Java tutorial
/* * Copyright (c) 2014 Cisco Systems, Inc. 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.onos.yangtools.yang.data.impl.codec; import com.google.common.annotations.Beta; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.base.Predicate; import com.google.common.collect.Iterables; import java.io.IOException; import java.util.ArrayDeque; import java.util.Deque; import java.util.HashSet; import org.onos.yangtools.yang.common.QName; import org.onos.yangtools.yang.data.api.YangInstanceIdentifier.AugmentationIdentifier; import org.onos.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier; import org.onos.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument; import org.onos.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter; import org.onos.yangtools.yang.data.impl.schema.SchemaUtils; import org.onos.yangtools.yang.model.api.AnyXmlSchemaNode; import org.onos.yangtools.yang.model.api.AugmentationSchema; import org.onos.yangtools.yang.model.api.AugmentationTarget; import org.onos.yangtools.yang.model.api.ChoiceCaseNode; import org.onos.yangtools.yang.model.api.ChoiceSchemaNode; import org.onos.yangtools.yang.model.api.ContainerSchemaNode; import org.onos.yangtools.yang.model.api.DataNodeContainer; import org.onos.yangtools.yang.model.api.DataSchemaNode; import org.onos.yangtools.yang.model.api.GroupingDefinition; import org.onos.yangtools.yang.model.api.LeafListSchemaNode; import org.onos.yangtools.yang.model.api.LeafSchemaNode; import org.onos.yangtools.yang.model.api.ListSchemaNode; import org.onos.yangtools.yang.model.api.NotificationDefinition; import org.onos.yangtools.yang.model.api.RpcDefinition; import org.onos.yangtools.yang.model.api.SchemaContext; import org.onos.yangtools.yang.model.api.SchemaNode; import org.onos.yangtools.yang.model.api.SchemaPath; import org.onos.yangtools.yang.model.util.EffectiveAugmentationSchema; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Utility class for tracking the underlying state of the underlying * schema node. */ @Beta public final class SchemaTracker { private static final Logger LOG = LoggerFactory.getLogger(SchemaTracker.class); private final Deque<Object> schemaStack = new ArrayDeque<>(); private final DataNodeContainer root; private SchemaTracker(final SchemaContext context, final SchemaPath path) { SchemaNode current = Preconditions.checkNotNull(context); for (final QName qname : path.getPathFromRoot()) { SchemaNode child; if (current instanceof DataNodeContainer) { child = ((DataNodeContainer) current).getDataChildByName(qname); if (child == null && current instanceof SchemaContext) { child = tryFindGroupings((SchemaContext) current, qname).orNull(); } if (child == null && current instanceof SchemaContext) { child = tryFindNotification((SchemaContext) current, qname) .or(tryFindRpc(((SchemaContext) current), qname)).orNull(); } } else if (current instanceof ChoiceSchemaNode) { child = ((ChoiceSchemaNode) current).getCaseNodeByName(qname); } else if (current instanceof RpcDefinition) { switch (qname.getLocalName()) { case "input": child = ((RpcDefinition) current).getInput(); break; case "output": child = ((RpcDefinition) current).getOutput(); break; default: child = null; break; } } else { throw new IllegalArgumentException( String.format("Schema node %s does not allow children.", current)); } current = child; } Preconditions.checkArgument(current instanceof DataNodeContainer, "Schema path must point to container or list or an rpc input/output. Supplied path %s pointed to: %s", path, current); root = (DataNodeContainer) current; } private Optional<SchemaNode> tryFindGroupings(final SchemaContext ctx, final QName qname) { return Optional .<SchemaNode>fromNullable(Iterables.find(ctx.getGroupings(), new SchemaNodePredicate(qname), null)); } private Optional<SchemaNode> tryFindRpc(final SchemaContext ctx, final QName qname) { return Optional.<SchemaNode>fromNullable( Iterables.find(ctx.getOperations(), new SchemaNodePredicate(qname), null)); } private Optional<SchemaNode> tryFindNotification(final SchemaContext ctx, final QName qname) { return Optional.<SchemaNode>fromNullable( Iterables.find(ctx.getNotifications(), new SchemaNodePredicate(qname), null)); } /** * Create a new writer with the specified context as its root. * * @param context Associated {@link SchemaContext}. * @return A new {@link NormalizedNodeStreamWriter} */ public static SchemaTracker create(final SchemaContext context) { return create(context, SchemaPath.ROOT); } /** * Create a new writer with the specified context and rooted in the specified schema path * * @param context Associated {@link SchemaContext} * @param path schema path * * @return A new {@link NormalizedNodeStreamWriter} */ public static SchemaTracker create(final SchemaContext context, final SchemaPath path) { return new SchemaTracker(context, path); } public Object getParent() { if (schemaStack.isEmpty()) { return root; } return schemaStack.peek(); } private SchemaNode getSchema(final PathArgument