all: integrate the freezer with fast sync

* all: freezer style syncing

core, eth, les, light: clean up freezer relative APIs

core, eth, les, trie, ethdb, light: clean a bit

core, eth, les, light: add unit tests

core, light: rewrite setHead function

core, eth: fix downloader unit tests

core: add receipt chain insertion test

core: use constant instead of hardcoding table name

core: fix rollback

core: fix setHead

core/rawdb: remove canonical block first and then iterate side chain

core/rawdb, ethdb: add hasAncient interface

eth/downloader: calculate ancient limit via cht first

core, eth, ethdb: lots of fixes

* eth/downloader: print ancient disable log only for fast sync

core/headerchain.go

@@ -453,33 +453,56 @@ func (hc *HeaderChain) SetCurrentHeader(head *types.Header) {
 	hc.currentHeaderHash = head.Hash()
 }
 
-// DeleteCallback is a callback function that is called by SetHead before
-// each header is deleted.
-type DeleteCallback func(ethdb.Writer, common.Hash, uint64)
+type (
+	// UpdateHeadBlocksCallback is a callback function that is called by SetHead
+	// before head header is updated.
+	UpdateHeadBlocksCallback func(ethdb.KeyValueWriter, *types.Header)
+
+	// DeleteBlockContentCallback is a callback function that is called by SetHead
+	// before each header is deleted.
+	DeleteBlockContentCallback func(ethdb.KeyValueWriter, common.Hash, uint64)
+)
 
 // SetHead rewinds the local chain to a new head. Everything above the new head
 // will be deleted and the new one set.
-func (hc *HeaderChain) SetHead(head uint64, delFn DeleteCallback) {
-	height := uint64(0)
-
-	if hdr := hc.CurrentHeader(); hdr != nil {
-		height = hdr.Number.Uint64()
-	}
-	batch := hc.chainDb.NewBatch()
+func (hc *HeaderChain) SetHead(head uint64, updateFn UpdateHeadBlocksCallback, delFn DeleteBlockContentCallback) {
+	var (
+		parentHash common.Hash
+		batch      = hc.chainDb.NewBatch()
+	)
 	for hdr := hc.CurrentHeader(); hdr != nil && hdr.Number.Uint64() > head; hdr = hc.CurrentHeader() {
-		hash := hdr.Hash()
-		num := hdr.Number.Uint64()
+		hash, num := hdr.Hash(), hdr.Number.Uint64()
+
+		// Rewind block chain to new head.
+		parent := hc.GetHeader(hdr.ParentHash, num-1)
+		if parent == nil {
+			parent = hc.genesisHeader
+		}
+		parentHash = hdr.ParentHash
+		// Notably, since geth has the possibility for setting the head to a low
+		// height which is even lower than ancient head.
+		// In order to ensure that the head is always no higher than the data in
+		// the database(ancient store or active store), we need to update head
+		// first then remove the relative data from the database.
+		//
+		// Update head first(head fast block, head full block) before deleting the data.
+		if updateFn != nil {
+			updateFn(hc.chainDb, parent)
+		}
+		// Update head header then.
+		rawdb.WriteHeadHeaderHash(hc.chainDb, parentHash)
+
+		// Remove the relative data from the database.
 		if delFn != nil {
 			delFn(batch, hash, num)
 		}
+		// Rewind header chain to new head.
 		rawdb.DeleteHeader(batch, hash, num)
 		rawdb.DeleteTd(batch, hash, num)
+		rawdb.DeleteCanonicalHash(batch, num)
 
-		hc.currentHeader.Store(hc.GetHeader(hdr.ParentHash, hdr.Number.Uint64()-1))
-	}
-	// Roll back the canonical chain numbering
-	for i := height; i > head; i-- {
-		rawdb.DeleteCanonicalHash(batch, i)
+		hc.currentHeader.Store(parent)
+		hc.currentHeaderHash = parentHash
 	}
 	batch.Write()
 
@@ -487,13 +510,6 @@ func (hc *HeaderChain) SetHead(head uint64, delFn DeleteCallback) {
 	hc.headerCache.Purge()
 	hc.tdCache.Purge()
 	hc.numberCache.Purge()
-
-	if hc.CurrentHeader() == nil {
-		hc.currentHeader.Store(hc.genesisHeader)
-	}
-	hc.currentHeaderHash = hc.CurrentHeader().Hash()
-
-	rawdb.WriteHeadHeaderHash(hc.chainDb, hc.currentHeaderHash)
 }
 
 // SetGenesis sets a new genesis block header for the chain

core/rawdb/accessors_indexes.go

@@ -54,7 +54,7 @@ func ReadTxLookupEntry(db ethdb.Reader, hash common.Hash) *uint64 {
 
 // WriteTxLookupEntries stores a positional metadata for every transaction from
 // a block, enabling hash based transaction and receipt lookups.
-func WriteTxLookupEntries(db ethdb.Writer, block *types.Block) {
+func WriteTxLookupEntries(db ethdb.KeyValueWriter, block *types.Block) {
 	for _, tx := range block.Transactions() {
 		if err := db.Put(txLookupKey(tx.Hash()), block.Number().Bytes()); err != nil {
 			log.Crit("Failed to store transaction lookup entry", "err", err)
@@ -63,13 +63,13 @@ func WriteTxLookupEntries(db ethdb.Writer, block *types.Block) {
 }
 
