neo-go/pkg/core/dao/cacheddao.go

126 lines
3.5 KiB
Go

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,
}
}