new: new can module for CAN-bus

modules/can/dbc.go

@@ -0,0 +1,227 @@
+package can
+
+import (
+	"fmt"
+	"sort"
+	"time"
+
+	"go.einride.tech/can/pkg/dbc"
+	"go.einride.tech/can/pkg/descriptor"
+)
+
+type CompileResult struct {
+	Database *descriptor.Database
+	Warnings []error
+}
+
+func dbcCompile(sourceFile string, data []byte) (result *CompileResult, err error) {
+	p := dbc.NewParser(sourceFile, data)
+	if err := p.Parse(); err != nil {
+		return nil, fmt.Errorf("failed to parse DBC source file: %w", err)
+	}
+	defs := p.Defs()
+	c := &compiler{
+		db:   &descriptor.Database{SourceFile: sourceFile},
+		defs: defs,
+	}
+	c.collectDescriptors()
+	c.addMetadata()
+	c.sortDescriptors()
+	return &CompileResult{Database: c.db, Warnings: c.warnings}, nil
+}
+
+type compileError struct {
+	def    dbc.Def
+	reason string
+}
+
+func (e *compileError) Error() string {
+	return fmt.Sprintf("failed to compile: %v (%v)", e.reason, e.def)
+}
+
+type compiler struct {
+	db       *descriptor.Database
+	defs     []dbc.Def
+	warnings []error
+}
+
+func (c *compiler) addWarning(warning error) {
+	c.warnings = append(c.warnings, warning)
+}
+
+func (c *compiler) collectDescriptors() {
+	for _, def := range c.defs {
+		switch def := def.(type) {
+		case *dbc.VersionDef:
+			c.db.Version = def.Version
+		case *dbc.MessageDef:
+			if def.MessageID == dbc.IndependentSignalsMessageID {
+				continue // don't compile
+			}
+			message := &descriptor.Message{
+				Name:       string(def.Name),
+				ID:         def.MessageID.ToCAN(),
+				IsExtended: def.MessageID.IsExtended(),
+				Length:     uint8(def.Size),
+				SenderNode: string(def.Transmitter),
+			}
+			for _, signalDef := range def.Signals {
+				signal := &descriptor.Signal{
+					Name:             string(signalDef.Name),
+					IsBigEndian:      signalDef.IsBigEndian,
+					IsSigned:         signalDef.IsSigned,
+					IsMultiplexer:    signalDef.IsMultiplexerSwitch,
+					IsMultiplexed:    signalDef.IsMultiplexed,
+					MultiplexerValue: uint(signalDef.MultiplexerSwitch),
+					Start:            uint8(signalDef.StartBit),
+					Length:           uint8(signalDef.Size),
+					Scale:            signalDef.Factor,
+					Offset:           signalDef.Offset,
+					Min:              signalDef.Minimum,
+					Max:              signalDef.Maximum,
+					Unit:             signalDef.Unit,
+				}
+				for _, receiver := range signalDef.Receivers {
+					signal.ReceiverNodes = append(signal.ReceiverNodes, string(receiver))
+				}
+				message.Signals = append(message.Signals, signal)
+			}
+			c.db.Messages = append(c.db.Messages, message)
+		case *dbc.NodesDef:
+			for _, node := range def.NodeNames {
+				c.db.Nodes = append(c.db.Nodes, &descriptor.Node{Name: string(node)})
+			}
+		}
+	}
+}
+
+func (c *compiler) addMetadata() {
+	for _, def := range c.defs {
+		switch def := def.(type) {
+		case *dbc.SignalValueTypeDef:
+			signal, ok := c.db.Signal(def.MessageID.ToCAN(), string(def.SignalName))
+			if !ok {
+				c.addWarning(&compileError{def: def, reason: "no declared signal"})
+				continue
+			}
+			switch def.SignalValueType {
+			case dbc.SignalValueTypeInt:
+				signal.IsFloat = false
+			case dbc.SignalValueTypeFloat32:
+				if signal.Length == 32 {
+					signal.IsFloat = true
+				} else {
+					reason := fmt.Sprintf("incorrect float signal length: %d", signal.Length)
+					c.addWarning(&compileError{def: def, reason: reason})
+				}
+			default:
+				reason := fmt.Sprintf("unsupported signal value type: %v", def.SignalValueType)
