SSZ-QL: use FastSSZ-generated HashTreeRoot through SSZObject in sszInfo (#15805)

* stored CL object to enable the usage Fastssz's HashTreeRoot(). added basic test

* refactorization - using interfaces instead of storing original object

* added tests covering ssz custom types

* renamed hash_tree_root to ssz_interface as it contains MarshalSSZ and UnmarshalSSZ functions

* run gazelle

* renamed test and improved comments

* refactored test and extend to marshalSSZ and UnmarshalSSZ

* added changelog

* updated comment

* Changed SSZIface name to SSZObject. Removed MarshalSSZ and UnmarshalSSZ function signatures from interface as they are not used still. Refactored tests.

* renamed file ssz_interface.go to ssz_object.go. merge test from ssz_interface_test.go into query_test.go.
reordered source SSZObject field from sszInfo struct

* sticked SSZObject interface to HashTreeRoot() function, the only one needed so far

* run gazelle :)

---------

Co-authored-by: Radosław Kapka <rkapka@wp.pl>

changelog/fernantho_ssz-ql-use-fastssz-generated-functions.md

@@ -0,0 +1,3 @@
+### Added
+
+- Delegate sszInfo HashTreeRoot to FastSSZ-generated implementations via SSZObject, enabling roots calculation for generated types while avoiding duplicate logic.

encoding/ssz/query/BUILD.bazel

@@ -11,6 +11,7 @@ go_library(
         "path.go",
         "query.go",
         "ssz_info.go",
+        "ssz_object.go",
         "ssz_type.go",
         "tag_parser.go",
         "vector.go",

encoding/ssz/query/analyzer.go

@@ -10,7 +10,7 @@ import (
 const offsetBytes = 4
 
 // AnalyzeObject analyzes given object and returns its SSZ information.
-func AnalyzeObject(obj any) (*sszInfo, error) {
+func AnalyzeObject(obj SSZObject) (*sszInfo, error) {
 	value := dereferencePointer(obj)
 
 	info, err := analyzeType(value.Type(), nil)
@@ -18,6 +18,9 @@ func AnalyzeObject(obj any) (*sszInfo, error) {
 		return nil, fmt.Errorf("could not analyze type %s: %w", value.Type().Name(), err)
 	}
 
+	// Store the original object interface
+	info.source = obj
+
 	// Populate variable-length information using the actual value.
 	err = PopulateVariableLengthInfo(info, value.Interface())
 	if err != nil {

encoding/ssz/query/query_test.go

@@ -302,7 +302,7 @@ func getFixedTestContainerSpec() testutil.TestSpec {
 
 	return testutil.TestSpec{
 		Name:     "FixedTestContainer",
-		Type:     sszquerypb.FixedTestContainer{},
+		Type:     &sszquerypb.FixedTestContainer{},
 		Instance: testContainer,
 		PathTests: []testutil.PathTest{
 			// Basic types
@@ -364,6 +364,62 @@ func getFixedTestContainerSpec() testutil.TestSpec {
 	}
 }
 
