ledisdb/client/go/redis/pubsub.go

130 lines
3.2 KiB
Go

// Copyright 2012 Gary Burd
//
// Licensed under the Apache License, Version 2.0 (the "License"): you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.
package redis
import (
"errors"
)
// Subscription represents a subscribe or unsubscribe notification.
type Subscription struct {
// Kind is "subscribe", "unsubscribe", "psubscribe" or "punsubscribe"
Kind string
// The channel that was changed.
Channel string
// The current number of subscriptions for connection.
Count int
}
// Message represents a message notification.
type Message struct {
// The originating channel.
Channel string
// The message data.
Data []byte
}
// PMessage represents a pmessage notification.
type PMessage struct {
// The matched pattern.
Pattern string
// The originating channel.
Channel string
// The message data.
Data []byte
}
// PubSubConn wraps a Conn with convenience methods for subscribers.
type PubSubConn struct {
Conn Conn
}
// Close closes the connection.
func (c PubSubConn) Close() error {
return c.Conn.Close()
}
// Subscribe subscribes the connection to the specified channels.
func (c PubSubConn) Subscribe(channel ...interface{}) error {
c.Conn.Send("SUBSCRIBE", channel...)
return c.Conn.Flush()
}
// PSubscribe subscribes the connection to the given patterns.
func (c PubSubConn) PSubscribe(channel ...interface{}) error {
c.Conn.Send("PSUBSCRIBE", channel...)
return c.Conn.Flush()
}
// Unsubscribe unsubscribes the connection from the given channels, or from all
// of them if none is given.
func (c PubSubConn) Unsubscribe(channel ...interface{}) error {
c.Conn.Send("UNSUBSCRIBE", channel...)
return c.Conn.Flush()
}
// PUnsubscribe unsubscribes the connection from the given patterns, or from all
// of them if none is given.
func (c PubSubConn) PUnsubscribe(channel ...interface{}) error {
c.Conn.Send("PUNSUBSCRIBE", channel...)
return c.Conn.Flush()
}
// Receive returns a pushed message as a Subscription, Message, PMessage or
// error. The return value is intended to be used directly in a type switch as
// illustrated in the PubSubConn example.
func (c PubSubConn) Receive() interface{} {
reply, err := Values(c.Conn.Receive())
if err != nil {
return err
}
var kind string
reply, err = Scan(reply, &kind)
if err != nil {
return err
}
switch kind {
case "message":
var m Message
if _, err := Scan(reply, &m.Channel, &m.Data); err != nil {
return err
}
return m
case "pmessage":
var pm PMessage
if _, err := Scan(reply, &pm.Pattern, &pm.Channel, &pm.Data); err != nil {
return err
}
return pm
case "subscribe", "psubscribe", "unsubscribe", "punsubscribe":
s := Subscription{Kind: kind}
if _, err := Scan(reply, &s.Channel, &s.Count); err != nil {
return err
}
return s
}
return errors.New("redigo: unknown pubsub notification")
}