Rework ClusterSingletonServiceGroupImpl locking

[mdsal.git] / singleton-service / mdsal-singleton-dom-impl / src / main / java / org / opendaylight / mdsal / singleton / dom / impl / ServiceInfo.java

diff --git a/singleton-service/mdsal-singleton-dom-impl/src/main/java/org/opendaylight/mdsal/singleton/dom/impl/ServiceInfo.java b/singleton-service/mdsal-singleton-dom-impl/src/main/java/org/opendaylight/mdsal/singleton/dom/impl/ServiceInfo.java
new file mode 100644 (file)
index 0000000..f864976
--- /dev/null
+++ b/singleton-service/mdsal-singleton-dom-impl/src/main/java/org/opendaylight/mdsal/singleton/dom/impl/ServiceInfo.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2018 Pantheon Technologies, s.r.o. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.mdsal.singleton.dom.impl;
+
+import static com.google.common.base.Verify.verify;
+import static com.google.common.base.Verify.verifyNotNull;
+import static java.util.Objects.requireNonNull;
+
+import com.google.common.util.concurrent.ListenableFuture;
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
+import org.opendaylight.mdsal.singleton.dom.impl.ClusterSingletonServiceGroupImpl.ServiceState;
+
+@NonNullByDefault
+final class ServiceInfo {
+    private static final ServiceInfo STARTED = new ServiceInfo(ServiceState.STARTED, null);
+
+    private final @Nullable ListenableFuture<?> future;
+    private final ServiceState state;
+
+    private ServiceInfo(final ServiceState state, final @Nullable ListenableFuture<?> future) {
+        this.state = requireNonNull(state);
+        this.future = future;
+    }
+
+    static ServiceInfo started() {
+        return STARTED;
+    }
+
+    ServiceState getState() {
+        return state;
+    }
+
+    ListenableFuture<?> getFuture() {
+        return verifyNotNull(future);
+    }
+
+    ServiceInfo toState(final ServiceState newState) {
+        verify(state != newState, "Attempted to re-transition into %s", state);
+        return new ServiceInfo(newState, null);
+    }
+
+    ServiceInfo toState(final ServiceState newState, final ListenableFuture<?> newFuture) {
+        verify(state != newState, "Attempted to re-transition into %s", state);
+        return new ServiceInfo(newState, requireNonNull(newFuture));
+    }
+}