--- /dev/null
+/*******************************************************************************\r
+ * ============LICENSE_START==================================================\r
+ * * org.onap.dmaap\r
+ * * ===========================================================================\r
+ * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.\r
+ * * ===========================================================================\r
+ * * Licensed under the Apache License, Version 2.0 (the "License");\r
+ * * you may not use this file except in compliance with the License.\r
+ * * You may obtain a copy of the License at\r
+ * * \r
+ * * http://www.apache.org/licenses/LICENSE-2.0\r
+ * * \r
+ * * Unless required by applicable law or agreed to in writing, software\r
+ * * distributed under the License is distributed on an "AS IS" BASIS,\r
+ * * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+ * * See the License for the specific language governing permissions and\r
+ * * limitations under the License.\r
+ * * ============LICENSE_END====================================================\r
+ * *\r
+ * * ECOMP is a trademark and service mark of AT&T Intellectual Property.\r
+ * *\r
+ ******************************************************************************/\r
+\r
+\r
+package org.onap.dmaap.datarouter.node;\r
+\r
+import java.util.*;\r
+import java.io.*;\r
+\r
+/**\r
+ * Track redirections of subscriptions\r
+ */\r
+public class RedirManager {\r
+ private Hashtable<String, String> sid2primary = new Hashtable<String, String>();\r
+ private Hashtable<String, String> sid2secondary = new Hashtable<String, String>();\r
+ private String redirfile;\r
+ RateLimitedOperation op;\r
+ /**\r
+ * Create a mechanism for maintaining subscription redirections.\r
+ * @param redirfile The file to store the redirection information.\r
+ * @param mininterval The minimum number of milliseconds between writes to the redirection information file.\r
+ * @param timer The timer thread used to run delayed file writes.\r
+ */\r
+ public RedirManager(String redirfile, long mininterval, Timer timer) {\r
+ this.redirfile = redirfile;\r
+ op = new RateLimitedOperation(mininterval, timer) {\r
+ public void run() {\r
+ try {\r
+ StringBuffer sb = new StringBuffer();\r
+ for (String s: sid2primary.keySet()) {\r
+ sb.append(s).append(' ').append(sid2primary.get(s)).append(' ').append(sid2secondary.get(s)).append('\n');\r
+ }\r
+ OutputStream os = new FileOutputStream(RedirManager.this.redirfile);\r
+ os.write(sb.toString().getBytes());\r
+ os.close();\r
+ } catch (Exception e) {\r
+ }\r
+ }\r
+ };\r
+ try {\r
+ String s;\r
+ BufferedReader br = new BufferedReader(new FileReader(redirfile));\r
+ while ((s = br.readLine()) != null) {\r
+ s = s.trim();\r
+ String[] sx = s.split(" ");\r
+ if (s.startsWith("#") || sx.length != 3) {\r
+ continue;\r
+ }\r
+ sid2primary.put(sx[0], sx[1]);\r
+ sid2secondary.put(sx[0], sx[2]);\r
+ }\r
+ br.close();\r
+ } catch (Exception e) {\r
+ // missing file is normal\r
+ }\r
+ }\r
+ /**\r
+ * 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.\r
+ * @param sid The subscription ID to be redirected\r
+ * @param primary The URL associated with that subscription ID\r
+ * @param secondary The replacement URL to use instead\r
+ */\r
+ public synchronized void redirect(String sid, String primary, String secondary) {\r
+ sid2primary.put(sid, primary);\r
+ sid2secondary.put(sid, secondary);\r
+ op.request();\r
+ }\r
+ /**\r
+ * Cancel redirection. If a request is to be sent to subscription ID sid, send it to its primary URL.\r
+ * @param sid The subscription ID to remove from the table.\r
+ */\r
+ public synchronized void forget(String sid) {\r
+ sid2primary.remove(sid);\r
+ sid2secondary.remove(sid);\r
+ op.request();\r
+ }\r
+ /**\r
+ * 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.\r
+ * @param sid The subscription ID to look up.\r
+ * @param primary The configured primary URL.\r
+ * @return The destination URL to really use.\r
+ */\r
+ public synchronized String lookup(String sid, String primary) {\r
+ String oprim = sid2primary.get(sid);\r
+ if (primary.equals(oprim)) {\r
+ return(sid2secondary.get(sid));\r
+ } else if (oprim != null) {\r
+ forget(sid);\r
+ } \r
+ return(primary);\r
+ }\r
+ /**\r
+ * Is a subscription redirected?\r
+ */\r
+ public synchronized boolean isRedirected(String sid) {\r
+ return(sid != null && sid2secondary.get(sid) != null);\r
+ }\r
+}\r