[fsync] refactor the code and improve documentation

mote/v2/openwrt/package/flukso/luasrc/fsync.lua

@@ -28,6 +28,8 @@ local nixio = require 'nixio'
 nixio.fs    = require 'nixio.fs'
 local uci   = require 'luci.model.uci'.cursor()
 
+local HW_CHECK_OVERRIDE	 = (arg[1] == '-f')
+
 local CTRL_PATH		 = '/var/run/spid/ctrl'
 local CTRL_PATH_IN	 = CTRL_PATH .. '/in'
 local CTRL_PATH_OUT	 = CTRL_PATH .. '/out'
@@ -38,6 +40,39 @@ local POLLIN		= nixio.poll_flags('in')
 local POLL_TIMEOUT_MS	 = 1000
 local MAX_TRIES		 = 5
 
+-- parse and load /etc/config/flukso
+local flukso = uci:get_all('flukso')
+
+local MAX_SENSORS	 = tonumber(flukso.main.max_sensors)
+local MAX_ANALOG_SENSORS = tonumber(flukso.main.max_analog_sensors)
+local RESET_COUNTERS	 = (flukso.main.reset_counters == '1')
+local SYNC_TO_SERVER	 = (flukso.daemon.enable_wan_branch == '1')
+
+local METERCONST_FACTOR	 = 0.449
+
+local GET_HW_VERSION	 = 'gh'
+local GET_HW_VERSION_R	 = '^gh%s+(%d+)%s+(%d+)$'
+local SET_ENABLE	 = 'se %d %d'
+local SET_PHY_TO_LOG	 = 'sp' -- with [1..MAX_SENSORS] arguments
+local SET_METERCONST	 = 'sm %d %d'
+local SET_COUNTER	 = 'sc %d %d'
+local COMMIT		 = 'ct'
+
+local API_PATH		 = '/www/sensor/'
+local CGI_SCRIPT	 = '/usr/bin/restful'
+local AVAHI_PATH	 = '/etc/avahi/services/flukso.service'
+
+
+--- Convert from Lua-style to c-style index.
+-- @param index		Lua-style index startng at 1
+-- @return 		C-style index starting at 0 
+local function toc(index)
+	return index - 1
+end
+
+--- Log exit status to syslog first, then exit.
+-- @param code  	exit status code
+-- @return		none 
 local function exit(code)
 	nixio.openlog('fsync', 'pid')
 
@@ -49,10 +84,13 @@ local function exit(code)
 		level = 'err'
 	end
 
-	nixio.syslog(level, string.format('fync exited with code: %d', code))
+	nixio.syslog(level, string.format('fsync exit status: %d', code))
 	os.exit(code)
 end
 
+--- Create a pair of file descriptors [fd] to the spid control fifo's.
+-- @return		ctrl object containing the fd's, a line-based iterator and poll flags 
+local function ctrl_init()
 	local ctrl = { fdin    = nixio.open(CTRL_PATH_IN, O_RDWR_NONBLOCK),
                        fdout   = nixio.open(CTRL_PATH_OUT, O_RDWR_NONBLOCK),
                        events  = POLLIN,
@@ -74,7 +112,21 @@ end
 	ctrl.fd = ctrl.fdout -- need this entry for nixio.poll
 	ctrl.line = ctrl.fdout:linesource()
 
+	return ctrl
+end
 
+--- Close the spid control fifo's.
+-- @param code  	ctrl object
+-- @return		none 
+local function ctrl_close(ctrl)
+	ctrl.fdin:close()
+	ctrl.fdout:close()
+end
+
+--- Send a command to the control fifo.
+-- @param ctrl  	ctrl object
+-- @param cmd		command to send
+-- @return		none 
 local function send(ctrl, cmd)
 	while ctrl.line() do end -- flush the out fifo
 
@@ -112,33 +164,10 @@ local function send(ctrl, cmd)
 	exit(2) 
 end
 
-local function toc(num)
+--- Check the sensor board hardware version.
-	return num - 1
+-- @param ctrl  	ctrl object
-end
+-- @return		none 
-
+local function check_hw_version(ctrl) 
-
--- parse and load /etc/config/flukso
-local flukso = uci:get_all('flukso')
-
-local HW_CHECK_OVERRIDE = (arg[1] == '-f')
-
-local MAX_SENSORS	 = tonumber(flukso.main.max_sensors)
-local MAX_ANALOG_SENSORS = tonumber(flukso.main.max_analog_sensors)
-local METERCONST_FACTOR	 = 0.449
-
-local GET_HW_VERSION	 = 'gh'
-local GET_HW_VERSION_R	 = '^gh%s+(%d+)%s+(%d+)$'
-local SET_ENABLE	 = 'se %d %d'
-local SET_PHY_TO_LOG	 = 'sp' -- with [1..MAX_SENSORS] arguments
-local SET_METERCONST	 = 'sm %d %d'
-local SET_COUNTER	 = 'sc %d %d'
-local COMMIT		 = 'ct'
-
-local API_PATH		 = '/www/sensor/'
-local CGI_SCRIPT	 = '/usr/bin/restful'
-local AVAHI_PATH	 = '/etc/avahi/services/flukso.service'
-
--- check hardware version
 	local hw_major, hw_minor = send(ctrl, GET_HW_VERSION):match(GET_HW_VERSION_R)
 
 	if hw_major ~= flukso.main.hw_major or hw_minor > flukso.main.hw_minor then
@@ -160,14 +189,22 @@ if hw_major ~= flukso.main.hw_major or hw_minor > flukso.main.hw_minor then
 	else
 		print(string.format('Hardware check (major: %s, minor: %s) .. ok', hw_major, hw_minor))
 	end
+end
 
