redis/pubsub.go

120 lines
2.1 KiB
Go

package redis
import (
"fmt"
"sync"
)
type PubSubClient struct {
*Client
ch chan *Message
once sync.Once
}
func newPubSubClient(client *Client) (*PubSubClient, error) {
pubSubConn, _, err := client.ConnPool.Get()
if err != nil {
return nil, err
}
client.ConnPool.Remove(pubSubConn)
c := &PubSubClient{
Client: &Client{
ConnPool: NewSingleConnPool(pubSubConn),
},
ch: make(chan *Message),
}
return c, nil
}
type Message struct {
Name, Channel, Message string
Number int64
Err error
}
func (c *PubSubClient) consumeMessages() {
conn, err := c.conn()
if err != nil {
panic(err)
}
req := NewMultiBulkReq()
for {
// Replies can arrive in batches.
// Read whole reply and parse messages one by one.
err := c.ReadReply(conn)
if err != nil {
msg := &Message{}
msg.Err = err
c.ch <- msg
return
}
for {
msg := &Message{}
replyI, err := req.ParseReply(conn.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 !conn.Rd.HasUnread() {
break
}
}
}
}
func (c *PubSubClient) Subscribe(channels ...string) (chan *Message, error) {
args := append([]string{"SUBSCRIBE"}, channels...)
req := NewMultiBulkReq(args...)
conn, err := c.conn()
if err != nil {
return nil, err
}
if err := c.WriteReq(req.Req(), conn); err != nil {
return nil, err
}
c.once.Do(func() {
go c.consumeMessages()
})
return c.ch, nil
}
func (c *PubSubClient) Unsubscribe(channels ...string) error {
args := append([]string{"UNSUBSCRIBE"}, channels...)
req := NewMultiBulkReq(args...)
conn, err := c.conn()
if err != nil {
return err
}
return c.WriteReq(req.Req(), conn)
}