Merge branch 'master' into abi-offset-fixed-arrays

8 files changed, 103 insertions, 68 deletions

diff --git a/consensus/clique/clique.go b/consensus/clique/clique.go
index 8d6cf653d..a98058141 100644
--- a/consensus/clique/clique.go
+++ b/consensus/clique/clique.go
@@ -125,6 +125,11 @@ var (
 
 	// errUnauthorized is returned if a header is signed by a non-authorized entity.
 	errUnauthorized = errors.New("unauthorized")
+
+	// errWaitTransactions is returned if an empty block is attempted to be sealed
+	// on an instant chain (0 second period). It's important to refuse these as the
+	// block reward is zero, so an empty block just bloats the chain... fast.
+	errWaitTransactions = errors.New("waiting for transactions")
 )
 
 // SignerFn is a signer callback function to request a hash to be signed by a
@@ -211,9 +216,6 @@ func New(config *params.CliqueConfig, db ethdb.Database) *Clique {
 	if conf.Epoch == 0 {
 		conf.Epoch = epochLength
 	}
-	if conf.Period == 0 {
-		conf.Period = blockPeriod
-	}
 	// Allocate the snapshot caches and create the engine
 	recents, _ := lru.NewARC(inmemorySnapshots)
 	signatures, _ := lru.NewARC(inmemorySignatures)
@@ -599,6 +601,10 @@ func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, stop <-ch
 	if number == 0 {
 		return nil, errUnknownBlock
 	}
+	// For 0-period chains, refuse to seal empty blocks (no reward but would spin sealing)
+	if c.config.Period == 0 && len(block.Transactions()) == 0 {
+		return nil, errWaitTransactions
+	}
 	// Don't hold the signer fields for the entire sealing procedure
 	c.lock.RLock()
 	signer, signFn := c.signer, c.signFn
@@ -624,7 +630,7 @@ func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, stop <-ch
 		}
 	}
 	// Sweet, the protocol permits us to sign the block, wait for our time
-	delay := time.Unix(header.Time.Int64(), 0).Sub(time.Now())
+	delay := time.Unix(header.Time.Int64(), 0).Sub(time.Now()) // nolint: gosimple
 	if header.Difficulty.Cmp(diffNoTurn) == 0 {
 		// It's not our turn explicitly to sign, delay it a bit
 		wiggle := time.Duration(len(snap.Signers)/2+1) * wiggleTime
diff --git a/consensus/clique/snapshot_test.go b/consensus/clique/snapshot_test.go
index a1717d799..8b51e6e09 100644
--- a/consensus/clique/snapshot_test.go
+++ b/consensus/clique/snapshot_test.go
@@ -74,7 +74,7 @@ type testerChainReader struct {
 	db ethdb.Database
 }
 
-func (r *testerChainReader) Config() *params.ChainConfig                 { return params.AllProtocolChanges }
+func (r *testerChainReader) Config() *params.ChainConfig                 { return params.AllCliqueProtocolChanges }
 func (r *testerChainReader) CurrentHeader() *types.Header                { panic("not supported") }
 func (r *testerChainReader) GetHeader(common.Hash, uint64) *types.Header { panic("not supported") }
 func (r *testerChainReader) GetBlock(common.Hash, uint64) *types.Block   { panic("not supported") }
diff --git a/consensus/ethash/algorithm.go b/consensus/ethash/algorithm.go
index a737bc636..76f19252f 100644
--- a/consensus/ethash/algorithm.go
+++ b/consensus/ethash/algorithm.go
@@ -102,7 +102,7 @@ func generateCache(dest []uint32, epoch uint64, seed []byte) {
 	header.Cap *= 4
 	cache := *(*[]byte)(unsafe.Pointer(&header))
 
-	// Calculate the number of thoretical rows (we'll store in one buffer nonetheless)
+	// Calculate the number of theoretical rows (we'll store in one buffer nonetheless)
 	size := uint64(len(cache))
 	rows := int(size) / hashBytes
 
