core, eth: add/use separate header/body accessors

core/chain_manager.go

@@ -48,6 +48,8 @@ var (
 )
 
 const (
+	headerCacheLimit    = 256
+	bodyCacheLimit      = 256
 	blockCacheLimit     = 256
 	maxFutureBlocks     = 256
 	maxTimeFutureBlocks = 30
@@ -71,7 +73,10 @@ type ChainManager struct {
 	lastBlockHash   common.Hash
 	currentGasLimit *big.Int
 
-	cache        *lru.Cache // cache is the LRU caching
+	headerCache  *lru.Cache // Cache for the most recent block headers
+	bodyCache    *lru.Cache // Cache for the most recent block bodies
+	bodyRLPCache *lru.Cache // Cache for the most recent block bodies in RLP encoded format
+	blockCache   *lru.Cache // Cache for the most recent entire blocks
 	futureBlocks *lru.Cache // future blocks are blocks added for later processing
 
 	quit    chan struct{}
@@ -84,12 +89,21 @@ type ChainManager struct {
 }
 
 func NewChainManager(chainDb common.Database, pow pow.PoW, mux *event.TypeMux) (*ChainManager, error) {
-	cache, _ := lru.New(blockCacheLimit)
+	headerCache, _ := lru.New(headerCacheLimit)
+	bodyCache, _ := lru.New(bodyCacheLimit)
+	bodyRLPCache, _ := lru.New(bodyCacheLimit)
+	blockCache, _ := lru.New(blockCacheLimit)
+	futureBlocks, _ := lru.New(maxFutureBlocks)
+
 	bc := &ChainManager{
 		chainDb:      chainDb,
 		eventMux:     mux,
 		quit:         make(chan struct{}),
-		cache:    cache,
+		headerCache:  headerCache,
+		bodyCache:    bodyCache,
+		bodyRLPCache: bodyRLPCache,
+		blockCache:   blockCache,
+		futureBlocks: futureBlocks,
 		pow:          pow,
 	}
 
@@ -105,11 +119,9 @@ func NewChainManager(chainDb common.Database, pow pow.PoW, mux *event.TypeMux) (
 		}
 		glog.V(logger.Info).Infoln("WARNING: Wrote default ethereum genesis block")
 	}
-
 	if err := bc.setLastState(); err != nil {
 		return nil, err
 	}
-
 	// Check the current state of the block hashes and make sure that we do not have any of the bad blocks in our chain
 	for hash, _ := range BadHashes {
 		if block := bc.GetBlock(hash); block != nil {
@@ -123,14 +135,8 @@ func NewChainManager(chainDb common.Database, pow pow.PoW, mux *event.TypeMux) (
 			glog.V(logger.Error).Infoln("Chain reorg was successfull. Resuming normal operation")
 		}
 	}
-
 	// Take ownership of this particular state
-
-	bc.futureBlocks, _ = lru.New(maxFutureBlocks)
-	bc.makeCache()
-
 	go bc.update()
-
 	return bc, nil
 }
 
@@ -139,13 +145,15 @@ func (bc *ChainManager) SetHead(head *types.Block) {
 	defer bc.mu.Unlock()
 
 	for block := bc.currentBlock; block != nil && block.Hash() != head.Hash(); block = bc.GetBlock(block.ParentHash()) {
-		bc.removeBlock(block)
+		DeleteBlock(bc.chainDb, block.Hash())
 	}
+	bc.headerCache.Purge()
+	bc.bodyCache.Purge()
+	bc.bodyRLPCache.Purge()
+	bc.blockCache.Purge()
+	bc.futureBlocks.Purge()
 
-	bc.cache, _ = lru.New(blockCacheLimit)
 	bc.currentBlock = head
-	bc.makeCache()
-
 	bc.setTotalDifficulty(head.Td)
 	bc.insert(head)
 	bc.setLastState()
@@ -199,11 +207,9 @@ func (bc *ChainManager) recover() bool {
 	if len(data) != 0 {
 		block := bc.GetBlock(common.BytesToHash(data))
 		if block != nil {
-			err := bc.chainDb.Put([]byte("LastBlock"), block.Hash().Bytes())
-			if err != nil {
-				glog.Fatalln("db write err:", err)
+			if err := WriteHead(bc.chainDb, block); err != nil {
+				glog.Fatalf("failed to write database head: %v", err)
 			}
-
 			bc.currentBlock = block
 			bc.lastBlockHash = block.Hash()
 			return true
@@ -213,14 +219,14 @@ func (bc *ChainManager) recover() bool {
 }
 
