all: finish integrating Go ethash, delete C++ vendor

20 files changed, 230 insertions, 800 deletions

diff --git a/cmd/geth/main.go b/cmd/geth/main.go
index bf5e81d45..cc6d3ac6a 100644
--- a/cmd/geth/main.go
+++ b/cmd/geth/main.go
@@ -95,6 +95,7 @@ func init() {
 		utils.EthashCachesInMemoryFlag,
 		utils.EthashCachesOnDiskFlag,
 		utils.EthashDatasetDirFlag,
+		utils.EthashDatasetsInMemoryFlag,
 		utils.EthashDatasetsOnDiskFlag,
 		utils.FastSyncFlag,
 		utils.LightModeFlag,
@@ -111,7 +112,6 @@ func init() {
 		utils.GasPriceFlag,
 		utils.MinerThreadsFlag,
 		utils.MiningEnabledFlag,
-		utils.AutoDAGFlag,
 		utils.TargetGasLimitFlag,
 		utils.NATFlag,
 		utils.NoDiscoverFlag,
diff --git a/cmd/geth/misccmd.go b/cmd/geth/misccmd.go
index 077f1ad11..073c36beb 100644
--- a/cmd/geth/misccmd.go
+++ b/cmd/geth/misccmd.go
@@ -25,10 +25,10 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/ethereum/ethash"
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/eth"
 	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/pow"
 	"gopkg.in/urfave/cli.v1"
 )
 
@@ -87,7 +87,7 @@ func makedag(ctx *cli.Context) error {
 				utils.Fatalf("Can't find dir")
 			}
 			fmt.Println("making DAG, this could take awhile...")
-			ethash.MakeDAG(blockNum, dir)
+			pow.MakeDataset(blockNum, dir)
 		}
 	default:
 		wrongArgs()
diff --git a/cmd/geth/usage.go b/cmd/geth/usage.go
index 34910daa5..74768f507 100644
--- a/cmd/geth/usage.go
+++ b/cmd/geth/usage.go
@@ -84,6 +84,7 @@ var AppHelpFlagGroups = []flagGroup{
 			utils.EthashCachesInMemoryFlag,
 			utils.EthashCachesOnDiskFlag,
 			utils.EthashDatasetDirFlag,
+			utils.EthashDatasetsInMemoryFlag,
 			utils.EthashDatasetsOnDiskFlag,
 		},
 	},
@@ -141,7 +142,6 @@ var AppHelpFlagGroups = []flagGroup{
 		Flags: []cli.Flag{
 			utils.MiningEnabledFlag,
 			utils.MinerThreadsFlag,
-			utils.AutoDAGFlag,
 			utils.EtherbaseFlag,
 			utils.TargetGasLimitFlag,
 			utils.GasPriceFlag,
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index b92be8464..38c90d801 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -132,9 +132,14 @@ var (
 		Name:  "ethash.dagdir",
 		Usage: "Directory to store the ethash mining DAGs (default = inside home folder)",
 	}
+	EthashDatasetsInMemoryFlag = cli.IntFlag{
+		Name:  "ethash.dagsinmem",
+		Usage: "Number of recent ethash mining DAGs to keep in memory (1+GB each)",
+		Value: 1,
+	}
 	EthashDatasetsOnDiskFlag = cli.IntFlag{
 		Name:  "ethash.dagsondisk",
-		Usage: "Number of ethash mining DAGs to keep on disk (1+GB each)",
+		Usage: "Number of recent ethash mining DAGs to keep on disk (1+GB each)",
 		Value: 2,
 	}
 	NetworkIdFlag = cli.IntFlag{
@@ -207,10 +212,6 @@ var (
 		Usage: "Target gas limit sets the artificial target gas floor for the blocks to mine",
 		Value: params.GenesisGasLimit.Uint64(),
 	}
-	AutoDAGFlag = cli.BoolFlag{
-		Name:  "autodag",
-		Usage: "Enable automatic DAG pregeneration",
-	}
 	EtherbaseFlag = cli.StringFlag{
 		Name:  "etherbase",
 		Usage: "Public address for block mining rewards (default = first account created)",
@@ -809,8 +810,8 @@ func RegisterEthService(ctx *cli.Context, stack *node.Node, extra []byte) {
 		EthashCachesInMem:       ctx.GlobalInt(EthashCachesInMemoryFlag.Name),
 		EthashCachesOnDisk:      ctx.GlobalInt(EthashCachesOnDiskFlag.Name),
 		EthashDatasetDir:        MakeEthashDatasetDir(ctx),
+		EthashDatasetsInMem:     ctx.GlobalInt(EthashDatasetsInMemoryFlag.Name),
 		EthashDatasetsOnDisk:    ctx.GlobalInt(EthashDatasetsOnDiskFlag.Name),
-		AutoDAG:                 ctx.GlobalBool(AutoDAGFlag.Name) || ctx.GlobalBool(MiningEnabledFlag.Name),
 		EnablePreimageRecording: ctx.GlobalBool(VMEnableDebugFlag.Name),
 	}
 
@@ -982,7 +983,7 @@ func MakeChain(ctx *cli.Context, stack *node.Node) (chain *core.BlockChain, chai
 
 	seal := pow.PoW(pow.FakePow{})
 	if !ctx.GlobalBool(FakePoWFlag.Name) {
-		seal = pow.NewFullEthash("", 1, 0, "", 0)
+		seal = pow.NewFullEthash("", 1, 0, "", 1, 0)
 	}
 	chain, err = core.NewBlockChain(chainDb, chainConfig, seal, new(event.TypeMux), vm.Config{EnablePreimageRecording: ctx.GlobalBool(VMEnableDebugFlag.Name)})
 	if err != nil {
diff --git a/eth/api.go b/eth/api.go
index 3aac34ee0..b17968ebb 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -29,7 +29,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/ethereum/ethash"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core"
@@ -40,7 +39,6 @@ import (
 	"github.com/ethereum/go-ethereum/miner"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
-	"github.com/ethereum/go-ethereum/rpc"
 	"golang.org/x/net/context"
 )
 
@@ -137,7 +135,6 @@ func NewPrivateMinerAPI(e *Ethereum) *PrivateMinerAPI {
 // Start the miner with the given number of threads. If threads is nil the number of
 // workers started is equal to the number of logical CPU's that are usable by this process.
 func (s *PrivateMinerAPI) Start(threads *int) (bool, error) {
-	s.e.StartAutoDAG()
 	var err error
 	if threads == nil {
 		err = s.e.StartMining(runtime.NumCPU())
@@ -173,25 +170,9 @@ func (s *PrivateMinerAPI) SetEtherbase(etherbase common.Address) bool {
 	return true
 }
 
