Merge pull request #90 from iterate-ch/bugfix/issue-37

Extract interface for client cache to allow custom implementations. S…

core/src/main/java/org/dcache/nfs/v4/ClientCache.java

+/*
+ * Copyright (c) 2020 iterate GmbH
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this program (see the file COPYING.LIB for more
+ * details); if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+package org.dcache.nfs.v4;
+
+import org.dcache.nfs.v4.xdr.clientid4;
+
+import java.util.stream.Stream;
+
+public interface ClientCache {
+
+    /**
+     * Cache client by id
+     *
+     * @param clientid4  Client id
+     * @param nfs4Client Client reference
+     */
+    void put(clientid4 clientid4, NFS4Client nfs4Client);
+
+    /**
+     * @param clientid4 Client id
+     * @return Cached client or null if not found
+     */
+    NFS4Client get(clientid4 clientid4);
+
+    /**
+     * Remove client by id
+     *
+     * @param clientid4 Client id
+     * @return Previously cached client if any
+     */
+    NFS4Client remove(clientid4 clientid4);
+
+    /**
+     * Check and remove expired entries.
+     */
+    void cleanUp();
+
+    /**
+     * @return Return cached clients and update last access time for elements retrieved.
+     */
+    Stream<NFS4Client> stream();
+
+    /**
+     * @return Return cached clients. The last access time of the element will not be updated.
+     */
+    Stream<NFS4Client> peek();
+}

core/src/main/java/org/dcache/nfs/v4/DefaultClientCache.java

+/*
+ * Copyright (c) 2020 iterate GmbH
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this program (see the file COPYING.LIB for more
+ * details); if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+package org.dcache.nfs.v4;
+
+import org.dcache.nfs.util.Cache;
+import org.dcache.nfs.util.CacheElement;
+import org.dcache.nfs.util.CacheEventListener;
+import org.dcache.nfs.v4.xdr.clientid4;
+
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
+
+public class DefaultClientCache extends Cache<clientid4, NFS4Client> implements ClientCache {
+    public DefaultClientCache(int leaseTime, CacheEventListener<clientid4, NFS4Client> eventListener) {
+        super("NFSv41 clients", 5000, Long.MAX_VALUE,
+                TimeUnit.SECONDS.toMillis(leaseTime * 2),
+                eventListener);
+    }
+
+    @Override
+    public Stream<NFS4Client> stream() {
+        return entries().stream()
+                .map(CacheElement::getObject);
+    }
+
+    @Override
+    public Stream<NFS4Client> peek() {
+        return entries().stream()
+                .map(CacheElement::peekObject);
+    }
+}

core/src/main/java/org/dcache/nfs/v4/NFSv4StateHandler.java

@@ -45,7 +45,6 @@ import org.dcache.nfs.v4.xdr.stateid4;
 import org.dcache.nfs.v4.xdr.verifier4;
 import org.dcache.oncrpc4j.util.Bytes;
 import org.dcache.nfs.util.Cache;
-import org.dcache.nfs.util.CacheElement;
 import org.dcache.nfs.util.NopCacheEventListener;
 
 import static com.google.common.base.Preconditions.checkState;
@@ -65,7 +64,7 @@ public class NFSv4StateHandler {
     private final AtomicInteger _clientId = new AtomicInteger(0);
 
     // mapping between server generated clietid and nfs_client_id, not confirmed yet
-    private final Cache<clientid4, NFS4Client> _clientsByServerId;
+    private final ClientCache _clientsByServerId;
 
     /**
      * Client's lease expiration time in seconds.
@@ -101,10 +100,12 @@ public class NFSv4StateHandler {
      * @param clientStore store used by state handler to keep track of valid clients.
      */
     public NFSv4StateHandler(int leaseTime, int instanceId, ClientRecoveryStore clientStore) {
+        this(leaseTime, instanceId, clientStore, new DefaultClientCache(leaseTime, new DeadClientCollector(clientStore)));
+    }
+
+    public NFSv4StateHandler(int leaseTime, int instanceId, ClientRecoveryStore clientStore, ClientCache clientsByServerId) {
         _leaseTime = leaseTime;
-        _clientsByServerId = new Cache<>("NFSv41 clients", 5000, Long.MAX_VALUE,
-                TimeUnit.SECONDS.toMillis(_leaseTime * 2),
-                new DeadClientCollector());
+        _clientsByServerId = clientsByServerId;
 
         _running = true;
         _instanceId = instanceId;
@@ -230,9 +231,8 @@ public class NFSv4StateHandler {
      * @return an existing client record or null, if not matching record found.
      */
     public synchronized NFS4Client clientByOwner(byte[] ownerid) {
-        return _clientsByServerId.entries()
+        return _clientsByServerId
                 .stream()
-                .map(CacheElement::getObject)
                 .filter(c -> Arrays.equals(c.getOwnerId(), ownerid))
                 .findAny()
                 .orElse(null);
@@ -254,8 +254,7 @@ public class NFSv4StateHandler {
 
     public synchronized List<NFS4Client> getClients() {
         checkState(_running, "NFS state handler not running");
-        return _clientsByServerId.entries().stream()
-                .map(CacheElement::peekObject)
+        return _clientsByServerId.peek()
                 .collect(Collectors.toList());
     }
 
@@ -276,7 +275,12 @@ public class NFSv4StateHandler {
         return _openFileTracker;
     }
 
-    private class DeadClientCollector extends NopCacheEventListener<clientid4, NFS4Client> {
+    private static final class DeadClientCollector extends NopCacheEventListener<clientid4, NFS4Client> {
+        private final ClientRecoveryStore clientStore;
+
+        private DeadClientCollector(ClientRecoveryStore clientStore) {
+            this.clientStore = clientStore;
+        }
 
         @Override
         public void notifyExpired(Cache<clientid4, NFS4Client> cache, NFS4Client client) {
@@ -312,8 +316,7 @@ public class NFSv4StateHandler {
     }
 
     private synchronized void drainClients() {
-        _clientsByServerId.entries().stream()
-                .map(CacheElement::getObject)
+        _clientsByServerId.stream()
                 .forEach(c -> {
                     c.tryDispose();
                     _clientsByServerId.remove(c.getId());