Move protocol framework from BGPCEP project

[controller.git] / opendaylight / commons / protocol-framework / src / main / java / org / opendaylight / protocol / framework / ReconnectStrategy.java

diff --git a/opendaylight/commons/protocol-framework/src/main/java/org/opendaylight/protocol/framework/ReconnectStrategy.java b/opendaylight/commons/protocol-framework/src/main/java/org/opendaylight/protocol/framework/ReconnectStrategy.java
new file mode 100644 (file)
index 0000000..24ff84b
--- /dev/null
+++ b/opendaylight/commons/protocol-framework/src/main/java/org/opendaylight/protocol/framework/ReconnectStrategy.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2013 Cisco Systems, Inc. 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.protocol.framework;
+
+import io.netty.util.concurrent.Future;
+
+/**
+ * Interface exposed by a reconnection strategy provider. A reconnection
+ * strategy decides whether to attempt reconnection and when to do that.
+ *
+ * The proper way of using this API is such that when a connection attempt
+ * has failed, the user will call scheduleReconnect() to obtain a future,
+ * which tracks schedule of the next connect attempt. The user should add its
+ * own listener to be get notified when the future is done. Once the
+ * the notification fires, user should examine the future to see whether
+ * it is successful or not. If it is successful, the user should immediately
+ * initiate a connection attempt. If it is unsuccessful, the user must
+ * not attempt any more connection attempts and should abort the reconnection
+ * process.
+ */
+public interface ReconnectStrategy {
+    /**
+     * Query the strategy for the connect timeout.
+     *
+     * @return connect try timeout in milliseconds, or
+     *         0 for infinite (or system-default) timeout
+     * @throws Exception if the connection should not be attempted
+     */
+    int getConnectTimeout() throws Exception;
+
+    /**
+     * Schedule a connection attempt. The precise time when the connection
+     * should be attempted is signaled by successful completion of returned
+     * future.
+     *
+     * @param cause Cause of previous failure
+     * @return a future tracking the schedule, may not be null
+     * @throws IllegalStateException when a connection attempt is currently
+     *         scheduled.
+     */
+    Future<Void> scheduleReconnect(Throwable cause);
+
+    /**
+     * Reset the strategy state. Users call this method once the reconnection
+     * process succeeds.
+     */
+    void reconnectSuccessful();
+}