lua-ev emulation using socket.select

ev.lua

-- lua-ev emulation using socket.select

local READ, WRITE = 0x01, 0x02;

local timeout = 5;

local Loop = {};

function Loop.new()
	print("Loop:new")
	local loop = { reading = {}, writing = {} };
	function loop:loop()
		local reading, writing = self.reading, self.writing;
		print("loop:loop")
		while #reading + #writing > 0 do
			local readable, writable, err = socket.select(reading, writing, timeout);
			print("select says:", #readable, #writable, err)
			for i=1,#readable do
				local io = readable[i];
				if reading[io] then
					local revents = READ; if writable[io] then revents = revents+WRITE; end
					io.on_io(self, io, revents);
				end
			end
			for i=1,#writable do
				local io = writable[i];
				if writing[io] and not readable[io] then
					io.on_io(self, io, WRITE);
				end
			end
		end
	end
	return loop;
end

local IO = {};

function IO.new(on_io, file_descriptor, revents)
	print("IO.new")
	local io = { READ = revents % 2 == 1, WRITE = revents % 4 >= 2, fd = file_descriptor, on_io = on_io };
	function io:start(loop, is_daemon)
		print("io:start")
		local function add(self, list)
			if not list[self] then
				local n = #list + 1;
				list[self], list[n] = n, self;
			end
		end
		local function remove(self, list)
			if list[self] then
				list[list[self]] = nil; -- TODO shift
				list[self] = nil;
			end
		end
		if self.READ then add(self, loop.reading); end
		if self.WRITE then add(self, loop.writing); end
	end
	function io:stop(loop)
		error("io:stop")
		remove(self, loop.reading);
		remove(self, loop.writing);
	end
	function io:getfd() return file_descriptor; end
	return io;
end

return { Loop = Loop, IO = IO, READ = READ, WRITE = WRITE };