@@ -187,7 +187,7 @@ func fnvHash(mix []uint32, data []uint32) {
 // generateDatasetItem combines data from 256 pseudorandomly selected cache nodes,
 // and hashes that to compute a single dataset node.
 func generateDatasetItem(cache []uint32, index uint32, keccak512 hasher) []byte {
-	// Calculate the number of thoretical rows (we use one buffer nonetheless)
+	// Calculate the number of theoretical rows (we use one buffer nonetheless)
 	rows := uint32(len(cache) / hashWords)
 
 	// Initialize the mix
@@ -287,7 +287,7 @@ func generateDataset(dest []uint32, epoch uint64, cache []uint32) {
 // hashimoto aggregates data from the full dataset in order to produce our final
 // value for a particular header hash and nonce.
 func hashimoto(hash []byte, nonce uint64, size uint64, lookup func(index uint32) []uint32) ([]byte, []byte) {
-	// Calculate the number of thoretical rows (we use one buffer nonetheless)
+	// Calculate the number of theoretical rows (we use one buffer nonetheless)
 	rows := uint32(size / mixBytes)
 
 	// Combine header+nonce into a 64 byte seed
diff --git a/consensus/ethash/algorithm_go1.8.go b/consensus/ethash/algorithm_go1.8.go
index 62bf4dec1..d691b758f 100644
--- a/consensus/ethash/algorithm_go1.8.go
+++ b/consensus/ethash/algorithm_go1.8.go
@@ -31,7 +31,7 @@ func cacheSize(block uint64) uint64 {
 		return cacheSizes[epoch]
 	}
 	// No known cache size, calculate manually (sanity branch only)
-	size := uint64(cacheInitBytes + cacheGrowthBytes*uint64(epoch) - hashBytes)
+	size := cacheInitBytes + cacheGrowthBytes*uint64(epoch) - hashBytes
 	for !new(big.Int).SetUint64(size / hashBytes).ProbablyPrime(1) { // Always accurate for n < 2^64
 		size -= 2 * hashBytes
 	}
@@ -49,7 +49,7 @@ func datasetSize(block uint64) uint64 {
 		return datasetSizes[epoch]
 	}
 	// No known dataset size, calculate manually (sanity branch only)
-	size := uint64(datasetInitBytes + datasetGrowthBytes*uint64(epoch) - mixBytes)
+	size := datasetInitBytes + datasetGrowthBytes*uint64(epoch) - mixBytes
 	for !new(big.Int).SetUint64(size / mixBytes).ProbablyPrime(1) { // Always accurate for n < 2^64
 		size -= 2 * mixBytes
 	}
diff --git a/consensus/ethash/algorithm_test.go b/consensus/ethash/algorithm_test.go
index 7e4307a74..7765ff9fe 100644
--- a/consensus/ethash/algorithm_test.go
+++ b/consensus/ethash/algorithm_test.go
@@ -703,8 +703,7 @@ func TestConcurrentDiskCacheGeneration(t *testing.T) {
 
 		go func(idx int) {
 			defer pend.Done()
-
-			ethash := New(cachedir, 0, 1, "", 0, 0)
+			ethash := New(Config{cachedir, 0, 1, "", 0, 0, ModeNormal})
 			if err := ethash.VerifySeal(nil, block.Header()); err != nil {
 				t.Errorf("proc %d: block verification failed: %v", idx, err)
 			}
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index 6a19d449f..2bdb18677 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -36,9 +36,10 @@ import (
 
 // Ethash proof-of-work protocol constants.
 var (
-	frontierBlockReward  *big.Int = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
-	byzantiumBlockReward *big.Int = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Byzantium
-	maxUncles                     = 2                 // Maximum number of uncles allowed in a single block
+	FrontierBlockReward    *big.Int = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
+	ByzantiumBlockReward   *big.Int = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Byzantium
+	maxUncles                       = 2                 // Maximum number of uncles allowed in a single block
+	allowedFutureBlockTime          = 15 * time.Second  // Max time from current time allowed for blocks, before they're considered future blocks
 )
 
