Add timing for boxes.save()

mods/boxes/data.lua

@@ -31,6 +31,7 @@ local function bytes_to_string(bytes)
 end
 
 function boxes.save(minp, maxp)
+	local t1 = os.clock()
 	--[[ TODO: save the box in incremental steps to avoid stalling the server. The
 		problem is that we have to iterate over all positions since there is no way
 		to get the metadata of all nodes in an area, although the engine can.
@@ -166,7 +167,15 @@ function boxes.save(minp, maxp)
 	end
 
 	local raw_data = bytes_to_string(flat_data)
-	return minetest.compress(raw_data, "deflate")
+
+	local t2 = os.clock()
+
+	local cc = minetest.compress(raw_data, "deflate")
+
+	local t3 = os.clock()
+	minetest.log("action", "boxes.save: " .. ((t2 - t1) * 100) .. ", " .. ((t3 - t2) * 100))
+
+	return cc
 end
 
 function boxes.load(minp, box_id, player)