dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/osgi/OsgiBundleScanningSchemaService.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.mdsal.dom.broker.osgi;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11
  12 import com.google.common.annotations.VisibleForTesting;
  13 import com.google.common.base.Optional;
  14 import com.google.common.base.Preconditions;
  15 import com.google.common.collect.ImmutableList;
  16 import com.google.common.collect.Iterables;
  17 import java.net.URL;
  18 import java.util.ArrayList;
  19 import java.util.Collections;
  20 import java.util.Enumeration;
  21 import java.util.List;
  22 import java.util.concurrent.atomic.AtomicReference;
  23 import javax.annotation.concurrent.GuardedBy;
  24 import org.opendaylight.mdsal.dom.api.DOMSchemaService;
  25 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  26 import org.opendaylight.yangtools.concepts.Registration;
  27 import org.opendaylight.yangtools.util.ListenerRegistry;
  28 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  29 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
  30 import org.opendaylight.yangtools.yang.model.api.SchemaContextProvider;
  31 import org.opendaylight.yangtools.yang.parser.repo.YangTextSchemaContextResolver;
  32 import org.osgi.framework.Bundle;
  33 import org.osgi.framework.BundleContext;
  34 import org.osgi.framework.BundleEvent;
  35 import org.osgi.framework.ServiceReference;
  36 import org.osgi.util.tracker.BundleTracker;
  37 import org.osgi.util.tracker.BundleTrackerCustomizer;
  38 import org.osgi.util.tracker.ServiceTracker;
  39 import org.osgi.util.tracker.ServiceTrackerCustomizer;
  40 import org.slf4j.Logger;
  41 import org.slf4j.LoggerFactory;
  42
  43 public class OsgiBundleScanningSchemaService implements SchemaContextProvider, DOMSchemaService,
  44         ServiceTrackerCustomizer<SchemaContextListener, SchemaContextListener>, AutoCloseable {
  45     private static final Logger LOG = LoggerFactory.getLogger(OsgiBundleScanningSchemaService.class);
  46
  47     private static AtomicReference<OsgiBundleScanningSchemaService> globalInstance = new AtomicReference<>();
  48
  49     @GuardedBy(value = "lock")
  50     private final ListenerRegistry<SchemaContextListener> listeners = new ListenerRegistry<>();
  51     private final YangTextSchemaContextResolver contextResolver = YangTextSchemaContextResolver.create("global-bundle");
  52     private final BundleScanner scanner = new BundleScanner();
  53     private final BundleContext context;
  54
  55     private ServiceTracker<SchemaContextListener, SchemaContextListener> listenerTracker;
  56     private BundleTracker<Iterable<Registration>> bundleTracker;
  57     private boolean starting = true;
  58     private volatile boolean stopping;
  59     private final Object lock = new Object();
  60
  61     private OsgiBundleScanningSchemaService(final BundleContext context) {
  62         this.context = Preconditions.checkNotNull(context);
  63     }
  64
  65     public static OsgiBundleScanningSchemaService createInstance(final BundleContext ctx) {
  66         OsgiBundleScanningSchemaService instance = new OsgiBundleScanningSchemaService(ctx);
  67         Preconditions.checkState(globalInstance.compareAndSet(null, instance));
  68         instance.start();
  69         return instance;
  70     }
  71
  72     public static OsgiBundleScanningSchemaService getInstance() {
  73         OsgiBundleScanningSchemaService instance = globalInstance.get();
  74         Preconditions.checkState(instance != null, "Global Instance was not instantiated");
  75         return instance;
  76     }
  77
  78     @VisibleForTesting
  79     public static void destroyInstance() {
  80         OsgiBundleScanningSchemaService instance = globalInstance.getAndSet(null);
  81         if (instance != null) {
  82             instance.close();
  83         }
  84     }
  85
  86     public BundleContext getContext() {
  87         return context;
  88     }
  89
  90     private void start() {
  91         checkState(context != null);
  92         LOG.debug("start() starting");
  93
  94         listenerTracker = new ServiceTracker<>(context, SchemaContextListener.class,
  95                 OsgiBundleScanningSchemaService.this);
  96         bundleTracker = new BundleTracker<>(context, Bundle.RESOLVED | Bundle.STARTING
  97                 | Bundle.STOPPING | Bundle.ACTIVE, scanner);
  98
  99         synchronized (lock) {
 100             bundleTracker.open();
 101
 102             LOG.debug("BundleTracker.open() complete");
 103
 104             boolean hasExistingListeners = Iterables.size(listeners.getListeners()) > 0;
 105             if (hasExistingListeners) {
 106                 tryToUpdateSchemaContext();
 107             }
 108         }
 109
 110         listenerTracker.open();
 111         starting = false;
 112
 113         LOG.debug("start() complete");
 114     }
 115
 116     @Override
 117     public SchemaContext getSchemaContext() {
 118         return getGlobalContext();
 119     }
 120
 121     @Override
 122     public SchemaContext getGlobalContext() {
 123         return contextResolver.getSchemaContext().orNull();
 124     }
 125
 126     @Override
 127     public SchemaContext getSessionContext() {
 128         throw new UnsupportedOperationException();
 129     }
 130
 131     @Override
 132     public ListenerRegistration<SchemaContextListener> registerSchemaContextListener(
 133             final SchemaContextListener listener) {
 134         synchronized (lock) {
 135             final Optional<SchemaContext> potentialCtx = contextResolver.getSchemaContext();
 136             if (potentialCtx.isPresent()) {
 137                 listener.onGlobalContextUpdated(potentialCtx.get());
 138             }
 139             return listeners.register(listener);
 140         }
 141     }
 142
