// Copyright 2015 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum 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.
//
// go-ethereum 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 go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package miner
import (
"math/big"
"sync"
"time"
"github.com/ethereum/ethash"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
)
type RemoteAgent struct {
mu sync.Mutex
quit chan struct{}
workCh chan *Work
returnCh chan<- *Result
currentWork *Work
work map[common.Hash]*Work
}
func NewRemoteAgent() *RemoteAgent {
agent := &RemoteAgent{work: make(map[common.Hash]*Work)}
return agent
}
func (a *RemoteAgent) Work() chan<- *Work {
return a.workCh
}
func (a *RemoteAgent) SetReturnCh(returnCh chan<- *Result) {
a.returnCh = returnCh
}
func (a *RemoteAgent) Start() {
a.quit = make(chan struct{})
a.workCh = make(chan *Work, 1)
go a.maintainLoop()
}
func (a *RemoteAgent) Stop() {
close(a.quit)
close(a.workCh)
}
func (a *RemoteAgent) GetHashRate() int64 { return 0 }
func (a *RemoteAgent) GetWork() [3]string {
a.mu.Lock()
defer a.mu.Unlock()
var res [3]string
if a.currentWork != nil {
block := a.currentWork.Block
res[0] = block.HashNoNonce().Hex()
seedHash, _ := ethash.GetSeedHash(block.NumberU64())
res[1] = common.BytesToHash(seedHash).Hex()
// Calculate the "target" to be returned to the external miner
n := big.NewInt(1)
n.Lsh(n, 255)
n.Div(n, block.Difficulty())
n.Lsh(n, 1)
res[2] = common.BytesToHash(n.Bytes()).Hex()
a.work[block.HashNoNonce()] = a.currentWork
}
return res
}
// Returns true or false, but does not indicate if the PoW was correct
func (a *RemoteAgent) SubmitWork(nonce uint64, mixDigest, hash common.Hash) bool {
a.mu.Lock()
defer a.mu.Unlock()
// Make sure the work submitted is present
if a.work[hash] != nil {
block := a.work[hash].Block.WithMiningResult(nonce, mixDigest)
a.returnCh <- &Result{a.work[hash], block}
delete(a.work, hash)
return true
} else {
glog.V(logger.Info).Infof("Work was submitted for %x but no pending work found\n", hash)
}
return false
}
func (a *RemoteAgent) maintainLoop() {
ticker := time.Tick(5 * time.Second)
out:
for {
select {
case <-a.quit:
break out
case work := <-a.workCh:
a.mu.Lock()
a.currentWork = work
a.mu.Unlock()
case <-ticker:
// cleanup
a.mu.Lock()
for hash, work := range a.work {
if time.Since(work.createdAt) > 7*(12*time.Second) {
delete(a.work, hash)
}
}
a.mu.Unlock()
}
}
}
