Rework binding component instantiation

[mdsal.git] / dom / mdsal-dom-schema-osgi / src / main / java / org / opendaylight / mdsal / dom / schema / osgi / impl / YangModuleInfoRegistry.java

diff --git a/dom/mdsal-dom-schema-osgi/src/main/java/org/opendaylight/mdsal/dom/schema/osgi/impl/YangModuleInfoRegistry.java b/dom/mdsal-dom-schema-osgi/src/main/java/org/opendaylight/mdsal/dom/schema/osgi/impl/YangModuleInfoRegistry.java
new file mode 100644 (file)
index 0000000..de1b4ad
--- /dev/null
+++ b/dom/mdsal-dom-schema-osgi/src/main/java/org/opendaylight/mdsal/dom/schema/osgi/impl/YangModuleInfoRegistry.java
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2017, 2020 PANTHEON.tech, s.r.o. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.mdsal.dom.schema.osgi.impl;
+
+import static java.util.Objects.requireNonNull;
+
+import java.util.List;
+import java.util.NoSuchElementException;
+import org.checkerframework.checker.lock.qual.GuardedBy;
+import org.checkerframework.checker.lock.qual.Holding;
+import org.opendaylight.binding.runtime.api.ModuleInfoSnapshot;
+import org.opendaylight.binding.runtime.spi.ModuleInfoSnapshotBuilder;
+import org.opendaylight.yangtools.concepts.ObjectRegistration;
+import org.opendaylight.yangtools.yang.binding.YangModuleInfo;
+import org.opendaylight.yangtools.yang.model.parser.api.YangParserFactory;
+import org.osgi.service.component.ComponentFactory;
+import org.osgi.service.component.ComponentInstance;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Update SchemaContext service in Service Registry each time new YangModuleInfo is added or removed.
+ */
+final class YangModuleInfoRegistry {
+    private static final Logger LOG = LoggerFactory.getLogger(YangModuleInfoRegistry.class);
+
+    private final ComponentFactory contextFactory;
+    private final ModuleInfoSnapshotBuilder moduleInfoRegistry;
+
+    @GuardedBy("this")
+    private ComponentInstance currentInstance;
+    @GuardedBy("this")
+    private ModuleInfoSnapshot currentSnapshot;
+    @GuardedBy("this")
+    private int generation;
+
+    private volatile boolean ignoreScanner = true;
+
+    YangModuleInfoRegistry(final ComponentFactory contextFactory, final YangParserFactory factory) {
+        this.contextFactory = requireNonNull(contextFactory);
+        moduleInfoRegistry = new ModuleInfoSnapshotBuilder("binding-dom-codec", factory);
+    }
+
+    // Invocation from scanner, we may want to ignore this in order to not process partial updates
+    void scannerUpdate() {
+        if (!ignoreScanner) {
+            synchronized (this) {
+                updateService();
+            }
+        }
+    }
+
+    synchronized void scannerShutdown() {
+        ignoreScanner = true;
+    }
+
+    synchronized void enableScannerAndUpdate() {
+        ignoreScanner = false;
+        updateService();
+    }
+
+    synchronized void close() {
+        ignoreScanner = true;
+        if (currentInstance != null) {
+            currentInstance.dispose();
+            currentInstance = null;
+        }
+    }
+
+    List<ObjectRegistration<YangModuleInfo>> registerInfos(final List<YangModuleInfo> infos) {
+        return moduleInfoRegistry.registerModuleInfos(infos);
+    }
+
+    @Holding("this")
+    private void updateService() {
+        final ModuleInfoSnapshot newSnapshot;
+        try {
+            newSnapshot = moduleInfoRegistry.build();
+        } catch (NoSuchElementException e) {
+            LOG.debug("No snapshot available", e);
+            return;
+        }
+        if (newSnapshot.equals(currentSnapshot)) {
+            LOG.debug("No update to snapshot");
+            return;
+        }
+
+
+        final ComponentInstance newInstance = contextFactory.newInstance(
+            OSGiEffectiveModelImpl.props(nextGeneration(), newSnapshot));
+        if (currentInstance != null) {
+            currentInstance.dispose();
+        }
+        currentInstance = newInstance;
+        currentSnapshot = newSnapshot;
+    }
+
+    @Holding("this")
+    private long nextGeneration() {
+        return generation == -1 ? -1 : ++generation;
+    }
+}