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.AbstractRegistration;
  19 import org.opendaylight.yangtools.concepts.ObjectRegistration;
  20 import org.opendaylight.yangtools.concepts.Registration;
  21 import org.opendaylight.yangtools.yang.binding.YangModuleInfo;
  22 import org.opendaylight.yangtools.yang.parser.api.YangParserFactory;
  23 import org.osgi.service.component.ComponentFactory;
  24 import org.osgi.service.component.ComponentInstance;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27
  28 /**
  29  * Update SchemaContext service in Service Registry each time new YangModuleInfo is added or removed.
  30  */
  31 final class RegularYangModuleInfoRegistry extends YangModuleInfoRegistry {
  32     private static final Logger LOG = LoggerFactory.getLogger(RegularYangModuleInfoRegistry.class);
  33
  34     private final ComponentFactory<OSGiModuleInfoSnapshotImpl> contextFactory;
  35     private final ModuleInfoSnapshotResolver resolver;
  36
  37     @GuardedBy("this")
  38     private ComponentInstance<OSGiModuleInfoSnapshotImpl> currentInstance;
  39     @GuardedBy("this")
  40     private ModuleInfoSnapshot currentSnapshot;
  41     @GuardedBy("this")
  42     private int generation;
  43
  44     private volatile boolean ignoreScanner = true;
  45
  46     RegularYangModuleInfoRegistry(final ComponentFactory<OSGiModuleInfoSnapshotImpl> contextFactory,
  47             final YangParserFactory factory) {
  48         this.contextFactory = requireNonNull(contextFactory);
  49         resolver = new ModuleInfoSnapshotResolver("binding-dom-codec", factory);
  50     }
  51
  52     // Invocation from scanner, we may want to ignore this in order to not process partial updates
  53     @Override
  54     void scannerUpdate() {
  55         if (!ignoreScanner) {
  56             synchronized (this) {
  57                 updateService();
  58             }
  59         }
  60     }
  61
  62     @Override
  63     synchronized void scannerShutdown() {
  64         ignoreScanner = true;
  65     }
  66
  67     @Override
  68     synchronized void enableScannerAndUpdate() {
  69         ignoreScanner = false;
  70         updateService();
  71     }
  72
  73     @Override
  74     synchronized void close() {
  75         ignoreScanner = true;
  76         if (currentInstance != null) {
  77             currentInstance.dispose();
  78             currentInstance = null;
  79         }
  80     }
  81
  82     @Override
  83     Registration registerInfos(final List<YangModuleInfo> infos) {
  84         final var regs = resolver.registerModuleInfos(infos);
  85         return new AbstractRegistration() {
  86             @Override
  87             protected void removeRegistration() {
  88                 regs.forEach(ObjectRegistration::close);
  89             }
  90         };
  91     }
  92
  93     @Holding("this")
  94     private void updateService() {
  95         final ModuleInfoSnapshot newSnapshot;
  96         try {
  97             newSnapshot = resolver.takeSnapshot();
  98         } catch (NoSuchElementException e) {
  99             LOG.debug("No snapshot available", e);
 100             return;
 101         }
 102         if (newSnapshot.equals(currentSnapshot)) {
 103             LOG.debug("No update to snapshot");
 104             return;
 105         }
 106
 107
 108         final ComponentInstance<OSGiModuleInfoSnapshotImpl> newInstance = contextFactory.newInstance(
 109             OSGiModuleInfoSnapshotImpl.props(nextGeneration(), newSnapshot));
 110         if (currentInstance != null) {
 111             currentInstance.dispose();
 112         }
 113         currentInstance = newInstance;
 114         currentSnapshot = newSnapshot;
 115     }
 116
 117     @Holding("this")
 118     private long nextGeneration() {
 119         return generation == -1 ? -1 : ++generation;
 120     }
 121 }