opendaylight/md-sal/sal-rest-connector/src/main/java/org/opendaylight/controller/sal/streams/listeners/Notificator.java

   1 package org.opendaylight.controller.sal.streams.listeners;
   2
   3 import java.util.Map;
   4 import java.util.concurrent.ConcurrentHashMap;
   5 import java.util.concurrent.locks.Lock;
   6 import java.util.concurrent.locks.ReentrantLock;
   7
   8 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
   9
  10 public class Notificator {
  11
  12     private static Map<String, ListenerAdapter> listenersByStreamName = new ConcurrentHashMap<>();
  13     private static Map<InstanceIdentifier, ListenerAdapter> listenersByInstanceIdentifier = new ConcurrentHashMap<>();
  14     private static final Lock lock = new ReentrantLock();
  15
  16     private Notificator() {
  17     }
  18
  19     public static ListenerAdapter getListenerFor(String streamName) {
  20         return listenersByStreamName.get(streamName);
  21     }
  22
  23     public static ListenerAdapter getListenerFor(InstanceIdentifier path) {
  24         return listenersByInstanceIdentifier.get(path);
  25     }
  26
  27     public static boolean existListenerFor(InstanceIdentifier path) {
  28         return listenersByInstanceIdentifier.containsKey(path);
  29     }
  30
  31     public static ListenerAdapter createListener(InstanceIdentifier path, String streamName) {
  32         ListenerAdapter listener = new ListenerAdapter(path, streamName);
  33         try {
  34             lock.lock();
  35             listenersByInstanceIdentifier.put(path, listener);
  36             listenersByStreamName.put(streamName, listener);
  37         } finally {
  38             lock.unlock();
  39         }
  40         return listener;
  41     }
  42
  43     public static void removeListener(InstanceIdentifier path) {
  44         ListenerAdapter listener = listenersByInstanceIdentifier.get(path);
  45         deleteListener(listener);
  46     }
  47
  48     public static String createStreamNameFromUri(String uri) {
  49         if (uri == null) {
  50             return null;
  51         }
  52         String result = uri;
  53         if (result.startsWith("/")) {
  54             result = result.substring(1);
  55         }
  56         if (result.endsWith("/")) {
  57             result = result.substring(0, result.length());
  58         }
  59         return result;
  60     }
  61
  62     public static void removeAllListeners() {
  63         for (ListenerAdapter listener : listenersByInstanceIdentifier.values()) {
  64             try {
  65                 listener.close();
  66             } catch (Exception e) {
  67             }
  68         }
  69         try {
  70             lock.lock();
  71             listenersByStreamName = new ConcurrentHashMap<>();
  72             listenersByInstanceIdentifier = new ConcurrentHashMap<>();
  73         } finally {
  74             lock.unlock();
  75         }
  76     }
  77
  78     public static void removeListenerIfNoSubscriberExists(ListenerAdapter listener) {
  79         if (!listener.hasSubscribers()) {
  80             deleteListener(listener);
  81         }
  82     }
  83
  84     private static void deleteListener(ListenerAdapter listener) {
  85         if (listener != null) {
  86             try {
  87                 listener.close();
  88             } catch (Exception e) {
  89             }
  90             try {
  91                 lock.lock();
  92                 listenersByInstanceIdentifier.remove(listener.getPath());
  93                 listenersByStreamName.remove(listener.getStreamName());
  94             } finally {
  95                 lock.unlock();
  96             }
  97         }
  98     }
  99
 100 }