fix/use UNSUPPORTED to represent undefined procotol in labelConvert…

…er (#212)

* fix: avoid to use undefined Protocol

Signed-off-by: niejiangang <niejiangang@harmonycloud.cn>

* fix: add return if exporter is not support trace

Signed-off-by: niejiangang <niejiangang@harmonycloud.cn>

* docs(labelConverter): add comments for `withExtraLabels` function

Signed-off-by: niejiangang <niejiangang@harmonycloud.cn>

* refactor: exact a method for finding extraLabels

Signed-off-by: niejiangang <niejiangang@harmonycloud.cn>

collector/consumer/exporter/otelexporter/consume.go

@@ -54,6 +54,7 @@ func (e *OtelExporter) Export(results []*defaultadapter.AdaptedResult) {
 func (e *OtelExporter) exportTrace(result *defaultadapter.AdaptedResult) {
 	if e.defaultTracer == nil {
 		e.telemetry.Logger.Error("Send span failed: this exporter doesn't support Span Data", zap.String("exporter", e.cfg.ExportKind))
+		return
 	}
 	_, span := e.defaultTracer.Start(
 		context.Background(),

collector/consumer/exporter/otelexporter/defaultadapter/label_converter.go

@@ -139,6 +139,10 @@ func newAdapterBuilder(
 	}
 }
 
+// withExtraLabels determine the final output structure according to some fields in the input data adjustment
+// params provide a list of extraLabelsParam  contain all possible final output structure and a unique key
+// update provide a updateKey func to general a extraLabelsKey key from input data
+// avoid the situation where the key generated by updateKey is undefined in params
 func (m *metricAdapterBuilder) withExtraLabels(params []extraLabelsParam, update updateKey) *metricAdapterBuilder {
 	if m.extraLabelsKey == nil || len(m.extraLabelsKey) == 0 {
 		m.extraLabelsKey = make([]extraLabelsKey, len(params))
@@ -272,11 +276,7 @@ func (m *metricAdapterBuilder) build() (*LabelConverter, error) {
 // transform is used to general final labels for Async Metric.It won't modify the origin model.GaugeGroup and should be free by calling the FreeAttrsMap after exported.
 func (m *LabelConverter) transform(group *model.GaugeGroup) (*model.AttributeMap, FreeAttrsMap) {
 	labels := group.Labels
-	tmpExtraKey := &extraLabelsKey{protocol: empty}
-	for i := 0; i < len(m.updateKeys); i++ {
-		tmpExtraKey = m.updateKeys[i](tmpExtraKey, labels)
-	}
-	attrs := m.labelsMap[*tmpExtraKey]
+	attrs := m.searchExtraAttribute(labels)
 	attrsMap := attrs.attrsMapPool.Get().(*model.AttributeMap)
 	for i := 0; i < len(attrs.metricsDicList); i++ {
 		switch attrs.metricsDicList[i].valueType {
@@ -313,14 +313,25 @@ func (m *LabelConverter) transform(group *model.GaugeGroup) (*model.AttributeMap
 	return attrsMap, attrs.attrsMapPool.Free
 }
 
-// convert is used to general final labels for Sync Metric and Trace. It won't modify the origin model.GaugeGroup and should be free by calling the FreeAttrsList after exported.
-func (m *LabelConverter) convert(group *model.GaugeGroup) ([]attribute.KeyValue, FreeAttrsList) {
-	labels := group.Labels
+// searchExtraAttribute determine the final outPut struct for incoming gaugeGroup
+// return the default struct of `UNSUPPORTED Protocol` if failed
+func (m *LabelConverter) searchExtraAttribute(labels *model.AttributeMap) realAttributes {
 	tmpExtraKey := &extraLabelsKey{protocol: empty}
 	for i := 0; i < len(m.updateKeys); i++ {
 		tmpExtraKey = m.updateKeys[i](tmpExtraKey, labels)
 	}
-	attrs := m.labelsMap[*tmpExtraKey]
+	attrs, ok := m.labelsMap[*tmpExtraKey]
+	if !ok {
+		tmpExtraKey.protocol = UNSUPPORTED
+		attrs = m.labelsMap[*tmpExtraKey]
+	}
+	return attrs
+}
+
+// convert is used to general final labels for Sync Metric and Trace. It won't modify the origin model.GaugeGroup and should be free by calling the FreeAttrsList after exported.
+func (m *LabelConverter) convert(group *model.GaugeGroup) ([]attribute.KeyValue, FreeAttrsList) {
+	labels := group.Labels
+	attrs := m.searchExtraAttribute(group.Labels)
 	attrsList := attrs.attrsListPool.Get().([]attribute.KeyValue)
 	for i := 0; i < len(attrs.metricsDicList); i++ {
 		switch attrs.metricsDicList[i].valueType {