[wip] async traversal

cmd/stateSnapshot.go

@@ -37,20 +37,21 @@ var stateSnapshotCmd = &cobra.Command{
 }
 
 func stateSnapshot() {
-	snapConfig := snapshot.Config{}
+	serviceConfig := snapshot.ServiceConfig{}
-	snapConfig.Init()
+	serviceConfig.Init()
-	snapshotService, err := snapshot.NewSnapshotService(snapConfig)
+	snapshotService, err := snapshot.NewSnapshotService(serviceConfig)
 	if err != nil {
 		logWithCommand.Fatal(err)
 	}
 	height := viper.GetInt64("snapshot.blockHeight")
+	doAsync := viper.GetBool("snapshot.async")
 	if height < 0 {
-		if err := snapshotService.CreateLatestSnapshot(); err != nil {
+		if err := snapshotService.CreateLatestSnapshot(doAsync); err != nil {
 			logWithCommand.Fatal(err)
 		}
 	} else {
-		uHeight := uint64(height)
+		params := snapshot.SnapshotParams{Height: uint64(height), Async: doAsync}
-		if err := snapshotService.CreateSnapshot(uHeight); err != nil {
+		if err := snapshotService.CreateSnapshot(params); err != nil {
 			logWithCommand.Fatal(err)
 		}
 	}
@@ -63,8 +64,10 @@ func init() {
 	stateSnapshotCmd.PersistentFlags().String("leveldb-path", "", "path to primary datastore")
 	stateSnapshotCmd.PersistentFlags().String("ancient-path", "", "path to ancient datastore")
 	stateSnapshotCmd.PersistentFlags().String("block-height", "", "blockheight to extract state at")
+	stateSnapshotCmd.PersistentFlags().Bool("async", false, "use the async iterator")
 
 	viper.BindPFlag("leveldb.path", stateSnapshotCmd.PersistentFlags().Lookup("leveldb-path"))
 	viper.BindPFlag("leveldb.ancient", stateSnapshotCmd.PersistentFlags().Lookup("ancient-path"))
 	viper.BindPFlag("snapshot.blockHeight", stateSnapshotCmd.PersistentFlags().Lookup("block-height"))
+	viper.BindPFlag("snapshot.async", stateSnapshotCmd.PersistentFlags().Lookup("async"))
 }

pkg/snapshot/config.go

@@ -31,14 +31,14 @@ const (
 	LVL_DB_PATH       = "LVL_DB_PATH"
 )
 
-type Config struct {
+type ServiceConfig struct {
 	LevelDBPath   string
 	AncientDBPath string
 	Node          core.Node
 	DBConfig      config.Database
 }
 
-func (c *Config) Init() {
+func (c *ServiceConfig) Init() {
 	c.DBConfig.Init()
 	viper.BindEnv("leveldb.path", LVL_DB_PATH)
 	viper.BindEnv("ethereum.nodeID", ETH_NODE_ID)

pkg/snapshot/service.go

@@ -19,6 +19,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"sync"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
@@ -37,6 +38,7 @@ var (
 	emptyNode, _      = rlp.EncodeToBytes([]byte{})
 	emptyCodeHash     = crypto.Keccak256([]byte{})
 	emptyContractRoot = crypto.Keccak256Hash(emptyNode)
+	spawnDepth		  = 2
 )
 
 type Service struct {
@@ -45,7 +47,8 @@ type Service struct {
 	ipfsPublisher *Publisher
 }
 
-func NewSnapshotService(con Config) (*Service, error) {
+
+func NewSnapshotService(con ServiceConfig) (*Service, error) {
 	pgdb, err := postgres.NewDB(con.DBConfig, con.Node)
 	if err != nil {
 		return nil, err
@@ -61,93 +64,117 @@ func NewSnapshotService(con Config) (*Service, error) {
 	}, nil
 }
 
