Replace Preconditions.CheckNotNull per RequireNonNull
[bgpcep.git] / bgp / bmp-impl / src / main / java / org / opendaylight / protocol / bmp / impl / app / BmpRouterImpl.java
index c5f5bd76fe28616959a564ba75fc6bcf74f27212..fe95c515ded5d85856b5bfdffe1d74830f247b73 100644 (file)
@@ -8,13 +8,15 @@
 
 package org.opendaylight.protocol.bmp.impl.app;
 
-import com.google.common.base.Optional;
+import static java.util.Objects.requireNonNull;
+
 import com.google.common.base.Preconditions;
 import com.google.common.net.InetAddresses;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import javax.annotation.concurrent.GuardedBy;
 import org.opendaylight.controller.md.sal.common.api.data.AsyncTransaction;
 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
@@ -24,6 +26,7 @@ import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFaile
 import org.opendaylight.controller.md.sal.dom.api.DOMDataBroker;
 import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
 import org.opendaylight.controller.md.sal.dom.api.DOMTransactionChain;
+import org.opendaylight.mdsal.binding.dom.codec.api.BindingCodecTree;
 import org.opendaylight.protocol.bgp.rib.spi.RIBExtensionConsumerContext;
 import org.opendaylight.protocol.bmp.api.BmpSession;
 import org.opendaylight.protocol.bmp.impl.spi.BmpRouter;
@@ -39,7 +42,6 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bmp.mess
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bmp.monitor.rev150512.RouterId;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bmp.monitor.rev150512.peers.Peer;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bmp.monitor.rev150512.routers.Router;
-import org.opendaylight.yangtools.binding.data.codec.api.BindingCodecTree;
 import org.opendaylight.yangtools.yang.binding.Notification;
 import org.opendaylight.yangtools.yang.common.QName;
 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
@@ -53,11 +55,11 @@ public class BmpRouterImpl implements BmpRouter, TransactionChainListener {
 
     private static final Logger LOG = LoggerFactory.getLogger(BmpRouterImpl.class);
 
-    private static final QName ROUTER_ID_QNAME = QName.cachedReference(QName.create(Router.QNAME, "router-id"));
-    private static final QName ROUTER_STATUS_QNAME = QName.cachedReference(QName.create(Router.QNAME, "status"));
-    private static final QName ROUTER_NAME_QNAME = QName.cachedReference(QName.create(Router.QNAME, "name"));
-    private static final QName ROUTER_DESCRIPTION_QNAME = QName.cachedReference(QName.create(Router.QNAME, "description"));
-    private static final QName ROUTER_INFO_QNAME = QName.cachedReference(QName.create(Router.QNAME, "info"));
+    private static final QName ROUTER_ID_QNAME = QName.create(Router.QNAME, "router-id").intern();
+    private static final QName ROUTER_STATUS_QNAME = QName.create(Router.QNAME, "status").intern();
+    private static final QName ROUTER_NAME_QNAME = QName.create(Router.QNAME, "name").intern();
+    private static final QName ROUTER_DESCRIPTION_QNAME = QName.create(Router.QNAME, "description").intern();
+    private static final QName ROUTER_INFO_QNAME = QName.create(Router.QNAME, "info").intern();
     private static final String UP = "up";
     private static final String DOWN = "down";
 
@@ -75,9 +77,9 @@ public class BmpRouterImpl implements BmpRouter, TransactionChainListener {
     private YangInstanceIdentifier peersYangIId;
 
