Fix Issue 120

backend.go

@@ -1,9 +1,14 @@
 package onnx
 
 import (
+	"math"
+
 	"gonum.org/v1/gonum/graph"
 )
 
+// SelfEdge is the weight of a self edge in the graph
+const SelfEdge = math.MaxFloat64
+
 // Backend represent any backend able to receive a computation graph
 type Backend interface {
 	OperationCarrier

decoder.go

@@ -182,7 +182,8 @@ func (m *Model) decodeProto(model *pb.ModelProto) error {
 				m.dbByName[output] = no
 			}
 			// input should be ordered for non-commutatives operations
-			for i, input := range node.Input {
+			for i := 0; i < len(node.Input); i++ {
+				input := node.Input[i]
 				var ni graph.Node
 				var ok bool
 				if ni, ok = m.dbByName[input]; !ok {
@@ -194,6 +195,10 @@ func (m *Model) decodeProto(model *pb.ModelProto) error {
 					m.dbByName[input] = ni
 				}
 				e := dst.NewWeightedEdge(no, ni, float64(i))
+				if i < len(node.Input)-1 && contains(input, node.Input[i+1:]) {
+					node.Input = append(node.Input[:i], node.Input[i+1:]...)
+					e = dst.NewWeightedEdge(no, no, SelfEdge)
+				}
 				dst.SetWeightedEdge(e)
 			}
 			outputNodes[i] = no

dummy_backend_test.go

@@ -2,7 +2,6 @@ package onnx
 
 import (
 	"fmt"
-	"math"
 
 	"gonum.org/v1/gonum/graph"
 	"gonum.org/v1/gonum/graph/encoding"
@@ -91,7 +90,7 @@ func (n *nodeTest) ApplyTensor(t tensor.Tensor) error {
 // NewSimpleGraph ...
 func newTestBackend() *testBackend {
 	return &testBackend{
-		g: simple.NewWeightedDirectedGraph(math.MaxFloat64, -1),
+		g: simple.NewWeightedDirectedGraph(SelfEdge, -1),
 	}
 }
 
@@ -107,6 +106,7 @@ func (g *testBackend) AddNode(n graph.Node) {
 	g.g.AddNode(n)
 
 }
+
 func (g *testBackend) NewNode() graph.Node {
 	n := g.g.NewNode()
 	return &nodeTest{
@@ -151,3 +151,8 @@ func (g *testBackend) ApplyOperation(_ Operation, _ ...graph.Node) error {
 func (g *testBackend) WeightedEdge(uid, vid int64) graph.WeightedEdge {
 	return g.g.WeightedEdge(uid, vid)
 }
+
+// WeightedEdges returns all the weighted edges in the graph.
+func (g *testBackend) WeightedEdges() graph.WeightedEdges {
+	return g.g.WeightedEdges()
+}

internal/tools/dump/main.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+
+	"github.com/owulveryck/onnx-go/internal/pb-onnx"
+	"github.com/sanity-io/litter"
+)
+
+func main() {
+	onnxFile := os.Args[1]
+	b, err := ioutil.ReadFile(onnxFile)
+	if err != nil {
+		log.Fatal(err)
+	}
+	var m pb.ModelProto
+	err = m.XXX_Unmarshal(b)
+	if err != nil {
+		log.Fatal(err)
+	}
+	litter.Dump(m)
+
+}

