1 files changed, 117 insertions, 0 deletions
diff --git a/vendor/go.opencensus.io/plugin/ochttp/client.go b/vendor/go.opencensus.io/plugin/ochttp/client.go
new file mode 100644
index 000000000..da815b2a7
--- /dev/null
+++ b/vendor/go.opencensus.io/plugin/ochttp/client.go
@@ -0,0 +1,117 @@
+// 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"
+	"net/http/httptrace"
+
+	"go.opencensus.io/trace"
+	"go.opencensus.io/trace/propagation"
+)
+
+// Transport is an http.RoundTripper that instruments all outgoing requests with
+// OpenCensus stats and tracing.
+//
+// The zero value is intended to be a useful default, but for
+// now it's recommended that you explicitly set Propagation, since the default
+// for this may change.
+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
+
+	// GetStartOptions allows to set start options per request. If set,
+	// StartOptions is going to be ignored.
+	GetStartOptions func(*http.Request) trace.StartOptions
+
+	// NameFromRequest holds the function to use for generating the span name
+	// from the information found in the outgoing HTTP Request. By default the
+	// name equals the URL Path.
+	FormatSpanName func(*http.Request) string
+
+	// NewClientTrace may be set to a function allowing the current *trace.Span
+	// to be annotated with HTTP request event information emitted by the
+	// httptrace package.
+	NewClientTrace func(*http.Request, *trace.Span) *httptrace.ClientTrace
+
+	// 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()
+	if isHealthEndpoint(req.URL.Path) {
+		return rt.RoundTrip(req)
+	}
+	// TODO: remove excessive nesting of http.RoundTrippers here.
+	format := t.Propagation
+	if format == nil {
+		format = defaultFormat
+	}
+	spanNameFormatter := t.FormatSpanName
+	if spanNameFormatter == nil {
+		spanNameFormatter = spanNameFromURL
+	}
+
+	startOpts := t.StartOptions
+	if t.GetStartOptions != nil {
+		startOpts = t.GetStartOptions(req)
+	}
+
+	rt = &traceTransport{
+		base:   rt,
+		format: format,
+		startOptions: trace.StartOptions{
+			Sampler:  startOpts.Sampler,
+			SpanKind: trace.SpanKindClient,
+		},
+		formatSpanName: spanNameFormatter,
+		newClientTrace: t.NewClientTrace,
+	}
+	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)
+	}
+}