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 package readme 16 17 import ( 18 "context" 19 "log" 20 21 "go.opencensus.io/tag" 22 ) 23 24 func tagsExamples() { 25 ctx := context.Background() 26 27 osKey := tag.MustNewKey("example.com/keys/user-os") 28 userIDKey := tag.MustNewKey("example.com/keys/user-id") 29 30 // START new 31 ctx, err := tag.New(ctx, 32 tag.Insert(osKey, "macOS-10.12.5"), 33 tag.Upsert(userIDKey, "cde36753ed"), 34 ) 35 if err != nil { 36 log.Fatal(err) 37 } 38 // END new 39 40 // START profiler 41 ctx, err = tag.New(ctx, 42 tag.Insert(osKey, "macOS-10.12.5"), 43 tag.Insert(userIDKey, "fff0989878"), 44 ) 45 if err != nil { 46 log.Fatal(err) 47 } 48 tag.Do(ctx, func(ctx context.Context) { 49 // Do work. 50 // When profiling is on, samples will be 51 // recorded with the key/values from the tag map. 52 }) 53 // END profiler 54 } 55