package dao import ( "errors" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/io" "github.com/nspcc-dev/neo-go/pkg/util" ) // Cached is a data access object that mimics DAO, but has a write cache // for accounts and NEP17 transfer data. These are the most frequently used // objects in the storeBlock(). type Cached struct { DAO balances map[util.Uint160]*state.NEP17Balances transfers map[util.Uint160]map[uint32]*state.NEP17TransferLog dropNEP17Cache bool } // NewCached returns new Cached wrapping around given backing store. func NewCached(d DAO) *Cached { balances := make(map[util.Uint160]*state.NEP17Balances) transfers := make(map[util.Uint160]map[uint32]*state.NEP17TransferLog) return &Cached{d.GetWrapped(), balances, transfers, false} } // GetNEP17Balances retrieves NEP17Balances for the acc. func (cd *Cached) GetNEP17Balances(acc util.Uint160) (*state.NEP17Balances, error) { if bs := cd.balances[acc]; bs != nil { return bs, nil } return cd.DAO.GetNEP17Balances(acc) } // PutNEP17Balances saves NEP17Balances for the acc. func (cd *Cached) PutNEP17Balances(acc util.Uint160, bs *state.NEP17Balances) error { cd.balances[acc] = bs return nil } // GetNEP17TransferLog retrieves NEP17TransferLog for the acc. func (cd *Cached) GetNEP17TransferLog(acc util.Uint160, index uint32) (*state.NEP17TransferLog, error) { ts := cd.transfers[acc] if ts != nil && ts[index] != nil { return ts[index], nil } return cd.DAO.GetNEP17TransferLog(acc, index) } // PutNEP17TransferLog saves NEP17TransferLog for the acc. func (cd *Cached) PutNEP17TransferLog(acc util.Uint160, index uint32, bs *state.NEP17TransferLog) error { ts := cd.transfers[acc] if ts == nil { ts = make(map[uint32]*state.NEP17TransferLog, 2) cd.transfers[acc] = ts } ts[index] = bs return nil } // AppendNEP17Transfer appends new transfer to a transfer event log. func (cd *Cached) AppendNEP17Transfer(acc util.Uint160, index uint32, tr *state.NEP17Transfer) (bool, error) { lg, err := cd.GetNEP17TransferLog(acc, index) if err != nil { return false, err } if err := lg.Append(tr); err != nil { return false, err } return lg.Size() >= state.NEP17TransferBatchSize, cd.PutNEP17TransferLog(acc, index, lg) } // Persist flushes all the changes made into the (supposedly) persistent // underlying store. func (cd *Cached) Persist() (int, error) { lowerCache, ok := cd.DAO.(*Cached) // If the lower DAO is Cached, we only need to flush the MemCached DB. // This actually breaks DAO interface incapsulation, but for our current // usage scenario it should be good enough if cd doesn't modify object // caches (accounts/transfer data) in any way. if ok { if cd.dropNEP17Cache { lowerCache.balances = make(map[util.Uint160]*state.NEP17Balances) } var simpleCache *Simple for simpleCache == nil { simpleCache, ok = lowerCache.DAO.(*Simple) if !ok { lowerCache, ok = cd.DAO.(*Cached) if !ok { return 0, errors.New("unsupported lower DAO") } } } return simpleCache.Persist() } buf := io.NewBufBinWriter() for acc, bs := range cd.balances { err := cd.DAO.putNEP17Balances(acc, bs, buf) if err != nil { return 0, err } buf.Reset() } for acc, ts := range cd.transfers { for ind, lg := range ts { err := cd.DAO.PutNEP17TransferLog(acc, ind, lg) if err != nil { return 0, err } } } return cd.DAO.Persist() } // GetWrapped implements DAO interface. func (cd *Cached) GetWrapped() DAO { return &Cached{cd.DAO.GetWrapped(), cd.balances, cd.transfers, false, } }