bugfix: cache get function, when in pin mode, should not increase the…

… counter before expiration check (cadence-workflow#665)

common/cache/lru.go

@@ -167,16 +167,15 @@ func (c *lru) Get(key interface{}) interface{} {
 
 	entry := element.Value.(*entryImpl)
 
-	if c.pin {
-		entry.refCount++
-	}
-
 	if c.isEntryExpired(entry, time.Now()) {
 		// Entry has expired
 		c.deleteInternal(element)
 		return nil
 	}
 
+	if c.pin {
+		entry.refCount++
+	}
 	c.byAccess.MoveToFront(element)
 	return entry.value
 }

common/cache/lru_test.go

@@ -200,6 +200,37 @@ func TestRemovedFuncWithTTL(t *testing.T) {
 	}
 }
 
+func TestRemovedFuncWithTTL_Pin(t *testing.T) {
+	ch := make(chan bool)
+	cache := New(5, &Options{
+		TTL: time.Millisecond * 50,
+		Pin: true,
+		RemovedFunc: func(i interface{}) {
+			_, ok := i.(*testing.T)
+			assert.True(t, ok)
+			ch <- true
+		},
+	})
+
+	cache.PutIfNotExist("A", t)
+	assert.Equal(t, t, cache.Get("A"))
+	time.Sleep(time.Millisecond * 100)
+	assert.Equal(t, t, cache.Get("A"))
+	// release 3 time since put if not exist also increase the counter
+	cache.Release("A")
+	cache.Release("A")
+	cache.Release("A")
+	assert.Nil(t, cache.Get("A"))
+
+	timeout := time.NewTimer(time.Millisecond * 300)
+	select {
+	case b := <-ch:
+		assert.True(t, b)
+	case <-timeout.C:
+		t.Error("RemovedFunc did not send true on channel ch")
+	}
+}
+
 func TestIterator(t *testing.T) {
 	expected := map[string]string{
 		"A": "Alpha",