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 trace 16 17 import ( 18 "sync" 19 20 "go.opencensus.io/trace/internal" 21 ) 22 23 // Config represents the global tracing configuration. 24 type Config struct { 25 // DefaultSampler is the default sampler used when creating new spans. 26 DefaultSampler Sampler 27 28 // IDGenerator is for internal use only. 29 IDGenerator internal.IDGenerator 30 31 // MaxAnnotationEventsPerSpan is max number of annotation events per span 32 MaxAnnotationEventsPerSpan int 33 34 // MaxMessageEventsPerSpan is max number of message events per span 35 MaxMessageEventsPerSpan int 36 37 // MaxAnnotationEventsPerSpan is max number of attributes per span 38 MaxAttributesPerSpan int 39 40 // MaxLinksPerSpan is max number of links per span 41 MaxLinksPerSpan int 42 } 43 44 var configWriteMu sync.Mutex 45 46 const ( 47 // DefaultMaxAnnotationEventsPerSpan is default max number of annotation events per span 48 DefaultMaxAnnotationEventsPerSpan = 32 49 50 // DefaultMaxMessageEventsPerSpan is default max number of message events per span 51 DefaultMaxMessageEventsPerSpan = 128 52 53 // DefaultMaxAttributesPerSpan is default max number of attributes per span 54 DefaultMaxAttributesPerSpan = 32 55 56 // DefaultMaxLinksPerSpan is default max number of links per span 57 DefaultMaxLinksPerSpan = 32 58 ) 59 60 // ApplyConfig applies changes to the global tracing configuration. 61 // 62 // Fields not provided in the given config are going to be preserved. 63 func ApplyConfig(cfg Config) { 64 configWriteMu.Lock() 65 defer configWriteMu.Unlock() 66 c := *config.Load().(*Config) 67 if cfg.DefaultSampler != nil { 68 c.DefaultSampler = cfg.DefaultSampler 69 } 70 if cfg.IDGenerator != nil { 71 c.IDGenerator = cfg.IDGenerator 72 } 73 if cfg.MaxAnnotationEventsPerSpan > 0 { 74 c.MaxAnnotationEventsPerSpan = cfg.MaxAnnotationEventsPerSpan 75 } 76 if cfg.MaxMessageEventsPerSpan > 0 { 77 c.MaxMessageEventsPerSpan = cfg.MaxMessageEventsPerSpan 78 } 79 if cfg.MaxAttributesPerSpan > 0 { 80 c.MaxAttributesPerSpan = cfg.MaxAttributesPerSpan 81 } 82 if cfg.MaxLinksPerSpan > 0 { 83 c.MaxLinksPerSpan = cfg.MaxLinksPerSpan 84 } 85 config.Store(&c) 86 } 87