1 files changed, 76 insertions, 0 deletions
diff --git a/bundles/org.eclipse.equinox.logstream/src/org/osgi/util/pushstream/QueuePolicyOption.java b/bundles/org.eclipse.equinox.logstream/src/org/osgi/util/pushstream/QueuePolicyOption.java
new file mode 100644
index 000000000..35df890ee
--- /dev/null
+++ b/bundles/org.eclipse.equinox.logstream/src/org/osgi/util/pushstream/QueuePolicyOption.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) OSGi Alliance (2015, 2016). All Rights Reserved.
+ * 
+ * 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.osgi.util.pushstream;
+
+import java.util.concurrent.BlockingQueue;
+
+/**
+ * {@link QueuePolicyOption} provides a standard set of simple
+ * {@link QueuePolicy} implementations.
+ * 
+ * @see QueuePolicy
+ */
+public enum QueuePolicyOption {
+	/**
+	 * Attempt to add the supplied event to the queue. If the queue is unable to
+	 * immediately accept the value then discard the value at the head of the
+	 * queue and try again. Repeat this process until the event is enqueued.
+	 */
+	DISCARD_OLDEST {
+		@Override
+		public <T, U extends BlockingQueue<PushEvent<? extends T>>> QueuePolicy<T, U> getPolicy() {
+			return (queue, event) -> {
+				while (!queue.offer(event)) {
+					queue.poll();
+				}
+			};
+		}
+	},
+	/**
+	 * Attempt to add the supplied event to the queue, blocking until the
+	 * enqueue is successful.
+	 */
+	BLOCK {
+		@Override
+		public <T, U extends BlockingQueue<PushEvent<? extends T>>> QueuePolicy<T, U> getPolicy() {
+			return (queue, event) -> {
+				try {
+					queue.put(event);
+				} catch (InterruptedException e) {
+					// TODO Auto-generated catch block
+					e.printStackTrace();
+				}
+			};
+		}
+	},
+	/**
+	 * Attempt to add the supplied event to the queue, throwing an exception if
+	 * the queue is full.
+	 */
+	FAIL {
+		@Override
+		public <T, U extends BlockingQueue<PushEvent<? extends T>>> QueuePolicy<T, U> getPolicy() {
+			return (queue, event) -> queue.add(event);
+		}
+	};
+
+	/**
+	 * @return a {@link QueuePolicy} implementation
+	 */
+	public abstract <T, U extends BlockingQueue<PushEvent<? extends T>>> QueuePolicy<T, U> getPolicy();
+
+}