Merge pull request ethereum#299 from nextyio/prioritized

Prioritize block with random seed by double the normal block weight

consensus/dccs/2_dccs.go

@@ -59,6 +59,7 @@ var (
 	errInvalidExtendedData       = errors.New("Extended data does not matches")
 	errInvalidRandomData         = errors.New("Invalid random data in extra data")
 	errInvalidRandomDataSize     = errors.New("Invalid random data size from relayer")
+	errInvalidPrioritiezedDiff   = errors.New("Invalid prioritized block difficulty")
 
 	errInvalidPriceData  = errors.New("price block contains invalid price value")
 	errUnexpectPriceData = errors.New("non-price block contains price value")
@@ -162,8 +163,8 @@ func (c *Context) verifyCascadingFields2() error {
 	}
 
 	// Ensure that the block's timestamp isn't too close to it's parent
-	parent := c.getHeaderByHash(header.ParentHash)
-	if parent == nil || parent.Number.Uint64() != number-1 || parent.Hash() != header.ParentHash {
+	parent := c.getHeader(header.ParentHash, number-1)
+	if parent == nil {
 		return consensus.ErrUnknownAncestor
 	}
 	if parent.Time+c.engine.config.Period > header.Time {
@@ -269,8 +270,11 @@ func (c *Context) verifySeal2() error {
 		return errRecentlySigned
 	}
 
+	// block with random seed or the CoLoa hardfork block
+	prioritized := header.Nonce == types.BlockNonce{}
+
 	// Ensure that the difficulty corresponds to the turn-ness of the signer
-	signerDifficulty := queue.difficulty(signer, c.getHeaderByHash, c.engine.signatures)
+	signerDifficulty := queue.difficulty(signer, prioritized, c.getHeaderByHash, c.engine.signatures)
 	if header.Difficulty.Uint64() != signerDifficulty {
 		return errInvalidDifficulty
 	}
@@ -465,10 +469,6 @@ func (c *Context) prepare2(header *types.Header) error {
 		return err
 	}
 
-	// Set the correct difficulty
-	difficulty := queue.difficulty(c.engine.signer, c.chain.GetHeaderByHash, c.engine.signatures)
-	header.Difficulty = new(big.Int).SetUint64(difficulty)
-
 	// Ensure the timestamp has the correct delay
 	header.Time = parent.Time + c.engine.config.Period
 	if header.Time < uint64(time.Now().Unix()) {
@@ -503,6 +503,13 @@ func (c *Context) prepare2(header *types.Header) error {
 		header.Nonce = c.getBlockNonce(parent)
 	}
 
+	// block with random seed or the CoLoa hardfork block
+	prioritized := header.Nonce == types.BlockNonce{}
+
+	// Set the correct difficulty
+	difficulty := queue.difficulty(c.engine.signer, prioritized, c.chain.GetHeaderByHash, c.engine.signatures)
+	header.Difficulty = new(big.Int).SetUint64(difficulty)
+
 	var price *Price
 	if c.engine.config.IsPriceBlock(number) {
 		price = c.engine.PriceEngine().CurrentPrice()

consensus/dccs/2_queue.go

@@ -192,7 +192,7 @@ func (q *SealingQueue) offset(signer common.Address,
 	return offset, nil
 }
 
-func (q *SealingQueue) difficulty(address common.Address,
+func (q *SealingQueue) difficulty(address common.Address, prioritized bool,
 	getHeaderByHash func(common.Hash) *types.Header,
 	sigCache *lru.ARCCache) uint64 {
 
@@ -201,9 +201,13 @@ func (q *SealingQueue) difficulty(address common.Address,
 		return 0
 	}
 
-	n := len(q.active)
+	diff := uint64(len(q.active) - offset)
 
-	return uint64(n - offset)
+	if prioritized {
+		diff <<= 1
+	}
+
+	return diff
 }
 
 // recents len is MIN(lastActiveLen,activeLen)/2
@@ -289,8 +293,17 @@ func (c *Context) getSealingQueue(parentHash common.Hash) (*SealingQueue, error)
 		addActive(sealer)
 
 		// use the difficulty for total number of recently active sealer count
-		if header.Difficulty.Uint64() > maxDiff {
-			maxDiff = header.Difficulty.Uint64()
+		diff := header.Difficulty.Uint64()
+		if header.Nonce == (types.BlockNonce{}) {
+			if diff&0x01 != 0 {
+				// prioritized difficulty cannot be odd number
+				return nil, errInvalidPrioritiezedDiff
+			}
+			// correct difficulty for prioritized block
+			diff >>= 1
+		}
+		if diff > maxDiff {
+			maxDiff = diff
 		}
 		// somewhat probabilistically optimized, fairly safe nonetheless
 		if i < minBlockToScan || len(recents) < int(maxDiff)/2 {

ethstats/ethstats.go

@@ -476,6 +476,7 @@ type blockStats struct {
 	Miner      common.Address `json:"miner"`
 	GasUsed    uint64         `json:"gasUsed"`
 	GasLimit   uint64         `json:"gasLimit"`
+	Nonce      uint64         `json:"nonce"`
 	Diff       string         `json:"difficulty"`
 	TotalDiff  string         `json:"totalDifficulty"`
 	Txs        []txStats      `json:"transactions"`
@@ -593,6 +594,7 @@ func (s *Service) assembleBlockStats(block *types.Block) *blockStats {
 		Miner:      author,
 		GasUsed:    header.GasUsed,
 		GasLimit:   header.GasLimit,
+		Nonce:      header.Nonce.Uint64(),
 		Diff:       header.Difficulty.String(),
 		TotalDiff:  td.String(),
 		Txs:        txs,