Add timeout so as not to hang other games when supply calculations overrun.

1 files changed, 16 insertions, 0 deletions

diff --git a/rules.js b/rules.js
index 3a4b767..fcb889a 100644
--- a/rules.js
+++ b/rules.js
@@ -11,6 +11,10 @@ const max = Math.max
 const min = Math.min
 const abs = Math.abs
 
+const TIMEOUT = 500
+
+var timeout = 0
+
 var states = {}
 var game = null
 var view = null
@@ -1165,10 +1169,17 @@ function is_supply_line_blocked(here, next, side) {
 	return false
 }
 
+function check_timeout() {
+	if (Date.now() > timeout)
+		throw new Error("timeout (supply lines are too complicated)")
+}
+
 function trace_supply_highway(here, v) {
 	if (supply_src[here])
 		return true
 
+	check_timeout()
+
 	let has_supply = false
 
 	let save_v = supply_visited[here]
@@ -1216,6 +1227,8 @@ function trace_supply_chain(here, n, range, v) {
 	if (supply_src[here])
 		return true
 
+	check_timeout()
+
 	let has_supply = false
 
 	let save_v = supply_visited[here]
@@ -7376,6 +7389,7 @@ exports.setup = function (seed, scenario, options) {
 }
 
 exports.view = function(state, current) {
+	timeout = Date.now() + TIMEOUT // don't think too long!
 	load_state(state)
 
 	let scenario = current_scenario()
@@ -7439,6 +7453,7 @@ exports.view = function(state, current) {
 }
 
 exports.query = function (state, current, q) {
+	timeout = Date.now() + TIMEOUT // don't think too long!
 	if (q === 'supply') {
 		load_state(state)
 		if (game.buildup) {
@@ -7561,6 +7576,7 @@ exports.resign = function (state, current) {
 }
 
 exports.action = function (state, current, action, arg) {
+	timeout = Date.now() + TIMEOUT // don't think too long!
 	load_state(state)
 	// Object.seal(game) // XXX: don't allow adding properties
 	let S = states[game.state]