mesecons: Unify duplicated code

The new comments should help understanding what is going on
to ease maintenance in the long-run.

Co-authored-by: Jude Melton-Houghton <jwmhjwmh@gmail.com>

mesecons/internal.lua

@@ -90,6 +90,16 @@ function mesecon.get_any_rules(node)
 		mesecon.get_any_outputrules(node))
 end
 
+local function get_rules_from_ndef(ndef, node)
+	local rules = ndef and ndef.rules
+	if type(rules) == 'function' then
+		return rules(node)
+	elseif rules then
+		return rules
+	end
+	return mesecon.rules.default
+end
+
 -- Receptors
 -- Nodes that can power mesecons
 function mesecon.is_receptor_on(nodename)
@@ -117,17 +127,7 @@ function mesecon.is_receptor(nodename)
 end
 
 function mesecon.receptor_get_rules(node)
-	local receptor = mesecon.get_receptor(node.name)
-	if receptor then
-		local rules = receptor.rules
-		if type(rules) == 'function' then
-			return rules(node)
-		elseif rules then
-			return rules
-		end
-	end
-
-	return mesecon.rules.default
+	return get_rules_from_ndef(mesecon.get_receptor(node.name), node)
 end
 
 -- Effectors
@@ -157,16 +157,7 @@ function mesecon.is_effector(nodename)
 end
 
 function mesecon.effector_get_rules(node)
-	local effector = mesecon.get_effector(node.name)
-	if effector then
-		local rules = effector.rules
-		if type(rules) == 'function' then
-			return rules(node)
-		elseif rules then
-			return rules
-		end
-	end
-	return mesecon.rules.default
+	return get_rules_from_ndef(mesecon.get_effector(node.name), node)
 end
 
 -- #######################
@@ -330,16 +321,7 @@ function mesecon.get_conductor_off(node_on, rulename)
 end
 
 function mesecon.conductor_get_rules(node)
-	local conductor = mesecon.get_conductor(node.name)
-	if conductor then
-		local rules = conductor.rules
-		if type(rules) == 'function' then
-			return rules(node)
-		elseif rules then
-			return rules
-		end
-	end
-	return mesecon.rules.default
+	return get_rules_from_ndef(mesecon.get_conductor(node.name), node)
 end
 
 -- some more general high-level stuff
@@ -545,46 +527,42 @@ function mesecon.turnoff(pos, link)
 	return true
 end
 
+-- @param getter_function Function that returns nested rules (vectors)
+-- @return The matching rule or `nil`
+local function find_rule_in_rules(pos, rule, getter_function)
+	local r_pos = vector.add(pos, rule)
+	local r_node = mesecon.get_node_force(r_pos)
+	local r_rules = getter_function(r_node)
+	if not r_rules then
+		return
+	end
+
+	local dir = vector.subtract(pos, r_pos)
+	for _, r_rule in ipairs(mesecon.flattenrules(r_rules)) do
+		if vector.equals(dir, r_rule) then
+			-- Other matches are duplicates
+			return r_rule
+		end
+	end
+end
+
 -- Get all linking inputrules of inputnode (effector or conductor) that is connected to
 -- outputnode (receptor or conductor) at position `output` and has an output in direction `rule`
 function mesecon.rules_link_rule_all(output, rule)
-	local input = vector.add(output, rule)
-	local inputnode = mesecon.get_node_force(input)
-	local inputrules = mesecon.get_any_inputrules(inputnode)
-	if not inputrules then
-		return {}
-	end
-	local rules = {}
-
-	for _, inputrule in ipairs(mesecon.flattenrules(inputrules)) do
-		-- Check if input accepts from output
-		if  vector.equals(vector.add(input, inputrule), output) then
-			table.insert(rules, inputrule)
-		end
-	end
-
-	return rules
+	local match = find_rule_in_rules(output, rule, mesecon.get_any_inputrules)
+	return { match }
 end
 
