1 // Copyright 2018, 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 package ocgrpc 16 17 import ( 18 "context" 19 20 "go.opencensus.io/trace" 21 "google.golang.org/grpc/stats" 22 ) 23 24 // ClientHandler implements a gRPC stats.Handler for recording OpenCensus stats and 25 // traces. Use with gRPC clients only. 26 type ClientHandler struct { 27 // StartOptions allows configuring the StartOptions used to create new spans. 28 // 29 // StartOptions.SpanKind will always be set to trace.SpanKindClient 30 // for spans started by this handler. 31 StartOptions trace.StartOptions 32 } 33 34 // HandleConn exists to satisfy gRPC stats.Handler. 35 func (c *ClientHandler) HandleConn(ctx context.Context, cs stats.ConnStats) { 36 // no-op 37 } 38 39 // TagConn exists to satisfy gRPC stats.Handler. 40 func (c *ClientHandler) TagConn(ctx context.Context, cti *stats.ConnTagInfo) context.Context { 41 // no-op 42 return ctx 43 } 44 45 // HandleRPC implements per-RPC tracing and stats instrumentation. 46 func (c *ClientHandler) HandleRPC(ctx context.Context, rs stats.RPCStats) { 47 traceHandleRPC(ctx, rs) 48 statsHandleRPC(ctx, rs) 49 } 50 51 // TagRPC implements per-RPC context management. 52 func (c *ClientHandler) TagRPC(ctx context.Context, rti *stats.RPCTagInfo) context.Context { 53 ctx = c.traceTagRPC(ctx, rti) 54 ctx = c.statsTagRPC(ctx, rti) 55 return ctx 56 } 57