 // DeleteTxLookupEntry removes all transaction data associated with a hash.
-func DeleteTxLookupEntry(db ethdb.Writer, hash common.Hash) {
+func DeleteTxLookupEntry(db ethdb.KeyValueWriter, hash common.Hash) {
 	db.Delete(txLookupKey(hash))
 }
 
 // ReadTransaction retrieves a specific transaction from the database, along with
 // its added positional metadata.
-func ReadTransaction(db ethdb.AncientReader, hash common.Hash) (*types.Transaction, common.Hash, uint64, uint64) {
+func ReadTransaction(db ethdb.Reader, hash common.Hash) (*types.Transaction, common.Hash, uint64, uint64) {
 	blockNumber := ReadTxLookupEntry(db, hash)
 	if blockNumber == nil {
 		return nil, common.Hash{}, 0, 0
@@ -94,7 +94,7 @@ func ReadTransaction(db ethdb.AncientReader, hash common.Hash) (*types.Transacti
 
 // ReadReceipt retrieves a specific transaction receipt from the database, along with
 // its added positional metadata.
-func ReadReceipt(db ethdb.AncientReader, hash common.Hash, config *params.ChainConfig) (*types.Receipt, common.Hash, uint64, uint64) {
+func ReadReceipt(db ethdb.Reader, hash common.Hash, config *params.ChainConfig) (*types.Receipt, common.Hash, uint64, uint64) {
 	// Retrieve the context of the receipt based on the transaction hash
 	blockNumber := ReadTxLookupEntry(db, hash)
 	if blockNumber == nil {
@@ -117,13 +117,13 @@ func ReadReceipt(db ethdb.AncientReader, hash common.Hash, config *params.ChainC
 
 // ReadBloomBits retrieves the compressed bloom bit vector belonging to the given
 // section and bit index from the.
-func ReadBloomBits(db ethdb.Reader, bit uint, section uint64, head common.Hash) ([]byte, error) {
+func ReadBloomBits(db ethdb.KeyValueReader, bit uint, section uint64, head common.Hash) ([]byte, error) {
 	return db.Get(bloomBitsKey(bit, section, head))
 }
 
 // WriteBloomBits stores the compressed bloom bits vector belonging to the given
 // section and bit index.
-func WriteBloomBits(db ethdb.Writer, bit uint, section uint64, head common.Hash, bits []byte) {
+func WriteBloomBits(db ethdb.KeyValueWriter, bit uint, section uint64, head common.Hash, bits []byte) {
 	if err := db.Put(bloomBitsKey(bit, section, head), bits); err != nil {
 		log.Crit("Failed to store bloom bits", "err", err)
 	}

core/rawdb/accessors_metadata.go

@@ -27,7 +27,7 @@ import (
 )
 
 // ReadDatabaseVersion retrieves the version number of the database.
-func ReadDatabaseVersion(db ethdb.Reader) *uint64 {
+func ReadDatabaseVersion(db ethdb.KeyValueReader) *uint64 {
 	var version uint64
 
 	enc, _ := db.Get(databaseVerisionKey)
@@ -42,7 +42,7 @@ func ReadDatabaseVersion(db ethdb.Reader) *uint64 {
 }
 
 // WriteDatabaseVersion stores the version number of the database
-func WriteDatabaseVersion(db ethdb.Writer, version uint64) {
+func WriteDatabaseVersion(db ethdb.KeyValueWriter, version uint64) {
 	enc, err := rlp.EncodeToBytes(version)
 	if err != nil {
 		log.Crit("Failed to encode database version", "err", err)
@@ -53,7 +53,7 @@ func WriteDatabaseVersion(db ethdb.Writer, version uint64) {
 }
 
 // ReadChainConfig retrieves the consensus settings based on the given genesis hash.
-func ReadChainConfig(db ethdb.Reader, hash common.Hash) *params.ChainConfig {
+func ReadChainConfig(db ethdb.KeyValueReader, hash common.Hash) *params.ChainConfig {
 	data, _ := db.Get(configKey(hash))
 	if len(data) == 0 {
 		return nil
@@ -67,7 +67,7 @@ func ReadChainConfig(db ethdb.Reader, hash common.Hash) *params.ChainConfig {
 }
 
 // WriteChainConfig writes the chain config settings to the database.
-func WriteChainConfig(db ethdb.Writer, hash common.Hash, cfg *params.ChainConfig) {
+func WriteChainConfig(db ethdb.KeyValueWriter, hash common.Hash, cfg *params.ChainConfig) {
 	if cfg == nil {
 		return
 	}
@@ -81,13 +81,13 @@ func WriteChainConfig(db ethdb.Writer, hash common.Hash, cfg *params.ChainConfig
 }
 
 // ReadPreimage retrieves a single preimage of the provided hash.
-func ReadPreimage(db ethdb.Reader, hash common.Hash) []byte {
+func ReadPreimage(db ethdb.KeyValueReader, hash common.Hash) []byte {
 	data, _ := db.Get(preimageKey(hash))
 	return data
 }
 
 // WritePreimages writes the provided set of preimages to the database.
-func WritePreimages(db ethdb.Writer, preimages map[common.Hash][]byte) {
+func WritePreimages(db ethdb.KeyValueWriter, preimages map[common.Hash][]byte) {
 	for hash, preimage := range preimages {
 		if err := db.Put(preimageKey(hash), preimage); err != nil {
 			log.Crit("Failed to store trie preimage", "err", err)

core/rawdb/database.go

@@ -24,7 +24,7 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb/memorydb"
 )
 
