prosody/spec/util_cache_spec.lua

local cache = require "util.cache";

describe("util.cache", function()
	describe("#new()", function()
		it("should work", function()

			local c = cache.new(5);

			local function expect_kv(key, value, actual_key, actual_value)
				assert.are.equal(key, actual_key, "key incorrect");
				assert.are.equal(value, actual_value, "value incorrect");
			end

			expect_kv(nil, nil, c:head());
			expect_kv(nil, nil, c:tail());

			assert.are.equal(c:count(), 0);

			c:set("one", 1)
			assert.are.equal(c:count(), 1);
			expect_kv("one", 1, c:head());
			expect_kv("one", 1, c:tail());

			c:set("two", 2)
			expect_kv("two", 2, c:head());
			expect_kv("one", 1, c:tail());

			c:set("three", 3)
			expect_kv("three", 3, c:head());
			expect_kv("one", 1, c:tail());

			c:set("four", 4)
			c:set("five", 5);
			assert.are.equal(c:count(), 5);
			expect_kv("five", 5, c:head());
			expect_kv("one", 1, c:tail());

			c:set("foo", nil);
			assert.are.equal(c:count(), 5);
			expect_kv("five", 5, c:head());
			expect_kv("one", 1, c:tail());

			assert.are.equal(c:get("one"), 1);
			expect_kv("five", 5, c:head());
			expect_kv("one", 1, c:tail());

			assert.are.equal(c:get("two"), 2);
			assert.are.equal(c:get("three"), 3);
			assert.are.equal(c:get("four"), 4);
			assert.are.equal(c:get("five"), 5);

			assert.are.equal(c:get("foo"), nil);
			assert.are.equal(c:get("bar"), nil);

			c:set("six", 6);
			assert.are.equal(c:count(), 5);
			expect_kv("six", 6, c:head());
			expect_kv("two", 2, c:tail());

			assert.are.equal(c:get("one"), nil);
			assert.are.equal(c:get("two"), 2);
			assert.are.equal(c:get("three"), 3);
			assert.are.equal(c:get("four"), 4);
			assert.are.equal(c:get("five"), 5);
			assert.are.equal(c:get("six"), 6);

			c:set("three", nil);
			assert.are.equal(c:count(), 4);

			assert.are.equal(c:get("one"), nil);
			assert.are.equal(c:get("two"), 2);
			assert.are.equal(c:get("three"), nil);
			assert.are.equal(c:get("four"), 4);
			assert.are.equal(c:get("five"), 5);
			assert.are.equal(c:get("six"), 6);

			c:set("seven", 7);
			assert.are.equal(c:count(), 5);

			assert.are.equal(c:get("one"), nil);
			assert.are.equal(c:get("two"), 2);
			assert.are.equal(c:get("three"), nil);
			assert.are.equal(c:get("four"), 4);
			assert.are.equal(c:get("five"), 5);
			assert.are.equal(c:get("six"), 6);
			assert.are.equal(c:get("seven"), 7);

			c:set("eight", 8);
			assert.are.equal(c:count(), 5);

			assert.are.equal(c:get("one"), nil);
			assert.are.equal(c:get("two"), nil);
			assert.are.equal(c:get("three"), nil);
			assert.are.equal(c:get("four"), 4);
			assert.are.equal(c:get("five"), 5);
			assert.are.equal(c:get("six"), 6);
			assert.are.equal(c:get("seven"), 7);
			assert.are.equal(c:get("eight"), 8);

			c:set("four", 4);
			assert.are.equal(c:count(), 5);

			assert.are.equal(c:get("one"), nil);
			assert.are.equal(c:get("two"), nil);
			assert.are.equal(c:get("three"), nil);
			assert.are.equal(c:get("four"), 4);
			assert.are.equal(c:get("five"), 5);
			assert.are.equal(c:get("six"), 6);
			assert.are.equal(c:get("seven"), 7);
			assert.are.equal(c:get("eight"), 8);

			c:set("nine", 9);
			assert.are.equal(c:count(), 5);

			assert.are.equal(c:get("one"), nil);
			assert.are.equal(c:get("two"), nil);
			assert.are.equal(c:get("three"), nil);
			assert.are.equal(c:get("four"), 4);
			assert.are.equal(c:get("five"), nil);
			assert.are.equal(c:get("six"), 6);
			assert.are.equal(c:get("seven"), 7);
			assert.are.equal(c:get("eight"), 8);
			assert.are.equal(c:get("nine"), 9);

			do
				local keys = { "nine", "four", "eight", "seven", "six" };
				local values = { 9, 4, 8, 7, 6 };
				local i = 0;
				for k, v in c:items() do
					i = i + 1;
					assert.are.equal(k, keys[i]);
					assert.are.equal(v, values[i]);
				end
				assert.are.equal(i, 5);

				c:set("four", "2+2");
				assert.are.equal(c:count(), 5);

				assert.are.equal(c:get("one"), nil);
				assert.are.equal(c:get("two"), nil);
				assert.are.equal(c:get("three"), nil);
				assert.are.equal(c:get("four"), "2+2");
				assert.are.equal(c:get("five"), nil);
				assert.are.equal(c:get("six"), 6);
				assert.are.equal(c:get("seven"), 7);
				assert.are.equal(c:get("eight"), 8);
				assert.are.equal(c:get("nine"), 9);
			end

			do
				local keys = { "four", "nine", "eight", "seven", "six" };
				local values = { "2+2", 9, 8, 7, 6 };
				local i = 0;
				for k, v in c:items() do
					i = i + 1;
					assert.are.equal(k, keys[i]);
					assert.are.equal(v, values[i]);
				end
				assert.are.equal(i, 5);

