1// Copyright 2017, OpenCensus Authors 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14// 15 16package ocgrpc 17 18import ( 19 "context" 20 "time" 21 22 "go.opencensus.io/tag" 23 "google.golang.org/grpc/grpclog" 24 "google.golang.org/grpc/stats" 25) 26 27// statsTagRPC gets the tag.Map populated by the application code, serializes 28// its tags into the GRPC metadata in order to be sent to the server. 29func (h *ClientHandler) statsTagRPC(ctx context.Context, info *stats.RPCTagInfo) context.Context { 30 startTime := time.Now() 31 if info == nil { 32 if grpclog.V(2) { 33 grpclog.Info("clientHandler.TagRPC called with nil info.") 34 } 35 return ctx 36 } 37 38 d := &rpcData{ 39 startTime: startTime, 40 method: info.FullMethodName, 41 } 42 ts := tag.FromContext(ctx) 43 if ts != nil { 44 encoded := tag.Encode(ts) 45 ctx = stats.SetTags(ctx, encoded) 46 } 47 48 return context.WithValue(ctx, rpcDataKey, d) 49} 50