micro/config/source/consul/watcher.go

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2019-05-31 01:11:13 +03:00
package consul
import (
"errors"
"time"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/api/watch"
"github.com/micro/go-micro/config/encoder"
"github.com/micro/go-micro/config/source"
)
type watcher struct {
e encoder.Encoder
name string
stripPrefix string
wp *watch.Plan
ch chan *source.ChangeSet
exit chan bool
}
func newWatcher(key, addr, name, stripPrefix string, e encoder.Encoder) (source.Watcher, error) {
w := &watcher{
e: e,
name: name,
stripPrefix: stripPrefix,
ch: make(chan *source.ChangeSet),
exit: make(chan bool),
}
wp, err := watch.Parse(map[string]interface{}{"type": "keyprefix", "prefix": key})
if err != nil {
return nil, err
}
wp.Handler = w.handle
// wp.Run is a blocking call and will prevent newWatcher from returning
go wp.Run(addr)
w.wp = wp
return w, nil
}
func (w *watcher) handle(idx uint64, data interface{}) {
if data == nil {
return
}
kvs, ok := data.(api.KVPairs)
if !ok {
return
}
d, err := makeMap(w.e, kvs, w.stripPrefix)
if err != nil {
return
}
b, err := w.e.Encode(d)
if err != nil {
return
}
cs := &source.ChangeSet{
Timestamp: time.Now(),
Format: w.e.String(),
Source: w.name,
Data: b,
}
cs.Checksum = cs.Sum()
w.ch <- cs
}
func (w *watcher) Next() (*source.ChangeSet, error) {
select {
case cs := <-w.ch:
return cs, nil
case <-w.exit:
return nil, errors.New("watcher stopped")
}
}
func (w *watcher) Stop() error {
select {
case <-w.exit:
return nil
default:
w.wp.Stop()
close(w.exit)
}
return nil
}