1// Copyright (c) 2017 Uber Technologies, Inc.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package jaeger
16
17import (
18	"github.com/opentracing/opentracing-go/log"
19
20	"github.com/uber/jaeger-client-go/internal/baggage"
21)
22
23// baggageSetter is an actor that can set a baggage value on a Span given certain
24// restrictions (eg. maxValueLength).
25type baggageSetter struct {
26	restrictionManager baggage.RestrictionManager
27	metrics            *Metrics
28}
29
30func newBaggageSetter(restrictionManager baggage.RestrictionManager, metrics *Metrics) *baggageSetter {
31	return &baggageSetter{
32		restrictionManager: restrictionManager,
33		metrics:            metrics,
34	}
35}
36
37// (NB) span should hold the lock before making this call
38func (s *baggageSetter) setBaggage(span *Span, key, value string) {
39	var truncated bool
40	var prevItem string
41	restriction := s.restrictionManager.GetRestriction(span.serviceName(), key)
42	if !restriction.KeyAllowed() {
43		s.logFields(span, key, value, prevItem, truncated, restriction.KeyAllowed())
44		s.metrics.BaggageUpdateFailure.Inc(1)
45		return
46	}
47	if len(value) > restriction.MaxValueLength() {
48		truncated = true
49		value = value[:restriction.MaxValueLength()]
50		s.metrics.BaggageTruncate.Inc(1)
51	}
52	prevItem = span.context.baggage[key]
53	s.logFields(span, key, value, prevItem, truncated, restriction.KeyAllowed())
54	span.context = span.context.WithBaggageItem(key, value)
55	s.metrics.BaggageUpdateSuccess.Inc(1)
56}
57
58func (s *baggageSetter) logFields(span *Span, key, value, prevItem string, truncated, valid bool) {
59	if !span.context.IsSampled() {
60		return
61	}
62	fields := []log.Field{
63		log.String("event", "baggage"),
64		log.String("key", key),
65		log.String("value", value),
66	}
67	if prevItem != "" {
68		fields = append(fields, log.String("override", "true"))
69	}
70	if truncated {
71		fields = append(fields, log.String("truncated", "true"))
72	}
73	if !valid {
74		fields = append(fields, log.String("invalid", "true"))
75	}
76	span.logFieldsNoLocking(fields...)
77}
78