local memory		= require "memory"
local device		= require "device"
local stats			= require "stats"
local log			= require "log"
local timer			= require "timer"
local phobos		= require "libmoon"
local pipe			= require "pipe"
local ffi			= require "ffi"
local namespaces 	= require "namespaces"

ffi.cdef[[
	struct counter_t {
		uint64_t c; 
	} counter_t;
]]

local sketch = namespaces:get()

function master(rxPort)
	if not rxPort then
		return log:info("usage: rxPort")
	end
	local rxDev = device.config{
		port = rxPort,
		dropEnable = false
	}
	device.waitForLinks()
	local pipe = pipe:newFastPipe() 
	sketchInit()
	phobos.startTask("counterSlave", rxDev:getRxQueue(0), pipe)
	phobos.startTask("sketchUpdate", pipe)
	phobos.waitForTasks()
end

function sketchInit()
	sketch.skt = memory.alloc("struct counter_t *", ffi.sizeof("struct counter_t"))
	sketch.skt.c = 0
	return skt
end

function sketchUpdate(pipe)
	while phobos.running() do
		local data = ffi.cast("struct counter_t *", pipe:recv())
		sketch.skt.c = sketch.skt.c + data.c
	end
	memory.free(data)
end

function sketchCount()
	return sketch.skt.c
end

function counterSlave(queue, pipe)
	local bufs = memory.bufArray()
	local rxCtr = stats:newDevRxCounter(queue.dev)
	-- to track if we lose packets on the NIC
	local pktCtr = stats:newPktRxCounter("Packets counted", "plain")
	local timer = timer:new(saveInterval)
	local skt = sketch.skt
	local data = memory.alloc("struct counter_t *", ffi.sizeof("struct counter_t"))
	while phobos.running() do
		local rx = queue:tryRecv(bufs, 100)
		for i = 1, rx do
			local buf = bufs[i]
			local size = buf:getSize()
			pktCtr:countPacket(buf)
		end
		if rx > 0 then
			data.c = rx
			pipe:send(data)
		end
		bufs:free(rx)
		rxCtr:update()
		pktCtr:update()
	end
	rxCtr:finalize()
	pktCtr:finalize()
	print("Pipe-relying function counted: " .. tonumber(sketchCount()))

	-- TODO: check the queue's overflow counter to detect lost packets
end

-- vim:ts=4:sw=4:noexpandtab:ai