redis/pubsub.go

108 lines
1.9 KiB
Go

package redis
import (
"fmt"
)
type PubSubClient struct {
*Client
isSubscribed bool
ch chan *Message
}
func NewPubSubClient(connect connectFunc, disconnect disconnectFunc) *PubSubClient {
c := &PubSubClient{
Client: NewClient(connect, disconnect),
ch: make(chan *Message),
}
return c
}
type Message struct {
Name, Channel, Message string
Number int64
Err error
}
func (c *PubSubClient) consumeMessages() {
req := NewMultiBulkReq()
for {
// Replies can arrive in batches.
// Read whole reply and parse messages one by one.
rd, err := c.readerPool.Get()
if err != nil {
msg := &Message{}
msg.Err = err
c.ch <- msg
return
}
defer c.readerPool.Add(rd)
err = c.ReadReply(rd)
if err != nil {
msg := &Message{}
msg.Err = err
c.ch <- msg
return
}
for {
msg := &Message{}
replyI, err := req.ParseReply(rd)
if err != nil {
msg.Err = err
c.ch <- msg
break
}
reply := replyI.([]interface{})
msgName := reply[0].(string)
switch msgName {
case "subscribe", "unsubscribe":
msg.Name = msgName
msg.Channel = reply[1].(string)
msg.Number = reply[2].(int64)
case "message":
msg.Name = msgName
msg.Channel = reply[1].(string)
msg.Message = reply[2].(string)
default:
msg.Err = fmt.Errorf("Unsupported message name: %q.", msgName)
}
c.ch <- msg
if !rd.HasUnread() {
break
}
}
}
}
func (c *PubSubClient) Subscribe(channels ...string) (chan *Message, error) {
args := append([]string{"SUBSCRIBE"}, channels...)
req := NewMultiBulkReq(args...)
if err := c.WriteReq(req.Req()); err != nil {
return nil, err
}
c.mtx.Lock()
if !c.isSubscribed {
c.isSubscribed = true
go c.consumeMessages()
}
c.mtx.Unlock()
return c.ch, nil
}
func (c *PubSubClient) Unsubscribe(channels ...string) error {
args := append([]string{"UNSUBSCRIBE"}, channels...)
req := NewMultiBulkReq(args...)
return c.WriteReq(req.Req())
}