aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--ethutil/reactor.go77
-rw-r--r--ethutil/reactor_test.go30
2 files changed, 107 insertions, 0 deletions
diff --git a/ethutil/reactor.go b/ethutil/reactor.go
new file mode 100644
index 000000000..b3f8b9b5b
--- /dev/null
+++ b/ethutil/reactor.go
@@ -0,0 +1,77 @@
+package ethutil
+
+import (
+ "sync"
+)
+
+type ReactorEvent struct {
+ mut sync.Mutex
+ event string
+ chans []chan React
+}
+
+// Post the specified reactor resource on the channels
+// currently subscribed
+func (e *ReactorEvent) Post(react React) {
+ for _, ch := range e.chans {
+ go func(ch chan React) {
+ ch <- react
+ }(ch)
+ }
+}
+
+// Add a subscriber to this event
+func (e *ReactorEvent) Add(ch chan React) {
+ e.chans = append(e.chans, ch)
+}
+
+// Remove a subscriber
+func (e *ReactorEvent) Remove(ch chan React) {
+ for i, c := range e.chans {
+ if c == ch {
+ e.chans = append(e.chans[:i], e.chans[i+1:]...)
+ }
+ }
+}
+
+// Basic reactor resource
+type React struct {
+ Resource interface{}
+}
+
+// The reactor basic engine. Acts as bridge
+// between the events and the subscribers/posters
+type ReactorEngine struct {
+ patterns map[string]*ReactorEvent
+}
+
+func NewReactorEngine() *ReactorEngine {
+ return &ReactorEngine{patterns: make(map[string]*ReactorEvent)}
+}
+
+// Subscribe a channel to the specified event
+func (reactor *ReactorEngine) Subscribe(event string, ch chan React) {
+ ev := reactor.patterns[event]
+ // Create a new event if one isn't available
+ if ev == nil {
+ ev = &ReactorEvent{event: event}
+ reactor.patterns[event] = ev
+ }
+
+ // Add the channel to reactor event handler
+ ev.Add(ch)
+}
+
+func (reactor *ReactorEngine) Unsubscribe(event string, ch chan React) {
+ ev := reactor.patterns[event]
+ if ev != nil {
+ ev.Remove(ch)
+ }
+}
+
+func (reactor *ReactorEngine) Post(event string, resource interface{}) {
+ ev := reactor.patterns[event]
+ if ev != nil {
+ ev.Post(React{Resource: resource})
+ }
+}
diff --git a/ethutil/reactor_test.go b/ethutil/reactor_test.go
new file mode 100644
index 000000000..48c2f0df3
--- /dev/null
+++ b/ethutil/reactor_test.go
@@ -0,0 +1,30 @@
+package ethutil
+
+import "testing"
+
+func TestReactorAdd(t *testing.T) {
+ engine := NewReactorEngine()
+ ch := make(chan React)
+ engine.Subscribe("test", ch)
+ if len(engine.patterns) != 1 {
+ t.Error("Expected patterns to be 1, got", len(engine.patterns))
+ }
+}
+
+func TestReactorEvent(t *testing.T) {
+ engine := NewReactorEngine()
+
+ // Buffer 1, so it doesn't block for this test
+ ch := make(chan React, 1)
+ engine.Subscribe("test", ch)
+ engine.Post("test", "hello")
+
+ value := <-ch
+ if val, ok := value.Resource.(string); ok {
+ if val != "hello" {
+ t.Error("Expected Resource to be 'hello', got", val)
+ }
+ } else {
+ t.Error("Unable to cast")
+ }
+}