trie: parallel commit (alternative version)

trie/committer.go

@@ -18,6 +18,7 @@ package trie
 
 import (
 	"fmt"
+	"sync"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/trie/trienode"
@@ -42,12 +43,12 @@ func newCommitter(nodeset *trienode.NodeSet, tracer *tracer, collectLeaf bool) *
 }
 
 // Commit collapses a node down into a hash node.
-func (c *committer) Commit(n node) hashNode {
-	return c.commit(nil, n).(hashNode)
+func (c *committer) Commit(n node, parallel bool) hashNode {
+	return c.commit(nil, n, parallel).(hashNode)
 }
 
 // commit collapses a node down into a hash node and returns it.
-func (c *committer) commit(path []byte, n node) node {
+func (c *committer) commit(path []byte, n node, parallel bool) node {
 	// if this path is clean, use available cached data
 	hash, dirty := n.cache()
 	if hash != nil && !dirty {
@@ -62,7 +63,7 @@ func (c *committer) commit(path []byte, n node) node {
 		// If the child is fullNode, recursively commit,
 		// otherwise it can only be hashNode or valueNode.
 		if _, ok := cn.Val.(*fullNode); ok {
-			collapsed.Val = c.commit(append(path, cn.Key...), cn.Val)
+			collapsed.Val = c.commit(append(path, cn.Key...), cn.Val, false)
 		}
 		// The key needs to be copied, since we're adding it to the
 		// modified nodeset.
@@ -73,7 +74,7 @@ func (c *committer) commit(path []byte, n node) node {
 		}
 		return collapsed
 	case *fullNode:
-		hashedKids := c.commitChildren(path, cn)
+		hashedKids := c.commitChildren(path, cn, parallel)
 		collapsed := cn.copy()
 		collapsed.Children = hashedKids
 
@@ -91,8 +92,12 @@ func (c *committer) commit(path []byte, n node) node {
 }
 
 // commitChildren commits the children of the given fullnode
-func (c *committer) commitChildren(path []byte, n *fullNode) [17]node {
-	var children [17]node
+func (c *committer) commitChildren(path []byte, n *fullNode, parallel bool) [17]node {
+	var (
+		wg       sync.WaitGroup
+		nodesMu  sync.Mutex
+		children [17]node
+	)
 	for i := 0; i < 16; i++ {
 		child := n.Children[i]
 		if child == nil {
@@ -108,7 +113,24 @@ func (c *committer) commitChildren(path []byte, n *fullNode) [17]node {
 		// Commit the child recursively and store the "hashed" value.
 		// Note the returned node can be some embedded nodes, so it's
 		// possible the type is not hashNode.
-		children[i] = c.commit(append(path, byte(i)), child)
+		if !parallel {
+			children[i] = c.commit(append(path, byte(i)), child, false)
+		} else {
+			wg.Add(1)
+			go func(index int) {
+				p := append(path, byte(index))
+				childSet := trienode.NewNodeSet(c.nodes.Owner)
+				childCommitter := newCommitter(childSet, c.tracer, c.collectLeaf)
+				children[index] = childCommitter.commit(p, child, false)
+				nodesMu.Lock()
+				c.nodes.MergeSet(childSet)
+				nodesMu.Unlock()
+				wg.Done()
+			}(i)
+		}
+	}
+	if parallel {
+		wg.Wait()
 	}
 	// For the 17th child, it's possible the type is valuenode.
 	if n.Children[16] != nil {

trie/trie.go

@@ -49,6 +49,9 @@ type Trie struct {
 	// actually unhashed nodes.
 	unhashed int
 
+	// uncommitted is the number of updates since last commit.
+	uncommitted int
+
 	// reader is the handler trie can retrieve nodes from.
 	reader *trieReader
 
@@ -64,12 +67,13 @@ func (t *Trie) newFlag() nodeFlag {
 // Copy returns a copy of Trie.
 func (t *Trie) Copy() *Trie {
 	return &Trie{
-		root:      t.root,
-		owner:     t.owner,
-		committed: t.committed,
-		unhashed:  t.unhashed,
-		reader:    t.reader,
-		tracer:    t.tracer.copy(),
+		root:        t.root,
+		owner:       t.owner,
+		committed:   t.committed,
+		reader:      t.reader,
+		tracer:      t.tracer.copy(),
+		uncommitted: t.uncommitted,
+		unhashed:    t.unhashed,
 	}
 }
 
@@ -309,6 +313,7 @@ func (t *Trie) Update(key, value []byte) error {
 
 func (t *Trie) update(key, value []byte) error {
 	t.unhashed++
+	t.uncommitted++
 	k := keybytesToHex(key)
 	if len(value) != 0 {
 		_, n, err := t.insert(t.root, nil, k, valueNode(value))
@@ -422,6 +427,7 @@ func (t *Trie) Delete(key []byte) error {
 	if t.committed {
 		return ErrCommitted
 	}
+	t.uncommitted++
 	t.unhashed++
 	k := keybytesToHex(key)
 	_, n, err := t.delete(t.root, nil, k)
@@ -642,7 +648,9 @@ func (t *Trie) Commit(collectLeaf bool) (common.Hash, *trienode.NodeSet) {
 	for _, path := range t.tracer.deletedNodes() {
 		nodes.AddNode([]byte(path), trienode.NewDeleted())
 	}
-	t.root = newCommitter(nodes, t.tracer, collectLeaf).Commit(t.root)
+	// If the number of changes is below 100, we let one thread handle it
+	t.root = newCommitter(nodes, t.tracer, collectLeaf).Commit(t.root, t.uncommitted > 100)
+	t.uncommitted = 0
 	return rootHash, nodes
 }
 