-// freezerdb is a databse wrapper that enabled freezer data retrievals.
+// freezerdb is a database wrapper that enabled freezer data retrievals.
 type freezerdb struct {
 	ethdb.KeyValueStore
 	ethdb.AncientStore
@@ -51,9 +51,34 @@ type nofreezedb struct {
 	ethdb.KeyValueStore
 }
 
-// Frozen returns nil as we don't have a backing chain freezer.
+// HasAncient returns an error as we don't have a backing chain freezer.
+func (db *nofreezedb) HasAncient(kind string, number uint64) (bool, error) {
+	return false, errNotSupported
+}
+
+// Ancient returns an error as we don't have a backing chain freezer.
 func (db *nofreezedb) Ancient(kind string, number uint64) ([]byte, error) {
-	return nil, errOutOfBounds
+	return nil, errNotSupported
+}
+
+// Ancients returns an error as we don't have a backing chain freezer.
+func (db *nofreezedb) Ancients() (uint64, error) {
+	return 0, errNotSupported
+}
+
+// AppendAncient returns an error as we don't have a backing chain freezer.
+func (db *nofreezedb) AppendAncient(number uint64, hash, header, body, receipts, td []byte) error {
+	return errNotSupported
+}
+
+// TruncateAncients returns an error as we don't have a backing chain freezer.
+func (db *nofreezedb) TruncateAncients(items uint64) error {
+	return errNotSupported
+}
+
+// Sync returns an error as we don't have a backing chain freezer.
+func (db *nofreezedb) Sync() error {
+	return errNotSupported
 }
 
 // NewDatabase creates a high level database on top of a given key-value data

core/rawdb/freezer_table.go

@@ -39,6 +39,9 @@ var (
 	// errOutOfBounds is returned if the item requested is not contained within the
 	// freezer table.
 	errOutOfBounds = errors.New("out of bounds")
+
+	// errNotSupported is returned if the database doesn't support the required operation.
+	errNotSupported = errors.New("this operation is not supported")
 )
 
 // indexEntry contains the number/id of the file that the data resides in, aswell as the
@@ -451,7 +454,6 @@ func (t *freezerTable) getBounds(item uint64) (uint32, uint32, uint32, error) {
 // Retrieve looks up the data offset of an item with the given number and retrieves
 // the raw binary blob from the data file.
 func (t *freezerTable) Retrieve(item uint64) ([]byte, error) {
-
 	// Ensure the table and the item is accessible
 	if t.index == nil || t.head == nil {
 		return nil, errClosed
@@ -483,6 +485,12 @@ func (t *freezerTable) Retrieve(item uint64) ([]byte, error) {
 	return snappy.Decode(nil, blob)
 }
 
+// has returns an indicator whether the specified number data
+// exists in the freezer table.
+func (t *freezerTable) has(number uint64) bool {
+	return atomic.LoadUint64(&t.items) > number
+}
+
 // Sync pushes any pending data from memory out to disk. This is an expensive
 // operation, so use it with care.
 func (t *freezerTable) Sync() error {

core/rawdb/schema.go

@@ -63,6 +63,23 @@ var (
 	preimageHitCounter = metrics.NewRegisteredCounter("db/preimage/hits", nil)
 )
 
+const (
+	// freezerHeaderTable indicates the name of the freezer header table.
+	freezerHeaderTable = "headers"
+
+	// freezerHashTable indicates the name of the freezer canonical hash table.
+	freezerHashTable = "hashes"
+
+	// freezerBodiesTable indicates the name of the freezer block body table.
+	freezerBodiesTable = "bodies"
+
+	// freezerReceiptTable indicates the name of the freezer receipts table.
+	freezerReceiptTable = "receipts"
+
+	// freezerDifficultyTable indicates the name of the freezer total difficulty table.
+	freezerDifficultyTable = "diffs"
+)
+
 // LegacyTxLookupEntry is the legacy TxLookupEntry definition with some unnecessary
 // fields.
 type LegacyTxLookupEntry struct {

core/rawdb/table.go

@@ -50,12 +50,42 @@ func (t *table) Get(key []byte) ([]byte, error) {
 	return t.db.Get(append([]byte(t.prefix), key...))
 }
 
+// HasAncient is a noop passthrough that just forwards the request to the underlying
+// database.
+func (t *table) HasAncient(kind string, number uint64) (bool, error) {
+	return t.db.HasAncient(kind, number)
+}
+
 // Ancient is a noop passthrough that just forwards the request to the underlying
 // database.
 func (t *table) Ancient(kind string, number uint64) ([]byte, error) {
 	return t.db.Ancient(kind, number)
 }
 
+// Ancients is a noop passthrough that just forwards the request to the underlying
+// database.
+func (t *table) Ancients() (uint64, error) {
+	return t.db.Ancients()
+}
+
+// AppendAncient is a noop passthrough that just forwards the request to the underlying
+// database.
+func (t *table) AppendAncient(number uint64, hash, header, body, receipts, td []byte) error {
+	return t.db.AppendAncient(number, hash, header, body, receipts, td)
+}
+
+// TruncateAncients is a noop passthrough that just forwards the request to the underlying
+// database.
+func (t *table) TruncateAncients(items uint64) error {
+	return t.db.TruncateAncients(items)
+}
+
+// Sync is a noop passthrough that just forwards the request to the underlying
+// database.
+func (t *table) Sync() error {
+	return t.db.Sync()
+}
+
 // Put inserts the given value into the database at a prefixed version of the
 // provided key.
 func (t *table) Put(key []byte, value []byte) error {
@@ -163,6 +193,6 @@ func (b *tableBatch) Reset() {
 }
 