 // Various error messages to mark blocks invalid. These should be private to
@@ -68,7 +69,7 @@ func (ethash *Ethash) Author(header *types.Header) (common.Address, error) {
 // stock Ethereum ethash engine.
 func (ethash *Ethash) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error {
 	// If we're running a full engine faking, accept any input as valid
-	if ethash.fakeFull {
+	if ethash.config.PowMode == ModeFullFake {
 		return nil
 	}
 	// Short circuit if the header is known, or it's parent not
@@ -89,7 +90,7 @@ func (ethash *Ethash) VerifyHeader(chain consensus.ChainReader, header *types.He
 // a results channel to retrieve the async verifications.
 func (ethash *Ethash) VerifyHeaders(chain consensus.ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) {
 	// If we're running a full engine faking, accept any input as valid
-	if ethash.fakeFull || len(headers) == 0 {
+	if ethash.config.PowMode == ModeFullFake || len(headers) == 0 {
 		abort, results := make(chan struct{}), make(chan error, len(headers))
 		for i := 0; i < len(headers); i++ {
 			results <- nil
@@ -169,7 +170,7 @@ func (ethash *Ethash) verifyHeaderWorker(chain consensus.ChainReader, headers []
 // rules of the stock Ethereum ethash engine.
 func (ethash *Ethash) VerifyUncles(chain consensus.ChainReader, block *types.Block) error {
 	// If we're running a full engine faking, accept any input as valid
-	if ethash.fakeFull {
+	if ethash.config.PowMode == ModeFullFake {
 		return nil
 	}
 	// Verify that there are at most 2 uncles included in this block
@@ -231,7 +232,7 @@ func (ethash *Ethash) verifyHeader(chain consensus.ChainReader, header, parent *
 			return errLargeBlockTime
 		}
 	} else {
-		if header.Time.Cmp(big.NewInt(time.Now().Unix())) > 0 {
+		if header.Time.Cmp(big.NewInt(time.Now().Add(allowedFutureBlockTime).Unix())) > 0 {
 			return consensus.ErrFutureBlock
 		}
 	}
@@ -455,7 +456,7 @@ func calcDifficultyFrontier(time uint64, parent *types.Header) *big.Int {
 // the PoW difficulty requirements.
 func (ethash *Ethash) VerifySeal(chain consensus.ChainReader, header *types.Header) error {
 	// If we're running a fake PoW, accept any seal as valid
-	if ethash.fakeMode {
+	if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake {
 		time.Sleep(ethash.fakeDelay)
 		if ethash.fakeFail == header.Number.Uint64() {
 			return errInvalidPoW
@@ -480,7 +481,7 @@ func (ethash *Ethash) VerifySeal(chain consensus.ChainReader, header *types.Head
 	cache := ethash.cache(number)
 
 	size := datasetSize(number)
-	if ethash.tester {
+	if ethash.config.PowMode == ModeTest {
 		size = 32 * 1024
 	}
 	digest, result := hashimotoLight(size, cache, header.HashNoNonce().Bytes(), header.Nonce.Uint64())
@@ -529,9 +530,9 @@ var (
 // TODO (karalabe): Move the chain maker into this package and make this private!
 func AccumulateRewards(config *params.ChainConfig, state *state.StateDB, header *types.Header, uncles []*types.Header) {
 	// Select the correct block reward based on chain progression
-	blockReward := frontierBlockReward
+	blockReward := FrontierBlockReward
 	if config.IsByzantium(header.Number) {
-		blockReward = byzantiumBlockReward
+		blockReward = ByzantiumBlockReward
 	}
 	// Accumulate the rewards for the miner and any included uncles
 	reward := new(big.Int).Set(blockReward)
diff --git a/consensus/ethash/ethash.go b/consensus/ethash/ethash.go
index dd6147072..a78b3a895 100644
--- a/consensus/ethash/ethash.go
+++ b/consensus/ethash/ethash.go
@@ -45,7 +45,7 @@ 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 = New("", 3, 0, "", 1, 0)
+	sharedEthash = New(Config{"", 3, 0, "", 1, 0, ModeNormal})
 
 	// algorithmRevision is the data structure version used for file naming.
 	algorithmRevision = 23
@@ -320,15 +320,32 @@ func MakeDataset(block uint64, dir string) {
 	d.release()
 }
 
