pool: simplify inotify support in pool.

Motivation:

The pool will suppress sending read or write events if they are
happening too often.  This is injected as a setter; however, the value
isn't adjusted after a file is opened.

Modification:

Mark field-members 'final' and inject value with the constructor.

Result:

No user- or admin obserable changes.  Less code, so may be easier to
maintain.

Target: master
Requires-notes: no
Requires-book: no
Patch: https://rb.dcache.org/r/13056/
Acked-by: Lea Morschel

modules/dcache/src/main/java/org/dcache/pool/repository/inotify/InotifyChannel.java

@@ -71,29 +71,20 @@ private enum Operation {
     private final PnfsId target;
     private final boolean isOpenForRead;
     private final NotificationAmplifier notification;
+    private final Duration suppressDuration;
 
     private Operation lastOperation;
     private Instant whenSendNextEvent;
-    private Duration suppressDuration = Duration.ZERO;
 
 
     public InotifyChannel(RepositoryChannel inner, NotificationAmplifier notification,
-            PnfsId target, boolean openForWrite)
+            PnfsId target, boolean openForWrite, Duration suppressDuration)
     {
         this.inner = inner;
         this.target = target;
         isOpenForRead = !openForWrite;
         this.notification = notification;
-    }
-
-    public synchronized void setSuppressDuration(Duration duration)
-    {
-        Instant newWhenSendNextEvent = whenSendNextEvent == null
-                ? null
-                : whenSendNextEvent.minus(suppressDuration).plus(duration);
-
-        suppressDuration = duration;
-        whenSendNextEvent = newWhenSendNextEvent;
+        this.suppressDuration = suppressDuration;
     }
 
     @Override

modules/dcache/src/main/java/org/dcache/pool/repository/inotify/InotifyReplicaRecord.java

@@ -42,8 +42,7 @@ public class InotifyReplicaRecord extends ForwardingReplicaRecord
 {
     private final ReplicaRecord inner;
     private final NotificationAmplifier notification;
-
-    private Duration suppressDuration = Duration.ZERO;
+    private final Duration suppressDuration;
 
     public enum OpenFlags implements OpenOption
     {
@@ -58,19 +57,11 @@ public enum OpenFlags implements OpenOption
 
 
     public InotifyReplicaRecord(ReplicaRecord inner, NotificationAmplifier notification,
-            PnfsId target)
+            PnfsId target, Duration suppressDuration)
     {
         this.inner = inner;
         this.notification = notification;
-    }
-
-    /**
-     * Update the suppression period for all subsequently opened
-     * RepositoryChannel. Any already opened channels are not affected.
-     */
-    public void setSuppressDuration(Duration duration)
-    {
-        suppressDuration = duration;
+        this.suppressDuration = suppressDuration;
     }
 
     @Override
@@ -96,8 +87,7 @@ public RepositoryChannel openChannel(Set<? extends OpenOption> mode)
         boolean openForWrite = mode.contains(StandardOpenOption.WRITE);
 
         InotifyChannel channel = new InotifyChannel(innerChannel, notification,
-                getPnfsId(), openForWrite);
-        channel.setSuppressDuration(suppressDuration);
+                getPnfsId(), openForWrite, suppressDuration);
         channel.sendOpenEvent();
         return channel;
     }

modules/dcache/src/main/java/org/dcache/pool/repository/inotify/InotifyReplicaStore.java

@@ -63,9 +63,7 @@ public ReplicaRecord create(PnfsId id, Set<? extends OpenOption> flags)
             throws DuplicateEntryException, CacheException
     {
         ReplicaRecord innerRecord = super.create(id, flags);
-        InotifyReplicaRecord record = new InotifyReplicaRecord(innerRecord, notification, id);
-        record.setSuppressDuration(suppression);
-        return record;
+        return new InotifyReplicaRecord(innerRecord, notification, id, suppression);
     }
 
     @Override
@@ -76,8 +74,6 @@ public ReplicaRecord get(PnfsId id) throws CacheException
             return null;
         }
 
-        InotifyReplicaRecord record = new InotifyReplicaRecord(innerRecord, notification, id);
-        record.setSuppressDuration(suppression);
-        return record;
+        return new InotifyReplicaRecord(innerRecord, notification, id, suppression);
     }
 }