eth/downloader: add fast and light sync strategies

core/transaction_util.go

@@ -140,13 +140,12 @@ func GetBlockReceipts(db ethdb.Database, hash common.Hash) types.Receipts {
 	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)
+	receipts := new(types.Receipts)
+	if err := rlp.DecodeBytes(data, receipts); err != nil {
+		glog.V(logger.Error).Infof("invalid receipt array RLP for hash %x: %v", hash, err)
+		return nil
 	}
-	return receipts
+	return *receipts
 }
 
 // PutBlockReceipts stores the block's transactions associated receipts

core/types/block.go

@@ -172,8 +172,8 @@ type storageblock struct {
 }
 
 var (
-	emptyRootHash  = DeriveSha(Transactions{})
-	emptyUncleHash = CalcUncleHash(nil)
+	EmptyRootHash  = DeriveSha(Transactions{})
+	EmptyUncleHash = CalcUncleHash(nil)
 )
 
 // NewBlock creates a new block. The input data is copied,
@@ -188,7 +188,7 @@ func NewBlock(header *Header, txs []*Transaction, uncles []*Header, receipts []*
 
 	// TODO: panic if len(txs) != len(receipts)
 	if len(txs) == 0 {
-		b.header.TxHash = emptyRootHash
+		b.header.TxHash = EmptyRootHash
 	} else {
 		b.header.TxHash = DeriveSha(Transactions(txs))
 		b.transactions = make(Transactions, len(txs))
@@ -196,7 +196,7 @@ func NewBlock(header *Header, txs []*Transaction, uncles []*Header, receipts []*
 	}
 
 	if len(receipts) == 0 {
-		b.header.ReceiptHash = emptyRootHash
+		b.header.ReceiptHash = EmptyRootHash
 	} else {
 		b.header.ReceiptHash = DeriveSha(Receipts(receipts))
 		b.header.Bloom = CreateBloom(receipts)
@@ -205,7 +205,7 @@ func NewBlock(header *Header, txs []*Transaction, uncles []*Header, receipts []*
 	}
 
 	if len(uncles) == 0 {
-		b.header.UncleHash = emptyUncleHash
+		b.header.UncleHash = EmptyUncleHash
 	} else {
 		b.header.UncleHash = CalcUncleHash(uncles)
 		b.uncles = make([]*Header, len(uncles))

eth/downloader/downloader.go

@@ -19,8 +19,10 @@ package downloader
 
 import (
 	"errors"
+	"fmt"
 	"math"
 	"math/big"
+	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -32,70 +34,96 @@ import (
 	"github.com/ethereum/go-ethereum/logger/glog"
 )
 
-const (
-	eth61 = 61 // Constant to check for old protocol support
-	eth62 = 62 // Constant to check for new protocol support
-)
-
 var (
-	MaxHashFetch     = 512 // Amount of hashes to be fetched per retrieval request
-	MaxBlockFetch    = 128 // Amount of blocks to be fetched per retrieval request
-	MaxHeaderFetch   = 192 // Amount of block headers to be fetched per retrieval request
-	MaxBodyFetch     = 128 // Amount of block bodies to be fetched per retrieval request
-	MaxStateFetch    = 384 // Amount of node state values to allow fetching per request
-	MaxReceiptsFetch = 384 // Amount of transaction receipts to allow fetching per request
-
-	hashTTL      = 5 * time.Second  // [eth/61] Time it takes for a hash request to time out
-	blockSoftTTL = 3 * time.Second  // [eth/61] Request completion threshold for increasing or decreasing a peer's bandwidth
-	blockHardTTL = 3 * blockSoftTTL // [eth/61] Maximum time allowance before a block request is considered expired
-	headerTTL    = 5 * time.Second  // [eth/62] Time it takes for a header request to time out
-	bodySoftTTL  = 3 * time.Second  // [eth/62] Request completion threshold for increasing or decreasing a peer's bandwidth
-	bodyHardTTL  = 3 * bodySoftTTL  // [eth/62] Maximum time allowance before a block body request is considered expired
-
-	maxQueuedHashes  = 256 * 1024 // [eth/61] Maximum number of hashes to queue for import (DOS protection)
-	maxQueuedHeaders = 256 * 1024 // [eth/62] Maximum number of headers to queue for import (DOS protection)
-	maxBlockProcess  = 256        // Number of blocks to import at once into the chain
+	MaxHashFetch    = 512 // Amount of hashes to be fetched per retrieval request
+	MaxBlockFetch   = 128 // Amount of blocks to be fetched per retrieval request
+	MaxHeaderFetch  = 192 // Amount of block headers to be fetched per retrieval request
+	MaxBodyFetch    = 128 // Amount of block bodies to be fetched per retrieval request
+	MaxStateFetch   = 384 // Amount of node state values to allow fetching per request
+	MaxReceiptFetch = 256 // Amount of transaction receipts to allow fetching per request
+
+	hashTTL        = 5 * time.Second    // [eth/61] Time it takes for a hash request to time out
+	blockSoftTTL   = 3 * time.Second    // [eth/61] Request completion threshold for increasing or decreasing a peer's bandwidth
+	blockHardTTL   = 3 * blockSoftTTL   // [eth/61] Maximum time allowance before a block request is considered expired
+	headerTTL      = 5 * time.Second    // [eth/62] Time it takes for a header request to time out
+	bodySoftTTL    = 3 * time.Second    // [eth/62] Request completion threshold for increasing or decreasing a peer's bandwidth
+	bodyHardTTL    = 3 * bodySoftTTL    // [eth/62] Maximum time allowance before a block body request is considered expired
+	receiptSoftTTL = 3 * time.Second    // [eth/63] Request completion threshold for increasing or decreasing a peer's bandwidth
+	receiptHardTTL = 3 * receiptSoftTTL // [eth/63] Maximum time allowance before a block body request is considered expired
+
+	maxQueuedHashes   = 256 * 1024 // [eth/61] Maximum number of hashes to queue for import (DOS protection)
+	maxQueuedHeaders  = 256 * 1024 // [eth/62] Maximum number of headers to queue for import (DOS protection)
+	maxResultsProcess = 256        // Number of download results to import at once into the chain
+
+	headerCheckFrequency = 64   // Verification frequency of the downloaded headers during fast sync
+	minCheckedHeaders    = 1024 // Number of headers to verify fully when approaching the chain head
+	minFullBlocks        = 1024 // Number of blocks to retrieve fully even in fast sync
 )
 
 var (
-	errBusy              = errors.New("busy")
-	errUnknownPeer       = errors.New("peer is unknown or unhealthy")
-	errBadPeer           = errors.New("action from bad peer ignored")
-	errStallingPeer      = errors.New("peer is stalling")
-	errNoPeers           = errors.New("no peers to keep download active")
-	errPendingQueue      = errors.New("pending items in queue")
-	errTimeout           = errors.New("timeout")
-	errEmptyHashSet      = errors.New("empty hash set by peer")
-	errEmptyHeaderSet    = errors.New("empty header set by peer")
-	errPeersUnavailable  = errors.New("no peers available or all peers tried for block download process")
-	errAlreadyInPool     = errors.New("hash already in pool")
-	errInvalidChain      = errors.New("retrieved hash chain is invalid")
-	errInvalidBody       = errors.New("retrieved block body is invalid")
-	errCancelHashFetch   = errors.New("hash fetching canceled (requested)")
-	errCancelBlockFetch  = errors.New("block downloading canceled (requested)")
-	errCancelHeaderFetch = errors.New("block header fetching canceled (requested)")
-	errCancelBodyFetch   = errors.New("block body downloading canceled (requested)")
-	errNoSyncActive      = errors.New("no sync active")
+	errBusy               = errors.New("busy")
+	errUnknownPeer        = errors.New("peer is unknown or unhealthy")
+	errBadPeer            = errors.New("action from bad peer ignored")
+	errStallingPeer       = errors.New("peer is stalling")
+	errNoPeers            = errors.New("no peers to keep download active")
+	errPendingQueue       = errors.New("pending items in queue")
+	errTimeout            = errors.New("timeout")
+	errEmptyHashSet       = errors.New("empty hash set by peer")
+	errEmptyHeaderSet     = errors.New("empty header set by peer")
+	errPeersUnavailable   = errors.New("no peers available or all tried for download")
+	errAlreadyInPool      = errors.New("hash already in pool")
+	errInvalidChain       = errors.New("retrieved hash chain is invalid")
+	errInvalidBlock       = errors.New("retrieved block is invalid")
+	errInvalidBody        = errors.New("retrieved block body is invalid")
+	errInvalidReceipt     = errors.New("retrieved receipt is invalid")
+	errCancelHashFetch    = errors.New("hash download canceled (requested)")
+	errCancelBlockFetch   = errors.New("block download canceled (requested)")
+	errCancelHeaderFetch  = errors.New("block header download canceled (requested)")
+	errCancelBodyFetch    = errors.New("block body download canceled (requested)")
+	errCancelReceiptFetch = errors.New("receipt download canceled (requested)")
+	errNoSyncActive       = errors.New("no sync active")
 )
 
-// hashCheckFn is a callback type for verifying a hash's presence in the local chain.
-type hashCheckFn func(common.Hash) bool
+// headerCheckFn is a callback type for verifying a header's presence in the local chain.
+type headerCheckFn func(common.Hash) bool
+
+// blockCheckFn is a callback type for verifying a block's presence in the local chain.
+type blockCheckFn func(common.Hash) bool
+
+// headerRetrievalFn is a callback type for retrieving a header from the local chain.
+type headerRetrievalFn func(common.Hash) *types.Header
 
 // blockRetrievalFn is a callback type for retrieving a block from the local chain.
 type blockRetrievalFn func(common.Hash) *types.Block
 
-// headRetrievalFn is a callback type for retrieving the head block from the local chain.
-type headRetrievalFn func() *types.Block
+// headHeaderRetrievalFn is a callback type for retrieving the head header from the local chain.
+type headHeaderRetrievalFn func() *types.Header
+
+// headBlockRetrievalFn is a callback type for retrieving the head block from the local chain.
+type headBlockRetrievalFn func() *types.Block
 
 // tdRetrievalFn is a callback type for retrieving the total difficulty of a local block.
 type tdRetrievalFn func(common.Hash) *big.Int
 
-// chainInsertFn is a callback type to insert a batch of blocks into the local chain.
-type chainInsertFn func(types.Blocks) (int, error)
+// headerChainInsertFn is a callback type to insert a batch of headers into the local chain.
+type headerChainInsertFn func([]*types.Header, bool) (int, error)
+
+// blockChainInsertFn is a callback type to insert a batch of blocks into the local chain.
+type blockChainInsertFn func(types.Blocks) (int, error)
+
+// receiptChainInsertFn is a callback type to insert a batch of receipts into the local chain.
+type receiptChainInsertFn func(types.Blocks, []types.Receipts) (int, error)
 
 // peerDropFn is a callback type for dropping a peer detected as malicious.
 type peerDropFn func(id string)
 
+// dataPack is a data message returned by a peer for some query.
+type dataPack interface {
+	PeerId() string
+	Empty() bool
+	Stats() string
+}
+
 // hashPack is a batch of block hashes returned by a peer (eth/61).
 type hashPack struct {
 	peerId string
@@ -121,8 +149,33 @@ type bodyPack struct {
 	uncles       [][]*types.Header
 }
 
+// PeerId retrieves the origin peer who sent this block body packet.
+func (p *bodyPack) PeerId() string { return p.peerId }
+
+// Empty returns whether the no block bodies were delivered.
+func (p *bodyPack) Empty() bool { return len(p.transactions) == 0 || len(p.uncles) == 0 }
+
+// Stats creates a textual stats report for logging purposes.
+func (p *bodyPack) Stats() string { return fmt.Sprintf("%d:%d", len(p.transactions), len(p.uncles)) }
+
+// receiptPack is a batch of receipts returned by a peer.
+type receiptPack struct {
+	peerId   string
+	receipts [][]*types.Receipt
+}
+
+// PeerId retrieves the origin peer who sent this receipt packet.
+func (p *receiptPack) PeerId() string { return p.peerId }
+
+// Empty returns whether the no receipts were delivered.
+func (p *receiptPack) Empty() bool { return len(p.receipts) == 0 }
+
+// Stats creates a textual stats report for logging purposes.
+func (p *receiptPack) Stats() string { return fmt.Sprintf("%d", len(p.receipts)) }
+
 type Downloader struct {
-	mux *event.TypeMux
+	mode SyncMode       // Synchronisation mode defining the strategies used
+	mux  *event.TypeMux // Event multiplexer to announce sync operation events
 
 	queue *queue   // Scheduler for selecting the hashes to download
 	peers *peerSet // Set of active peers from which download can proceed
@@ -135,12 +188,17 @@ type Downloader struct {
 	syncStatsLock   sync.RWMutex // Lock protecting the sync stats fields
 
 	// Callbacks
-	hasBlock    hashCheckFn      // Checks if a block is present in the chain
-	getBlock    blockRetrievalFn // Retrieves a block from the chain
-	headBlock   headRetrievalFn  // Retrieves the head block from the chain
-	getTd       tdRetrievalFn    // Retrieves the TD of a block from the chain
-	insertChain chainInsertFn    // Injects a batch of blocks into the chain
-	dropPeer    peerDropFn       // Drops a peer for misbehaving
+	hasHeader      headerCheckFn         // Checks if a header is present in the chain
+	hasBlock       blockCheckFn          // Checks if a block is present in the chain
+	getHeader      headerRetrievalFn     // Retrieves a header from the chain
+	getBlock       blockRetrievalFn      // Retrieves a block from the chain
+	headHeader     headHeaderRetrievalFn // Retrieves the head header from the chain
+	headBlock      headBlockRetrievalFn  // Retrieves the head block from the chain
+	getTd          tdRetrievalFn         // Retrieves the TD of a block from the chain
+	insertHeaders  headerChainInsertFn   // Injects a batch of headers into the chain
+	insertBlocks   blockChainInsertFn    // Injects a batch of blocks into the chain
+	insertReceipts receiptChainInsertFn  // Injects a batch of blocks and their receipts into the chain
+	dropPeer       peerDropFn            // Drops a peer for misbehaving
 
 	// Status
 	synchroniseMock func(id string, hash common.Hash) error // Replacement for synchronise during testing
@@ -149,46 +207,56 @@ type Downloader struct {
 	notified        int32
 
 	// Channels
-	newPeerCh chan *peer
-	hashCh    chan hashPack   // [eth/61] Channel receiving inbound hashes
-	blockCh   chan blockPack  // [eth/61] Channel receiving inbound blocks
-	headerCh  chan headerPack // [eth/62] Channel receiving inbound block headers
-	bodyCh    chan bodyPack   // [eth/62] Channel receiving inbound block bodies
-	wakeCh    chan bool       // Channel to signal the block/body fetcher of new tasks
+	newPeerCh     chan *peer
+	hashCh        chan hashPack   // [eth/61] Channel receiving inbound hashes
+	blockCh       chan blockPack  // [eth/61] Channel receiving inbound blocks
+	headerCh      chan headerPack // [eth/62] Channel receiving inbound block headers
+	bodyCh        chan dataPack   // [eth/62] Channel receiving inbound block bodies
+	receiptCh     chan dataPack   // [eth/63] Channel receiving inbound receipts
+	blockWakeCh   chan bool       // [eth/61] Channel to signal the block fetcher of new tasks
+	bodyWakeCh    chan bool       // [eth/62] Channel to signal the block body fetcher of new tasks
+	receiptWakeCh chan bool       // [eth/63] Channel to signal the receipt fetcher of new tasks
 
 	cancelCh   chan struct{} // Channel to cancel mid-flight syncs
 	cancelLock sync.RWMutex  // Lock to protect the cancel channel in delivers
 
 	// Testing hooks
-	syncInitHook    func(uint64, uint64)  // Method to call upon initiating a new sync run
-	bodyFetchHook   func([]*types.Header) // Method to call upon starting a block body fetch
-	chainInsertHook func([]*Block)        // Method to call upon inserting a chain of blocks (possibly in multiple invocations)
-}
-
-// Block is an origin-tagged blockchain block.
-type Block struct {
-	RawBlock   *types.Block
-	OriginPeer string
+	syncInitHook     func(uint64, uint64)  // Method to call upon initiating a new sync run
+	bodyFetchHook    func([]*types.Header) // Method to call upon starting a block body fetch
+	receiptFetchHook func([]*types.Header) // Method to call upon starting a receipt fetch
+	chainInsertHook  func([]*fetchResult)  // Method to call upon inserting a chain of blocks (possibly in multiple invocations)
 }
 
 // New creates a new downloader to fetch hashes and blocks from remote peers.
-func New(mux *event.TypeMux, hasBlock hashCheckFn, getBlock blockRetrievalFn, headBlock headRetrievalFn, getTd tdRetrievalFn, insertChain chainInsertFn, dropPeer peerDropFn) *Downloader {
+func New(mode SyncMode, mux *event.TypeMux, hasHeader headerCheckFn, hasBlock blockCheckFn, getHeader headerRetrievalFn, getBlock blockRetrievalFn,
+	headHeader headHeaderRetrievalFn, headBlock headBlockRetrievalFn, getTd tdRetrievalFn, insertHeaders headerChainInsertFn, insertBlocks blockChainInsertFn,
+	insertReceipts receiptChainInsertFn, dropPeer peerDropFn) *Downloader {
+
 	return &Downloader{
-		mux:         mux,
-		queue:       newQueue(),
-		peers:       newPeerSet(),
-		hasBlock:    hasBlock,
-		getBlock:    getBlock,
-		headBlock:   headBlock,
-		getTd:       getTd,
-		insertChain: insertChain,
-		dropPeer:    dropPeer,
-		newPeerCh:   make(chan *peer, 1),
-		hashCh:      make(chan hashPack, 1),
-		blockCh:     make(chan blockPack, 1),
-		headerCh:    make(chan headerPack, 1),
-		bodyCh:      make(chan bodyPack, 1),
-		wakeCh:      make(chan bool, 1),
+		mode:           mode,
+		mux:            mux,
+		queue:          newQueue(),
+		peers:          newPeerSet(),
+		hasHeader:      hasHeader,
+		hasBlock:       hasBlock,
+		getHeader:      getHeader,
+		getBlock:       getBlock,
+		headHeader:     headHeader,
+		headBlock:      headBlock,
+		getTd:          getTd,
+		insertHeaders:  insertHeaders,
+		insertBlocks:   insertBlocks,
+		insertReceipts: insertReceipts,
+		dropPeer:       dropPeer,
+		newPeerCh:      make(chan *peer, 1),
+		hashCh:         make(chan hashPack, 1),
+		blockCh:        make(chan blockPack, 1),
+		headerCh:       make(chan headerPack, 1),
+		bodyCh:         make(chan dataPack, 1),
+		receiptCh:      make(chan dataPack, 1),
+		blockWakeCh:    make(chan bool, 1),
+		bodyWakeCh:     make(chan bool, 1),
+		receiptWakeCh:  make(chan bool, 1),
 	}
 }
 
@@ -211,10 +279,10 @@ func (d *Downloader) Synchronising() bool {
 // used for fetching hashes and blocks from.
 func (d *Downloader) RegisterPeer(id string, version int, head common.Hash,
 	getRelHashes relativeHashFetcherFn, getAbsHashes absoluteHashFetcherFn, getBlocks blockFetcherFn, // eth/61 callbacks, remove when upgrading
-	getRelHeaders relativeHeaderFetcherFn, getAbsHeaders absoluteHeaderFetcherFn, getBlockBodies blockBodyFetcherFn) error {
+	getRelHeaders relativeHeaderFetcherFn, getAbsHeaders absoluteHeaderFetcherFn, getBlockBodies blockBodyFetcherFn, getReceipts receiptFetcherFn) error {
 
 	glog.V(logger.Detail).Infoln("Registering peer", id)
-	if err := d.peers.Register(newPeer(id, version, head, getRelHashes, getAbsHashes, getBlocks, getRelHeaders, getAbsHeaders, getBlockBodies)); err != nil {
+	if err := d.peers.Register(newPeer(id, version, head, getRelHashes, getAbsHashes, getBlocks, getRelHeaders, getAbsHeaders, getBlockBodies, getReceipts)); err != nil {
 		glog.V(logger.Error).Infoln("Register failed:", err)
 		return err
 	}
@@ -222,13 +290,15 @@ func (d *Downloader) RegisterPeer(id string, version int, head common.Hash,
 }
 
 // UnregisterPeer remove a peer from the known list, preventing any action from
-// the specified peer.
+// the specified peer. An effort is also made to return any pending fetches into
+// the queue.
 func (d *Downloader) UnregisterPeer(id string) error {
 	glog.V(logger.Detail).Infoln("Unregistering peer", id)
 	if err := d.peers.Unregister(id); err != nil {
 		glog.V(logger.Error).Infoln("Unregister failed:", err)
 		return err
 	}
+	d.queue.Revoke(id)
 	return nil
 }
 
@@ -275,16 +345,18 @@ func (d *Downloader) synchronise(id string, hash common.Hash, td *big.Int) error
 		glog.V(logger.Info).Infoln("Block synchronisation started")
 	}
 	// Abort if the queue still contains some leftover data
-	if _, cached := d.queue.Size(); cached > 0 && d.queue.GetHeadBlock() != nil {
+	if d.queue.GetHeadResult() != nil {
 		return errPendingQueue
 	}
-	// Reset the queue and peer set to clean any internal leftover state
+	// Reset the queue, peer set and wake channels to clean any internal leftover state
 	d.queue.Reset()
 	d.peers.Reset()
 
-	select {
-	case <-d.wakeCh:
-	default:
+	for _, ch := range []chan bool{d.blockWakeCh, d.bodyWakeCh, d.receiptWakeCh} {
+		select {
+		case <-ch:
+		default:
+		}
 	}
 	// Create cancel channel for aborting mid-flight
 	d.cancelLock.Lock()
@@ -299,12 +371,13 @@ func (d *Downloader) synchronise(id string, hash common.Hash, td *big.Int) error
 	return d.syncWithPeer(p, hash, td)
 }
 
