opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/sal/dom/broker/GlobalBundleScanningSchemaServiceImpl.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.controller.sal.dom.broker;
   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 com.google.common.util.concurrent.CheckedFuture;
  18 import java.net.URL;
  19 import java.util.ArrayList;
  20 import java.util.Collections;
  21 import java.util.Enumeration;
  22 import java.util.List;
  23 import java.util.concurrent.atomic.AtomicReference;
  24 import javax.annotation.concurrent.GuardedBy;
  25 import org.opendaylight.controller.sal.core.api.model.SchemaService;
  26 import org.opendaylight.controller.sal.core.api.model.YangTextSourceProvider;
  27 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  28 import org.opendaylight.yangtools.concepts.Registration;
  29 import org.opendaylight.yangtools.util.ListenerRegistry;
  30 import org.opendaylight.yangtools.yang.model.api.Module;
  31 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  32 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
  33 import org.opendaylight.yangtools.yang.model.api.SchemaContextProvider;
  34 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceException;
  35 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  36 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  37 import org.opendaylight.yangtools.yang.parser.repo.URLSchemaContextResolver;
  38 import org.osgi.framework.Bundle;
  39 import org.osgi.framework.BundleContext;
  40 import org.osgi.framework.BundleEvent;
  41 import org.osgi.framework.ServiceReference;
  42 import org.osgi.util.tracker.BundleTracker;
  43 import org.osgi.util.tracker.BundleTrackerCustomizer;
  44 import org.osgi.util.tracker.ServiceTracker;
  45 import org.osgi.util.tracker.ServiceTrackerCustomizer;
  46 import org.slf4j.Logger;
  47 import org.slf4j.LoggerFactory;
  48
  49 public class GlobalBundleScanningSchemaServiceImpl implements SchemaContextProvider, SchemaService, ServiceTrackerCustomizer<SchemaContextListener, SchemaContextListener>, YangTextSourceProvider, AutoCloseable {
  50     private static final Logger LOG = LoggerFactory.getLogger(GlobalBundleScanningSchemaServiceImpl.class);
  51
  52     private static AtomicReference<GlobalBundleScanningSchemaServiceImpl> globalInstance = new AtomicReference<>();
  53
  54     @GuardedBy(value = "lock")
  55     private final ListenerRegistry<SchemaContextListener> listeners = new ListenerRegistry<>();
  56     private final URLSchemaContextResolver contextResolver = URLSchemaContextResolver.create("global-bundle");
  57     private final BundleScanner scanner = new BundleScanner();
  58     private final BundleContext context;
  59
  60     private ServiceTracker<SchemaContextListener, SchemaContextListener> listenerTracker;
  61     private BundleTracker<Iterable<Registration>> bundleTracker;
  62     private boolean starting = true;
  63     private volatile boolean stopping;
  64     private final Object lock = new Object();
  65
  66     private GlobalBundleScanningSchemaServiceImpl(final BundleContext context) {
  67         this.context = Preconditions.checkNotNull(context);
  68     }
  69
  70     public static GlobalBundleScanningSchemaServiceImpl createInstance(final BundleContext ctx) {
  71         GlobalBundleScanningSchemaServiceImpl instance = new GlobalBundleScanningSchemaServiceImpl(ctx);
  72         Preconditions.checkState(globalInstance.compareAndSet(null, instance));
  73         instance.start();
  74         return instance;
  75     }
  76
  77     public static GlobalBundleScanningSchemaServiceImpl getInstance() {
  78         GlobalBundleScanningSchemaServiceImpl instance = globalInstance.get();
  79         Preconditions.checkState(instance != null, "Global Instance was not instantiated");
  80         return instance;
  81     }
  82
  83     @VisibleForTesting
  84     public static void destroyInstance() {
  85         GlobalBundleScanningSchemaServiceImpl instance = globalInstance.getAndSet(null);
  86         if(instance != null) {
  87             instance.close();
  88         }
  89     }
  90
  91     public BundleContext getContext() {
  92         return context;
  93     }
  94
  95     public void start() {
  96         checkState(context != null);
  97         LOG.debug("start() starting");
  98
  99         listenerTracker = new ServiceTracker<>(context, SchemaContextListener.class, GlobalBundleScanningSchemaServiceImpl.this);
 100         bundleTracker = new BundleTracker<>(context, Bundle.RESOLVED | Bundle.STARTING |
 101                 Bundle.STOPPING | Bundle.ACTIVE, scanner);
 102
 103         synchronized(lock) {
 104             bundleTracker.open();
 105
 106             LOG.debug("BundleTracker.open() complete");
 107
 108             boolean hasExistingListeners = Iterables.size(listeners.getListeners()) > 0;
 109             if(hasExistingListeners) {
 110                 tryToUpdateSchemaContext();
 111             }
 112         }
 113
 114         listenerTracker.open();
 115         starting = false;
 116
 117         LOG.debug("start() complete");
 118     }
 119
 120     @Override
 121     public SchemaContext getSchemaContext() {
 122         return getGlobalContext();
 123     }
 124
 125     @Override
 126     public SchemaContext getGlobalContext() {
 127         return contextResolver.getSchemaContext().orNull();
 128     }
 129
 130     @Override
 131     public void addModule(final Module module) {
 132         throw new UnsupportedOperationException();
 133     }
 134
 135     @Override
 136     public SchemaContext getSessionContext() {
 137         throw new UnsupportedOperationException();
 138     }
 139
 140     @Override
 141     public void removeModule(final Module module) {
 142         throw new UnsupportedOperationException();
 143     }
 144
 145     @Override
 146     public ListenerRegistration<SchemaContextListener> registerSchemaContextListener(final SchemaContextListener listener) {
 147         synchronized(lock) {
