Merge pull request #2301 from obscuren/uncle-fix

core: announce ChainSideEvent during reorg

core/blockchain.go

@@ -1269,11 +1269,13 @@ func (self *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 	var (
 		newChain          types.Blocks
+		oldChain          types.Blocks
 		commonBlock       *types.Block
 		oldStart          = oldBlock
 		newStart          = newBlock
 		deletedTxs        types.Transactions
 		deletedLogs       vm.Logs
+		deletedLogsByHash = make(map[common.Hash]vm.Logs)
 		// collectLogs collects the logs that were generated during the
 		// processing of the block that corresponds with the given hash.
 		// These logs are later announced as deleted.
@@ -1282,6 +1284,8 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 			receipts := GetBlockReceipts(self.chainDb, h)
 			for _, receipt := range receipts {
 				deletedLogs = append(deletedLogs, receipt.Logs...)
+
+				deletedLogsByHash[h] = receipt.Logs
 			}
 		}
 	)
@@ -1290,6 +1294,7 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 	if oldBlock.NumberU64() > newBlock.NumberU64() {
 		// reduce old chain
 		for oldBlock = oldBlock; oldBlock != nil && oldBlock.NumberU64() != newBlock.NumberU64(); oldBlock = self.GetBlock(oldBlock.ParentHash()) {
+			oldChain = append(oldChain, oldBlock)
 			deletedTxs = append(deletedTxs, oldBlock.Transactions()...)
 
 			collectLogs(oldBlock.Hash())
@@ -1313,6 +1318,8 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 			commonBlock = oldBlock
 			break
 		}
+
+		oldChain = append(oldChain, oldBlock)
 		newChain = append(newChain, newBlock)
 		deletedTxs = append(deletedTxs, oldBlock.Transactions()...)
 		collectLogs(oldBlock.Hash())
@@ -1369,6 +1376,14 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 		go self.eventMux.Post(RemovedLogsEvent{deletedLogs})
 	}
 
+	if len(oldChain) > 0 {
+		go func() {
+			for _, block := range oldChain {
+				self.eventMux.Post(ChainSideEvent{Block: block, Logs: deletedLogsByHash[block.Hash()]})
+			}
+		}()
+	}
+
 	return nil
 }
 

core/blockchain_test.go

@@ -25,6 +25,7 @@ import (
 	"runtime"
 	"strconv"
 	"testing"
+	"time"
 
 	"github.com/ethereum/ethash"
 	"github.com/ethereum/go-ethereum/common"
@@ -1006,3 +1007,82 @@ func TestLogReorgs(t *testing.T) {
 		t.Error("expected logs")
 	}
 }
+
+func TestReorgSideEvent(t *testing.T) {
+	var (
+		db, _   = ethdb.NewMemDatabase()
+		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
+		genesis = WriteGenesisBlockForTesting(db, GenesisAccount{addr1, big.NewInt(10000000000000)})
+	)
+
+	evmux := &event.TypeMux{}
+	blockchain, _ := NewBlockChain(db, FakePow{}, evmux)
+
+	chain, _ := GenerateChain(genesis, db, 3, func(i int, gen *BlockGen) {
+		if i == 2 {
+			gen.OffsetTime(9)
+		}
+	})
+	if _, err := blockchain.InsertChain(chain); err != nil {
+		t.Fatalf("failed to insert chain: %v", err)
+	}
+
+	replacementBlocks, _ := GenerateChain(genesis, db, 4, func(i int, gen *BlockGen) {
+		tx, err := types.NewContractCreation(gen.TxNonce(addr1), new(big.Int), big.NewInt(1000000), new(big.Int), nil).SignECDSA(key1)
+		if err != nil {
+			t.Fatalf("failed to create tx: %v", err)
+		}
+		gen.AddTx(tx)
+	})
+
+	subs := evmux.Subscribe(ChainSideEvent{})
+	if _, err := blockchain.InsertChain(replacementBlocks); err != nil {
+		t.Fatalf("failed to insert chain: %v", err)
+	}
+
+	// first two block of the secondary chain are for a brief moment considered
+	// side chains because up to that point the first one is considered the
+	// heavier chain.
+	expectedSideHashes := map[common.Hash]bool{
+		replacementBlocks[0].Hash(): true,
+		replacementBlocks[1].Hash(): true,
+		chain[0].Hash():             true,
+		chain[1].Hash():             true,
+		chain[2].Hash():             true,
+	}
+
+	i := 0
+
+	const timeoutDura = 10 * time.Second
+	timeout := time.NewTimer(timeoutDura)
+done:
+	for {
+		select {
+		case ev := <-subs.Chan():
+			block := ev.Data.(ChainSideEvent).Block
+			if _, ok := expectedSideHashes[block.Hash()]; !ok {
+				t.Errorf("%d: didn't expect %x to be in side chain", i, block.Hash())
+			}
+			i++
+
+			if i == len(expectedSideHashes) {
+				timeout.Stop()
+
+				break done
+			}
+			timeout.Reset(timeoutDura)
+
+		case <-timeout.C:
+			t.Fatal("Timeout. Possibly not all blocks were triggered for sideevent")
+		}
+	}
+
+	// make sure no more events are fired
+	select {
+	case e := <-subs.Chan():
+		t.Errorf("unexectped event fired: %v", e)
+	case <-time.After(250 * time.Millisecond):
+	}
+
+}