| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 trace |
| |
| import ( |
| "context" |
| ) |
| |
| import ( |
| "go.opentelemetry.io/otel/baggage" |
| |
| "go.opentelemetry.io/otel/propagation" |
| |
| "go.opentelemetry.io/otel/trace" |
| ) |
| |
| type metadataSupplier struct { |
| metadata map[string]interface{} |
| } |
| |
| var _ propagation.TextMapCarrier = &metadataSupplier{} |
| |
| func (s *metadataSupplier) Get(key string) string { |
| if s.metadata == nil { |
| return "" |
| } |
| item, ok := s.metadata[key].([]string) |
| if !ok { |
| return "" |
| } |
| if len(item) == 0 { |
| return "" |
| } |
| return item[0] |
| } |
| |
| func (s *metadataSupplier) Set(key string, value string) { |
| if s.metadata == nil { |
| s.metadata = map[string]interface{}{} |
| } |
| s.metadata[key] = value |
| } |
| |
| func (s *metadataSupplier) Keys() []string { |
| out := make([]string, 0, len(s.metadata)) |
| for key := range s.metadata { |
| out = append(out, key) |
| } |
| return out |
| } |
| |
| // Inject injects correlation context and span context into the dubbo |
| // metadata object. This function is meant to be used on outgoing |
| // requests. |
| func Inject(ctx context.Context, metadata map[string]interface{}, propagators propagation.TextMapPropagator) { |
| propagators.Inject(ctx, &metadataSupplier{ |
| metadata: metadata, |
| }) |
| } |
| |
| // Extract returns the baggage and span context that |
| // another service encoded in the dubbo metadata object with Inject. |
| // This function is meant to be used on incoming requests. |
| func Extract(ctx context.Context, metadata map[string]interface{}, propagators propagation.TextMapPropagator) (baggage.Baggage, trace.SpanContext) { |
| ctx = propagators.Extract(ctx, &metadataSupplier{ |
| metadata: metadata, |
| }) |
| return baggage.FromContext(ctx), trace.SpanContextFromContext(ctx) |
| } |