+				c.addWarning(&compileError{def: def, reason: reason})
+			}
+		case *dbc.CommentDef:
+			switch def.ObjectType {
+			case dbc.ObjectTypeMessage:
+				if def.MessageID == dbc.IndependentSignalsMessageID {
+					continue // don't compile
+				}
+				message, ok := c.db.Message(def.MessageID.ToCAN())
+				if !ok {
+					c.addWarning(&compileError{def: def, reason: "no declared message"})
+					continue
+				}
+				message.Description = def.Comment
+			case dbc.ObjectTypeSignal:
+				if def.MessageID == dbc.IndependentSignalsMessageID {
+					continue // don't compile
+				}
+				signal, ok := c.db.Signal(def.MessageID.ToCAN(), string(def.SignalName))
+				if !ok {
+					c.addWarning(&compileError{def: def, reason: "no declared signal"})
+					continue
+				}
+				signal.Description = def.Comment
+			case dbc.ObjectTypeNetworkNode:
+				node, ok := c.db.Node(string(def.NodeName))
+				if !ok {
+					c.addWarning(&compileError{def: def, reason: "no declared node"})
+					continue
+				}
+				node.Description = def.Comment
+			}
+		case *dbc.ValueDescriptionsDef:
+			if def.MessageID == dbc.IndependentSignalsMessageID {
+				continue // don't compile
+			}
+			if def.ObjectType != dbc.ObjectTypeSignal {
+				continue // don't compile
+			}
+			signal, ok := c.db.Signal(def.MessageID.ToCAN(), string(def.SignalName))
+			if !ok {
+				c.addWarning(&compileError{def: def, reason: "no declared signal"})
+				continue
+			}
+			for _, valueDescription := range def.ValueDescriptions {
+				signal.ValueDescriptions = append(signal.ValueDescriptions, &descriptor.ValueDescription{
+					Description: valueDescription.Description,
+					Value:       int64(valueDescription.Value),
+				})
+			}
+		case *dbc.AttributeValueForObjectDef:
+			switch def.ObjectType {
+			case dbc.ObjectTypeMessage:
+				msg, ok := c.db.Message(def.MessageID.ToCAN())
+				if !ok {
+					c.addWarning(&compileError{def: def, reason: "no declared message"})
+					continue
+				}
+				switch def.AttributeName {
+				case "GenMsgSendType":
+					if err := msg.SendType.UnmarshalString(def.StringValue); err != nil {
+						c.addWarning(&compileError{def: def, reason: err.Error()})
+						continue
+					}
+				case "GenMsgCycleTime":
+					msg.CycleTime = time.Duration(def.IntValue) * time.Millisecond
+				case "GenMsgDelayTime":
+					msg.DelayTime = time.Duration(def.IntValue) * time.Millisecond
+				}
+			case dbc.ObjectTypeSignal:
+				sig, ok := c.db.Signal(def.MessageID.ToCAN(), string(def.SignalName))
+				if !ok {
+					c.addWarning(&compileError{def: def, reason: "no declared signal"})
+				}
+				if def.AttributeName == "GenSigStartValue" {
+					sig.DefaultValue = int(def.IntValue)
+				}
+			}
+		}
+	}
+}
+
+func (c *compiler) sortDescriptors() {
+	// Sort nodes by name
+	sort.Slice(c.db.Nodes, func(i, j int) bool {
+		return c.db.Nodes[i].Name < c.db.Nodes[j].Name
+	})
+	// Sort messages by ID
+	sort.Slice(c.db.Messages, func(i, j int) bool {
+		return c.db.Messages[i].ID < c.db.Messages[j].ID
+	})
+	for _, m := range c.db.Messages {
+		m := m
+		// Sort signals by start (and multiplexer value)
+		sort.Slice(m.Signals, func(j, k int) bool {
+			if m.Signals[j].MultiplexerValue < m.Signals[k].MultiplexerValue {
+				return true
+			}
+			return m.Signals[j].Start < m.Signals[k].Start
+		})
+		// Sort value descriptions by value
+		for _, s := range m.Signals {
+			s := s
+			sort.Slice(s.ValueDescriptions, func(k, l int) bool {
+				return s.ValueDescriptions[k].Value < s.ValueDescriptions[l].Value
+			})
+		}
+	}
+}