-// StartAutoDAG starts auto DAG generation. This will prevent the DAG generating on epoch change
-// which will cause the node to stop mining during the generation process.
-func (s *PrivateMinerAPI) StartAutoDAG() bool {
-	s.e.StartAutoDAG()
-	return true
-}
-
-// StopAutoDAG stops auto DAG generation
-func (s *PrivateMinerAPI) StopAutoDAG() bool {
-	s.e.StopAutoDAG()
-	return true
-}
-
-// MakeDAG creates the new DAG for the given block number
-func (s *PrivateMinerAPI) MakeDAG(blockNr rpc.BlockNumber) (bool, error) {
-	if err := ethash.MakeDAG(uint64(blockNr.Int64()), ""); err != nil {
-		return false, err
-	}
-	return true, nil
+// GetHashrate returns the current hashrate of the miner.
+func (s *PrivateMinerAPI) GetHashrate() uint64 {
+	return uint64(s.e.miner.HashRate())
 }
 
 // PrivateAdminAPI is the collection of Etheruem full node-related APIs
diff --git a/eth/backend.go b/eth/backend.go
index d49251d75..ef951a6c2 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -21,14 +21,11 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
-	"os"
-	"path/filepath"
 	"regexp"
 	"strings"
 	"sync"
 	"time"
 
-	"github.com/ethereum/ethash"
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
@@ -78,7 +75,6 @@ type Config struct {
 	DatabaseHandles    int
 
 	DocRoot   string
-	AutoDAG   bool
 	PowFake   bool
 	PowTest   bool
 	PowShared bool
@@ -88,6 +84,7 @@ type Config struct {
 	EthashCachesInMem    int
 	EthashCachesOnDisk   int
 	EthashDatasetDir     string
+	EthashDatasetsInMem  int
 	EthashDatasetsOnDisk int
 
 	Etherbase    common.Address
@@ -138,8 +135,6 @@ type Ethereum struct {
 	miner        *miner.Miner
 	Mining       bool
 	MinerThreads int
-	AutoDAG      bool
-	autodagquit  chan bool
 	etherbase    common.Address
 	solcPath     string
 
@@ -173,7 +168,6 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		netVersionId:   config.NetworkId,
 		etherbase:      config.Etherbase,
 		MinerThreads:   config.MinerThreads,
-		AutoDAG:        config.AutoDAG,
 		solcPath:       config.SolcPath,
 	}
 
@@ -298,7 +292,7 @@ func CreatePoW(ctx *node.ServiceContext, config *Config) pow.PoW {
 		return pow.NewSharedEthash()
 	default:
 		return pow.NewFullEthash(ctx.ResolvePath(config.EthashCacheDir), config.EthashCachesInMem, config.EthashCachesOnDisk,
-			config.EthashDatasetDir, config.EthashDatasetsOnDisk)
+			config.EthashDatasetDir, config.EthashDatasetsInMem, config.EthashDatasetsOnDisk)
 	}
 }
 
@@ -414,9 +408,7 @@ func (s *Ethereum) Protocols() []p2p.Protocol {
 // Ethereum protocol implementation.
 func (s *Ethereum) Start(srvr *p2p.Server) error {
 	s.netRPCService = ethapi.NewPublicNetAPI(srvr, s.NetVersion())
-	if s.AutoDAG {
-		s.StartAutoDAG()
-	}
+
 	s.protocolManager.Start()
 	if s.lesServer != nil {
 		s.lesServer.Start(srvr)
@@ -439,8 +431,6 @@ func (s *Ethereum) Stop() error {
 	s.miner.Stop()
 	s.eventMux.Stop()
 
-	s.StopAutoDAG()
-
 	s.chainDb.Close()
 	close(s.shutdownChan)
 
@@ -451,74 +441,3 @@ func (s *Ethereum) Stop() error {
 func (s *Ethereum) WaitForShutdown() {
 	<-s.shutdownChan
 }
-
-// StartAutoDAG() spawns a go routine that checks the DAG every autoDAGcheckInterval
-// by default that is 10 times per epoch
-// in epoch n, if we past autoDAGepochHeight within-epoch blocks,
-// it calls ethash.MakeDAG  to pregenerate the DAG for the next epoch n+1
-// if it does not exist yet as well as remove the DAG for epoch n-1
-// the loop quits if autodagquit channel is closed, it can safely restart and
-// stop any number of times.
-// For any more sophisticated pattern of DAG generation, use CLI subcommand
-// makedag
-func (self *Ethereum) StartAutoDAG() {
-	if self.autodagquit != nil {
-		return // already started
-	}
-	go func() {
-		log.Info("Pre-generation of ethash DAG on", "dir", ethash.DefaultDir)
-		var nextEpoch uint64
-		timer := time.After(0)
-		self.autodagquit = make(chan bool)
-		for {
-			select {
-			case <-timer:
-				log.Info("Checking DAG availability", "dir", ethash.DefaultDir)
-				currentBlock := self.BlockChain().CurrentBlock().NumberU64()
-				thisEpoch := currentBlock / epochLength
-				if nextEpoch <= thisEpoch {
-					if currentBlock%epochLength > autoDAGepochHeight {
-						if thisEpoch > 0 {
-							previousDag, previousDagFull := dagFiles(thisEpoch - 1)
-							os.Remove(filepath.Join(ethash.DefaultDir, previousDag))
-							os.Remove(filepath.Join(ethash.DefaultDir, previousDagFull))
-							log.Info("Removed previous DAG", "epoch", thisEpoch-1, "dag", previousDag)
-						}
-						nextEpoch = thisEpoch + 1
-						dag, _ := dagFiles(nextEpoch)
-						if _, err := os.Stat(dag); os.IsNotExist(err) {
-							log.Info("Pre-generating next DAG", "epoch", nextEpoch, "dag", dag)
-							err := ethash.MakeDAG(nextEpoch*epochLength, "") // "" -> ethash.DefaultDir
-							if err != nil {
-								log.Error("Error generating DAG", "epoch", nextEpoch, "dag", dag, "err", err)
-								return
-							}
-						} else {
-							log.Warn("DAG already exists", "epoch", nextEpoch, "dag", dag)
-						}
-					}
-				}
-				timer = time.After(autoDAGcheckInterval)
-			case <-self.autodagquit:
-				return
-			}
-		}
-	}()
-}
-
-// stopAutoDAG stops automatic DAG pregeneration by quitting the loop
-func (self *Ethereum) StopAutoDAG() {
-	if self.autodagquit != nil {
-		close(self.autodagquit)
-		self.autodagquit = nil
-	}
-	log.Info("Pre-generation of ethash DAG off", "dir", ethash.DefaultDir)
-}
-
-// dagFiles(epoch) returns the two alternative DAG filenames (not a path)
-// 1) <revision>-<hex(seedhash[8])> 2) full-R<revision>-<hex(seedhash[8])>
-func dagFiles(epoch uint64) (string, string) {
-	seedHash, _ := ethash.GetSeedHash(epoch * epochLength)
-	dag := fmt.Sprintf("full-R%d-%x", ethashRevision, seedHash[:8])
-	return dag, "full-R" + dag
-}
diff --git a/internal/web3ext/web3ext.go b/internal/web3ext/web3ext.go
index e6bd18116..23112c1f1 100644
--- a/internal/web3ext/web3ext.go
+++ b/internal/web3ext/web3ext.go
@@ -399,20 +399,8 @@ web3._extend({
 			inputFormatter: [web3._extend.utils.fromDecimal]
 		}),
 		new web3._extend.Method({
-			name: 'startAutoDAG',
-			call: 'miner_startAutoDAG',
-			params: 0
-		}),
-		new web3._extend.Method({
-			name: 'stopAutoDAG',
-			call: 'miner_stopAutoDAG',
-			params: 0
-		}),
-		new web3._extend.Method({
-			name: 'makeDAG',
-			call: 'miner_makeDAG',
-			params: 1,
-			inputFormatter: [web3._extend.formatters.inputDefaultBlockNumberFormatter]
+			name: 'getHashrate',
+			call: 'miner_getHashrate'
 		})
 	],
 	properties: []
diff --git a/miner/miner.go b/miner/miner.go
index a91e1ef6b..dc0591b9a 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -164,7 +164,9 @@ func (self *Miner) HashRate() (tot int64) {
 	// aspects of the worker/locking up agents so we can get an accurate
 	// hashrate?
 	for agent := range self.worker.agents {
-		tot += agent.GetHashRate()
+		if _, ok := agent.(*CpuAgent); !ok {
+			tot += agent.GetHashRate()
+		}
 	}
 	return
 }
diff --git a/mobile/geth.go b/mobile/geth.go
index 872b482d3..62791652d 100644
--- a/mobile/geth.go
+++ b/mobile/geth.go
@@ -151,6 +151,9 @@ func NewNode(datadir string, config *NodeConfig) (stack *Node, _ error) {
 			GpobaseStepDown:         10,
 			GpobaseStepUp:           100,
 			GpobaseCorrectionFactor: 110,
+			EthashCacheDir:          "ethash",
+			EthashCachesInMem:       2,
+			EthashCachesOnDisk:      3,
 		}
 		if err := rawStack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
 			return les.New(ctx, ethConf)
diff --git a/pow/ethash.go b/pow/ethash.go
index 9dfeedb78..0af1904b6 100644
--- a/pow/ethash.go
+++ b/pow/ethash.go
@@ -22,7 +22,9 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
+	"math"
 	"math/big"
+	"math/rand"
 	"os"
 	"path/filepath"
 	"sync"
@@ -46,7 +48,7 @@ var (
 	maxUint256 = new(big.Int).Exp(big.NewInt(2), big.NewInt(256), big.NewInt(0))
 