 // Replay replays the batch contents.
-func (b *tableBatch) Replay(w ethdb.Writer) error {
+func (b *tableBatch) Replay(w ethdb.KeyValueWriter) error {
 	return b.batch.Replay(w)
 }

core/state/database.go

@@ -93,7 +93,7 @@ type Trie interface {
 	// If the trie does not contain a value for key, the returned proof contains all
 	// nodes of the longest existing prefix of the key (at least the root), ending
 	// with the node that proves the absence of the key.
-	Prove(key []byte, fromLevel uint, proofDb ethdb.Writer) error
+	Prove(key []byte, fromLevel uint, proofDb ethdb.KeyValueWriter) error
 }
 
 // NewDatabase creates a backing store for state. The returned database is safe for

core/state/sync.go

@@ -26,7 +26,7 @@ import (
 )
 
 // NewStateSync create a new state trie download scheduler.
-func NewStateSync(root common.Hash, database ethdb.Reader, bloom *trie.SyncBloom) *trie.Sync {
+func NewStateSync(root common.Hash, database ethdb.KeyValueReader, bloom *trie.SyncBloom) *trie.Sync {
 	var syncer *trie.Sync
 	callback := func(leaf []byte, parent common.Hash) error {
 		var obj Account

eth/downloader/downloader.go

@@ -129,6 +129,7 @@ type Downloader struct {
 	synchronising   int32
 	notified        int32
 	committed       int32
+	ancientLimit    uint64 // The maximum block number which can be regarded as ancient data.
 
 	// Channels
 	headerCh      chan dataPack        // [eth/62] Channel receiving inbound block headers
@@ -206,7 +207,7 @@ type BlockChain interface {
 	InsertChain(types.Blocks) (int, error)
 
 	// InsertReceiptChain inserts a batch of receipts into the local chain.
-	InsertReceiptChain(types.Blocks, []types.Receipts) (int, error)
+	InsertReceiptChain(types.Blocks, []types.Receipts, uint64) (int, error)
 }
 
 // New creates a new downloader to fetch hashes and blocks from remote peers.
@@ -475,12 +476,49 @@ func (d *Downloader) syncWithPeer(p *peerConnection, hash common.Hash, td *big.I
 	if d.mode == FastSync && pivot != 0 {
 		d.committed = 0
 	}
+	if d.mode == FastSync {
+		// Set the ancient data limitation.
+		// If we are running fast sync, all block data not greater than ancientLimit will
+		// be written to the ancient store. Otherwise, block data will be written to active
+		// database and then wait freezer to migrate.
+		//
+		// If there is checkpoint available, then calculate the ancientLimit through
+		// checkpoint. Otherwise calculate the ancient limit through the advertised
+		// height by remote peer.
+		//
+		// The reason for picking checkpoint first is: there exists an attack vector
+		// for height that: a malicious peer can give us a fake(very high) height,
+		// so that the ancient limit is also very high. And then the peer start to
+		// feed us valid blocks until head. All of these blocks might be written into
+		// the ancient store, the safe region for freezer is not enough.
+		if d.checkpoint != 0 && d.checkpoint > MaxForkAncestry+1 {
+			d.ancientLimit = height - MaxForkAncestry - 1
+		} else if height > MaxForkAncestry+1 {
+			d.ancientLimit = height - MaxForkAncestry - 1
+		}
+		frozen, _ := d.stateDB.Ancients() // Ignore the error here since light client can also hit here.
+		// If a part of blockchain data has already been written into active store,
+		// disable the ancient style insertion explicitly.
+		if origin >= frozen && frozen != 0 {
+			d.ancientLimit = 0
+			log.Info("Disabling direct-ancient mode", "origin", origin, "ancient", frozen-1)
+		} else if d.ancientLimit > 0 {
+			log.Debug("Enabling direct-ancient mode", "ancient", d.ancientLimit)
+		}
+		// Rewind the ancient store and blockchain if reorg happens.
+		if origin+1 < frozen {
+			var hashes []common.Hash
+			for i := origin + 1; i < d.lightchain.CurrentHeader().Number.Uint64(); i++ {
+				hashes = append(hashes, rawdb.ReadCanonicalHash(d.stateDB, i))
+			}
+			d.lightchain.Rollback(hashes)
+		}
+	}
 	// Initiate the sync using a concurrent header and content retrieval algorithm
 	d.queue.Prepare(origin+1, d.mode)
 	if d.syncInitHook != nil {
 		d.syncInitHook(origin, height)
 	}
-
 	fetchers := []func() error{
 		func() error { return d.fetchHeaders(p, origin+1, pivot) }, // Headers are always retrieved
 		func() error { return d.fetchBodies(origin + 1) },          // Bodies are retrieved during normal and fast sync
@@ -544,6 +582,9 @@ func (d *Downloader) cancel() {
 func (d *Downloader) Cancel() {
 	d.cancel()
 	d.cancelWg.Wait()
+
+	d.ancientLimit = 0
+	log.Debug("Reset ancient limit to zero")
 }
 
