Tarantool + lua-http websockets nonblocking

tarantool-websockets.lua

#!/usr/bin/env tarantool

local cqueues = require "cqueues"
local fiber = require "fiber"
local socket = require "socket"
package.loaded["http.client"] = nil -- tarantool has a namespace clash
local websocket = require "http.websocket"

local cq = cqueues.new()
-- Hook up cqueues loop inside tarantool fiber
fiber.create(function()
	while true do
		local ok, err = cq:step(0)
		if not ok then
			-- Error running cqueues thead. print error and continue
			print(err)
		end
		socket.iowait(cq:pollfd(), cq:events(), cq:timeout())
	end
end)

cq:wrap(function()
	local ws = websocket.new_from_uri("wss://ws-feed.gdax.com")
	assert(ws:connect())
	assert(ws:send([[{"type": "subscribe", "product_id": "BTC-USD"}]]))
	for _=1, 5 do
		local data = assert(ws:receive())
		print(data)
	end
	assert(ws:close())
end)