traefik/integration/vendor/github.com/vdemeester/docker-events/handlers.go

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2017-02-07 21:33:23 +00:00
package events
import (
"sync"
eventtypes "github.com/docker/engine-api/types/events"
)
// NewHandler creates an event handler using the specified function to qualify the message
// and to route it to the correct handler.
func NewHandler(fun func(eventtypes.Message) string) *Handler {
return &Handler{
keyFunc: fun,
handlers: make(map[string]func(eventtypes.Message)),
}
}
// ByType is a qualify function based on message type.
func ByType(e eventtypes.Message) string {
return e.Type
}
// ByAction is a qualify function based on message action.
func ByAction(e eventtypes.Message) string {
return e.Action
}
// Handler is a struct holding the handlers by keys, and the function to get the
// key from the message.
type Handler struct {
keyFunc func(eventtypes.Message) string
handlers map[string]func(eventtypes.Message)
mu sync.Mutex
}
// Handle registers a function has handler for the specified key.
func (w *Handler) Handle(key string, h func(eventtypes.Message)) {
w.mu.Lock()
w.handlers[key] = 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 *Handler) Watch(c <-chan eventtypes.Message) {
for e := range c {
w.mu.Lock()
h, exists := w.handlers[w.keyFunc(e)]
w.mu.Unlock()
if !exists {
continue
}
go h(e)
}
}