     public BmpRouterImpl(final RouterSessionManager sessionManager) {
-        this.sessionManager = Preconditions.checkNotNull(sessionManager);
+        this.sessionManager = requireNonNull(sessionManager);
         this.domDataBroker = sessionManager.getDomDataBroker();
-        this.domTxChain = sessionManager.getDomDataBroker().createTransactionChain(this);
+        this.domTxChain = this.domDataBroker.createTransactionChain(this);
         this.extensions = sessionManager.getExtensions();
         this.tree = sessionManager.getCodecTree();
     }
@@ -85,23 +87,31 @@ public class BmpRouterImpl implements BmpRouter, TransactionChainListener {
     @Override
     public void onSessionUp(final BmpSession session) {
         this.session = session;
-        this.routerIp = InetAddresses.toAddrString(session.getRemoteAddress());
-        this.routerId = new RouterId(Ipv4Util.getIpAddress(session.getRemoteAddress()));
-        this.routerYangIId = YangInstanceIdentifier.builder(this.sessionManager.getRoutersYangIId()).nodeWithKey(Router.QNAME,
-                ROUTER_ID_QNAME, this.routerIp).build();
-        this.peersYangIId = YangInstanceIdentifier.builder(routerYangIId).node(Peer.QNAME).build();
-        createRouterEntry();
-        this.sessionManager.addSessionListener(this);
+        this.routerIp = InetAddresses.toAddrString(this.session.getRemoteAddress());
+        this.routerId = new RouterId(Ipv4Util.getIpAddress(this.session.getRemoteAddress()));
+        // check if this session is redundant
+        if (!this.sessionManager.addSessionListener(this)) {
+            LOG.warn("Redundant BMP session with remote router {} ({}) detected. This BMP session will be abandoned.",
+                this.routerIp, this.session);
+            this.close();
+        } else {
+            this.routerYangIId = YangInstanceIdentifier.builder(this.sessionManager.getRoutersYangIId())
+                .nodeWithKey(Router.QNAME, ROUTER_ID_QNAME, this.routerIp).build();
+            this.peersYangIId = YangInstanceIdentifier.builder(this.routerYangIId).node(Peer.QNAME).build();
+            createRouterEntry();
+            LOG.info("BMP session with remote router {} ({}) is up now.", this.routerIp, this.session);
+        }
     }
 
     @Override
-    public void onSessionDown(final BmpSession session, final Exception e) {
-        LOG.info("Session {} went down.", session);
+    public void onSessionDown(final Exception e) {
+        // we want to tear down as we want to do clean up like closing the transaction chain, etc.
+        // even when datastore is not writable (routerYangIId == null / redundant session)
         tearDown();
     }
 
     @Override
-    public void onMessage(final BmpSession session, final Notification message) {
+    public void onMessage(final Notification message) {
         if (message instanceof InitiationMessage) {
             onInitiate((InitiationMessage) message);
         } else if (message instanceof PeerUpNotification) {
@@ -113,18 +123,30 @@ public class BmpRouterImpl implements BmpRouter, TransactionChainListener {
 
     @Override
     public RouterId getRouterId() {
-        return routerId;
+        return this.routerId;
     }
 
     @Override
-    public synchronized void close() throws Exception {
+    public synchronized void close() {
         if (this.session != null) {
-            this.session.close();
+            try {
+                this.session.close();
+            } catch (final Exception e) {
+                LOG.error("Fail to close session.", e);
+            }
         }
     }
 
     @GuardedBy("this")
     private synchronized void tearDown() {
+        // the session has been teared down before
+        if (this.session == null) {
+            return;
+        }
+        // we want to display remote router's IP here, as sometimes this.session.close() is already
+        // invoked before tearDown(), and session channel is null in this case, which leads to unuseful
+        // log information
+        LOG.info("BMP Session with remote router {} ({}) went down.", this.routerIp, this.session);
         this.session = null;
         final Iterator<BmpRouterPeer> it = this.peers.values().iterator();
         try {
@@ -136,39 +158,52 @@ public class BmpRouterImpl implements BmpRouter, TransactionChainListener {
         } catch(final Exception e) {
             LOG.error("Failed to properly close BMP application.", e);
         } finally {
-            try {
-                final DOMDataWriteTransaction wTx = this.domDataBroker.newWriteOnlyTransaction();
-                wTx.delete(LogicalDatastoreType.OPERATIONAL, this.routerYangIId);
-                wTx.submit().checkedGet();
-            } catch (final TransactionCommitFailedException e) {
-                LOG.error("Failed to remove BMP router data from DS.", e);
+            // remove session only when session is valid, otherwise
+            // we would remove the original valid session when a redundant connection happens
+            // as the routerId is the same for both connection
+            if (isDatastoreWritable()) {
+                try {
+                    // it means the session was closed before it was written to datastore
+                    final DOMDataWriteTransaction wTx = this.domDataBroker.newWriteOnlyTransaction();
+                    wTx.delete(LogicalDatastoreType.OPERATIONAL, this.routerYangIId);
+                    wTx.submit().checkedGet();
+                } catch (final TransactionCommitFailedException e) {
+                    LOG.error("Failed to remove BMP router data from DS.", e);
+                }
+                this.sessionManager.removeSessionListener(this);
             }
         }
-        this.sessionManager.removeSessionListener(this);
     }
 
