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
|
// Copyright 2018, OpenCensus 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 ochttp
import (
"net/http"
"go.opencensus.io/tag"
)
// WithRouteTag returns an http.Handler that records stats with the
// http_server_route tag set to the given value.
func WithRouteTag(handler http.Handler, route string) http.Handler {
return taggedHandlerFunc(func(w http.ResponseWriter, r *http.Request) []tag.Mutator {
addRoute := []tag.Mutator{tag.Upsert(KeyServerRoute, route)}
ctx, _ := tag.New(r.Context(), addRoute...)
r = r.WithContext(ctx)
handler.ServeHTTP(w, r)
return addRoute
})
}
// taggedHandlerFunc is a http.Handler that returns tags describing the
// processing of the request. These tags will be recorded along with the
// measures in this package at the end of the request.
type taggedHandlerFunc func(w http.ResponseWriter, r *http.Request) []tag.Mutator
func (h taggedHandlerFunc) ServeHTTP(w http.ResponseWriter, r *http.Request) {
tags := h(w, r)
if a, ok := r.Context().Value(addedTagsKey{}).(*addedTags); ok {
a.t = append(a.t, tags...)
}
}
type addedTagsKey struct{}
type addedTags struct {
t []tag.Mutator
}
|
