core, dex, internal: block proposer syncing (first iteration) (#96)

* dex, internal: block proposer syncing (first iteration)

* core: find block from db if not in memory

This fix handles stopping proposing and then restarting

* core: no need to reorg when reset

Dexon will not fork. This commit also fix when a block confirm but
its parent is not in db yet, during restarting proposing.

* dex: always accept NewBlockMsg, NewBlockHashesMsg

We need to accept NewBlockMsg, NewBlockHashesMsg to sync current block with
other peers in block proposer mode when syncing lattice data. It's a waste
when the node is synced and start proposing.

Todo: control msg processing on/off more granular, accept NewBlockMsg,
NewBlockHashesMsg when syncing, but stop when synced.

2 files changed, 2 insertions, 57 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index 31336f555..8ceb1186c 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -1796,8 +1796,6 @@ func (bc *BlockChain) processPendingBlock(
 		return nil, nil, nil, fmt.Errorf("validate witness data error: %v", err)
 	}
 
-	currentBlock := bc.CurrentBlock()
-
 	var (
 		receipts types.Receipts
 		usedGas  = new(uint64)
@@ -1810,8 +1808,8 @@ func (bc *BlockChain) processPendingBlock(
 	var err error
 	parent, exist := bc.pendingBlocks[block.NumberU64()-1]
 	if !exist {
-		parentBlock = currentBlock
-		if parentBlock.NumberU64() != block.NumberU64()-1 {
+		parentBlock = bc.GetBlockByNumber(block.NumberU64() - 1)
+		if parentBlock == nil {
 			return nil, nil, nil, fmt.Errorf("parent block %d not exist", block.NumberU64()-1)
 		}
 	} else {
diff --git a/core/tx_pool.go b/core/tx_pool.go
index ea2025cde..911b6c261 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -19,7 +19,6 @@ package core
 import (
 	"errors"
 	"fmt"
-	"math"
 	"math/big"
 	"sort"
 	"sync"
@@ -405,53 +404,6 @@ func (pool *TxPool) lockedReset(oldHead, newHead *types.Header) {
 // reset retrieves the current state of the blockchain and ensures the content
 // of the transaction pool is valid with regard to the chain state.
 func (pool *TxPool) reset(oldHead, newHead *types.Header) {
-	// If we're reorging an old state, reinject all dropped transactions
-	var reinject types.Transactions
-
-	if oldHead != nil && oldHead.Hash() != newHead.ParentHash {
-		// If the reorg is too deep, avoid doing it (will happen during fast sync)
-		oldNum := oldHead.Number.Uint64()
-		newNum := newHead.Number.Uint64()
-
-		if depth := uint64(math.Abs(float64(oldNum) - float64(newNum))); depth > 64 {
-			log.Debug("Skipping deep transaction reorg", "depth", depth)
-		} else {
-			// Reorg seems shallow enough to pull in all transactions into memory
-			var discarded, included types.Transactions
-
-			var (
-				rem = pool.chain.GetBlock(oldHead.Hash(), oldHead.Number.Uint64())
-				add = pool.chain.GetBlock(newHead.Hash(), newHead.Number.Uint64())
-			)
-			for rem.NumberU64() > add.NumberU64() {
-				discarded = append(discarded, rem.Transactions()...)
-				if rem = pool.chain.GetBlock(rem.ParentHash(), rem.NumberU64()-1); rem == nil {
-					log.Error("Unrooted old chain seen by tx pool", "block", oldHead.Number, "hash", oldHead.Hash())
-					return
-				}
-			}
-			for add.NumberU64() > rem.NumberU64() {
-				included = append(included, add.Transactions()...)
-				if add = pool.chain.GetBlock(add.ParentHash(), add.NumberU64()-1); add == nil {
-					log.Error("Unrooted new chain seen by tx pool", "block", newHead.Number, "hash", newHead.Hash())
-					return
-				}
-			}
-			for rem.Hash() != add.Hash() {
-				discarded = append(discarded, rem.Transactions()...)
-				if rem = pool.chain.GetBlock(rem.ParentHash(), rem.NumberU64()-1); rem == nil {
-					log.Error("Unrooted old chain seen by tx pool", "block", oldHead.Number, "hash", oldHead.Hash())
-					return
-				}
-				included = append(included, add.Transactions()...)
-				if add = pool.chain.GetBlock(add.ParentHash(), add.NumberU64()-1); add == nil {
-					log.Error("Unrooted new chain seen by tx pool", "block", newHead.Number, "hash", newHead.Hash())
-					return
-				}
-			}
-			reinject = types.TxDifference(discarded, included)
-		}
-	}
 	// Initialize the internal state to the current head
 	if newHead == nil {
 		newHead = pool.chain.CurrentBlock().Header() // Special case during testing
@@ -465,11 +417,6 @@ func (pool *TxPool) reset(oldHead, newHead *types.Header) {
 	pool.pendingState = state.ManageState(statedb)
 	pool.currentMaxGas = newHead.GasLimit
 
-	// Inject any transactions discarded due to reorgs
-	log.Debug("Reinjecting stale transactions", "count", len(reinject))
-	senderCacher.recover(pool.signer, reinject)
-	pool.addTxsLocked(reinject, false)
-
 	// validate the pool of pending transactions, this will remove
 	// any transactions that have been included in the block or
 	// have been invalidated because of another transaction (e.g.