dom/mdsal-dom-schema-osgi/src/main/java/org/opendaylight/mdsal/dom/schema/osgi/impl/RegularYangModuleInfoRegistry.java

   1 /*
   2  * Copyright (c) 2017, 2020 PANTHEON.tech, s.r.o. 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.schema.osgi.impl;
   9
  10 import static java.util.Objects.requireNonNull;
  11
  12 import java.util.List;
  13 import java.util.NoSuchElementException;
  14 import org.checkerframework.checker.lock.qual.GuardedBy;
  15 import org.checkerframework.checker.lock.qual.Holding;
  16 import org.opendaylight.mdsal.binding.runtime.api.ModuleInfoSnapshot;
  17 import org.opendaylight.mdsal.binding.runtime.spi.ModuleInfoSnapshotResolver;
  18 import org.opendaylight.yangtools.concepts.ObjectRegistration;
  19 import org.opendaylight.yangtools.yang.binding.YangModuleInfo;
  20 import org.opendaylight.yangtools.yang.parser.api.YangParserFactory;
  21 import org.osgi.service.component.ComponentFactory;
  22 import org.osgi.service.component.ComponentInstance;
  23 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25
  26 /**
  27  * Update SchemaContext service in Service Registry each time new YangModuleInfo is added or removed.
  28  */
  29 final class RegularYangModuleInfoRegistry extends YangModuleInfoRegistry {
  30     private static final Logger LOG = LoggerFactory.getLogger(RegularYangModuleInfoRegistry.class);
  31
  32     private final ComponentFactory<OSGiModuleInfoSnapshotImpl> contextFactory;
  33     private final ModuleInfoSnapshotResolver moduleInfoRegistry;
  34
  35     @GuardedBy("this")
  36     private ComponentInstance<OSGiModuleInfoSnapshotImpl> currentInstance;
  37     @GuardedBy("this")
  38     private ModuleInfoSnapshot currentSnapshot;
  39     @GuardedBy("this")
  40     private int generation;
  41
  42     private volatile boolean ignoreScanner = true;
  43
  44     RegularYangModuleInfoRegistry(final ComponentFactory<OSGiModuleInfoSnapshotImpl> contextFactory,
  45             final YangParserFactory factory) {
  46         this.contextFactory = requireNonNull(contextFactory);
  47         moduleInfoRegistry = new ModuleInfoSnapshotResolver("binding-dom-codec", factory);
  48     }
  49
  50     // Invocation from scanner, we may want to ignore this in order to not process partial updates
  51     @Override
  52     void scannerUpdate() {
  53         if (!ignoreScanner) {
  54             synchronized (this) {
  55                 updateService();
  56             }
  57         }
  58     }
  59
  60     @Override
  61     synchronized void scannerShutdown() {
  62         ignoreScanner = true;
  63     }
  64
  65     @Override
  66     synchronized void enableScannerAndUpdate() {
  67         ignoreScanner = false;
  68         updateService();
  69     }
  70
  71     @Override
  72     synchronized void close() {
  73         ignoreScanner = true;
  74         if (currentInstance != null) {
  75             currentInstance.dispose();
  76             currentInstance = null;
  77         }
  78     }
  79
  80     @Override
  81     List<ObjectRegistration<YangModuleInfo>> registerInfos(final List<YangModuleInfo> infos) {
  82         return moduleInfoRegistry.registerModuleInfos(infos);
  83     }
  84
  85     @Holding("this")
  86     private void updateService() {
  87         final ModuleInfoSnapshot newSnapshot;
  88         try {
  89             newSnapshot = moduleInfoRegistry.takeSnapshot();
  90         } catch (NoSuchElementException e) {
  91             LOG.debug("No snapshot available", e);
  92             return;
  93         }
  94         if (newSnapshot.equals(currentSnapshot)) {
  95             LOG.debug("No update to snapshot");
  96             return;
  97         }
  98
  99
 100         final ComponentInstance<OSGiModuleInfoSnapshotImpl> newInstance = contextFactory.newInstance(
 101             OSGiModuleInfoSnapshotImpl.props(nextGeneration(), newSnapshot));
 102         if (currentInstance != null) {
 103             currentInstance.dispose();
 104         }
 105         currentInstance = newInstance;
 106         currentSnapshot = newSnapshot;
 107     }
 108
 109     @Holding("this")
 110     private long nextGeneration() {
 111         return generation == -1 ? -1 : ++generation;
 112     }
 113 }