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 final AtomicReference<OsgiBundleScanningSchemaService> GLOBAL_INSTANCE = new AtomicReference<>();
  48
  49     private static final long FRAMEWORK_BUNDLE_ID = 0;
  50
  51     @GuardedBy("lock")
  52     private final ListenerRegistry<SchemaContextListener> listeners = new ListenerRegistry<>();
  53     private final YangTextSchemaContextResolver contextResolver = YangTextSchemaContextResolver.create("global-bundle");
  54     private final BundleScanner scanner = new BundleScanner();
  55     private final Object lock = new Object();
  56     private final BundleContext context;
  57
  58     private ServiceTracker<SchemaContextListener, SchemaContextListener> listenerTracker;
  59     private BundleTracker<Iterable<Registration>> bundleTracker;
  60     private boolean starting = true;
  61
  62     private volatile boolean stopping;
  63
  64     private OsgiBundleScanningSchemaService(final BundleContext context) {
  65         this.context = Preconditions.checkNotNull(context);
  66     }
  67
  68     public static OsgiBundleScanningSchemaService createInstance(final BundleContext ctx) {
  69         OsgiBundleScanningSchemaService instance = new OsgiBundleScanningSchemaService(ctx);
  70         Preconditions.checkState(GLOBAL_INSTANCE.compareAndSet(null, instance));
  71         instance.start();
  72         return instance;
  73     }
  74
  75     public static OsgiBundleScanningSchemaService getInstance() {
  76         OsgiBundleScanningSchemaService instance = GLOBAL_INSTANCE.get();
  77         Preconditions.checkState(instance != null, "Global Instance was not instantiated");
  78         return instance;
  79     }
  80
  81     @VisibleForTesting
  82     public static void destroyInstance() {
  83         OsgiBundleScanningSchemaService instance = GLOBAL_INSTANCE.getAndSet(null);
  84         if (instance != null) {
  85             instance.close();
  86         }
  87     }
  88
  89     public BundleContext getContext() {
  90         return context;
  91     }
  92
  93     private void start() {
  94         checkState(context != null);
  95         LOG.debug("start() starting");
  96
  97         listenerTracker = new ServiceTracker<>(context, SchemaContextListener.class, this);
  98         bundleTracker = new BundleTracker<>(context, Bundle.RESOLVED | Bundle.STARTING
  99                 | Bundle.STOPPING | Bundle.ACTIVE, scanner);
 100
 101         synchronized (lock) {
 102             bundleTracker.open();
 103
 104             LOG.debug("BundleTracker.open() complete");
 105
 106             if (Iterables.size(listeners.getListeners()) > 0) {
 107                 tryToUpdateSchemaContext();
 108             }
 109         }
 110
 111         listenerTracker.open();
 112         starting = false;
 113
 114         LOG.debug("start() complete");
 115     }
 116
 117     @Override
 118     public SchemaContext getSchemaContext() {
 119         return getGlobalContext();
 120     }
 121
 122     @Override
 123     public SchemaContext getGlobalContext() {
 124         return contextResolver.getSchemaContext().orNull();
 125     }
 126
 127     @Override
 128     public SchemaContext getSessionContext() {
 129         throw new UnsupportedOperationException();
 130     }
 131
 132     @Override
 133     public ListenerRegistration<SchemaContextListener> registerSchemaContextListener(
 134             final SchemaContextListener listener) {
 135         synchronized (lock) {
 136             final Optional<SchemaContext> potentialCtx = contextResolver.getSchemaContext();
 137             if (potentialCtx.isPresent()) {
 138                 listener.onGlobalContextUpdated(potentialCtx.get());
 139             }
 140             return listeners.register(listener);
 141         }
 142     }
 143
 144     @Override
 145     public void close() {
 146         synchronized (lock) {
 147             stopping = true;
 148             if (bundleTracker != null) {
 149                 bundleTracker.close();
 150                 bundleTracker = null;
 151             }
 152             if (listenerTracker != null) {
 153                 listenerTracker.close();
 154                 listenerTracker = null;
 155             }
 156
 157             for (final ListenerRegistration<SchemaContextListener> l : listeners.getListeners()) {
 158                 l.close();
 159             }
 160         }
 161     }
 162
 163     @SuppressWarnings("checkstyle:IllegalCatch")
 164     @VisibleForTesting
 165     @GuardedBy("lock")
 166     void notifyListeners(final SchemaContext snapshot) {
 167         final Object[] services = listenerTracker.getServices();
 168         for (final ListenerRegistration<SchemaContextListener> listener : listeners) {
 169             try {
 170                 listener.getInstance().onGlobalContextUpdated(snapshot);
 171             } catch (final Exception e) {
 172                 LOG.error("Exception occured during invoking listener", e);
 173             }
 174         }
 175         if (services != null) {
 176             for (final Object rawListener : services) {