 // Terminate interrupts the downloader, canceling all pending operations.
@@ -1315,7 +1356,7 @@ func (d *Downloader) fetchParts(errCancel error, deliveryCh chan dataPack, deliv
 // queue until the stream ends or a failure occurs.
 func (d *Downloader) processHeaders(origin uint64, pivot uint64, td *big.Int) error {
 	// Keep a count of uncertain headers to roll back
-	rollback := []*types.Header{}
+	var rollback []*types.Header
 	defer func() {
 		if len(rollback) > 0 {
 			// Flatten the headers and roll them back
@@ -1409,11 +1450,10 @@ func (d *Downloader) processHeaders(origin uint64, pivot uint64, td *big.Int) er
 					limit = len(headers)
 				}
 				chunk := headers[:limit]
-
 				// In case of header only syncing, validate the chunk immediately
 				if d.mode == FastSync || d.mode == LightSync {
 					// Collect the yet unknown headers to mark them as uncertain
-					unknown := make([]*types.Header, 0, len(headers))
+					unknown := make([]*types.Header, 0, len(chunk))
 					for _, header := range chunk {
 						if !d.lightchain.HasHeader(header.Hash(), header.Number.Uint64()) {
 							unknown = append(unknown, header)
@@ -1663,7 +1703,7 @@ func (d *Downloader) commitFastSyncData(results []*fetchResult, stateSync *state
 		blocks[i] = types.NewBlockWithHeader(result.Header).WithBody(result.Transactions, result.Uncles)
 		receipts[i] = result.Receipts
 	}
-	if index, err := d.blockchain.InsertReceiptChain(blocks, receipts); err != nil {
+	if index, err := d.blockchain.InsertReceiptChain(blocks, receipts, d.ancientLimit); err != nil {
 		log.Debug("Downloaded item processing failed", "number", results[index].Header.Number, "hash", results[index].Header.Hash(), "err", err)
 		return errInvalidChain
 	}
@@ -1675,7 +1715,7 @@ func (d *Downloader) commitPivotBlock(result *fetchResult) error {
 	log.Debug("Committing fast sync pivot as new head", "number", block.Number(), "hash", block.Hash())
 
 	// Commit the pivot block as the new head, will require full sync from here on
-	if _, err := d.blockchain.InsertReceiptChain([]*types.Block{block}, []types.Receipts{result.Receipts}); err != nil {
+	if _, err := d.blockchain.InsertReceiptChain([]*types.Block{block}, []types.Receipts{result.Receipts}, d.ancientLimit); err != nil {
 		return err
 	}
 	if err := d.blockchain.FastSyncCommitHead(block.Hash()); err != nil {

eth/downloader/downloader_test.go

@@ -57,6 +57,11 @@ type downloadTester struct {
 	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
 
+	ancientHeaders  map[common.Hash]*types.Header  // Ancient headers belonging to the tester
+	ancientBlocks   map[common.Hash]*types.Block   // Ancient blocks belonging to the tester
+	ancientReceipts map[common.Hash]types.Receipts // Ancient receipts belonging to the tester
+	ancientChainTd  map[common.Hash]*big.Int       // Ancient total difficulties of the blocks in the local chain
+
 	lock sync.RWMutex
 }
 
@@ -71,6 +76,12 @@ func newTester() *downloadTester {
 		ownBlocks:   map[common.Hash]*types.Block{testGenesis.Hash(): testGenesis},
 		ownReceipts: map[common.Hash]types.Receipts{testGenesis.Hash(): nil},
 		ownChainTd:  map[common.Hash]*big.Int{testGenesis.Hash(): testGenesis.Difficulty()},
+
+		// Initialize ancient store with test genesis block
+		ancientHeaders:  map[common.Hash]*types.Header{testGenesis.Hash(): testGenesis.Header()},
+		ancientBlocks:   map[common.Hash]*types.Block{testGenesis.Hash(): testGenesis},
+		ancientReceipts: map[common.Hash]types.Receipts{testGenesis.Hash(): nil},
+		ancientChainTd:  map[common.Hash]*big.Int{testGenesis.Hash(): testGenesis.Difficulty()},
 	}
 	tester.stateDb = rawdb.NewMemoryDatabase()
 	tester.stateDb.Put(testGenesis.Root().Bytes(), []byte{0x00})
@@ -122,6 +133,9 @@ func (dl *downloadTester) HasFastBlock(hash common.Hash, number uint64) bool {
 	dl.lock.RLock()
 	defer dl.lock.RUnlock()
 
+	if _, ok := dl.ancientReceipts[hash]; ok {
+		return true
+	}
 	_, ok := dl.ownReceipts[hash]
 	return ok
 }
@@ -131,6 +145,10 @@ func (dl *downloadTester) GetHeaderByHash(hash common.Hash) *types.Header {
 	dl.lock.RLock()
 	defer dl.lock.RUnlock()
 
+	header := dl.ancientHeaders[hash]
+	if header != nil {
+		return header
+	}
 	return dl.ownHeaders[hash]
 }
 
@@ -139,6 +157,10 @@ func (dl *downloadTester) GetBlockByHash(hash common.Hash) *types.Block {
 	dl.lock.RLock()
 	defer dl.lock.RUnlock()
 
+	block := dl.ancientBlocks[hash]
+	if block != nil {
+		return block
+	}
 	return dl.ownBlocks[hash]
 }
 
