File

spec/util_throttle_spec.lua @ 13130:0b650a54ff9a

doc/hgrc-email: Example config for using 'hg email' to contribute The initial setup can be tricky if you don't know what and were settings should be added. This should maybe also go into site/doc/contributing
author Kim Alvefur <zash@zash.se>
date Wed, 07 Jun 2023 16:56:53 +0200
parent 9993:02a41315d275
line wrap: on
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-- Mock util.time
local now = 0; -- wibbly-wobbly... timey-wimey... stuff
local function later(n)
	now = now + n; -- time passes at a different rate
end
package.loaded["util.time"] = {
	now = function() return now; end
}


local throttle = require "util.throttle";

describe("util.throttle", function()
	describe("#create()", function()
		it("should be created with correct values", function()
			now = 5;
			local a = throttle.create(3, 10);
			assert.same(a, { balance = 3, max = 3, rate = 0.3, t = 5 });

			local a = throttle.create(3, 5);
			assert.same(a, { balance = 3, max = 3, rate = 0.6, t = 5 });

			local a = throttle.create(1, 1);
			assert.same(a, { balance = 1, max = 1, rate = 1, t = 5 });

			local a = throttle.create(10, 10);
			assert.same(a, { balance = 10, max = 10, rate = 1, t = 5 });

			local a = throttle.create(10, 1);
			assert.same(a, { balance = 10, max = 10, rate = 10, t = 5 });
		end);
	end);

	describe("#update()", function()
		it("does nothing when no time has passed, even if balance is not full", function()
			now = 5;
			local a = throttle.create(10, 10);
			for i=1,5 do
				a:update();
				assert.same(a, { balance = 10, max = 10, rate = 1, t = 5 });
			end
			a.balance = 0;
			for i=1,5 do
				a:update();
				assert.same(a, { balance = 0, max = 10, rate = 1, t = 5 });
			end
		end);
		it("updates only time when time passes but balance is full", function()
			now = 5;
			local a = throttle.create(10, 10);
			for i=1,5 do
				later(5);
				a:update();
				assert.same(a, { balance = 10, max = 10, rate = 1, t = 5 + i*5 });
			end
		end);
		it("updates balance when balance has room to grow as time passes", function()
			now = 5;
			local a = throttle.create(10, 10);
			a.balance = 0;
			assert.same(a, { balance = 0, max = 10, rate = 1, t = 5 });

			later(1);
			a:update();
			assert.same(a, { balance = 1, max = 10, rate = 1, t = 6 });

			later(3);
			a:update();
			assert.same(a, { balance = 4, max = 10, rate = 1, t = 9 });

			later(10);
			a:update();
			assert.same(a, { balance = 10, max = 10, rate = 1, t = 19 });
		end);
		it("handles 10 x 0.1s updates the same as 1 x 1s update ", function()
			now = 5;
			local a = throttle.create(1, 1);

			a.balance = 0;
			later(1);
			a:update();
			assert.same(a, { balance = 1, max = 1, rate = 1, t = now });

			a.balance = 0;
			for i=1,10 do
				later(0.1);
				a:update();
			end
			assert(math.abs(a.balance - 1) < 0.0001); -- incremental updates cause rounding errors
		end);
	end);

	-- describe("po")

	describe("#poll()", function()
		it("should only allow successful polls until cost is hit", function()
			now = 5;

			local a = throttle.create(3, 10);
			assert.same(a, { balance = 3, max = 3, rate = 0.3, t = 5 });

			assert.is_true(a:poll(1));  -- 3 -> 2
			assert.same(a, { balance = 2, max = 3, rate = 0.3, t = 5 });

			assert.is_true(a:poll(2));  -- 2 -> 1
			assert.same(a, { balance = 0, max = 3, rate = 0.3, t = 5 });

			assert.is_false(a:poll(1)); -- MEEP, out of credits!
			assert.is_false(a:poll(1)); -- MEEP, out of credits!
			assert.same(a, { balance = 0, max = 3, rate = 0.3, t = 5 });
		end);

		it("should not allow polls more than the cost", function()
			now = 0;

			local a = throttle.create(10, 10);
			assert.same(a, { balance = 10, max = 10, rate = 1, t = 0 });

			assert.is_false(a:poll(11));
			assert.same(a, { balance = 10, max = 10, rate = 1, t = 0 });

			assert.is_true(a:poll(6));
			assert.same(a, { balance = 4, max = 10, rate = 1, t = 0 });

			assert.is_false(a:poll(5));
			assert.same(a, { balance = 4, max = 10, rate = 1, t = 0 });

			-- fractional
			assert.is_true(a:poll(3.5));
			assert.same(a, { balance = 0.5, max = 10, rate = 1, t = 0 });

			assert.is_true(a:poll(0.25));
			assert.same(a, { balance = 0.25, max = 10, rate = 1, t = 0 });

			assert.is_false(a:poll(0.3));
			assert.same(a, { balance = 0.25, max = 10, rate = 1, t = 0 });

			assert.is_true(a:poll(0.25));
			assert.same(a, { balance = 0, max = 10, rate = 1, t = 0 });

			assert.is_false(a:poll(0.1));
			assert.same(a, { balance = 0, max = 10, rate = 1, t = 0 });

			assert.is_true(a:poll(0));
			assert.same(a, { balance = 0, max = 10, rate = 1, t = 0 });
		end);
	end);
end);