CBG-3637: Stat definitions use a named object for each stat definition

base/stats.go

@@ -16,6 +16,7 @@ import (
 	"fmt"
 	"log"
 	"math"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -785,39 +786,58 @@ type SgwStat struct {
 	statDesc          *prometheus.Desc
 }
 
+// Name returns the fully qualified name of the stat.
+// Currently only used for the stat metadata exporter tool.
 func (s SgwStat) Name() string {
 	return s.statFQN
 }
 
+// Unit returns the units the stat uses for example, seconds.
+// Currently only used for the stat metadata exporter tool.
 func (s SgwStat) Unit() string {
 	return s.unit
 }
 
+// Help returns the help text for the stat.
+// Currently only used for the stat metadata exporter tool.
 func (s SgwStat) Help() string {
 	return s.help
 }
 
+// AddedVersion returns the version of Sync Gateway this stat was added.
+// Currently only used for the stat metadata exporter tool.
 func (s SgwStat) AddedVersion() string {
 	return s.addedVersion
 }
 
+// DeprecatedVersion returns the version of Sync Gateway this stat was deprecated.
+// Currently only used for the stat metadata exporter tool.
 func (s SgwStat) DeprecatedVersion() string {
 	return s.deprecatedVersion
 }
 
+// Stability returns if there is a commitment to keep this stat stable.
+// Currently only used for the stat metadata exporter tool.
 func (s SgwStat) Stability() string {
 	return s.stability
 }
 
+// LabelKeys returns the label keys for the stat in deterministic order.
+// Currently only used for the stat metadata exporter tool.
 func (s SgwStat) LabelKeys() []string {
 	labelKeys := make([]string, 0, len(s.labels))
 	for labelKey := range s.labels {
 		labelKeys = append(labelKeys, labelKey)
 	}
 
+	// Sort the label keys so that the order is deterministic
+	slices.Sort(labelKeys)
+
 	return labelKeys
 }
 
+// ValueTypeString returns the string representation of the prometheus.ValueType
+// Currently only used for the stat metadata exporter tool.
 func (s SgwStat) ValueTypeString() string {
 	switch s.statValueType {
 	case prometheus.CounterValue:

tools/stats-definition-exporter/main.go

@@ -74,15 +74,24 @@ func closeAndLogError(logger *log.Logger, c io.Closer) {
 	}
 }
 
-func getStats(logger *log.Logger) ([]StatDefinition, error) {
+func getStats(logger *log.Logger) (StatDefinitions, error) {
 	globalStats, dbStats, err := registerStats()
 	if err != nil {
 		return nil, fmt.Errorf("could not register stats: %w", err)
 	}
 
-	// Append the db stat definitions on to the global stat definitions
-	stats := traverseAndRetrieveStats(logger, globalStats)
-	stats = append(stats, traverseAndRetrieveStats(logger, dbStats)...)
+	// Get all the stats
+	globalStatsDefinitions := traverseAndRetrieveStats(logger, globalStats)
+	dbStatDefinitions := traverseAndRetrieveStats(logger, dbStats)
+
+	// Merge the two maps
+	stats := make(StatDefinitions, len(globalStatsDefinitions)+len(dbStatDefinitions))
+	for k, v := range globalStatsDefinitions {
+		stats[k] = v
+	}
+	for k, v := range dbStatDefinitions {
+		stats[k] = v
+	}
 
 	return stats, nil
 }
@@ -110,7 +119,7 @@ func registerStats() (*base.GlobalStat, *base.DbStats, error) {
 	return sgStats.GlobalStats, dbStats, nil
 }
 
-func writeStats(stats []StatDefinition, writer io.Writer) error {
+func writeStats(stats StatDefinitions, writer io.Writer) error {
 	encoder := json.NewEncoder(writer)
 
 	encoder.SetIndent("", "\t")

tools/stats-definition-exporter/stat_definition.go

@@ -12,8 +12,10 @@ import (
 	"github.com/couchbase/sync_gateway/base"
 )
 
+// StatDefinitions is a map of the stats fully qualified name to a StatDefinition
+type StatDefinitions map[string]StatDefinition
+
 type StatDefinition struct {
-	Name              string   `json:"name"`                 // The fully qualified name of the stat
 	Unit              string   `json:"unit,omitempty"`       // What units the stat value is using such as seconds.
 	Labels            []string `json:"labels,omitempty"`     // The labels that Prometheus uses to organise some of the stats such as database, collection, etc
 	Help              string   `json:"help,omitempty"`       // A description of what the stat does
@@ -26,7 +28,6 @@ type StatDefinition struct {
 
 func newStatDefinition(stat base.SgwStatWrapper) StatDefinition {
 	return StatDefinition{
-		Name:         stat.Name(),
 		Unit:         stat.Unit(),
 		Labels:       stat.LabelKeys(),
 		Help:         stat.Help(),

tools/stats-definition-exporter/stat_traverser.go

@@ -15,8 +15,8 @@ import (
 	"github.com/couchbase/sync_gateway/base"
 )
 
-func traverseAndRetrieveStats(logger *log.Logger, s any) []StatDefinition {
-	var stats []StatDefinition
+func traverseAndRetrieveStats(logger *log.Logger, s any) StatDefinitions {
+	stats := make(StatDefinitions)
 
 	topLevel := reflect.ValueOf(s)
 	if topLevel.IsNil() {
@@ -40,7 +40,7 @@ func traverseAndRetrieveStats(logger *log.Logger, s any) []StatDefinition {
 		stat := field.Interface()
 		statWrapper, ok := stat.(base.SgwStatWrapper)
 		if ok {
-			stats = append(stats, newStatDefinition(statWrapper))
+			stats[statWrapper.Name()] = newStatDefinition(statWrapper)
 			continue
 		}
 
@@ -56,8 +56,10 @@ func traverseAndRetrieveStats(logger *log.Logger, s any) []StatDefinition {
 			field = values.Value()
 		}
 
-		// Follow to struct down a level
-		stats = append(stats, traverseAndRetrieveStats(logger, field.Interface())...)
+		// Follow to struct down a level and append the stats to the map
+		for k, v := range traverseAndRetrieveStats(logger, field.Interface()) {
+			stats[k] = v
+		}
 	}
 
 	return stats