diff --git a/basic.go b/basic.go
index 0e92883..d210160 100644
--- a/basic.go
+++ b/basic.go
@@ -221,6 +221,26 @@ func (b *basicBus) Emitter(evtType interface{}, opts ...event.EmitterOpt) (e eve
return
}
+func (b *basicBus) EmitterCount(evtType interface{}) (int, error) {
+ // discern the type of the interface and ensure it's a pointer
+ typ := reflect.TypeOf(evtType)
+ if typ.Kind() != reflect.Ptr {
+ return 0, errors.New("emitterCount called with non-pointer type")
+ }
+ typ = typ.Elem()
+
+ // get the count
+ b.lk.Lock()
+ n, ok := b.nodes[typ]
+ if !ok {
+ b.lk.Unlock()
+ return 0, nil
+ }
+ b.lk.Unlock()
+
+ return int(atomic.LoadInt32(&n.nEmitters)), nil
+}
+
///////////////////////
// NODE
diff --git a/basic_test.go b/basic_test.go
index 8be3d83..a46d97e 100644
--- a/basic_test.go
+++ b/basic_test.go
@@ -8,6 +8,7 @@ import (
"time"
"github.com/libp2p/go-libp2p-testing/race"
+ "github.com/stretchr/testify/require"
)
type EventA struct{}
@@ -89,6 +90,29 @@ func TestSub(t *testing.T) {
}
}
+func TestEmitterCount(t *testing.T) {
+ bus := NewBus()
+ c, err := bus.EmitterCount(new(EventB))
+ require.NoError(t, err)
+ require.Equal(t, 0, c)
+
+ em, err := bus.Emitter(new(EventB))
+ defer em.Close()
+ require.NoError(t, err)
+ c, err = bus.EmitterCount(new(EventB))
+ require.Equal(t, 1, c)
+
+ em2, err := bus.Emitter(new(EventB))
+ defer em2.Close()
+ require.NoError(t, err)
+ c, err = bus.EmitterCount(new(EventB))
+ require.Equal(t, 2, c)
+
+ // test for error
+ _, err = bus.EmitterCount(EventA{})
+ require.Error(t, err)
+}
+
func TestEmitNoSubNoBlock(t *testing.T) {
bus := NewBus()
diff --git a/go.mod b/go.mod
index c98367b..b1cf38a 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/libp2p/go-eventbus
go 1.12
require (
- github.com/libp2p/go-libp2p-core v0.5.0
+ github.com/libp2p/go-libp2p-core v0.5.1-0.20200326052016-dc8b8fa8c504
github.com/libp2p/go-libp2p-testing v0.1.1
-)
+ github.com/stretchr/testify v1.4.0
+)
\ No newline at end of file
diff --git a/go.sum b/go.sum
index 89a6dc4..73ee2a9 100644
--- a/go.sum
+++ b/go.sum
@@ -20,6 +20,7 @@ github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDk
github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495 h1:6IyqGr3fnd0tM3YxipK27TUskaOVUjU2nG45yzwcQKY=
github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -77,6 +78,8 @@ github.com/libp2p/go-libp2p-core v0.3.0 h1:F7PqduvrztDtFsAa/bcheQ3azmNo+Nq7m8hQY
github.com/libp2p/go-libp2p-core v0.3.0/go.mod h1:ACp3DmS3/N64c2jDzcV429ukDpicbL6+TrrxANBjPGw=
github.com/libp2p/go-libp2p-core v0.5.0 h1:FBQ1fpq2Fo/ClyjojVJ5AKXlKhvNc/B6U0O+7AN1ffE=
github.com/libp2p/go-libp2p-core v0.5.0/go.mod h1:49XGI+kc38oGVwqSBhDEwytaAxgZasHhFfQKibzTls0=
+github.com/libp2p/go-libp2p-core v0.5.1-0.20200326052016-dc8b8fa8c504 h1:fFejZlp7mgufxOc+lKGGtJg6LNJARwceBuHuyTQzpU8=
+github.com/libp2p/go-libp2p-core v0.5.1-0.20200326052016-dc8b8fa8c504/go.mod h1:2SngjXPThb990GE6oJMZqMV11LOXSADC7bCgf95w1qI=
github.com/libp2p/go-libp2p-testing v0.0.4 h1:Qev57UR47GcLPXWjrunv5aLIQGO4n9mhI/8/EIrEEFc=
github.com/libp2p/go-libp2p-testing v0.0.4/go.mod h1:gvchhf3FQOtBdr+eFUABet5a4MBLK8jM3V4Zghvmi+E=
github.com/libp2p/go-libp2p-testing v0.1.1 h1:U03z3HnGI7Ni8Xx6ONVZvUFOAzWYmolWf5W5jAOPNmU=
@@ -138,6 +141,7 @@ github.com/multiformats/go-varint v0.0.5/go.mod h1:3Ls8CIEsrijN6+B7PbrXRPxHRPuXS
github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
github.com/smola/gocompat v0.2.0 h1:6b1oIMlUXIpz//VKEDzPVBK8KG7beVwmHIUEBIs/Pns=
@@ -152,6 +156,7 @@ github.com/src-d/envconfig v1.0.0/go.mod h1:Q9YQZ7BKITldTBnoxsE5gOeB5y66RyPXeue/
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
github.com/x-cray/logrus-prefixed-formatter v0.5.2/go.mod h1:2duySbKsL6M18s5GU7VPsoEPHyzalCE06qoARUCeBBE=
go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
@@ -164,6 +169,7 @@ golang.org/x/crypto v0.0.0-20190211182817-74369b46fc67/go.mod h1:6SG95UA2DQfeDnf
golang.org/x/crypto v0.0.0-20190225124518-7f87c0fbb88b/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8 h1:1wopBVtVdWnn03fZelqdXTqk7U7zPQCb+T4rbU9ZEoU=
golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/crypto v0.0.0-20190618222545-ea8f1a30c443 h1:IcSOAf4PyMp3U3XbIEj1/xJ2BjNN2jWv7JoyOsMxXUU=
golang.org/x/crypto v0.0.0-20190618222545-ea8f1a30c443/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
@@ -218,5 +224,6 @@ gopkg.in/src-d/go-cli.v0 v0.0.0-20181105080154-d492247bbc0d/go.mod h1:z+K8VcOYVY
gopkg.in/src-d/go-log.v1 v1.0.1/go.mod h1:GN34hKP0g305ysm2/hctJ0Y8nWP3zxXXJ8GFabTyABE=
gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=