dione/blockchain/pool/mempool.go
2021-06-02 22:45:55 +03:00

87 lines
1.7 KiB
Go

package pool
import (
"encoding/hex"
"errors"
"sort"
"time"
types2 "github.com/Secured-Finance/dione/blockchain/types"
"github.com/Secured-Finance/dione/consensus/policy"
"github.com/Secured-Finance/dione/cache"
)
const (
DefaultTxTTL = 10 * time.Minute
DefaultTxPrefix = "tx_"
)
var (
ErrTxNotFound = errors.New("tx isn't found in mempool")
)
type Mempool struct {
cache cache.Cache
}
func NewMempool() (*Mempool, error) {
mp := &Mempool{
cache: cache.NewInMemoryCache(), // here we need to use separate cache
}
return mp, nil
}
func (mp *Mempool) StoreTx(tx *types2.Transaction) error {
hashStr := hex.EncodeToString(tx.Hash)
err := mp.cache.StoreWithTTL(DefaultTxPrefix+hashStr, tx, DefaultTxTTL)
return err
}
func (mp *Mempool) GetTransactionsForNewBlock() []*types2.Transaction {
var txForBlock []*types2.Transaction
allTxs := mp.GetAllTransactions()
sort.Slice(allTxs, func(i, j int) bool {
return allTxs[i].Timestamp.Before(allTxs[j].Timestamp)
})
for i := 0; i < policy.BlockMaxTransactionCount; i++ {
if len(allTxs) == 0 {
break
}
tx := allTxs[0] // get oldest tx
allTxs = allTxs[1:] // pop tx
txForBlock = append(txForBlock, tx)
}
return txForBlock
}
func (mp *Mempool) GetAllTransactions() []*types2.Transaction {
var allTxs []*types2.Transaction
for _, v := range mp.cache.Items() {
tx := v.(types2.Transaction)
allTxs = append(allTxs, &tx)
}
return allTxs
}
func (mp *Mempool) GetTransaction(hash []byte) (*types2.Transaction, error) {
hashStr := hex.EncodeToString(hash)
var tx types2.Transaction
err := mp.cache.Get(DefaultTxPrefix+hashStr, &tx)
if err != nil {
if errors.Is(err, cache.ErrNotFound) {
return nil, ErrTxNotFound
} else {
return nil, err
}
}
return &tx, nil
}