 	// sharedEthash is a full instance that can be shared between multiple users.
-	sharedEthash = NewFullEthash("", 3, 0, "", 0)
+	sharedEthash = NewFullEthash("", 3, 0, "", 1, 0)
 
 	// algorithmRevision is the data structure version used for file naming.
 	algorithmRevision = 23
@@ -64,13 +66,13 @@ type cache struct {
 	lock  sync.Mutex // Ensures thread safety for updating the usage time
 }
 
-// generate ensures that the cache content is generates.
+// generate ensures that the cache content is generated before use.
 func (c *cache) generate(dir string, limit int, test bool) {
 	c.once.Do(func() {
 		// If we have a testing cache, generate and return
 		if test {
 			rawCache := generateCache(1024, seedHash(c.epoch*epochLength+1))
-			c.cache = prepare(uint64(len(rawCache)), bytes.NewReader(rawCache))
+			c.cache = prepare(1024, bytes.NewReader(rawCache))
 			return
 		}
 		// Full cache generation is needed, check cache dir for existing data
@@ -117,25 +119,112 @@ func (c *cache) generate(dir string, limit int, test bool) {
 	})
 }
 
+// dataset wraps an ethash dataset with some metadata to allow easier concurrent use.
+type dataset struct {
+	epoch   uint64     // Epoch for which this cache is relevant
+	dataset []uint32   // The actual cache data content
+	used    time.Time  // Timestamp of the last use for smarter eviction
+	once    sync.Once  // Ensures the cache is generated only once
+	lock    sync.Mutex // Ensures thread safety for updating the usage time
+}
+
+// generate ensures that the dataset content is generated before use.
+func (d *dataset) generate(dir string, limit int, test bool, discard bool) {
+	d.once.Do(func() {
+		// If we have a testing dataset, generate and return
+		if test {
+			rawCache := generateCache(1024, seedHash(d.epoch*epochLength+1))
+			intCache := prepare(1024, bytes.NewReader(rawCache))
+
+			rawDataset := generateDataset(32*1024, intCache)
+			d.dataset = prepare(32*1024, bytes.NewReader(rawDataset))
+
+			return
+		}
+		// Full dataset generation is needed, check dataset dir for existing data
+		csize := cacheSize(d.epoch*epochLength + 1)
+		dsize := datasetSize(d.epoch*epochLength + 1)
+		seed := seedHash(d.epoch*epochLength + 1)
+
+		path := filepath.Join(dir, fmt.Sprintf("full-R%d-%x", algorithmRevision, seed))
+		logger := log.New("seed", hexutil.Bytes(seed))
+
+		if dir != "" {
+			dump, err := os.Open(path)
+			if err == nil {
+				if !discard {
+					logger.Info("Loading ethash DAG from disk")
+					start := time.Now()
+					d.dataset = prepare(dsize, bufio.NewReader(dump))
+					logger.Info("Loaded ethash DAG from disk", "elapsed", common.PrettyDuration(time.Since(start)))
+				}
+				dump.Close()
+				return
+			}
+		}
+		// No previous disk dataset was available, generate on the fly
+		rawCache := generateCache(csize, seed)
+		intCache := prepare(csize, bytes.NewReader(rawCache))
+
+		rawDataset := generateDataset(dsize, intCache)
+		if !discard {
+			d.dataset = prepare(dsize, bytes.NewReader(rawDataset))
+		}
+		// If a dataset directory is given, attempt to serialize for next time
+		if dir != "" {
+			// Store the ethash dataset to disk
+			start := time.Now()
+			if err := os.MkdirAll(filepath.Dir(path), os.ModePerm); err != nil {
+				logger.Error("Failed to create ethash DAG dir", "err", err)
+			} else if err := ioutil.WriteFile(path, rawDataset, os.ModePerm); err != nil {
+				logger.Error("Failed to write ethash DAG to disk", "err", err)
+			} else {
+				logger.Info("Stored ethash DAG to disk", "elapsed", common.PrettyDuration(time.Since(start)))
+			}
+			// Iterate over all previous instances and delete old ones
+			for ep := int(d.epoch) - limit; ep >= 0; ep-- {
+				seed := seedHash(uint64(ep)*epochLength + 1)
+				path := filepath.Join(dir, fmt.Sprintf("full-R%d-%x", algorithmRevision, seed))
+				os.Remove(path)
+			}
+		}
+	})
+}
+
+// MakeCache generates a new ethash cache and optionally stores it to disk.
+func MakeCache(block uint64, dir string) {
+	c := cache{epoch: block/epochLength + 1}
+	c.generate(dir, math.MaxInt32, false)
+}
+
+// MakeDataset generates a new ethash dataset and optionally stores it to disk.
+func MakeDataset(block uint64, dir string) {
+	d := dataset{epoch: block/epochLength + 1}
+	d.generate(dir, math.MaxInt32, false, true)
+}
+
 // Ethash is a PoW data struture implementing the ethash algorithm.
 type Ethash struct {
 	cachedir     string // Data directory to store the verification caches
 	cachesinmem  int    // Number of caches to keep in memory
 	cachesondisk int    // Number of caches to keep on disk
 	dagdir       string // Data directory to store full mining datasets
+	dagsinmem    int    // Number of mining datasets to keep in memory
 	dagsondisk   int    // Number of mining datasets to keep on disk
 
