diff options
| -rw-r--r-- | tests/test_util_cache.lua | 89 | ||||
| -rw-r--r-- | util/cache.lua | 22 |
2 files changed, 96 insertions, 15 deletions
diff --git a/tests/test_util_cache.lua b/tests/test_util_cache.lua index 72cb5a85..78666edc 100644 --- a/tests/test_util_cache.lua +++ b/tests/test_util_cache.lua @@ -1,21 +1,44 @@ - function new(new) local c = new(5); + local function expect_kv(key, value, actual_key, actual_value) + assert_equal(key, actual_key, "key incorrect"); + assert_equal(value, actual_value, "value incorrect"); + end + + expect_kv(nil, nil, c:head()); + expect_kv(nil, nil, c:tail()); + assert_equal(c:count(), 0); c:set("one", 1) assert_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_equal(c:count(), 5); + expect_kv("five", 5, c:head()); + expect_kv("one", 1, c:tail()); c:set("foo", nil); assert_equal(c:count(), 5); + expect_kv("five", 5, c:head()); + expect_kv("one", 1, c:tail()); assert_equal(c:get("one"), 1); + expect_kv("five", 5, c:head()); + expect_kv("one", 1, c:tail()); + assert_equal(c:get("two"), 2); assert_equal(c:get("three"), 3); assert_equal(c:get("four"), 4); @@ -26,6 +49,8 @@ function new(new) c:set("six", 6); assert_equal(c:count(), 5); + expect_kv("six", 6, c:head()); + expect_kv("two", 2, c:tail()); assert_equal(c:get("one"), nil); assert_equal(c:get("two"), 2); @@ -197,22 +222,21 @@ function new(new) local c3 = new(1, function (_key, _value, c3) evicted_key, evicted_value = _key, _value; if _key == "a" then - -- Put it back in... - -- Check that the newest key/value was set before on_evict was called - assert_equal(c3:get("b"), 2); -- Sanity check for what we're evicting assert_equal(_key, "a"); assert_equal(_value, 1); - -- Re-insert the evicted key (causes this evict function to run again with "b",2) - c3:set(_key, _value) - assert_equal(c3:get(_key), _value) + -- 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; - c3:set(k, v); + local ret = c3:set(k, v); assert_equal(evicted_key, should_evict_key); assert_equal(evicted_value, should_evict_value); + return ret; end set("a", 1) set("a", 1) @@ -220,10 +244,55 @@ function new(new) set("a", 1) set("a", 1) - -- The evict handler re-inserts "a"->1, so "b" gets evicted: - set("b", 2, "b", 2) + -- Our on_evict prevents "a" from being evicted, causing this to fail... + assert_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_equal(c3:get("a"), 1); assert_equal(c3:get("b"), nil); assert_equal(c3:count(), 1); + + + local c4 = new(3, false); + + assert_equal(c4:set("a", 1), true); + assert_equal(c4:set("a", 1), true); + assert_equal(c4:set("a", 1), true); + assert_equal(c4:set("a", 1), true); + assert_equal(c4:set("b", 2), true); + assert_equal(c4:set("c", 3), true); + assert_equal(c4:set("d", 4), false); + assert_equal(c4:set("d", 4), false); + assert_equal(c4:set("d", 4), false); + + expect_kv("c", 3, c4:head()); + expect_kv("a", 1, c4:tail()); + + local c5 = new(3, function (k, v) + if k == "a" then + return nil; + elseif k == "b" then + return true; + end + return false; + end); + + assert_equal(c5:set("a", 1), true); + assert_equal(c5:set("a", 1), true); + assert_equal(c5:set("a", 1), true); + assert_equal(c5:set("a", 1), true); + assert_equal(c5:set("b", 2), true); + assert_equal(c5:set("c", 3), true); + assert_equal(c5:set("d", 4), true); -- "a" evicted (cb returned nil) + assert_equal(c5:set("d", 4), true); -- nop + assert_equal(c5:set("d", 4), true); -- nop + assert_equal(c5:set("e", 5), true); -- "b" evicted (cb returned true) + assert_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 diff --git a/util/cache.lua b/util/cache.lua index d3639b3f..074916cd 100644 --- a/util/cache.lua +++ b/util/cache.lua @@ -51,10 +51,13 @@ function cache_methods:set(k, v) return true; end -- Check whether we need to remove oldest k/v - local on_evict, evicted_key, evicted_value; if self._count == self.size then local tail = self._tail; - on_evict, evicted_key, evicted_value = self._on_evict, tail.key, tail.value; + local on_evict, evicted_key, evicted_value = self._on_evict, tail.key, tail.value; + if on_evict ~= nil and (on_evict == false or on_evict(evicted_key, evicted_value) == false) then + -- Cache is full, and we're not allowed to evict + return false; + end _remove(self, tail); self._data[evicted_key] = nil; end @@ -62,9 +65,6 @@ function cache_methods:set(k, v) m = { key = k, value = v, prev = nil, next = nil }; self._data[k] = m; _insert(self, m); - if on_evict and evicted_key then - on_evict(evicted_key, evicted_value, self); - end return true; end @@ -92,6 +92,18 @@ function cache_methods:count() return self._count; end +function cache_methods:head() + local head = self._head; + if not head then return nil, nil; end + return head.key, head.value; +end + +function cache_methods:tail() + local tail = self._tail; + if not tail then return nil, nil; end + return tail.key, tail.value; +end + local function new(size, on_evict) size = assert(tonumber(size), "cache size must be a number"); size = math.floor(size); |