Merge pull request #2024 from obscuren/exp-logs

core: added a new RemovedLogEvent

core/blockchain.go

@@ -1240,6 +1240,17 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 		oldStart    = oldBlock
 		newStart    = newBlock
 		deletedTxs  types.Transactions
+		deletedLogs 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.
+		collectLogs = func(h common.Hash) {
+			// Coalesce logs
+			receipts := GetBlockReceipts(self.chainDb, h)
+			for _, receipt := range receipts {
+				deletedLogs = append(deletedLogs, receipt.Logs...)
+			}
+		}
 	)
 
 	// first reduce whoever is higher bound
@@ -1247,6 +1258,8 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 		// reduce old chain
 		for oldBlock = oldBlock; oldBlock != nil && oldBlock.NumberU64() != newBlock.NumberU64(); oldBlock = self.GetBlock(oldBlock.ParentHash()) {
 			deletedTxs = append(deletedTxs, oldBlock.Transactions()...)
+
+			collectLogs(oldBlock.Hash())
 		}
 	} else {
 		// reduce new chain and append new chain blocks for inserting later on
@@ -1269,6 +1282,7 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 		}
 		newChain = append(newChain, newBlock)
 		deletedTxs = append(deletedTxs, oldBlock.Transactions()...)
+		collectLogs(oldBlock.Hash())
 
 		oldBlock, newBlock = self.GetBlock(oldBlock.ParentHash()), self.GetBlock(newBlock.ParentHash())
 		if oldBlock == nil {
@@ -1302,7 +1316,6 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 		if err := WriteMipmapBloom(self.chainDb, block.NumberU64(), receipts); err != nil {
 			return err
 		}
-
 		addedTxs = append(addedTxs, block.Transactions()...)
 	}
 
@@ -1316,7 +1329,12 @@ func (self *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 	}
 	// Must be posted in a goroutine because of the transaction pool trying
 	// to acquire the chain manager lock
+	if len(diff) > 0 {
 		go self.eventMux.Post(RemovedTransactionEvent{diff})
+	}
+	if len(deletedLogs) > 0 {
+		go self.eventMux.Post(RemovedLogEvent{deletedLogs})
+	}
 
 	return nil
 }

core/blockchain_test.go

@@ -963,3 +963,46 @@ func TestChainTxReorgs(t *testing.T) {
 		}
 	}
 }
+
+func TestLogReorgs(t *testing.T) {
+	params.MinGasLimit = big.NewInt(125000)      // Minimum the gas limit may ever be.
+	params.GenesisGasLimit = big.NewInt(3141592) // Gas limit of the Genesis block.
+
+	var (
+		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
+		db, _   = ethdb.NewMemDatabase()
+		// this code generates a log
+		code = common.Hex2Bytes("60606040525b7f24ec1d3ff24c2f6ff210738839dbc339cd45a5294d85c79361016243157aae7b60405180905060405180910390a15b600a8060416000396000f360606040526008565b00")
+	)
+	genesis := WriteGenesisBlockForTesting(db,
+		GenesisAccount{addr1, big.NewInt(10000000000000)},
+	)
+
+	evmux := &event.TypeMux{}
+	blockchain, _ := NewBlockChain(db, FakePow{}, evmux)
+
+	subs := evmux.Subscribe(RemovedLogEvent{})
+	chain, _ := GenerateChain(genesis, db, 2, func(i int, gen *BlockGen) {
+		if i == 1 {
+			tx, err := types.NewContractCreation(gen.TxNonce(addr1), new(big.Int), big.NewInt(1000000), new(big.Int), code).SignECDSA(key1)
+			if err != nil {
+				t.Fatalf("failed to create tx: %v", err)
+			}
+			gen.AddTx(tx)
+		}
+	})
+	if _, err := blockchain.InsertChain(chain); err != nil {
+		t.Fatalf("failed to insert chain: %v", err)
+	}
+
+	chain, _ = GenerateChain(genesis, db, 3, func(i int, gen *BlockGen) {})
+	if _, err := blockchain.InsertChain(chain); err != nil {
+		t.Fatalf("failed to insert forked chain: %v", err)
+	}
+
+	ev := <-subs.Chan()
+	if len(ev.Data.(RemovedLogEvent).Logs) == 0 {
+		t.Error("expected logs")
+	}
+}

core/chain_makers.go

@@ -90,6 +90,7 @@ func (b *BlockGen) AddTx(tx *types.Transaction) {
 	if b.gasPool == nil {
 		b.SetCoinbase(common.Address{})
 	}
+	b.statedb.StartRecord(tx.Hash(), common.Hash{}, len(b.txs))
 	_, gas, err := ApplyMessage(NewEnv(b.statedb, nil, tx, b.header), tx, b.gasPool)
 	if err != nil {
 		panic(err)
@@ -97,8 +98,7 @@ func (b *BlockGen) AddTx(tx *types.Transaction) {
 	root := b.statedb.IntermediateRoot()
 	b.header.GasUsed.Add(b.header.GasUsed, gas)
 	receipt := types.NewReceipt(root.Bytes(), b.header.GasUsed)
-	logs := b.statedb.GetLogs(tx.Hash())
-	receipt.Logs = logs
+	receipt.Logs = b.statedb.GetLogs(tx.Hash())
 	receipt.Bloom = types.CreateBloom(types.Receipts{receipt})
 	b.txs = append(b.txs, tx)
 	b.receipts = append(b.receipts, receipt)

core/events.go

@@ -39,6 +39,9 @@ type NewMinedBlockEvent struct{ Block *types.Block }
 // RemovedTransactionEvent is posted when a reorg happens
 type RemovedTransactionEvent struct{ Txs types.Transactions }
 
+// RemovedLogEvent is posted when a reorg happens
+type RemovedLogEvent struct{ Logs vm.Logs }
+
 // ChainSplit is posted when a new head is detected
 type ChainSplitEvent struct {
 	Block *types.Block