groot/rdict: proper handling of 'This' streamers

'This' streamers are used to extract the type argument of templates. e.g.: class MyVector: public std::vector<Foo> {...}; would be encoded as a TStreamerInfo named 'MyVector' and an element named "This" with a title "<Foo> Used to call ...". This technique seems to be used to properly extract 'Foo'. This seems to be also applied for other containers. (vector, deque, ...)
go-hep · Feb 16, 2022 · 34d6347 · 34d6347
1 parent 0a85f50
commit 34d6347
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Showing 3 changed files with 84 additions and 22 deletions.
diff --git a/groot/rdict/rwstreamer_test.go b/groot/rdict/rwstreamer_test.go
@@ -3252,6 +3252,24 @@ func TestRWStream(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "rmeta-stl-vector<set<int>>",
+			ptr: &struct {
+				F [][]int32
+			}{[][]int32{{1}, {2, 3}}},
+			si: &StreamerInfo{
+				named:  *rbase.NewNamed("T", "T"),
+				objarr: rcont.NewObjArray(),
+				elems: []rbytes.StreamerElement{
+					NewCxxStreamerSTL(Element{
+						Name:   *rbase.NewNamed("This", "Used to call the proper TStreamerInfo case"),
+						Type:   rmeta.STL,
+						MaxIdx: [5]int32{0, 0, 0, 0, 0},
+						EName:  "vector<set<int> >",
+					}.New(), rmeta.STLvector, rmeta.Object),
+				},
+			},
+		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			if tc.skip {

diff --git a/groot/rdict/type.go b/groot/rdict/type.go
@@ -194,10 +194,19 @@ func TypeFromSE(ctx rbytes.StreamerInfoContext, se rbytes.StreamerElement) (refl
 		case rmeta.STLvector, rmeta.STLlist, rmeta.STLdeque:
 			var (
 				ct       = se.ContainedType()
-				ename    = rmeta.CxxTemplateFrom(se.TypeName()).Args[0]
 				typevers = int16(-1)
-				elt, err = typeFromTypeName(ctx, ename, typevers, ct, se, 1)
+				ename    string
 			)
+			switch {
+			case hasThisHandling(se):
+				ename = se.Title()
+				ename = ename[:strings.Index(ename, "> Used to call the proper TStreamerInfo case")+1]
+				ename = strings.TrimSpace(ename)
+				ename = rmeta.CxxTemplateFrom("Type" + ename).Args[0]
+			default:
+				ename = rmeta.CxxTemplateFrom(se.TypeName()).Args[0]
+			}
+			elt, err := typeFromTypeName(ctx, ename, typevers, ct, se, 1)
 			if err != nil {
 				return nil, fmt.Errorf("rdict: could not create type for %q: %w", se.TypeName(), err)
 			}
@@ -208,8 +217,17 @@ func TypeFromSE(ctx rbytes.StreamerInfoContext, se rbytes.StreamerElement) (refl
 				ct       = se.ContainedType()
 				typename = se.TypeName()
 				typevers = int16(-1)
-				kname    = rmeta.CxxTemplateFrom(se.TypeName()).Args[0]
+				kname    string
 			)
+			switch {
+			case hasThisHandling(se):
+				kname = se.Title()
+				kname = kname[:strings.Index(kname, "> Used to call the proper TStreamerInfo case")+1]
+				kname = strings.TrimSpace(kname)
+				kname = rmeta.CxxTemplateFrom("Type" + kname).Args[0]
+			default:
+				kname = rmeta.CxxTemplateFrom(typename).Args[0]
+			}
 
 			key, err := typeFromTypeName(ctx, kname, typevers, ct, se, 1)
 			if err != nil {
@@ -224,10 +242,20 @@ func TypeFromSE(ctx rbytes.StreamerInfoContext, se rbytes.StreamerElement) (refl
 				ct       = se.ContainedType()
 				typename = se.TypeName()
 				typevers = int16(-1)
-				enames   = rmeta.CxxTemplateFrom(se.TypeName()).Args
-				kname    = enames[0]
-				vname    = enames[1]
+				enames   []string
 			)
+			switch {
+			case hasThisHandling(se):
+				ename := se.Title()
+				ename = ename[1:] // drop leading '<'
+				ename = ename[:strings.Index(ename, "> Used to call the proper TStreamerInfo case")]
+				ename = strings.TrimSpace(ename)
+				enames = rmeta.CxxTemplateFrom(ename).Args
+			default:
+				enames = rmeta.CxxTemplateFrom(typename).Args
+			}
+			kname := enames[0]
+			vname := enames[1]
 
