Added message.Decode method

pkg/descriptor/message.go

@@ -1,6 +1,10 @@
 package descriptor
 
-import "time"
+import (
+	"time"
+
+	"go.einride.tech/can"
+)
 
 // Message describes a CAN message.
 type Message struct {
@@ -35,3 +39,39 @@ func (m *Message) MultiplexerSignal() (*Signal, bool) {
 	}
 	return nil, false
 }
+
+// Decode decodes a can Payload into a decoded signal array
+func (m *Message) Decode(p *can.Payload) []DecodedSignal {
+
+	var data can.Data
+	if m.Length <= 8 {
+		copy(data[:], p.Data)
+	}
+
+	numSignals := len(m.Signals)
+
+	signals := make([]DecodedSignal, numSignals)
+	for i, signal := range m.Signals {
+
+		var valueDesc string
+		var value float64
+		if m.Length > 8 {
+			valueDesc, _ = signal.UnmarshalValueDescriptionPayload(p)
+			value = signal.UnmarshalPhysicalPayload(p)
+		} else {
+			valueDesc, _ = signal.UnmarshalValueDescription(data)
+			value = signal.UnmarshalPhysical(data)
+		}
+
+		s := DecodedSignal{
+			Value:       value,
+			Description: valueDesc,
+			Signal:      signal,
+		}
+
+		signals[i] = s
+
+	}
+	return signals
+
+}

pkg/descriptor/signal.go

@@ -44,6 +44,15 @@ type Signal struct {
 	DefaultValue int
 }
 
+type DecodedSignal struct {
+	// Value is the physical value of a decoded signal
+	Value float64
+	// Description physical descritpion of a decoded signal
+	Description string
+	// Signal is a pointer to the dbc signal
+	Signal *Signal
+}
+
 // ValueDescription returns the value description for the provided value.
 func (s *Signal) ValueDescription(value int) (string, bool) {
 	for _, vd := range s.ValueDescriptions {

tests/decode_test.go

@@ -214,6 +214,20 @@ func TestDecodeEACVariables(t *testing.T) {
 			t.Errorf("signal[%s] value = %s ; expected: %s", name, valueDesc, expectedMap[name].description)
 		}
 	}
+
+	for _, signal := range message.Decode(&payload) {
+		value := signal.Value
+		valueDesc := signal.Description
+		name := signal.Signal.Name
+
+		if value != expectedMap[name].value {
+			t.Errorf("signal[%s] value = %f ; expected: %f", name, value, expectedMap[name].value)
+		}
+
+		if valueDesc != expectedMap[name].description {
+			t.Errorf("signal[%s] value = %s ; expected: %s", name, valueDesc, expectedMap[name].description)
+		}
+	}
 }
 
 func TestDecodeDisconnectState(t *testing.T) {
@@ -345,6 +359,33 @@ func TestDecodeSensorSonarsData(t *testing.T) {
 	}
 }
 
+func TestMessageDecodeSensorSonarsData(t *testing.T) {
+
+	data := can.Data{0x01, 0x01, 0x01, 0x02, 0x01, 0x00}
+	payload := can.Payload{Data: data[:]}
+
+	message, _ := db.Message(uint32(500))
+	fmt.Println(message.Length)
+
+	decodedSignals := message.Decode(&payload)
+	for _, signal := range decodedSignals {
+		value := signal.Value
+		valueDesc := signal.Description
+		name := signal.Signal.Name
+
+		valueFromData := signal.Signal.UnmarshalPhysical(data)
+		descFromData, _ := signal.Signal.UnmarshalValueDescription(data)
+
+		if value != valueFromData {
+			t.Errorf("signal[%s] value = %f ; expected: %f", name, value, valueFromData)
+		}
+
+		if valueDesc != descFromData {
+			t.Errorf("signal[%s] value = %s ; expected: %s", name, valueDesc, descFromData)
+		}
+	}
+}
+
 func BenchmarkDecodeData(b *testing.B) {
 
 	message, _ := db.Message(uint32(500))