1 files changed, 49 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/session/cache/CacheValue.java b/src/main/java/org/traccar/session/cache/CacheValue.java
new file mode 100644
index 000000000..9e955dfe5
--- /dev/null
+++ b/src/main/java/org/traccar/session/cache/CacheValue.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2022 Anton Tananaev (anton@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.session.cache;
+
+import org.traccar.model.BaseModel;
+
+import java.util.HashSet;
+import java.util.Set;
+
+class CacheValue {
+
+    private final BaseModel value;
+    private final Set<Long> references = new HashSet<>();
+
+    CacheValue(BaseModel value) {
+        this.value = value;
+    }
+
+    public void retain(long deviceId) {
+        references.add(deviceId);
+    }
+
+    public void release(long deviceId) {
+        references.remove(deviceId);
+    }
+
+    @SuppressWarnings("unchecked")
+    public <T extends BaseModel> T getValue() {
+        return (T) value;
+    }
+
+    public Set<Long> getReferences() {
+        return references;
+    }
+
+}