 func (bc *ChainManager) setLastState() error {
-	data, _ := bc.chainDb.Get([]byte("LastBlock"))
-	if len(data) != 0 {
-		block := bc.GetBlock(common.BytesToHash(data))
+	head := GetHeadHash(bc.chainDb)
+	if head != (common.Hash{}) {
+		block := bc.GetBlock(head)
 		if block != nil {
 			bc.currentBlock = block
 			bc.lastBlockHash = block.Hash()
 		} else {
-			glog.Infof("LastBlock (%x) not found. Recovering...\n", data)
+			glog.Infof("LastBlock (%x) not found. Recovering...\n", head)
 			if bc.recover() {
 				glog.Infof("Recover successful")
 			} else {
@@ -240,63 +246,37 @@ func (bc *ChainManager) setLastState() error {
 	return nil
 }
 
-func (bc *ChainManager) makeCache() {
-	bc.cache, _ = lru.New(blockCacheLimit)
-	// load in last `blockCacheLimit` - 1 blocks. Last block is the current.
-	bc.cache.Add(bc.genesisBlock.Hash(), bc.genesisBlock)
-	for _, block := range bc.GetBlocksFromHash(bc.currentBlock.Hash(), blockCacheLimit) {
-		bc.cache.Add(block.Hash(), block)
-	}
-}
-
+// Reset purges the entire blockchain, restoring it to its genesis state.
 func (bc *ChainManager) Reset() {
+	bc.ResetWithGenesisBlock(bc.genesisBlock)
+}
+
+// ResetWithGenesisBlock purges the entire blockchain, restoring it to the
+// specified genesis state.
+func (bc *ChainManager) ResetWithGenesisBlock(genesis *types.Block) {
 	bc.mu.Lock()
 	defer bc.mu.Unlock()
 
+	// Dump the entire block chain and purge the caches
 	for block := bc.currentBlock; block != nil; block = bc.GetBlock(block.ParentHash()) {
-		bc.removeBlock(block)
+		DeleteBlock(bc.chainDb, block.Hash())
 	}
+	bc.headerCache.Purge()
+	bc.bodyCache.Purge()
+	bc.bodyRLPCache.Purge()
+	bc.blockCache.Purge()
+	bc.futureBlocks.Purge()
 
-	bc.cache, _ = lru.New(blockCacheLimit)
+	// Prepare the genesis block and reinitialize the chain
+	bc.genesisBlock = genesis
+	bc.genesisBlock.Td = genesis.Difficulty()
 
-	// Prepare the genesis block
-	err := WriteBlock(bc.chainDb, bc.genesisBlock)
-	if err != nil {
-		glog.Fatalln("db err:", err)
+	if err := WriteBlock(bc.chainDb, bc.genesisBlock); err != nil {
+		glog.Fatalf("failed to write genesis block: %v", err)
 	}
-
 	bc.insert(bc.genesisBlock)
 	bc.currentBlock = bc.genesisBlock
-	bc.makeCache()
-
-	bc.setTotalDifficulty(common.Big("0"))
-}
-
-func (bc *ChainManager) removeBlock(block *types.Block) {
-	bc.chainDb.Delete(append(blockHashPre, block.Hash().Bytes()...))
-}
-
-func (bc *ChainManager) ResetWithGenesisBlock(gb *types.Block) {
-	bc.mu.Lock()
-	defer bc.mu.Unlock()
-
-	for block := bc.currentBlock; block != nil; block = bc.GetBlock(block.ParentHash()) {
-		bc.removeBlock(block)
-	}
-
-	// Prepare the genesis block
-	gb.Td = gb.Difficulty()
-	bc.genesisBlock = gb
-
-	err := WriteBlock(bc.chainDb, bc.genesisBlock)
-	if err != nil {
-		glog.Fatalln("db err:", err)
-	}
-
-	bc.insert(bc.genesisBlock)
-	bc.currentBlock = bc.genesisBlock
-	bc.makeCache()
-	bc.td = gb.Difficulty()
+	bc.setTotalDifficulty(genesis.Difficulty())
 }
 