+/*
 // Has checks if the downloader knows about a particular hash, meaning that its
 // either already downloaded of pending retrieval.
 func (d *Downloader) Has(hash common.Hash) bool {
 	return d.queue.Has(hash)
 }
-
+*/
 // syncWithPeer starts a block synchronization based on the hash chain from the
 // specified peer and head hash.
 func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err error) {
@@ -323,7 +396,7 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 	defer glog.V(logger.Debug).Infof("Synchronisation terminated")
 
 	switch {
-	case p.version == eth61:
+	case p.version == 61:
 		// Look up the sync boundaries: the common ancestor and the target block
 		latest, err := d.fetchHeight61(p)
 		if err != nil {
@@ -344,6 +417,8 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 		if d.syncInitHook != nil {
 			d.syncInitHook(origin, latest)
 		}
+		d.queue.Prepare(origin+1, 1)
+
 		errc := make(chan error, 2)
 		go func() { errc <- d.fetchHashes61(p, td, origin+1) }()
 		go func() { errc <- d.fetchBlocks61(origin + 1) }()
@@ -356,7 +431,7 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 		}
 		return <-errc
 
-	case p.version >= eth62:
+	case p.version >= 62:
 		// Look up the sync boundaries: the common ancestor and the target block
 		latest, err := d.fetchHeight(p)
 		if err != nil {
@@ -373,21 +448,32 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 		d.syncStatsHeight = latest
 		d.syncStatsLock.Unlock()
 
-		// Initiate the sync using a  concurrent hash and block retrieval algorithm
+		// Initiate the sync using a  concurrent header and content retrieval algorithm
+		parts := 1
+		if d.mode == FastSync {
+			parts = 2 // receipts are fetched too
+		}
+		d.queue.Prepare(origin+1, parts)
+
 		if d.syncInitHook != nil {
 			d.syncInitHook(origin, latest)
 		}
-		errc := make(chan error, 2)
-		go func() { errc <- d.fetchHeaders(p, td, origin+1) }()
-		go func() { errc <- d.fetchBodies(origin + 1) }()
-
-		// If any fetcher fails, cancel the other
-		if err := <-errc; err != nil {
-			d.cancel()
-			<-errc
-			return err
+		errc := make(chan error, 3)
+		go func() { errc <- d.fetchHeaders(p, td, origin+1) }() // Headers are always retrieved
+		go func() { errc <- d.fetchReceipts(origin + 1) }()     // Receipts are retrieved during fast sync
+		go func() { errc <- d.fetchBodies(origin + 1) }()       // Bodies are retrieved during normal sync
+
+		// If any fetcher fails, cancel the others
+		var fail error
+		for i := 0; i < cap(errc); i++ {
+			if err := <-errc; err != nil {
+				if fail == nil {
+					fail = err
+					d.cancel()
+				}
+			}
 		}
-		return <-errc
+		return fail
 
 	default:
 		// Something very wrong, stop right here
@@ -637,7 +723,7 @@ func (d *Downloader) fetchHashes61(p *peer, td *big.Int, from uint64) error {
 				glog.V(logger.Debug).Infof("%v: no available hashes", p)
 
 				select {
-				case d.wakeCh <- false:
+				case d.blockWakeCh <- false:
 				case <-d.cancelCh:
 				}
 				// If no hashes were retrieved at all, the peer violated it's TD promise that it had a
@@ -660,24 +746,24 @@ func (d *Downloader) fetchHashes61(p *peer, td *big.Int, from uint64) error {
 			gotHashes = true
 
 			// Otherwise insert all the new hashes, aborting in case of junk
-			glog.V(logger.Detail).Infof("%v: inserting %d hashes from #%d", p, len(hashPack.hashes), from)
+			glog.V(logger.Detail).Infof("%v: scheduling %d hashes from #%d", p, len(hashPack.hashes), from)
 
-			inserts := d.queue.Insert61(hashPack.hashes, true)
+			inserts := d.queue.Schedule61(hashPack.hashes, true)
 			if len(inserts) != len(hashPack.hashes) {
 				glog.V(logger.Debug).Infof("%v: stale hashes", p)
 				return errBadPeer
 			}
 			// Notify the block fetcher of new hashes, but stop if queue is full
-			if d.queue.Pending() < maxQueuedHashes {
+			if d.queue.PendingBlocks() < maxQueuedHashes {
 				// We still have hashes to fetch, send continuation wake signal (potential)
 				select {
-				case d.wakeCh <- true:
+				case d.blockWakeCh <- true:
 				default:
 				}
 			} else {
 				// Hash limit reached, send a termination wake signal (enforced)
 				select {
-				case d.wakeCh <- false:
+				case d.blockWakeCh <- false:
 				case <-d.cancelCh:
 				}
 				return nil
@@ -707,10 +793,8 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 
 	update := make(chan struct{}, 1)
 
-	// Prepare the queue and fetch blocks until the hash fetcher's done
-	d.queue.Prepare(from)
+	// Fetch blocks until the hash fetcher's done
 	finished := false
-
 	for {
 		select {
 		case <-d.cancelCh:
@@ -733,13 +817,13 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 					// If no blocks were delivered, demote the peer (need the delivery above)
 					if len(blockPack.blocks) == 0 {
 						peer.Demote()
-						peer.SetIdle61()
+						peer.SetBlocksIdle()
 						glog.V(logger.Detail).Infof("%s: no blocks delivered", peer)
 						break
 					}
 					// All was successful, promote the peer and potentially start processing
 					peer.Promote()
-					peer.SetIdle61()
+					peer.SetBlocksIdle()
 					glog.V(logger.Detail).Infof("%s: delivered %d blocks", peer, len(blockPack.blocks))
 					go d.process()
 
@@ -751,7 +835,7 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 					// Peer probably timed out with its delivery but came through
 					// in the end, demote, but allow to to pull from this peer.
 					peer.Demote()
-					peer.SetIdle61()
+					peer.SetBlocksIdle()
 					glog.V(logger.Detail).Infof("%s: out of bound delivery", peer)
 
 				case errStaleDelivery:
@@ -765,7 +849,7 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 				default:
 					// Peer did something semi-useful, demote but keep it around
 					peer.Demote()
-					peer.SetIdle61()
+					peer.SetBlocksIdle()
 					glog.V(logger.Detail).Infof("%s: delivery partially failed: %v", peer, err)
 					go d.process()
 				}
@@ -776,7 +860,7 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 			default:
 			}
 
-		case cont := <-d.wakeCh:
+		case cont := <-d.blockWakeCh:
 			// The hash fetcher sent a continuation flag, check if it's done
 			if !cont {
 				finished = true
@@ -800,14 +884,14 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 				return errNoPeers
 			}
 			// Check for block request timeouts and demote the responsible peers
-			for _, pid := range d.queue.Expire(blockHardTTL) {
+			for _, pid := range d.queue.Expire61(blockHardTTL) {
 				if peer := d.peers.Peer(pid); peer != nil {
 					peer.Demote()
 					glog.V(logger.Detail).Infof("%s: block delivery timeout", peer)
 				}
 			}
-			// If there's noting more to fetch, wait or terminate
-			if d.queue.Pending() == 0 {
+			// If there's nothing more to fetch, wait or terminate
+			if d.queue.PendingBlocks() == 0 {
 				if d.queue.InFlight() == 0 && finished {
 					glog.V(logger.Debug).Infof("Block fetching completed")
 					return nil
@@ -816,16 +900,18 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 			}
 			// Send a download request to all idle peers, until throttled
 			throttled := false
-			for _, peer := range d.peers.IdlePeers(eth61) {
+			idles, total := d.peers.BlockIdlePeers(61)
+
+			for _, peer := range idles {
 				// Short circuit if throttling activated
-				if d.queue.Throttle() {
+				if d.queue.ThrottleBlocks() {
 					throttled = true
 					break
 				}
 				// Reserve a chunk of hashes for a peer. A nil can mean either that
 				// no more hashes are available, or that the peer is known not to
 				// have them.
-				request := d.queue.Reserve61(peer, peer.Capacity())
+				request := d.queue.Reserve61(peer, peer.BlockCapacity())
 				if request == nil {
 					continue
 				}
@@ -835,12 +921,12 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 				// Fetch the chunk and make sure any errors return the hashes to the queue
 				if err := peer.Fetch61(request); err != nil {
 					glog.V(logger.Error).Infof("%v: fetch failed, rescheduling", peer)
-					d.queue.Cancel(request)
+					d.queue.Cancel61(request)
 				}
 			}
 			// Make sure that we have peers available for fetching. If all peers have been tried
 			// and all failed throw an error
-			if !throttled && d.queue.InFlight() == 0 {
+			if !throttled && d.queue.InFlight() == 0 && len(idles) == total {
 				return errPeersUnavailable
 			}
 		}
@@ -891,16 +977,19 @@ func (d *Downloader) fetchHeight(p *peer) (uint64, error) {
 	}
 }
 
-// findAncestor tries to locate the common ancestor block of the local chain and
+// findAncestor tries to locate the common ancestor link of the local chain and
 // a remote peers blockchain. In the general case when our node was in sync and
-// on the correct chain, checking the top N blocks should already get us a match.
+// on the correct chain, checking the top N links should already get us a match.
 // In the rare scenario when we ended up on a long reorganization (i.e. none of
-// the head blocks match), we do a binary search to find the common ancestor.
+// the head links match), we do a binary search to find the common ancestor.
 func (d *Downloader) findAncestor(p *peer) (uint64, error) {
 	glog.V(logger.Debug).Infof("%v: looking for common ancestor", p)
 
-	// Request our head blocks to short circuit ancestor location
-	head := d.headBlock().NumberU64()
+	// Request our head headers to short circuit ancestor location
+	head := d.headHeader().Number.Uint64()
+	if d.mode == FullSync {
+		head = d.headBlock().NumberU64()
+	}
 	from := int64(head) - int64(MaxHeaderFetch) + 1
 	if from < 0 {
 		from = 0
@@ -931,7 +1020,7 @@ func (d *Downloader) findAncestor(p *peer) (uint64, error) {
 			// Check if a common ancestor was found
 			finished = true
 			for i := len(headers) - 1; i >= 0; i-- {
-				if d.hasBlock(headers[i].Hash()) {
+				if (d.mode == FullSync && d.hasBlock(headers[i].Hash())) || (d.mode != FullSync && d.hasHeader(headers[i].Hash())) {
 					number, hash = headers[i].Number.Uint64(), headers[i].Hash()
 					break
 				}
@@ -986,13 +1075,13 @@ func (d *Downloader) findAncestor(p *peer) (uint64, error) {
 				arrived = true
 
 				// Modify the search interval based on the response
-				block := d.getBlock(headers[0].Hash())
-				if block == nil {
+				if (d.mode == FullSync && !d.hasBlock(headers[0].Hash())) || (d.mode != FullSync && !d.hasHeader(headers[0].Hash())) {
 					end = check
 					break
 				}
-				if block.NumberU64() != check {
-					glog.V(logger.Debug).Infof("%v: non requested header #%d [%x…], instead of #%d", p, block.NumberU64(), block.Hash().Bytes()[:4], check)
+				header := d.getHeader(headers[0].Hash()) // Independent of sync mode, header surely exists
+				if header.Number.Uint64() != check {
+					glog.V(logger.Debug).Infof("%v: non requested header #%d [%x…], instead of #%d", p, header.Number, header.Hash().Bytes()[:4], check)
 					return 0, errBadPeer
 				}
 				start = check
@@ -1017,6 +1106,9 @@ func (d *Downloader) findAncestor(p *peer) (uint64, error) {
 
 // fetchHeaders keeps retrieving headers from the requested number, until no more
 // are returned, potentially throttling on the way.
+//
+// The queue parameter can be used to switch between queuing headers for block
+// body download too, or directly import as pure header chains.
 func (d *Downloader) fetchHeaders(p *peer, td *big.Int, from uint64) error {
 	glog.V(logger.Debug).Infof("%v: downloading headers from #%d", p, from)
 	defer glog.V(logger.Debug).Infof("%v: header download terminated", p)
@@ -1058,13 +1150,15 @@ func (d *Downloader) fetchHeaders(p *peer, td *big.Int, from uint64) error {
 			headerReqTimer.UpdateSince(request)
 			timeout.Stop()
 
-			// If no more headers are inbound, notify the body fetcher and return
+			// If no more headers are inbound, notify the content fetchers and return
 			if len(headerPack.headers) == 0 {
 				glog.V(logger.Debug).Infof("%v: no available headers", p)
 
-				select {
-				case d.wakeCh <- false:
-				case <-d.cancelCh:
+				for _, ch := range []chan bool{d.bodyWakeCh, d.receiptWakeCh} {
+					select {
+					case ch <- false:
+					case <-d.cancelCh:
+					}
 				}
 				// If no headers were retrieved at all, the peer violated it's TD promise that it had a
 				// better chain compared to ours. The only exception is if it's promised blocks were
@@ -1086,27 +1180,37 @@ func (d *Downloader) fetchHeaders(p *peer, td *big.Int, from uint64) error {
 			gotHeaders = true
 
 			// Otherwise insert all the new headers, aborting in case of junk
-			glog.V(logger.Detail).Infof("%v: inserting %d headers from #%d", p, len(headerPack.headers), from)
+			glog.V(logger.Detail).Infof("%v: schedule %d headers from #%d", p, len(headerPack.headers), from)
 
-			inserts := d.queue.Insert(headerPack.headers, from)
-			if len(inserts) != len(headerPack.headers) {
-				glog.V(logger.Debug).Infof("%v: stale headers", p)
-				return errBadPeer
-			}
-			// Notify the block fetcher of new headers, but stop if queue is full
-			if d.queue.Pending() < maxQueuedHeaders {
-				// We still have headers to fetch, send continuation wake signal (potential)
-				select {
-				case d.wakeCh <- true:
-				default:
+			if d.mode == FullSync || d.mode == FastSync {
+				inserts := d.queue.Schedule(headerPack.headers, from, d.mode == FastSync)
+				if len(inserts) != len(headerPack.headers) {
+					glog.V(logger.Debug).Infof("%v: stale headers", p)
+					return errBadPeer
 				}
 			} else {
-				// Header limit reached, send a termination wake signal (enforced)
-				select {
-				case d.wakeCh <- false:
-				case <-d.cancelCh:
+				if n, err := d.insertHeaders(headerPack.headers, true); err != nil {
+					glog.V(logger.Debug).Infof("%v: invalid header #%d [%x…]: %v", p, headerPack.headers[n].Number, headerPack.headers[n].Hash().Bytes()[:4], err)
+					return errInvalidChain
+				}
+			}
+			// Notify the content fetchers of new headers, but stop if queue is full
+			cont := d.queue.PendingBlocks() < maxQueuedHeaders || d.queue.PendingReceipts() < maxQueuedHeaders
+			for _, ch := range []chan bool{d.bodyWakeCh, d.receiptWakeCh} {
+				if cont {
+					// We still have headers to fetch, send continuation wake signal (potential)
+					select {
+					case ch <- true:
+					default:
+					}
+				} else {
+					// Header limit reached, send a termination wake signal (enforced)
+					select {
+					case ch <- false:
+					case <-d.cancelCh:
+					}
+					return nil
 				}
-				return nil
 			}
 			// Queue not yet full, fetch the next batch
 			from += uint64(len(headerPack.headers))
@@ -1119,9 +1223,11 @@ func (d *Downloader) fetchHeaders(p *peer, td *big.Int, from uint64) error {
 			d.dropPeer(p.id)
 
 			// Finish the sync gracefully instead of dumping the gathered data though
-			select {
-			case d.wakeCh <- false:
-			case <-d.cancelCh:
+			for _, ch := range []chan bool{d.bodyWakeCh, d.receiptWakeCh} {
+				select {
+				case ch <- false:
+				case <-d.cancelCh:
+				}
 			}
 			return nil
 		}
@@ -1133,22 +1239,69 @@ func (d *Downloader) fetchHeaders(p *peer, td *big.Int, from uint64) error {
 // and also periodically checking for timeouts.
 func (d *Downloader) fetchBodies(from uint64) error {
 	glog.V(logger.Debug).Infof("Downloading block bodies from #%d", from)
-	defer glog.V(logger.Debug).Infof("Block body download terminated")
 
-	// Create a timeout timer for scheduling expiration tasks
+	var (
+		deliver = func(packet interface{}) error {
+			pack := packet.(*bodyPack)
+			return d.queue.DeliverBlocks(pack.peerId, pack.transactions, pack.uncles)
+		}
+		expire   = func() []string { return d.queue.ExpireBlocks(bodyHardTTL) }
+		fetch    = func(p *peer, req *fetchRequest) error { return p.FetchBodies(req) }
+		capacity = func(p *peer) int { return p.BlockCapacity() }
+		getIdles = func() ([]*peer, int) { return d.peers.BlockIdlePeers(62) }
+		setIdle  = func(p *peer) { p.SetBlocksIdle() }
+	)
+	err := d.fetchParts(from, errCancelBodyFetch, d.bodyCh, deliver, d.bodyWakeCh, expire,
+		d.queue.PendingBlocks, d.queue.ThrottleBlocks, d.queue.ReserveBlocks, d.bodyFetchHook,
+		fetch, d.queue.CancelBlocks, capacity, getIdles, setIdle, "Body")
+
+	glog.V(logger.Debug).Infof("Block body download terminated: %v", err)
+	return err
+}
+
+// fetchReceipts iteratively downloads the scheduled block receipts, taking any
+// available peers, reserving a chunk of receipts for each, waiting for delivery
+// and also periodically checking for timeouts.
+func (d *Downloader) fetchReceipts(from uint64) error {
+	glog.V(logger.Debug).Infof("Downloading receipts from #%d", from)
+
+	var (
+		deliver = func(packet interface{}) error {
+			pack := packet.(*receiptPack)
+			return d.queue.DeliverReceipts(pack.peerId, pack.receipts)
+		}
+		expire   = func() []string { return d.queue.ExpireReceipts(bodyHardTTL) }
+		fetch    = func(p *peer, req *fetchRequest) error { return p.FetchReceipts(req) }
+		capacity = func(p *peer) int { return p.ReceiptCapacity() }
+		setIdle  = func(p *peer) { p.SetReceiptsIdle() }
+	)
+	err := d.fetchParts(from, errCancelReceiptFetch, d.receiptCh, deliver, d.receiptWakeCh, expire,
+		d.queue.PendingReceipts, d.queue.ThrottleReceipts, d.queue.ReserveReceipts, d.receiptFetchHook,
+		fetch, d.queue.CancelReceipts, capacity, d.peers.ReceiptIdlePeers, setIdle, "Receipt")
+
+	glog.V(logger.Debug).Infof("Receipt download terminated: %v", err)
+	return err
+}
+
+// fetchParts iteratively downloads scheduled block parts, taking any available
+// peers, reserving a chunk of fetch requests for each, waiting for delivery and
+// also periodically checking for timeouts.
+func (d *Downloader) fetchParts(from uint64, errCancel error, deliveryCh chan dataPack, deliver func(packet interface{}) error, wakeCh chan bool,
+	expire func() []string, pending func() int, throttle func() bool, reserve func(*peer, int) (*fetchRequest, bool, error), fetchHook func([]*types.Header),
+	fetch func(*peer, *fetchRequest) error, cancel func(*fetchRequest), capacity func(*peer) int, idle func() ([]*peer, int), setIdle func(*peer), kind string) error {
+
+	// Create a ticker to detect expired retreival tasks
 	ticker := time.NewTicker(100 * time.Millisecond)
 	defer ticker.Stop()
 
 	update := make(chan struct{}, 1)
 
-	// Prepare the queue and fetch block bodies until the block header fetcher's done
-	d.queue.Prepare(from)
+	// Prepare the queue and fetch block parts until the block header fetcher's done
 	finished := false
-
 	for {
 		select {
 		case <-d.cancelCh:
-			return errCancelBlockFetch
+			return errCancel
 
 		case <-d.hashCh:
 			// Out of bounds eth/61 hashes received, ignore them
@@ -1156,42 +1309,41 @@ func (d *Downloader) fetchBodies(from uint64) error {
 		case <-d.blockCh:
 			// Out of bounds eth/61 blocks received, ignore them
 
-		case bodyPack := <-d.bodyCh:
+		case packet := <-deliveryCh:
 			// If the peer was previously banned and failed to deliver it's pack
 			// in a reasonable time frame, ignore it's message.
-			if peer := d.peers.Peer(bodyPack.peerId); peer != nil {
-				// Deliver the received chunk of bodies, and demote in case of errors
-				err := d.queue.Deliver(bodyPack.peerId, bodyPack.transactions, bodyPack.uncles)
-				switch err {
+			if peer := d.peers.Peer(packet.PeerId()); peer != nil {
+				// Deliver the received chunk of data, and demote in case of errors
+				switch err := deliver(packet); err {
 				case nil:
-					// If no blocks were delivered, demote the peer (need the delivery above)
-					if len(bodyPack.transactions) == 0 || len(bodyPack.uncles) == 0 {
+					// If no blocks were delivered, demote the peer (need the delivery above to clean internal queue!)
+					if packet.Empty() {
 						peer.Demote()
-						peer.SetIdle()
-						glog.V(logger.Detail).Infof("%s: no block bodies delivered", peer)
+						setIdle(peer)
+						glog.V(logger.Detail).Infof("%s: no %s delivered", peer, strings.ToLower(kind))
 						break
 					}
 					// All was successful, promote the peer and potentially start processing
 					peer.Promote()
-					peer.SetIdle()
-					glog.V(logger.Detail).Infof("%s: delivered %d:%d block bodies", peer, len(bodyPack.transactions), len(bodyPack.uncles))
+					setIdle(peer)
+					glog.V(logger.Detail).Infof("%s: delivered %s %s(s)", peer, packet.Stats(), strings.ToLower(kind))
 					go d.process()
 
 				case errInvalidChain:
 					// The hash chain is invalid (blocks are not ordered properly), abort
 					return err
 
