Updates for jaeger tracing client.

vendor/github.com/uber/jaeger-client-go/baggage_setter.go

@@ -0,0 +1,77 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// 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
+// limitations under the License.
+
+package jaeger
+
+import (
+	"github.com/opentracing/opentracing-go/log"
+
+	"github.com/uber/jaeger-client-go/internal/baggage"
+)
+
+// baggageSetter is an actor that can set a baggage value on a Span given certain
+// restrictions (eg. maxValueLength).
+type baggageSetter struct {
+	restrictionManager baggage.RestrictionManager
+	metrics            *Metrics
+}
+
+func newBaggageSetter(restrictionManager baggage.RestrictionManager, metrics *Metrics) *baggageSetter {
+	return &baggageSetter{
+		restrictionManager: restrictionManager,
+		metrics:            metrics,
+	}
+}
+
+// (NB) span should hold the lock before making this call
+func (s *baggageSetter) setBaggage(span *Span, key, value string) {
+	var truncated bool
+	var prevItem string
+	restriction := s.restrictionManager.GetRestriction(span.serviceName(), key)
+	if !restriction.KeyAllowed() {
+		s.logFields(span, key, value, prevItem, truncated, restriction.KeyAllowed())
+		s.metrics.BaggageUpdateFailure.Inc(1)
+		return
+	}
+	if len(value) > restriction.MaxValueLength() {
+		truncated = true
+		value = value[:restriction.MaxValueLength()]
+		s.metrics.BaggageTruncate.Inc(1)
+	}
+	prevItem = span.context.baggage[key]
+	s.logFields(span, key, value, prevItem, truncated, restriction.KeyAllowed())
+	span.context = span.context.WithBaggageItem(key, value)
+	s.metrics.BaggageUpdateSuccess.Inc(1)
+}
+
+func (s *baggageSetter) logFields(span *Span, key, value, prevItem string, truncated, valid bool) {
+	if !span.context.IsSampled() {
+		return
+	}
+	fields := []log.Field{
+		log.String("event", "baggage"),
+		log.String("key", key),
+		log.String("value", value),
+	}
+	if prevItem != "" {
+		fields = append(fields, log.String("override", "true"))
+	}
+	if truncated {
+		fields = append(fields, log.String("truncated", "true"))
+	}
+	if !valid {
+		fields = append(fields, log.String("invalid", "true"))
+	}
+	span.logFieldsNoLocking(fields...)
+}