From 4dcf45bac0ae093f58590ca1073e73f6d19fe9b8 Mon Sep 17 00:00:00 2001
From: tidwall <joshbaker77@gmail.com>
Date: Sat, 31 Oct 2020 07:30:48 -0700
Subject: [PATCH] Added pub/sub documentation

---
 README.md        | 42 ++++++++++++++++++++++++++++++++++++++++--
 example/clone.go | 10 ++++++++--
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 6909e33..7da477f 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,7 @@ Features
 - Support for pipelining and telnet commands
 - Works with Redis clients such as [redigo](https://github.com/garyburd/redigo), [redis-py](https://github.com/andymccurdy/redis-py), [node_redis](https://github.com/NodeRedis/node_redis), and [jedis](https://github.com/xetorthio/jedis)
 - [TLS Support](#tls-example)
+- Compatible [pub/sub](#pub_sub)
 - Multithreaded
 
 Installing
@@ -35,6 +36,8 @@ Here's a full example of a Redis clone that accepts:
 - SET key value
 - GET key
 - DEL key
+- PUBLISH channel message
+- (P)SUBSCRIBE channel
 - PING
 - QUIT
 
@@ -60,12 +63,47 @@ var addr = ":6380"
 func main() {
 	var mu sync.RWMutex
 	var items = make(map[string][]byte)
+	var ps redcon.PubSub
 	go log.Printf("started server at %s", addr)
 	err := redcon.ListenAndServe(addr,
 		func(conn redcon.Conn, cmd redcon.Command) {
 			switch strings.ToLower(string(cmd.Args[0])) {
 			default:
 				conn.WriteError("ERR unknown command '" + string(cmd.Args[0]) + "'")
+			case "publish":
+				// Publish to all pub/sub subscribers and return the number of
+				// messages that were sent.
+				if len(cmd.Args) != 3 {
+					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
+					return
+				}
+				count := ps.Publish(string(cmd.Args[1]), string(cmd.Args[2]))
+				conn.WriteInt(count)
+			case "subscribe", "psubscribe":
+				// Subscribe to a pub/sub channel. The `Psubscribe` and 
+				// `Subscribe` operations will detach the connection from the 
+				// event handler and manage all network I/O for this connection
+				// in the background.
+				if len(cmd.Args) < 2 {
+					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
+					return
+				}
+				command := strings.ToLower(string(cmd.Args[0]))
+				for i := 1; i < len(cmd.Args); i++ {
+					if command == "psubscribe" {
+						ps.Psubscribe(conn, string(cmd.Args[i]))
+					} else {
+						ps.Subscribe(conn, string(cmd.Args[i]))
+					}
+				}
+			case "detach":
+				hconn := conn.Detach()
+				log.Printf("connection has been detached")
+				go func() {
+					defer hconn.Close()
+					hconn.WriteString("OK")
+					hconn.Flush()
+				}()
 			case "ping":
 				conn.WriteString("PONG")
 			case "quit":
@@ -110,12 +148,12 @@ func main() {
 			}
 		},
 		func(conn redcon.Conn) bool {
-			// use this function to accept or deny the connection.
+			// Use this function to accept or deny the connection.
 			// log.Printf("accept: %s", conn.RemoteAddr())
 			return true
 		},
 		func(conn redcon.Conn, err error) {
-			// this is called when the connection has been closed
+			// This is called when the connection has been closed
 			// log.Printf("closed: %s, err: %v", conn.RemoteAddr(), err)
 		},
 	)
diff --git a/example/clone.go b/example/clone.go
index cac6440..ae97e1d 100644
--- a/example/clone.go
+++ b/example/clone.go
@@ -21,6 +21,8 @@ func main() {
 			default:
 				conn.WriteError("ERR unknown command '" + string(cmd.Args[0]) + "'")
 			case "publish":
+				// Publish to all pub/sub subscribers and return the number of
+				// messages that were sent.
 				if len(cmd.Args) != 3 {
 					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
 					return
@@ -28,6 +30,10 @@ func main() {
 				count := ps.Publish(string(cmd.Args[1]), string(cmd.Args[2]))
 				conn.WriteInt(count)
 			case "subscribe", "psubscribe":
+				// Subscribe to a pub/sub channel. The `Psubscribe` and
+				// `Subscribe` operations will detach the connection from the
+				// event handler and manage all network I/O for this connection
+				// in the background.
 				if len(cmd.Args) < 2 {
 					conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
 					return
@@ -92,12 +98,12 @@ func main() {
 			}
 		},
 		func(conn redcon.Conn) bool {
-			// use this function to accept or deny the connection.
+			// Use this function to accept or deny the connection.
 			// log.Printf("accept: %s", conn.RemoteAddr())
 			return true
 		},
 		func(conn redcon.Conn, err error) {
-			// this is called when the connection has been closed
+			// This is called when the connection has been closed
 			// log.Printf("closed: %s, err: %v", conn.RemoteAddr(), err)
 		},
 	)