[ONOS-6497] Add globally unique numeric ID generator primitive
Change-Id: Ic2d9214cfa885344694b8ba4250054dd6a33144e
diff --git a/core/api/src/main/java/org/onosproject/store/primitives/DefaultAtomicIdGenerator.java b/core/api/src/main/java/org/onosproject/store/primitives/DefaultAtomicIdGenerator.java
new file mode 100644
index 0000000..97cc45f
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/store/primitives/DefaultAtomicIdGenerator.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2017-present Open Networking Laboratory
+ *
+ * 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.onosproject.store.primitives;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+import org.onosproject.store.service.AsyncAtomicIdGenerator;
+import org.onosproject.store.service.AtomicIdGenerator;
+import org.onosproject.store.service.StorageException;
+import org.onosproject.store.service.Synchronous;
+
+/**
+ * Default implementation for a {@code AtomicIdGenerator} backed by a {@link AsyncAtomicIdGenerator}.
+ */
+public class DefaultAtomicIdGenerator extends Synchronous<AsyncAtomicIdGenerator> implements AtomicIdGenerator {
+
+ private final AsyncAtomicIdGenerator asyncIdGenerator;
+ private final long operationTimeoutMillis;
+
+ public DefaultAtomicIdGenerator(AsyncAtomicIdGenerator asyncIdGenerator, long operationTimeoutMillis) {
+ super(asyncIdGenerator);
+ this.asyncIdGenerator = asyncIdGenerator;
+ this.operationTimeoutMillis = operationTimeoutMillis;
+ }
+
+ @Override
+ public long nextId() {
+ return complete(asyncIdGenerator.nextId());
+ }
+
+ private <T> T complete(CompletableFuture<T> future) {
+ try {
+ return future.get(operationTimeoutMillis, TimeUnit.MILLISECONDS);
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ throw new StorageException.Interrupted();
+ } catch (TimeoutException e) {
+ throw new StorageException.Timeout();
+ } catch (ExecutionException e) {
+ throw new StorageException(e.getCause());
+ }
+ }
+}