General code optimisations. (#16)

* General code optimisations.

monitoring/helpers.go

@@ -12,17 +12,14 @@ import (
 	libpack_config "github.com/lukaszraczylo/graphql-monitoring-proxy/config"
 )
 
-// Cache for sorted label keys to avoid repeated sorting
 var sortedLabelKeysCache = struct {
-	m map[string][]string
-	sync.RWMutex
-}{m: make(map[string][]string)}
+	m sync.Map
+}{}
 
 func (ms *MetricsSetup) get_metrics_name(name string, labels map[string]string) string {
 	const unknownPodName = "unknown"
 	var buf bytes.Buffer
 
-	// Prepare default labels without initializing a new map
 	podName := getPodName()
 	if labels == nil {
 		labels = defaultLabels(podName)
@@ -30,18 +27,16 @@ func (ms *MetricsSetup) get_metrics_name(name string, labels map[string]string)
 		ensureDefaultLabels(&labels, podName)
 	}
 
-	// Prefix handling
 	if ms.metrics_prefix != "" {
 		buf.WriteString(ms.metrics_prefix)
-		buf.WriteString("_")
+		buf.WriteByte('_')
 	}
 	buf.WriteString(name)
 
-	// Append labels if any
 	if len(labels) > 0 {
-		buf.WriteString("{")
+		buf.WriteByte('{')
 		appendSortedLabels(&buf, labels)
-		buf.WriteString("}")
+		buf.WriteByte('}')
 	}
 
 	return buf.String()
@@ -78,34 +73,30 @@ func appendSortedLabels(buf *bytes.Buffer, labels map[string]string) {
 	keys := getSortedKeys(labels)
 	for i, k := range keys {
 		if i > 0 {
-			buf.WriteString(",")
+			buf.WriteByte(',')
 		}
 		buf.WriteString(k)
-		buf.WriteString("=\"")
+		buf.WriteString(`="`)
 		buf.WriteString(labels[k])
-		buf.WriteString("\"")
+		buf.WriteByte('"')
 	}
 }
 
 func getSortedKeys(labels map[string]string) []string {
 	labelsKey := labelsToString(labels)
 
-	sortedLabelKeysCache.RLock()
-	keys, exists := sortedLabelKeysCache.m[labelsKey]
-	sortedLabelKeysCache.RUnlock()
-
-	if !exists {
-		keys = make([]string, 0, len(labels))
-		for k := range labels {
-			keys = append(keys, k)
-		}
-		sort.Strings(keys)
-
-		sortedLabelKeysCache.Lock()
-		sortedLabelKeysCache.m[labelsKey] = keys
-		sortedLabelKeysCache.Unlock()
+	if keys, ok := sortedLabelKeysCache.m.Load(labelsKey); ok {
+		return keys.([]string)
 	}
 
+	keys := make([]string, 0, len(labels))
+	for k := range labels {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	sortedLabelKeysCache.m.Store(labelsKey, keys)
+
 	return keys
 }
 
@@ -113,29 +104,24 @@ func labelsToString(labels map[string]string) string {
 	var sb strings.Builder
 	for k, v := range labels {
 		sb.WriteString(k)
-		sb.WriteString("=")
+		sb.WriteByte('=')
 		sb.WriteString(v)
-		sb.WriteString(";")
+		sb.WriteByte(';')
 	}
 	return sb.String()
 }
 
-// validate_metrics_name validates the name of the metric to adhere to the Prometheus naming conventions
-// https://prometheus.io/docs/practices/naming/
 func validate_metrics_name(name string) error {
 	cleanedName := clean_metric_name(name)
 
-	// Trim leading and trailing underscores
 	finalName := strings.Trim(cleanedName, "_")
 
-	// Check if the processed name matches the original input
 	if finalName != name {
-		return fmt.Errorf("Invalid metric name: %s, expected %s", name, finalName)
+		return fmt.Errorf("invalid metric name: %s, expected %s", name, finalName)
 	}
 	return nil
 }
 
-// clean_metric_name processes the metric name according to Prometheus naming conventions
 func clean_metric_name(name string) string {
 	var buf bytes.Buffer
 	lastWasUnderscore := false
@@ -144,31 +130,27 @@ func clean_metric_name(name string) string {
 		if is_allowed_rune(r) {
 			if is_special_rune(r) {
 				if lastWasUnderscore {
-					continue // Skip if the previous character was also an underscore
+					continue
 				}
-				r = '_' // Convert spaces and special characters to underscores
+				r = '_'
 				lastWasUnderscore = true
 			} else {
 				lastWasUnderscore = false
 			}
 			buf.WriteRune(r)
 		} else if !lastWasUnderscore {
-			buf.WriteRune('_')
+			buf.WriteByte('_')
 			lastWasUnderscore = true
 		}
 	}
 
-	// Remove trailing underscore
-	result := buf.String()
-	return strings.Trim(result, "_")
+	return strings.Trim(buf.String(), "_")
 }
 
-// is_allowed_rune checks if the rune is allowed in the metric name
 func is_allowed_rune(r rune) bool {
 	return unicode.IsLetter(r) || unicode.IsDigit(r) || r == ' ' || r == '_'
 }
 
-// is_special_rune checks if the rune is a space or an underscore
 func is_special_rune(r rune) bool {
 	return r == ' ' || r == '_'
 }
@@ -178,14 +160,12 @@ func compile_metrics_with_labels(name string, labels map[string]string) string {
 
 	buf.WriteString(name)
 
-	// Collect keys and sort them
 	keys := getSortedKeys(labels)
 
-	// Append sorted key-value pairs to the buffer
 	for _, k := range keys {
-		buf.WriteString("_")
+		buf.WriteByte('_')
 		buf.WriteString(k)
-		buf.WriteString("_")
+		buf.WriteByte('_')
 		buf.WriteString(labels[k])
 	}