-	caches map[uint64]*cache // In memory caches to avoid regenerating too often
-	future *cache            // Pre-generated cache for the estimated future epoch
-	lock   sync.Mutex        // Ensures thread safety for the in-memory caches
+	caches   map[uint64]*cache   // In memory caches to avoid regenerating too often
+	fcache   *cache              // Pre-generated cache for the estimated future epoch
+	datasets map[uint64]*dataset // In memory datasets to avoid regenerating too often
+	fdataset *dataset            // Pre-generated dataset for the estimated future epoch
+	lock     sync.Mutex          // Ensures thread safety for the in-memory caches
 
-	hashrate *metrics.StandardMeter // Meter tracking the average hashrate
+	hashrate metrics.Meter // Meter tracking the average hashrate
 
 	tester bool // Flag whether to use a smaller test dataset
 }
 
 // NewFullEthash creates a full sized ethash PoW scheme.
-func NewFullEthash(cachedir string, cachesinmem, cachesondisk int, dagdir string, dagsondisk int) PoW {
+func NewFullEthash(cachedir string, cachesinmem, cachesondisk int, dagdir string, dagsinmem, dagsondisk int) PoW {
 	if cachesinmem <= 0 {
 		log.Warn("One ethash cache must alwast be in memory", "requested", cachesinmem)
 		cachesinmem = 1
@@ -151,8 +240,11 @@ func NewFullEthash(cachedir string, cachesinmem, cachesondisk int, dagdir string
 		cachesinmem:  cachesinmem,
 		cachesondisk: cachesondisk,
 		dagdir:       dagdir,
+		dagsinmem:    dagsinmem,
 		dagsondisk:   dagsondisk,
 		caches:       make(map[uint64]*cache),
+		datasets:     make(map[uint64]*dataset),
+		hashrate:     metrics.NewMeter(),
 	}
 }
 
@@ -162,7 +254,9 @@ func NewTestEthash() PoW {
 	return &Ethash{
 		cachesinmem: 1,
 		caches:      make(map[uint64]*cache),
+		datasets:    make(map[uint64]*dataset),
 		tester:      true,
+		hashrate:    metrics.NewMeter(),
 	}
 }
 
@@ -181,7 +275,7 @@ func (ethash *Ethash) Verify(block Block) error {
 		// Go < 1.7 cannot calculate new cache/dataset sizes (no fast prime check)
 		return ErrNonceOutOfRange
 	}
-	// Ensure twe have a valid difficulty for the block
+	// Ensure that we have a valid difficulty for the block
 	difficulty := block.Difficulty()
 	if difficulty.Sign() <= 0 {
 		return ErrInvalidDifficulty
@@ -228,9 +322,9 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 			log.Debug("Evicted ethash cache", "epoch", evict.epoch, "used", evict.used)
 		}
 		// If we have the new cache pre-generated, use that, otherwise create a new one
-		if ethash.future != nil && ethash.future.epoch == epoch {
+		if ethash.fcache != nil && ethash.fcache.epoch == epoch {
 			log.Debug("Using pre-generated cache", "epoch", epoch)
-			current, ethash.future = ethash.future, nil
+			current, ethash.fcache = ethash.fcache, nil
 		} else {
 			log.Debug("Requiring new ethash cache", "epoch", epoch)
 			current = &cache{epoch: epoch}
@@ -238,10 +332,10 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 		ethash.caches[epoch] = current
 
 		// If we just used up the future cache, or need a refresh, regenerate
-		if ethash.future == nil || ethash.future.epoch <= epoch {
+		if ethash.fcache == nil || ethash.fcache.epoch <= epoch {
 			log.Debug("Requiring new future ethash cache", "epoch", epoch+1)
 			future = &cache{epoch: epoch + 1}
-			ethash.future = future
+			ethash.fcache = future
 		}
 	}
 	current.used = time.Now()
@@ -254,7 +348,7 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 	current.used = time.Now()
 	current.lock.Unlock()
 