-				case errInvalidBody:
+				case errInvalidBody, errInvalidReceipt:
 					// The peer delivered something very bad, drop immediately
-					glog.V(logger.Error).Infof("%s: delivered invalid block, dropping", peer)
+					glog.V(logger.Error).Infof("%s: delivered invalid %s, dropping", peer, strings.ToLower(kind))
 					d.dropPeer(peer.id)
 
 				case errNoFetchesPending:
 					// Peer probably timed out with its delivery but came through
 					// in the end, demote, but allow to to pull from this peer.
 					peer.Demote()
-					peer.SetIdle()
-					glog.V(logger.Detail).Infof("%s: out of bound delivery", peer)
+					setIdle(peer)
+					glog.V(logger.Detail).Infof("%s: out of bound %s delivery", peer, strings.ToLower(kind))
 
 				case errStaleDelivery:
 					// Delivered something completely else than requested, usually
@@ -1199,13 +1351,13 @@ func (d *Downloader) fetchBodies(from uint64) error {
 					// Don't set it to idle as the original request should still be
 					// in flight.
 					peer.Demote()
-					glog.V(logger.Detail).Infof("%s: stale delivery", peer)
+					glog.V(logger.Detail).Infof("%s: %s stale delivery", peer, strings.ToLower(kind))
 
 				default:
 					// Peer did something semi-useful, demote but keep it around
 					peer.Demote()
-					peer.SetIdle()
-					glog.V(logger.Detail).Infof("%s: delivery partially failed: %v", peer, err)
+					setIdle(peer)
+					glog.V(logger.Detail).Infof("%s: %s delivery partially failed: %v", peer, strings.ToLower(kind), err)
 					go d.process()
 				}
 			}
@@ -1215,7 +1367,7 @@ func (d *Downloader) fetchBodies(from uint64) error {
 			default:
 			}
 
-		case cont := <-d.wakeCh:
+		case cont := <-wakeCh:
 			// The header fetcher sent a continuation flag, check if it's done
 			if !cont {
 				finished = true
@@ -1238,65 +1390,69 @@ func (d *Downloader) fetchBodies(from uint64) error {
 			if d.peers.Len() == 0 {
 				return errNoPeers
 			}
-			// Check for block body request timeouts and demote the responsible peers
-			for _, pid := range d.queue.Expire(bodyHardTTL) {
+			// Check for fetch request timeouts and demote the responsible peers
+			for _, pid := range expire() {
 				if peer := d.peers.Peer(pid); peer != nil {
 					peer.Demote()
-					glog.V(logger.Detail).Infof("%s: block body delivery timeout", peer)
+					glog.V(logger.Detail).Infof("%s: %s delivery timeout", peer, strings.ToLower(kind))
 				}
 			}
-			// If there's noting more to fetch, wait or terminate
-			if d.queue.Pending() == 0 {
+			// If there's nothing more to fetch, wait or terminate
+			if pending() == 0 {
 				if d.queue.InFlight() == 0 && finished {
-					glog.V(logger.Debug).Infof("Block body fetching completed")
+					glog.V(logger.Debug).Infof("%s fetching completed", kind)
 					return nil
 				}
 				break
 			}
 			// Send a download request to all idle peers, until throttled
-			queuedEmptyBlocks, throttled := false, false
-			for _, peer := range d.peers.IdlePeers(eth62) {
+			progressed, throttled := false, false
+			idles, total := idle()
+
+			for _, peer := range idles {
 				// Short circuit if throttling activated
-				if d.queue.Throttle() {
+				if throttle() {
 					throttled = true
 					break
 				}
-				// Reserve a chunk of hashes for a peer. A nil can mean either that
-				// no more hashes are available, or that the peer is known not to
+				// Reserve a chunk of fetches for a peer. A nil can mean either that
+				// no more headers are available, or that the peer is known not to
 				// have them.
-				request, process, err := d.queue.Reserve(peer, peer.Capacity())
+				request, progress, err := reserve(peer, capacity(peer))
 				if err != nil {
 					return err
 				}
-				if process {
-					queuedEmptyBlocks = true
+				if progress {
+					progressed = true
 					go d.process()
 				}
 				if request == nil {
 					continue
 				}
 				if glog.V(logger.Detail) {
-					glog.Infof("%s: requesting %d block bodies", peer, len(request.Headers))
+					glog.Infof("%s: requesting %d %s(s), first at #%d", peer, len(request.Headers), strings.ToLower(kind), request.Headers[0].Number)
 				}
 				// Fetch the chunk and make sure any errors return the hashes to the queue
-				if d.bodyFetchHook != nil {
-					d.bodyFetchHook(request.Headers)
+				if fetchHook != nil {
+					fetchHook(request.Headers)
 				}
-				if err := peer.Fetch(request); err != nil {
-					glog.V(logger.Error).Infof("%v: fetch failed, rescheduling", peer)
-					d.queue.Cancel(request)
+				if err := fetch(peer, request); err != nil {
+					glog.V(logger.Error).Infof("%v: %s fetch failed, rescheduling", peer, strings.ToLower(kind))
+					cancel(request)
 				}
 			}
 			// Make sure that we have peers available for fetching. If all peers have been tried
 			// and all failed throw an error
-			if !queuedEmptyBlocks && !throttled && d.queue.InFlight() == 0 {
+			if !progressed && !throttled && d.queue.InFlight() == 0 && len(idles) == total {
 				return errPeersUnavailable
 			}
 		}
 	}
 }
 
-// process takes blocks from the queue and tries to import them into the chain.
+// process takes fetch results from the queue and tries to import them into the
+// chain. The type of import operation will depend on the result contents:
+//  -
 //
 // The algorithmic flow is as follows:
 //  - The `processing` flag is swapped to 1 to ensure singleton access
@@ -1317,10 +1473,10 @@ func (d *Downloader) process() {
 	}
 	// If the processor just exited, but there are freshly pending items, try to
 	// reenter. This is needed because the goroutine spinned up for processing
-	// the fresh blocks might have been rejected entry to to this present thread
+	// the fresh results might have been rejected entry to to this present thread
 	// not yet releasing the `processing` state.
 	defer func() {
-		if atomic.LoadInt32(&d.interrupt) == 0 && d.queue.GetHeadBlock() != nil {
+		if atomic.LoadInt32(&d.interrupt) == 0 && d.queue.GetHeadResult() != nil {
 			d.process()
 		}
 	}()
@@ -1328,38 +1484,64 @@ func (d *Downloader) process() {
 	// the import statistics to zero.
 	defer atomic.StoreInt32(&d.processing, 0)
 
-	// Repeat the processing as long as there are blocks to import
+	// Repeat the processing as long as there are results to process
 	for {
-		// Fetch the next batch of blocks
-		blocks := d.queue.TakeBlocks()
-		if len(blocks) == 0 {
+		// Fetch the next batch of results
+		results := d.queue.TakeResults()
+		if len(results) == 0 {
 			return
 		}
 		if d.chainInsertHook != nil {
-			d.chainInsertHook(blocks)
+			d.chainInsertHook(results)
 		}
 		// Actually import the blocks
-		glog.V(logger.Debug).Infof("Inserting chain with %d blocks (#%v - #%v)\n", len(blocks), blocks[0].RawBlock.Number(), blocks[len(blocks)-1].RawBlock.Number())
-		for len(blocks) != 0 {
+		if glog.V(logger.Debug) {
+			first, last := results[0].Header, results[len(results)-1].Header
+			glog.V(logger.Debug).Infof("Inserting chain with %d items (#%d [%x…] - #%d [%x…])", len(results), first.Number, first.Hash().Bytes()[:4], last.Number, last.Hash().Bytes()[:4])
+		}
+		for len(results) != 0 {
 			// Check for any termination requests
 			if atomic.LoadInt32(&d.interrupt) == 1 {
 				return
 			}
-			// Retrieve the first batch of blocks to insert
-			max := int(math.Min(float64(len(blocks)), float64(maxBlockProcess)))
-			raw := make(types.Blocks, 0, max)
-			for _, block := range blocks[:max] {
-				raw = append(raw, block.RawBlock)
+			// Retrieve the a batch of results to import
+			var (
+				headers  = make([]*types.Header, 0, maxResultsProcess)
+				blocks   = make([]*types.Block, 0, maxResultsProcess)
+				receipts = make([]types.Receipts, 0, maxResultsProcess)
+			)
+			items := int(math.Min(float64(len(results)), float64(maxResultsProcess)))
+			for _, result := range results[:items] {
+				switch {
+				case d.mode == FullSync:
+					blocks = append(blocks, types.NewBlockWithHeader(result.Header).WithBody(result.Transactions, result.Uncles))
+				case d.mode == FastSync:
+					blocks = append(blocks, types.NewBlockWithHeader(result.Header).WithBody(result.Transactions, result.Uncles))
+					receipts = append(receipts, result.Receipts)
+				case d.mode == LightSync:
+					headers = append(headers, result.Header)
+				}
+			}
+			// Try to process the results, aborting if there's an error
+			var (
+				err   error
+				index int
+			)
+			switch {
+			case d.mode == FullSync:
+				index, err = d.insertBlocks(blocks)
+			case d.mode == FastSync:
+				index, err = d.insertReceipts(blocks, receipts)
+			case d.mode == LightSync:
+				index, err = d.insertHeaders(headers, true)
 			}
-			// Try to inset the blocks, drop the originating peer if there's an error
-			index, err := d.insertChain(raw)
 			if err != nil {
-				glog.V(logger.Debug).Infof("Block #%d import failed: %v", raw[index].NumberU64(), err)
-				d.dropPeer(blocks[index].OriginPeer)
+				glog.V(logger.Debug).Infof("Result #%d [%x…] processing failed: %v", results[index].Header.Number, results[index].Header.Hash(), err)
 				d.cancel()
 				return
 			}
-			blocks = blocks[max:]
+			// Shift the results to the next batch
+			results = results[items:]
 		}
 	}
 }
@@ -1468,7 +1650,34 @@ func (d *Downloader) DeliverBodies(id string, transactions [][]*types.Transactio
 	d.cancelLock.RUnlock()
 
 	select {
-	case d.bodyCh <- bodyPack{id, transactions, uncles}:
+	case d.bodyCh <- &bodyPack{id, transactions, uncles}:
+		return nil
+
+	case <-cancel:
+		return errNoSyncActive
+	}
+}
+
+// DeliverReceipts injects a new batch of receipts received from a remote node.
+func (d *Downloader) DeliverReceipts(id string, receipts [][]*types.Receipt) (err error) {
+	// Update the delivery metrics for both good and failed deliveries
+	receiptInMeter.Mark(int64(len(receipts)))
+	defer func() {
+		if err != nil {
+			receiptDropMeter.Mark(int64(len(receipts)))
+		}
+	}()
+	// Make sure the downloader is active
+	if atomic.LoadInt32(&d.synchronising) == 0 {
+		return errNoSyncActive
+	}
+	// Deliver or abort if the sync is canceled while queuing
+	d.cancelLock.RLock()
+	cancel := d.cancelCh
+	d.cancelLock.RUnlock()
+
+	select {
+	case d.receiptCh <- &receiptPack{id, receipts}:
 		return nil
 
 	case <-cancel:

eth/downloader/downloader_test.go

@@ -45,7 +45,8 @@ var (
 // the returned hash chain is ordered head->parent. In addition, every 3rd block
 // contains a transaction and every 5th an uncle to allow testing correct block
 // reassembly.
-func makeChain(n int, seed byte, parent *types.Block) ([]common.Hash, map[common.Hash]*types.Block) {
+func makeChain(n int, seed byte, parent *types.Block) ([]common.Hash, map[common.Hash]*types.Header, map[common.Hash]*types.Block) {
+	// Generate the block chain
 	blocks := core.GenerateChain(parent, testdb, n, func(i int, block *core.BlockGen) {
 		block.SetCoinbase(common.Address{seed})
 
@@ -62,59 +63,80 @@ func makeChain(n int, seed byte, parent *types.Block) ([]common.Hash, map[common
 			block.AddUncle(&types.Header{ParentHash: block.PrevBlock(i - 1).Hash(), Number: big.NewInt(int64(i - 1))})
 		}
 	})
+	// Convert the block-chain into a hash-chain and header/block maps
 	hashes := make([]common.Hash, n+1)
 	hashes[len(hashes)-1] = parent.Hash()
+
+	headerm := make(map[common.Hash]*types.Header, n+1)
+	headerm[parent.Hash()] = parent.Header()
+
 	blockm := make(map[common.Hash]*types.Block, n+1)
 	blockm[parent.Hash()] = parent
+
 	for i, b := range blocks {
 		hashes[len(hashes)-i-2] = b.Hash()
+		headerm[b.Hash()] = b.Header()
 		blockm[b.Hash()] = b
 	}
-	return hashes, blockm
+	return hashes, headerm, blockm
 }
 
 // makeChainFork creates two chains of length n, such that h1[:f] and
 // h2[:f] are different but have a common suffix of length n-f.
-func makeChainFork(n, f int, parent *types.Block) (h1, h2 []common.Hash, b1, b2 map[common.Hash]*types.Block) {
-	// Create the common suffix.
-	h, b := makeChain(n-f, 0, parent)
-	// Create the forks.
-	h1, b1 = makeChain(f, 1, b[h[0]])
-	h1 = append(h1, h[1:]...)
-	h2, b2 = makeChain(f, 2, b[h[0]])
-	h2 = append(h2, h[1:]...)
-	for hash, block := range b {
-		b1[hash] = block
-		b2[hash] = block
-	}
-	return h1, h2, b1, b2
+func makeChainFork(n, f int, parent *types.Block) ([]common.Hash, []common.Hash, map[common.Hash]*types.Header, map[common.Hash]*types.Header, map[common.Hash]*types.Block, map[common.Hash]*types.Block) {
+	// Create the common suffix
+	hashes, headers, blocks := makeChain(n-f, 0, parent)
+
+	// Create the forks
+	hashes1, headers1, blocks1 := makeChain(f, 1, blocks[hashes[0]])
+	hashes1 = append(hashes1, hashes[1:]...)
+
+	hashes2, headers2, blocks2 := makeChain(f, 2, blocks[hashes[0]])
+	hashes2 = append(hashes2, hashes[1:]...)
+
+	for hash, header := range headers {
+		headers1[hash] = header
+		headers2[hash] = header
+	}
+	for hash, block := range blocks {
+		blocks1[hash] = block
+		blocks2[hash] = block
+	}
+	return hashes1, hashes2, headers1, headers2, blocks1, blocks2
 }
 
 // downloadTester is a test simulator for mocking out local block chain.
 type downloadTester struct {
 	downloader *Downloader
 
-	ownHashes    []common.Hash                           // Hash chain belonging to the tester
-	ownBlocks    map[common.Hash]*types.Block            // Blocks belonging to the tester
-	ownChainTd   map[common.Hash]*big.Int                // Total difficulties of the blocks in the local chain
-	peerHashes   map[string][]common.Hash                // Hash chain belonging to different test peers
-	peerBlocks   map[string]map[common.Hash]*types.Block // Blocks belonging to different test peers
-	peerChainTds map[string]map[common.Hash]*big.Int     // Total difficulties of the blocks in the peer chains
+	ownHashes    []common.Hash                            // Hash chain belonging to the tester
+	ownHeaders   map[common.Hash]*types.Header            // Headers belonging to the tester
+	ownBlocks    map[common.Hash]*types.Block             // Blocks belonging to the tester
+	ownReceipts  map[common.Hash]types.Receipts           // Receipts belonging to the tester
+	ownChainTd   map[common.Hash]*big.Int                 // Total difficulties of the blocks in the local chain
+	peerHashes   map[string][]common.Hash                 // Hash chain belonging to different test peers
+	peerHeaders  map[string]map[common.Hash]*types.Header // Headers belonging to different test peers
+	peerBlocks   map[string]map[common.Hash]*types.Block  // Blocks belonging to different test peers
+	peerChainTds map[string]map[common.Hash]*big.Int      // Total difficulties of the blocks in the peer chains
 
 	lock sync.RWMutex
 }
 
 // newTester creates a new downloader test mocker.
-func newTester() *downloadTester {
+func newTester(mode SyncMode) *downloadTester {
 	tester := &downloadTester{
 		ownHashes:    []common.Hash{genesis.Hash()},
+		ownHeaders:   map[common.Hash]*types.Header{genesis.Hash(): genesis.Header()},
 		ownBlocks:    map[common.Hash]*types.Block{genesis.Hash(): genesis},
+		ownReceipts:  map[common.Hash]types.Receipts{genesis.Hash(): genesis.Receipts()},
 		ownChainTd:   map[common.Hash]*big.Int{genesis.Hash(): genesis.Difficulty()},
 		peerHashes:   make(map[string][]common.Hash),
+		peerHeaders:  make(map[string]map[common.Hash]*types.Header),
 		peerBlocks:   make(map[string]map[common.Hash]*types.Block),
 		peerChainTds: make(map[string]map[common.Hash]*big.Int),
 	}
-	tester.downloader = New(new(event.TypeMux), tester.hasBlock, tester.getBlock, tester.headBlock, tester.getTd, tester.insertChain, tester.dropPeer)
+	tester.downloader = New(mode, new(event.TypeMux), tester.hasHeader, tester.hasBlock, tester.getHeader, tester.getBlock,
+		tester.headHeader, tester.headBlock, tester.getTd, tester.insertHeaders, tester.insertBlocks, tester.insertConfirmedBlocks, tester.dropPeer)
 
 	return tester
 }
@@ -135,8 +157,7 @@ func (dl *downloadTester) sync(id string, td *big.Int) error {
 	err := dl.downloader.synchronise(id, hash, td)
 	for {
 		// If the queue is empty and processing stopped, break
-		hashes, blocks := dl.downloader.queue.Size()
-		if hashes+blocks == 0 && atomic.LoadInt32(&dl.downloader.processing) == 0 {
+		if dl.downloader.queue.Idle() && atomic.LoadInt32(&dl.downloader.processing) == 0 {
 			break
 		}
 		// Otherwise sleep a bit and retry
@@ -145,12 +166,22 @@ func (dl *downloadTester) sync(id string, td *big.Int) error {
 	return err
 }
 
-// hasBlock checks if a block is pres	ent in the testers canonical chain.
+// hasHeader checks if a header is present in the testers canonical chain.
+func (dl *downloadTester) hasHeader(hash common.Hash) bool {
+	return dl.getHeader(hash) != nil
+}
+
+// hasBlock checks if a block is present in the testers canonical chain.
 func (dl *downloadTester) hasBlock(hash common.Hash) bool {
+	return dl.getBlock(hash) != nil
+}
+
+// getHeader retrieves a header from the testers canonical chain.
+func (dl *downloadTester) getHeader(hash common.Hash) *types.Header {
 	dl.lock.RLock()
 	defer dl.lock.RUnlock()
 
-	return dl.getBlock(hash) != nil
+	return dl.ownHeaders[hash]
 }
 
 // getBlock retrieves a block from the testers canonical chain.
@@ -161,12 +192,25 @@ func (dl *downloadTester) getBlock(hash common.Hash) *types.Block {
 	return dl.ownBlocks[hash]
 }
 
+// headHeader retrieves the current head header from the canonical chain.
+func (dl *downloadTester) headHeader() *types.Header {
+	dl.lock.RLock()
+	defer dl.lock.RUnlock()
+
+	return dl.getHeader(dl.ownHashes[len(dl.ownHashes)-1])
+}
+
 // headBlock retrieves the current head block from the canonical chain.
 func (dl *downloadTester) headBlock() *types.Block {
 	dl.lock.RLock()
 	defer dl.lock.RUnlock()
 
-	return dl.getBlock(dl.ownHashes[len(dl.ownHashes)-1])
+	for i := len(dl.ownHashes) - 1; i >= 0; i-- {
+		if block := dl.getBlock(dl.ownHashes[i]); block != nil {
+			return block
+		}
+	}
+	return nil
 }
 
 // getTd retrieves the block's total difficulty from the canonical chain.
@@ -177,8 +221,24 @@ func (dl *downloadTester) getTd(hash common.Hash) *big.Int {
 	return dl.ownChainTd[hash]
 }
 
-// insertChain injects a new batch of blocks into the simulated chain.
-func (dl *downloadTester) insertChain(blocks types.Blocks) (int, error) {
+// insertHeaders injects a new batch of headers into the simulated chain.
+func (dl *downloadTester) insertHeaders(headers []*types.Header, verify bool) (int, error) {
+	dl.lock.Lock()
+	defer dl.lock.Unlock()
+
+	for i, header := range headers {
+		if _, ok := dl.ownHeaders[header.ParentHash]; !ok {
+			return i, errors.New("unknown parent")
+		}
+		dl.ownHashes = append(dl.ownHashes, header.Hash())
+		dl.ownHeaders[header.Hash()] = header
+		dl.ownChainTd[header.Hash()] = dl.ownChainTd[header.ParentHash]
+	}
+	return len(headers), nil
+}
+
+// insertBlocks injects a new batch of blocks into the simulated chain.
+func (dl *downloadTester) insertBlocks(blocks types.Blocks) (int, error) {
 	dl.lock.Lock()
 	defer dl.lock.Unlock()
 
@@ -187,47 +247,74 @@ func (dl *downloadTester) insertChain(blocks types.Blocks) (int, error) {
 			return i, errors.New("unknown parent")
 		}
 		dl.ownHashes = append(dl.ownHashes, block.Hash())
+		dl.ownHeaders[block.Hash()] = block.Header()
 		dl.ownBlocks[block.Hash()] = block
 		dl.ownChainTd[block.Hash()] = dl.ownChainTd[block.ParentHash()]
 	}
 	return len(blocks), nil
 }
 
+// insertBlocks injects a new batch of blocks into the simulated chain.
+func (dl *downloadTester) insertConfirmedBlocks(blocks types.Blocks, receipts []types.Receipts) (int, error) {
+	dl.lock.Lock()
+	defer dl.lock.Unlock()
+
+	for i := 0; i < len(blocks) && i < len(receipts); i++ {
+		if _, ok := dl.ownBlocks[blocks[i].ParentHash()]; !ok {
+			return i, errors.New("unknown parent")
+		}
+		dl.ownHashes = append(dl.ownHashes, blocks[i].Hash())
+		dl.ownHeaders[blocks[i].Hash()] = blocks[i].Header()
+		dl.ownBlocks[blocks[i].Hash()] = blocks[i]
+		dl.ownReceipts[blocks[i].Hash()] = blocks[i].Receipts()
+		dl.ownChainTd[blocks[i].Hash()] = dl.ownChainTd[blocks[i].ParentHash()]
+	}
+	return len(blocks), nil
+}
+
 // newPeer registers a new block download source into the downloader.
-func (dl *downloadTester) newPeer(id string, version int, hashes []common.Hash, blocks map[common.Hash]*types.Block) error {
-	return dl.newSlowPeer(id, version, hashes, blocks, 0)
+func (dl *downloadTester) newPeer(id string, version int, hashes []common.Hash, headers map[common.Hash]*types.Header, blocks map[common.Hash]*types.Block) error {
+	return dl.newSlowPeer(id, version, hashes, headers, blocks, 0)
 }
 
