Reuse origin metadata across configuration collections

internal/configuration/benchmark_test.go

@@ -126,6 +126,40 @@ func layeredDefinitions(count int) configurationShape {
 	}
 }
 
+func BenchmarkCollectionFileBackedConstruction(b *testing.B) {
+	for _, count := range []int{4, 16, 64} {
+		b.Run(fmt.Sprintf("collections_%d", count), func(b *testing.B) {
+			collections := make(map[string]any, count)
+			for index := range count {
+				collections[fmt.Sprintf("collection-%03d", index)] = map[string]any{
+					"prompts": map[string]any{
+						"example": map[string]any{
+							"messages": []any{map[string]any{"role": "user", "content_file": "body.md"}},
+							"output":   map[string]any{"format": "text", "validation_mode": "none"},
+						},
+					},
+				}
+			}
+			namespace := configkit.NewFilesystem("collection benchmark", fstest.MapFS{
+				"body.md": {Data: []byte("Hello")},
+			})
+			main := configkit.Input{
+				Source:     configkit.Mapping("collections", map[string]any{"collections": collections}),
+				Filesystem: &configkit.FilesystemContext{FS: &namespace, Root: ".", BaseDir: "."},
+			}
+			b.ReportAllocs()
+			for b.Loop() {
+				result, err := load(main, nil)
+				if err != nil {
+					b.Fatal(err)
+				}
+				constructionResult = result
+			}
+			b.ReportMetric(float64(count), "collections/op")
+		})
+	}
+}
+
 func BenchmarkConfigurationConstruction(b *testing.B) {
 	for _, scenario := range []struct {
 		name  string