Rework binding component instantiation
[mdsal.git] / dom / mdsal-dom-schema-osgi / src / main / java / org / opendaylight / mdsal / dom / schema / osgi / impl / OSGiDOMSchemaService.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.concurrent.CopyOnWriteArrayList;
14 import org.eclipse.jdt.annotation.NonNull;
15 import org.opendaylight.mdsal.dom.api.DOMSchemaService;
16 import org.opendaylight.mdsal.dom.schema.osgi.OSGiModuleInfoSnapshot;
17 import org.opendaylight.mdsal.dom.spi.AbstractDOMSchemaService;
18 import org.opendaylight.yangtools.concepts.ListenerRegistration;
19 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
20 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
21 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
22 import org.osgi.service.component.ComponentFactory;
23 import org.osgi.service.component.ComponentInstance;
24 import org.osgi.service.component.annotations.Activate;
25 import org.osgi.service.component.annotations.Component;
26 import org.osgi.service.component.annotations.Deactivate;
27 import org.osgi.service.component.annotations.FieldOption;
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.osgi.service.component.annotations.ReferencePolicyOption;
32 import org.slf4j.Logger;
33 import org.slf4j.LoggerFactory;
34
35 /**
36  * OSGi Service Registry-backed implementation of {@link DOMSchemaService}.
37  */
38 @Component(service = DOMSchemaService.class, immediate = true)
39 public final class OSGiDOMSchemaService extends AbstractDOMSchemaService {
40     private static final Logger LOG = LoggerFactory.getLogger(OSGiDOMSchemaService.class);
41
42     @Reference(target = "(component.factory=" + SchemaSchemaContextListenerImpl.FACTORY_NAME + ")")
43     ComponentFactory listenerFactory = null;
44
45     private final List<SchemaContextListener> listeners = new CopyOnWriteArrayList<>();
46
47     private volatile OSGiModuleInfoSnapshot currentContext;
48
49     @Override
50     public EffectiveModelContext getGlobalContext() {
51         return currentContext.getEffectiveModelContext();
52     }
53
54     @Override
55     public ListenerRegistration<SchemaContextListener> registerSchemaContextListener(
56             final SchemaContextListener listener) {
57         return registerListener(requireNonNull(listener));
58     }
59
60     @Reference(fieldOption = FieldOption.REPLACE)
61     void bindContext(final OSGiModuleInfoSnapshot newContext) {
62         final EffectiveModelContext ctx = newContext.getEffectiveModelContext();
63         LOG.trace("Updating context to {}", ctx);
64         currentContext = newContext;
65         listeners.forEach(listener -> notifyListener(ctx, listener));
66     }
67
68     @Reference(cardinality = ReferenceCardinality.MULTIPLE, policy = ReferencePolicy.DYNAMIC,
69             policyOption = ReferencePolicyOption.GREEDY)
70     void addListener(final SchemaContextListener listener) {
71         LOG.trace("Adding listener {}", listener);
72         listeners.add(listener);
73         listener.onGlobalContextUpdated(getGlobalContext());
74     }
75
76     void removeListener(final SchemaContextListener listener) {
77         LOG.trace("Removing listener {}", listener);
78         listeners.remove(listener);
79     }
80
81     @Activate
82     @SuppressWarnings("static-method")
83     void activate() {
84         LOG.info("DOM Schema services activated");
85     }
86
87     @Deactivate
88     @SuppressWarnings("static-method")
89     void deactivate() {
90         LOG.info("DOM Schema services deactivated");
91     }
92
93     private @NonNull ListenerRegistration<SchemaContextListener> registerListener(
94             final @NonNull SchemaContextListener listener) {
95         final ComponentInstance reg = listenerFactory.newInstance(SchemaSchemaContextListenerImpl.props(listener));
96         return new ListenerRegistration<>() {
97             @Override
98             public SchemaContextListener getInstance() {
99                 return listener;
100             }
101
102             @Override
103             public void close() {
104                 reg.dispose();
105             }
106         };
107     }
108
109     @SuppressWarnings("checkstyle:illegalCatch")
110     private static void notifyListener(final SchemaContext context, final SchemaContextListener listener) {
111         try {
112             listener.onGlobalContextUpdated(context);
113         } catch (RuntimeException e) {
114             LOG.warn("Failed to notify listener {}", listener, e);
115         }
116     }
117 }