 // newSlowPeer registers a new block download source into the downloader, with a
 // specific delay time on processing the network packets sent to it, simulating
 // potentially slow network IO.
-func (dl *downloadTester) newSlowPeer(id string, version int, hashes []common.Hash, blocks map[common.Hash]*types.Block, delay time.Duration) error {
+func (dl *downloadTester) newSlowPeer(id string, version int, hashes []common.Hash, headers map[common.Hash]*types.Header, blocks map[common.Hash]*types.Block, delay time.Duration) error {
 	dl.lock.Lock()
 	defer dl.lock.Unlock()
 
 	var err error
 	switch version {
 	case 61:
-		err = dl.downloader.RegisterPeer(id, version, hashes[0], dl.peerGetRelHashesFn(id, delay), dl.peerGetAbsHashesFn(id, delay), dl.peerGetBlocksFn(id, delay), nil, nil, nil)
+		err = dl.downloader.RegisterPeer(id, version, hashes[0], dl.peerGetRelHashesFn(id, delay), dl.peerGetAbsHashesFn(id, delay), dl.peerGetBlocksFn(id, delay), nil, nil, nil, nil)
 	case 62:
-		err = dl.downloader.RegisterPeer(id, version, hashes[0], nil, nil, nil, dl.peerGetRelHeadersFn(id, delay), dl.peerGetAbsHeadersFn(id, delay), dl.peerGetBodiesFn(id, delay))
+		err = dl.downloader.RegisterPeer(id, version, hashes[0], nil, nil, nil, dl.peerGetRelHeadersFn(id, delay), dl.peerGetAbsHeadersFn(id, delay), dl.peerGetBodiesFn(id, delay), nil)
 	case 63:
-		err = dl.downloader.RegisterPeer(id, version, hashes[0], nil, nil, nil, dl.peerGetRelHeadersFn(id, delay), dl.peerGetAbsHeadersFn(id, delay), dl.peerGetBodiesFn(id, delay))
+		err = dl.downloader.RegisterPeer(id, version, hashes[0], nil, nil, nil, dl.peerGetRelHeadersFn(id, delay), dl.peerGetAbsHeadersFn(id, delay), dl.peerGetBodiesFn(id, delay), dl.peerGetReceiptsFn(id, delay))
 	case 64:
-		err = dl.downloader.RegisterPeer(id, version, hashes[0], nil, nil, nil, dl.peerGetRelHeadersFn(id, delay), dl.peerGetAbsHeadersFn(id, delay), dl.peerGetBodiesFn(id, delay))
+		err = dl.downloader.RegisterPeer(id, version, hashes[0], nil, nil, nil, dl.peerGetRelHeadersFn(id, delay), dl.peerGetAbsHeadersFn(id, delay), dl.peerGetBodiesFn(id, delay), dl.peerGetReceiptsFn(id, delay))
 	}
 	if err == nil {
-		// Assign the owned hashes and blocks to the peer (deep copy)
+		// Assign the owned hashes, headers and blocks to the peer (deep copy)
 		dl.peerHashes[id] = make([]common.Hash, len(hashes))
 		copy(dl.peerHashes[id], hashes)
 
+		dl.peerHeaders[id] = make(map[common.Hash]*types.Header)
 		dl.peerBlocks[id] = make(map[common.Hash]*types.Block)
 		dl.peerChainTds[id] = make(map[common.Hash]*big.Int)
+
 		for _, hash := range hashes {
+			if header, ok := headers[hash]; ok {
+				dl.peerHeaders[id][hash] = header
+				if _, ok := dl.peerHeaders[id][header.ParentHash]; ok {
+					dl.peerChainTds[id][hash] = new(big.Int).Add(header.Difficulty, dl.peerChainTds[id][header.ParentHash])
+				}
+			}
 			if block, ok := blocks[hash]; ok {
 				dl.peerBlocks[id][hash] = block
-				if parent, ok := dl.peerBlocks[id][block.ParentHash()]; ok {
-					dl.peerChainTds[id][hash] = new(big.Int).Add(block.Difficulty(), dl.peerChainTds[id][parent.Hash()])
+				if _, ok := dl.peerBlocks[id][block.ParentHash()]; ok {
+					dl.peerChainTds[id][hash] = new(big.Int).Add(block.Difficulty(), dl.peerChainTds[id][block.ParentHash()])
 				}
 			}
 		}
@@ -241,6 +328,7 @@ func (dl *downloadTester) dropPeer(id string) {
 	defer dl.lock.Unlock()
 
 	delete(dl.peerHashes, id)
+	delete(dl.peerHeaders, id)
 	delete(dl.peerBlocks, id)
 	delete(dl.peerChainTds, id)
 
@@ -358,13 +446,13 @@ func (dl *downloadTester) peerGetAbsHeadersFn(id string, delay time.Duration) fu
 		dl.lock.RLock()
 		defer dl.lock.RUnlock()
 
-		// Gather the next batch of hashes
+		// Gather the next batch of headers
 		hashes := dl.peerHashes[id]
-		blocks := dl.peerBlocks[id]
+		headers := dl.peerHeaders[id]
 		result := make([]*types.Header, 0, amount)
 		for i := 0; i < amount && len(hashes)-int(origin)-1-i >= 0; i++ {
-			if block, ok := blocks[hashes[len(hashes)-int(origin)-1-i]]; ok {
-				result = append(result, block.Header())
+			if header, ok := headers[hashes[len(hashes)-int(origin)-1-i]]; ok {
+				result = append(result, header)
 			}
 		}
 		// Delay delivery a bit to allow attacks to unfold
@@ -403,50 +491,99 @@ func (dl *downloadTester) peerGetBodiesFn(id string, delay time.Duration) func([
 	}
 }
 
+// peerGetReceiptsFn constructs a getReceipts method associated with a particular
+// peer in the download tester. The returned function can be used to retrieve
+// batches of block receipts from the particularly requested peer.
+func (dl *downloadTester) peerGetReceiptsFn(id string, delay time.Duration) func([]common.Hash) error {
+	return func(hashes []common.Hash) error {
+		time.Sleep(delay)
+
+		dl.lock.RLock()
+		defer dl.lock.RUnlock()
+
+		blocks := dl.peerBlocks[id]
+
+		receipts := make([][]*types.Receipt, 0, len(hashes))
+		for _, hash := range hashes {
+			if block, ok := blocks[hash]; ok {
+				receipts = append(receipts, block.Receipts())
+			}
+		}
+		go dl.downloader.DeliverReceipts(id, receipts)
+
+		return nil
+	}
+}
+
+// assertOwnChain checks if the local chain contains the correct number of items
+// of the various chain components.
+func assertOwnChain(t *testing.T, tester *downloadTester, length int) {
+	headers, blocks, receipts := length, length, length
+	switch tester.downloader.mode {
+	case FullSync:
+		receipts = 1
+	case LightSync:
+		blocks, receipts = 1, 1
+	}
+
+	if hs := len(tester.ownHeaders); hs != headers {
+		t.Fatalf("synchronised headers mismatch: have %v, want %v", hs, headers)
+	}
+	if bs := len(tester.ownBlocks); bs != blocks {
+		t.Fatalf("synchronised blocks mismatch: have %v, want %v", bs, blocks)
+	}
+	if rs := len(tester.ownReceipts); rs != receipts {
+		t.Fatalf("synchronised receipts mismatch: have %v, want %v", rs, receipts)
+	}
+}
+
 // Tests that simple synchronization against a canonical chain works correctly.
 // In this test common ancestor lookup should be short circuited and not require
 // binary searching.
-func TestCanonicalSynchronisation61(t *testing.T) { testCanonicalSynchronisation(t, 61) }
-func TestCanonicalSynchronisation62(t *testing.T) { testCanonicalSynchronisation(t, 62) }
-func TestCanonicalSynchronisation63(t *testing.T) { testCanonicalSynchronisation(t, 63) }
-func TestCanonicalSynchronisation64(t *testing.T) { testCanonicalSynchronisation(t, 64) }
-
-func testCanonicalSynchronisation(t *testing.T, protocol int) {
+func TestCanonicalSynchronisation61(t *testing.T)      { testCanonicalSynchronisation(t, 61, FullSync) }
+func TestCanonicalSynchronisation62(t *testing.T)      { testCanonicalSynchronisation(t, 62, FullSync) }
+func TestCanonicalSynchronisation63Full(t *testing.T)  { testCanonicalSynchronisation(t, 63, FullSync) }
+func TestCanonicalSynchronisation63Fast(t *testing.T)  { testCanonicalSynchronisation(t, 63, FastSync) }
+func TestCanonicalSynchronisation64Full(t *testing.T)  { testCanonicalSynchronisation(t, 64, FullSync) }
+func TestCanonicalSynchronisation64Fast(t *testing.T)  { testCanonicalSynchronisation(t, 64, FastSync) }
+func TestCanonicalSynchronisation64Light(t *testing.T) { testCanonicalSynchronisation(t, 64, LightSync) }
+
+func testCanonicalSynchronisation(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
-	tester := newTester()
-	tester.newPeer("peer", protocol, hashes, blocks)
+	tester := newTester(mode)
+	tester.newPeer("peer", protocol, hashes, headers, blocks)
 
-	// Synchronise with the peer and make sure all blocks were retrieved
+	// Synchronise with the peer and make sure all relevant data was retrieved
 	if err := tester.sync("peer", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, targetBlocks+1)
-	}
+	assertOwnChain(t, tester, targetBlocks+1)
 }
 
 // Tests that if a large batch of blocks are being downloaded, it is throttled
 // until the cached blocks are retrieved.
-func TestThrottling61(t *testing.T) { testThrottling(t, 61) }
-func TestThrottling62(t *testing.T) { testThrottling(t, 62) }
-func TestThrottling63(t *testing.T) { testThrottling(t, 63) }
-func TestThrottling64(t *testing.T) { testThrottling(t, 64) }
-
-func testThrottling(t *testing.T, protocol int) {
+func TestThrottling61(t *testing.T)     { testThrottling(t, 61, FullSync) }
+func TestThrottling62(t *testing.T)     { testThrottling(t, 62, FullSync) }
+func TestThrottling63Full(t *testing.T) { testThrottling(t, 63, FullSync) }
+func TestThrottling63Fast(t *testing.T) { testThrottling(t, 63, FastSync) }
+func TestThrottling64Full(t *testing.T) { testThrottling(t, 64, FullSync) }
+func TestThrottling64Fast(t *testing.T) { testThrottling(t, 64, FastSync) }
+
+func testThrottling(t *testing.T, protocol int, mode SyncMode) {
 	// Create a long block chain to download and the tester
 	targetBlocks := 8 * blockCacheLimit
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
-	tester := newTester()
-	tester.newPeer("peer", protocol, hashes, blocks)
+	tester := newTester(mode)
+	tester.newPeer("peer", protocol, hashes, headers, blocks)
 
 	// Wrap the importer to allow stepping
 	blocked, proceed := uint32(0), make(chan struct{})
-	tester.downloader.chainInsertHook = func(blocks []*Block) {
-		atomic.StoreUint32(&blocked, uint32(len(blocks)))
+	tester.downloader.chainInsertHook = func(results []*fetchResult) {
+		atomic.StoreUint32(&blocked, uint32(len(results)))
 		<-proceed
 	}
 	// Start a synchronisation concurrently
@@ -469,7 +606,12 @@ func testThrottling(t *testing.T, protocol int) {
 			time.Sleep(25 * time.Millisecond)
 
 			tester.downloader.queue.lock.RLock()
-			cached = len(tester.downloader.queue.blockPool)
+			cached = len(tester.downloader.queue.blockDonePool)
+			if mode == FastSync {
+				if receipts := len(tester.downloader.queue.receiptDonePool); receipts < cached {
+					cached = receipts
+				}
+			}
 			tester.downloader.queue.lock.RUnlock()
 
 			if cached == blockCacheLimit || len(tester.ownBlocks)+cached+int(atomic.LoadUint32(&blocked)) == targetBlocks+1 {
@@ -488,9 +630,7 @@ func testThrottling(t *testing.T, protocol int) {
 		}
 	}
 	// Check that we haven't pulled more blocks than available
-	if len(tester.ownBlocks) > targetBlocks+1 {
-		t.Fatalf("target block count mismatch: have %v, want %v", len(tester.ownBlocks), targetBlocks+1)
-	}
+	assertOwnChain(t, tester, targetBlocks+1)
 	if err := <-errc; err != nil {
 		t.Fatalf("block synchronization failed: %v", err)
 	}
@@ -499,39 +639,39 @@ func testThrottling(t *testing.T, protocol int) {
 // Tests that simple synchronization against a forked chain works correctly. In
 // this test common ancestor lookup should *not* be short circuited, and a full
 // binary search should be executed.
-func TestForkedSynchronisation61(t *testing.T) { testForkedSynchronisation(t, 61) }
-func TestForkedSynchronisation62(t *testing.T) { testForkedSynchronisation(t, 62) }
-func TestForkedSynchronisation63(t *testing.T) { testForkedSynchronisation(t, 63) }
-func TestForkedSynchronisation64(t *testing.T) { testForkedSynchronisation(t, 64) }
-
-func testForkedSynchronisation(t *testing.T, protocol int) {
+func TestForkedSynchronisation61(t *testing.T)      { testForkedSynchronisation(t, 61, FullSync) }
+func TestForkedSynchronisation62(t *testing.T)      { testForkedSynchronisation(t, 62, FullSync) }
+func TestForkedSynchronisation63Full(t *testing.T)  { testForkedSynchronisation(t, 63, FullSync) }
+func TestForkedSynchronisation63Fast(t *testing.T)  { testForkedSynchronisation(t, 63, FastSync) }
+func TestForkedSynchronisation64Full(t *testing.T)  { testForkedSynchronisation(t, 64, FullSync) }
+func TestForkedSynchronisation64Fast(t *testing.T)  { testForkedSynchronisation(t, 64, FastSync) }
+func TestForkedSynchronisation64Light(t *testing.T) { testForkedSynchronisation(t, 64, LightSync) }
+
+func testForkedSynchronisation(t *testing.T, protocol int, mode SyncMode) {
 	// Create a long enough forked chain
 	common, fork := MaxHashFetch, 2*MaxHashFetch
-	hashesA, hashesB, blocksA, blocksB := makeChainFork(common+fork, fork, genesis)
+	hashesA, hashesB, headersA, headersB, blocksA, blocksB := makeChainFork(common+fork, fork, genesis)
 
-	tester := newTester()
-	tester.newPeer("fork A", protocol, hashesA, blocksA)
-	tester.newPeer("fork B", protocol, hashesB, blocksB)
+	tester := newTester(mode)
+	tester.newPeer("fork A", protocol, hashesA, headersA, blocksA)
+	tester.newPeer("fork B", protocol, hashesB, headersB, blocksB)
 
 	// Synchronise with the peer and make sure all blocks were retrieved
 	if err := tester.sync("fork A", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != common+fork+1 {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, common+fork+1)
-	}
+	assertOwnChain(t, tester, common+fork+1)
+
 	// Synchronise with the second peer and make sure that fork is pulled too
 	if err := tester.sync("fork B", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != common+2*fork+1 {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, common+2*fork+1)
-	}
+	assertOwnChain(t, tester, common+2*fork+1)
 }
 
 // Tests that an inactive downloader will not accept incoming hashes and blocks.
 func TestInactiveDownloader61(t *testing.T) {
-	tester := newTester()
+	tester := newTester(FullSync)
 
 	// Check that neither hashes nor blocks are accepted
 	if err := tester.downloader.DeliverHashes61("bad peer", []common.Hash{}); err != errNoSyncActive {
@@ -542,9 +682,10 @@ func TestInactiveDownloader61(t *testing.T) {
 	}
 }
 
-// Tests that an inactive downloader will not accept incoming block headers and bodies.
+// Tests that an inactive downloader will not accept incoming block headers and
+// bodies.
 func TestInactiveDownloader62(t *testing.T) {
-	tester := newTester()
+	tester := newTester(FullSync)
 
 	// Check that neither block headers nor bodies are accepted
 	if err := tester.downloader.DeliverHeaders("bad peer", []*types.Header{}); err != errNoSyncActive {
@@ -555,13 +696,33 @@ func TestInactiveDownloader62(t *testing.T) {
 	}
 }
 
-// Tests that a canceled download wipes all previously accumulated state.
-func TestCancel61(t *testing.T) { testCancel(t, 61) }
-func TestCancel62(t *testing.T) { testCancel(t, 62) }
-func TestCancel63(t *testing.T) { testCancel(t, 63) }
-func TestCancel64(t *testing.T) { testCancel(t, 64) }
+// Tests that an inactive downloader will not accept incoming block headers,
+// bodies and receipts.
+func TestInactiveDownloader63(t *testing.T) {
+	tester := newTester(FullSync)
+
+	// Check that neither block headers nor bodies are accepted
+	if err := tester.downloader.DeliverHeaders("bad peer", []*types.Header{}); err != errNoSyncActive {
+		t.Errorf("error mismatch: have %v, want %v", err, errNoSyncActive)
+	}
+	if err := tester.downloader.DeliverBodies("bad peer", [][]*types.Transaction{}, [][]*types.Header{}); err != errNoSyncActive {
+		t.Errorf("error mismatch: have %v, want %v", err, errNoSyncActive)
+	}
+	if err := tester.downloader.DeliverReceipts("bad peer", [][]*types.Receipt{}); err != errNoSyncActive {
+		t.Errorf("error mismatch: have %v, want %v", err, errNoSyncActive)
+	}
+}
 
-func testCancel(t *testing.T, protocol int) {
+// Tests that a canceled download wipes all previously accumulated state.
+func TestCancel61(t *testing.T)      { testCancel(t, 61, FullSync) }
+func TestCancel62(t *testing.T)      { testCancel(t, 62, FullSync) }
+func TestCancel63Full(t *testing.T)  { testCancel(t, 63, FullSync) }
+func TestCancel63Fast(t *testing.T)  { testCancel(t, 63, FastSync) }
+func TestCancel64Full(t *testing.T)  { testCancel(t, 64, FullSync) }
+func TestCancel64Fast(t *testing.T)  { testCancel(t, 64, FastSync) }
+func TestCancel64Light(t *testing.T) { testCancel(t, 64, LightSync) }
+
+func testCancel(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download and the tester
 	targetBlocks := blockCacheLimit - 15
 	if targetBlocks >= MaxHashFetch {
@@ -570,80 +731,81 @@ func testCancel(t *testing.T, protocol int) {
 	if targetBlocks >= MaxHeaderFetch {
 		targetBlocks = MaxHeaderFetch - 15
 	}
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
-	tester := newTester()
-	tester.newPeer("peer", protocol, hashes, blocks)
+	tester := newTester(mode)
+	tester.newPeer("peer", protocol, hashes, headers, blocks)
 
 	// Make sure canceling works with a pristine downloader
 	tester.downloader.cancel()
-	downloading, importing := tester.downloader.queue.Size()
-	if downloading > 0 || importing > 0 {
-		t.Errorf("download or import count mismatch: %d downloading, %d importing, want 0", downloading, importing)
+	if !tester.downloader.queue.Idle() {
+		t.Errorf("download queue not idle")
 	}
 	// Synchronise with the peer, but cancel afterwards
 	if err := tester.sync("peer", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
 	tester.downloader.cancel()
-	downloading, importing = tester.downloader.queue.Size()
-	if downloading > 0 || importing > 0 {
-		t.Errorf("download or import count mismatch: %d downloading, %d importing, want 0", downloading, importing)
+	if !tester.downloader.queue.Idle() {
+		t.Errorf("download queue not idle")
 	}
 }
 
 // Tests that synchronisation from multiple peers works as intended (multi thread sanity test).
-func TestMultiSynchronisation61(t *testing.T) { testMultiSynchronisation(t, 61) }
-func TestMultiSynchronisation62(t *testing.T) { testMultiSynchronisation(t, 62) }
-func TestMultiSynchronisation63(t *testing.T) { testMultiSynchronisation(t, 63) }
-func TestMultiSynchronisation64(t *testing.T) { testMultiSynchronisation(t, 64) }
-
-func testMultiSynchronisation(t *testing.T, protocol int) {
+func TestMultiSynchronisation61(t *testing.T)      { testMultiSynchronisation(t, 61, FullSync) }
+func TestMultiSynchronisation62(t *testing.T)      { testMultiSynchronisation(t, 62, FullSync) }
+func TestMultiSynchronisation63Full(t *testing.T)  { testMultiSynchronisation(t, 63, FullSync) }
+func TestMultiSynchronisation63Fast(t *testing.T)  { testMultiSynchronisation(t, 63, FastSync) }
+func TestMultiSynchronisation64Full(t *testing.T)  { testMultiSynchronisation(t, 64, FullSync) }
+func TestMultiSynchronisation64Fast(t *testing.T)  { testMultiSynchronisation(t, 64, FastSync) }
+func TestMultiSynchronisation64Light(t *testing.T) { testMultiSynchronisation(t, 64, LightSync) }
+
+func testMultiSynchronisation(t *testing.T, protocol int, mode SyncMode) {
 	// Create various peers with various parts of the chain
 	targetPeers := 8
 	targetBlocks := targetPeers*blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
-	tester := newTester()
+	tester := newTester(mode)
 	for i := 0; i < targetPeers; i++ {
 		id := fmt.Sprintf("peer #%d", i)
-		tester.newPeer(id, protocol, hashes[i*blockCacheLimit:], blocks)
+		tester.newPeer(id, protocol, hashes[i*blockCacheLimit:], headers, blocks)
 	}
 	// Synchronise with the middle peer and make sure half of the blocks were retrieved
 	id := fmt.Sprintf("peer #%d", targetPeers/2)
 	if err := tester.sync(id, nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != len(tester.peerHashes[id]) {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, len(tester.peerHashes[id]))
-	}
+	assertOwnChain(t, tester, len(tester.peerHashes[id]))
+
 	// Synchronise with the best peer and make sure everything is retrieved
 	if err := tester.sync("peer #0", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, targetBlocks+1)
-	}
+	assertOwnChain(t, tester, targetBlocks+1)
 }
 