-	// If we exhusted the future cache, now's a goot time to regenerate it
+	// If we exhausted the future cache, now's a good time to regenerate it
 	if future != nil {
 		go future.generate(ethash.cachedir, ethash.cachesondisk, ethash.tester)
 	}
@@ -264,7 +358,102 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 // Search implements PoW, attempting to find a nonce that satisfies the block's
 // difficulty requirements.
 func (ethash *Ethash) Search(block Block, stop <-chan struct{}) (uint64, []byte) {
-	return 0, nil
+	// Extract some data from the block
+	var (
+		hash   = block.HashNoNonce().Bytes()
+		diff   = block.Difficulty()
+		target = new(big.Int).Div(maxUint256, diff)
+	)
+	// Retrieve the mining dataset
+	dataset, size := ethash.dataset(block.NumberU64()), datasetSize(block.NumberU64())
+
+	// Start generating random nonces until we abort or find a good one
+	var (
+		attempts int64
+
+		rand  = rand.New(rand.NewSource(time.Now().UnixNano()))
+		nonce = uint64(rand.Int63())
+	)
+	for {
+		select {
+		case <-stop:
+			// Mining terminated, update stats and abort
+			ethash.hashrate.Mark(attempts)
+			return 0, nil
+
+		default:
+			// We don't have to update hash rate on every nonce, so update after after 2^X nonces
+			attempts++
+			if (attempts % (1 << 15)) == 0 {
+				ethash.hashrate.Mark(attempts)
+				attempts = 0
+			}
+			// Compute the PoW value of this nonce
+			digest, result := hashimotoFull(size, dataset, hash, nonce)
+			if new(big.Int).SetBytes(result).Cmp(target) <= 0 {
+				return nonce, digest
+			}
+			nonce++
+		}
+	}
+}
+
+// dataset tries to retrieve a mining dataset for the specified block number
+// by first checking against a list of in-memory datasets, then against DAGs
+// stored on disk, and finally generating one if none can be found.
+func (ethash *Ethash) dataset(block uint64) []uint32 {
+	epoch := block / epochLength
+
+	// If we have a PoW for that epoch, use that
+	ethash.lock.Lock()
+
+	current, future := ethash.datasets[epoch], (*dataset)(nil)
+	if current == nil {
+		// No in-memory dataset, evict the oldest if the dataset limit was reached
+		for len(ethash.datasets) >= ethash.dagsinmem {
+			var evict *dataset
+			for _, dataset := range ethash.datasets {
+				if evict == nil || evict.used.After(dataset.used) {
+					evict = dataset
+				}
+			}
+			delete(ethash.datasets, evict.epoch)
+
+			log.Debug("Evicted ethash dataset", "epoch", evict.epoch, "used", evict.used)
+		}
+		// If we have the new cache pre-generated, use that, otherwise create a new one
+		if ethash.fdataset != nil && ethash.fdataset.epoch == epoch {
+			log.Debug("Using pre-generated dataset", "epoch", epoch)
+			current = &dataset{epoch: ethash.fdataset.epoch} // Reload from disk
+			ethash.fdataset = nil
+		} else {
+			log.Debug("Requiring new ethash dataset", "epoch", epoch)
+			current = &dataset{epoch: epoch}
+		}
+		ethash.datasets[epoch] = current
+
+		// If we just used up the future dataset, or need a refresh, regenerate
+		if ethash.fdataset == nil || ethash.fdataset.epoch <= epoch {
+			log.Debug("Requiring new future ethash dataset", "epoch", epoch+1)
+			future = &dataset{epoch: epoch + 1}
+			ethash.fdataset = future
+		}
+	}
+	current.used = time.Now()
+	ethash.lock.Unlock()
+
+	// Wait for generation finish, bump the timestamp and finalize the cache
+	current.generate(ethash.dagdir, ethash.dagsondisk, ethash.tester, false)
+
+	current.lock.Lock()
+	current.used = time.Now()
+	current.lock.Unlock()
+
+	// If we exhausted the future dataset, now's a good time to regenerate it
+	if future != nil {
+		go future.generate(ethash.dagdir, ethash.dagsondisk, ethash.tester, true) // Discard results from memorys
+	}
+	return current.dataset
 }
 