self_node_test.go

@@ -0,0 +1,120 @@
+package onnx
+
+import (
+	"testing"
+
+	pb "github.com/owulveryck/onnx-go/internal/pb-onnx"
+	"gonum.org/v1/gonum/graph"
+)
+
+func TestDecodeProto_self(t *testing.T) {
+	input := &pb.ModelProto{
+		IrVersion: 5,
+		OpsetImport: []*pb.OperatorSetIdProto{
+			&pb.OperatorSetIdProto{
+				Domain:  "",
+				Version: 7,
+			},
+		},
+		ProducerName:    "tf2onnx",
+		ProducerVersion: "1.5.3",
+		Domain:          "",
+		ModelVersion:    0,
+		DocString:       "",
+		Graph: &pb.GraphProto{
+			Node: []*pb.NodeProto{
+				&pb.NodeProto{
+					Input: []string{
+						"x:0",
+						"x:0",
+					},
+					Output: []string{
+						"mul:0",
+					},
+					Name:      "mul",
+					OpType:    "Mul",
+					Domain:    "",
+					Attribute: nil,
+					DocString: "",
+				},
+			},
+			Name:        "tf2onnx",
+			Initializer: nil,
+			DocString:   "converted from ./model_nowind_test/export/",
+			Input: []*pb.ValueInfoProto{
+				&pb.ValueInfoProto{
+					Name: "x:0",
+					Type: &pb.TypeProto{
+						Value: &pb.TypeProto_TensorType{
+							TensorType: &pb.TypeProto_Tensor{
+								ElemType: 1,
+								Shape: &pb.TensorShapeProto{
+									Dim: []*pb.TensorShapeProto_Dimension{
+										&pb.TensorShapeProto_Dimension{
+											Value: &pb.TensorShapeProto_Dimension_DimValue{
+												DimValue: 1,
+											},
+											Denotation: "",
+										},
+									},
+								},
+							},
+						},
+						Denotation: "",
+					},
+					DocString: "",
+				},
+			},
+			Output: []*pb.ValueInfoProto{
+				&pb.ValueInfoProto{
+					Name: "mul:0",
+					Type: &pb.TypeProto{
+						Value: &pb.TypeProto_TensorType{
+							TensorType: &pb.TypeProto_Tensor{
+								ElemType: 1,
+								Shape: &pb.TensorShapeProto{
+									Dim: []*pb.TensorShapeProto_Dimension{
+										&pb.TensorShapeProto_Dimension{
+											Value: &pb.TensorShapeProto_Dimension_DimValue{
+												DimValue: 1,
+											},
+											Denotation: "",
+										},
+									},
+								},
+							},
+						},
+						Denotation: "",
+					},
+					DocString: "",
+				},
+			},
+			ValueInfo: nil,
+		},
+		MetadataProps: nil,
+	}
+	backend := newTestBackend()
+
+	m := NewModel(backend)
+	err := m.decodeProto(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+	edges := backend.WeightedEdges()
+	if edges.Len() != 2 {
+		t.Fatal("expected 2 weighted edges")
+	}
+	ee := make([]graph.WeightedEdge, 2)
+	for i := 0; edges.Next(); i++ {
+		ee[i] = edges.WeightedEdge()
+	}
+	for i := 0; i < len(ee); i++ {
+		if ee[i].From() == ee[i].To() && ee[i].Weight() == SelfEdge {
+			ee = ee[:len(ee)-1]
+		}
+		if ee[i].From() != ee[i].To() && ee[i].Weight() == 1 {
+			ee = ee[:len(ee)-1]
+		}
+	}
+
+}

utils_test.go

@@ -0,0 +1,20 @@
+package onnx
+
+import "testing"
+
+func TestContains(t *testing.T) {
+	table := []string{"a", "b", "c"}
+	ok := contains("a", table)
+	if !ok {
+		t.Fail()
+	}
+	ok = contains("z", table)
+	if ok {
+		t.Fail()
+	}
+	table = []string{"a", "a", "b", "c"}
+	ok = contains("a", table)
+	if !ok {
+		t.Fail()
+	}
+}

weighed_graph_test.go

@@ -1,15 +1,13 @@
 package onnx
 
 import (
-	"math"
-
 	"gonum.org/v1/gonum/graph"
 	"gonum.org/v1/gonum/graph/iterator"
 	"gonum.org/v1/gonum/graph/simple"
 )
 
 const (
-	self, absent = math.MaxFloat64, float64(-1)
+	absent = float64(-1)
 )
 
 type edge struct {
@@ -149,7 +147,7 @@ func (g *testExpectedGraph) To(id int64) graph.Nodes {
 // exists between x and y or if x and y have the same ID, false otherwise.
 func (g *testExpectedGraph) Weight(xid, yid int64) (w float64, ok bool) {
 	if xid == yid {
-		return self, true
+		return SelfEdge, true
 	}
 	if to, ok := g.from[xid]; ok {
 		if e, ok := to[yid]; ok {