-
Notifications
You must be signed in to change notification settings - Fork 0
/
otel.go
100 lines (81 loc) · 2.55 KB
/
otel.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
// Copyright 2023 Igor Zibarev
// Copyright The OpenTelemetry 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
// limitations under the License.
package tracecontext
// Code in this file is taken and adapted from otel-go.
// See: https://github.com/open-telemetry/opentelemetry-go/blob/7c552505a9cb0462d6859cec18bfe9cbac6e38c3/propagation/trace_context.go
import (
"encoding/hex"
"regexp"
"go.opentelemetry.io/otel/trace"
)
const (
maxVersion = 254
)
var traceCtxRegExp = regexp.MustCompile("^(?P<version>[0-9a-f]{2})-(?P<traceID>[a-f0-9]{32})-(?P<spanID>[a-f0-9]{16})-(?P<traceFlags>[a-f0-9]{2})(?:-.*)?$")
func extractTraceparent(src string) trace.SpanContext {
matches := traceCtxRegExp.FindStringSubmatch(src)
if len(matches) == 0 {
return trace.SpanContext{}
}
if len(matches) < 5 { // four subgroups plus the overall match
return trace.SpanContext{}
}
if len(matches[1]) != 2 {
return trace.SpanContext{}
}
ver, err := hex.DecodeString(matches[1])
if err != nil {
return trace.SpanContext{}
}
version := int(ver[0])
if version > maxVersion {
return trace.SpanContext{}
}
if version == 0 && len(matches) != 5 { // four subgroups plus the overall match
return trace.SpanContext{}
}
if len(matches[2]) != 32 {
return trace.SpanContext{}
}
var scc trace.SpanContextConfig
scc.TraceID, err = trace.TraceIDFromHex(matches[2][:32])
if err != nil {
return trace.SpanContext{}
}
if len(matches[3]) != 16 {
return trace.SpanContext{}
}
scc.SpanID, err = trace.SpanIDFromHex(matches[3])
if err != nil {
return trace.SpanContext{}
}
if len(matches[4]) != 2 {
return trace.SpanContext{}
}
opts, err := hex.DecodeString(matches[4])
if err != nil || len(opts) < 1 || (version == 0 && opts[0] > 2) {
return trace.SpanContext{}
}
// Clear all flags other than the trace-context supported sampling bit.
scc.TraceFlags = trace.TraceFlags(opts[0]) & trace.FlagsSampled
sc := trace.NewSpanContext(scc)
if !sc.IsValid() {
return trace.SpanContext{}
}
return sc
}
func extractTracestate(src string) (trace.TraceState, error) {
return trace.ParseTraceState(src)
}