cmd/geth, miner: Added HTTP push notifications for new work packages

cmd/geth/main.go

@@ -122,6 +122,7 @@ var (
 		utils.GpoBlocksFlag,
 		utils.GpoPercentileFlag,
 		utils.ExtraDataFlag,
+		utils.NotifyWorkFlag,
 		configFileFlag,
 	}
 

cmd/geth/usage.go

@@ -189,6 +189,7 @@ var AppHelpFlagGroups = []flagGroup{
 			utils.TargetGasLimitFlag,
 			utils.GasPriceFlag,
 			utils.ExtraDataFlag,
+			utils.NotifyWorkFlag,
 		},
 	},
 	{

cmd/utils/flags.go

@@ -341,6 +341,10 @@ var (
 		Name:  "extradata",
 		Usage: "Block extra data set by the miner (default = client version)",
 	}
+	NotifyWorkFlag = cli.StringFlag{
+		Name:  "notifywork",
+		Usage: "URLs to which work package notifications are pushed. URLS should be a comma-delimited list of HTTP URLs.",
+	}
 	// Account settings
 	UnlockedAccountFlag = cli.StringFlag{
 		Name:  "unlock",
@@ -1100,6 +1104,9 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 	if ctx.GlobalIsSet(ExtraDataFlag.Name) {
 		cfg.ExtraData = []byte(ctx.GlobalString(ExtraDataFlag.Name))
 	}
+	if ctx.GlobalIsSet(NotifyWorkFlag.Name) {
+		cfg.NotifyWork = ctx.GlobalString(NotifyWorkFlag.Name)
+	}
 	if ctx.GlobalIsSet(GasPriceFlag.Name) {
 		cfg.GasPrice = GlobalBig(ctx, GasPriceFlag.Name)
 	}

eth/backend.go

@@ -169,6 +169,11 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 	eth.miner = miner.New(eth, eth.chainConfig, eth.EventMux(), eth.engine)
 	eth.miner.SetExtra(makeExtraData(config.ExtraData))
 
+	// Set up mining work push notifications if requested
+	if len(config.NotifyWork) > 0 {
+		eth.miner.Register(miner.NewNotificationAgent(eth.blockchain, eth.engine, config.NotifyWork))
+	}
+
 	eth.APIBackend = &EthAPIBackend{eth, nil}
 	gpoParams := config.GPO
 	if gpoParams.Default == nil {

eth/config.go

@@ -98,6 +98,7 @@ type Config struct {
 	Etherbase    common.Address `toml:",omitempty"`
 	MinerThreads int            `toml:",omitempty"`
 	ExtraData    []byte         `toml:",omitempty"`
+	NotifyWork   string         `toml:",omitempty"`
 	GasPrice     *big.Int
 
 	// Ethash options

miner/notification_agent.go

@@ -0,0 +1,123 @@
+// Copyright 2015 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 miner
+
+import (
+	"sync"
+
+	"bytes"
+	"encoding/json"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
+	"github.com/ethereum/go-ethereum/log"
+	"math/big"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// The notification agent pushes new work packages to a preset list of HTTP endpoints
+type NotificationAgent struct {
+	wg       sync.WaitGroup
+	workCh   chan *Work
+	stop     chan struct{}
+	returnCh chan<- *Result
+	targets  []string
+	client   *http.Client
+
+	chain  consensus.ChainReader
+	engine consensus.Engine
+}
+
+func NewNotificationAgent(chain consensus.ChainReader, engine consensus.Engine, targets string) *NotificationAgent {
+	miner := &NotificationAgent{
+		chain:   chain,
+		engine:  engine,
+		stop:    make(chan struct{}, 1),
+		workCh:  make(chan *Work, 1),
+		targets: strings.Split(targets, ","),
+		client:  &http.Client{Timeout: time.Second * 10},
+	}
+	return miner
+}
+
+func (self *NotificationAgent) Work() chan<- *Work            { return self.workCh }
+func (self *NotificationAgent) SetReturnCh(ch chan<- *Result) { self.returnCh = ch }
+
+func (self *NotificationAgent) Stop() {
+	self.stop <- struct{}{}
+done:
+	// Empty work channel
+	for {
+		select {
+		case <-self.workCh:
+		default:
+			break done
+		}
+	}
+}
+
+func (self *NotificationAgent) Start() {
+	go self.update()
+}
+
+func (self *NotificationAgent) update() {
+out:
+	for {
+		select {
+		case work := <-self.workCh:
+			var res [3]string
+
+			block := work.Block
+
+			res[0] = block.HashNoNonce().Hex()
+			seedHash := ethash.SeedHash(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()
+
+			resJson, err := json.Marshal(res)
+			if err != nil {
+				log.Error("Unable to marshal work package into JSON string")
+				continue
+			}
+
+			self.wg.Add(len(self.targets))
+			for _, target := range self.targets {
+				func(t string) {
+					_, err := self.client.Post(t, "application/json", bytes.NewBuffer(resJson))
+					if err != nil {
+						log.Error("Error invoking work notification handler", "handler", t, "err", err)
+					}
+					self.wg.Done()
+				}(target)
+			}
+			self.wg.Wait()
+		case <-self.stop:
+			break out
+		}
+	}
+}
+
+func (self *NotificationAgent) GetHashRate() int64 {
+	return 0
+}