@@ -148,6 +170,9 @@ func (dl *downloadTester) CurrentHeader() *types.Header {
 	defer dl.lock.RUnlock()
 
 	for i := len(dl.ownHashes) - 1; i >= 0; i-- {
+		if header := dl.ancientHeaders[dl.ownHashes[i]]; header != nil {
+			return header
+		}
 		if header := dl.ownHeaders[dl.ownHashes[i]]; header != nil {
 			return header
 		}
@@ -161,6 +186,12 @@ func (dl *downloadTester) CurrentBlock() *types.Block {
 	defer dl.lock.RUnlock()
 
 	for i := len(dl.ownHashes) - 1; i >= 0; i-- {
+		if block := dl.ancientBlocks[dl.ownHashes[i]]; block != nil {
+			if _, err := dl.stateDb.Get(block.Root().Bytes()); err == nil {
+				return block
+			}
+			return block
+		}
 		if block := dl.ownBlocks[dl.ownHashes[i]]; block != nil {
 			if _, err := dl.stateDb.Get(block.Root().Bytes()); err == nil {
 				return block
@@ -176,6 +207,9 @@ func (dl *downloadTester) CurrentFastBlock() *types.Block {
 	defer dl.lock.RUnlock()
 
 	for i := len(dl.ownHashes) - 1; i >= 0; i-- {
+		if block := dl.ancientBlocks[dl.ownHashes[i]]; block != nil {
+			return block
+		}
 		if block := dl.ownBlocks[dl.ownHashes[i]]; block != nil {
 			return block
 		}
@@ -198,6 +232,9 @@ func (dl *downloadTester) GetTd(hash common.Hash, number uint64) *big.Int {
 	dl.lock.RLock()
 	defer dl.lock.RUnlock()
 
+	if td := dl.ancientChainTd[hash]; td != nil {
+		return td
+	}
 	return dl.ownChainTd[hash]
 }
 
@@ -254,7 +291,7 @@ func (dl *downloadTester) InsertChain(blocks types.Blocks) (i int, err error) {
 }
 
 // InsertReceiptChain injects a new batch of receipts into the simulated chain.
-func (dl *downloadTester) InsertReceiptChain(blocks types.Blocks, receipts []types.Receipts) (i int, err error) {
+func (dl *downloadTester) InsertReceiptChain(blocks types.Blocks, receipts []types.Receipts, ancientLimit uint64) (i int, err error) {
 	dl.lock.Lock()
 	defer dl.lock.Unlock()
 
@@ -262,11 +299,25 @@ func (dl *downloadTester) InsertReceiptChain(blocks types.Blocks, receipts []typ
 		if _, ok := dl.ownHeaders[blocks[i].Hash()]; !ok {
 			return i, errors.New("unknown owner")
 		}
-		if _, ok := dl.ownBlocks[blocks[i].ParentHash()]; !ok {
-			return i, errors.New("unknown parent")
+		if _, ok := dl.ancientBlocks[blocks[i].ParentHash()]; !ok {
+			if _, ok := dl.ownBlocks[blocks[i].ParentHash()]; !ok {
+				return i, errors.New("unknown parent")
+			}
+		}
+		if blocks[i].NumberU64() <= ancientLimit {
+			dl.ancientBlocks[blocks[i].Hash()] = blocks[i]
+			dl.ancientReceipts[blocks[i].Hash()] = receipts[i]
+
+			// Migrate from active db to ancient db
+			dl.ancientHeaders[blocks[i].Hash()] = blocks[i].Header()
+			dl.ancientChainTd[blocks[i].Hash()] = new(big.Int).Add(dl.ancientChainTd[blocks[i].ParentHash()], blocks[i].Difficulty())
+
+			delete(dl.ownHeaders, blocks[i].Hash())
+			delete(dl.ownChainTd, blocks[i].Hash())
+		} else {
+			dl.ownBlocks[blocks[i].Hash()] = blocks[i]
+			dl.ownReceipts[blocks[i].Hash()] = receipts[i]
 		}
-		dl.ownBlocks[blocks[i].Hash()] = blocks[i]
-		dl.ownReceipts[blocks[i].Hash()] = receipts[i]
 	}
 	return len(blocks), nil
 }
@@ -284,6 +335,11 @@ func (dl *downloadTester) Rollback(hashes []common.Hash) {
 		delete(dl.ownHeaders, hashes[i])
 		delete(dl.ownReceipts, hashes[i])
 		delete(dl.ownBlocks, hashes[i])
+
+		delete(dl.ancientChainTd, hashes[i])
+		delete(dl.ancientHeaders, hashes[i])
+		delete(dl.ancientReceipts, hashes[i])
+		delete(dl.ancientBlocks, hashes[i])
 	}
 }
 
@@ -411,13 +467,13 @@ func assertOwnForkedChain(t *testing.T, tester *downloadTester, common int, leng
 	if tester.downloader.mode == LightSync {
 		blocks, receipts = 1, 1
 	}
-	if hs := len(tester.ownHeaders); hs != headers {
+	if hs := len(tester.ownHeaders) + len(tester.ancientHeaders) - 1; hs != headers {
 		t.Fatalf("synchronised headers mismatch: have %v, want %v", hs, headers)
 	}
-	if bs := len(tester.ownBlocks); bs != blocks {
+	if bs := len(tester.ownBlocks) + len(tester.ancientBlocks) - 1; bs != blocks {
 		t.Fatalf("synchronised blocks mismatch: have %v, want %v", bs, blocks)
 	}
-	if rs := len(tester.ownReceipts); rs != receipts {
+	if rs := len(tester.ownReceipts) + len(tester.ancientReceipts) - 1; rs != receipts {
 		t.Fatalf("synchronised receipts mismatch: have %v, want %v", rs, receipts)
 	}
 }

ethdb/batch.go

@@ -23,7 +23,7 @@ const IdealBatchSize = 100 * 1024
 // Batch is a write-only database that commits changes to its host database
 // when Write is called. A batch cannot be used concurrently.
 type Batch interface {
-	Writer
+	KeyValueWriter
 
