package core import ( "bytes" "encoding/binary" "fmt" "io" "github.com/CityOfZion/neo-go/pkg/core/storage" "github.com/CityOfZion/neo-go/pkg/util" ) // UnspentCoins is mapping between transactions and their unspent // coin state. type UnspentCoins map[util.Uint256]*UnspentCoinState func (u UnspentCoins) getAndChange(s storage.Store, hash util.Uint256) (*UnspentCoinState, error) { if unspent, ok := u[hash]; ok { return unspent, nil } unspent := &UnspentCoinState{} key := storage.AppendPrefix(storage.STCoin, hash.BytesReverse()) if b, err := s.Get(key); err == nil { if err := unspent.DecodeBinary(bytes.NewReader(b)); err != nil { return nil, fmt.Errorf("failed to decode (UnspentCoinState): %s", err) } } else { unspent = &UnspentCoinState{ states: []CoinState{}, } } u[hash] = unspent return unspent, nil } // UnspentCoinState hold the state of a unspent coin. type UnspentCoinState struct { states []CoinState } // commit writes all unspent coin states to the given Batch. func (s UnspentCoins) commit(b storage.Batch) error { buf := new(bytes.Buffer) for hash, state := range s { if err := state.EncodeBinary(buf); err != nil { return err } key := storage.AppendPrefix(storage.STCoin, hash.BytesReverse()) b.Put(key, buf.Bytes()) buf.Reset() } return nil } // EncodeBinary encodes UnspentCoinState to the given io.Writer. func (s *UnspentCoinState) EncodeBinary(w io.Writer) error { if err := util.WriteVarUint(w, uint64(len(s.states))); err != nil { return err } for _, state := range s.states { if err := binary.Write(w, binary.LittleEndian, byte(state)); err != nil { return err } } return nil } // DecodBinary decodes UnspentCoinState from the given io.Reader. func (s *UnspentCoinState) DecodeBinary(r io.Reader) error { lenStates := util.ReadVarUint(r) s.states = make([]CoinState, lenStates) for i := 0; i < int(lenStates); i++ { var state uint8 if err := binary.Read(r, binary.LittleEndian, &state); err != nil { return err } s.states[i] = CoinState(state) } return nil }