core: during chain reorg rewrite receipts and transactions

Added PutBlockReceipts; storing receipts by blocks. Eventually this will
require pruning during some cleanup cycle. During forks the receipts by
block are used to get the new canonical receipts and transactions.

This PR fixes #1473 by rewriting transactions and receipts from the point
of where the fork occured.

3 files changed, 46 insertions, 13 deletions

diff --git a/core/block_processor.go b/core/block_processor.go
index f50ebb55a..e24b290dd 100644
--- a/core/block_processor.go
+++ b/core/block_processor.go
@@ -342,7 +342,7 @@ func (sm *BlockProcessor) VerifyUncles(statedb *state.StateDB, block, parent *ty
 // GetBlockReceipts returns the receipts beloniging to the block hash
 func (sm *BlockProcessor) GetBlockReceipts(bhash common.Hash) types.Receipts {
 	if block := sm.ChainManager().GetBlock(bhash); block != nil {
-		return GetReceiptsFromBlock(sm.extraDb, block)
+		return GetBlockReceipts(sm.extraDb, block.Hash())
 	}
 
 	return nil
@@ -352,7 +352,7 @@ func (sm *BlockProcessor) GetBlockReceipts(bhash common.Hash) types.Receipts {
 // where it tries to get it from the (updated) method which gets them from the receipts or
 // the depricated way by re-processing the block.
 func (sm *BlockProcessor) GetLogs(block *types.Block) (logs state.Logs, err error) {
-	receipts := GetReceiptsFromBlock(sm.extraDb, block)
+	receipts := GetBlockReceipts(sm.extraDb, block.Hash())
 	if len(receipts) > 0 {
 		// coalesce logs
 		for _, receipt := range receipts {
diff --git a/core/chain_manager.go b/core/chain_manager.go
index 8fa13ddec..1a703d084 100644
--- a/core/chain_manager.go
+++ b/core/chain_manager.go
@@ -667,6 +667,8 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
 			queue[i] = ChainSplitEvent{block, logs}
 			queueEvent.splitCount++
 		}
+		PutBlockReceipts(self.extraDb, block, receipts)
+
 		stats.processed++
 	}
 
@@ -744,7 +746,12 @@ func (self *ChainManager) merge(oldBlock, newBlock *types.Block) error {
 	// insert blocks. Order does not matter. Last block will be written in ImportChain itself which creates the new head properly
 	self.mu.Lock()
 	for _, block := range newChain {
+		// insert the block in the canonical way, re-writing history
 		self.insert(block)
+		// write canonical receipts and transactions
+		PutTransactions(self.extraDb, block, block.Transactions())
+		PutReceipts(self.extraDb, GetBlockReceipts(self.extraDb, block.Hash()))
+
 	}
 	self.mu.Unlock()
 
diff --git a/core/transaction_util.go b/core/transaction_util.go
index 0efeddfde..752d4f088 100644
--- a/core/transaction_util.go
+++ b/core/transaction_util.go
@@ -24,7 +24,10 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
-var receiptsPre = []byte("receipts-")
+var (
+	receiptsPre      = []byte("receipts-")
+	blockReceiptsPre = []byte("receipts-block-")
+)
 
 // PutTransactions stores the transactions in the given database
 func PutTransactions(db common.Database, block *types.Block, txs types.Transactions) {
@@ -85,17 +88,40 @@ func GetReceipt(db common.Database, txHash common.Hash) *types.Receipt {
 	return &receipt
 }
 
-// GetReceiptFromBlock returns all receipts with the given block
-func GetReceiptsFromBlock(db common.Database, block *types.Block) types.Receipts {
-	// at some point we want:
-	//receipts := make(types.Receipts, len(block.Transactions()))
-	// but since we need to support legacy, we can't (yet)
-	var receipts types.Receipts
-	for _, tx := range block.Transactions() {
-		if receipt := GetReceipt(db, tx.Hash()); receipt != nil {
-			receipts = append(receipts, receipt)
-		}
+// GetBlockReceipts returns the receipts generated by the transactions
+// included in block's given hash.
+func GetBlockReceipts(db common.Database, hash common.Hash) types.Receipts {
+	data, _ := db.Get(append(blockReceiptsPre, hash[:]...))
+	if len(data) == 0 {
+		return nil
 	}
 
+	var receipts types.Receipts
+	err := rlp.DecodeBytes(data, &receipts)
+	if err != nil {
+		glog.V(logger.Core).Infoln("GetReceiptse err", err)
+	}
 	return receipts
 }
+
+// PutBlockReceipts stores the block's transactions associated receipts
+// and stores them by block hash in a single slice. This is required for
+// forks and chain reorgs
+func PutBlockReceipts(db common.Database, block *types.Block, receipts types.Receipts) error {
+	rs := make([]*types.ReceiptForStorage, len(receipts))
+	for i, receipt := range receipts {
+		rs[i] = (*types.ReceiptForStorage)(receipt)
+	}
+	bytes, err := rlp.EncodeToBytes(rs)
+	if err != nil {
+		return err
+	}
+
+	hash := block.Hash()
+	err = db.Put(append(blockReceiptsPre, hash[:]...), bytes)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}