 // Tests that synchronisations behave well in multi-version protocol environments
 // and not wreak havok on other nodes in the network.
-func TestMultiProtocolSynchronisation61(t *testing.T) { testMultiProtocolSynchronisation(t, 61) }
-func TestMultiProtocolSynchronisation62(t *testing.T) { testMultiProtocolSynchronisation(t, 62) }
-func TestMultiProtocolSynchronisation63(t *testing.T) { testMultiProtocolSynchronisation(t, 63) }
-func TestMultiProtocolSynchronisation64(t *testing.T) { testMultiProtocolSynchronisation(t, 64) }
-
-func testMultiProtocolSynchronisation(t *testing.T, protocol int) {
+func TestMultiProtoSynchronisation61(t *testing.T)      { testMultiProtoSync(t, 61, FullSync) }
+func TestMultiProtoSynchronisation62(t *testing.T)      { testMultiProtoSync(t, 62, FullSync) }
+func TestMultiProtoSynchronisation63Full(t *testing.T)  { testMultiProtoSync(t, 63, FullSync) }
+func TestMultiProtoSynchronisation63Fast(t *testing.T)  { testMultiProtoSync(t, 63, FastSync) }
+func TestMultiProtoSynchronisation64Full(t *testing.T)  { testMultiProtoSync(t, 64, FullSync) }
+func TestMultiProtoSynchronisation64Fast(t *testing.T)  { testMultiProtoSync(t, 64, FastSync) }
+func TestMultiProtoSynchronisation64Light(t *testing.T) { testMultiProtoSync(t, 64, LightSync) }
+
+func testMultiProtoSync(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
 	// Create peers of every type
-	tester := newTester()
-	tester.newPeer("peer 61", 61, hashes, blocks)
-	tester.newPeer("peer 62", 62, hashes, blocks)
-	tester.newPeer("peer 63", 63, hashes, blocks)
-	tester.newPeer("peer 64", 64, hashes, blocks)
+	tester := newTester(mode)
+	tester.newPeer("peer 61", 61, hashes, headers, blocks)
+	tester.newPeer("peer 62", 62, hashes, headers, blocks)
+	tester.newPeer("peer 63", 63, hashes, headers, blocks)
+	tester.newPeer("peer 64", 64, hashes, headers, blocks)
 
 	// Synchronise with the requestd peer and make sure all blocks were retrieved
 	if err := tester.sync(fmt.Sprintf("peer %d", protocol), nil); err != nil {
@@ -661,150 +823,181 @@ func testMultiProtocolSynchronisation(t *testing.T, protocol int) {
 	}
 }
 
-// Tests that if a block is empty (i.e. header only), no body request should be
+// Tests that if a block is empty (e.g. header only), no body request should be
 // made, and instead the header should be assembled into a whole block in itself.
-func TestEmptyBlockShortCircuit62(t *testing.T) { testEmptyBlockShortCircuit(t, 62) }
-func TestEmptyBlockShortCircuit63(t *testing.T) { testEmptyBlockShortCircuit(t, 63) }
-func TestEmptyBlockShortCircuit64(t *testing.T) { testEmptyBlockShortCircuit(t, 64) }
-
-func testEmptyBlockShortCircuit(t *testing.T, protocol int) {
+func TestEmptyShortCircuit62(t *testing.T)      { testEmptyShortCircuit(t, 62, FullSync) }
+func TestEmptyShortCircuit63Full(t *testing.T)  { testEmptyShortCircuit(t, 63, FullSync) }
+func TestEmptyShortCircuit63Fast(t *testing.T)  { testEmptyShortCircuit(t, 63, FastSync) }
+func TestEmptyShortCircuit64Full(t *testing.T)  { testEmptyShortCircuit(t, 64, FullSync) }
+func TestEmptyShortCircuit64Fast(t *testing.T)  { testEmptyShortCircuit(t, 64, FastSync) }
+func TestEmptyShortCircuit64Light(t *testing.T) { testEmptyShortCircuit(t, 64, LightSync) }
+
+func testEmptyShortCircuit(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
-	tester := newTester()
-	tester.newPeer("peer", protocol, hashes, blocks)
+	tester := newTester(mode)
+	tester.newPeer("peer", protocol, hashes, headers, blocks)
 
 	// Instrument the downloader to signal body requests
-	requested := int32(0)
+	bodies, receipts := int32(0), int32(0)
 	tester.downloader.bodyFetchHook = func(headers []*types.Header) {
-		atomic.AddInt32(&requested, int32(len(headers)))
+		atomic.AddInt32(&bodies, int32(len(headers)))
+	}
+	tester.downloader.receiptFetchHook = func(headers []*types.Header) {
+		atomic.AddInt32(&receipts, int32(len(headers)))
 	}
 	// Synchronise with the peer and make sure all blocks were retrieved
 	if err := tester.sync("peer", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, targetBlocks+1)
-	}
+	assertOwnChain(t, tester, targetBlocks+1)
+
 	// Validate the number of block bodies that should have been requested
-	needed := 0
+	bodiesNeeded, receiptsNeeded := 0, 0
 	for _, block := range blocks {
-		if block != genesis && (len(block.Transactions()) > 0 || len(block.Uncles()) > 0) {
-			needed++
+		if mode != LightSync && block != genesis && (len(block.Transactions()) > 0 || len(block.Uncles()) > 0) {
+			bodiesNeeded++
 		}
+		if mode == FastSync && block != genesis && len(block.Receipts()) > 0 {
+			receiptsNeeded++
+		}
+	}
+	if int(bodies) != bodiesNeeded {
+		t.Errorf("body retrieval count mismatch: have %v, want %v", bodies, bodiesNeeded)
 	}
-	if int(requested) != needed {
-		t.Fatalf("block body retrieval count mismatch: have %v, want %v", requested, needed)
+	if int(receipts) != receiptsNeeded {
+		t.Errorf("receipt retrieval count mismatch: have %v, want %v", receipts, receiptsNeeded)
 	}
 }
 
 // Tests that headers are enqueued continuously, preventing malicious nodes from
 // stalling the downloader by feeding gapped header chains.
-func TestMissingHeaderAttack62(t *testing.T) { testMissingHeaderAttack(t, 62) }
-func TestMissingHeaderAttack63(t *testing.T) { testMissingHeaderAttack(t, 63) }
-func TestMissingHeaderAttack64(t *testing.T) { testMissingHeaderAttack(t, 64) }
-
-func testMissingHeaderAttack(t *testing.T, protocol int) {
+func TestMissingHeaderAttack62(t *testing.T)      { testMissingHeaderAttack(t, 62, FullSync) }
+func TestMissingHeaderAttack63Full(t *testing.T)  { testMissingHeaderAttack(t, 63, FullSync) }
+func TestMissingHeaderAttack63Fast(t *testing.T)  { testMissingHeaderAttack(t, 63, FastSync) }
+func TestMissingHeaderAttack64Full(t *testing.T)  { testMissingHeaderAttack(t, 64, FullSync) }
+func TestMissingHeaderAttack64Fast(t *testing.T)  { testMissingHeaderAttack(t, 64, FastSync) }
+func TestMissingHeaderAttack64Light(t *testing.T) { testMissingHeaderAttack(t, 64, LightSync) }
+
+func testMissingHeaderAttack(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
-	tester := newTester()
+	tester := newTester(mode)
 
 	// Attempt a full sync with an attacker feeding gapped headers
-	tester.newPeer("attack", protocol, hashes, blocks)
+	tester.newPeer("attack", protocol, hashes, headers, blocks)
 	missing := targetBlocks / 2
+	delete(tester.peerHeaders["attack"], hashes[missing])
 	delete(tester.peerBlocks["attack"], hashes[missing])
 
 	if err := tester.sync("attack", nil); err == nil {
 		t.Fatalf("succeeded attacker synchronisation")
 	}
 	// Synchronise with the valid peer and make sure sync succeeds
-	tester.newPeer("valid", protocol, hashes, blocks)
+	tester.newPeer("valid", protocol, hashes, headers, blocks)
 	if err := tester.sync("valid", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != len(hashes) {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, len(hashes))
-	}
+	assertOwnChain(t, tester, targetBlocks+1)
 }
 
 // Tests that if requested headers are shifted (i.e. first is missing), the queue
 // detects the invalid numbering.
-func TestShiftedHeaderAttack62(t *testing.T) { testShiftedHeaderAttack(t, 62) }
-func TestShiftedHeaderAttack63(t *testing.T) { testShiftedHeaderAttack(t, 63) }
-func TestShiftedHeaderAttack64(t *testing.T) { testShiftedHeaderAttack(t, 64) }
-
-func testShiftedHeaderAttack(t *testing.T, protocol int) {
+func TestShiftedHeaderAttack62(t *testing.T)      { testShiftedHeaderAttack(t, 62, FullSync) }
+func TestShiftedHeaderAttack63Full(t *testing.T)  { testShiftedHeaderAttack(t, 63, FullSync) }
+func TestShiftedHeaderAttack63Fast(t *testing.T)  { testShiftedHeaderAttack(t, 63, FastSync) }
+func TestShiftedHeaderAttack64Full(t *testing.T)  { testShiftedHeaderAttack(t, 64, FullSync) }
+func TestShiftedHeaderAttack64Fast(t *testing.T)  { testShiftedHeaderAttack(t, 64, FastSync) }
+func TestShiftedHeaderAttack64Light(t *testing.T) { testShiftedHeaderAttack(t, 64, LightSync) }
+
+func testShiftedHeaderAttack(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
-	tester := newTester()
+	tester := newTester(mode)
 
 	// Attempt a full sync with an attacker feeding shifted headers
-	tester.newPeer("attack", protocol, hashes, blocks)
+	tester.newPeer("attack", protocol, hashes, headers, blocks)
+	delete(tester.peerHeaders["attack"], hashes[len(hashes)-2])
 	delete(tester.peerBlocks["attack"], hashes[len(hashes)-2])
 
 	if err := tester.sync("attack", nil); err == nil {
 		t.Fatalf("succeeded attacker synchronisation")
 	}
 	// Synchronise with the valid peer and make sure sync succeeds
-	tester.newPeer("valid", protocol, hashes, blocks)
+	tester.newPeer("valid", protocol, hashes, headers, blocks)
 	if err := tester.sync("valid", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != len(hashes) {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, len(hashes))
-	}
+	assertOwnChain(t, tester, targetBlocks+1)
 }
 
-// Tests that if a peer sends an invalid body for a requested block, it gets
-// dropped immediately by the downloader.
-func TestInvalidBlockBodyAttack62(t *testing.T) { testInvalidBlockBodyAttack(t, 62) }
-func TestInvalidBlockBodyAttack63(t *testing.T) { testInvalidBlockBodyAttack(t, 63) }
-func TestInvalidBlockBodyAttack64(t *testing.T) { testInvalidBlockBodyAttack(t, 64) }
+// Tests that if a peer sends an invalid block piece (body or receipt) for a
+// requested block, it gets dropped immediately by the downloader.
+func TestInvalidContentAttack62(t *testing.T)      { testInvalidContentAttack(t, 62, FullSync) }
+func TestInvalidContentAttack63Full(t *testing.T)  { testInvalidContentAttack(t, 63, FullSync) }
+func TestInvalidContentAttack63Fast(t *testing.T)  { testInvalidContentAttack(t, 63, FastSync) }
+func TestInvalidContentAttack64Full(t *testing.T)  { testInvalidContentAttack(t, 64, FullSync) }
+func TestInvalidContentAttack64Fast(t *testing.T)  { testInvalidContentAttack(t, 64, FastSync) }
+func TestInvalidContentAttack64Light(t *testing.T) { testInvalidContentAttack(t, 64, LightSync) }
 
-func testInvalidBlockBodyAttack(t *testing.T, protocol int) {
+func testInvalidContentAttack(t *testing.T, protocol int, mode SyncMode) {
 	// Create two peers, one feeding invalid block bodies
 	targetBlocks := 4*blockCacheLimit - 15
-	hashes, validBlocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, validBlocks := makeChain(targetBlocks, 0, genesis)
 
 	invalidBlocks := make(map[common.Hash]*types.Block)
 	for hash, block := range validBlocks {
 		invalidBlocks[hash] = types.NewBlockWithHeader(block.Header())
 	}
+	invalidReceipts := make(map[common.Hash]*types.Block)
+	for hash, block := range validBlocks {
+		invalidReceipts[hash] = types.NewBlockWithHeader(block.Header()).WithBody(block.Transactions(), block.Uncles())
+	}
 
-	tester := newTester()
-	tester.newPeer("valid", protocol, hashes, validBlocks)
-	tester.newPeer("attack", protocol, hashes, invalidBlocks)
-
+	tester := newTester(mode)
+	tester.newPeer("valid", protocol, hashes, headers, validBlocks)
+	if mode != LightSync {
+		tester.newPeer("body attack", protocol, hashes, headers, invalidBlocks)
+	}
+	if mode == FastSync {
+		tester.newPeer("receipt attack", protocol, hashes, headers, invalidReceipts)
+	}
 	// Synchronise with the valid peer (will pull contents from the attacker too)
 	if err := tester.sync("valid", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
-	if imported := len(tester.ownBlocks); imported != len(hashes) {
-		t.Fatalf("synchronised block mismatch: have %v, want %v", imported, len(hashes))
-	}
+	assertOwnChain(t, tester, targetBlocks+1)
+
 	// Make sure the attacker was detected and dropped in the mean time
-	if _, ok := tester.peerHashes["attack"]; ok {
+	if _, ok := tester.peerHashes["body attack"]; ok {
 		t.Fatalf("block body attacker not detected/dropped")
 	}
+	if _, ok := tester.peerHashes["receipt attack"]; ok {
+		t.Fatalf("receipt attacker not detected/dropped")
+	}
 }
 
 // Tests that a peer advertising an high TD doesn't get to stall the downloader
 // afterwards by not sending any useful hashes.
-func TestHighTDStarvationAttack61(t *testing.T) { testHighTDStarvationAttack(t, 61) }
-func TestHighTDStarvationAttack62(t *testing.T) { testHighTDStarvationAttack(t, 62) }
-func TestHighTDStarvationAttack63(t *testing.T) { testHighTDStarvationAttack(t, 63) }
-func TestHighTDStarvationAttack64(t *testing.T) { testHighTDStarvationAttack(t, 64) }
-
-func testHighTDStarvationAttack(t *testing.T, protocol int) {
-	tester := newTester()
-	hashes, blocks := makeChain(0, 0, genesis)
-
-	tester.newPeer("attack", protocol, []common.Hash{hashes[0]}, blocks)
+func TestHighTDStarvationAttack61(t *testing.T)      { testHighTDStarvationAttack(t, 61, FullSync) }
+func TestHighTDStarvationAttack62(t *testing.T)      { testHighTDStarvationAttack(t, 62, FullSync) }
+func TestHighTDStarvationAttack63Full(t *testing.T)  { testHighTDStarvationAttack(t, 63, FullSync) }
+func TestHighTDStarvationAttack63Fast(t *testing.T)  { testHighTDStarvationAttack(t, 63, FastSync) }
+func TestHighTDStarvationAttack64Full(t *testing.T)  { testHighTDStarvationAttack(t, 64, FullSync) }
+func TestHighTDStarvationAttack64Fast(t *testing.T)  { testHighTDStarvationAttack(t, 64, FastSync) }
+func TestHighTDStarvationAttack64Light(t *testing.T) { testHighTDStarvationAttack(t, 64, LightSync) }
+
+func testHighTDStarvationAttack(t *testing.T, protocol int, mode SyncMode) {
+	tester := newTester(mode)
+	hashes, headers, blocks := makeChain(0, 0, genesis)
+
+	tester.newPeer("attack", protocol, []common.Hash{hashes[0]}, headers, blocks)
 	if err := tester.sync("attack", big.NewInt(1000000)); err != errStallingPeer {
 		t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errStallingPeer)
 	}
@@ -834,18 +1027,20 @@ func testBlockHeaderAttackerDropping(t *testing.T, protocol int) {
 		{errEmptyHeaderSet, true},     // No headers were returned as a response, drop as it's a dead end
 		{errPeersUnavailable, true},   // Nobody had the advertised blocks, drop the advertiser
 		{errInvalidChain, true},       // Hash chain was detected as invalid, definitely drop
+		{errInvalidBlock, false},      // A bad peer was detected, but not the sync origin
 		{errInvalidBody, false},       // A bad peer was detected, but not the sync origin
+		{errInvalidReceipt, false},    // A bad peer was detected, but not the sync origin
 		{errCancelHashFetch, false},   // Synchronisation was canceled, origin may be innocent, don't drop
 		{errCancelBlockFetch, false},  // Synchronisation was canceled, origin may be innocent, don't drop
 		{errCancelHeaderFetch, false}, // Synchronisation was canceled, origin may be innocent, don't drop
 		{errCancelBodyFetch, false},   // Synchronisation was canceled, origin may be innocent, don't drop
 	}
 	// Run the tests and check disconnection status
-	tester := newTester()
+	tester := newTester(FullSync)
 	for i, tt := range tests {
 		// Register a new peer and ensure it's presence
 		id := fmt.Sprintf("test %d", i)
-		if err := tester.newPeer(id, protocol, []common.Hash{genesis.Hash()}, nil); err != nil {
+		if err := tester.newPeer(id, protocol, []common.Hash{genesis.Hash()}, nil, nil); err != nil {
 			t.Fatalf("test %d: failed to register new peer: %v", i, err)
 		}
 		if _, ok := tester.peerHashes[id]; !ok {
@@ -861,67 +1056,26 @@ func testBlockHeaderAttackerDropping(t *testing.T, protocol int) {
 	}
 }
 
-// Tests that feeding bad blocks will result in a peer drop.
-func TestBlockBodyAttackerDropping61(t *testing.T) { testBlockBodyAttackerDropping(t, 61) }
-func TestBlockBodyAttackerDropping62(t *testing.T) { testBlockBodyAttackerDropping(t, 62) }
-func TestBlockBodyAttackerDropping63(t *testing.T) { testBlockBodyAttackerDropping(t, 63) }
-func TestBlockBodyAttackerDropping64(t *testing.T) { testBlockBodyAttackerDropping(t, 64) }
-
-func testBlockBodyAttackerDropping(t *testing.T, protocol int) {
-	// Define the disconnection requirement for individual block import errors
-	tests := []struct {
-		failure bool
-		drop    bool
-	}{
-		{true, true},
-		{false, false},
-	}
-
-	// Run the tests and check disconnection status
-	tester := newTester()
-	for i, tt := range tests {
-		// Register a new peer and ensure it's presence
-		id := fmt.Sprintf("test %d", i)
-		if err := tester.newPeer(id, protocol, []common.Hash{common.Hash{}}, nil); err != nil {
-			t.Fatalf("test %d: failed to register new peer: %v", i, err)
-		}
-		if _, ok := tester.peerHashes[id]; !ok {
-			t.Fatalf("test %d: registered peer not found", i)
-		}
-		// Assemble a good or bad block, depending of the test
-		raw := core.GenerateChain(genesis, testdb, 1, nil)[0]
-		if tt.failure {
-			parent := types.NewBlock(&types.Header{}, nil, nil, nil)
-			raw = core.GenerateChain(parent, testdb, 1, nil)[0]
-		}
-		block := &Block{OriginPeer: id, RawBlock: raw}
-
-		// Simulate block processing and check the result
-		tester.downloader.queue.blockCache[0] = block
-		tester.downloader.process()
-		if _, ok := tester.peerHashes[id]; !ok != tt.drop {
-			t.Errorf("test %d: peer drop mismatch for %v: have %v, want %v", i, tt.failure, !ok, tt.drop)
-		}
-	}
-}
-
 // Tests that synchronisation boundaries (origin block number and highest block
 // number) is tracked and updated correctly.
-func TestSyncBoundaries61(t *testing.T) { testSyncBoundaries(t, 61) }
-func TestSyncBoundaries62(t *testing.T) { testSyncBoundaries(t, 62) }
-func TestSyncBoundaries63(t *testing.T) { testSyncBoundaries(t, 63) }
-func TestSyncBoundaries64(t *testing.T) { testSyncBoundaries(t, 64) }
-
-func testSyncBoundaries(t *testing.T, protocol int) {
+func TestSyncBoundaries61(t *testing.T)      { testSyncBoundaries(t, 61, FullSync) }
+func TestSyncBoundaries62(t *testing.T)      { testSyncBoundaries(t, 62, FullSync) }
+func TestSyncBoundaries63Full(t *testing.T)  { testSyncBoundaries(t, 63, FullSync) }
+func TestSyncBoundaries63Fast(t *testing.T)  { testSyncBoundaries(t, 63, FastSync) }
+func TestSyncBoundaries64Full(t *testing.T)  { testSyncBoundaries(t, 64, FullSync) }
+func TestSyncBoundaries64Fast(t *testing.T)  { testSyncBoundaries(t, 64, FastSync) }
+func TestSyncBoundaries64Light(t *testing.T) { testSyncBoundaries(t, 64, LightSync) }
+
+func testSyncBoundaries(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
 	// Set a sync init hook to catch boundary changes
 	starting := make(chan struct{})
 	progress := make(chan struct{})
 
