[DMAAP-48] Initial code import

[dmaap/datarouter.git] / datarouter-node / src / main / java / com / att / research / datarouter / node / RedirManager.java

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 (file)
index 0000000..09473c1
--- /dev/null
+++ b/datarouter-node/src/main/java/com/att/research/datarouter/node/RedirManager.java
@@ -0,0 +1,118 @@
+/*******************************************************************************\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 com.att.research.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