     @Override
-    public void onTransactionChainFailed(final TransactionChain<?, ?> chain, final AsyncTransaction<?, ?> transaction, final Throwable cause) {
+    public void onTransactionChainFailed(final TransactionChain<?, ?> chain, final AsyncTransaction<?, ?> transaction,
+        final Throwable cause) {
         LOG.error("Transaction chain failed.", cause);
     }
 
     @Override
     public void onTransactionChainSuccessful(final TransactionChain<?, ?> chain) {
-        LOG.debug("Transaction chain {} successfull.", chain);
+        LOG.debug("Transaction chain {} successfully.", chain);
+    }
+
+    private boolean isDatastoreWritable() {
+        return (this.routerYangIId != null);
     }
 
-    private void createRouterEntry() {
+    private synchronized void createRouterEntry() {
+        Preconditions.checkState(isDatastoreWritable());
         final DOMDataWriteTransaction wTx = this.domTxChain.newWriteOnlyTransaction();
         wTx.put(LogicalDatastoreType.OPERATIONAL, this.routerYangIId,
                 Builders.mapEntryBuilder()
                 .withNodeIdentifier(new NodeIdentifierWithPredicates(Router.QNAME, ROUTER_ID_QNAME, this.routerIp))
-                .withChild(ImmutableNodes.leafNode(ROUTER_ID_QNAME, routerIp))
+                .withChild(ImmutableNodes.leafNode(ROUTER_ID_QNAME, this.routerIp))
                 .withChild(ImmutableNodes.leafNode(ROUTER_STATUS_QNAME, DOWN))
                 .withChild(ImmutableNodes.mapNodeBuilder(Peer.QNAME).build()).build());
         wTx.submit();
     }
 
-    private void onInitiate(final InitiationMessage initiation) {
+    private synchronized void onInitiate(final InitiationMessage initiation) {
+        Preconditions.checkState(isDatastoreWritable());
         final DOMDataWriteTransaction wTx = this.domTxChain.newWriteOnlyTransaction();
         wTx.merge(LogicalDatastoreType.OPERATIONAL, this.routerYangIId,
                 Builders.mapEntryBuilder()
@@ -183,7 +218,8 @@ public class BmpRouterImpl implements BmpRouter, TransactionChainListener {
     private void onPeerUp(final PeerUpNotification peerUp) {
         final PeerId peerId = getPeerIdFromOpen(peerUp.getReceivedOpen());
         if (!getPeer(peerId).isPresent()) {
-            final BmpRouterPeer peer = BmpRouterPeerImpl.createRouterPeer(this.domTxChain, this.peersYangIId, peerUp, this.extensions, this.tree, peerId);
+            final BmpRouterPeer peer = BmpRouterPeerImpl.createRouterPeer(this.domTxChain, this.peersYangIId, peerUp,
+                this.extensions, this.tree, peerId);
             this.peers.put(peerId, peer);
             LOG.debug("Router {}: Peer {} goes up.", this.routerIp, peerId.getValue());
         } else {
@@ -206,7 +242,7 @@ public class BmpRouterImpl implements BmpRouter, TransactionChainListener {
     }
 
     private Optional<BmpRouterPeer> getPeer(final PeerId peerId) {
-        return Optional.fromNullable(this.peers.get(peerId));
+        return Optional.ofNullable(this.peers.get(peerId));
     }
 
     private static PeerId getPeerId(final PeerHeader peerHeader) {