1 files changed, 153 insertions, 0 deletions
diff --git a/vendor/go.opentelemetry.io/otel/propagation/propagation.go b/vendor/go.opentelemetry.io/otel/propagation/propagation.go
new file mode 100644
index 000000000..c94438f73
--- /dev/null
+++ b/vendor/go.opentelemetry.io/otel/propagation/propagation.go
@@ -0,0 +1,153 @@
+// 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 propagation // import "go.opentelemetry.io/otel/propagation"
+
+import (
+	"context"
+	"net/http"
+)
+
+// TextMapCarrier is the storage medium used by a TextMapPropagator.
+type TextMapCarrier interface {
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// Get returns the value associated with the passed key.
+	Get(key string) string
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// Set stores the key-value pair.
+	Set(key string, value string)
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// Keys lists the keys stored in this carrier.
+	Keys() []string
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+}
+
+// MapCarrier is a TextMapCarrier that uses a map held in memory as a storage
+// medium for propagated key-value pairs.
+type MapCarrier map[string]string
+
+// Compile time check that MapCarrier implements the TextMapCarrier.
+var _ TextMapCarrier = MapCarrier{}
+
+// Get returns the value associated with the passed key.
+func (c MapCarrier) Get(key string) string {
+	return c[key]
+}
+
+// Set stores the key-value pair.
+func (c MapCarrier) Set(key, value string) {
+	c[key] = value
+}
+
+// Keys lists the keys stored in this carrier.
+func (c MapCarrier) Keys() []string {
+	keys := make([]string, 0, len(c))
+	for k := range c {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
+// HeaderCarrier adapts http.Header to satisfy the TextMapCarrier interface.
+type HeaderCarrier http.Header
+
+// Get returns the value associated with the passed key.
+func (hc HeaderCarrier) Get(key string) string {
+	return http.Header(hc).Get(key)
+}
+
+// Set stores the key-value pair.
+func (hc HeaderCarrier) Set(key string, value string) {
+	http.Header(hc).Set(key, value)
+}
+
+// Keys lists the keys stored in this carrier.
+func (hc HeaderCarrier) Keys() []string {
+	keys := make([]string, 0, len(hc))
+	for k := range hc {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
+// TextMapPropagator propagates cross-cutting concerns as key-value text
+// pairs within a carrier that travels in-band across process boundaries.
+type TextMapPropagator interface {
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// Inject set cross-cutting concerns from the Context into the carrier.
+	Inject(ctx context.Context, carrier TextMapCarrier)
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// Extract reads cross-cutting concerns from the carrier into a Context.
+	Extract(ctx context.Context, carrier TextMapCarrier) context.Context
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// Fields returns the keys whose values are set with Inject.
+	Fields() []string
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+}
+
+type compositeTextMapPropagator []TextMapPropagator
+
+func (p compositeTextMapPropagator) Inject(ctx context.Context, carrier TextMapCarrier) {
+	for _, i := range p {
+		i.Inject(ctx, carrier)
+	}
+}
+
+func (p compositeTextMapPropagator) Extract(ctx context.Context, carrier TextMapCarrier) context.Context {
+	for _, i := range p {
+		ctx = i.Extract(ctx, carrier)
+	}
+	return ctx
+}
+
+func (p compositeTextMapPropagator) Fields() []string {
+	unique := make(map[string]struct{})
+	for _, i := range p {
+		for _, k := range i.Fields() {
+			unique[k] = struct{}{}
+		}
+	}
+
+	fields := make([]string, 0, len(unique))
+	for k := range unique {
+		fields = append(fields, k)
+	}
+	return fields
+}
+
+// NewCompositeTextMapPropagator returns a unified TextMapPropagator from the
+// group of passed TextMapPropagator. This allows different cross-cutting
+// concerns to be propagates in a unified manner.
+//
+// The returned TextMapPropagator will inject and extract cross-cutting
+// concerns in the order the TextMapPropagators were provided. Additionally,
+// the Fields method will return a de-duplicated slice of the keys that are
+// set with the Inject method.
+func NewCompositeTextMapPropagator(p ...TextMapPropagator) TextMapPropagator {
+	return compositeTextMapPropagator(p)
+}