Publish camera frame

camera/camera.go

@@ -0,0 +1,174 @@
+package camera
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"github.com/avast/retry-go"
+	"github.com/cyrilix/robocar-protobuf/go/events"
+	"github.com/cyrilix/robocar-simulator/simulator"
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes/timestamp"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"net"
+	"time"
+)
+
+func New(publisher Publisher, addressSimulator string) *Gateway {
+	log.Info("run camera camera")
+
+	return &Gateway{
+		address:          addressSimulator,
+		publisher:        publisher,
+	}
+}
+
+/* Simulator interface to publish camera frames into mqtt topic */
+type Gateway struct {
+	cancel           chan interface{}
+
+	address string
+	conn    io.ReadCloser
+
+	publisher Publisher
+}
+
+func (p *Gateway) Start() error {
+	log.Info("connect to simulator")
+	p.cancel = make(chan interface{})
+	msgChan := make(chan *simulator.SimulatorMsg)
+
+	go p.run(msgChan)
+
+	for {
+		select {
+		case msg := <-msgChan:
+			go p.publishFrame(msg)
+		case <-p.cancel:
+			return nil
+		}
+	}
+}
+
+func (p *Gateway) Stop() {
+	log.Info("close simulator gateway")
+	close(p.cancel)
+
+	if err := p.Close(); err != nil {
+		log.Printf("unexpected error while simulator connection is closed: %v", err)
+	}
+}
+
+func (p *Gateway) Close() error {
+	if p.conn == nil {
+		log.Warnln("no connection to close")
+		return nil
+	}
+	if err := p.conn.Close(); err != nil {
+		return fmt.Errorf("unable to close connection to simulator: %v", err)
+	}
+	return nil
+}
+
+func (p *Gateway) run(msgChan chan<- *simulator.SimulatorMsg) {
+	err := retry.Do(func() error {
+		conn, err := connect(p.address)
+		if err != nil {
+			return fmt.Errorf("unable to connect to simulator at %v", p.address)
+		}
+		p.conn = conn
+		return nil
+	},
+		retry.Delay(1*time.Second),
+	)
+	if err != nil {
+		log.Panicf("unable to connect to simulator: %v", err)
+	}
+
+	reader := bufio.NewReader(p.conn)
+
+	err = retry.Do(
+		func() error { return p.listen(msgChan, reader) },
+	)
+	if err != nil {
+		log.Errorf("unable to connect to server: %v", err)
+	}
+}
+
+func (p *Gateway) listen(msgChan chan<- *simulator.SimulatorMsg, reader *bufio.Reader) error {
+	for {
+		rawLine, err := reader.ReadBytes('\n')
+		if err == io.EOF {
+			log.Info("Connection closed")
+			return err
+		}
+		if err != nil {
+			return fmt.Errorf("unable to read response: %v", err)
+		}
+
+		var msg simulator.SimulatorMsg
+		err = json.Unmarshal(rawLine, &msg)
+		if err != nil {
+			log.Errorf("unable to unmarshal simulator msg: %v", err)
+		}
+		if "telemetry" != msg.MsgType {
+			continue
+		}
+		msgChan <- &msg
+	}
+}
+
+func (p *Gateway) publishFrame(msgSim *simulator.SimulatorMsg) {
+	now := time.Now()
+	msg := &events.FrameMessage{
+		Id: &events.FrameRef{
+			Name: "camera",
+			Id:   fmt.Sprintf("%d%03d", now.Unix(), now.Nanosecond()/1000/1000),
+			CreatedAt: &timestamp.Timestamp{
+				Seconds: now.Unix(),
+				Nanos:   int32(now.Nanosecond()),
+			},
+		},
+		Frame: msgSim.Image,
+	}
+
+	payload, err := proto.Marshal(msg)
+	if err != nil {
+		log.Errorf("unable to marshal protobuf message: %v", err)
+	}
+	p.publisher.Publish(&payload)
+}
+
+var connect = func(address string) (io.ReadWriteCloser, error) {
+	conn, err := net.Dial("tcp", address)
+	if err != nil {
+		return nil, fmt.Errorf("unable to connect to %v", address)
+	}
+	return conn, nil
+}
+
+type Publisher interface {
+	Publish(payload *[]byte)
+}
+
+func NewMqttPublisher(client mqtt.Client, topic string) Publisher {
+	return &MqttPublisher{
+		client: client,
+		topic: topic,
+	}
+}
+
+type MqttPublisher struct {
+	client mqtt.Client
+	topic string
+}
+
+func (m *MqttPublisher) Publish(payload *[]byte) {
+	token := m.client.Publish(m.topic, 0, false, *payload)
+	token.WaitTimeout(10 * time.Millisecond)
+	if err := token.Error(); err != nil {
+		log.Errorf("unable to publish frame: %v", err)
+	}
+}