 	// ValueSize retrieves the amount of data queued up for writing.
 	ValueSize() int
@@ -35,7 +35,7 @@ type Batch interface {
 	Reset()
 
 	// Replay replays the batch contents.
-	Replay(w Writer) error
+	Replay(w KeyValueWriter) error
 }
 
 // Batcher wraps the NewBatch method of a backing data store.

ethdb/database.go

@@ -19,8 +19,8 @@ package ethdb
 
 import "io"
 
-// Reader wraps the Has and Get method of a backing data store.
-type Reader interface {
+// KeyValueReader wraps the Has and Get method of a backing data store.
+type KeyValueReader interface {
 	// Has retrieves if a key is present in the key-value data store.
 	Has(key []byte) (bool, error)
 
@@ -28,8 +28,8 @@ type Reader interface {
 	Get(key []byte) ([]byte, error)
 }
 
-// Writer wraps the Put method of a backing data store.
-type Writer interface {
+// KeyValueWriter wraps the Put method of a backing data store.
+type KeyValueWriter interface {
 	// Put inserts the given value into the key-value data store.
 	Put(key []byte, value []byte) error
 
@@ -58,8 +58,8 @@ type Compacter interface {
 // KeyValueStore contains all the methods required to allow handling different
 // key-value data stores backing the high level database.
 type KeyValueStore interface {
-	Reader
-	Writer
+	KeyValueReader
+	KeyValueWriter
 	Batcher
 	Iteratee
 	Stater
@@ -67,30 +67,58 @@ type KeyValueStore interface {
 	io.Closer
 }
 
-// Ancienter wraps the Ancient method for a backing immutable chain data store.
-type Ancienter interface {
+// AncientReader contains the methods required to read from immutable ancient data.
+type AncientReader interface {
+	// HasAncient returns an indicator whether the specified data exists in the
+	// ancient store.
+	HasAncient(kind string, number uint64) (bool, error)
+
 	// Ancient retrieves an ancient binary blob from the append-only immutable files.
 	Ancient(kind string, number uint64) ([]byte, error)
+
+	// Ancients returns the ancient store length
+	Ancients() (uint64, error)
+}
+
+// AncientWriter contains the methods required to write to immutable ancient data.
+type AncientWriter interface {
+	// AppendAncient injects all binary blobs belong to block at the end of the
+	// append-only immutable table files.
+	AppendAncient(number uint64, hash, header, body, receipt, td []byte) error
+
+	// TruncateAncients discards all but the first n ancient data from the ancient store.
+	TruncateAncients(n uint64) error
+
+	// Sync flushes all in-memory ancient store data to disk.
+	Sync() error
 }
 
-// AncientReader contains the methods required to access both key-value as well as
+// Reader contains the methods required to read data from both key-value as well as
 // immutable ancient data.
-type AncientReader interface {
-	Reader
-	Ancienter
+type Reader interface {
+	KeyValueReader
+	AncientReader
+}
+
+// Writer contains the methods required to write data to both key-value as well as
+// immutable ancient data.
+type Writer interface {
+	KeyValueWriter
+	AncientWriter
 }
 
 // AncientStore contains all the methods required to allow handling different
 // ancient data stores backing immutable chain data store.
 type AncientStore interface {
-	Ancienter
+	AncientReader
+	AncientWriter
 	io.Closer
 }
 
 // Database contains all the methods required by the high level database to not
 // only access the key-value data store but also the chain freezer.
 type Database interface {
-	AncientReader
+	Reader
 	Writer
 	Batcher
 	Iteratee

ethdb/leveldb/leveldb.go

@@ -425,13 +425,13 @@ func (b *batch) Reset() {
 }
 
 // Replay replays the batch contents.
-func (b *batch) Replay(w ethdb.Writer) error {
+func (b *batch) Replay(w ethdb.KeyValueWriter) error {
 	return b.b.Replay(&replayer{writer: w})
 }
 
 // replayer is a small wrapper to implement the correct replay methods.
 type replayer struct {
-	writer  ethdb.Writer
+	writer  ethdb.KeyValueWriter
 	failure error
 }
 

ethdb/memorydb/memorydb.go

@@ -270,7 +270,7 @@ func (b *batch) Reset() {
 }
 
 // Replay replays the batch contents.
-func (b *batch) Replay(w ethdb.Writer) error {
+func (b *batch) Replay(w ethdb.KeyValueWriter) error {
 	for _, keyvalue := range b.writes {
 		if keyvalue.delete {
 			if err := w.Delete(keyvalue.key); err != nil {

les/odr_requests.go

@@ -514,7 +514,7 @@ func (r *TxStatusRequest) Validate(db ethdb.Database, msg *Msg) error {
 // readTraceDB stores the keys of database reads. We use this to check that received node
 // sets contain only the trie nodes necessary to make proofs pass.
 type readTraceDB struct {
-	db    ethdb.Reader
+	db    ethdb.KeyValueReader
 	reads map[string]struct{}
 }
 

light/lightchain.go

@@ -165,12 +165,12 @@ func (lc *LightChain) loadLastState() error {
 
 // SetHead rewinds the local chain to a new head. Everything above the new
 // head will be deleted and the new one set.
-func (lc *LightChain) SetHead(head uint64) {
+func (lc *LightChain) SetHead(head uint64) error {
 	lc.chainmu.Lock()
 	defer lc.chainmu.Unlock()
 
