go-ethereum/p2p/protocols/accounting.go
2018-10-12 11:18:35 -05:00

77 lines
2.2 KiB
Go

// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package protocols
type PriceOracle interface {
Price(uint32, interface{}) (EntryDirection, uint64)
Accountable(interface{}) bool
}
type BalanceManager interface {
//Credit is crediting the peer, charging local node
Credit(peer *Peer, amount uint64) error
//Debit is crediting the local node, charging the remote peer
Debit(peer *Peer, amount uint64) error
}
type EntryDirection bool
const (
ChargeSender EntryDirection = true
ChargeReceiver EntryDirection = false
)
type AccountingHook struct {
BalanceManager
PriceOracle
}
func NewAccountingHook(mgr BalanceManager, po PriceOracle) *AccountingHook {
ah := &AccountingHook{
PriceOracle: po,
BalanceManager: mgr,
}
return ah
}
func (ah *AccountingHook) Send(peer *Peer, size uint32, msg interface{}) error {
var err error
if !ah.PriceOracle.Accountable(msg) {
return nil
}
direction, price := ah.PriceOracle.Price(size, msg)
if direction == ChargeSender {
err = ah.BalanceManager.Debit(peer, price)
} else {
err = ah.BalanceManager.Credit(peer, price)
}
return err
}
func (ah *AccountingHook) Receive(peer *Peer, size uint32, msg interface{}) error {
var err error
if !ah.PriceOracle.Accountable(msg) {
return nil
}
direction, price := ah.PriceOracle.Price(size, msg)
if direction == ChargeReceiver {
err = ah.BalanceManager.Debit(peer, price)
} else {
err = ah.BalanceManager.Credit(peer, price)
}
return err
}