get(string(addr)) if data == "" { account = NewAccount(addr, big.NewInt(0)) } else { account = NewStateObjectFromBytes(addr, []byte(data)) } return } func (s *State) Cmp(other *State) bool { return s.trie.Cmp(other.trie) } func (s *State) Copy() *State { state := NewState(s.trie.Copy()) for k, subState := range s.states { state.states[k] = subState.Copy() } return state } func (s *State) Snapshot() *State { return s.Copy() } func (s *State) Revert(snapshot *State) { s.trie = snapshot.trie s.states = snapshot.states } func (s *State) Put(key, object []byte) { s.trie.Update(string(key), string(object)) } func (s *State) Root() interface{} { return s.trie.Root } // Object manifest // // The object manifest is used to keep changes to the state so we can keep track of the changes // that occurred during a state transitioning phase. type Manifest struct { // XXX These will be handy in the future. Not important for now. objectAddresses map[string]bool storageAddresses map[string]map[string]bool objectChanges map[string]*StateObject storageChanges map[string]map[string]*big.Int } func NewManifest() *Manifest { m := &Manifest{objectAddresses: make(map[string]bool), storageAddresses: make(map[string]map[string]bool)} m.Reset() return m } func (m *Manifest) Reset() { m.objectChanges = make(map[string]*StateObject) m.storageChanges = make(map[string]map[string]*big.Int) } func (m *Manifest) AddObjectChange(stateObject *StateObject) { m.objectChanges[string(stateObject.Address())] = stateObject } func (m *Manifest) AddStorageChange(stateObject *StateObject, storageAddr []byte, storage *big.Int) { if m.storageChanges[string(stateObject.Address())] == nil { m.storageChanges[string(stateObject.Address())] = make(map[string]*big.Int) } m.storageChanges[string(stateObject.Address())][string(storageAddr)] = storage }