+// Mode defines the type and amount of PoW verification an ethash engine makes.
+type Mode uint
+
+const (
+	ModeNormal Mode = iota
+	ModeShared
+	ModeTest
+	ModeFake
+	ModeFullFake
+)
+
+// Config are the configuration parameters of the ethash.
+type Config struct {
+	CacheDir       string
+	CachesInMem    int
+	CachesOnDisk   int
+	DatasetDir     string
+	DatasetsInMem  int
+	DatasetsOnDisk int
+	PowMode        Mode
+}
+
 // Ethash is a consensus engine based on proot-of-work 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
+	config Config
 
 	caches   map[uint64]*cache   // In memory caches to avoid regenerating too often
 	fcache   *cache              // Pre-generated cache for the estimated future epoch
@@ -342,10 +359,7 @@ type Ethash struct {
 	hashrate metrics.Meter // Meter tracking the average hashrate
 
 	// The fields below are hooks for testing
-	tester    bool          // Flag whether to use a smaller test dataset
 	shared    *Ethash       // Shared PoW verifier to avoid cache regeneration
-	fakeMode  bool          // Flag whether to disable PoW checking
-	fakeFull  bool          // Flag whether to disable all consensus rules
 	fakeFail  uint64        // Block number which fails PoW check even in fake mode
 	fakeDelay time.Duration // Time delay to sleep for before returning from verify
 
@@ -353,28 +367,23 @@ type Ethash struct {
 }
 
 // New creates a full sized ethash PoW scheme.
-func New(cachedir string, cachesinmem, cachesondisk int, dagdir string, dagsinmem, dagsondisk int) *Ethash {
-	if cachesinmem <= 0 {
-		log.Warn("One ethash cache must always be in memory", "requested", cachesinmem)
-		cachesinmem = 1
+func New(config Config) *Ethash {
+	if config.CachesInMem <= 0 {
+		log.Warn("One ethash cache must always be in memory", "requested", config.CachesInMem)
+		config.CachesInMem = 1
 	}
-	if cachedir != "" && cachesondisk > 0 {
-		log.Info("Disk storage enabled for ethash caches", "dir", cachedir, "count", cachesondisk)
+	if config.CacheDir != "" && config.CachesOnDisk > 0 {
+		log.Info("Disk storage enabled for ethash caches", "dir", config.CacheDir, "count", config.CachesOnDisk)
 	}
-	if dagdir != "" && dagsondisk > 0 {
-		log.Info("Disk storage enabled for ethash DAGs", "dir", dagdir, "count", dagsondisk)
+	if config.DatasetDir != "" && config.DatasetsOnDisk > 0 {
+		log.Info("Disk storage enabled for ethash DAGs", "dir", config.DatasetDir, "count", config.DatasetsOnDisk)
 	}
 	return &Ethash{
-		cachedir:     cachedir,
-		cachesinmem:  cachesinmem,
-		cachesondisk: cachesondisk,
-		dagdir:       dagdir,
-		dagsinmem:    dagsinmem,
-		dagsondisk:   dagsondisk,
-		caches:       make(map[uint64]*cache),
-		datasets:     make(map[uint64]*dataset),
-		update:       make(chan struct{}),
-		hashrate:     metrics.NewMeter(),
+		config:   config,
+		caches:   make(map[uint64]*cache),
+		datasets: make(map[uint64]*dataset),
+		update:   make(chan struct{}),
+		hashrate: metrics.NewMeter(),
 	}
 }
 
@@ -382,12 +391,14 @@ func New(cachedir string, cachesinmem, cachesondisk int, dagdir string, dagsinme
 // purposes.
 func NewTester() *Ethash {
 	return &Ethash{
-		cachesinmem: 1,
-		caches:      make(map[uint64]*cache),
-		datasets:    make(map[uint64]*dataset),
-		tester:      true,
-		update:      make(chan struct{}),
-		hashrate:    metrics.NewMeter(),
+		config: Config{
+			CachesInMem: 1,
+			PowMode:     ModeTest,
+		},
+		caches:   make(map[uint64]*cache),
+		datasets: make(map[uint64]*dataset),
+		update:   make(chan struct{}),
+		hashrate: metrics.NewMeter(),
 	}
 }
 
@@ -395,27 +406,45 @@ func NewTester() *Ethash {
 // all blocks' seal as valid, though they still have to conform to the Ethereum
 // consensus rules.
 func NewFaker() *Ethash {
-	return &Ethash{fakeMode: true}
+	return &Ethash{
+		config: Config{
+			PowMode: ModeFake,
+		},
+	}
 }
 
