Diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spec/util_cache_spec.lua	Fri Sep 15 17:07:57 2017 -0400
@@ -0,0 +1,316 @@
+
+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)
+				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);