fix: Handle LastConnected on add/remove cache

- Register/Unregister LastConnected on add/remove device cache.
- Update LastConnected for async reading

Signed-off-by: Lindsey Cheng <beckysocute@gmail.com>

internal/cache/devices.go

@@ -12,10 +12,11 @@ import (
 	"sync"
 	"time"
 
+	"github.com/edgexfoundry/device-sdk-go/v3/internal/container"
+
 	bootstrapContainer "github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/container"
-	bootstrapInterfaces "github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/interfaces"
 	"github.com/edgexfoundry/go-mod-bootstrap/v3/di"
-	"github.com/edgexfoundry/go-mod-core-contracts/v3/clients/logger"
+	"github.com/edgexfoundry/go-mod-core-contracts/v3/common"
 	"github.com/edgexfoundry/go-mod-core-contracts/v3/errors"
 	"github.com/edgexfoundry/go-mod-core-contracts/v3/models"
 
@@ -45,6 +46,7 @@ type DeviceCache interface {
 type deviceCache struct {
 	deviceMap     map[string]*models.Device // key is Device name
 	mutex         sync.RWMutex
+	dic           *di.Container
 	lastConnected map[string]gometrics.Gauge
 }
 
@@ -55,31 +57,44 @@ func newDeviceCache(devices []models.Device, dic *di.Container) DeviceCache {
 		dMap[d.Name] = &devices[i]
 	}
 
-	dc = &deviceCache{deviceMap: dMap}
-	metricsManager := bootstrapContainer.MetricsManagerFrom(dic.Get)
-	lc := bootstrapContainer.LoggingClientFrom(dic.Get)
-	lastConnectedMetrics := registerMetric(metricsManager, devices, lc)
+	dc = &deviceCache{deviceMap: dMap, dic: dic}
+	lastConnectedMetrics := make(map[string]gometrics.Gauge)
+	for _, d := range devices {
+		deviceMetric := gometrics.NewGauge()
+		registerMetric(d.Name, deviceMetric, dic)
+		lastConnectedMetrics[d.Name] = deviceMetric
+	}
 	dc.lastConnected = lastConnectedMetrics
 
 	return dc
 }
 
-func registerMetric(metricManager bootstrapInterfaces.MetricsManager, devices []models.Device, lc logger.LoggingClient) map[string]gometrics.Gauge {
-	lastConnected := make(map[string]gometrics.Gauge)
-	metricName := lastConnectedPrefix + ""
-	for _, d := range devices {
-		deviceMetric := gometrics.NewGauge()
-		registeredName := strings.Replace(metricName, deviceNameText, d.Name, 1)
-
-		err := metricManager.Register(registeredName, deviceMetric, nil)
-		if err != nil {
-			lc.Warnf("Unable to register %s metric. Metric will not be reported : %s", registeredName, err.Error())
-		} else {
-			lc.Infof("%s metric has been registered and will be reported (if enabled)", registeredName)
-			lastConnected[d.Name] = deviceMetric
-		}
+func registerMetric(deviceName string, metric interface{}, dic *di.Container) {
+	metricsManager := bootstrapContainer.MetricsManagerFrom(dic.Get)
+	lc := bootstrapContainer.LoggingClientFrom(dic.Get)
+	configuration := container.ConfigurationFrom(dic.Get)
+	if configuration.Service.EnableNameFieldEscape {
+		deviceName = common.URLEncode(deviceName)
 	}
-	return lastConnected
+	registeredName := strings.Replace(lastConnectedPrefix, deviceNameText, deviceName, 1)
+
+	err := metricsManager.Register(registeredName, metric, map[string]string{"device": deviceName})
+	if err != nil {
+		lc.Warnf("Unable to register %s metric. Metric will not be reported : %s", registeredName, err.Error())
+	} else {
+		lc.Infof("%s metric has been registered and will be reported (if enabled)", registeredName)
+	}
+}
+
+func unregisterMetric(deviceName string, dic *di.Container) {
+	metricsManager := bootstrapContainer.MetricsManagerFrom(dic.Get)
+	configuration := container.ConfigurationFrom(dic.Get)
+	if configuration.Service.EnableNameFieldEscape {
+		deviceName = common.URLEncode(deviceName)
+	}
+	registeredName := strings.Replace(lastConnectedPrefix, deviceNameText, deviceName, 1)
+
+	metricsManager.Unregister(registeredName)
 }
 
 // ForName returns a Device with the given device name.
@@ -124,6 +139,11 @@ func (d *deviceCache) add(device models.Device) errors.EdgeX {
 	}
 
 	d.deviceMap[device.Name] = &device
+
+	// register the lastConnected metric for the new added device
+	deviceMetric := gometrics.NewGauge()
+	registerMetric(device.Name, deviceMetric, d.dic)
+	d.lastConnected[device.Name] = deviceMetric
 	return nil
 }
 
@@ -154,6 +174,11 @@ func (d *deviceCache) removeByName(name string) errors.EdgeX {
 	}
 
 	delete(d.deviceMap, name)
+
+	// unregister the lastConnected metric for the removed device
+	unregisterMetric(name, d.dic)
+	delete(d.lastConnected, name)
+
 	return nil
 }
 

internal/cache/devices_test.go

@@ -8,8 +8,12 @@ package cache
 import (
 	"testing"
 
+	"github.com/edgexfoundry/device-sdk-go/v3/internal/config"
+	"github.com/edgexfoundry/device-sdk-go/v3/internal/container"
+
 	bootstrapContainer "github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/container"
 	"github.com/edgexfoundry/go-mod-bootstrap/v3/bootstrap/interfaces/mocks"
+	bootstrapConfig "github.com/edgexfoundry/go-mod-bootstrap/v3/config"
 	"github.com/edgexfoundry/go-mod-bootstrap/v3/di"
 	"github.com/edgexfoundry/go-mod-core-contracts/v3/clients/logger"
 	"github.com/edgexfoundry/go-mod-core-contracts/v3/models"
@@ -42,6 +46,16 @@ func mockDic() *di.Container {
 		bootstrapContainer.LoggingClientInterfaceName: func(get di.Get) interface{} {
 			return logger.NewMockClient()
 		},
+		container.ConfigurationName: func(get di.Get) interface{} {
+			return &config.ConfigurationStruct{
+				Writable: config.WritableInfo{
+					LogLevel: "INFO",
+				},
+				Service: bootstrapConfig.ServiceInfo{
+					EnableNameFieldEscape: true,
+				},
+			}
+		},
 	})
 }
 

pkg/service/async.go

@@ -53,6 +53,9 @@ func (s *deviceService) sendAsyncValues(acv *sdkModels.AsyncValues, working chan
 		<-working
 	}()
 
+	// Update the LastConnected metric in deviceCache
+	cache.Devices().SetLastConnectedByName(acv.DeviceName)
+
 	if len(acv.CommandValues) == 0 {
 		s.lc.Error("Skip sending AsyncValues because the CommandValues is empty.")
 		return