 -- Get all linking outputnodes of outputnode (receptor or conductor) that is connected to
 -- inputnode (effector or conductor) at position `input` and has an input in direction `rule`
 function mesecon.rules_link_rule_all_inverted(input, rule)
-	local output = vector.add(input, rule)
-	local outputnode = mesecon.get_node_force(output)
-	local outputrules = mesecon.get_any_outputrules(outputnode)
-	if not outputrules then
-		return {}
-	end
-	local rules = {}
-
-	for _, outputrule in ipairs(mesecon.flattenrules(outputrules)) do
-		if  vector.equals(vector.add(output, outputrule), input) then
-			table.insert(rules, mesecon.invertRule(outputrule))
-		end
-	end
-	return rules
+	local match = find_rule_in_rules(input, rule, mesecon.get_any_outputrules)
+	return { match and mesecon.invertRule(match) }
 end
 
+-- @param  pos  Node position (a vector) to check
+-- @param  rule Optional. Specific rule (i.e. node side) to check.
+-- @return Returns a list of vectors that power `pos`, or `false` if unpowered.
 function mesecon.is_powered(pos, rule)
 	local node = mesecon.get_node_force(pos)
 	local rules = mesecon.get_any_inputrules(node)
@@ -593,26 +571,15 @@ function mesecon.is_powered(pos, rule)
 	-- List of nodes that send out power to pos
 	local sourcepos = {}
 
-	if not rule then
-		for _, rule in ipairs(mesecon.flattenrules(rules)) do
-			local rulenames = mesecon.rules_link_rule_all_inverted(pos, rule)
-			for _, rname in ipairs(rulenames) do
-				local np = vector.add(pos, rname)
-				local nn = mesecon.get_node_force(np)
-
-				if (mesecon.is_conductor_on(nn, mesecon.invertRule(rname))
-				or mesecon.is_receptor_on(nn.name)) then
-					table.insert(sourcepos, np)
-				end
-			end
-		end
-	else
+	local rules_flat = rule and { rule } or mesecon.flattenrules(rules)
+	for _, rule in ipairs(rules_flat) do
 		local rulenames = mesecon.rules_link_rule_all_inverted(pos, rule)
 		for _, rname in ipairs(rulenames) do
 			local np = vector.add(pos, rname)
 			local nn = mesecon.get_node_force(np)
-			if (mesecon.is_conductor_on (nn, mesecon.invertRule(rname))
-			or mesecon.is_receptor_on (nn.name)) then
+
+			if (mesecon.is_conductor_on(nn, mesecon.invertRule(rname))
+					or mesecon.is_receptor_on(nn.name)) then
 				table.insert(sourcepos, np)
 			end
 		end

mesecons_luacontroller/init.lua

@@ -12,12 +12,12 @@
 -- ports = get_real_port_states(pos): gets if inputs are powered from outside
 -- newport = merge_port_states(state1, state2): just does result = state1 or state2 for every port
 -- set_port(pos, rule, state): activates/deactivates the mesecons according to the port states
--- set_port_states(pos, ports, ignore_overheat): Applies new port states to a Luacontroller at pos
+-- set_port_states(pos, ports): Applies new port states to a Luacontroller at pos
 -- run_inner(pos, code, event): runs code on the controller at pos and event
 -- reset_formspec(pos, code, errmsg): installs new code and prints error messages, without resetting LCID
 -- reset_meta(pos, code, errmsg): performs a software-reset, installs new code and prints error message
 -- run(pos, event): a wrapper for run_inner which gets code & handles errors via reset_meta
--- reset(pos): performs a hardware reset, turns off all ports
+-- resetn(pos): performs a hardware reset, turns off all ports
 --
 -- The Sandbox
 -- The whole code of the controller runs in a sandbox,
@@ -129,15 +129,10 @@ local function clean_port_states(ports)
 	ports.d = ports.d and true or false
 end
 
-local is_controller_burnt
 
-local function set_port_states(pos, ports, ignore_overheat)
+local function set_port_states(pos, ports)
 	local node = minetest.get_node(pos)
 	local name = node.name
-	if not ignore_overheat and is_controller_burnt(name) then
-		return -- Avoid swapping back to a non-burnt node
-	end
-
 	clean_port_states(ports)
 	local vports = minetest.registered_nodes[name].virtual_portstates
 	local new_name = generate_name(ports)
@@ -173,16 +168,6 @@ end
 -----------------
 -- Overheating --
 -----------------
-
--- Overheating factor of deferred tasks (e.g. digilines).
--- Higher values result in faster overheating.
--- See also: settings 'overheat_max' and 'cooldown_time'
-local TASK_HEAT_FACTOR = 0.8
-
-is_controller_burnt = function(node_name)
-	return node_name == (BASENAME .. "_burnt")
-end
-
 local function burn_controller(pos)
 	local node = minetest.get_node(pos)
 	node.name = BASENAME.."_burnt"
@@ -193,10 +178,6 @@ local function burn_controller(pos)
 end
 