-func (s *Service) CreateLatestSnapshot() error {
+type SnapshotParams struct {
+	Height uint64
+	Async bool
+}
+
+type workerParams struct {
+	trieDB *trie.Database
+	headerID int64
+	waitGroup *sync.WaitGroup
+}
+
+func (s *Service) CreateSnapshot(par SnapshotParams) error {
 	// extract header from lvldb and publish to PG-IPFS
 	// hold onto the headerID so that we can link the state nodes to this header
+	logrus.Infof("Creating snapshot at height %d", par.Height)
+	hash := rawdb.ReadCanonicalHash(s.ethDB, par.Height)
+	header := rawdb.ReadHeader(s.ethDB, hash, par.Height)
+	if header == nil {
+		return fmt.Errorf("unable to read canonical header at height %d", par.Height)
+	}
+	headerID, err := s.ipfsPublisher.PublishHeader(header)
+	if err != nil {
+		return err
+	}
+	t, err := s.stateDB.OpenTrie(header.Root)
+	if err != nil {
+		return err
+	}
+	trieDB := s.stateDB.TrieDB()
+	params := workerParams{trieDB: trieDB, headerID: headerID}
+	if par.Async {
+		var wg sync.WaitGroup
+		params.waitGroup = &wg
+		return s.createSnapshotAsync(t.NodeIterator([]byte{}), 0, params)
+		wg.Wait()
+	} else {
+		return s.createSnapshot(t.NodeIterator([]byte{}), params)
+	}
+	return nil
+}
+
+// Create snapshot up to head (ignores height param)
+func (s *Service) CreateLatestSnapshot(doAsync bool) error {
 	logrus.Info("Creating snapshot at head")
 	hash := rawdb.ReadHeadHeaderHash(s.ethDB)
 	height := rawdb.ReadHeaderNumber(s.ethDB, hash)
 	if height == nil {
 		return fmt.Errorf("unable to read header height for header hash %s", hash.String())
 	}
-	header := rawdb.ReadHeader(s.ethDB, hash, *height)
+	return s.CreateSnapshot(SnapshotParams{Height: *height, Async: doAsync})
-	if header == nil {
-		return fmt.Errorf("unable to read canonical header at height %d", height)
-	}
-	logrus.Infof("head hash: %s head height: %d", hash.Hex(), *height)
-	headerID, err := s.ipfsPublisher.PublishHeader(header)
-	if err != nil {
-		return err
-	}
-	t, err := s.stateDB.OpenTrie(header.Root)
-	if err != nil {
-		return err
-	}
-	trieDB := s.stateDB.TrieDB()
-	return s.createSnapshot(t.NodeIterator([]byte{}), trieDB, headerID)
 }
 
-func (s *Service) CreateSnapshot(height uint64) error {
+// cache the elements
-	// extract header from lvldb and publish to PG-IPFS
+type nodeResult struct {
-	// hold onto the headerID so that we can link the state nodes to this header
+	node Node
-	logrus.Infof("Creating snapshot at height %d", height)
+	elements []interface{}
-	hash := rawdb.ReadCanonicalHash(s.ethDB, height)
-	header := rawdb.ReadHeader(s.ethDB, hash, height)
-	if header == nil {
-		return fmt.Errorf("unable to read canonical header at height %d", height)
-	}
-	headerID, err := s.ipfsPublisher.PublishHeader(header)
-	if err != nil {
-		return err
-	}
-	t, err := s.stateDB.OpenTrie(header.Root)
-	if err != nil {
-		return err
-	}
-	trieDB := s.stateDB.TrieDB()
-	return s.createSnapshot(t.NodeIterator([]byte{}), trieDB, headerID)
 }
 
-func (s *Service) createSnapshot(it trie.NodeIterator, trieDB *trie.Database, headerID int64) error {
+func resolveNode(it trie.NodeIterator, trieDB *trie.Database) (*nodeResult, error) {
-	for it.Next(true) {
-		if it.Leaf() { // "leaf" nodes are actually "value" nodes, whose parents are the actual leaves
-			continue
-		}
-		if bytes.Equal(nullHash.Bytes(), it.Hash().Bytes()) {
-			continue
-		}
 	nodePath := make([]byte, len(it.Path()))
 	copy(nodePath, it.Path())
 	node, err := trieDB.Node(it.Hash())
 	if err != nil {
-			return err
+		return nil, err
 	}
 	var nodeElements []interface{}
 	if err := rlp.DecodeBytes(node, &nodeElements); err != nil {
-			return err
+		return nil, err
 	}
 	ty, err := CheckKeyType(nodeElements)
 	if err != nil {
-			return err
+		return nil, err
 	}
-		stateNode := Node{
+	return &nodeResult{
+		node: Node{
 			NodeType: ty,
 			Path:     nodePath,
 			Value:    node,
+		},
+		elements: nodeElements,
+	}, nil
+}
+
+
+func (s *Service) processNode(it trie.NodeIterator, par workerParams) error {
+	fmt.Printf("    [!]: %v\n", it.Path())
+
+	if it.Leaf() { // "leaf" nodes are actually "value" nodes, whose parents are the actual leaves
+		return nil
 	}
-		switch ty {
+	if bytes.Equal(nullHash.Bytes(), it.Hash().Bytes()) {
+		return nil
+	}
+	res, err := resolveNode(it, par.trieDB)
+	if err != nil {
+		return err
+	}
+	switch res.node.NodeType {
 	case Leaf:
 		// if the node is a leaf, decode the account and publish the associated storage trie nodes if there are any
 		var account state.Account
-			if err := rlp.DecodeBytes(nodeElements[1].([]byte), &account); err != nil {
+		if err := rlp.DecodeBytes(res.elements[1].([]byte), &account); err != nil {
-				return fmt.Errorf("error decoding account for leaf node at path %x nerror: %v", nodePath, err)
+			return fmt.Errorf(
+				"error decoding account for leaf node at path %x nerror: %v", res.node.Path, err)
 		}
-			partialPath := trie.CompactToHex(nodeElements[0].([]byte))
+		partialPath := trie.CompactToHex(res.elements[0].([]byte))
-			valueNodePath := append(nodePath, partialPath...)
+		valueNodePath := append(res.node.Path, partialPath...)
 		encodedPath := trie.HexToCompact(valueNodePath)
 		leafKey := encodedPath[1:]
-			stateNode.Key = common.BytesToHash(leafKey)
+		res.node.Key = common.BytesToHash(leafKey)
-			stateID, err := s.ipfsPublisher.PublishStateNode(stateNode, headerID)
+		stateID, err := s.ipfsPublisher.PublishStateNode(res.node, par.headerID)
 		if err != nil {
 			return err
 		}
@@ -165,17 +192,75 @@ func (s *Service) createSnapshot(it trie.NodeIterator, trieDB *trie.Database, he
 			return fmt.Errorf("failed building storage snapshot for account %+v\r\nerror: %v", account, err)
 		}
 	case Extension, Branch:
-			stateNode.Key = common.BytesToHash([]byte{})
+		res.node.Key = common.BytesToHash([]byte{})
-			if _, err := s.ipfsPublisher.PublishStateNode(stateNode, headerID); err != nil {
+		if _, err := s.ipfsPublisher.PublishStateNode(res.node, par.headerID); err != nil {
 			return err
 		}
 	default:
 		return errors.New("unexpected node type")
 	}
+	return nil
+}
+
+func (s *Service) createSnapshot(it trie.NodeIterator, par workerParams) error {
+	if par.waitGroup != nil {
+		defer par.waitGroup.Done()
+	}
+	for it.Next(true) {
+		if err := s.processNode(it, par); err != nil {
+			return err
+		}
 	}
 	return it.Error()
 }
 
