1 files changed, 110 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/otlptranslator/unit_namer.go b/vendor/github.com/prometheus/otlptranslator/unit_namer.go
new file mode 100644
index 000000000..4bbf93ef9
--- /dev/null
+++ b/vendor/github.com/prometheus/otlptranslator/unit_namer.go
@@ -0,0 +1,110 @@
+// Copyright 2025 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+
+package otlptranslator
+
+import "strings"
+
+// UnitNamer is a helper for building compliant unit names.
+type UnitNamer struct {
+	UTF8Allowed bool
+}
+
+// Build builds a unit name for the specified unit string.
+// It processes the unit by splitting it into main and per components,
+// applying appropriate unit mappings, and cleaning up invalid characters
+// when the whole UTF-8 character set is not allowed.
+func (un *UnitNamer) Build(unit string) string {
+	mainUnit, perUnit := buildUnitSuffixes(unit)
+	if !un.UTF8Allowed {
+		mainUnit, perUnit = cleanUpUnit(mainUnit), cleanUpUnit(perUnit)
+	}
+
+	var u string
+	switch {
+	case mainUnit != "" && perUnit != "":
+		u = mainUnit + "_" + perUnit
+	case mainUnit != "":
+		u = mainUnit
+	default:
+		u = perUnit
+	}
+
+	// Clean up leading and trailing underscores
+	if len(u) > 0 && u[0:1] == "_" {
+		u = u[1:]
+	}
+	if len(u) > 0 && u[len(u)-1:] == "_" {
+		u = u[:len(u)-1]
+	}
+
+	return u
+}
+
+// Retrieve the Prometheus "basic" unit corresponding to the specified "basic" unit.
+// Returns the specified unit if not found in unitMap.
+func unitMapGetOrDefault(unit string) string {
+	if promUnit, ok := unitMap[unit]; ok {
+		return promUnit
+	}
+	return unit
+}
+
+// Retrieve the Prometheus "per" unit corresponding to the specified "per" unit.
+// Returns the specified unit if not found in perUnitMap.
+func perUnitMapGetOrDefault(perUnit string) string {
+	if promPerUnit, ok := perUnitMap[perUnit]; ok {
+		return promPerUnit
+	}
+	return perUnit
+}
+
+// buildUnitSuffixes builds the main and per unit suffixes for the specified unit
+// but doesn't do any special character transformation to accommodate Prometheus naming conventions.
+// Removing trailing underscores or appending suffixes is done in the caller.
+func buildUnitSuffixes(unit string) (mainUnitSuffix, perUnitSuffix string) {
+	// Split unit at the '/' if any
+	unitTokens := strings.SplitN(unit, "/", 2)
+
+	if len(unitTokens) > 0 {
+		// Main unit
+		// Update if not blank and doesn't contain '{}'
+		mainUnitOTel := strings.TrimSpace(unitTokens[0])
+		if mainUnitOTel != "" && !strings.ContainsAny(mainUnitOTel, "{}") {
+			mainUnitSuffix = unitMapGetOrDefault(mainUnitOTel)
+		}
+
+		// Per unit
+		// Update if not blank and doesn't contain '{}'
+		if len(unitTokens) > 1 && unitTokens[1] != "" {
+			perUnitOTel := strings.TrimSpace(unitTokens[1])
+			if perUnitOTel != "" && !strings.ContainsAny(perUnitOTel, "{}") {
+				perUnitSuffix = perUnitMapGetOrDefault(perUnitOTel)
+			}
+			if perUnitSuffix != "" {
+				perUnitSuffix = "per_" + perUnitSuffix
+			}
+		}
+	}
+
+	return mainUnitSuffix, perUnitSuffix
+}
+
+// cleanUpUnit cleans up unit so it matches model.LabelNameRE.
+func cleanUpUnit(unit string) string {
+	// Multiple consecutive underscores are replaced with a single underscore.
+	// This is part of the OTel to Prometheus specification: https://github.com/open-telemetry/opentelemetry-specification/blob/v1.38.0/specification/compatibility/prometheus_and_openmetrics.md#otlp-metric-points-to-prometheus.
+	return strings.TrimPrefix(multipleUnderscoresRE.ReplaceAllString(
+		strings.Map(replaceInvalidMetricChar, unit),
+		"_",
+	), "_")
+}