 // Export writes the active chain to the given writer.
@@ -359,56 +339,130 @@ func (bc *ChainManager) Genesis() *types.Block {
 	return bc.genesisBlock
 }
 
-// Block fetching methods
+// HasHeader checks if a block header is present in the database or not, caching
+// it if present.
+func (bc *ChainManager) HasHeader(hash common.Hash) bool {
+	return bc.GetHeader(hash) != nil
+}
+
+// GetHeader retrieves a block header from the database by hash, caching it if
+// found.
+func (self *ChainManager) GetHeader(hash common.Hash) *types.Header {
+	// Short circuit if the header's already in the cache, retrieve otherwise
+	if header, ok := self.headerCache.Get(hash); ok {
+		return header.(*types.Header)
+	}
+	header := GetHeaderByHash(self.chainDb, hash)
+	if header == nil {
+		return nil
+	}
+	// Cache the found header for next time and return
+	self.headerCache.Add(header.Hash(), header)
+	return header
+}
+
+// GetHeaderByNumber retrieves a block header from the database by number,
+// caching it (associated with its hash) if found.
+func (self *ChainManager) GetHeaderByNumber(number uint64) *types.Header {
+	hash := GetHashByNumber(self.chainDb, number)
+	if hash == (common.Hash{}) {
+		return nil
+	}
+	return self.GetHeader(hash)
+}
+
+// GetBody retrieves a block body (transactions, uncles and total difficulty)
+// from the database by hash, caching it if found. The resion for the peculiar
+// pointer-to-slice return type is to differentiate between empty and inexistent
+// bodies.
+func (self *ChainManager) GetBody(hash common.Hash) (*[]*types.Transaction, *[]*types.Header) {
+	// Short circuit if the body's already in the cache, retrieve otherwise
+	if cached, ok := self.bodyCache.Get(hash); ok {
+		body := cached.(*storageBody)
+		return &body.Transactions, &body.Uncles
+	}
+	transactions, uncles, td := GetBodyByHash(self.chainDb, hash)
+	if td == nil {
+		return nil, nil
+	}
+	// Cache the found body for next time and return
+	self.bodyCache.Add(hash, &storageBody{
+		Transactions: transactions,
+		Uncles:       uncles,
+	})
+	return &transactions, &uncles
+}
+
+// GetBodyRLP retrieves a block body in RLP encoding from the database by hash,
+// caching it if found.
+func (self *ChainManager) GetBodyRLP(hash common.Hash) []byte {
+	// Short circuit if the body's already in the cache, retrieve otherwise
+	if cached, ok := self.bodyRLPCache.Get(hash); ok {
+		return cached.([]byte)
+	}
+	body, td := GetBodyRLPByHash(self.chainDb, hash)
+	if td == nil {
+		return nil
+	}
+	// Cache the found body for next time and return
+	self.bodyRLPCache.Add(hash, body)
+	return body
+}
+
+// HasBlock checks if a block is fully present in the database or not, caching
+// it if present.
 func (bc *ChainManager) HasBlock(hash common.Hash) bool {
 	return bc.GetBlock(hash) != nil
 }
 
-func (self *ChainManager) GetBlockHashesFromHash(hash common.Hash, max uint64) (chain []common.Hash) {
-	block := self.GetBlock(hash)
-	if block == nil {
-		return
-	}
-	// XXX Could be optimised by using a different database which only holds hashes (i.e., linked list)
-	for i := uint64(0); i < max; i++ {
-		block = self.GetBlock(block.ParentHash())
-		if block == nil {
-			break
-		}
-
-		chain = append(chain, block.Hash())
-		if block.Number().Cmp(common.Big0) <= 0 {
-			break
-		}
-	}
-
-	return
-}
-
+// GetBlock retrieves a block from the database by hash, caching it if found.
 func (self *ChainManager) GetBlock(hash common.Hash) *types.Block {
-	if block, ok := self.cache.Get(hash); ok {
+	// Short circuit if the block's already in the cache, retrieve otherwise
+	if block, ok := self.blockCache.Get(hash); ok {
 		return block.(*types.Block)
 	}
-
 	block := GetBlockByHash(self.chainDb, hash)
 	if block == nil {
 		return nil
 	}
-
-	// Add the block to the cache
-	self.cache.Add(hash, (*types.Block)(block))
-
-	return (*types.Block)(block)
+	// Cache the found block for next time and return
+	self.blockCache.Add(block.Hash(), block)
+	return block
 }
 