-	tester := newTester()
+	tester := newTester(mode)
 	tester.downloader.syncInitHook = func(origin, latest uint64) {
 		starting <- struct{}{}
 		<-progress
@@ -931,7 +1085,7 @@ func testSyncBoundaries(t *testing.T, protocol int) {
 		t.Fatalf("Pristine boundary mismatch: have %v/%v, want %v/%v", origin, latest, 0, 0)
 	}
 	// Synchronise half the blocks and check initial boundaries
-	tester.newPeer("peer-half", protocol, hashes[targetBlocks/2:], blocks)
+	tester.newPeer("peer-half", protocol, hashes[targetBlocks/2:], headers, blocks)
 	pending := new(sync.WaitGroup)
 	pending.Add(1)
 
@@ -949,7 +1103,7 @@ func testSyncBoundaries(t *testing.T, protocol int) {
 	pending.Wait()
 
 	// Synchronise all the blocks and check continuation boundaries
-	tester.newPeer("peer-full", protocol, hashes, blocks)
+	tester.newPeer("peer-full", protocol, hashes, headers, blocks)
 	pending.Add(1)
 
 	go func() {
@@ -969,21 +1123,24 @@ func testSyncBoundaries(t *testing.T, protocol int) {
 // Tests that synchronisation boundaries (origin block number and highest block
 // number) is tracked and updated correctly in case of a fork (or manual head
 // revertal).
-func TestForkedSyncBoundaries61(t *testing.T) { testForkedSyncBoundaries(t, 61) }
-func TestForkedSyncBoundaries62(t *testing.T) { testForkedSyncBoundaries(t, 62) }
-func TestForkedSyncBoundaries63(t *testing.T) { testForkedSyncBoundaries(t, 63) }
-func TestForkedSyncBoundaries64(t *testing.T) { testForkedSyncBoundaries(t, 64) }
-
-func testForkedSyncBoundaries(t *testing.T, protocol int) {
+func TestForkedSyncBoundaries61(t *testing.T)      { testForkedSyncBoundaries(t, 61, FullSync) }
+func TestForkedSyncBoundaries62(t *testing.T)      { testForkedSyncBoundaries(t, 62, FullSync) }
+func TestForkedSyncBoundaries63Full(t *testing.T)  { testForkedSyncBoundaries(t, 63, FullSync) }
+func TestForkedSyncBoundaries63Fast(t *testing.T)  { testForkedSyncBoundaries(t, 63, FastSync) }
+func TestForkedSyncBoundaries64Full(t *testing.T)  { testForkedSyncBoundaries(t, 64, FullSync) }
+func TestForkedSyncBoundaries64Fast(t *testing.T)  { testForkedSyncBoundaries(t, 64, FastSync) }
+func TestForkedSyncBoundaries64Light(t *testing.T) { testForkedSyncBoundaries(t, 64, LightSync) }
+
+func testForkedSyncBoundaries(t *testing.T, protocol int, mode SyncMode) {
 	// Create a forked chain to simulate origin revertal
 	common, fork := MaxHashFetch, 2*MaxHashFetch
-	hashesA, hashesB, blocksA, blocksB := makeChainFork(common+fork, fork, genesis)
+	hashesA, hashesB, headersA, headersB, blocksA, blocksB := makeChainFork(common+fork, fork, genesis)
 
 	// Set a sync init hook to catch boundary changes
 	starting := make(chan struct{})
 	progress := make(chan struct{})
 
-	tester := newTester()
+	tester := newTester(mode)
 	tester.downloader.syncInitHook = func(origin, latest uint64) {
 		starting <- struct{}{}
 		<-progress
@@ -993,7 +1150,7 @@ func testForkedSyncBoundaries(t *testing.T, protocol int) {
 		t.Fatalf("Pristine boundary mismatch: have %v/%v, want %v/%v", origin, latest, 0, 0)
 	}
 	// Synchronise with one of the forks and check boundaries
-	tester.newPeer("fork A", protocol, hashesA, blocksA)
+	tester.newPeer("fork A", protocol, hashesA, headersA, blocksA)
 	pending := new(sync.WaitGroup)
 	pending.Add(1)
 
@@ -1014,7 +1171,7 @@ func testForkedSyncBoundaries(t *testing.T, protocol int) {
 	tester.downloader.syncStatsOrigin = tester.downloader.syncStatsHeight
 
 	// Synchronise with the second fork and check boundary resets
-	tester.newPeer("fork B", protocol, hashesB, blocksB)
+	tester.newPeer("fork B", protocol, hashesB, headersB, blocksB)
 	pending.Add(1)
 
 	go func() {
@@ -1034,21 +1191,24 @@ func testForkedSyncBoundaries(t *testing.T, protocol int) {
 // Tests that if synchronisation is aborted due to some failure, then the boundary
 // origin is not updated in the next sync cycle, as it should be considered the
 // continuation of the previous sync and not a new instance.
-func TestFailedSyncBoundaries61(t *testing.T) { testFailedSyncBoundaries(t, 61) }
-func TestFailedSyncBoundaries62(t *testing.T) { testFailedSyncBoundaries(t, 62) }
-func TestFailedSyncBoundaries63(t *testing.T) { testFailedSyncBoundaries(t, 63) }
-func TestFailedSyncBoundaries64(t *testing.T) { testFailedSyncBoundaries(t, 64) }
-
-func testFailedSyncBoundaries(t *testing.T, protocol int) {
+func TestFailedSyncBoundaries61(t *testing.T)      { testFailedSyncBoundaries(t, 61, FullSync) }
+func TestFailedSyncBoundaries62(t *testing.T)      { testFailedSyncBoundaries(t, 62, FullSync) }
+func TestFailedSyncBoundaries63Full(t *testing.T)  { testFailedSyncBoundaries(t, 63, FullSync) }
+func TestFailedSyncBoundaries63Fast(t *testing.T)  { testFailedSyncBoundaries(t, 63, FastSync) }
+func TestFailedSyncBoundaries64Full(t *testing.T)  { testFailedSyncBoundaries(t, 64, FullSync) }
+func TestFailedSyncBoundaries64Fast(t *testing.T)  { testFailedSyncBoundaries(t, 64, FastSync) }
+func TestFailedSyncBoundaries64Light(t *testing.T) { testFailedSyncBoundaries(t, 64, LightSync) }
+
+func testFailedSyncBoundaries(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks, 0, genesis)
 
 	// Set a sync init hook to catch boundary changes
 	starting := make(chan struct{})
 	progress := make(chan struct{})
 
-	tester := newTester()
+	tester := newTester(mode)
 	tester.downloader.syncInitHook = func(origin, latest uint64) {
 		starting <- struct{}{}
 		<-progress
@@ -1058,8 +1218,9 @@ func testFailedSyncBoundaries(t *testing.T, protocol int) {
 		t.Fatalf("Pristine boundary mismatch: have %v/%v, want %v/%v", origin, latest, 0, 0)
 	}
 	// Attempt a full sync with a faulty peer
-	tester.newPeer("faulty", protocol, hashes, blocks)
+	tester.newPeer("faulty", protocol, hashes, headers, blocks)
 	missing := targetBlocks / 2
+	delete(tester.peerHeaders["faulty"], hashes[missing])
 	delete(tester.peerBlocks["faulty"], hashes[missing])
 
 	pending := new(sync.WaitGroup)
@@ -1079,7 +1240,7 @@ func testFailedSyncBoundaries(t *testing.T, protocol int) {
 	pending.Wait()
 
 	// Synchronise with a good peer and check that the boundary origin remind the same after a failure
-	tester.newPeer("valid", protocol, hashes, blocks)
+	tester.newPeer("valid", protocol, hashes, headers, blocks)
 	pending.Add(1)
 
 	go func() {
@@ -1098,21 +1259,24 @@ func testFailedSyncBoundaries(t *testing.T, protocol int) {
 
 // Tests that if an attacker fakes a chain height, after the attack is detected,
 // the boundary height is successfully reduced at the next sync invocation.
-func TestFakedSyncBoundaries61(t *testing.T) { testFakedSyncBoundaries(t, 61) }
-func TestFakedSyncBoundaries62(t *testing.T) { testFakedSyncBoundaries(t, 62) }
-func TestFakedSyncBoundaries63(t *testing.T) { testFakedSyncBoundaries(t, 63) }
-func TestFakedSyncBoundaries64(t *testing.T) { testFakedSyncBoundaries(t, 64) }
-
-func testFakedSyncBoundaries(t *testing.T, protocol int) {
+func TestFakedSyncBoundaries61(t *testing.T)      { testFakedSyncBoundaries(t, 61, FullSync) }
+func TestFakedSyncBoundaries62(t *testing.T)      { testFakedSyncBoundaries(t, 62, FullSync) }
+func TestFakedSyncBoundaries63Full(t *testing.T)  { testFakedSyncBoundaries(t, 63, FullSync) }
+func TestFakedSyncBoundaries63Fast(t *testing.T)  { testFakedSyncBoundaries(t, 63, FastSync) }
+func TestFakedSyncBoundaries64Full(t *testing.T)  { testFakedSyncBoundaries(t, 64, FullSync) }
+func TestFakedSyncBoundaries64Fast(t *testing.T)  { testFakedSyncBoundaries(t, 64, FastSync) }
+func TestFakedSyncBoundaries64Light(t *testing.T) { testFakedSyncBoundaries(t, 64, LightSync) }
+
+func testFakedSyncBoundaries(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small block chain
 	targetBlocks := blockCacheLimit - 15
-	hashes, blocks := makeChain(targetBlocks+3, 0, genesis)
+	hashes, headers, blocks := makeChain(targetBlocks+3, 0, genesis)
 
 	// Set a sync init hook to catch boundary changes
 	starting := make(chan struct{})
 	progress := make(chan struct{})
 
-	tester := newTester()
+	tester := newTester(mode)
 	tester.downloader.syncInitHook = func(origin, latest uint64) {
 		starting <- struct{}{}
 		<-progress
@@ -1122,8 +1286,9 @@ func testFakedSyncBoundaries(t *testing.T, protocol int) {
 		t.Fatalf("Pristine boundary mismatch: have %v/%v, want %v/%v", origin, latest, 0, 0)
 	}
 	//  Create and sync with an attacker that promises a higher chain than available
-	tester.newPeer("attack", protocol, hashes, blocks)
+	tester.newPeer("attack", protocol, hashes, headers, blocks)
 	for i := 1; i < 3; i++ {
+		delete(tester.peerHeaders["attack"], hashes[i])
 		delete(tester.peerBlocks["attack"], hashes[i])
 	}
 
@@ -1144,7 +1309,7 @@ func testFakedSyncBoundaries(t *testing.T, protocol int) {
 	pending.Wait()
 
 	// Synchronise with a good peer and check that the boundary height has been reduced to the true value
-	tester.newPeer("valid", protocol, hashes[3:], blocks)
+	tester.newPeer("valid", protocol, hashes[3:], headers, blocks)
 	pending.Add(1)
 
 	go func() {

eth/downloader/metrics.go

@@ -42,4 +42,9 @@ var (
 	bodyReqTimer     = metrics.NewTimer("eth/downloader/bodies/req")
 	bodyDropMeter    = metrics.NewMeter("eth/downloader/bodies/drop")
 	bodyTimeoutMeter = metrics.NewMeter("eth/downloader/bodies/timeout")
+
+	receiptInMeter      = metrics.NewMeter("eth/downloader/receipts/in")
+	receiptReqTimer     = metrics.NewTimer("eth/downloader/receipts/req")
+	receiptDropMeter    = metrics.NewMeter("eth/downloader/receipts/drop")
+	receiptTimeoutMeter = metrics.NewMeter("eth/downloader/receipts/timeout")
 )

eth/downloader/modes.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package downloader
+
+// SyncMode represents the synchronisation mode of the downloader.
+type SyncMode int
+
+const (
+	FullSync  SyncMode = iota // Synchronise the entire block-chain history from full blocks
+	FastSync                  // Quikcly download the headers, full sync only at the chain head
+	LightSync                 // Download only the headers and terminate afterwards
+)

eth/downloader/peer.go

@@ -36,10 +36,11 @@ type relativeHashFetcherFn func(common.Hash) error
 type absoluteHashFetcherFn func(uint64, int) error
 type blockFetcherFn func([]common.Hash) error
 
-// Block header and body fethers belonging to eth/62 and above
+// Block header and body fetchers belonging to eth/62 and above
 type relativeHeaderFetcherFn func(common.Hash, int, int, bool) error
 type absoluteHeaderFetcherFn func(uint64, int, int, bool) error
 type blockBodyFetcherFn func([]common.Hash) error
+type receiptFetcherFn func([]common.Hash) error
 
 var (
 	errAlreadyFetching   = errors.New("already fetching blocks from peer")
@@ -52,11 +53,14 @@ type peer struct {
 	id   string      // Unique identifier of the peer
 	head common.Hash // Hash of the peers latest known block
 
-	idle int32 // Current activity state of the peer (idle = 0, active = 1)
-	rep  int32 // Simple peer reputation
+	blockIdle   int32 // Current block activity state of the peer (idle = 0, active = 1)
+	receiptIdle int32 // Current receipt activity state of the peer (idle = 0, active = 1)
+	rep         int32 // Simple peer reputation
 
-	capacity int32     // Number of blocks allowed to fetch per request
-	started  time.Time // Time instance when the last fetch was started
+	blockCapacity   int32     // Number of blocks (bodies) allowed to fetch per request
+	receiptCapacity int32     // Number of receipts allowed to fetch per request
+	blockStarted    time.Time // Time instance when the last block (body)fetch was started
+	receiptStarted  time.Time // Time instance when the last receipt fetch was started
 
 	ignored *set.Set // Set of hashes not to request (didn't have previously)
 
@@ -68,6 +72,8 @@ type peer struct {
 	getAbsHeaders  absoluteHeaderFetcherFn // [eth/62] Method to retrieve a batch of headers from an absolute position
 	getBlockBodies blockBodyFetcherFn      // [eth/62] Method to retrieve a batch of block bodies
 
+	getReceipts receiptFetcherFn // [eth/63] Method to retrieve a batch of block transaction receipts
+
 	version int // Eth protocol version number to switch strategies
 }
 
@@ -75,12 +81,14 @@ type peer struct {
 // mechanisms.
 func newPeer(id string, version int, head common.Hash,
 	getRelHashes relativeHashFetcherFn, getAbsHashes absoluteHashFetcherFn, getBlocks blockFetcherFn, // eth/61 callbacks, remove when upgrading
-	getRelHeaders relativeHeaderFetcherFn, getAbsHeaders absoluteHeaderFetcherFn, getBlockBodies blockBodyFetcherFn) *peer {
+	getRelHeaders relativeHeaderFetcherFn, getAbsHeaders absoluteHeaderFetcherFn, getBlockBodies blockBodyFetcherFn,
+	getReceipts receiptFetcherFn) *peer {
 	return &peer{
-		id:       id,
-		head:     head,
-		capacity: 1,
-		ignored:  set.New(),
+		id:              id,
+		head:            head,
+		blockCapacity:   1,
+		receiptCapacity: 1,
+		ignored:         set.New(),
 
 		getRelHashes: getRelHashes,
 		getAbsHashes: getAbsHashes,
@@ -90,24 +98,28 @@ func newPeer(id string, version int, head common.Hash,
 		getAbsHeaders:  getAbsHeaders,
 		getBlockBodies: getBlockBodies,
 
+		getReceipts: getReceipts,
+
 		version: version,
 	}
 }
 
 // Reset clears the internal state of a peer entity.
 func (p *peer) Reset() {
-	atomic.StoreInt32(&p.idle, 0)
-	atomic.StoreInt32(&p.capacity, 1)
+	atomic.StoreInt32(&p.blockIdle, 0)
+	atomic.StoreInt32(&p.receiptIdle, 0)
+	atomic.StoreInt32(&p.blockCapacity, 1)
+	atomic.StoreInt32(&p.receiptCapacity, 1)
 	p.ignored.Clear()
 }
 
 // Fetch61 sends a block retrieval request to the remote peer.
 func (p *peer) Fetch61(request *fetchRequest) error {
 	// Short circuit if the peer is already fetching
-	if !atomic.CompareAndSwapInt32(&p.idle, 0, 1) {
+	if !atomic.CompareAndSwapInt32(&p.blockIdle, 0, 1) {
 		return errAlreadyFetching
 	}
-	p.started = time.Now()
+	p.blockStarted = time.Now()
 
 	// Convert the hash set to a retrievable slice
 	hashes := make([]common.Hash, 0, len(request.Hashes))
@@ -119,13 +131,13 @@ func (p *peer) Fetch61(request *fetchRequest) error {
 	return nil
 }
 
-// Fetch sends a block body retrieval request to the remote peer.
-func (p *peer) Fetch(request *fetchRequest) error {
+// FetchBodies sends a block body retrieval request to the remote peer.
+func (p *peer) FetchBodies(request *fetchRequest) error {
 	// Short circuit if the peer is already fetching
-	if !atomic.CompareAndSwapInt32(&p.idle, 0, 1) {
+	if !atomic.CompareAndSwapInt32(&p.blockIdle, 0, 1) {
 		return errAlreadyFetching
 	}
-	p.started = time.Now()
+	p.blockStarted = time.Now()
 
 	// Convert the header set to a retrievable slice
 	hashes := make([]common.Hash, 0, len(request.Headers))
@@ -137,55 +149,64 @@ func (p *peer) Fetch(request *fetchRequest) error {
 	return nil
 }
 
-// SetIdle61 sets the peer to idle, allowing it to execute new retrieval requests.
-// Its block retrieval allowance will also be updated either up- or downwards,
-// depending on whether the previous fetch completed in time or not.
-func (p *peer) SetIdle61() {
-	// Update the peer's download allowance based on previous performance
-	scale := 2.0
-	if time.Since(p.started) > blockSoftTTL {
-		scale = 0.5
-		if time.Since(p.started) > blockHardTTL {
-			scale = 1 / float64(MaxBlockFetch) // reduces capacity to 1
-		}
+// FetchReceipts sends a receipt retrieval request to the remote peer.
+func (p *peer) FetchReceipts(request *fetchRequest) error {
+	// Short circuit if the peer is already fetching
+	if !atomic.CompareAndSwapInt32(&p.receiptIdle, 0, 1) {
+		return errAlreadyFetching
 	}
-	for {
-		// Calculate the new download bandwidth allowance
-		prev := atomic.LoadInt32(&p.capacity)
-		next := int32(math.Max(1, math.Min(float64(MaxBlockFetch), float64(prev)*scale)))
+	p.receiptStarted = time.Now()
 
-		// Try to update the old value
-		if atomic.CompareAndSwapInt32(&p.capacity, prev, next) {
-			// If we're having problems at 1 capacity, try to find better peers
-			if next == 1 {
-				p.Demote()
-			}
-			break
-		}
+	// Convert the header set to a retrievable slice
+	hashes := make([]common.Hash, 0, len(request.Headers))
+	for _, header := range request.Headers {
+		hashes = append(hashes, header.Hash())
 	}
-	// Set the peer to idle to allow further block requests
-	atomic.StoreInt32(&p.idle, 0)
+	go p.getReceipts(hashes)
+
+	return nil
+}
+
+// SetBlocksIdle sets the peer to idle, allowing it to execute new retrieval requests.
+// Its block retrieval allowance will also be updated either up- or downwards,
+// depending on whether the previous fetch completed in time or not.
+func (p *peer) SetBlocksIdle() {
+	p.setIdle(p.blockStarted, blockSoftTTL, blockHardTTL, MaxBlockFetch, &p.blockCapacity, &p.blockIdle)
 }
 
-// SetIdle sets the peer to idle, allowing it to execute new retrieval requests.
+// SetBodiesIdle sets the peer to idle, allowing it to execute new retrieval requests.
 // Its block body retrieval allowance will also be updated either up- or downwards,
 // depending on whether the previous fetch completed in time or not.
-func (p *peer) SetIdle() {
+func (p *peer) SetBodiesIdle() {
+	p.setIdle(p.blockStarted, bodySoftTTL, bodyHardTTL, MaxBlockFetch, &p.blockCapacity, &p.blockIdle)
+}
+
+// SetReceiptsIdle sets the peer to idle, allowing it to execute new retrieval requests.
+// Its receipt retrieval allowance will also be updated either up- or downwards,
+// depending on whether the previous fetch completed in time or not.
+func (p *peer) SetReceiptsIdle() {
+	p.setIdle(p.receiptStarted, receiptSoftTTL, receiptHardTTL, MaxReceiptFetch, &p.receiptCapacity, &p.receiptIdle)
+}
+
+// setIdle sets the peer to idle, allowing it to execute new retrieval requests.
+// Its data retrieval allowance will also be updated either up- or downwards,
+// depending on whether the previous fetch completed in time or not.
+func (p *peer) setIdle(started time.Time, softTTL, hardTTL time.Duration, maxFetch int, capacity, idle *int32) {
 	// Update the peer's download allowance based on previous performance
 	scale := 2.0
-	if time.Since(p.started) > bodySoftTTL {
+	if time.Since(started) > softTTL {
 		scale = 0.5
-		if time.Since(p.started) > bodyHardTTL {
-			scale = 1 / float64(MaxBodyFetch) // reduces capacity to 1
+		if time.Since(started) > hardTTL {
+			scale = 1 / float64(maxFetch) // reduces capacity to 1
 		}
 	}
 	for {
 		// Calculate the new download bandwidth allowance
-		prev := atomic.LoadInt32(&p.capacity)
-		next := int32(math.Max(1, math.Min(float64(MaxBodyFetch), float64(prev)*scale)))
+		prev := atomic.LoadInt32(capacity)
+		next := int32(math.Max(1, math.Min(float64(maxFetch), float64(prev)*scale)))
 
 		// Try to update the old value
-		if atomic.CompareAndSwapInt32(&p.capacity, prev, next) {
+		if atomic.CompareAndSwapInt32(capacity, prev, next) {
 			// If we're having problems at 1 capacity, try to find better peers
 			if next == 1 {
 				p.Demote()
@@ -193,14 +214,20 @@ func (p *peer) SetIdle() {
 			break
 		}
 	}
-	// Set the peer to idle to allow further block requests
-	atomic.StoreInt32(&p.idle, 0)
+	// Set the peer to idle to allow further fetch requests
+	atomic.StoreInt32(idle, 0)
+}
+
+// BlockCapacity retrieves the peers block download allowance based on its
+// previously discovered bandwidth capacity.
+func (p *peer) BlockCapacity() int {
+	return int(atomic.LoadInt32(&p.blockCapacity))
 }
 
