From 1a625bc4441987e07538f35deba964110427febf Mon Sep 17 00:00:00 2001
From: Thomas Rudin <thomas@rudin.io>
Date: Tue, 21 Jan 2020 18:20:47 +0100
Subject: [PATCH] clamp radiation damage abm to 100 calls per second max

---
 technic/radiation.lua     |  5 ++++-
 technic/util/throttle.lua | 26 ++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)
 create mode 100644 technic/util/throttle.lua

diff --git a/technic/radiation.lua b/technic/radiation.lua
index 61b7215..f2897cc 100644
--- a/technic/radiation.lua
+++ b/technic/radiation.lua
@@ -28,6 +28,9 @@ or complex internal structure should show no radiation resistance.
 Fractional resistance values are permitted.
 --]]
 
+local MP = minetest.get_modpath("technic")
+local throttle = dofile(MP .. "/util/throttle.lua")
+
 local S = technic.getter
 
 local rad_resistance_node = {
@@ -362,7 +365,7 @@ if minetest.settings:get_bool("enable_damage") then
 		nodenames = {"group:radioactive"},
 		interval = 1,
 		chance = 2,
-		action = dmg_abm,
+		action = throttle(100, dmg_abm),
 	})
 
 	if longterm_damage then
diff --git a/technic/util/throttle.lua b/technic/util/throttle.lua
new file mode 100644
index 0000000..99d4ec2
--- /dev/null
+++ b/technic/util/throttle.lua
@@ -0,0 +1,26 @@
+
+local function throttle(callspersecond, fn)
+	local time = 0
+	local count = 0
+
+	return function(...)
+		local now = minetest.get_us_time()
+		if (now - time) > 1000000 then
+			-- reset time
+			time = now
+			count = 0
+		else
+			-- check max calls
+			count = count + 1
+			if count > callspersecond then
+				return
+			end
+		end
+
+		return pcall(fn, ...)
+	end
+
+end
+
+
+return throttle