Initial commit

vendor/github.com/hyperhq/hypercli/cli/command/events_utils.go

@@ -0,0 +1,47 @@
+package command
+
+import (
+	"sync"
+
+	eventtypes "github.com/docker/engine-api/types/events"
+)
+
+type eventProcessor func(eventtypes.Message, error) error
+
+// EventHandler is abstract interface for user to customize
+// own handle functions of each type of events
+type EventHandler interface {
+	Handle(action string, h func(eventtypes.Message))
+	Watch(c <-chan eventtypes.Message)
+}
+
+// InitEventHandler initializes and returns an EventHandler
+func InitEventHandler() EventHandler {
+	return &eventHandler{handlers: make(map[string]func(eventtypes.Message))}
+}
+
+type eventHandler struct {
+	handlers map[string]func(eventtypes.Message)
+	mu       sync.Mutex
+}
+
+func (w *eventHandler) Handle(action string, h func(eventtypes.Message)) {
+	w.mu.Lock()
+	w.handlers[action] = h
+	w.mu.Unlock()
+}
+
+// Watch ranges over the passed in event chan and processes the events based on the
+// handlers created for a given action.
+// To stop watching, close the event chan.
+func (w *eventHandler) Watch(c <-chan eventtypes.Message) {
+	for e := range c {
+		w.mu.Lock()
+		h, exists := w.handlers[e.Action]
+		w.mu.Unlock()
+		if !exists {
+			continue
+		}
+		go h(e)
+	}
+}