 local function overheat(pos)
-	if is_controller_burnt(core.get_node(pos).name) then
-		-- Avoid spamming "Node overheats" log messages.
-		return true
-	end
 	if mesecon.do_overheat(pos) then -- If too hot
 		burn_controller(pos)
 		return true
@@ -469,10 +450,6 @@ local function get_digiline_send(pos, itbl, send_warning)
 	local chan_maxlen = mesecon.setting("luacontroller_digiline_channel_maxlen", 256)
 	local maxlen = mesecon.setting("luacontroller_digiline_maxlen", 50000)
 	return function(channel, msg)
-		if is_controller_burnt(pos) then
-			return false
-		end
-
 		-- NOTE: This runs within string metatable sandbox, so don't *rely* on anything of the form (""):y
 		--        or via anything that could.
 		-- Make sure channel is string, number or boolean
@@ -700,13 +677,6 @@ local function run_inner(pos, code, event)
 	-- Save memory. This may burn the luacontroller if a memory overflow occurs.
 	save_memory(pos, meta, env.mem)
 
-	-- Action queues can escape the sandbox, thus give a harsh penalty.
-	for i = 1, math.floor(#itbl * TASK_HEAT_FACTOR + 0.5) do
-		if overheat(pos) then
-			break
-		end
-	end
-
 	-- Execute deferred tasks
 	for _, v in ipairs(itbl) do
 		local failure = v()
@@ -714,15 +684,13 @@ local function run_inner(pos, code, event)
 			return false, failure
 		end
 	end
-
 	return true, warning
 end
 
 local function reset_formspec(meta, code, errmsg)
-	code = code or ""
 	meta:set_string("code", code)
 	meta:mark_as_private("code")
-	code = minetest.formspec_escape(code)
+	code = minetest.formspec_escape(code or "")
 	errmsg = minetest.formspec_escape(tostring(errmsg or ""))
 	meta:set_string("formspec", "size[12,10]"
 		.."style_type[label,textarea;font=mono]"
@@ -754,11 +722,11 @@ local function run(pos, event)
 end
 
 local function reset(pos)
-	set_port_states(pos, {a=false, b=false, c=false, d=false}, true)
+	set_port_states(pos, {a=false, b=false, c=false, d=false})
 end
 
 local function node_timer(pos)
-	if is_controller_burnt(core.get_node(pos).name) then
+	if minetest.registered_nodes[minetest.get_node(pos).name].is_burnt then
 		return false
 	end
 	run(pos, {type="interrupt"})
@@ -772,7 +740,7 @@ end
 mesecon.queue:add_function("lc_interrupt", function (pos, luac_id, iid)
 	-- There is no luacontroller anymore / it has been reprogrammed / replaced / burnt
 	if (minetest.get_meta(pos):get_int("luac_id") ~= luac_id) then return end
-	if is_controller_burnt(core.get_node(pos).name) then return end
+	if (minetest.registered_nodes[minetest.get_node(pos).name].is_burnt) then return end
 	run(pos, {type="interrupt", iid = iid})
 end)
 
@@ -780,7 +748,7 @@ mesecon.queue:add_function("lc_digiline_relay", function (pos, channel, luac_id,
 	if not digiline then return end
 	-- This check is only really necessary because in case of server crash, old actions can be thrown into the future
 	if (minetest.get_meta(pos):get_int("luac_id") ~= luac_id) then return end
-	if is_controller_burnt(core.get_node(pos).name) then return end
+	if (minetest.registered_nodes[minetest.get_node(pos).name].is_burnt) then return end
 	-- The actual work
 	digiline:receptor_send(pos, digiline.rules.default, channel, msg)
 end)
@@ -961,6 +929,7 @@ minetest.register_node(BASENAME .. "_burnt", {
 		"jeija_microcontroller_sides.png"
 	},
 	inventory_image = "jeija_luacontroller_burnt_top.png",
+	is_burnt = true,
 	paramtype = "light",
 	is_ground_content = false,
 	groups = {dig_immediate=2, not_in_creative_inventory=1},