--- disable all ports
+--- Disable all sensors in the sensor board.
+-- @param ctrl  	ctrl object
+-- @return		none 
+local function disable_all_sensors(ctrl)
 	for i = 1, MAX_SENSORS do
 		local cmd = string.format(SET_ENABLE, toc(i), 0)
 		send(ctrl, cmd)
 	end
+end
 
--- populate phy_to_log
+--- Populate the physical (port) to logical (sensor) map on the sensor board.
+-- @param ctrl  	ctrl object
+-- @return		none 
+local function set_phy_to_log(ctrl)
 	local phy_to_log = {}
 
 	for i = 1, MAX_SENSORS do
@@ -200,8 +237,12 @@ end
 
 	local cmd = SET_PHY_TO_LOG .. ' ' .. table.concat(phy_to_log, ' ', 0)
 	send(ctrl, cmd)
+end
 
--- populate meterconst
+--- Populate each sensor's meterconstant on the sensor board.
+-- @param ctrl  	ctrl object
+-- @return		none 
+local function set_meterconst(ctrl)
 	for i = 1, MAX_SENSORS do
 		local cmd
 
@@ -216,15 +257,19 @@ for i = 1, MAX_SENSORS do
 		elseif flukso[tostring(i)]['class'] == 'pulse'then
 			local meterconst = tonumber(flukso[tostring(i)].constant or "0")
 			cmd = string.format(SET_METERCONST, toc(i), meterconst)
+
 		else
 			cmd = string.format(SET_METERCONST, toc(i), 0)
 		end
 
 		if cmd then send(ctrl,cmd) end
 	end
+end
 
--- populate counter if reset_counters is set
+--- Reset each sensor's counter on the sensor board.
-if flukso.main.reset_counters == '1' then
+-- @param ctrl  	ctrl object
+-- @return		none 
+local function reset_counters(ctrl)
 	for i = 1, MAX_SENSORS do
 		local cmd = string.format(SET_COUNTER, toc(i), 0)
 		send(ctrl, cmd)
@@ -234,22 +279,29 @@ if flukso.main.reset_counters == '1' then
 	uci:commit('flukso')
 end
 
--- enable configured sensors
+--- Activate the enabled sensors on the sensor board.
+-- @param ctrl  	ctrl object
+-- @return		none 
+local function enable_sensors(ctrl)
 	for i = 1, MAX_SENSORS do
 		if flukso[tostring(i)] ~= nil and flukso[tostring(i)].enable == '1' then
 			cmd = string.format(SET_ENABLE, toc(i), 1)
 			send(ctrl, cmd)
 		end
 	end
+end
 
--- commit changes
+--- Commit all changes on the sensor board.
+-- @param ctrl  	ctrl object
+-- @return		none 
+local function commit(ctrl)
 	send(ctrl, COMMIT)
-
+end
--- clean up ctrl port fd's
-ctrl.fdin:close()
-ctrl.fdout:close()
 
 
+--- Map /sensor/xyz endpoints to the cgi script.
+-- @return		none 
+local function create_symlinks()
 	-- make sure /www/sensor exists
 	nixio.fs.mkdirr(API_PATH)
 
@@ -260,7 +312,12 @@ end
 
 	-- generate new symlinks
 	for i = 1, MAX_SENSORS do
-	if flukso[tostring(i)] ~= nil and flukso[tostring(i)].enable == '1' then
+		if flukso[tostring(i)] ~= nil
+			and flukso[tostring(i)].enable == '1'
+			and flukso[tostring(i)].id
+			and flukso[tostring(i)].class ~= 'uart'
+			then
+
 			local sensor_id = flukso[tostring(i)].id
 
 			if sensor_id then
@@ -269,8 +326,11 @@ for i = 1, MAX_SENSORS do
 			end
 		end
 	end
+end
 
--- generate a new flukso.service for avahi
+--- Generate a new flukso.service xml file for the avahi-daemon.
+-- @return		none 
+local function create_avahi_config()
 	avahi = { head = {}, body = {}, tail = {} }
 
 	avahi.head[1] = '<?xml version="1.0" standalone="no"?><!--*-nxml-*-->'
@@ -282,7 +342,12 @@ avahi.head[6] = '    <type>_flukso._tcp</type>'
 	avahi.head[7] = '    <port>8080</port>'
 
 	for i = 1, MAX_SENSORS do
-	if flukso[tostring(i)] ~= nil and flukso[tostring(i)].enable == '1' and flukso[tostring(i)].id then
+		if flukso[tostring(i)] ~= nil
+			and flukso[tostring(i)].enable == '1'
+			and flukso[tostring(i)].id
+			and flukso[tostring(i)].class ~= 'uart'
+			then
+
 			avahi.body[#avahi.body + 1] = string.format('    <txt-record>id%d=%s</txt-record>' , i, flukso[tostring(i)].id)
 		end
 	end
@@ -310,6 +375,37 @@ end
 	for i = 1, #avahi.tail do
 		fd:write(avahi.tail[i] .. '\n')
 	end
+end
+
+
+-- sync config to sensor board
+local ctrl = ctrl_init()
+
+check_hw_version(ctrl)
+disable_all_sensors(ctrl)
+set_phy_to_log(ctrl)
+set_meterconst(ctrl)
+
+if RESET_COUNTERS then
+	reset_counters(ctrl)
+end
+
+enable_sensors(ctrl)
+commit(ctrl)
+
+ctrl_close(ctrl)
+
+
+-- sync config locally
+create_symlinks()
+create_avahi_config()
+
+
+-- sync config to server
+if SYNC_TO_SERVER then
+	-- TODO POST each sensor's parameters to the /sensor/xyz endpoint
+end
+
 
 print(arg[0] .. ' completed successfully. Bye!')
 exit(0)