1 files changed, 118 insertions, 0 deletions
diff --git a/datarouter-node/src/main/java/com/att/research/datarouter/node/RedirManager.java b/datarouter-node/src/main/java/com/att/research/datarouter/node/RedirManager.java
new file mode 100644
index 00000000..09473c14
--- /dev/null
+++ b/datarouter-node/src/main/java/com/att/research/datarouter/node/RedirManager.java
@@ -0,0 +1,118 @@
+/*******************************************************************************
+ * ============LICENSE_START==================================================
+ * * org.onap.dmaap
+ * * ===========================================================================
+ * * Copyright © 2017 AT&T Intellectual Property. 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.
+ * * ============LICENSE_END====================================================
+ * *
+ * * ECOMP is a trademark and service mark of AT&T Intellectual Property.
+ * *
+ ******************************************************************************/
+
+
+package com.att.research.datarouter.node;
+
+import java.util.*;
+import java.io.*;
+
+/**
+ *	Track redirections of subscriptions
+ */
+public class RedirManager	{
+	private Hashtable<String, String> sid2primary = new Hashtable<String, String>();
+	private Hashtable<String, String> sid2secondary = new Hashtable<String, String>();
+	private String	redirfile;
+	RateLimitedOperation	op;
+	/**
+	 *	Create a mechanism for maintaining subscription redirections.
+	 *	@param redirfile	The file to store the redirection information.
+	 *	@param mininterval	The minimum number of milliseconds between writes to the redirection information file.
+	 *	@param timer	The timer thread used to run delayed file writes.
+	 */
+	public RedirManager(String redirfile, long mininterval, Timer timer) {
+		this.redirfile = redirfile;
+		op = new RateLimitedOperation(mininterval, timer) {
+			public void run() {
+				try {
+					StringBuffer sb = new StringBuffer();
+					for (String s: sid2primary.keySet()) {
+						sb.append(s).append(' ').append(sid2primary.get(s)).append(' ').append(sid2secondary.get(s)).append('\n');
+					}
+					OutputStream os = new FileOutputStream(RedirManager.this.redirfile);
+					os.write(sb.toString().getBytes());
+					os.close();
+				} catch (Exception e) {
+				}
+			}
+		};
+		try {
+			String s;
+			BufferedReader br = new BufferedReader(new FileReader(redirfile));
+			while ((s = br.readLine()) != null) {
+				s = s.trim();
+				String[] sx = s.split(" ");
+				if (s.startsWith("#") || sx.length != 3) {
+					continue;
+				}
+				sid2primary.put(sx[0], sx[1]);
+				sid2secondary.put(sx[0], sx[2]);
+			}
+			br.close();
+		} catch (Exception e) {
+			// missing file is normal
+		}
+	}
+	/**
+	 *	Set up redirection.  If a request is to be sent to subscription ID sid, and that is configured to go to URL primary, instead, go to secondary.
+	 *	@param sid	The subscription ID to be redirected
+	 *	@param primary	The URL associated with that subscription ID
+	 *	@param secondary	The replacement URL to use instead
+	 */
+	public synchronized void redirect(String sid, String primary, String secondary) {
+		sid2primary.put(sid, primary);
+		sid2secondary.put(sid, secondary);
+		op.request();
+	}
+	/**
+	 *	Cancel redirection.  If a request is to be sent to subscription ID sid, send it to its primary URL.
+	 *	@param	sid	The subscription ID to remove from the table.
+	 */
+	public synchronized void forget(String sid) {
+		sid2primary.remove(sid);
+		sid2secondary.remove(sid);
+		op.request();
+	}
+	/**
+	 *	Look up where to send a subscription.  If the primary has changed or there is no redirection, use the primary.  Otherwise, redirect to the secondary URL.
+	 *	@param	sid	The subscription ID to look up.
+	 *	@param	primary	The configured primary URL.
+	 *	@return	The destination URL to really use.
+	 */
+	public synchronized String lookup(String sid, String primary) {
+		String oprim = sid2primary.get(sid);
+		if (primary.equals(oprim)) {
+			return(sid2secondary.get(sid));
+		} else if (oprim != null) {
+			forget(sid);
+		}	
+		return(primary);
+	}
+	/**
+	 *	Is a subscription redirected?
+	 */
+	public synchronized boolean isRedirected(String sid) {
+		return(sid != null && sid2secondary.get(sid) != null);
+	}
+}