camera/camera_test.go

@@ -0,0 +1,153 @@
+package camera
+
+import (
+	"bufio"
+	"fmt"
+	"github.com/cyrilix/robocar-protobuf/go/events"
+	"github.com/golang/protobuf/proto"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"io/ioutil"
+	"net"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+type MockPublisher struct {
+	muPubEvents     sync.Mutex
+	publishedEvents []*[]byte
+}
+
+func (p *MockPublisher) Publish(payload *[]byte) {
+	p.muPubEvents.Lock()
+	defer p.muPubEvents.Unlock()
+	p.publishedEvents = append(p.publishedEvents, payload)
+}
+
+func (p *MockPublisher) Events() []*[]byte {
+	p.muPubEvents.Lock()
+	defer p.muPubEvents.Unlock()
+	eventsMsg := make([]*[]byte, len(p.publishedEvents), len(p.publishedEvents))
+	copy(eventsMsg, p.publishedEvents)
+	return eventsMsg
+}
+
+func TestPart_ListenEvents(t *testing.T) {
+	connMock := ConnMock{}
+	err := connMock.Listen()
+	if err != nil {
+		t.Errorf("unable to start mock server: %v", err)
+	}
+	defer func() {
+		if err := connMock.Close(); err != nil {
+			t.Errorf("unable to close mock server: %v", err)
+		}
+	}()
+
+
+	publisher := MockPublisher{publishedEvents: make([]*[]byte, 0)}
+
+	part := New(&publisher, connMock.Addr())
+	go func() {
+		err := part.Start()
+		if err != nil {
+			t.Fatalf("unable to start camera simulator: %v", err)
+		}
+	}()
+	defer func() {
+		if err := part.Close(); err != nil {
+			t.Errorf("unable to close camera simulator: %v", err)
+		}
+	}()
+
+	testContent, err := ioutil.ReadFile("testdata/msg.json")
+	lines := strings.Split(string(testContent), "\n")
+
+	for idx, line := range lines {
+		time.Sleep(5 * time.Millisecond)
+		err = connMock.WriteMsg(line)
+		if err != nil {
+			t.Errorf("[line %v/%v] unable to write line: %v", idx+1, len(lines), err)
+		}
+	}
+
+	time.Sleep(10 * time.Millisecond)
+	expectedFrames := 16
+	if len(publisher.Events()) != expectedFrames {
+		t.Errorf("invalid number of frame emmitted: %v, wants %v", len(publisher.Events()), expectedFrames)
+	}
+	for _, byteMsg := range publisher.Events() {
+		var msg events.FrameMessage
+		err = proto.Unmarshal(*byteMsg, &msg)
+		if err != nil {
+			t.Errorf("unable to unmarshal frame msg: %v", err)
+			continue
+		}
+		if msg.GetId() == nil {
+			t.Error("frame msg has not Id")
+		}
+		if len(msg.Frame) < 10 {
+			t.Errorf("[%v] invalid frame image: %v", msg.Id, msg.GetFrame())
+		}
+	}
+}
+
+type ConnMock struct {
+	ln     net.Listener
+	conn   net.Conn
+	muWriter sync.Mutex
+	writer *bufio.Writer
+}
+
+func (c *ConnMock) WriteMsg(p string) (err error) {
+	c.muWriter.Lock()
+	defer c.muWriter.Unlock()
+	_, err = c.writer.WriteString(p + "\n")
+	if err != nil {
+		log.Errorf("unable to write response: %v", err)
+	}
+	if err == io.EOF {
+		log.Info("Connection closed")
+		return err
+	}
+	err = c.writer.Flush()
+	return err
+}
+
+func (c *ConnMock) Listen() error {
+	c.muWriter.Lock()
+	defer c.muWriter.Unlock()
+	ln, err := net.Listen("tcp", "127.0.0.1:")
+	c.ln = ln
+	if err != nil {
+
+		return fmt.Errorf("unable to listen on port: %v", err)
+	}
+
+	go func() {
+		for {
+			c.conn, err = c.ln.Accept()
+			if err != nil && err == io.EOF {
+				log.Infof("connection close: %v", err)
+				break
+			}
+			c.writer = bufio.NewWriter(c.conn)
+		}
+	}()
+	return nil
+}
+
+func (c *ConnMock) Addr() string {
+	return c.ln.Addr().String()
+}
+
+func (c *ConnMock) Close() error {
+	log.Infof("close mock server")
+	err := c.ln.Close()
+	if err != nil {
+		return fmt.Errorf("unable to close mock server: %v", err)
+	}
+	return nil
+}