vendor/go.opencensus.io/trace/config.go

   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
  32 var configWriteMu sync.Mutex
  33
  34 // ApplyConfig applies changes to the global tracing configuration.
  35 //
  36 // Fields not provided in the given config are going to be preserved.
  37 func ApplyConfig(cfg Config) {
  38         configWriteMu.Lock()
  39         defer configWriteMu.Unlock()
  40         c := *config.Load().(*Config)
  41         if cfg.DefaultSampler != nil {
  42                 c.DefaultSampler = cfg.DefaultSampler
  43         }
  44         if cfg.IDGenerator != nil {
  45                 c.IDGenerator = cfg.IDGenerator
  46         }
  47         config.Store(&c)
  48 }