clojure
diff --git a/‎src/main/clojure/clojure/core/cache.clj‎
Lines changed: 6 additions & 1 deletion b/‎src/main/clojure/clojure/core/cache.clj‎
Lines changed: 6 additions & 1 deletion
diff --git a/‎src/test/clojure/clojure/core/cache_test.clj‎
Lines changed: 19 additions & 1 deletion b/‎src/test/clojure/clojure/core/cache_test.clj‎
Lines changed: 19 additions & 1 deletion
@@ -39,6 +39,10 @@
    The contract is that said cache should return an instance of its
    own type."))
 
+(extend-protocol CacheProtocol
+  clojure.lang.IPersistentMap
+  (hit [this _] this))
+
 (def ^{:private true} default-wrapper-fn #(%1 %2))
 
 (defn through
@@ -281,7 +285,8 @@
                  t)
               ttl-ms))
          (contains? cache item)))
-  (hit [this item] this)
+  (hit [this item]
+    (TTLCacheQ. (hit cache item) ttl q gen ttl-ms))
   (miss [this item result]
     (let [now  (System/currentTimeMillis)
           [kill-old q'] (key-killer-q ttl q ttl-ms now)]
 
@@ -252,7 +252,15 @@
   (testing "TTL cache does not contain a value that was removed from underlying cache."
     (let [underlying-cache (lru-cache-factory {} :threshold 1)
           C (ttl-cache-factory underlying-cache :ttl 360000)]
-      (is (not (-> C (assoc :a 1) (assoc :b 2) (has? :a)))))))
+      (is (not (-> C (assoc :a 1) (assoc :b 2) (has? :a))))))
+  (testing "TTL cache propagates hits to the underlying cache's recency tracking."
+    (let [underlying-cache (lru-cache-factory {} :threshold 2)
+          C  (-> (ttl-cache-factory underlying-cache :ttl 360000)
+                 (assoc :a 1)
+                 (assoc :b 2))
+          C' (-> C (hit :a) (hit :a) (assoc :c 3))]
+      (is (has? C' :a)
+          ":a was hit twice and should not have been evicted in favor of :b"))))
 
 (deftest test-lu-cache-ilookup
   (testing "that the LUCache can lookup via keywords"
@@ -529,3 +537,13 @@ N non-resident HIR block
   (let [c (fifo-cache-factory {:a 1 :b 2} :threshold 2)]
     (is (= #{:a :c} (set (-> c (evict :b) (miss :c 42) (.q)))))
     (is (= #{:c :d} (set (-> c (evict :b) (miss :c 42) (miss :d 43) (.q)))))))
+
+(deftest propagation-to-composed-cache70
+  (testing "hits on a composed cache (TTL wrapping LRU) propagate to the wrapped cache's recency tracking"
+    (let [c-cache  (-> {:a 10 :b 20}
+                        (lru-cache-factory :threshold 3)
+                        (ttl-cache-factory :ttl 30000))
+          c-cache2 (miss c-cache :c 30)
+          c-cache3 (-> c-cache2 (hit :b) (hit :b) (hit :b))
+          c-cache4 (miss c-cache3 :d 40)]
+      (is (has? c-cache4 :b) ":b was hit 3 times and should not have been evicted in favor of :a or :c"))))