binding/mdsal-binding-dom-codec-osgi/src/main/java/org/opendaylight/mdsal/binding/dom/codec/osgi/impl/OSGiBindingDOMCodec.java

   1 /*
   2  * Copyright (c) 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.binding.dom.codec.osgi.impl;
   9
  10 import static com.google.common.base.Verify.verify;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import java.util.Collections;
  14 import java.util.Comparator;
  15 import java.util.IdentityHashMap;
  16 import java.util.Map;
  17 import java.util.Set;
  18 import org.checkerframework.checker.lock.qual.GuardedBy;
  19 import org.eclipse.jdt.annotation.NonNull;
  20 import org.opendaylight.mdsal.binding.dom.codec.spi.BindingDOMCodecFactory;
  21 import org.opendaylight.mdsal.binding.runtime.api.BindingRuntimeContext;
  22 import org.opendaylight.mdsal.binding.runtime.osgi.OSGiBindingRuntimeContext;
  23 import org.osgi.service.component.ComponentFactory;
  24 import org.osgi.service.component.ComponentInstance;
  25 import org.osgi.service.component.annotations.Activate;
  26 import org.osgi.service.component.annotations.Component;
  27 import org.osgi.service.component.annotations.Deactivate;
  28 import org.osgi.service.component.annotations.Reference;
  29 import org.osgi.service.component.annotations.ReferenceCardinality;
  30 import org.osgi.service.component.annotations.ReferencePolicy;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33
  34 @Component(immediate = true)
  35 public final class OSGiBindingDOMCodec {
  36     // TODO: can we get rid of this complexity?
  37     private abstract static class AbstractInstances {
  38
  39         abstract void add(OSGiBindingRuntimeContext runtimeContext);
  40
  41         abstract void remove(OSGiBindingRuntimeContext runtimeContext);
  42
  43         abstract @NonNull AbstractInstances toActive(BindingDOMCodecFactory codecFactory, ComponentFactory factory);
  44
  45         abstract @NonNull AbstractInstances toInactive();
  46     }
  47
  48     private static final class InactiveInstances extends AbstractInstances {
  49         private final Set<OSGiBindingRuntimeContext> instances = Collections.newSetFromMap(new IdentityHashMap<>());
  50
  51         InactiveInstances() {
  52
  53         }
  54
  55         InactiveInstances(final Set<OSGiBindingRuntimeContext> keySet) {
  56             instances.addAll(keySet);
  57         }
  58
  59         @Override
  60         void add(final OSGiBindingRuntimeContext runtimeContext) {
  61             verify(instances.add(runtimeContext), "Duplicate instance %s?!", runtimeContext);
  62         }
  63
  64         @Override
  65         void remove(final OSGiBindingRuntimeContext runtimeContext) {
  66             instances.remove(runtimeContext);
  67         }
  68
  69         @Override
  70         AbstractInstances toActive(final BindingDOMCodecFactory codecFactory, final ComponentFactory factory) {
  71             final ActiveInstances active = new ActiveInstances(codecFactory, factory);
  72             instances.stream()
  73                 .sorted(Comparator.comparing(OSGiBindingRuntimeContext::getGeneration).reversed())
  74                 .forEach(active::add);
  75             return active;
  76         }
  77
  78         @Override
  79         AbstractInstances toInactive() {
  80             throw new IllegalStateException("Attempted to deactivate inactive instances");
  81         }
  82     }
  83
  84     private static final class ActiveInstances extends AbstractInstances {
  85         private final Map<OSGiBindingRuntimeContext, ComponentInstance> instances = new IdentityHashMap<>();
  86         private final BindingDOMCodecFactory codecFactory;
  87         private final ComponentFactory factory;
  88
  89         ActiveInstances(final BindingDOMCodecFactory codecFactory, final ComponentFactory factory) {
  90             this.codecFactory = requireNonNull(codecFactory);
  91             this.factory = requireNonNull(factory);
  92         }
  93
  94         @Override
  95         void add(final OSGiBindingRuntimeContext runtimeContext) {
  96             final BindingRuntimeContext context = runtimeContext.getService();
  97
  98             instances.put(runtimeContext, factory.newInstance(OSGiBindingDOMCodecServicesImpl.props(
  99                 runtimeContext.getGeneration(), runtimeContext.getServiceRanking(),
 100                 codecFactory.createBindingDOMCodec(context))));
 101         }
 102
 103         @Override
 104         void remove(final OSGiBindingRuntimeContext runtimeContext) {
 105             final ComponentInstance instance = instances.remove(runtimeContext);
 106             if (instance != null) {
 107                 instance.dispose();
 108             } else {
 109                 LOG.warn("Instance for generation {} not found", runtimeContext.getGeneration());
 110             }
 111         }
 112
 113         @Override
 114         AbstractInstances toActive(final BindingDOMCodecFactory ignoreCodecFactory,
 115                 final ComponentFactory ignoreFactory) {
 116             throw new IllegalStateException("Attempted to activate active instances");
 117         }
 118
 119         @Override
 120         AbstractInstances toInactive() {
 121             instances.values().forEach(ComponentInstance::dispose);
 122             return new InactiveInstances(instances.keySet());
 123         }
 124
 125     }
 126
 127     private static final Logger LOG = LoggerFactory.getLogger(OSGiBindingDOMCodec.class);
 128
 129     @Reference
 130     BindingDOMCodecFactory codecFactory = null;
 131
 132     @Reference(target = "(component.factory=" + OSGiBindingDOMCodecServicesImpl.FACTORY_NAME + ")")
 133     ComponentFactory contextFactory = null;
 134
 135     @GuardedBy("this")
 136     private AbstractInstances instances = new InactiveInstances();
 137
 138     @Reference(cardinality = ReferenceCardinality.MULTIPLE, policy = ReferencePolicy.DYNAMIC)
 139     synchronized void addModuleInfoSnapshot(final OSGiBindingRuntimeContext runtimeContext) {
 140         instances.add(runtimeContext);
 141     }
 142
 143     synchronized void removeModuleInfoSnapshot(final OSGiBindingRuntimeContext runtimeContext) {
 144         instances.remove(runtimeContext);
 145     }
 146
 147     @Activate
 148     synchronized void activate() {
 149         LOG.info("Binding/DOM Codec activating");
 150         instances = instances.toActive(codecFactory, contextFactory);
 151         LOG.info("Binding/DOM Codec activated");
 152     }
 153
 154     @Deactivate
 155     synchronized void deactivate() {
 156         LOG.info("Binding/DOM Codec deactivating");
 157         instances = instances.toInactive();
 158         LOG.info("Binding/DOM Codec deactivated");
 159     }
 160 }