-func (self *ChainManager) GetBlockByNumber(num uint64) *types.Block {
-	self.mu.RLock()
-	defer self.mu.RUnlock()
-
-	return self.getBlockByNumber(num)
-
+// GetBlockByNumber retrieves a block from the database by number, caching it
+// (associated with its hash) if found.
+func (self *ChainManager) GetBlockByNumber(number uint64) *types.Block {
+	hash := GetHashByNumber(self.chainDb, number)
+	if hash == (common.Hash{}) {
+		return nil
+	}
+	return self.GetBlock(hash)
 }
 
+// GetBlockHashesFromHash retrieves a number of block hashes starting at a given
+// hash, fetching towards the genesis block.
+func (self *ChainManager) GetBlockHashesFromHash(hash common.Hash, max uint64) []common.Hash {
+	// Get the origin header from which to fetch
+	header := self.GetHeader(hash)
+	if header == nil {
+		return nil
+	}
+	// Iterate the headers until enough is collected or the genesis reached
+	chain := make([]common.Hash, 0, max)
+	for i := uint64(0); i < max; i++ {
+		if header = self.GetHeader(header.ParentHash); header == nil {
+			break
+		}
+		chain = append(chain, header.Hash())
+		if header.Number.Cmp(common.Big0) <= 0 {
+			break
+		}
+	}
+	return chain
+}
+
+// [deprecated by eth/62]
 // GetBlocksFromHash returns the block corresponding to hash and up to n-1 ancestors.
 func (self *ChainManager) GetBlocksFromHash(hash common.Hash, n int) (blocks []*types.Block) {
 	for i := 0; i < n; i++ {
@@ -422,11 +476,6 @@ func (self *ChainManager) GetBlocksFromHash(hash common.Hash, n int) (blocks []*
 	return
 }
 
-// non blocking version
-func (self *ChainManager) getBlockByNumber(num uint64) *types.Block {
-	return GetBlockByNumber(self.chainDb, num)
-}
-
 func (self *ChainManager) GetUnclesInChain(block *types.Block, length int) (uncles []*types.Header) {
 	for i := 0; block != nil && i < length; i++ {
 		uncles = append(uncles, block.Uncles()...)

core/chain_manager_test.go

@@ -388,7 +388,10 @@ func makeChainWithDiff(genesis *types.Block, d []int, seed byte) []*types.Block
 func chm(genesis *types.Block, db common.Database) *ChainManager {
 	var eventMux event.TypeMux
 	bc := &ChainManager{chainDb: db, genesisBlock: genesis, eventMux: &eventMux, pow: FakePow{}}
-	bc.cache, _ = lru.New(100)
+	bc.headerCache, _ = lru.New(100)
+	bc.bodyCache, _ = lru.New(100)
+	bc.bodyRLPCache, _ = lru.New(100)
+	bc.blockCache, _ = lru.New(100)
 	bc.futureBlocks, _ = lru.New(100)
 	bc.processor = bproc{}
 	bc.ResetWithGenesisBlock(genesis)

core/chain_util.go

@@ -29,6 +29,8 @@ import (
 )
 
 var (
+	headKey = []byte("LastBlock")
+
 	headerHashPre = []byte("header-hash-")
 	bodyHashPre   = []byte("body-hash-")
 	blockNumPre   = []byte("block-num-")
@@ -120,6 +122,24 @@ type storageBody struct {
 	Uncles       []*types.Header
 }
 
+// GetHashByNumber retrieves a hash assigned to a canonical block number.
+func GetHashByNumber(db common.Database, number uint64) common.Hash {
+	data, _ := db.Get(append(blockNumPre, big.NewInt(int64(number)).Bytes()...))
+	if len(data) == 0 {
+		return common.Hash{}
+	}
+	return common.BytesToHash(data)
+}
+
+// GetHeadHash retrieves the hash of the current canonical head block.
+func GetHeadHash(db common.Database) common.Hash {
+	data, _ := db.Get(headKey)
+	if len(data) == 0 {
+		return common.Hash{}
+	}
+	return common.BytesToHash(data)
+}
+
 // GetHeaderRLPByHash retrieves a block header in its raw RLP database encoding,
 // or nil if the header's not found.
 func GetHeaderRLPByHash(db common.Database, hash common.Hash) []byte {
@@ -202,24 +222,24 @@ func GetBlockByNumber(db common.Database, number uint64) *types.Block {
 	return GetBlockByHash(db, common.BytesToHash(key))
 }
 