 // Hashrate implements PoW, returning the measured rate of the search invocations
diff --git a/vendor/github.com/ethereum/ethash/CMakeLists.txt b/vendor/github.com/ethereum/ethash/CMakeLists.txt
deleted file mode 100644
index 807c43e96..000000000
--- a/vendor/github.com/ethereum/ethash/CMakeLists.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-cmake_minimum_required(VERSION 2.8.7)
-project(ethash)
-
-set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/modules/")
-set(ETHHASH_LIBS ethash)
-
-if (WIN32 AND WANT_CRYPTOPP)
-	add_subdirectory(cryptopp)
-endif()
-
-add_subdirectory(src/libethash)
-
-add_subdirectory(src/benchmark EXCLUDE_FROM_ALL)
-add_subdirectory(test/c)
diff --git a/vendor/github.com/ethereum/ethash/MANIFEST.in b/vendor/github.com/ethereum/ethash/MANIFEST.in
deleted file mode 100644
index 74e73c8be..000000000
--- a/vendor/github.com/ethereum/ethash/MANIFEST.in
+++ /dev/null
@@ -1,17 +0,0 @@
-include setup.py
-
-# C sources
-include src/libethash/internal.c
-include src/libethash/sha3.c
-include src/libethash/util.c
-include src/python/core.c
-
-# Headers
-include src/libethash/compiler.h
-include src/libethash/data_sizes.h
-include src/libethash/endian.h
-include src/libethash/ethash.h
-include src/libethash/fnv.h
-include src/libethash/internal.h
-include src/libethash/sha3.h
-include src/libethash/util.h
diff --git a/vendor/github.com/ethereum/ethash/Makefile b/vendor/github.com/ethereum/ethash/Makefile
deleted file mode 100644
index 741d3b56d..000000000
--- a/vendor/github.com/ethereum/ethash/Makefile
+++ /dev/null
@@ -1,6 +0,0 @@
-.PHONY: clean test
-test:
-	./test/test.sh
-
-clean:
-	rm -rf *.so pyethash.egg-info/ build/ test/python/python-virtual-env/ test/c/build/ pyethash.so test/python/*.pyc dist/ MANIFEST
diff --git a/vendor/github.com/ethereum/ethash/README.md b/vendor/github.com/ethereum/ethash/README.md
deleted file mode 100644
index 2b2c3b544..000000000
--- a/vendor/github.com/ethereum/ethash/README.md
+++ /dev/null
@@ -1,22 +0,0 @@
-[![Build Status](https://travis-ci.org/ethereum/ethash.svg?branch=master)](https://travis-ci.org/ethereum/ethash)
-[![Windows Build Status](https://ci.appveyor.com/api/projects/status/github/debris/ethash?branch=master&svg=true)](https://ci.appveyor.com/project/debris/ethash-nr37r/branch/master)
-
-# Ethash
-
-For details on this project, please see the Ethereum wiki:
-https://github.com/ethereum/wiki/wiki/Ethash
-
-### Coding Style for C++ code:
-
-Follow the same exact style as in [cpp-ethereum](https://github.com/ethereum/cpp-ethereum/blob/develop/CodingStandards.txt)
-
-### Coding Style for C code:
-
-The main thing above all is code consistency.
-
-- Tabs for indentation. A tab is 4 spaces
-- Try to stick to the [K&R](http://en.wikipedia.org/wiki/Indent_style#K.26R_style),
-  especially for the C code.
-- Keep the line lengths reasonable. No hard limit on 80 characters but don't go further
-  than 110. Some people work with multiple buffers next to each other.
-  Make them like you :)
diff --git a/vendor/github.com/ethereum/ethash/Vagrantfile b/vendor/github.com/ethereum/ethash/Vagrantfile
deleted file mode 100644
index 03891653f..000000000
--- a/vendor/github.com/ethereum/ethash/Vagrantfile
+++ /dev/null
@@ -1,7 +0,0 @@
-# -*- mode: ruby -*-
-# vi: set ft=ruby :
-
-Vagrant.configure(2) do |config|
-  config.vm.box = "Ubuntu 12.04"
-  config.vm.box_url = "https://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-amd64-vagrant-disk1.box"
-end
diff --git a/vendor/github.com/ethereum/ethash/appveyor.yml b/vendor/github.com/ethereum/ethash/appveyor.yml
deleted file mode 100644
index ac36a0626..000000000
--- a/vendor/github.com/ethereum/ethash/appveyor.yml
+++ /dev/null
@@ -1,43 +0,0 @@
-version: 1.0.0.{build}
-
-environment:
-    BOOST_ROOT: "c:/projects/ethash/deps/boost"
-
-branches:
-    only:
-        - master
-        - develop
-
-os: Windows Server 2012 R2
-
-clone_folder: c:\projects\ethash
-
-#platform: Any CPU
-#configuration: Debug
-
-install:
-    # by default, all script lines are interpreted as batch
-
-# scripts to run before build
-before_build:
-    - echo "Downloading boost..."
-    - mkdir c:\projects\ethash\deps
-    - cd c:\projects\ethash\deps
-    - curl -O https://build.ethdev.com/builds/windows-precompiled/boost.tar.gz
-    - echo "Unzipping boost..."
-    - 7z x boost.tar.gz > nul
-    - 7z x boost.tar > nul
-    - ls
-    - echo "Running cmake..."
-    - cd c:\projects\ethash
-    - cmake .
-
-build:
-    project: ALL_BUILD.vcxproj      # path to Visual Studio solution or project
-
-after_build:
-    - echo "Running tests..."
-    - cd c:\projects\ethash\test\c\Debug
-    - Test.exe
-    - echo "Finished!"
-
diff --git a/vendor/github.com/ethereum/ethash/ethash.go b/vendor/github.com/ethereum/ethash/ethash.go
deleted file mode 100644
index 8e5cd8128..000000000
--- a/vendor/github.com/ethereum/ethash/ethash.go
+++ /dev/null
@@ -1,440 +0,0 @@
-// Copyright 2015 The go-ethereum Authors
-// Copyright 2015 Lefteris Karapetsas <lefteris@refu.co>
-// Copyright 2015 Matthew Wampler-Doty <matthew.wampler.doty@gmail.com>
-// 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 ethash
-
-/*
-#include "src/libethash/internal.h"
-
-int ethashGoCallback_cgo(unsigned);
-*/
-import "C"
-
-import (
-	"errors"
-	"fmt"
-	"io/ioutil"
-	"math/big"
-	"math/rand"
-	"os"
-	"os/user"
-	"path/filepath"
-	"runtime"
-	"sync"
-	"sync/atomic"
-	"time"
-	"unsafe"
-
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/log"
-	"github.com/ethereum/go-ethereum/pow"
-)
-
-var (
-	maxUint256  = new(big.Int).Exp(big.NewInt(2), big.NewInt(256), big.NewInt(0))
-	sharedLight = new(Light)
-)
-
-const (
-	epochLength         uint64     = 30000
-	cacheSizeForTesting C.uint64_t = 1024
-	dagSizeForTesting   C.uint64_t = 1024 * 32
-)
-
-var DefaultDir = defaultDir()
-
-func defaultDir() string {
-	home := os.Getenv("HOME")
-	if user, err := user.Current(); err == nil {
-		home = user.HomeDir
-	}
-	if runtime.GOOS == "windows" {
-		return filepath.Join(home, "AppData", "Ethash")
-	}
-	return filepath.Join(home, ".ethash")
-}
-
-// cache wraps an ethash_light_t with some metadata
-// and automatic memory management.
-type cache struct {
-	epoch uint64
-	used  time.Time
-	test  bool
-
-	gen sync.Once // ensures cache is only generated once.
-	ptr *C.struct_ethash_light
-}
-
-// generate creates the actual cache. it can be called from multiple
-// goroutines. the first call will generate the cache, subsequent
-// calls wait until it is generated.
-func (cache *cache) generate() {
-	cache.gen.Do(func() {
-		started := time.Now()
-		seedHash := makeSeedHash(cache.epoch)
-		log.Debug(fmt.Sprintf("Generating cache for epoch %d (%x)", cache.epoch, seedHash))
-		size := C.ethash_get_cachesize(C.uint64_t(cache.epoch * epochLength))
-		if cache.test {
-			size = cacheSizeForTesting
-		}
-		cache.ptr = C.ethash_light_new_internal(size, (*C.ethash_h256_t)(unsafe.Pointer(&seedHash[0])))