 148             Optional<SchemaContext> potentialCtx = contextResolver.getSchemaContext();
 149             if(potentialCtx.isPresent()) {
 150                 listener.onGlobalContextUpdated(potentialCtx.get());
 151             }
 152             return listeners.register(listener);
 153         }
 154     }
 155
 156     @Override
 157     public void close() {
 158         stopping = true;
 159         if (bundleTracker != null) {
 160             bundleTracker.close();
 161         }
 162         if (listenerTracker != null) {
 163             listenerTracker.close();
 164         }
 165
 166         for (ListenerRegistration<SchemaContextListener> l : listeners.getListeners()) {
 167             l.close();
 168         }
 169     }
 170
 171     @GuardedBy(value = "lock")
 172     private void notifyListeners(final SchemaContext snapshot) {
 173         Object[] services = listenerTracker.getServices();
 174         for (ListenerRegistration<SchemaContextListener> listener : listeners) {
 175             try {
 176                 listener.getInstance().onGlobalContextUpdated(snapshot);
 177             } catch (Exception e) {
 178                 LOG.error("Exception occured during invoking listener", e);
 179             }
 180         }
 181         if (services != null) {
 182             for (Object rawListener : services) {
 183                 final SchemaContextListener listener = (SchemaContextListener) rawListener;
 184                 try {
 185                     listener.onGlobalContextUpdated(snapshot);
 186                 } catch (Exception e) {
 187                     LOG.error("Exception occured during invoking listener {}", listener, e);
 188                 }
 189             }
 190         }
 191     }
 192
 193     @Override
 194     public CheckedFuture<YangTextSchemaSource, SchemaSourceException> getSource(final SourceIdentifier sourceIdentifier) {
 195         return contextResolver.getSource(sourceIdentifier);
 196
 197     }
 198
 199     private class BundleScanner implements BundleTrackerCustomizer<Iterable<Registration>> {
 200         @Override
 201         public Iterable<Registration> addingBundle(final Bundle bundle, final BundleEvent event) {
 202
 203             if (bundle.getBundleId() == 0) {
 204                 return Collections.emptyList();
 205             }
 206
 207             final Enumeration<URL> enumeration = bundle.findEntries("META-INF/yang", "*.yang", false);
 208             if (enumeration == null) {
 209                 return Collections.emptyList();
 210             }
 211
 212             final List<Registration> urls = new ArrayList<>();
 213             while (enumeration.hasMoreElements()) {
 214                 final URL u = enumeration.nextElement();
 215                 try {
 216                     urls.add(contextResolver.registerSource(u));
 217                     LOG.debug("Registered {}", u);
 218                 } catch (Exception e) {
 219                     LOG.warn("Failed to register {}, ignoring it", e);
 220                 }
 221             }
 222
 223             if (!urls.isEmpty()) {
 224                 LOG.debug("Loaded {} new URLs from bundle {}, attempting to rebuild schema context",
 225                         urls.size(), bundle.getSymbolicName());
 226                 tryToUpdateSchemaContext();
 227             }
 228
 229             return ImmutableList.copyOf(urls);
 230         }
 231
 232         @Override
 233         public void modifiedBundle(final Bundle bundle, final BundleEvent event, final Iterable<Registration> object) {
 234         }
 235
 236         /**
 237          * If removing YANG files makes yang store inconsistent, method
 238          * {@link #getYangStoreSnapshot()} will throw exception. There is no
 239          * rollback.
 240          */
 241
 242         @Override
 243         public void removedBundle(final Bundle bundle, final BundleEvent event, final Iterable<Registration> urls) {
 244             for (Registration url : urls) {
 245                 try {
 246                     url.close();
 247                 } catch (Exception e) {
 248                     LOG.warn("Failed do unregister URL {}, proceeding", url, e);
 249                 }
 250             }
 251
 252             int numUrls = Iterables.size(urls);
 253             if(numUrls > 0 ) {
 254                 if(LOG.isDebugEnabled()) {
 255                     LOG.debug("removedBundle: {}, state: {}, # urls: {}", bundle.getSymbolicName(), bundle.getState(), numUrls);
 256                 }
 257
 258                 tryToUpdateSchemaContext();
 259             }
 260         }
 261     }
 262
 263     @Override
 264     public SchemaContextListener addingService(final ServiceReference<SchemaContextListener> reference) {
 265
 266         SchemaContextListener listener = context.getService(reference);
 267         SchemaContext _ctxContext = getGlobalContext();
 268         if (getContext() != null && _ctxContext != null) {
 269             listener.onGlobalContextUpdated(_ctxContext);
 270         }
 271         return listener;
 272     }
 273
 274     public void tryToUpdateSchemaContext() {
 275         if (starting || stopping) {
 276             return;
 277         }
 278
 279         synchronized(lock) {
 280             Optional<SchemaContext> schema = contextResolver.getSchemaContext();
 281             if(schema.isPresent()) {
 282                 if(LOG.isDebugEnabled()) {
 283                     LOG.debug("Got new SchemaContext: # of modules {}", schema.get().getAllModuleIdentifiers().size());
 284                 }
 285
 286                 notifyListeners(schema.get());
 287             }
 288         }
 289     }
 290
 291     @Override
 292     public void modifiedService(final ServiceReference<SchemaContextListener> reference, final SchemaContextListener service) {
 293         // NOOP
 294     }
 295
 296     @Override
 297     public void removedService(final ServiceReference<SchemaContextListener> reference, final SchemaContextListener service) {
 298         context.ungetService(reference);
 299     }
 300 }