name) { final Object parent = getParent(); SchemaNode schema = null; final QName qname = name.getNodeType(); if (parent instanceof DataNodeContainer) { schema = ((DataNodeContainer) parent).getDataChildByName(qname); if (schema == null && parent instanceof GroupingDefinition) { schema = ((GroupingDefinition) parent); } if (schema == null && parent instanceof NotificationDefinition) { schema = ((NotificationDefinition) parent); } } else if (parent instanceof ChoiceSchemaNode) { schema = findChildInCases((ChoiceSchemaNode) parent, qname); } else { throw new IllegalStateException("Unsupported schema type " + parent.getClass() + " on stack."); } Preconditions.checkArgument(schema != null, "Could not find schema for node %s in %s", qname, parent); return schema; } private SchemaNode findChildInCases(final ChoiceSchemaNode parent, final QName qname) { DataSchemaNode schema = null; for (final ChoiceCaseNode caze : parent.getCases()) { final DataSchemaNode potential = caze.getDataChildByName(qname); if (potential != null) { schema = potential; break; } } return schema; } private SchemaNode findCaseByChild(final ChoiceSchemaNode parent, final QName qname) { DataSchemaNode schema = null; for (final ChoiceCaseNode caze : parent.getCases()) { final DataSchemaNode potential = caze.getDataChildByName(qname); if (potential != null) { schema = caze; break; } } return schema; } public void startList(final PathArgument name) { final SchemaNode schema = getSchema(name); Preconditions.checkArgument(schema instanceof ListSchemaNode, "Node %s is not a list", schema.getPath()); schemaStack.push(schema); } public void startListItem(final PathArgument name) throws IOException { final Object schema = getParent(); Preconditions.checkArgument(schema instanceof ListSchemaNode, "List item is not appropriate"); schemaStack.push(schema); } public LeafSchemaNode leafNode(final NodeIdentifier name) throws IOException { final SchemaNode schema = getSchema(name); Preconditions.checkArgument(schema instanceof LeafSchemaNode, "Node %s is not a leaf", schema.getPath()); return (LeafSchemaNode) schema; } public LeafListSchemaNode startLeafSet(final NodeIdentifier name) { final SchemaNode schema = getSchema(name); Preconditions.checkArgument(schema instanceof LeafListSchemaNode, "Node %s is not a leaf-list", schema.getPath()); schemaStack.push(schema); return (LeafListSchemaNode) schema; } public LeafListSchemaNode leafSetEntryNode() { final Object parent = getParent(); Preconditions.checkArgument(parent instanceof LeafListSchemaNode, "Not currently in a leaf-list"); return (LeafListSchemaNode) parent; } public ChoiceSchemaNode startChoiceNode(final NodeIdentifier name) { LOG.debug("Enter choice {}", name); final SchemaNode schema = getSchema(name); Preconditions.checkArgument(schema instanceof ChoiceSchemaNode, "Node %s is not a choice", schema.getPath()); schemaStack.push(schema); return (ChoiceSchemaNode) schema; } public SchemaNode startContainerNode(final NodeIdentifier name) { LOG.debug("Enter container {}", name); final SchemaNode schema = getSchema(name); boolean isAllowed = schema instanceof ContainerSchemaNode; isAllowed |= schema instanceof NotificationDefinition; Preconditions.checkArgument(isAllowed, "Node %s is not a container nor a notification", schema.getPath()); schemaStack.push(schema); return schema; } public AugmentationSchema startAugmentationNode(final AugmentationIdentifier identifier) { LOG.debug("Enter augmentation {}", identifier); Object parent = getParent(); Preconditions.checkArgument(parent instanceof AugmentationTarget, "Augmentation not allowed under %s", parent); if (parent instanceof ChoiceSchemaNode) { final QName name = Iterables.get(identifier.getPossibleChildNames(), 0); parent = findCaseByChild((ChoiceSchemaNode) parent, name); } Preconditions.checkArgument(parent instanceof DataNodeContainer, "Augmentation allowed only in DataNodeContainer", parent); final AugmentationSchema schema = SchemaUtils.findSchemaForAugment((AugmentationTarget) parent, identifier.getPossibleChildNames()); final HashSet<DataSchemaNode> realChildSchemas = new HashSet<>(); for (final DataSchemaNode child : schema.getChildNodes()) { realChildSchemas.add(((DataNodeContainer) parent).getDataChildByName(child.getQName())); } final AugmentationSchema resolvedSchema = new EffectiveAugmentationSchema(schema, realChildSchemas); schemaStack.push(resolvedSchema); return resolvedSchema; } public AnyXmlSchemaNode anyxmlNode(final NodeIdentifier name) { final SchemaNode schema = getSchema(name); Preconditions.checkArgument(schema instanceof AnyXmlSchemaNode, "Node %s is not anyxml", schema.getPath()); return (AnyXmlSchemaNode) schema; } public Object endNode() { return schemaStack.pop(); } private static final class SchemaNodePredicate implements Predicate<SchemaNode> { private final QName qname; public SchemaNodePredicate(final QName qname) { this.qname = qname; } @Override public boolean apply(final SchemaNode input) { return input.getQName().equals(qname); } } }