+func TestSSZObject_batch(t *testing.T) {
+	tests := []struct {
+		name string
+		obj  any
+	}{
+		{
+			name: "FixedNestedContainer",
+			obj: &sszquerypb.FixedNestedContainer{
+				Value1: 42,
+				Value2: []byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08},
+			},
+		},
+		{
+			name: "FixedTestContainer",
+			obj:  createFixedTestContainer(),
+		},
+		{
+			name: "VariableNestedContainer",
+			obj: &sszquerypb.VariableNestedContainer{
+				Value1:          84,
+				FieldListUint64: []uint64{1, 2, 3, 4, 5},
+				NestedListField: [][]byte{
+					{0x0a, 0x0b, 0x0c},
+					{0x1a, 0x1b, 0x1c, 0x1d},
+				},
+			},
+		},
+		{
+			name: "VariableTestContainer",
+			obj:  createVariableTestContainer(),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Analyze the object to get its sszInfo
+			object, ok := tt.obj.(query.SSZObject)
+			require.Equal(t, true, ok, "Expected object to implement SSZObject")
+			info, err := query.AnalyzeObject(object)
+			require.NoError(t, err)
+			require.NotNil(t, info, "Expected non-nil SSZ info")
+
+			// Ensure the original object implements SSZObject
+			originalFunctions, ok := tt.obj.(query.SSZObject)
+			require.Equal(t, ok, true, "Original object does not implement SSZObject")
+
+			// Call HashTreeRoot on the sszInfo and compare results
+			hashTreeRoot, err := info.HashTreeRoot()
+			require.NoError(t, err, "HashTreeRoot should not return an error")
+			expectedHashTreeRoot, err := originalFunctions.HashTreeRoot()
+			require.NoError(t, err, "HashTreeRoot on original object should not return an error")
+			require.Equal(t, expectedHashTreeRoot, hashTreeRoot, "HashTreeRoot from sszInfo should match original object's HashTreeRoot")
+		})
+	}
+}
+
 func createVariableTestContainer() *sszquerypb.VariableTestContainer {
 	leadingField := make([]byte, 32)
 	for i := range leadingField {
@@ -439,7 +495,7 @@ func getVariableTestContainerSpec() testutil.TestSpec {
 
 	return testutil.TestSpec{
 		Name:     "VariableTestContainer",
-		Type:     sszquerypb.VariableTestContainer{},
+		Type:     &sszquerypb.VariableTestContainer{},
 		Instance: testContainer,
 		PathTests: []testutil.PathTest{
 			// Fixed leading field

encoding/ssz/query/ssz_info.go

@@ -13,6 +13,8 @@ type sszInfo struct {
 	sszType SSZType
 	// Type in Go. Need this for unmarshaling.
 	typ reflect.Type
+	// Original object being analyzed
+	source SSZObject
 
 	// isVariable is true if the struct contains any variable-size fields.
 	isVariable bool

encoding/ssz/query/ssz_object.go

@@ -0,0 +1,22 @@
+package query
+
+import "errors"
+
+type SSZObject interface {
+	HashTreeRoot() ([32]byte, error)
+}
+
+// HashTreeRoot calls the HashTreeRoot method on the stored interface if it implements SSZObject.
+// Returns the 32-byte hash tree root or an error if the interface doesn't support hashing.
+func (info *sszInfo) HashTreeRoot() ([32]byte, error) {
+	if info == nil {
+		return [32]byte{}, errors.New("sszInfo is nil")
+	}
+
+	if info.source == nil {
+		return [32]byte{}, errors.New("sszInfo.source is nil")
+	}
+
+	// Check if the value implements the Hashable interface
+	return info.source.HashTreeRoot()
+}

encoding/ssz/query/testutil/runner.go

@@ -10,7 +10,10 @@ import (
 
 func RunStructTest(t *testing.T, spec TestSpec) {
 	t.Run(spec.Name, func(t *testing.T) {
-		info, err := query.AnalyzeObject(spec.Type)
+		object, ok := spec.Type.(query.SSZObject)
+		require.Equal(t, true, ok, "spec.Type must implement SSZObject interface")
+		require.NotNil(t, object, "spec.Type must not be nil")
+		info, err := query.AnalyzeObject(object)
 		require.NoError(t, err)
 
 		testInstance := spec.Instance

encoding/ssz/query/testutil/type.go

@@ -1,5 +1,7 @@
 package testutil
 
+import "github.com/OffchainLabs/prysm/v6/encoding/ssz/query"
+
 type PathTest struct {
 	Path     string
 	Expected any
@@ -7,7 +9,7 @@ type PathTest struct {
 
 type TestSpec struct {
 	Name      string
-	Type      any
-	Instance  any
+	Type      query.SSZObject
+	Instance  query.SSZObject
 	PathTests []PathTest
 }