overflow_subscriber/redis/subscriber.go
2017-08-30 11:06:34 +09:00

120 lines
2.6 KiB
Go

package redis
import (
"context"
"log"
channelUtil "git.loafle.net/commons_go/util/channel"
ofSubscriber "git.loafle.net/overflow/overflow_subscriber"
"github.com/garyburd/redigo/redis"
)
type subscribeChannelAction struct {
channelUtil.Action
channel string
cb ofSubscriber.OnSubscribeFunc
}
type Subscriber interface {
ofSubscriber.Subscriber
}
type subscriber struct {
ctx context.Context
conn redis.PubSubConn
subListeners map[string]ofSubscriber.OnSubscribeFunc
isListenSubscriptions bool
subCh chan subscribeChannelAction
}
func New(ctx context.Context, conn redis.Conn) Subscriber {
n := &subscriber{
ctx: ctx,
subListeners: make(map[string]ofSubscriber.OnSubscribeFunc),
isListenSubscriptions: false,
subCh: make(chan subscribeChannelAction),
}
n.conn = redis.PubSubConn{Conn: conn}
go n.listen()
return n
}
func (n *subscriber) listen() {
for {
select {
case sa := <-n.subCh:
switch sa.Type {
case channelUtil.ActionTypeCreate:
_, ok := n.subListeners[sa.channel]
if ok {
log.Fatalf("Subscriber: Subscription of channel[%s] is already exist", sa.channel)
} else {
n.subListeners[sa.channel] = sa.cb
n.conn.Subscribe(sa.channel)
n.listenSubscriptions()
}
break
case channelUtil.ActionTypeDelete:
_, ok := n.subListeners[sa.channel]
if ok {
n.conn.Unsubscribe(sa.channel)
delete(n.subListeners, sa.channel)
} else {
log.Fatalf("Subscriber: Subscription of channel[%s] is not exist", sa.channel)
}
break
}
case <-n.ctx.Done():
log.Println("redis subscriber: Context Done")
n.conn.Close()
return
}
}
}
func (n *subscriber) listenSubscriptions() {
if n.isListenSubscriptions {
return
}
go func() {
for {
switch v := n.conn.Receive().(type) {
case redis.Message:
if cb, ok := n.subListeners[v.Channel]; ok {
cb(v.Channel, string(v.Data))
}
case redis.Subscription:
log.Printf("subscription message: %s: %s %d\n", v.Channel, v.Kind, v.Count)
case error:
log.Println("error pub/sub, delivery has stopped")
return
default:
}
}
}()
n.isListenSubscriptions = true
}
func (n *subscriber) Subscribe(channel string, cb ofSubscriber.OnSubscribeFunc) {
ca := subscribeChannelAction{
channel: channel,
cb: cb,
}
ca.Type = channelUtil.ActionTypeCreate
n.subCh <- ca
}
func (n *subscriber) Unsubscribe(channel string) {
ca := subscribeChannelAction{
channel: channel,
}
ca.Type = channelUtil.ActionTypeDelete
n.subCh <- ca
}