Index inherited step membership

internal/engine/inheritance_origin.go

@@ -2,6 +2,7 @@ package engine
 
 import (
 	"slices"
+	"strconv"
 
 	"gitea.maximumdirect.net/eric/ConfigKit/internal/document"
 )
@@ -74,10 +75,44 @@ func copyInheritanceSubtree(target, incoming map[string]Origin, node *document.N
 	})
 }
 
+type inheritanceStepKey struct {
+	from      string
+	to        string
+	reference string
+	locations string
+}
+
+func inheritanceStepKeyForPaths(from, to, reference Path, locations []Location) inheritanceStepKey {
+	return inheritanceStepKey{
+		from: from.String(), to: to.String(), reference: reference.String(),
+		locations: inheritanceLocationsKey(locations),
+	}
+}
+
+func inheritanceLocationsKey(locations []Location) string {
+	encoded := strconv.AppendInt(nil, int64(len(locations)), 10)
+	encoded = append(encoded, ';')
+	for _, location := range locations {
+		encoded = strconv.AppendInt(encoded, int64(len(location.SourceID)), 10)
+		encoded = append(encoded, ':')
+		encoded = append(encoded, location.SourceID...)
+		encoded = append(encoded, ';')
+		encoded = strconv.AppendInt(encoded, int64(location.Line), 10)
+		encoded = append(encoded, ';')
+		encoded = strconv.AppendInt(encoded, int64(location.Column), 10)
+		encoded = append(encoded, ';')
+	}
+	return string(encoded)
+}
+
 // Materialize concrete steps only for an inspection record. The linked private
 // traces remain compact when one parent supplies many descendant values.
 func projectInheritanceSteps(origin Origin) []InheritanceStep {
 	steps := cloneInheritanceSteps(origin.Inheritance)
+	seen := make(map[inheritanceStepKey]struct{}, len(steps))
+	for _, step := range steps {
+		seen[inheritanceStepKeyForPaths(step.From, step.To, step.Reference, step.Locations)] = struct{}{}
+	}
 	for _, contributor := range origin.contributors {
 		var reverse []*inheritanceTrace
 		for link := contributor.trace; link != nil; link = link.previous {
@@ -91,17 +126,13 @@ func projectInheritanceSteps(origin Origin) []InheritanceStep {
 				continue
 			}
 			next := appendInheritancePath(transfer.to, relative)
-			step := InheritanceStep{
-				From: current.clone(), To: next.clone(), Reference: transfer.reference.clone(),
-				Locations: cloneLocations(transfer.locations),
-			}
-			if !slices.ContainsFunc(steps, func(existing InheritanceStep) bool {
-				return existing.From.String() == step.From.String() &&
-					existing.To.String() == step.To.String() &&
-					existing.Reference.String() == step.Reference.String() &&
-					slices.Equal(existing.Locations, step.Locations)
-			}) {
-				steps = append(steps, step)
+			key := inheritanceStepKeyForPaths(current, next, transfer.reference, transfer.locations)
+			if _, found := seen[key]; !found {
+				seen[key] = struct{}{}
+				steps = append(steps, InheritanceStep{
+					From: current.clone(), To: next.clone(), Reference: transfer.reference.clone(),
+					Locations: cloneLocations(transfer.locations),
+				})
 			}
 			current = next
 		}