From 1eb18eb8ad114db86ae24b90e866888d57caf2d7 Mon Sep 17 00:00:00 2001
From: Natanael Copa <ncopa@alpinelinux.org>
Date: Mon, 17 Sep 2018 19:33:11 +0200
Subject: implement a fifo and delay messages sent via unix socket

prevent to gett banned for flood the irc channels by sending messages
from via a queue.
---
 bot.lua | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 67 insertions(+), 2 deletions(-)

diff --git a/bot.lua b/bot.lua
index 4bd71af..13c9f86 100644
--- a/bot.lua
+++ b/bot.lua
@@ -2,12 +2,53 @@
 local cqueues = require("cqueues")
 local socket = require("cqueues.socket")
 local errno = require("cqueues.errno")
+local condition = require("cqueues.condition")
 
 local loop = cqueues.new()
 
 local host, port, socketpath = ...
 
 
+--------------------------------------------------------------------------------
+-- fifo queue
+
+local fifo = {}
+function fifo.new()
+	local list = {}
+	list.next = list
+	list.prev = list
+	return setmetatable({list = list, condvar = condition.new()}, {__index = fifo})
+end
+
+function fifo:enqueue(data)
+	local node = { data = data}
+	node.next = self.list.next
+	node.prev = self.list
+	self.list.next.prev = node
+	self.list.next = node
+	self:signal()
+	return self
+end
+
+function fifo:dequeue()
+	local node = self.list.prev
+	self.list.prev = node.prev
+	self.list.prev.next = node.next
+	return node.data
+end
+
+function fifo:empty()
+	return self.list == self.list.next
+end
+
+function fifo:signal()
+	self.condvar:signal()
+end
+
+function fifo:getcv()
+	return self.condvar
+end
+
 --------------------------------------------------------------------------------
 -- irc session
 local irc = { callbacks = {} }
@@ -19,7 +60,8 @@ function irc.new(nick, username, password, realname)
 		password = password,
 		realname = realname or "albotty",
 		hooks = {},
-		channels = {}
+		channels = {},
+		msgq = fifo.new()
 	}
 	return setmetatable(self, { __index = irc })
 end
@@ -267,6 +309,25 @@ function irc:loop()
 	until self.conn:eof()
 end
 
+function irc:msgq_loop()
+	while true do
+		self.msgq:getcv():wait()
+		local loop = cqueues.new()
+		loop:wrap(function()
+			while not self.msgq:empty() do
+				local m = self.msgq:dequeue()
+				self:send_chat(m.target, m.message)
+				cqueues.sleep(1.0)
+			end
+		end)
+		loop:loop()
+	end
+end
+
+function irc:enqueue(target, msg)
+	self.msgq:enqueue{target=target, message =msg}
+end
+
 --------------------------------------------------------------------------
 -- sockserver
 
@@ -285,7 +346,7 @@ end
 sockserver.callbacks["/msg"] = function(self, data)
 	local dest,msg = string.match(data or "", "^([^ ]+) (.*)")
 	if dest then
-		self.ircsess:send_chat(dest, msg)
+		self.ircsess:enqueue(dest, msg)
 		return "ok"
 	end
 	return "error: msg format"
@@ -368,6 +429,10 @@ loop:wrap(function()
 	sess:loop()
 end)
 
+loop:wrap(function()
+	sess:msgq_loop()
+end)
+
 loop:wrap(function()
 	srv:loop(loop)
 end)
-- 
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