-	lc.hc.SetHead(head, nil)
-	lc.loadLastState()
+	lc.hc.SetHead(head, nil, nil)
+	return lc.loadLastState()
 }
 
 // GasLimit returns the gas limit of the current HEAD block.

light/nodeset.go

@@ -115,7 +115,7 @@ func (db *NodeSet) NodeList() NodeList {
 }
 
 // Store writes the contents of the set to the given database
-func (db *NodeSet) Store(target ethdb.Writer) {
+func (db *NodeSet) Store(target ethdb.KeyValueWriter) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
@@ -124,11 +124,11 @@ func (db *NodeSet) Store(target ethdb.Writer) {
 	}
 }
 
-// NodeList stores an ordered list of trie nodes. It implements ethdb.Writer.
+// NodeList stores an ordered list of trie nodes. It implements ethdb.KeyValueWriter.
 type NodeList []rlp.RawValue
 
 // Store writes the contents of the list to the given database
-func (n NodeList) Store(db ethdb.Writer) {
+func (n NodeList) Store(db ethdb.KeyValueWriter) {
 	for _, node := range n {
 		db.Put(crypto.Keccak256(node), node)
 	}

light/trie.go

@@ -141,7 +141,7 @@ func (t *odrTrie) GetKey(sha []byte) []byte {
 	return nil
 }
 
-func (t *odrTrie) Prove(key []byte, fromLevel uint, proofDb ethdb.Writer) error {
+func (t *odrTrie) Prove(key []byte, fromLevel uint, proofDb ethdb.KeyValueWriter) error {
 	return errors.New("not implemented, needs client/server interface split")
 }
 

trie/database.go

@@ -321,7 +321,7 @@ func NewDatabaseWithCache(diskdb ethdb.KeyValueStore, cache int) *Database {
 }
 
 // DiskDB retrieves the persistent storage backing the trie database.
-func (db *Database) DiskDB() ethdb.Reader {
+func (db *Database) DiskDB() ethdb.KeyValueReader {
 	return db.diskdb
 }
 

trie/proof.go

@@ -33,7 +33,7 @@ import (
 // If the trie does not contain a value for key, the returned proof contains all
 // nodes of the longest existing prefix of the key (at least the root node), ending
 // with the node that proves the absence of the key.
-func (t *Trie) Prove(key []byte, fromLevel uint, proofDb ethdb.Writer) error {
+func (t *Trie) Prove(key []byte, fromLevel uint, proofDb ethdb.KeyValueWriter) error {
 	// Collect all nodes on the path to key.
 	key = keybytesToHex(key)
 	var nodes []node
@@ -96,16 +96,14 @@ func (t *Trie) Prove(key []byte, fromLevel uint, proofDb ethdb.Writer) error {
 // If the trie does not contain a value for key, the returned proof contains all
 // nodes of the longest existing prefix of the key (at least the root node), ending
 // with the node that proves the absence of the key.
-func (t *SecureTrie) Prove(key []byte, fromLevel uint, proofDb ethdb.Writer) error {
+func (t *SecureTrie) Prove(key []byte, fromLevel uint, proofDb ethdb.KeyValueWriter) error {
 	return t.trie.Prove(key, fromLevel, proofDb)
 }
 
 // VerifyProof checks merkle proofs. The given proof must contain the value for
 // key in a trie with the given root hash. VerifyProof returns an error if the
 // proof contains invalid trie nodes or the wrong value.
-//
-// Note, the method assumes that all key-values in proofDb satisfy key = hash(value).
-func VerifyProof(rootHash common.Hash, key []byte, proofDb ethdb.Reader) (value []byte, nodes int, err error) {
+func VerifyProof(rootHash common.Hash, key []byte, proofDb ethdb.KeyValueReader) (value []byte, nodes int, err error) {
 	key = keybytesToHex(key)
 	wantHash := rootHash
 	for i := 0; ; i++ {

trie/sync.go

@@ -72,7 +72,7 @@ func newSyncMemBatch() *syncMemBatch {
 // unknown trie hashes to retrieve, accepts node data associated with said hashes
 // and reconstructs the trie step by step until all is done.
 type Sync struct {
-	database ethdb.Reader             // Persistent database to check for existing entries
+	database ethdb.KeyValueReader     // Persistent database to check for existing entries
 	membatch *syncMemBatch            // Memory buffer to avoid frequent database writes
 	requests map[common.Hash]*request // Pending requests pertaining to a key hash
 	queue    *prque.Prque             // Priority queue with the pending requests
@@ -80,7 +80,7 @@ type Sync struct {
 }
 
 // NewSync creates a new trie data download scheduler.
-func NewSync(root common.Hash, database ethdb.Reader, callback LeafCallback, bloom *SyncBloom) *Sync {
+func NewSync(root common.Hash, database ethdb.KeyValueReader, callback LeafCallback, bloom *SyncBloom) *Sync {
 	ts := &Sync{
 		database: database,
 		membatch: newSyncMemBatch(),
@@ -224,7 +224,7 @@ func (s *Sync) Process(results []SyncResult) (bool, int, error) {
 
 // Commit flushes the data stored in the internal membatch out to persistent
 // storage, returning the number of items written and any occurred error.
-func (s *Sync) Commit(dbw ethdb.Writer) (int, error) {
+func (s *Sync) Commit(dbw ethdb.KeyValueWriter) (int, error) {
 	// Dump the membatch into a database dbw
 	for i, key := range s.membatch.order {
 		if err := dbw.Put(key[:], s.membatch.batch[key]); err != nil {