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diff --git a/vendor/go.opencensus.io/trace/doc.go b/vendor/go.opencensus.io/trace/doc.go new file mode 100644 index 0000000..04b1ee4 --- /dev/null +++ b/vendor/go.opencensus.io/trace/doc.go | |||
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1 | // Copyright 2017, OpenCensus Authors | ||
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 | |||
15 | /* | ||
16 | Package trace contains support for OpenCensus distributed tracing. | ||
17 | |||
18 | The following assumes a basic familiarity with OpenCensus concepts. | ||
19 | See http://opencensus.io | ||
20 | |||
21 | |||
22 | Exporting Traces | ||
23 | |||
24 | To export collected tracing data, register at least one exporter. You can use | ||
25 | one of the provided exporters or write your own. | ||
26 | |||
27 | trace.RegisterExporter(exporter) | ||
28 | |||
29 | By default, traces will be sampled relatively rarely. To change the sampling | ||
30 | frequency for your entire program, call ApplyConfig. Use a ProbabilitySampler | ||
31 | to sample a subset of traces, or use AlwaysSample to collect a trace on every run: | ||
32 | |||
33 | trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()}) | ||
34 | |||
35 | Be careful about using trace.AlwaysSample in a production application with | ||
36 | significant traffic: a new trace will be started and exported for every request. | ||
37 | |||
38 | Adding Spans to a Trace | ||
39 | |||
40 | A trace consists of a tree of spans. In Go, the current span is carried in a | ||
41 | context.Context. | ||
42 | |||
43 | It is common to want to capture all the activity of a function call in a span. For | ||
44 | this to work, the function must take a context.Context as a parameter. Add these two | ||
45 | lines to the top of the function: | ||
46 | |||
47 | ctx, span := trace.StartSpan(ctx, "example.com/Run") | ||
48 | defer span.End() | ||
49 | |||
50 | StartSpan will create a new top-level span if the context | ||
51 | doesn't contain another span, otherwise it will create a child span. | ||
52 | */ | ||
53 | package trace // import "go.opencensus.io/trace" | ||