micro/router/service/watcher.go
2020-01-19 23:22:41 +00:00

117 lines
1.9 KiB
Go

package service
import (
"io"
"sync"
"time"
"github.com/micro/go-micro/router"
pb "github.com/micro/go-micro/router/service/proto"
)
type watcher struct {
sync.RWMutex
opts router.WatchOptions
resChan chan *router.Event
done chan struct{}
stream pb.Router_WatchService
}
func newWatcher(rsp pb.Router_WatchService, opts router.WatchOptions) (*watcher, error) {
w := &watcher{
opts: opts,
resChan: make(chan *router.Event),
done: make(chan struct{}),
stream: rsp,
}
go func() {
for {
select {
case <-w.done:
return
default:
if err := w.watch(rsp); err != nil {
w.Stop()
return
}
}
}
}()
return w, nil
}
// watchRouter watches router and send events to all registered watchers
func (w *watcher) watch(stream pb.Router_WatchService) error {
var watchErr error
for {
resp, err := stream.Recv()
if err != nil {
if err != io.EOF {
watchErr = err
}
break
}
route := router.Route{
Service: resp.Route.Service,
Address: resp.Route.Address,
Gateway: resp.Route.Gateway,
Network: resp.Route.Network,
Link: resp.Route.Link,
Metric: resp.Route.Metric,
}
event := &router.Event{
Type: router.EventType(resp.Type),
Timestamp: time.Unix(0, resp.Timestamp),
Route: route,
}
select {
case w.resChan <- event:
case <-w.done:
}
}
return watchErr
}
// Next is a blocking call that returns watch result
func (w *watcher) Next() (*router.Event, error) {
for {
select {
case res := <-w.resChan:
switch w.opts.Service {
case res.Route.Service, "*":
return res, nil
default:
continue
}
case <-w.done:
return nil, router.ErrWatcherStopped
}
}
}
// Chan returns event channel
func (w *watcher) Chan() (<-chan *router.Event, error) {
return w.resChan, nil
}
// Stop stops watcher
func (w *watcher) Stop() {
w.Lock()
defer w.Unlock()
select {
case <-w.done:
return
default:
w.stream.Close()
close(w.done)
}
}