+// Iterate sequentially up to spawnDepth, then create workers to snapshot the subtrees
+func (s *Service) processNodeAsync(it trie.NodeIterator, depth int, par workerParams) error {
+	fmt.Printf("  [&, %v]: %v\n", depth, it.Path())
+
+	if it.Leaf() { // "leaf" nodes are actually "value" nodes, whose parents are the actual leaves
+		return nil
+	}
+	if bytes.Equal(nullHash.Bytes(), it.Hash().Bytes()) {
+		return nil
+	}
+	res, err := resolveNode(it, par.trieDB)
+	if err != nil {
+		return err
+	}
+	switch res.node.NodeType {
+	case Leaf:
+		depth = spawnDepth		// if it's a leaf, just spawn early
+	case Extension, Branch:
+		depth += 1
+	default:
+		return errors.New("unexpected node type")
+	}
+
+	// get a new iterator for the child
+	// XXX
+	t, err := s.stateDB.OpenTrie(it.Hash())
+	return s.createSnapshotAsync(t.NodeIterator(nil), depth, par)
+}
+
+func (s *Service) createSnapshotAsync(it trie.NodeIterator, depth int, par workerParams) error {
+	if depth >= spawnDepth {
+		print("  worker handoff\n")
+		par.waitGroup.Add(1)
+		go s.createSnapshot(it, par)
+		return nil
+	}
+
+	// shallow traversal so we can control the depth (?)
+	for it.Next(true) {
+		err := s.processNodeAsync(it, depth, par)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func (s *Service) storageSnapshot(sr common.Hash, stateID int64) error {
 	if bytes.Equal(sr.Bytes(), emptyContractRoot.Bytes()) {
 		return nil
@@ -193,38 +278,23 @@ func (s *Service) storageSnapshot(sr common.Hash, stateID int64) error {
 		if bytes.Equal(nullHash.Bytes(), it.Hash().Bytes()) {
 			continue
 		}
-		nodePath := make([]byte, len(it.Path()))
+		res, err := resolveNode(it, s.stateDB.TrieDB())
-		copy(nodePath, it.Path())
-		node, err := s.stateDB.TrieDB().Node(it.Hash())
 		if err != nil {
 			return err
 		}
-		var nodeElements []interface{}
+		switch res.node.NodeType {
-		if err := rlp.DecodeBytes(node, &nodeElements); err != nil {
-			return err
-		}
-		ty, err := CheckKeyType(nodeElements)
-		if err != nil {
-			return err
-		}
-		storageNode := Node{
-			NodeType: ty,
-			Path:     nodePath,
-			Value:    node,
-		}
-		switch ty {
 		case Leaf:
-			partialPath := trie.CompactToHex(nodeElements[0].([]byte))
+			partialPath := trie.CompactToHex(res.elements[0].([]byte))
-			valueNodePath := append(nodePath, partialPath...)
+			valueNodePath := append(res.node.Path, partialPath...)
 			encodedPath := trie.HexToCompact(valueNodePath)
 			leafKey := encodedPath[1:]
-			storageNode.Key = common.BytesToHash(leafKey)
+			res.node.Key = common.BytesToHash(leafKey)
 		case Extension, Branch:
-			storageNode.Key = common.BytesToHash([]byte{})
+			res.node.Key = common.BytesToHash([]byte{})
 		default:
 			return errors.New("unexpected node type")
 		}
-		if err := s.ipfsPublisher.PublishStorageNode(storageNode, stateID); err != nil {
+		if err := s.ipfsPublisher.PublishStorageNode(res.node, stateID); err != nil {
 			return err
 		}
 	}