vendor/github.com/aws/aws-sdk-go/aws/csm/enable.go

   1 package csm
   2
   3 import (
   4         "fmt"
   5         "sync"
   6 )
   7
   8 var (
   9         lock sync.Mutex
  10 )
  11
  12 // Client side metric handler names
  13 const (
  14         APICallMetricHandlerName        = "awscsm.SendAPICallMetric"
  15         APICallAttemptMetricHandlerName = "awscsm.SendAPICallAttemptMetric"
  16 )
  17
  18 // Start will start the a long running go routine to capture
  19 // client side metrics. Calling start multiple time will only
  20 // start the metric listener once and will panic if a different
  21 // client ID or port is passed in.
  22 //
  23 //      Example:
  24 //              r, err := csm.Start("clientID", "127.0.0.1:8094")
  25 //              if err != nil {
  26 //                      panic(fmt.Errorf("expected no error, but received %v", err))
  27 //              }
  28 //              sess := session.NewSession()
  29 //              r.InjectHandlers(sess.Handlers)
  30 //
  31 //              svc := s3.New(sess)
  32 //              out, err := svc.GetObject(&s3.GetObjectInput{
  33 //                      Bucket: aws.String("bucket"),
  34 //                      Key: aws.String("key"),
  35 //              })
  36 func Start(clientID string, url string) (*Reporter, error) {
  37         lock.Lock()
  38         defer lock.Unlock()
  39
  40         if sender == nil {
  41                 sender = newReporter(clientID, url)
  42         } else {
  43                 if sender.clientID != clientID {
  44                         panic(fmt.Errorf("inconsistent client IDs. %q was expected, but received %q", sender.clientID, clientID))
  45                 }
  46
  47                 if sender.url != url {
  48                         panic(fmt.Errorf("inconsistent URLs. %q was expected, but received %q", sender.url, url))
  49                 }
  50         }
  51
  52         if err := connect(url); err != nil {
  53                 sender = nil
  54                 return nil, err
  55         }
  56
  57         return sender, nil
  58 }
  59
  60 // Get will return a reporter if one exists, if one does not exist, nil will
  61 // be returned.
  62 func Get() *Reporter {
  63         lock.Lock()
  64         defer lock.Unlock()
  65
  66         return sender
  67 }