Improve tracing of merkledb trie updates (#2897)

Author: StephenButtolph

x/merkledb/db.go

@@ -216,9 +216,9 @@ type merkleDB struct {
 	// Valid children of this trie.
 	childViews []*view
 
-	// calculateNodeIDsSema controls the number of goroutines inside
-	// [calculateNodeIDsHelper] at any given time.
-	calculateNodeIDsSema *semaphore.Weighted
+	// hashNodesSema controls the number of goroutines that are created inside
+	// [hashChangedNode] at any given time.
+	hashNodesSema *semaphore.Weighted
 
 	tokenSize int
 }
@@ -270,12 +270,12 @@ func newDatabase(
 			bufferPool,
 			metrics,
 			int(config.ValueNodeCacheSize)),
-		history:              newTrieHistory(int(config.HistoryLength)),
-		debugTracer:          getTracerIfEnabled(config.TraceLevel, DebugTrace, config.Tracer),
-		infoTracer:           getTracerIfEnabled(config.TraceLevel, InfoTrace, config.Tracer),
-		childViews:           make([]*view, 0, defaultPreallocationSize),
-		calculateNodeIDsSema: semaphore.NewWeighted(int64(rootGenConcurrency)),
-		tokenSize:            BranchFactorToTokenSize[config.BranchFactor],
+		history:       newTrieHistory(int(config.HistoryLength)),
+		debugTracer:   getTracerIfEnabled(config.TraceLevel, DebugTrace, config.Tracer),
+		infoTracer:    getTracerIfEnabled(config.TraceLevel, InfoTrace, config.Tracer),
+		childViews:    make([]*view, 0, defaultPreallocationSize),
+		hashNodesSema: semaphore.NewWeighted(int64(rootGenConcurrency)),
+		tokenSize:     BranchFactorToTokenSize[config.BranchFactor],
 	}
 
 	if err := trieDB.initializeRoot(); err != nil {

x/merkledb/history.go

@@ -57,7 +57,7 @@ type changeSummary struct {
 	// The ID of the trie after these changes.
 	rootID ids.ID
 	// The root before/after this change.
-	// Set in [calculateNodeIDs].
+	// Set in [applyValueChanges].
 	rootChange change[maybe.Maybe[*node]]
 	nodes      map[Key]*change[*node]
 	values     map[Key]*change[maybe.Maybe[[]byte]]

x/merkledb/trie_test.go

@@ -21,7 +21,7 @@ import (
 func getNodeValue(t Trie, key string) ([]byte, error) {
 	path := ToKey([]byte(key))
 	if asView, ok := t.(*view); ok {
-		if err := asView.calculateNodeIDs(context.Background()); err != nil {
+		if err := asView.applyValueChanges(context.Background()); err != nil {
 			return nil, err
 		}
 	}
@@ -131,7 +131,7 @@ func TestVisitPathToKey(t *testing.T) {
 	require.NoError(err)
 	require.IsType(&view{}, trieIntf)
 	trie = trieIntf.(*view)
-	require.NoError(trie.calculateNodeIDs(context.Background()))
+	require.NoError(trie.applyValueChanges(context.Background()))
 
 	nodePath = make([]*node, 0, 1)
 	require.NoError(visitPathToKey(trie, ToKey(key1), func(n *node) error {
@@ -156,7 +156,7 @@ func TestVisitPathToKey(t *testing.T) {
 	require.NoError(err)
 	require.IsType(&view{}, trieIntf)
 	trie = trieIntf.(*view)
-	require.NoError(trie.calculateNodeIDs(context.Background()))
+	require.NoError(trie.applyValueChanges(context.Background()))
 
 	nodePath = make([]*node, 0, 2)
 	require.NoError(visitPathToKey(trie, ToKey(key2), func(n *node) error {
@@ -185,7 +185,7 @@ func TestVisitPathToKey(t *testing.T) {
 	require.NoError(err)
 	require.IsType(&view{}, trieIntf)
 	trie = trieIntf.(*view)
-	require.NoError(trie.calculateNodeIDs(context.Background()))
+	require.NoError(trie.applyValueChanges(context.Background()))
 
 	// Trie is:
 	//    []
@@ -775,7 +775,7 @@ func Test_Trie_ChainDeletion(t *testing.T) {
 	)
 	require.NoError(err)
 
-	require.NoError(newTrie.(*view).calculateNodeIDs(context.Background()))
+	require.NoError(newTrie.(*view).applyValueChanges(context.Background()))
 	maybeRoot := newTrie.getRoot()
 	require.NoError(err)
 	require.True(maybeRoot.HasValue())
@@ -794,7 +794,7 @@ func Test_Trie_ChainDeletion(t *testing.T) {
 		},
 	)
 	require.NoError(err)
-	require.NoError(newTrie.(*view).calculateNodeIDs(context.Background()))
+	require.NoError(newTrie.(*view).applyValueChanges(context.Background()))
 
 	// trie should be empty
 	root := newTrie.getRoot()
@@ -861,7 +861,7 @@ func Test_Trie_NodeCollapse(t *testing.T) {
 	)
 	require.NoError(err)
 
-	require.NoError(trie.(*view).calculateNodeIDs(context.Background()))
+	require.NoError(trie.(*view).applyValueChanges(context.Background()))
 
 	for _, kv := range kvs {
 		node, err := trie.getEditableNode(ToKey(kv.Key), true)
@@ -888,7 +888,7 @@ func Test_Trie_NodeCollapse(t *testing.T) {
 	)
 	require.NoError(err)
 
-	require.NoError(trie.(*view).calculateNodeIDs(context.Background()))
+	require.NoError(trie.(*view).applyValueChanges(context.Background()))
 
 	for _, kv := range deletedKVs {
 		_, err := trie.getEditableNode(ToKey(kv.Key), true)