 177                 final SchemaContextListener listener = (SchemaContextListener) rawListener;
 178                 try {
 179                     listener.onGlobalContextUpdated(snapshot);
 180                 } catch (final Exception e) {
 181                     LOG.error("Exception occured during invoking listener {}", listener, e);
 182                 }
 183             }
 184         }
 185     }
 186
 187     @SuppressWarnings("checkstyle:IllegalCatch")
 188     private class BundleScanner implements BundleTrackerCustomizer<Iterable<Registration>> {
 189         @Override
 190         public Iterable<Registration> addingBundle(final Bundle bundle, final BundleEvent event) {
 191
 192             if (bundle.getBundleId() == FRAMEWORK_BUNDLE_ID) {
 193                 return Collections.emptyList();
 194             }
 195
 196             final Enumeration<URL> enumeration = bundle.findEntries("META-INF/yang", "*.yang", false);
 197             if (enumeration == null) {
 198                 return Collections.emptyList();
 199             }
 200
 201             final List<Registration> urls = new ArrayList<>();
 202             while (enumeration.hasMoreElements()) {
 203                 final URL u = enumeration.nextElement();
 204                 try {
 205                     urls.add(contextResolver.registerSource(u));
 206                     LOG.debug("Registered {}", u);
 207                 } catch (final Exception e) {
 208                     LOG.warn("Failed to register {}, ignoring it", e);
 209                 }
 210             }
 211
 212             if (!urls.isEmpty()) {
 213                 LOG.debug("Loaded {} new URLs from bundle {}, attempting to rebuild schema context",
 214                         urls.size(), bundle.getSymbolicName());
 215                 tryToUpdateSchemaContext();
 216             }
 217
 218             return ImmutableList.copyOf(urls);
 219         }
 220
 221         @Override
 222         public void modifiedBundle(final Bundle bundle, final BundleEvent event, final Iterable<Registration> object) {
 223             if (bundle.getBundleId() == FRAMEWORK_BUNDLE_ID) {
 224                 LOG.debug("Framework bundle {} got event {}", bundle, event.getType());
 225                 if ((event.getType() & BundleEvent.STOPPING) != 0) {
 226                     LOG.info("OSGi framework is being stopped, halting bundle scanning");
 227                     stopping = true;
 228                 }
 229             }
 230         }
 231
 232         /**
 233          * If removing YANG files makes yang store inconsistent, method
 234          * {@link #getYangStoreSnapshot()} will throw exception. There is no
 235          * rollback.
 236          */
 237         @SuppressWarnings("checkstyle:IllegalCatch")
 238         @Override
 239         public void removedBundle(final Bundle bundle, final BundleEvent event, final Iterable<Registration> urls) {
 240             for (final Registration url : urls) {
 241                 try {
 242                     url.close();
 243                 } catch (final Exception e) {
 244                     LOG.warn("Failed do unregister URL {}, proceeding", url, e);
 245                 }
 246             }
 247
 248             final int numUrls = Iterables.size(urls);
 249             if (numUrls > 0 ) {
 250                 if (LOG.isDebugEnabled()) {
 251                     LOG.debug("removedBundle: {}, state: {}, # urls: {}", bundle.getSymbolicName(),
 252                             bundle.getState(), numUrls);
 253                 }
 254
 255                 tryToUpdateSchemaContext();
 256             }
 257         }
 258     }
 259
 260     @Override
 261     public SchemaContextListener addingService(final ServiceReference<SchemaContextListener> reference) {
 262
 263         final SchemaContextListener listener = context.getService(reference);
 264         final SchemaContext _ctxContext = getGlobalContext();
 265         if (getContext() != null && _ctxContext != null) {
 266             listener.onGlobalContextUpdated(_ctxContext);
 267         }
 268         return listener;
 269     }
 270
 271     public void tryToUpdateSchemaContext() {
 272         if (starting || stopping) {
 273             return;
 274         }
 275
 276         synchronized (lock) {
 277             final Optional<SchemaContext> schema = contextResolver.getSchemaContext();
 278             if (schema.isPresent()) {
 279                 if (LOG.isDebugEnabled()) {
 280                     LOG.debug("Got new SchemaContext: # of modules {}", schema.get().getAllModuleIdentifiers().size());
 281                 }
 282
 283                 notifyListeners(schema.get());
 284             }
 285         }
 286     }
 287
 288     @Override
 289     public void modifiedService(final ServiceReference<SchemaContextListener> reference,
 290             final SchemaContextListener service) {
 291         // NOOP
 292     }
 293
 294     @Override
 295     public void removedService(final ServiceReference<SchemaContextListener> reference,
 296             final SchemaContextListener service) {
 297         context.ungetService(reference);
 298     }
 299 }