 // NewFakeFailer creates a ethash consensus engine with a fake PoW scheme that
 // accepts all blocks as valid apart from the single one specified, though they
 // still have to conform to the Ethereum consensus rules.
 func NewFakeFailer(fail uint64) *Ethash {
-	return &Ethash{fakeMode: true, fakeFail: fail}
+	return &Ethash{
+		config: Config{
+			PowMode: ModeFake,
+		},
+		fakeFail: fail,
+	}
 }
 
 // NewFakeDelayer creates a ethash consensus engine with a fake PoW scheme that
 // accepts all blocks as valid, but delays verifications by some time, though
 // they still have to conform to the Ethereum consensus rules.
 func NewFakeDelayer(delay time.Duration) *Ethash {
-	return &Ethash{fakeMode: true, fakeDelay: delay}
+	return &Ethash{
+		config: Config{
+			PowMode: ModeFake,
+		},
+		fakeDelay: delay,
+	}
 }
 
 // NewFullFaker creates an ethash consensus engine with a full fake scheme that
 // accepts all blocks as valid, without checking any consensus rules whatsoever.
 func NewFullFaker() *Ethash {
-	return &Ethash{fakeMode: true, fakeFull: true}
+	return &Ethash{
+		config: Config{
+			PowMode: ModeFullFake,
+		},
+	}
 }
 
 // NewShared creates a full sized ethash PoW shared between all requesters running
@@ -436,7 +465,7 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 	current, future := ethash.caches[epoch], (*cache)(nil)
 	if current == nil {
 		// No in-memory cache, evict the oldest if the cache limit was reached
-		for len(ethash.caches) > 0 && len(ethash.caches) >= ethash.cachesinmem {
+		for len(ethash.caches) > 0 && len(ethash.caches) >= ethash.config.CachesInMem {
 			var evict *cache
 			for _, cache := range ethash.caches {
 				if evict == nil || evict.used.After(cache.used) {
@@ -473,7 +502,7 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 	ethash.lock.Unlock()
 
 	// Wait for generation finish, bump the timestamp and finalize the cache
-	current.generate(ethash.cachedir, ethash.cachesondisk, ethash.tester)
+	current.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.PowMode == ModeTest)
 
 	current.lock.Lock()
 	current.used = time.Now()
@@ -481,7 +510,7 @@ func (ethash *Ethash) cache(block uint64) []uint32 {
 
 	// 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)
+		go future.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.PowMode == ModeTest)
 	}
 	return current.cache
 }
@@ -498,7 +527,7 @@ func (ethash *Ethash) dataset(block uint64) []uint32 {
 	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) > 0 && len(ethash.datasets) >= ethash.dagsinmem {
+		for len(ethash.datasets) > 0 && len(ethash.datasets) >= ethash.config.DatasetsInMem {
 			var evict *dataset
 			for _, dataset := range ethash.datasets {
 				if evict == nil || evict.used.After(dataset.used) {
@@ -536,7 +565,7 @@ func (ethash *Ethash) dataset(block uint64) []uint32 {
 	ethash.lock.Unlock()
 
 	// Wait for generation finish, bump the timestamp and finalize the cache
-	current.generate(ethash.dagdir, ethash.dagsondisk, ethash.tester)
+	current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
 
 	current.lock.Lock()
 	current.used = time.Now()
@@ -544,7 +573,7 @@ func (ethash *Ethash) dataset(block uint64) []uint32 {
 
 	// 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)
+		go future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
 	}
 	return current.dataset
 }
diff --git a/consensus/ethash/sealer.go b/consensus/ethash/sealer.go
index 784e8f649..c2447e473 100644
--- a/consensus/ethash/sealer.go
+++ b/consensus/ethash/sealer.go
@@ -34,7 +34,7 @@ import (
 // the block's difficulty requirements.
 func (ethash *Ethash) Seal(chain consensus.ChainReader, block *types.Block, stop <-chan struct{}) (*types.Block, error) {
 	// If we're running a fake PoW, simply return a 0 nonce immediately
-	if ethash.fakeMode {
+	if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake {
 		header := block.Header()
 		header.Nonce, header.MixDigest = types.BlockNonce{}, common.Hash{}
 		return block.WithSeal(header), nil