local condition = require("cqueues.condition")

local fifo = {}

function fifo.new()
	return setmetatable({ cond = condition.new() }, { __index = fifo })
end

function fifo.signal(f)
	f.cond:signal()
end

function fifo.get(f)
	while not f.head do
		f.cond:wait()
	end

	local data = f.head.data
	f.head = f.head.tail
	return data
end

function fifo.put(f, data)
	local tail = f.head
	while tail and tail.tail do tail = tail.tail end
	if tail then
		tail.tail = { data = data }
	else
		f.head = { data = data }
	end
	fifo.signal(f)
end

function fifo.iter(f)
	return function () return fifo.get(f) end
end

return fifo