-// WriteCanonNumber writes the canonical hash for the given block
-func WriteCanonNumber(db common.Database, block *types.Block) error {
-	key := append(blockNumPre, block.Number().Bytes()...)
-	err := db.Put(key, block.Hash().Bytes())
-	if err != nil {
+// WriteCanonNumber stores the canonical hash for the given block number.
+func WriteCanonNumber(db common.Database, hash common.Hash, number uint64) error {
+	key := append(blockNumPre, big.NewInt(int64(number)).Bytes()...)
+	if err := db.Put(key, hash.Bytes()); err != nil {
+		glog.Fatalf("failed to store number to hash mapping into database: %v", err)
 		return err
 	}
 	return nil
 }
 
-// WriteHead force writes the current head
+// WriteHead updates the head block of the chain database.
 func WriteHead(db common.Database, block *types.Block) error {
-	err := WriteCanonNumber(db, block)
-	if err != nil {
+	if err := WriteCanonNumber(db, block.Hash(), block.NumberU64()); err != nil {
+		glog.Fatalf("failed to store canonical number into database: %v", err)
 		return err
 	}
-	err = db.Put([]byte("LastBlock"), block.Hash().Bytes())
-	if err != nil {
+	if err := db.Put(headKey, block.Hash().Bytes()); err != nil {
+		glog.Fatalf("failed to store last block into database: %v", err)
 		return err
 	}
 	return nil
@@ -272,6 +292,22 @@ func WriteBlock(db common.Database, block *types.Block) error {
 	return nil
 }
 
+// DeleteHeader removes all block header data associated with a hash.
+func DeleteHeader(db common.Database, hash common.Hash) {
+	db.Delete(append(headerHashPre, hash.Bytes()...))
+}
+
+// DeleteBody removes all block body data associated with a hash.
+func DeleteBody(db common.Database, hash common.Hash) {
+	db.Delete(append(bodyHashPre, hash.Bytes()...))
+}
+
+// DeleteBlock removes all block data associated with a hash.
+func DeleteBlock(db common.Database, hash common.Hash) {
+	DeleteHeader(db, hash)
+	DeleteBody(db, hash)
+}
+
 // [deprecated by eth/63]
 // GetBlockByHashOld returns the old combined block corresponding to the hash
 // or nil if not found. This method is only used by the upgrade mechanism to

core/genesis.go

@@ -86,7 +86,7 @@ func WriteGenesisBlock(chainDb common.Database, reader io.Reader) (*types.Block,
 
 	if block := GetBlockByHash(chainDb, block.Hash()); block != nil {
 		glog.V(logger.Info).Infoln("Genesis block already in chain. Writing canonical number")
-		err := WriteCanonNumber(chainDb, block)
+		err := WriteCanonNumber(chainDb, block.Hash(), block.NumberU64())
 		if err != nil {
 			return nil, err
 		}

eth/handler.go

@@ -345,33 +345,33 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		if err := msg.Decode(&query); err != nil {
 			return errResp(ErrDecode, "%v: %v", msg, err)
 		}
-		// Gather blocks until the fetch or network limits is reached
+		// Gather headers until the fetch or network limits is reached
 		var (
 			bytes   common.StorageSize
 			headers []*types.Header
 			unknown bool
 		)
 		for !unknown && len(headers) < int(query.Amount) && bytes < softResponseLimit && len(headers) < downloader.MaxHeaderFetch {
-			// Retrieve the next block satisfying the query
-			var origin *types.Block
+			// Retrieve the next header satisfying the query
+			var origin *types.Header
 			if query.Origin.Hash != (common.Hash{}) {
-				origin = pm.chainman.GetBlock(query.Origin.Hash)
+				origin = pm.chainman.GetHeader(query.Origin.Hash)
 			} else {
-				origin = pm.chainman.GetBlockByNumber(query.Origin.Number)
+				origin = pm.chainman.GetHeaderByNumber(query.Origin.Number)
 			}
 			if origin == nil {
 				break
 			}
-			headers = append(headers, origin.Header())
-			bytes += origin.Size()
+			headers = append(headers, origin)
+			bytes += 500 // Approximate, should be good enough estimate
 
