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-rw-r--r--vendor/go.opencensus.io/plugin/ochttp/client.go84
1 files changed, 84 insertions, 0 deletions
diff --git a/vendor/go.opencensus.io/plugin/ochttp/client.go b/vendor/go.opencensus.io/plugin/ochttp/client.go
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+++ b/vendor/go.opencensus.io/plugin/ochttp/client.go
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+// 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/trace"
+ "go.opencensus.io/trace/propagation"
+)
+
+// Transport is an http.RoundTripper that instruments all outgoing requests with
+// stats and tracing. The zero value is intended to be a useful default, but for
+// now it's recommended that you explicitly set Propagation.
+type Transport struct {
+ // Base may be set to wrap another http.RoundTripper that does the actual
+ // requests. By default http.DefaultTransport is used.
+ //
+ // If base HTTP roundtripper implements CancelRequest,
+ // the returned round tripper will be cancelable.
+ Base http.RoundTripper
+
+ // Propagation defines how traces are propagated. If unspecified, a default
+ // (currently B3 format) will be used.
+ Propagation propagation.HTTPFormat
+
+ // StartOptions are applied to the span started by this Transport around each
+ // request.
+ //
+ // StartOptions.SpanKind will always be set to trace.SpanKindClient
+ // for spans started by this transport.
+ StartOptions trace.StartOptions
+
+ // TODO: Implement tag propagation for HTTP.
+}
+
+// RoundTrip implements http.RoundTripper, delegating to Base and recording stats and traces for the request.
+func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
+ rt := t.base()
+ // TODO: remove excessive nesting of http.RoundTrippers here.
+ format := t.Propagation
+ if format == nil {
+ format = defaultFormat
+ }
+ rt = &traceTransport{
+ base: rt,
+ format: format,
+ startOptions: trace.StartOptions{
+ Sampler: t.StartOptions.Sampler,
+ SpanKind: trace.SpanKindClient,
+ },
+ }
+ rt = statsTransport{base: rt}
+ return rt.RoundTrip(req)
+}
+
+func (t *Transport) base() http.RoundTripper {
+ if t.Base != nil {
+ return t.Base
+ }
+ return http.DefaultTransport
+}
+
+// CancelRequest cancels an in-flight request by closing its connection.
+func (t *Transport) CancelRequest(req *http.Request) {
+ type canceler interface {
+ CancelRequest(*http.Request)
+ }
+ if cr, ok := t.base().(canceler); ok {
+ cr.CancelRequest(req)
+ }
+}