 143     @Override
 144     public void close() {
 145         stopping = true;
 146         if (bundleTracker != null) {
 147             bundleTracker.close();
 148         }
 149         if (listenerTracker != null) {
 150             listenerTracker.close();
 151         }
 152
 153         for (final ListenerRegistration<SchemaContextListener> l : listeners.getListeners()) {
 154             l.close();
 155         }
 156     }
 157
 158     @SuppressWarnings("checkstyle:IllegalCatch")
 159     @VisibleForTesting
 160     @GuardedBy(value = "lock")
 161     void notifyListeners(final SchemaContext snapshot) {
 162         final Object[] services = listenerTracker.getServices();
 163         for (final ListenerRegistration<SchemaContextListener> listener : listeners) {
 164             try {
 165                 listener.getInstance().onGlobalContextUpdated(snapshot);
 166             } catch (final Exception e) {
 167                 LOG.error("Exception occured during invoking listener", e);
 168             }
 169         }
 170         if (services != null) {
 171             for (final Object rawListener : services) {
 172                 final SchemaContextListener listener = (SchemaContextListener) rawListener;
 173                 try {
 174                     listener.onGlobalContextUpdated(snapshot);
 175                 } catch (final Exception e) {
 176                     LOG.error("Exception occured during invoking listener {}", listener, e);
 177                 }
 178             }
 179         }
 180     }
 181
 182     @SuppressWarnings("checkstyle:IllegalCatch")
 183     private class BundleScanner implements BundleTrackerCustomizer<Iterable<Registration>> {
 184         @Override
 185         public Iterable<Registration> addingBundle(final Bundle bundle, final BundleEvent event) {
 186
 187             if (bundle.getBundleId() == 0) {
 188                 return Collections.emptyList();
 189             }
 190
 191             final Enumeration<URL> enumeration = bundle.findEntries("META-INF/yang", "*.yang", false);
 192             if (enumeration == null) {
 193                 return Collections.emptyList();
 194             }
 195
 196             final List<Registration> urls = new ArrayList<>();
 197             while (enumeration.hasMoreElements()) {
 198                 final URL u = enumeration.nextElement();
 199                 try {
 200                     urls.add(contextResolver.registerSource(u));
 201                     LOG.debug("Registered {}", u);
 202                 } catch (final Exception e) {
 203                     LOG.warn("Failed to register {}, ignoring it", e);
 204                 }
 205             }
 206
 207             if (!urls.isEmpty()) {
 208                 LOG.debug("Loaded {} new URLs from bundle {}, attempting to rebuild schema context",
 209                         urls.size(), bundle.getSymbolicName());
 210                 tryToUpdateSchemaContext();
 211             }
 212
 213             return ImmutableList.copyOf(urls);
 214         }
 215
 216         @Override
 217         public void modifiedBundle(final Bundle bundle, final BundleEvent event, final Iterable<Registration> object) {
 218         }
 219
 220         /**
 221          * If removing YANG files makes yang store inconsistent, method
 222          * {@link #getYangStoreSnapshot()} will throw exception. There is no
 223          * rollback.
 224          */
 225         @SuppressWarnings("checkstyle:IllegalCatch")
 226         @Override
 227         public void removedBundle(final Bundle bundle, final BundleEvent event, final Iterable<Registration> urls) {
 228             for (final Registration url : urls) {
 229                 try {
 230                     url.close();
 231                 } catch (final Exception e) {
 232                     LOG.warn("Failed do unregister URL {}, proceeding", url, e);
 233                 }
 234             }
 235
 236             final int numUrls = Iterables.size(urls);
 237             if (numUrls > 0 ) {
 238                 if (LOG.isDebugEnabled()) {
 239                     LOG.debug("removedBundle: {}, state: {}, # urls: {}", bundle.getSymbolicName(),
 240                             bundle.getState(), numUrls);
 241                 }
 242
 243                 tryToUpdateSchemaContext();
 244             }
 245         }
 246     }
 247
 248     @Override
 249     public SchemaContextListener addingService(final ServiceReference<SchemaContextListener> reference) {
 250
 251         final SchemaContextListener listener = context.getService(reference);
 252         final SchemaContext _ctxContext = getGlobalContext();
 253         if (getContext() != null && _ctxContext != null) {
 254             listener.onGlobalContextUpdated(_ctxContext);
 255         }
 256         return listener;
 257     }
 258
 259     public void tryToUpdateSchemaContext() {
 260         if (starting || stopping) {
 261             return;
 262         }
 263
 264         synchronized (lock) {
 265             final Optional<SchemaContext> schema = contextResolver.getSchemaContext();
 266             if (schema.isPresent()) {
 267                 if (LOG.isDebugEnabled()) {
 268                     LOG.debug("Got new SchemaContext: # of modules {}", schema.get().getAllModuleIdentifiers().size());
 269                 }
 270
 271                 notifyListeners(schema.get());
 272             }
 273         }
 274     }
 275
 276     @Override
 277     public void modifiedService(final ServiceReference<SchemaContextListener> reference,
 278             final SchemaContextListener service) {
 279         // NOOP
 280     }
 281
 282     @Override
 283     public void removedService(final ServiceReference<SchemaContextListener> reference,
 284             final SchemaContextListener service) {
 285         context.ungetService(reference);
 286     }
 287 }