 			key, err := typeFromTypeName(ctx, kname, typevers, ct, se, 1)
 			if err != nil {
@@ -560,3 +588,7 @@ func hasStdPrefix(typename string, ps ...string) bool {
 	}
 	return false
 }
+
+func hasThisHandling(se rbytes.StreamerElement) bool {
+	return se.Name() == "This" && strings.HasPrefix(se.Title(), "<")
+}
diff --git a/groot/rdict/type_test.go b/groot/rdict/type_test.go
@@ -204,11 +204,23 @@ func TestTypeFromSI(t *testing.T) {
 				ROOT_second float32 `groot:"second"`
 			})(nil)).Elem(),
 		},
+		{
+			name: "vector<int>",
+			si: rdict.NewCxxStreamerInfo("vector<int>", 1, 0, []rbytes.StreamerElement{
+				rdict.NewCxxStreamerSTL(rdict.Element{
+					Name:  *rbase.NewNamed("This", "<int> Used to call the proper TStreamerInfo case"),
+					Type:  rmeta.Streamer,
+					Size:  48,
+					EName: "vector<int>",
+				}.New(), rmeta.STLvector, rmeta.Object),
+			}),
+			want: reflect.TypeOf((*[]int32)(nil)).Elem(),
+		},
 		{
 			name: "list<int>",
 			si: rdict.NewCxxStreamerInfo("list<int>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<int> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "list<int>",
@@ -220,7 +232,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "deque<int>",
 			si: rdict.NewCxxStreamerInfo("deque<int>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<int> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "deque<int>",
@@ -232,7 +244,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "set<int>",
 			si: rdict.NewCxxStreamerInfo("set<int>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<int> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "set<int>",
@@ -244,7 +256,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "multiset<int>",
 			si: rdict.NewCxxStreamerInfo("multiset<int>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<int> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "set<int>",
@@ -256,7 +268,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "unordered_set<int>",
 			si: rdict.NewCxxStreamerInfo("unordered_set<int>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<int> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "unordered_set<int>",
@@ -268,7 +280,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "unordered_multiset<int>",
 			si: rdict.NewCxxStreamerInfo("unordered_multiset<int>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<int> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "unordered_multiset<int>",
@@ -280,7 +292,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "map<int,float>",
 			si: rdict.NewCxxStreamerInfo("map<int,float>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,float>> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "map<int,float>",
@@ -292,7 +304,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "multimap<int,float>",
 			si: rdict.NewCxxStreamerInfo("multimap<int,float>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,float>> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "multimap<int,float>",
@@ -304,7 +316,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "unordered_map<int,float>",
 			si: rdict.NewCxxStreamerInfo("unordered_map<int,float>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,float>> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "unordered_map<int,float>",
@@ -316,7 +328,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "unordered_multimap<int,float>",
 			si: rdict.NewCxxStreamerInfo("unordered_multimap<int,float>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,float>> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "unordered_multimap<int,float>",
@@ -328,7 +340,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "map<int,string>",
 			si: rdict.NewCxxStreamerInfo("map<int,string>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,string>> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "map<int,string>",
@@ -340,7 +352,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "map<int,TNamed>",
 			si: rdict.NewCxxStreamerInfo("map<int,TNamed>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,TNamed>> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "map<int,TNamed>",
@@ -352,7 +364,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "map<TNamed,int>",
 			si: rdict.NewCxxStreamerInfo("map<TNamed,int>", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<TNamed,int>> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "map<TNamed,int>",
@@ -364,7 +376,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "map<int,vector<TNamed> >",
 			si: rdict.NewCxxStreamerInfo("map<int,vector<TNamed> >", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,vector<TNamed> >> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "map<int,vector<TNamed> >",
@@ -376,7 +388,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "map<int,vector<string> >",
 			si: rdict.NewCxxStreamerInfo("map<int,vector<string> >", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,vector<string> >> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "map<int,vector<string> >",
@@ -388,7 +400,7 @@ func TestTypeFromSI(t *testing.T) {
 			name: "map<int,map<int,vector<string> > >",
 			si: rdict.NewCxxStreamerInfo("map<int,map<int,vector<string> > >", 1, 0, []rbytes.StreamerElement{
 				rdict.NewCxxStreamerSTL(rdict.Element{
-					Name:  *rbase.NewNamed("This", ""),
+					Name:  *rbase.NewNamed("This", "<pair<int,map<int,vector<string> > >> Used to call the proper TStreamerInfo case"),
 					Type:  rmeta.Streamer,
 					Size:  48,
 					EName: "map<int,map<int,vector<string> > >",