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.model.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 contextFactory;
  33     private final ModuleInfoSnapshotResolver moduleInfoRegistry;
  34
  35     @GuardedBy("this")
  36     private ComponentInstance 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 contextFactory, final YangParserFactory factory) {
  45         this.contextFactory = requireNonNull(contextFactory);
  46         moduleInfoRegistry = new ModuleInfoSnapshotResolver("binding-dom-codec", factory);
  47     }
  48
  49     // Invocation from scanner, we may want to ignore this in order to not process partial updates
  50     @Override
  51     void scannerUpdate() {
  52         if (!ignoreScanner) {
  53             synchronized (this) {
  54                 updateService();
  55             }
  56         }
  57     }
  58
  59     @Override
  60     synchronized void scannerShutdown() {
  61         ignoreScanner = true;
  62     }
  63
  64     @Override
  65     synchronized void enableScannerAndUpdate() {
  66         ignoreScanner = false;
  67         updateService();
  68     }
  69
  70     @Override
  71     synchronized void close() {
  72         ignoreScanner = true;
  73         if (currentInstance != null) {
  74             currentInstance.dispose();
  75             currentInstance = null;
  76         }
  77     }
  78
  79     @Override
  80     List<ObjectRegistration<YangModuleInfo>> registerInfos(final List<YangModuleInfo> infos) {
  81         return moduleInfoRegistry.registerModuleInfos(infos);
  82     }
  83
  84     @Holding("this")
  85     private void updateService() {
  86         final ModuleInfoSnapshot newSnapshot;
  87         try {
  88             newSnapshot = moduleInfoRegistry.takeSnapshot();
  89         } catch (NoSuchElementException e) {
  90             LOG.debug("No snapshot available", e);
  91             return;
  92         }
  93         if (newSnapshot.equals(currentSnapshot)) {
  94             LOG.debug("No update to snapshot");
  95             return;
  96         }
  97
  98
  99         final ComponentInstance newInstance = contextFactory.newInstance(
 100             OSGiModuleInfoSnapshotImpl.props(nextGeneration(), newSnapshot));
 101         if (currentInstance != null) {
 102             currentInstance.dispose();
 103         }
 104         currentInstance = newInstance;
 105         currentSnapshot = newSnapshot;
 106     }
 107
 108     @Holding("this")
 109     private long nextGeneration() {
 110         return generation == -1 ? -1 : ++generation;
 111     }
 112 }