-		runtime.SetFinalizer(cache, freeCache)
-		log.Debug(fmt.Sprintf("Done generating cache for epoch %d, it took %v", cache.epoch, time.Since(started)))
-	})
-}
-
-func freeCache(cache *cache) {
-	C.ethash_light_delete(cache.ptr)
-	cache.ptr = nil
-}
-
-func (cache *cache) compute(dagSize uint64, hash common.Hash, nonce uint64) (ok bool, mixDigest, result common.Hash) {
-	ret := C.ethash_light_compute_internal(cache.ptr, C.uint64_t(dagSize), hashToH256(hash), C.uint64_t(nonce))
-	// Make sure cache is live until after the C call.
-	// This is important because a GC might happen and execute
-	// the finalizer before the call completes.
-	_ = cache
-	return bool(ret.success), h256ToHash(ret.mix_hash), h256ToHash(ret.result)
-}
-
-// Light implements the Verify half of the proof of work. It uses a few small
-// in-memory caches to verify the nonces found by Full.
-type Light struct {
-	test bool // If set, use a smaller cache size
-
-	mu     sync.Mutex        // Protects the per-epoch map of verification caches
-	caches map[uint64]*cache // Currently maintained verification caches
-	future *cache            // Pre-generated cache for the estimated future DAG
-
-	NumCaches int // Maximum number of caches to keep before eviction (only init, don't modify)
-}
-
-// Verify checks whether the block's nonce is valid.
-func (l *Light) Verify(block pow.Block) bool {
-	// TODO: do ethash_quick_verify before getCache in order
-	// to prevent DOS attacks.
-	blockNum := block.NumberU64()
-	if blockNum >= epochLength*2048 {
-		log.Debug(fmt.Sprintf("block number %d too high, limit is %d", epochLength*2048))
-		return false
-	}
-
-	difficulty := block.Difficulty()
-	/* Cannot happen if block header diff is validated prior to PoW, but can
-		 happen if PoW is checked first due to parallel PoW checking.
-		 We could check the minimum valid difficulty but for SoC we avoid (duplicating)
-	   Ethereum protocol consensus rules here which are not in scope of Ethash
-	*/
-	if difficulty.Cmp(common.Big0) == 0 {
-		log.Debug(fmt.Sprintf("invalid block difficulty"))
-		return false
-	}
-
-	cache := l.getCache(blockNum)
-	dagSize := C.ethash_get_datasize(C.uint64_t(blockNum))
-	if l.test {
-		dagSize = dagSizeForTesting
-	}
-	// Recompute the hash using the cache.
-	ok, mixDigest, result := cache.compute(uint64(dagSize), block.HashNoNonce(), block.Nonce())
-	if !ok {
-		return false
-	}
-
-	// avoid mixdigest malleability as it's not included in a block's "hashNononce"
-	if block.MixDigest() != mixDigest {
-		return false
-	}
-
-	// The actual check.
-	target := new(big.Int).Div(maxUint256, difficulty)
-	return result.Big().Cmp(target) <= 0
-}
-
-func h256ToHash(in C.ethash_h256_t) common.Hash {
-	return *(*common.Hash)(unsafe.Pointer(&in.b))
-}
-
-func hashToH256(in common.Hash) C.ethash_h256_t {
-	return C.ethash_h256_t{b: *(*[32]C.uint8_t)(unsafe.Pointer(&in[0]))}
-}
-
-func (l *Light) getCache(blockNum uint64) *cache {
-	var c *cache
-	epoch := blockNum / epochLength
-
-	// If we have a PoW for that epoch, use that
-	l.mu.Lock()
-	if l.caches == nil {
-		l.caches = make(map[uint64]*cache)
-	}
-	if l.NumCaches == 0 {
-		l.NumCaches = 3
-	}
-	c = l.caches[epoch]
-	if c == nil {
-		// No cached DAG, evict the oldest if the cache limit was reached
-		if len(l.caches) >= l.NumCaches {
-			var evict *cache
-			for _, cache := range l.caches {
-				if evict == nil || evict.used.After(cache.used) {
-					evict = cache
-				}
-			}
-			log.Debug(fmt.Sprintf("Evicting DAG for epoch %d in favour of epoch %d", evict.epoch, epoch))
-			delete(l.caches, evict.epoch)
-		}
-		// If we have the new DAG pre-generated, use that, otherwise create a new one
-		if l.future != nil && l.future.epoch == epoch {
-			log.Debug(fmt.Sprintf("Using pre-generated DAG for epoch %d", epoch))
-			c, l.future = l.future, nil
-		} else {
-			log.Debug(fmt.Sprintf("No pre-generated DAG available, creating new for epoch %d", epoch))
-			c = &cache{epoch: epoch, test: l.test}
-		}
-		l.caches[epoch] = c
-
-		// If we just used up the future cache, or need a refresh, regenerate
-		if l.future == nil || l.future.epoch <= epoch {
-			log.Debug(fmt.Sprintf("Pre-generating DAG for epoch %d", epoch+1))
-			l.future = &cache{epoch: epoch + 1, test: l.test}
-			go l.future.generate()
-		}
-	}
-	c.used = time.Now()
-	l.mu.Unlock()
-
-	// Wait for generation finish and return the cache
-	c.generate()
-	return c
-}
-
-// dag wraps an ethash_full_t with some metadata
-// and automatic memory management.
-type dag struct {
-	epoch uint64
-	test  bool
-	dir   string
-
-	gen sync.Once // ensures DAG is only generated once.
-	ptr *C.struct_ethash_full
-}
-
-// generate creates the actual DAG. it can be called from multiple
-// goroutines. the first call will generate the DAG, subsequent
-// calls wait until it is generated.
-func (d *dag) generate() {
-	d.gen.Do(func() {
-		var (
-			started   = time.Now()
-			seedHash  = makeSeedHash(d.epoch)
-			blockNum  = C.uint64_t(d.epoch * epochLength)
-			cacheSize = C.ethash_get_cachesize(blockNum)
-			dagSize   = C.ethash_get_datasize(blockNum)
-		)
-		if d.test {
-			cacheSize = cacheSizeForTesting
-			dagSize = dagSizeForTesting
-		}
-		if d.dir == "" {
-			d.dir = DefaultDir
-		}
-		log.Info(fmt.Sprintf("Generating DAG for epoch %d (size %d) (%x)", d.epoch, dagSize, seedHash))
-		// Generate a temporary cache.
-		// TODO: this could share the cache with Light
-		cache := C.ethash_light_new_internal(cacheSize, (*C.ethash_h256_t)(unsafe.Pointer(&seedHash[0])))
-		defer C.ethash_light_delete(cache)
-		// Generate the actual DAG.
-		d.ptr = C.ethash_full_new_internal(
-			C.CString(d.dir),
-			hashToH256(seedHash),
-			dagSize,
-			cache,
-			(C.ethash_callback_t)(unsafe.Pointer(C.ethashGoCallback_cgo)),
-		)
-		if d.ptr == nil {
-			panic("ethash_full_new IO or memory error")
-		}
-		runtime.SetFinalizer(d, freeDAG)
-		log.Info(fmt.Sprintf("Done generating DAG for epoch %d, it took %v", d.epoch, time.Since(started)))
-	})
-}
-
-func freeDAG(d *dag) {
-	C.ethash_full_delete(d.ptr)
-	d.ptr = nil
-}
-
-func (d *dag) Ptr() unsafe.Pointer {
-	return unsafe.Pointer(d.ptr.data)
-}
-
-//export ethashGoCallback
-func ethashGoCallback(percent C.unsigned) C.int {
-	log.Info(fmt.Sprintf("Generating DAG: %d%%", percent))
-	return 0
-}
-
-// MakeDAG pre-generates a DAG file for the given block number in the
-// given directory. If dir is the empty string, the default directory
-// is used.
-func MakeDAG(blockNum uint64, dir string) error {
-	d := &dag{epoch: blockNum / epochLength, dir: dir}
-	if blockNum >= epochLength*2048 {
-		return fmt.Errorf("block number too high, limit is %d", epochLength*2048)
-	}
-	d.generate()
-	if d.ptr == nil {
-		return errors.New("failed")
-	}
-	return nil
-}
-
-// Full implements the Search half of the proof of work.
-type Full struct {
-	Dir string // use this to specify a non-default DAG directory
-
-	test     bool // if set use a smaller DAG size
-	turbo    bool
-	hashRate int32
-
