GO-2076 Add TryRemove method to Ocache

app/ocache/ocache.go

@@ -89,6 +89,8 @@ type OCache interface {
 	Add(id string, value Object) (err error)
 	// Remove closes and removes object
 	Remove(ctx context.Context, id string) (ok bool, err error)
+	// TryRemove Tries to close and to remove the object
+	TryRemove(id string) (ok bool, err error)
 	// ForEach iterates over all loaded objects, breaks when callback returns false
 	ForEach(f func(v Object) (isContinue bool))
 	// GC frees not used and expired objects
@@ -212,6 +214,45 @@ func (c *oCache) remove(ctx context.Context, e *entry) (ok bool, err error) {
 	return
 }
 
+func (c *oCache) TryRemove(id string) (ok bool, err error) {
+	c.mu.Lock()
+
+	if c.closed {
+		c.mu.Unlock()
+		return false, ErrClosed
+	}
+
+	e, contains := c.data[id]
+	if !contains {
+		c.mu.Unlock()
+		return false, ErrNotExists
+	}
+
+	c.mu.Unlock()
+
+	prevState, _ := e.setClosing(false)
+	if prevState == entryStateClosing || prevState == entryStateClosed {
+		return false, nil
+	}
+
+	closed, err := e.value.TryClose(c.ttl)
+	if err != nil {
+		c.log.With("object_id", e.id).Warnf("try remove err: %v", err)
+		return closed, err
+	}
+
+	if !closed {
+		e.setActive(true)
+		return false, nil
+	}
+
+	c.mu.Lock()
+	e.setClosed()
+	delete(c.data, e.id)
+	c.mu.Unlock()
+	return true, nil
+}
+
 func (c *oCache) DoLockedIfNotExists(id string, action func() error) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()

app/ocache/ocache_test.go

@@ -317,6 +317,78 @@ func Test_OCache_Remove(t *testing.T) {
 		<-getCh
 		require.Equal(t, []string{"close", "get"}, events)
 	})
+	t.Run("tryRemove simple", func(t *testing.T) {
+		closeCh := make(chan struct{})
+		getCh := make(chan struct{})
+		c := New(func(ctx context.Context, id string) (value Object, err error) {
+			return NewTestObject(id, true, closeCh), nil
+		}, WithTTL(time.Millisecond*10))
+
+		val, err := c.Get(context.TODO(), "id")
+		require.NoError(t, err)
+		require.NotNil(t, val)
+		assert.Equal(t, 1, c.Len())
+		// try removing the object, so we will wait on closing
+		go func() {
+			_, err := c.TryRemove("id")
+			require.Equal(t, 0, c.Len())
+			require.NoError(t, err)
+		}()
+		time.Sleep(time.Millisecond * 20)
+
+		var events []string
+		go func() {
+			_, err := c.Get(context.TODO(), "id")
+			require.Equal(t, 1, c.Len())
+			require.NoError(t, err)
+			require.NotNil(t, val)
+			events = append(events, "get")
+			close(getCh)
+		}()
+		// sleeping to make sure that Get is called
+		time.Sleep(time.Millisecond * 20)
+		events = append(events, "close")
+		close(closeCh)
+
+		<-getCh
+		require.Equal(t, []string{"close", "get"}, events)
+	})
+	t.Run("tryRemove simple - can't be removed", func(t *testing.T) {
+		closeCh := make(chan struct{})
+		getCh := make(chan struct{})
+		c := New(func(ctx context.Context, id string) (value Object, err error) {
+			return NewTestObject(id, false, closeCh), nil
+		}, WithTTL(time.Millisecond*10))
+
+		val, err := c.Get(context.TODO(), "id")
+		require.NoError(t, err)
+		require.NotNil(t, val)
+		assert.Equal(t, 1, c.Len())
+		// try removing the object, so we will wait on closing
+		go func() {
+			_, err := c.TryRemove("id")
+			require.Equal(t, 1, c.Len())
+			require.NoError(t, err)
+		}()
+		time.Sleep(time.Millisecond * 20)
+
+		var events []string
+		go func() {
+			_, err := c.Get(context.TODO(), "id")
+			require.Equal(t, 1, c.Len())
+			require.NoError(t, err)
+			require.NotNil(t, val)
+			events = append(events, "get")
+			close(getCh)
+		}()
+		// sleeping to make sure that Get is called
+		time.Sleep(time.Millisecond * 20)
+		events = append(events, "close")
+		close(closeCh)
+
+		<-getCh
+		require.Equal(t, []string{"close", "get"}, events)
+	})
 	t.Run("test remove while gc, tryClose false", func(t *testing.T) {
 		closeCh := make(chan struct{})
 		removeCh := make(chan struct{})