Fix parsing of metric subtypes (key stype)

pkg/metricstore/api.go

@@ -78,7 +78,7 @@ type APIQueryResponse struct {
 //   - Type + TypeIds: First level of hierarchy (e.g., "cpu" + ["0", "1", "2"])
 //   - SubType + SubTypeIds: Second level of hierarchy (e.g., "core" + ["0", "1"])
 //
-// If Aggregate is true, data from multiple type/subtype IDs will be aggregated according
+// If Aggregate is true, data from multiple type/stype IDs will be aggregated according
 // to the metric's aggregation strategy. Otherwise, separate results are returned for each combination.
 type APIQuery struct {
 	Type        *string      `json:"type,omitempty"`
@@ -174,13 +174,13 @@ func (data *APIMetricData) PadDataWithNull(ms *MemoryStore, from, to int64, metr
 // This is the primary API for retrieving metric data from the memory store. It supports:
 //   - Individual queries via req.Queries
 //   - Batch queries for all nodes via req.ForAllNodes
-//   - Hierarchical selector construction (cluster → host → type → subtype)
+//   - Hierarchical selector construction (cluster → host → type → stype)
 //   - Optional statistics computation (avg, min, max)
 //   - Optional data scaling
 //   - Optional data padding with NaN values
 //
 // The function constructs selectors based on the query parameters and calls MemoryStore.Read()
-// for each selector. If a query specifies Aggregate=false with multiple type/subtype IDs,
+// for each selector. If a query specifies Aggregate=false with multiple type/stype IDs,
 // separate results are returned for each combination.
 //
 // Parameters:

pkg/metricstore/lineprotocol.go

@@ -6,11 +6,11 @@
 // This file implements ingestion of InfluxDB line-protocol metric data received
 // over NATS. Each line encodes one metric sample with the following structure:
 //
-//	<measurement>[,cluster=<c>][,hostname=<h>][,type=<t>][,type-id=<id>][,subtype=<s>][,stype-id=<id>] value=<v> [<timestamp>]
+//	<measurement>[,cluster=<c>][,hostname=<h>][,type=<t>][,type-id=<id>][,stype=<s>][,stype-id=<id>] value=<v> [<timestamp>]
 //
 // The measurement name identifies the metric (e.g. "cpu_load"). Tags provide
 // routing information (cluster, host) and optional sub-device selectors (type,
-// subtype). Only one field is expected per line: "value".
+// stype). Only one field is expected per line: "value".
 //
 // After decoding, each sample is:
 //  1. Written to the in-memory store via ms.WriteToLevel.
@@ -103,7 +103,7 @@ func ReceiveNats(ms *MemoryStore,
 // reorder prepends prefix to buf in-place when buf has enough spare capacity,
 // avoiding an allocation. Falls back to a regular append otherwise.
 //
-// It is used to assemble the "type<type-id>" and "subtype<stype-id>" selector
+// It is used to assemble the "type<type-id>" and "stype<stype-id>" selector
 // strings when the type tag arrives before the type-id tag in the line, so the
 // two byte slices need to be concatenated in tag-declaration order regardless
 // of wire order.
@@ -145,7 +145,7 @@ type decodeState struct {
 	// current line. Reset at the start of each line's tag-decode loop.
 	typeBuf []byte
 
-	// subTypeBuf accumulates the concatenated "subtype"+"stype-id" tag value.
+	// subTypeBuf accumulates the concatenated "stype"+"stype-id" tag value.
 	// Reset at the start of each line's tag-decode loop.
 	subTypeBuf []byte
 
@@ -186,7 +186,7 @@ var decodeStatePool = sync.Pool{
 //   - The Level pointer (host-level node in the metric tree) is cached across
 //     consecutive lines that share the same cluster+host pair to avoid
 //     repeated lock acquisitions on the root and cluster levels.
-//   - []byte→string conversions for type/subtype selectors are cached via
+//   - []byte→string conversions for type/stype selectors are cached via
 //     prevType*/prevSubType* fields because batches typically repeat the same
 //     sub-device identifiers.
 //   - Timestamp parsing tries Second precision first; if that fails it retries
@@ -269,8 +269,8 @@ func DecodeLine(dec *lineprotocol.Decoder,
 				}
 			case "type-id":
 				st.typeBuf = append(st.typeBuf, val...)
-			case "subtype":
+			case "stype":
-				// We cannot be sure that the "subtype" tag comes before the "stype-id" tag:
+				// We cannot be sure that the "stype" tag comes before the "stype-id" tag:
 				if len(st.subTypeBuf) == 0 {
 					st.subTypeBuf = append(st.subTypeBuf, val...)
 				} else {
@@ -291,7 +291,7 @@ func DecodeLine(dec *lineprotocol.Decoder,
 		}
 
 		// subtypes: cache []byte→string conversions; messages in a batch typically
-		// share the same type/subtype so the hit rate is very high.
+		// share the same type/stype so the hit rate is very high.
 		st.selector = st.selector[:0]
 		if len(st.typeBuf) > 0 {
 			if !bytes.Equal(st.typeBuf, st.prevTypeBytes) {