-// Capacity retrieves the peers block download allowance based on its previously
-// discovered bandwidth capacity.
-func (p *peer) Capacity() int {
-	return int(atomic.LoadInt32(&p.capacity))
+// ReceiptCapacity retrieves the peers block download allowance based on its
+// previously discovered bandwidth capacity.
+func (p *peer) ReceiptCapacity() int {
+	return int(atomic.LoadInt32(&p.receiptCapacity))
 }
 
 // Promote increases the peer's reputation.
@@ -226,7 +253,8 @@ func (p *peer) Demote() {
 func (p *peer) String() string {
 	return fmt.Sprintf("Peer %s [%s]", p.id,
 		fmt.Sprintf("reputation %3d, ", atomic.LoadInt32(&p.rep))+
-			fmt.Sprintf("capacity %3d, ", atomic.LoadInt32(&p.capacity))+
+			fmt.Sprintf("block cap %3d, ", atomic.LoadInt32(&p.blockCapacity))+
+			fmt.Sprintf("receipt cap %3d, ", atomic.LoadInt32(&p.receiptCapacity))+
 			fmt.Sprintf("ignored %4d", p.ignored.Size()),
 	)
 }
@@ -310,26 +338,52 @@ func (ps *peerSet) AllPeers() []*peer {
 	return list
 }
 
-// IdlePeers retrieves a flat list of all the currently idle peers within the
+// BlockIdlePeers retrieves a flat list of all the currently idle peers within the
 // active peer set, ordered by their reputation.
-func (ps *peerSet) IdlePeers(version int) []*peer {
+func (ps *peerSet) BlockIdlePeers(version int) ([]*peer, int) {
 	ps.lock.RLock()
 	defer ps.lock.RUnlock()
 
-	list := make([]*peer, 0, len(ps.peers))
+	idle, total := make([]*peer, 0, len(ps.peers)), 0
 	for _, p := range ps.peers {
-		if (version == eth61 && p.version == eth61) || (version >= eth62 && p.version >= eth62) {
-			if atomic.LoadInt32(&p.idle) == 0 {
-				list = append(list, p)
+		if (version == 61 && p.version == 61) || (version >= 62 && p.version >= 62) {
+			if atomic.LoadInt32(&p.blockIdle) == 0 {
+				idle = append(idle, p)
 			}
+			total++
 		}
 	}
-	for i := 0; i < len(list); i++ {
-		for j := i + 1; j < len(list); j++ {
-			if atomic.LoadInt32(&list[i].rep) < atomic.LoadInt32(&list[j].rep) {
-				list[i], list[j] = list[j], list[i]
+	for i := 0; i < len(idle); i++ {
+		for j := i + 1; j < len(idle); j++ {
+			if atomic.LoadInt32(&idle[i].rep) < atomic.LoadInt32(&idle[j].rep) {
+				idle[i], idle[j] = idle[j], idle[i]
 			}
 		}
 	}
-	return list
+	return idle, total
+}
+
+// ReceiptIdlePeers retrieves a flat list of all the currently idle peers within the
+// active peer set, ordered by their reputation.
+func (ps *peerSet) ReceiptIdlePeers() ([]*peer, int) {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	idle, total := make([]*peer, 0, len(ps.peers)), 0
+	for _, p := range ps.peers {
+		if p.version >= 63 {
+			if atomic.LoadInt32(&p.receiptIdle) == 0 {
+				idle = append(idle, p)
+			}
+			total++
+		}
+	}
+	for i := 0; i < len(idle); i++ {
+		for j := i + 1; j < len(idle); j++ {
+			if atomic.LoadInt32(&idle[i].rep) < atomic.LoadInt32(&idle[j].rep) {
+				idle[i], idle[j] = idle[j], idle[i]
+			}
+		}
+	}
+	return idle, total
 }

eth/downloader/queue.go

@@ -29,11 +29,12 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/rcrowley/go-metrics"
 	"gopkg.in/karalabe/cookiejar.v2/collections/prque"
 )
 
 var (
-	blockCacheLimit = 8 * MaxBlockFetch // Maximum number of blocks to cache before throttling the download
+	blockCacheLimit = 1024 // Maximum number of blocks to cache before throttling the download
 )
 
 var (
@@ -41,29 +42,47 @@ var (
 	errStaleDelivery    = errors.New("stale delivery")
 )
 
-// fetchRequest is a currently running block retrieval operation.
+// fetchRequest is a currently running data retrieval operation.
 type fetchRequest struct {
 	Peer    *peer               // Peer to which the request was sent
-	Hashes  map[common.Hash]int // [eth/61] Requested hashes with their insertion index (priority)
+	Hashes  map[common.Hash]int // [eth/61] Requested block with their insertion index (priority)
 	Headers []*types.Header     // [eth/62] Requested headers, sorted by request order
 	Time    time.Time           // Time when the request was made
 }
 
+// fetchResult is the assembly collecting partial results from potentially more
+// than one fetcher routines, until all outstanding retrievals complete and the
+// result as a whole can be processed.
+type fetchResult struct {
+	Pending int // Number of data fetches still pending
+
+	Header       *types.Header
+	Uncles       []*types.Header
+	Transactions types.Transactions
+	Receipts     types.Receipts
+}
+
 // queue represents hashes that are either need fetching or are being fetched
 type queue struct {
 	hashPool    map[common.Hash]int // [eth/61] Pending hashes, mapping to their insertion index (priority)
 	hashQueue   *prque.Prque        // [eth/61] Priority queue of the block hashes to fetch
 	hashCounter int                 // [eth/61] Counter indexing the added hashes to ensure retrieval order
 
-	headerPool  map[common.Hash]*types.Header // [eth/62] Pending headers, mapping from their hashes
-	headerQueue *prque.Prque                  // [eth/62] Priority queue of the headers to fetch the bodies for
-	headerHead  common.Hash                   // [eth/62] Hash of the last queued header to verify order
+	headerHead common.Hash // [eth/62] Hash of the last queued header to verify order
 
-	pendPool map[string]*fetchRequest // Currently pending block retrieval operations
+	blockTaskPool  map[common.Hash]*types.Header // [eth/62] Pending block (body) retrieval tasks, mapping hashes to headers
+	blockTaskQueue *prque.Prque                  // [eth/62] Priority queue of the headers to fetch the blocks (bodies) for
+	blockPendPool  map[string]*fetchRequest      // [eth/62] Currently pending block (body) retrieval operations
+	blockDonePool  map[common.Hash]struct{}      // [eth/62] Set of the completed block (body) fetches
 
-	blockPool   map[common.Hash]uint64 // Hash-set of the downloaded data blocks, mapping to cache indexes
-	blockCache  []*Block               // Downloaded but not yet delivered blocks
-	blockOffset uint64                 // Offset of the first cached block in the block-chain
+	receiptTaskPool  map[common.Hash]*types.Header // [eth/63] Pending receipt retrieval tasks, mapping hashes to headers
+	receiptTaskQueue *prque.Prque                  // [eth/63] Priority queue of the headers to fetch the receipts for
+	receiptPendPool  map[string]*fetchRequest      // [eth/63] Currently pending receipt retrieval operations
+	receiptDonePool  map[common.Hash]struct{}      // [eth/63] Set of the completed receipt fetches
+
+	resultCache  []*fetchResult // Downloaded but not yet delivered fetch results
+	resultOffset uint64         // Offset of the first cached fetch result in the block-chain
+	resultParts  int            // Number of fetch components required to complete an item
 
 	lock sync.RWMutex
 }
@@ -71,13 +90,17 @@ type queue struct {
 // newQueue creates a new download queue for scheduling block retrieval.
 func newQueue() *queue {
 	return &queue{
-		hashPool:    make(map[common.Hash]int),
-		hashQueue:   prque.New(),
-		headerPool:  make(map[common.Hash]*types.Header),
-		headerQueue: prque.New(),
-		pendPool:    make(map[string]*fetchRequest),
-		blockPool:   make(map[common.Hash]uint64),
-		blockCache:  make([]*Block, blockCacheLimit),
+		hashPool:         make(map[common.Hash]int),
+		hashQueue:        prque.New(),
+		blockTaskPool:    make(map[common.Hash]*types.Header),
+		blockTaskQueue:   prque.New(),
+		blockPendPool:    make(map[string]*fetchRequest),
+		blockDonePool:    make(map[common.Hash]struct{}),
+		receiptTaskPool:  make(map[common.Hash]*types.Header),
+		receiptTaskQueue: prque.New(),
+		receiptPendPool:  make(map[string]*fetchRequest),
+		receiptDonePool:  make(map[common.Hash]struct{}),
+		resultCache:      make([]*fetchResult, blockCacheLimit),
 	}
 }
 
@@ -90,32 +113,37 @@ func (q *queue) Reset() {
 	q.hashQueue.Reset()
 	q.hashCounter = 0
 
-	q.headerPool = make(map[common.Hash]*types.Header)
-	q.headerQueue.Reset()
 	q.headerHead = common.Hash{}
 
-	q.pendPool = make(map[string]*fetchRequest)
+	q.blockTaskPool = make(map[common.Hash]*types.Header)
+	q.blockTaskQueue.Reset()
+	q.blockPendPool = make(map[string]*fetchRequest)
+	q.blockDonePool = make(map[common.Hash]struct{})
+
+	q.receiptTaskPool = make(map[common.Hash]*types.Header)
+	q.receiptTaskQueue.Reset()
+	q.receiptPendPool = make(map[string]*fetchRequest)
+	q.receiptDonePool = make(map[common.Hash]struct{})
 
-	q.blockPool = make(map[common.Hash]uint64)
-	q.blockOffset = 0
-	q.blockCache = make([]*Block, blockCacheLimit)
+	q.resultCache = make([]*fetchResult, blockCacheLimit)
+	q.resultOffset = 0
+	q.resultParts = 0
 }
 
-// Size retrieves the number of blocks in the queue, returning separately for
-// pending and already downloaded.
-func (q *queue) Size() (int, int) {
+// PendingBlocks retrieves the number of block (body) requests pending for retrieval.
+func (q *queue) PendingBlocks() int {
 	q.lock.RLock()
 	defer q.lock.RUnlock()
 
-	return len(q.hashPool) + len(q.headerPool), len(q.blockPool)
+	return q.hashQueue.Size() + q.blockTaskQueue.Size()
 }
 
-// Pending retrieves the number of blocks pending for retrieval.
-func (q *queue) Pending() int {
+// PendingReceipts retrieves the number of block receipts pending for retrieval.
+func (q *queue) PendingReceipts() int {
 	q.lock.RLock()
 	defer q.lock.RUnlock()
 
-	return q.hashQueue.Size() + q.headerQueue.Size()
+	return q.receiptTaskQueue.Size()
 }
 
 // InFlight retrieves the number of fetch requests currently in flight.
@@ -123,44 +151,55 @@ func (q *queue) InFlight() int {
 	q.lock.RLock()
 	defer q.lock.RUnlock()
 
-	return len(q.pendPool)
+	return len(q.blockPendPool) + len(q.receiptPendPool)
+}
+
+// Idle returns if the queue is fully idle or has some data still inside. This
+// method is used by the tester to detect termination events.
+func (q *queue) Idle() bool {
+	q.lock.RLock()
+	defer q.lock.RUnlock()
+
+	queued := q.hashQueue.Size() + q.blockTaskQueue.Size() + q.receiptTaskQueue.Size()
+	pending := len(q.blockPendPool) + len(q.receiptPendPool)
+	cached := len(q.blockDonePool) + len(q.receiptDonePool)
+
+	return (queued + pending + cached) == 0
 }
 
-// Throttle checks if the download should be throttled (active block fetches
-// exceed block cache).
-func (q *queue) Throttle() bool {
+// ThrottleBlocks checks if the download should be throttled (active block (body)
+// fetches exceed block cache).
+func (q *queue) ThrottleBlocks() bool {
 	q.lock.RLock()
 	defer q.lock.RUnlock()
 
-	// Calculate the currently in-flight block requests
+	// Calculate the currently in-flight block (body) requests
 	pending := 0
-	for _, request := range q.pendPool {
+	for _, request := range q.blockPendPool {
 		pending += len(request.Hashes) + len(request.Headers)
 	}
-	// Throttle if more blocks are in-flight than free space in the cache
-	return pending >= len(q.blockCache)-len(q.blockPool)
+	// Throttle if more blocks (bodies) are in-flight than free space in the cache
+	return pending >= len(q.resultCache)-len(q.blockDonePool)
 }
 
-// Has checks if a hash is within the download queue or not.
-func (q *queue) Has(hash common.Hash) bool {
+// ThrottleReceipts checks if the download should be throttled (active receipt
+// fetches exceed block cache).
+func (q *queue) ThrottleReceipts() bool {
 	q.lock.RLock()
 	defer q.lock.RUnlock()
 
-	if _, ok := q.hashPool[hash]; ok {
-		return true
-	}
-	if _, ok := q.headerPool[hash]; ok {
-		return true
-	}
-	if _, ok := q.blockPool[hash]; ok {
-		return true
+	// Calculate the currently in-flight receipt requests
+	pending := 0
+	for _, request := range q.receiptPendPool {
+		pending += len(request.Headers)
 	}
-	return false
+	// Throttle if more receipts are in-flight than free space in the cache
+	return pending >= len(q.resultCache)-len(q.receiptDonePool)
 }
 
-// Insert61 adds a set of hashes for the download queue for scheduling, returning
+// Schedule61 adds a set of hashes for the download queue for scheduling, returning
 // the new hashes encountered.
-func (q *queue) Insert61(hashes []common.Hash, fifo bool) []common.Hash {
+func (q *queue) Schedule61(hashes []common.Hash, fifo bool) []common.Hash {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
@@ -186,22 +225,17 @@ func (q *queue) Insert61(hashes []common.Hash, fifo bool) []common.Hash {
 	return inserts
 }
 
-// Insert adds a set of headers for the download queue for scheduling, returning
+// Schedule adds a set of headers for the download queue for scheduling, returning
 // the new headers encountered.
-func (q *queue) Insert(headers []*types.Header, from uint64) []*types.Header {
+func (q *queue) Schedule(headers []*types.Header, from uint64, receipts bool) []*types.Header {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
 	// Insert all the headers prioritized by the contained block number
 	inserts := make([]*types.Header, 0, len(headers))
 	for _, header := range headers {
-		// Make sure no duplicate requests are executed
-		hash := header.Hash()
-		if _, ok := q.headerPool[hash]; ok {
-			glog.V(logger.Warn).Infof("Header #%d [%x] already scheduled", header.Number.Uint64(), hash[:4])
-			continue
-		}
 		// Make sure chain order is honored and preserved throughout
+		hash := header.Hash()
 		if header.Number == nil || header.Number.Uint64() != from {
 			glog.V(logger.Warn).Infof("Header #%v [%x] broke chain ordering, expected %d", header.Number, hash[:4], from)
 			break
@@ -210,69 +244,72 @@ func (q *queue) Insert(headers []*types.Header, from uint64) []*types.Header {
 			glog.V(logger.Warn).Infof("Header #%v [%x] broke chain ancestry", header.Number, hash[:4])
 			break
 		}
-		// Queue the header for body retrieval
+		// Make sure no duplicate requests are executed
+		if _, ok := q.blockTaskPool[hash]; ok {
+			glog.V(logger.Warn).Infof("Header #%d [%x] already scheduled for block fetch", header.Number.Uint64(), hash[:4])
+			continue
+		}
+		if _, ok := q.receiptTaskPool[hash]; ok {
+			glog.V(logger.Warn).Infof("Header #%d [%x] already scheduled for receipt fetch", header.Number.Uint64(), hash[:4])
+			continue
+		}
+		// Queue the header for content retrieval
+		q.blockTaskPool[hash] = header
+		q.blockTaskQueue.Push(header, -float32(header.Number.Uint64()))
+		if receipts {
+			q.receiptTaskPool[hash] = header
+			q.receiptTaskQueue.Push(header, -float32(header.Number.Uint64()))
+		}
 		inserts = append(inserts, header)
-		q.headerPool[hash] = header
-		q.headerQueue.Push(header, -float32(header.Number.Uint64()))
 		q.headerHead = hash
 		from++
 	}
 	return inserts
 }
 
-// GetHeadBlock retrieves the first block from the cache, or nil if it hasn't
+// GetHeadResult retrieves the first fetch result from the cache, or nil if it hasn't
 // been downloaded yet (or simply non existent).
-func (q *queue) GetHeadBlock() *Block {
+func (q *queue) GetHeadResult() *fetchResult {
 	q.lock.RLock()
 	defer q.lock.RUnlock()
 
-	if len(q.blockCache) == 0 {
+	if len(q.resultCache) == 0 || q.resultCache[0] == nil {
 		return nil
 	}
-	return q.blockCache[0]
-}
-
-// GetBlock retrieves a downloaded block, or nil if non-existent.
-func (q *queue) GetBlock(hash common.Hash) *Block {
-	q.lock.RLock()
-	defer q.lock.RUnlock()
-
-	// Short circuit if the block hasn't been downloaded yet
-	index, ok := q.blockPool[hash]
-	if !ok {
+	if q.resultCache[0].Pending > 0 {
 		return nil
 	}
-	// Return the block if it's still available in the cache
-	if q.blockOffset <= index && index < q.blockOffset+uint64(len(q.blockCache)) {
-		return q.blockCache[index-q.blockOffset]
-	}
-	return nil
+	return q.resultCache[0]
 }
 
-// TakeBlocks retrieves and permanently removes a batch of blocks from the cache.
-func (q *queue) TakeBlocks() []*Block {
+// TakeResults retrieves and permanently removes a batch of fetch results from
+// the cache.
+func (q *queue) TakeResults() []*fetchResult {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
-	// Accumulate all available blocks
-	blocks := []*Block{}
-	for _, block := range q.blockCache {
-		if block == nil {
+	// Accumulate all available results
+	results := []*fetchResult{}
+	for _, result := range q.resultCache {
+		if result == nil || result.Pending > 0 {
 			break
 		}
-		blocks = append(blocks, block)
-		delete(q.blockPool, block.RawBlock.Hash())
+		results = append(results, result)
+
+		hash := result.Header.Hash()
+		delete(q.blockDonePool, hash)
+		delete(q.receiptDonePool, hash)
 	}
-	// Delete the blocks from the slice and let them be garbage collected
-	// without this slice trick the blocks would stay in memory until nil
-	// would be assigned to q.blocks
-	copy(q.blockCache, q.blockCache[len(blocks):])
-	for k, n := len(q.blockCache)-len(blocks), len(q.blockCache); k < n; k++ {
-		q.blockCache[k] = nil
+	// Delete the results from the slice and let them be garbage collected
+	// without this slice trick the results would stay in memory until nil
+	// would be assigned to them.
+	copy(q.resultCache, q.resultCache[len(results):])
+	for k, n := len(q.resultCache)-len(results), len(q.resultCache); k < n; k++ {
+		q.resultCache[k] = nil
 	}
-	q.blockOffset += uint64(len(blocks))
+	q.resultOffset += uint64(len(results))
 
-	return blocks
+	return results
 }
 
 // Reserve61 reserves a set of hashes for the given peer, skipping any previously
@@ -286,12 +323,12 @@ func (q *queue) Reserve61(p *peer, count int) *fetchRequest {
 	if q.hashQueue.Empty() {
 		return nil
 	}
-	if _, ok := q.pendPool[p.id]; ok {
+	if _, ok := q.blockPendPool[p.id]; ok {
 		return nil
 	}
 	// Calculate an upper limit on the hashes we might fetch (i.e. throttling)
-	space := len(q.blockCache) - len(q.blockPool)
-	for _, request := range q.pendPool {
+	space := len(q.resultCache) - len(q.blockDonePool)
+	for _, request := range q.blockPendPool {
 		space -= len(request.Hashes)
 	}
 	// Retrieve a batch of hashes, skipping previously failed ones
@@ -319,49 +356,82 @@ func (q *queue) Reserve61(p *peer, count int) *fetchRequest {
 		Hashes: send,
 		Time:   time.Now(),
 	}
-	q.pendPool[p.id] = request
+	q.blockPendPool[p.id] = request
 
 	return request
 }
 
-// Reserve reserves a set of headers for the given peer, skipping any previously
-// failed download. Beside the next batch of needed fetches, it also returns a
-// flag whether empty blocks were queued requiring processing.
-func (q *queue) Reserve(p *peer, count int) (*fetchRequest, bool, error) {
+// ReserveBlocks reserves a set of body fetches for the given peer, skipping any
+// previously failed downloads. Beside the next batch of needed fetches, it also
+// returns a flag whether empty blocks were queued requiring processing.
+func (q *queue) ReserveBlocks(p *peer, count int) (*fetchRequest, bool, error) {
+	noop := func(header *types.Header) bool {
+		return header.TxHash == types.EmptyRootHash && header.UncleHash == types.EmptyUncleHash
+	}
+	return q.reserveFetch(p, count, q.blockTaskPool, q.blockTaskQueue, q.blockPendPool, q.blockDonePool, noop)
+}
+
+// ReserveReceipts reserves a set of receipt fetches for the given peer, skipping
+// any previously failed downloads. Beside the next batch of needed fetches, it
+// also returns a flag whether empty receipts were queued requiring importing.
+func (q *queue) ReserveReceipts(p *peer, count int) (*fetchRequest, bool, error) {
+	noop := func(header *types.Header) bool {
+		return header.ReceiptHash == types.EmptyRootHash
+	}
+	return q.reserveFetch(p, count, q.receiptTaskPool, q.receiptTaskQueue, q.receiptPendPool, q.receiptDonePool, noop)
+}
+
+// reserveFetch reserves a set of data download operations for a given peer,
+// skipping any previously failed ones. This method is a generic version used
+// by the individual special reservation functions.
+func (q *queue) reserveFetch(p *peer, count int, taskPool map[common.Hash]*types.Header, taskQueue *prque.Prque,
+	pendPool map[string]*fetchRequest, donePool map[common.Hash]struct{}, noop func(*types.Header) bool) (*fetchRequest, bool, error) {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
 	// Short circuit if the pool has been depleted, or if the peer's already
 	// downloading something (sanity check not to corrupt state)
-	if q.headerQueue.Empty() {
+	if taskQueue.Empty() {
 		return nil, false, nil
 	}
-	if _, ok := q.pendPool[p.id]; ok {
+	if _, ok := pendPool[p.id]; ok {
 		return nil, false, nil
 	}
-	// Calculate an upper limit on the bodies we might fetch (i.e. throttling)
-	space := len(q.blockCache) - len(q.blockPool)
-	for _, request := range q.pendPool {
+	// Calculate an upper limit on the items we might fetch (i.e. throttling)
+	space := len(q.resultCache) - len(donePool)
+	for _, request := range pendPool {
 		space -= len(request.Headers)
 	}
-	// Retrieve a batch of headers, skipping previously failed ones
+	// Retrieve a batch of tasks, skipping previously failed ones
 	send := make([]*types.Header, 0, count)
 	skip := make([]*types.Header, 0)
 