				c:set("foo", nil);
				assert.are.equal(c:count(), 5);

				assert.are.equal(c:get("one"), nil);
				assert.are.equal(c:get("two"), nil);
				assert.are.equal(c:get("three"), nil);
				assert.are.equal(c:get("four"), "2+2");
				assert.are.equal(c:get("five"), nil);
				assert.are.equal(c:get("six"), 6);
				assert.are.equal(c:get("seven"), 7);
				assert.are.equal(c:get("eight"), 8);
				assert.are.equal(c:get("nine"), 9);
			end

			do
				local keys = { "four", "nine", "eight", "seven", "six" };
				local values = { "2+2", 9, 8, 7, 6 };
				local i = 0;
				for k, v in c:items() do
					i = i + 1;
					assert.are.equal(k, keys[i]);
					assert.are.equal(v, values[i]);
				end
				assert.are.equal(i, 5);

				c:set("four", nil);

				assert.are.equal(c:get("one"), nil);
				assert.are.equal(c:get("two"), nil);
				assert.are.equal(c:get("three"), nil);
				assert.are.equal(c:get("four"), nil);
				assert.are.equal(c:get("five"), nil);
				assert.are.equal(c:get("six"), 6);
				assert.are.equal(c:get("seven"), 7);
				assert.are.equal(c:get("eight"), 8);
				assert.are.equal(c:get("nine"), 9);
			end

			do
				local keys = { "nine", "eight", "seven", "six" };
				local values = { 9, 8, 7, 6 };
				local i = 0;
				for k, v in c:items() do
					i = i + 1;
					assert.are.equal(k, keys[i]);
					assert.are.equal(v, values[i]);
				end
				assert.are.equal(i, 4);
			end

			do
				local evicted_key, evicted_value;
				local c2 = cache.new(3, function (_key, _value)
					evicted_key, evicted_value = _key, _value;
				end);
				local function set(k, v, should_evict_key, should_evict_value)
					evicted_key, evicted_value = nil, nil;
					c2:set(k, v);
					assert.are.equal(evicted_key, should_evict_key);
					assert.are.equal(evicted_value, should_evict_value);
				end
				set("a", 1)
				set("a", 1)
				set("a", 1)
				set("a", 1)
				set("a", 1)

				set("b", 2)
				set("c", 3)
				set("b", 2)
				set("d", 4, "a", 1)
				set("e", 5, "c", 3)
			end

			do
				local evicted_key, evicted_value;
				local c3 = cache.new(1, function (_key, _value)
					evicted_key, evicted_value = _key, _value;
					if _key == "a" then
						-- Sanity check for what we're evicting
						assert.are.equal(_key, "a");
						assert.are.equal(_value, 1);
						-- We're going to block eviction of this key/value, so set to nil...
						evicted_key, evicted_value = nil, nil;
						-- Returning false to block eviction
						return false
					end
				end);
				local function set(k, v, should_evict_key, should_evict_value)
					evicted_key, evicted_value = nil, nil;
					local ret = c3:set(k, v);
					assert.are.equal(evicted_key, should_evict_key);
					assert.are.equal(evicted_value, should_evict_value);
					return ret;
				end
				set("a", 1)
				set("a", 1)
				set("a", 1)
				set("a", 1)
				set("a", 1)

				-- Our on_evict prevents "a" from being evicted, causing this to fail...
				assert.are.equal(set("b", 2), false, "Failed to prevent eviction, or signal result");

				expect_kv("a", 1, c3:head());
				expect_kv("a", 1, c3:tail());

				-- Check the final state is what we expect
				assert.are.equal(c3:get("a"), 1);
				assert.are.equal(c3:get("b"), nil);
				assert.are.equal(c3:count(), 1);
			end


			local c4 = cache.new(3, false);

			assert.are.equal(c4:set("a", 1), true);
			assert.are.equal(c4:set("a", 1), true);
			assert.are.equal(c4:set("a", 1), true);
			assert.are.equal(c4:set("a", 1), true);
			assert.are.equal(c4:set("b", 2), true);
			assert.are.equal(c4:set("c", 3), true);
			assert.are.equal(c4:set("d", 4), false);
			assert.are.equal(c4:set("d", 4), false);
			assert.are.equal(c4:set("d", 4), false);

			expect_kv("c", 3, c4:head());
			expect_kv("a", 1, c4:tail());

			local c5 = cache.new(3, function (k, v) --luacheck: ignore 212/v
				if k == "a" then
					return nil;
				elseif k == "b" then
					return true;
				end
				return false;
			end);

			assert.are.equal(c5:set("a", 1), true);
			assert.are.equal(c5:set("a", 1), true);
			assert.are.equal(c5:set("a", 1), true);
			assert.are.equal(c5:set("a", 1), true);
			assert.are.equal(c5:set("b", 2), true);
			assert.are.equal(c5:set("c", 3), true);
			assert.are.equal(c5:set("d", 4), true); -- "a" evicted (cb returned nil)
			assert.are.equal(c5:set("d", 4), true); -- nop
			assert.are.equal(c5:set("d", 4), true); -- nop
			assert.are.equal(c5:set("e", 5), true); -- "b" evicted (cb returned true)
			assert.are.equal(c5:set("f", 6), false); -- "c" won't evict (cb returned false)

			expect_kv("e", 5, c5:head());
			expect_kv("c", 3, c5:tail());
		end);
	end);
end);