-			// Advance to the next block of the query
+			// Advance to the next header of the query
 			switch {
 			case query.Origin.Hash != (common.Hash{}) && query.Reverse:
 				// Hash based traversal towards the genesis block
 				for i := 0; i < int(query.Skip)+1; i++ {
-					if block := pm.chainman.GetBlock(query.Origin.Hash); block != nil {
-						query.Origin.Hash = block.ParentHash()
+					if header := pm.chainman.GetHeader(query.Origin.Hash); header != nil {
+						query.Origin.Hash = header.ParentHash
 					} else {
 						unknown = true
 						break
@@ -379,9 +379,9 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 				}
 			case query.Origin.Hash != (common.Hash{}) && !query.Reverse:
 				// Hash based traversal towards the leaf block
-				if block := pm.chainman.GetBlockByNumber(origin.NumberU64() + query.Skip + 1); block != nil {
-					if pm.chainman.GetBlockHashesFromHash(block.Hash(), query.Skip+1)[query.Skip] == query.Origin.Hash {
-						query.Origin.Hash = block.Hash()
+				if header := pm.chainman.GetHeaderByNumber(origin.Number.Uint64() + query.Skip + 1); header != nil {
+					if pm.chainman.GetBlockHashesFromHash(header.Hash(), query.Skip+1)[query.Skip] == query.Origin.Hash {
+						query.Origin.Hash = header.Hash()
 					} else {
 						unknown = true
 					}
@@ -452,8 +452,8 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		// Gather blocks until the fetch or network limits is reached
 		var (
 			hash   common.Hash
-			bytes  common.StorageSize
-			bodies []*blockBody
+			bytes  int
+			bodies []*blockBodyRLP
 		)
 		for bytes < softResponseLimit && len(bodies) < downloader.MaxBlockFetch {
 			// Retrieve the hash of the next block
@@ -462,13 +462,14 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 			} else if err != nil {
 				return errResp(ErrDecode, "msg %v: %v", msg, err)
 			}
-			// Retrieve the requested block, stopping if enough was found
-			if block := pm.chainman.GetBlock(hash); block != nil {
-				bodies = append(bodies, &blockBody{Transactions: block.Transactions(), Uncles: block.Uncles()})
-				bytes += block.Size()
+			// Retrieve the requested block body, stopping if enough was found
+			if data := pm.chainman.GetBodyRLP(hash); len(data) != 0 {
+				body := blockBodyRLP(data)
+				bodies = append(bodies, &body)
+				bytes += len(body)
 			}
 		}
-		return p.SendBlockBodies(bodies)
+		return p.SendBlockBodiesRLP(bodies)
 
 	case p.version >= eth63 && msg.Code == GetNodeDataMsg:
 		// Decode the retrieval message

eth/peer.go

@@ -184,6 +184,12 @@ func (p *peer) SendBlockBodies(bodies []*blockBody) error {
 	return p2p.Send(p.rw, BlockBodiesMsg, blockBodiesData(bodies))
 }
 
+// SendBlockBodiesRLP sends a batch of block contents to the remote peer from
+// an already RLP encoded format.
+func (p *peer) SendBlockBodiesRLP(bodies []*blockBodyRLP) error {
+	return p2p.Send(p.rw, BlockBodiesMsg, blockBodiesRLPData(bodies))
+}
+
 // SendNodeData sends a batch of arbitrary internal data, corresponding to the
 // hashes requested.
 func (p *peer) SendNodeData(data [][]byte) error {

eth/protocol.go

@@ -213,6 +213,22 @@ type blockBody struct {
 // blockBodiesData is the network packet for block content distribution.
 type blockBodiesData []*blockBody
 
+// blockBodyRLP represents the RLP encoded data content of a single block.
+type blockBodyRLP []byte
+
+// EncodeRLP is a specialized encoder for a block body to pass the already
+// encoded body RLPs from the database on, without double encoding.
+func (b *blockBodyRLP) EncodeRLP(w io.Writer) error {
+	if _, err := w.Write([]byte(*b)); err != nil {
+		return err
+	}
+	return nil
+}
+
+// blockBodiesRLPData is the network packet for block content distribution
+// based on original RLP formatting (i.e. skip the db-decode/proto-encode).
+type blockBodiesRLPData []*blockBodyRLP
+
 // nodeDataData is the network response packet for a node data retrieval.
 type nodeDataData []struct {
 	Value []byte