-	process := false
-	for proc := 0; proc < space && len(send) < count && !q.headerQueue.Empty(); proc++ {
-		header := q.headerQueue.PopItem().(*types.Header)
+	progress := false
+	for proc := 0; proc < space && len(send) < count && !taskQueue.Empty(); proc++ {
+		header := taskQueue.PopItem().(*types.Header)
 
-		// If the header defines an empty block, deliver straight
-		if header.TxHash == types.DeriveSha(types.Transactions{}) && header.UncleHash == types.CalcUncleHash([]*types.Header{}) {
-			if err := q.enqueue("", types.NewBlockWithHeader(header)); err != nil {
-				return nil, false, errInvalidChain
+		// If we're the first to request this task, initialize the result container
+		index := int(header.Number.Int64() - int64(q.resultOffset))
+		if index >= len(q.resultCache) || index < 0 {
+			return nil, false, errInvalidChain
+		}
+		if q.resultCache[index] == nil {
+			q.resultCache[index] = &fetchResult{
+				Pending: q.resultParts,
+				Header:  header,
 			}
-			delete(q.headerPool, header.Hash())
-			process, space, proc = true, space-1, proc-1
+		}
+		// If this fetch task is a noop, skip this fetch operation
+		if noop(header) {
+			donePool[header.Hash()] = struct{}{}
+			delete(taskPool, header.Hash())
+
+			space, proc = space-1, proc-1
+			q.resultCache[index].Pending--
+			progress = true
 			continue
 		}
-		// If it's a content block, add to the body fetch request
+		// Otherwise if not a known unknown block, add to the retrieve list
 		if p.ignored.Has(header.Hash()) {
 			skip = append(skip, header)
 		} else {
@@ -370,24 +440,41 @@ func (q *queue) Reserve(p *peer, count int) (*fetchRequest, bool, error) {
 	}
 	// Merge all the skipped headers back
 	for _, header := range skip {
-		q.headerQueue.Push(header, -float32(header.Number.Uint64()))
+		taskQueue.Push(header, -float32(header.Number.Uint64()))
 	}
 	// Assemble and return the block download request
 	if len(send) == 0 {
-		return nil, process, nil
+		return nil, progress, nil
 	}
 	request := &fetchRequest{
 		Peer:    p,
 		Headers: send,
 		Time:    time.Now(),
 	}
-	q.pendPool[p.id] = request
+	pendPool[p.id] = request
+
+	return request, progress, nil
+}
+
+// Cancel61 aborts a fetch request, returning all pending hashes to the queue.
+func (q *queue) Cancel61(request *fetchRequest) {
+	q.cancel(request, nil, q.blockPendPool)
+}
+
+// CancelBlocks aborts a body fetch request, returning all pending hashes to the
+// task queue.
+func (q *queue) CancelBlocks(request *fetchRequest) {
+	q.cancel(request, q.blockTaskQueue, q.blockPendPool)
+}
 
-	return request, process, nil
+// CancelReceipts aborts a body fetch request, returning all pending hashes to
+// the task queue.
+func (q *queue) CancelReceipts(request *fetchRequest) {
+	q.cancel(request, q.receiptTaskQueue, q.receiptPendPool)
 }
 
-// Cancel aborts a fetch request, returning all pending hashes to the queue.
-func (q *queue) Cancel(request *fetchRequest) {
+// Cancel aborts a fetch request, returning all pending hashes to the task queue.
+func (q *queue) cancel(request *fetchRequest, taskQueue *prque.Prque, pendPool map[string]*fetchRequest) {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
@@ -395,20 +482,62 @@ func (q *queue) Cancel(request *fetchRequest) {
 		q.hashQueue.Push(hash, float32(index))
 	}
 	for _, header := range request.Headers {
-		q.headerQueue.Push(header, -float32(header.Number.Uint64()))
+		taskQueue.Push(header, -float32(header.Number.Uint64()))
 	}
-	delete(q.pendPool, request.Peer.id)
+	delete(pendPool, request.Peer.id)
 }
 
-// Expire checks for in flight requests that exceeded a timeout allowance,
+// Revoke cancels all pending requests belonging to a given peer. This method is
+// meant to be called during a peer drop to quickly reassign owned data fetches
+// to remaining nodes.
+func (q *queue) Revoke(peerId string) {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+
+	if request, ok := q.blockPendPool[peerId]; ok {
+		for hash, index := range request.Hashes {
+			q.hashQueue.Push(hash, float32(index))
+		}
+		for _, header := range request.Headers {
+			q.blockTaskQueue.Push(header, -float32(header.Number.Uint64()))
+		}
+		delete(q.blockPendPool, peerId)
+	}
+	if request, ok := q.receiptPendPool[peerId]; ok {
+		for _, header := range request.Headers {
+			q.receiptTaskQueue.Push(header, -float32(header.Number.Uint64()))
+		}
+		delete(q.receiptPendPool, peerId)
+	}
+}
+
+// Expire61 checks for in flight requests that exceeded a timeout allowance,
 // canceling them and returning the responsible peers for penalization.
-func (q *queue) Expire(timeout time.Duration) []string {
+func (q *queue) Expire61(timeout time.Duration) []string {
+	return q.expire(timeout, q.blockPendPool, nil)
+}
+
+// ExpireBlocks checks for in flight block body requests that exceeded a timeout
+// allowance, canceling them and returning the responsible peers for penalization.
+func (q *queue) ExpireBlocks(timeout time.Duration) []string {
+	return q.expire(timeout, q.blockPendPool, q.blockTaskQueue)
+}
+
+// ExpireReceipts checks for in flight receipt requests that exceeded a timeout
+// allowance, canceling them and returning the responsible peers for penalization.
+func (q *queue) ExpireReceipts(timeout time.Duration) []string {
+	return q.expire(timeout, q.receiptPendPool, q.receiptTaskQueue)
+}
+
+// expire is the generic check that move expired tasks from a pending pool back
+// into a task pool, returning all entities caught with expired tasks.
+func (q *queue) expire(timeout time.Duration, pendPool map[string]*fetchRequest, taskQueue *prque.Prque) []string {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
 	// Iterate over the expired requests and return each to the queue
 	peers := []string{}
-	for id, request := range q.pendPool {
+	for id, request := range pendPool {
 		if time.Since(request.Time) > timeout {
 			// Update the metrics with the timeout
 			if len(request.Hashes) > 0 {
@@ -421,14 +550,14 @@ func (q *queue) Expire(timeout time.Duration) []string {
 				q.hashQueue.Push(hash, float32(index))
 			}
 			for _, header := range request.Headers {
-				q.headerQueue.Push(header, -float32(header.Number.Uint64()))
+				taskQueue.Push(header, -float32(header.Number.Uint64()))
 			}
 			peers = append(peers, id)
 		}
 	}
 	// Remove the expired requests from the pending pool
 	for _, id := range peers {
-		delete(q.pendPool, id)
+		delete(pendPool, id)
 	}
 	return peers
 }
@@ -439,12 +568,12 @@ func (q *queue) Deliver61(id string, blocks []*types.Block) (err error) {
 	defer q.lock.Unlock()
 
 	// Short circuit if the blocks were never requested
-	request := q.pendPool[id]
+	request := q.blockPendPool[id]
 	if request == nil {
 		return errNoFetchesPending
 	}
 	blockReqTimer.UpdateSince(request.Time)
-	delete(q.pendPool, id)
+	delete(q.blockPendPool, id)
 
 	// If no blocks were retrieved, mark them as unavailable for the origin peer
 	if len(blocks) == 0 {
@@ -461,10 +590,19 @@ func (q *queue) Deliver61(id string, blocks []*types.Block) (err error) {
 			errs = append(errs, fmt.Errorf("non-requested block %x", hash))
 			continue
 		}
-		// Queue the block up for processing
-		if err := q.enqueue(id, block); err != nil {
-			return err
+		// Reconstruct the next result if contents match up
+		index := int(block.Number().Int64() - int64(q.resultOffset))
+		if index >= len(q.resultCache) || index < 0 {
+			errs = []error{errInvalidChain}
+			break
+		}
+		q.resultCache[index] = &fetchResult{
+			Header:       block.Header(),
+			Transactions: block.Transactions(),
+			Uncles:       block.Uncles(),
 		}
+		q.blockDonePool[block.Hash()] = struct{}{}
+
 		delete(request.Hashes, hash)
 		delete(q.hashPool, hash)
 	}
@@ -473,60 +611,94 @@ func (q *queue) Deliver61(id string, blocks []*types.Block) (err error) {
 		q.hashQueue.Push(hash, float32(index))
 	}
 	// If none of the blocks were good, it's a stale delivery
-	if len(errs) != 0 {
-		if len(errs) == len(blocks) {
-			return errStaleDelivery
-		}
+	switch {
+	case len(errs) == 0:
+		return nil
+
+	case len(errs) == 1 && (errs[0] == errInvalidChain || errs[0] == errInvalidBlock):
+		return errs[0]
+
+	case len(errs) == len(request.Headers):
+		return errStaleDelivery
+
+	default:
 		return fmt.Errorf("multiple failures: %v", errs)
 	}
-	return nil
 }
 
-// Deliver injects a block body retrieval response into the download queue.
-func (q *queue) Deliver(id string, txLists [][]*types.Transaction, uncleLists [][]*types.Header) error {
+// DeliverBlocks injects a block (body) retrieval response into the results queue.
+func (q *queue) DeliverBlocks(id string, txLists [][]*types.Transaction, uncleLists [][]*types.Header) error {
+	reconstruct := func(header *types.Header, index int, result *fetchResult) error {
+		if types.DeriveSha(types.Transactions(txLists[index])) != header.TxHash || types.CalcUncleHash(uncleLists[index]) != header.UncleHash {
+			return errInvalidBody
+		}
+		result.Transactions = txLists[index]
+		result.Uncles = uncleLists[index]
+		return nil
+	}
+	return q.deliver(id, q.blockTaskPool, q.blockTaskQueue, q.blockPendPool, q.blockDonePool, bodyReqTimer, len(txLists), reconstruct)
+}
+
+// DeliverReceipts injects a receipt retrieval response into the results queue.
+func (q *queue) DeliverReceipts(id string, receiptList [][]*types.Receipt) error {
+	reconstruct := func(header *types.Header, index int, result *fetchResult) error {
+		if types.DeriveSha(types.Receipts(receiptList[index])) != header.ReceiptHash {
+			return errInvalidReceipt
+		}
+		result.Receipts = receiptList[index]
+		return nil
+	}
+	return q.deliver(id, q.receiptTaskPool, q.receiptTaskQueue, q.receiptPendPool, q.receiptDonePool, receiptReqTimer, len(receiptList), reconstruct)
+}
+
+// deliver injects a data retrieval response into the results queue.
+func (q *queue) deliver(id string, taskPool map[common.Hash]*types.Header, taskQueue *prque.Prque, pendPool map[string]*fetchRequest,
+	donePool map[common.Hash]struct{}, reqTimer metrics.Timer, results int, reconstruct func(header *types.Header, index int, result *fetchResult) error) error {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
-	// Short circuit if the block bodies were never requested
-	request := q.pendPool[id]
+	// Short circuit if the data was never requested
+	request := pendPool[id]
 	if request == nil {
 		return errNoFetchesPending
 	}
-	bodyReqTimer.UpdateSince(request.Time)
-	delete(q.pendPool, id)
+	reqTimer.UpdateSince(request.Time)
+	delete(pendPool, id)
 
-	// If no block bodies were retrieved, mark them as unavailable for the origin peer
-	if len(txLists) == 0 || len(uncleLists) == 0 {
+	// If no data items were retrieved, mark them as unavailable for the origin peer
+	if results == 0 {
 		for hash, _ := range request.Headers {
 			request.Peer.ignored.Add(hash)
 		}
 	}
-	// Assemble each of the block bodies with their headers and queue for processing
+	// Assemble each of the results with their headers and retrieved data parts
 	errs := make([]error, 0)
 	for i, header := range request.Headers {
-		// Short circuit block assembly if no more bodies are found
-		if i >= len(txLists) || i >= len(uncleLists) {
+		// Short circuit assembly if no more fetch results are found
+		if i >= results {
 			break
 		}
-		// Reconstruct the next block if contents match up
-		if types.DeriveSha(types.Transactions(txLists[i])) != header.TxHash || types.CalcUncleHash(uncleLists[i]) != header.UncleHash {
-			errs = []error{errInvalidBody}
+		// Reconstruct the next result if contents match up
+		index := int(header.Number.Int64() - int64(q.resultOffset))
+		if index >= len(q.resultCache) || index < 0 || q.resultCache[index] == nil {
+			errs = []error{errInvalidChain}
 			break
 		}
-		block := types.NewBlockWithHeader(header).WithBody(txLists[i], uncleLists[i])
-
-		// Queue the block up for processing
-		if err := q.enqueue(id, block); err != nil {
+		if err := reconstruct(header, i, q.resultCache[index]); err != nil {
 			errs = []error{err}
 			break
 		}
+		donePool[header.Hash()] = struct{}{}
+		q.resultCache[index].Pending--
+
+		// Clean up a successful fetch
 		request.Headers[i] = nil
-		delete(q.headerPool, header.Hash())
+		delete(taskPool, header.Hash())
 	}
 	// Return all failed or missing fetches to the queue
 	for _, header := range request.Headers {
 		if header != nil {
-			q.headerQueue.Push(header, -float32(header.Number.Uint64()))
+			taskQueue.Push(header, -float32(header.Number.Uint64()))
 		}
 	}
 	// If none of the blocks were good, it's a stale delivery
@@ -534,11 +706,8 @@ func (q *queue) Deliver(id string, txLists [][]*types.Transaction, uncleLists []
 	case len(errs) == 0:
 		return nil
 
-	case len(errs) == 1 && errs[0] == errInvalidBody:
-		return errInvalidBody
-
-	case len(errs) == 1 && errs[0] == errInvalidChain:
-		return errInvalidChain
+	case len(errs) == 1 && (errs[0] == errInvalidChain || errs[0] == errInvalidBody || errs[0] == errInvalidReceipt):
+		return errs[0]
 
 	case len(errs) == len(request.Headers):
 		return errStaleDelivery
@@ -548,29 +717,14 @@ func (q *queue) Deliver(id string, txLists [][]*types.Transaction, uncleLists []
 	}
 }
 
-// enqueue inserts a new block into the final delivery queue, waiting for pickup
-// by the processor.
-func (q *queue) enqueue(origin string, block *types.Block) error {
-	// If a requested block falls out of the range, the hash chain is invalid
-	index := int(int64(block.NumberU64()) - int64(q.blockOffset))
-	if index >= len(q.blockCache) || index < 0 {
-		return errInvalidChain
-	}
-	// Otherwise merge the block and mark the hash done
-	q.blockCache[index] = &Block{
-		RawBlock:   block,
-		OriginPeer: origin,
-	}
-	q.blockPool[block.Header().Hash()] = block.NumberU64()
-	return nil
-}
-
-// Prepare configures the block cache offset to allow accepting inbound blocks.
-func (q *queue) Prepare(offset uint64) {
+// Prepare configures the result cache to allow accepting and caching inbound
+// fetch results.
+func (q *queue) Prepare(offset uint64, parts int) {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
-	if q.blockOffset < offset {
-		q.blockOffset = offset
+	if q.resultOffset < offset {
+		q.resultOffset = offset
 	}
+	q.resultParts = parts
 }

eth/handler.go

@@ -120,15 +120,25 @@ func NewProtocolManager(mode Mode, networkId int, mux *event.TypeMux, txpool txP
 		return nil, errIncompatibleConfig
 	}
 	// Construct the different synchronisation mechanisms
-	manager.downloader = downloader.New(manager.eventMux, manager.blockchain.HasBlock, manager.blockchain.GetBlock, manager.blockchain.CurrentBlock, manager.blockchain.GetTd, manager.blockchain.InsertChain, manager.removePeer)
+	var syncMode downloader.SyncMode
+	switch mode {
+	case ArchiveMode:
+		syncMode = downloader.FullSync
+	case FullMode:
+		syncMode = downloader.FastSync
+	case LightMode:
+		syncMode = downloader.LightSync
+	}
+	manager.downloader = downloader.New(syncMode, manager.eventMux, blockchain.HasHeader, blockchain.HasBlock, blockchain.GetHeader, blockchain.GetBlock,
+		blockchain.CurrentHeader, blockchain.CurrentBlock, blockchain.GetTd, blockchain.InsertHeaderChain, blockchain.InsertChain, nil, manager.removePeer)
 
 	validator := func(block *types.Block, parent *types.Block) error {
 		return core.ValidateHeader(pow, block.Header(), parent.Header(), true, false)
 	}
 	heighter := func() uint64 {
-		return manager.blockchain.CurrentBlock().NumberU64()
+		return blockchain.CurrentBlock().NumberU64()
 	}
-	manager.fetcher = fetcher.New(manager.blockchain.GetBlock, validator, manager.BroadcastBlock, heighter, manager.blockchain.InsertChain, manager.removePeer)
+	manager.fetcher = fetcher.New(blockchain.GetBlock, validator, manager.BroadcastBlock, heighter, blockchain.InsertChain, manager.removePeer)
 
 	return manager, nil
 }
@@ -210,7 +220,7 @@ func (pm *ProtocolManager) handle(p *peer) error {
 	// Register the peer in the downloader. If the downloader considers it banned, we disconnect
 	if err := pm.downloader.RegisterPeer(p.id, p.version, p.Head(),
 		p.RequestHashes, p.RequestHashesFromNumber, p.RequestBlocks,
-		p.RequestHeadersByHash, p.RequestHeadersByNumber, p.RequestBodies); err != nil {
+		p.RequestHeadersByHash, p.RequestHeadersByNumber, p.RequestBodies, p.RequestReceipts); err != nil {
 		return err
 	}
 	// Propagate existing transactions. new transactions appearing
@@ -514,22 +524,31 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		var (
 			hash     common.Hash
 			bytes    int
-			receipts []*types.Receipt
+			receipts []rlp.RawValue
 		)
-		for bytes < softResponseLimit && len(receipts) < downloader.MaxReceiptsFetch {
-			// Retrieve the hash of the next transaction receipt
+		for bytes < softResponseLimit && len(receipts) < downloader.MaxReceiptFetch {
+			// Retrieve the hash of the next block
 			if err := msgStream.Decode(&hash); err == rlp.EOL {
 				break
 			} else if err != nil {
 				return errResp(ErrDecode, "msg %v: %v", msg, err)
 			}
-			// Retrieve the requested receipt, stopping if enough was found
-			if receipt := core.GetReceipt(pm.chaindb, hash); receipt != nil {
-				receipts = append(receipts, receipt)
-				bytes += len(receipt.RlpEncode())
+			// Retrieve the requested block's receipts, skipping if unknown to us
+			results := core.GetBlockReceipts(pm.chaindb, hash)
+			if results == nil {
+				if header := pm.blockchain.GetHeader(hash); header == nil || header.ReceiptHash != types.EmptyRootHash {
+					continue
+				}
+			}
+			// If known, encode and queue for response packet
+			if encoded, err := rlp.EncodeToBytes(results); err != nil {
+				glog.V(logger.Error).Infof("failed to encode receipt: %v", err)
+			} else {
+				receipts = append(receipts, encoded)
+				bytes += len(encoded)
 			}
 		}
-		return p.SendReceipts(receipts)
+		return p.SendReceiptsRLP(receipts)
 
 	case msg.Code == NewBlockHashesMsg:
 		// Retrieve and deseralize the remote new block hashes notification

eth/handler_test.go

@@ -535,15 +535,12 @@ func testGetReceipt(t *testing.T, protocol int) {
 	defer peer.close()
 
 	// Collect the hashes to request, and the response to expect
-	hashes := []common.Hash{}
+	hashes, receipts := []common.Hash{}, []types.Receipts{}
 	for i := uint64(0); i <= pm.blockchain.CurrentBlock().NumberU64(); i++ {
-		for _, tx := range pm.blockchain.GetBlockByNumber(i).Transactions() {
-			hashes = append(hashes, tx.Hash())
-		}
-	}
-	receipts := make([]*types.Receipt, len(hashes))
-	for i, hash := range hashes {
-		receipts[i] = core.GetReceipt(pm.chaindb, hash)
+		block := pm.blockchain.GetBlockByNumber(i)
+
+		hashes = append(hashes, block.Hash())
+		receipts = append(receipts, core.GetBlockReceipts(pm.chaindb, block.Hash()))
 	}
 	// Send the hash request and verify the response
 	p2p.Send(peer.app, 0x0f, hashes)

eth/peer.go

@@ -197,9 +197,9 @@ func (p *peer) SendNodeData(data [][]byte) error {
 	return p2p.Send(p.rw, NodeDataMsg, data)
 }
 
-// SendReceipts sends a batch of transaction receipts, corresponding to the ones
-// requested.
-func (p *peer) SendReceipts(receipts []*types.Receipt) error {
+// SendReceiptsRLP sends a batch of transaction receipts, corresponding to the
+// ones requested from an already RLP encoded format.
+func (p *peer) SendReceiptsRLP(receipts []rlp.RawValue) error {
 	return p2p.Send(p.rw, ReceiptsMsg, receipts)
 }