@@ -678,6 +686,7 @@ func (t *Trie) Reset() {
 	t.root = nil
 	t.owner = common.Hash{}
 	t.unhashed = 0
+	t.uncommitted = 0
 	t.tracer.reset()
 	t.committed = false
 }

trie/trie_test.go

@@ -26,6 +26,7 @@ import (
 	"math/rand"
 	"reflect"
 	"sort"
+	"strings"
 	"testing"
 	"testing/quick"
 
@@ -35,6 +36,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/internal/testrand"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie/trienode"
 	"github.com/holiman/uint256"
@@ -1206,3 +1208,105 @@ func FuzzTrie(f *testing.F) {
 		}
 	})
 }
+
+func BenchmarkCommit(b *testing.B) {
+	benchmarkCommit(b, 100)
+	benchmarkCommit(b, 500)
+	benchmarkCommit(b, 2000)
+	benchmarkCommit(b, 5000)
+}
+
+func benchmarkCommit(b *testing.B, n int) {
+	b.Run(fmt.Sprintf("commit-%vnodes-sequential", n), func(b *testing.B) {
+		testCommit(b, n, false)
+	})
+	b.Run(fmt.Sprintf("commit-%vnodes-parallel", n), func(b *testing.B) {
+		testCommit(b, n, true)
+	})
+}
+
+func testCommit(b *testing.B, n int, parallel bool) {
+	tries := make([]*Trie, b.N)
+	for i := 0; i < b.N; i++ {
+		tries[i] = NewEmpty(nil)
+		for j := 0; j < n; j++ {
+			key := testrand.Bytes(32)
+			val := testrand.Bytes(32)
+			tries[i].Update(key, val)
+		}
+		tries[i].Hash()
+		if !parallel {
+			tries[i].uncommitted = 0
+		}
+	}
+	b.ResetTimer()
+	b.ReportAllocs()
+	for i := 0; i < len(tries); i++ {
+		tries[i].Commit(true)
+	}
+}
+
+func TestCommitCorrect(t *testing.T) {
+	var paraTrie = NewEmpty(nil)
+	var refTrie = NewEmpty(nil)
+
+	for j := 0; j < 5000; j++ {
+		key := testrand.Bytes(32)
+		val := testrand.Bytes(32)
+		paraTrie.Update(key, val)
+		refTrie.Update(common.CopyBytes(key), common.CopyBytes(val))
+	}
+	paraTrie.Hash()
+	refTrie.Hash()
+	refTrie.uncommitted = 0
+
+	haveRoot, haveNodes := paraTrie.Commit(true)
+	wantRoot, wantNodes := refTrie.Commit(true)
+
+	if haveRoot != wantRoot {
+		t.Fatalf("have %x want %x", haveRoot, wantRoot)
+	}
+	have := printSet(haveNodes)
+	want := printSet(wantNodes)
+	if have != want {
+		i := 0
+		for i = 0; i < len(have); i++ {
+			if have[i] != want[i] {
+				break
+			}
+		}
+		if i > 100 {
+			i -= 100
+		}
+		t.Fatalf("have != want\nhave %q\nwant %q", have[i:], want[i:])
+	}
+}
+func printSet(set *trienode.NodeSet) string {
+	var out = new(strings.Builder)
+	fmt.Fprintf(out, "nodeset owner: %v\n", set.Owner)
+	var paths []string
+	for k := range set.Nodes {
+		paths = append(paths, k)
+	}
+	sort.Strings(paths)
+
+	for _, path := range paths {
+		n := set.Nodes[path]
+		// Deletion
+		if n.IsDeleted() {
+			fmt.Fprintf(out, "  [-]: %x\n", path)
+			continue
+		}
+		// Insertion or update
+		fmt.Fprintf(out, "  [+/*]: %x -> %v \n", path, n.Hash)
+	}
+	sort.Slice(set.Leaves, func(i, j int) bool {
+		a := set.Leaves[i]
+		b := set.Leaves[j]
+		return bytes.Compare(a.Parent[:], b.Parent[:]) < 0
+	})
+	for _, n := range set.Leaves {
+		fmt.Fprintf(out, "[leaf]: %v\n", n)
+	}
+	return out.String()
+}

trie/trienode/node.go

@@ -18,6 +18,7 @@ package trienode
 
 import (
 	"fmt"
+	"maps"
 	"sort"
 	"strings"
 
@@ -99,6 +100,23 @@ func (set *NodeSet) AddNode(path []byte, n *Node) {
 	set.Nodes[string(path)] = n
 }
 
+// MergeSet merges this 'set' with 'other'. It assumes that the sets are disjoint,
+// and thus does not deduplicate data (count deletes, dedup leaves etc).
+func (set *NodeSet) MergeSet(other *NodeSet) error {
+	if set.Owner != other.Owner {
+		return fmt.Errorf("nodesets belong to different owner are not mergeable %x-%x", set.Owner, other.Owner)
+	}
+	maps.Copy(set.Nodes, other.Nodes)
+
+	set.deletes += other.deletes
+	set.updates += other.updates
+
+	// Since we assume the sets are disjoint, we can safely append leaves
+	// like this without deduplication.
+	set.Leaves = append(set.Leaves, other.Leaves...)
+	return nil
+}
+
 // Merge adds a set of nodes into the set.
 func (set *NodeSet) Merge(owner common.Hash, nodes map[string]*Node) error {
 	if set.Owner != owner {