-	mu      sync.Mutex // protects dag
-	current *dag       // current full DAG
-}
-
-func (pow *Full) getDAG(blockNum uint64) (d *dag) {
-	epoch := blockNum / epochLength
-	pow.mu.Lock()
-	if pow.current != nil && pow.current.epoch == epoch {
-		d = pow.current
-	} else {
-		d = &dag{epoch: epoch, test: pow.test, dir: pow.Dir}
-		pow.current = d
-	}
-	pow.mu.Unlock()
-	// wait for it to finish generating.
-	d.generate()
-	return d
-}
-
-func (pow *Full) Search(block pow.Block, stop <-chan struct{}, index int) (nonce uint64, mixDigest []byte) {
-	dag := pow.getDAG(block.NumberU64())
-
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
-	diff := block.Difficulty()
-
-	i := int64(0)
-	starti := i
-	start := time.Now().UnixNano()
-	previousHashrate := int32(0)
-
-	nonce = uint64(r.Int63())
-	hash := hashToH256(block.HashNoNonce())
-	target := new(big.Int).Div(maxUint256, diff)
-	for {
-		select {
-		case <-stop:
-			atomic.AddInt32(&pow.hashRate, -previousHashrate)
-			return 0, nil
-		default:
-			i++
-
-			// we don't have to update hash rate on every nonce, so update after
-			// first nonce check and then after 2^X nonces
-			if i == 2 || ((i % (1 << 16)) == 0) {
-				elapsed := time.Now().UnixNano() - start
-				hashes := (float64(1e9) / float64(elapsed)) * float64(i-starti)
-				hashrateDiff := int32(hashes) - previousHashrate
-				previousHashrate = int32(hashes)
-				atomic.AddInt32(&pow.hashRate, hashrateDiff)
-			}
-
-			ret := C.ethash_full_compute(dag.ptr, hash, C.uint64_t(nonce))
-			result := h256ToHash(ret.result).Big()
-
-			// TODO: disagrees with the spec https://github.com/ethereum/wiki/wiki/Ethash#mining
-			if ret.success && result.Cmp(target) <= 0 {
-				mixDigest = C.GoBytes(unsafe.Pointer(&ret.mix_hash), C.int(32))
-				atomic.AddInt32(&pow.hashRate, -previousHashrate)
-				return nonce, mixDigest
-			}
-			nonce += 1
-		}
-
-		if !pow.turbo {
-			time.Sleep(20 * time.Microsecond)
-		}
-	}
-}
-
-func (pow *Full) GetHashrate() int64 {
-	return int64(atomic.LoadInt32(&pow.hashRate))
-}
-
-func (pow *Full) Turbo(on bool) {
-	// TODO: this needs to use an atomic operation.
-	pow.turbo = on
-}
-
-// Ethash combines block verification with Light and
-// nonce searching with Full into a single proof of work.
-type Ethash struct {
-	*Light
-	*Full
-}
-
-// New creates an instance of the proof of work.
-func New() *Ethash {
-	return &Ethash{new(Light), &Full{turbo: true}}
-}
-
-// NewShared creates an instance of the proof of work., where a single instance
-// of the Light cache is shared across all instances created with NewShared.
-func NewShared() *Ethash {
-	return &Ethash{sharedLight, &Full{turbo: true}}
-}
-
-// NewForTesting creates a proof of work for use in unit tests.
-// It uses a smaller DAG and cache size to keep test times low.
-// DAG files are stored in a temporary directory.
-//
-// Nonces found by a testing instance are not verifiable with a
-// regular-size cache.
-func NewForTesting() (*Ethash, error) {
-	dir, err := ioutil.TempDir("", "ethash-test")
-	if err != nil {
-		return nil, err
-	}
-	return &Ethash{&Light{test: true}, &Full{Dir: dir, test: true}}, nil
-}
-
-func GetSeedHash(blockNum uint64) ([]byte, error) {
-	if blockNum >= epochLength*2048 {
-		return nil, fmt.Errorf("block number too high, limit is %d", epochLength*2048)
-	}
-	sh := makeSeedHash(blockNum / epochLength)
-	return sh[:], nil
-}
-
-func makeSeedHash(epoch uint64) (sh common.Hash) {
-	for ; epoch > 0; epoch-- {
-		sh = crypto.Sha3Hash(sh[:])
-	}
-	return sh
-}
diff --git a/vendor/github.com/ethereum/ethash/ethashc.go b/vendor/github.com/ethereum/ethash/ethashc.go
deleted file mode 100644
index 1d2ba1613..000000000
--- a/vendor/github.com/ethereum/ethash/ethashc.go
+++ /dev/null
@@ -1,51 +0,0 @@
-// 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 ethash
-
-/*
- -mno-stack-arg-probe disables stack probing which avoids the function
- __chkstk_ms being linked. this avoids a clash of this symbol as we also
- separately link the secp256k1 lib which ends up defining this symbol
-
- 1. https://gcc.gnu.org/onlinedocs/gccint/Stack-Checking.html
- 2. https://groups.google.com/forum/#!msg/golang-dev/v1bziURSQ4k/88fXuJ24e-gJ
- 3. https://groups.google.com/forum/#!topic/golang-nuts/VNP6Mwz_B6o
-
-*/
-
-/*
-#cgo CFLAGS: -std=gnu99 -Wall
-#cgo windows CFLAGS: -mno-stack-arg-probe
-#cgo LDFLAGS: -lm
-
-#include "src/libethash/internal.c"
-#include "src/libethash/sha3.c"
-#include "src/libethash/io.c"
-
-#ifdef _WIN32
-#	include "src/libethash/io_win32.c"
-#	include "src/libethash/mmap_win32.c"
-#else
-#	include "src/libethash/io_posix.c"
-#endif
-
-// 'gateway function' for calling back into go.
-extern int ethashGoCallback(unsigned);
-int ethashGoCallback_cgo(unsigned percent) { return ethashGoCallback(percent); }
-
-*/
-import "C"
diff --git a/vendor/github.com/ethereum/ethash/setup.py b/vendor/github.com/ethereum/ethash/setup.py
deleted file mode 100755
index 18aa20f6d..000000000
--- a/vendor/github.com/ethereum/ethash/setup.py
+++ /dev/null
@@ -1,47 +0,0 @@
-#!/usr/bin/env python
-import os
-from distutils.core import setup, Extension
-sources = [
-    'src/python/core.c',
-    'src/libethash/io.c',
-    'src/libethash/internal.c',
-    'src/libethash/sha3.c']
-if os.name == 'nt':
-    sources += [
-        'src/libethash/util_win32.c',
-        'src/libethash/io_win32.c',
-        'src/libethash/mmap_win32.c',
-    ]
-else:
-    sources += [
-        'src/libethash/io_posix.c'
-    ]
-depends = [
-    'src/libethash/ethash.h',
-    'src/libethash/compiler.h',
-    'src/libethash/data_sizes.h',
-    'src/libethash/endian.h',
-    'src/libethash/ethash.h',
-    'src/libethash/io.h',
-    'src/libethash/fnv.h',
-    'src/libethash/internal.h',
-    'src/libethash/sha3.h',
-    'src/libethash/util.h',
-]
-pyethash = Extension('pyethash',
-                     sources=sources,
-                     depends=depends,
-                     extra_compile_args=["-Isrc/", "-std=gnu99", "-Wall"])
-
-setup(
-    name='pyethash',
-    author="Matthew Wampler-Doty",
-    author_email="matthew.wampler.doty@gmail.com",
-    license='GPL',
-    version='0.1.23',
-    url='https://github.com/ethereum/ethash',
-    download_url='https://github.com/ethereum/ethash/tarball/v23',
-    description=('Python wrappers for ethash, the ethereum proof of work'
-                 'hashing function'),
-    ext_modules=[pyethash],
-)
diff --git a/vendor/vendor.json b/vendor/vendor.json
index e28ab243b..eb6d3ac62 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -35,12 +35,6 @@
 			"revisionTime": "2016-10-29T20:57:26Z"
 		},
 		{
-			"checksumSHA1": "HdOu+ISNyVWMyBao7vDI21uZH6U=",
-			"path": "github.com/ethereum/ethash",
-			"revision": "214d4c008e101d4f7b18318389fb8c2e00323f24",
-			"revisionTime": "2016-10-25T09:19:48Z"
-		},
-		{
 			"checksumSHA1": "7oFpbmDfGobwKsFLIf6wMUvVoKw=",
 			"path": "github.com/fatih/color",
 			"revision": "5ec5d9d3c2cf82e9688b34e9bc27a94d616a7193",