blob: a50671a23682a08b259dfcf20e54953487b84640 [file] [log] [blame]
mpagenkoaf801632020-07-03 10:00:42 +00001// Copyright (c) 2019 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
17// SamplingDecision is returned by the V2 samplers.
18type SamplingDecision struct {
19 Sample bool
20 Retryable bool
21 Tags []Tag
22}
23
24// SamplerV2 is an extension of the V1 samplers that allows sampling decisions
25// be made at different points of the span lifecycle.
26type SamplerV2 interface {
27 OnCreateSpan(span *Span) SamplingDecision
28 OnSetOperationName(span *Span, operationName string) SamplingDecision
29 OnSetTag(span *Span, key string, value interface{}) SamplingDecision
30 OnFinishSpan(span *Span) SamplingDecision
31
32 // Close does a clean shutdown of the sampler, stopping any background
33 // go-routines it may have started.
34 Close()
35}
36
37// samplerV1toV2 wraps legacy V1 sampler into an adapter that make it look like V2.
38func samplerV1toV2(s Sampler) SamplerV2 {
39 if s2, ok := s.(SamplerV2); ok {
40 return s2
41 }
42 type legacySamplerV1toV2Adapter struct {
43 legacySamplerV1Base
44 }
45 return &legacySamplerV1toV2Adapter{
46 legacySamplerV1Base: legacySamplerV1Base{
47 delegate: s.IsSampled,
48 },
49 }
50}
51
52// SamplerV2Base can be used by V2 samplers to implement dummy V1 methods.
53// Supporting V1 API is required because Tracer configuration only accepts V1 Sampler
54// for backwards compatibility reasons.
55// TODO (breaking change) remove this in the next major release
56type SamplerV2Base struct{}
57
58// IsSampled implements IsSampled of Sampler.
59func (SamplerV2Base) IsSampled(id TraceID, operation string) (sampled bool, tags []Tag) {
60 return false, nil
61}
62
63// Close implements Close of Sampler.
64func (SamplerV2Base) Close() {}
65
66// Equal implements Equal of Sampler.
67func (SamplerV2Base) Equal(other Sampler) bool { return false }
68
69// legacySamplerV1Base is used as a base for simple samplers that only implement
70// the legacy isSampled() function that is not sensitive to its arguments.
71type legacySamplerV1Base struct {
72 delegate func(id TraceID, operation string) (sampled bool, tags []Tag)
73}
74
75func (s *legacySamplerV1Base) OnCreateSpan(span *Span) SamplingDecision {
76 isSampled, tags := s.delegate(span.context.traceID, span.operationName)
77 return SamplingDecision{Sample: isSampled, Retryable: false, Tags: tags}
78}
79
80func (s *legacySamplerV1Base) OnSetOperationName(span *Span, operationName string) SamplingDecision {
81 isSampled, tags := s.delegate(span.context.traceID, span.operationName)
82 return SamplingDecision{Sample: isSampled, Retryable: false, Tags: tags}
83}
84
85func (s *legacySamplerV1Base) OnSetTag(span *Span, key string, value interface{}) SamplingDecision {
86 return SamplingDecision{Sample: false, Retryable: true}
87}
88
89func (s *legacySamplerV1Base) OnFinishSpan(span *Span) SamplingDecision {
90 return SamplingDecision{Sample: false, Retryable: true}
91}
92
93func (s *legacySamplerV1Base) Close() {}