yang/yang-data-api/src/main/java/org/opendaylight/yangtools/yang/data/api/schema/tree/DataTreeCandidateNodes.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. 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.yangtools.yang.data.api.schema.tree;
   9
  10 import com.google.common.annotations.Beta;
  11 import com.google.common.base.Preconditions;
  12 import java.util.Collection;
  13 import java.util.Iterator;
  14 import javax.annotation.Nonnull;
  15 import javax.annotation.Nullable;
  16 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  17 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  18 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  19
  20 @Beta
  21 public final class DataTreeCandidateNodes {
  22     private DataTreeCandidateNodes() {
  23         throw new UnsupportedOperationException();
  24     }
  25
  26     /**
  27      * Return an empty {@link DataTreeCandidateNode} identified by specified {@link PathArgument}.
  28      * @param identifier Node identifier
  29      * @return An empty DataTreeCandidateNode
  30      */
  31     public static DataTreeCandidateNode empty(final PathArgument identifier) {
  32         return new EmptyDataTreeCandidateNode(identifier);
  33     }
  34
  35     public static DataTreeCandidateNode fromNormalizedNode(final NormalizedNode<?, ?> node) {
  36         return new NormalizedNodeDataTreeCandidateNode(node);
  37     }
  38
  39     /**
  40      * Applies the {@code node} to the {@code cursor}, note that if the top node of (@code node} is RootNode
  41      * you need to use {@link #applyRootedNodeToCursor(DataTreeModificationCursor, YangInstanceIdentifier,
  42      * DataTreeCandidateNode) applyRootedNodeToCursor} method that works with rooted node candidates.
  43      *
  44      * @param cursor cursor from the modification we want to apply the {@code node} to
  45      * @param node candidate tree to apply
  46      */
  47     public static void applyToCursor(final DataTreeModificationCursor cursor, final DataTreeCandidateNode node) {
  48         switch (node.getModificationType()) {
  49             case DELETE:
  50                 cursor.delete(node.getIdentifier());
  51                 break;
  52             case SUBTREE_MODIFIED:
  53                 cursor.enter(node.getIdentifier());
  54                 AbstractNodeIterator iterator = new ExitingNodeIterator(null, node.getChildNodes().iterator());
  55                 do {
  56                     iterator = iterator.next(cursor);
  57                 } while (iterator != null);
  58                 break;
  59             case UNMODIFIED:
  60                 // No-op
  61                 break;
  62             case WRITE:
  63                 cursor.write(node.getIdentifier(), node.getDataAfter().get());
  64                 break;
  65             default:
  66                 throw new IllegalArgumentException("Unsupported modification " + node.getModificationType());
  67         }
  68     }
  69
  70     /**
  71      * Applies the {@code node} that is rooted(doesn't have an identifier) in tree A to tree B's {@code cursor}
  72      * at location specified by {@code rootPath}.
  73      *
  74      * @param cursor cursor from the modification we want to apply the {@code node} to
  75      * @param rootPath path in the {@code cursor}'s tree we want to apply to candidate to
  76      * @param node candidate tree to apply
  77      */
  78     public static void applyRootedNodeToCursor(final DataTreeModificationCursor cursor,
  79             final YangInstanceIdentifier rootPath, final DataTreeCandidateNode node) {
  80         switch (node.getModificationType()) {
  81             case DELETE:
  82                 cursor.delete(rootPath.getLastPathArgument());
  83                 break;
  84             case SUBTREE_MODIFIED:
  85                 cursor.enter(rootPath.getLastPathArgument());
  86                 AbstractNodeIterator iterator = new ExitingNodeIterator(null, node.getChildNodes().iterator());
  87                 do {
  88                     iterator = iterator.next(cursor);
  89                 } while (iterator != null);
  90                 break;
  91             case UNMODIFIED:
  92                 // No-op
  93                 break;
  94             case WRITE:
  95                 cursor.write(rootPath.getLastPathArgument(), node.getDataAfter().get());
  96                 break;
  97             default:
  98                 throw new IllegalArgumentException("Unsupported modification " + node.getModificationType());
  99         }
 100     }
 101
 102     public static void applyRootToCursor(final DataTreeModificationCursor cursor, final DataTreeCandidateNode node) {
 103         switch (node.getModificationType()) {
 104             case DELETE:
 105                 throw new IllegalArgumentException("Can not delete root.");
 106             case WRITE:
 107             case SUBTREE_MODIFIED:
 108                 AbstractNodeIterator iterator = new RootNonExitingIterator(node.getChildNodes().iterator());
 109                 do {
 110                     iterator = iterator.next(cursor);
 111                 } while (iterator != null);
 112                 break;
 113             case UNMODIFIED:
 114                 // No-op
 115                 break;
 116             default:
 117                 throw new IllegalArgumentException("Unsupported modification " + node.getModificationType());
 118         }
 119     }
 120
 121     private abstract static class AbstractNodeIterator {
 122         private final Iterator<DataTreeCandidateNode> iterator;
 123
 124         AbstractNodeIterator(final Iterator<DataTreeCandidateNode> iterator) {
 125             this.iterator = Preconditions.checkNotNull(iterator);
 126         }
 127
 128         AbstractNodeIterator next(final DataTreeModificationCursor cursor) {
 129             while (iterator.hasNext()) {
 130                 final DataTreeCandidateNode node = iterator.next();
 131                 switch (node.getModificationType()) {
 132                     case DELETE:
 133                         cursor.delete(node.getIdentifier());
 134                         break;
 135                     case APPEARED:
 136                     case DISAPPEARED:
 137                     case SUBTREE_MODIFIED:
 138                         final Collection<DataTreeCandidateNode> children = node.getChildNodes();
 139                         if (!children.isEmpty()) {
 140                             cursor.enter(node.getIdentifier());
 141                             return new ExitingNodeIterator(this, children.iterator());
 142                         }
 143                         break;
 144                     case UNMODIFIED:
 145                         // No-op
 146                         break;
 147                     case WRITE:
 148                         cursor.write(node.getIdentifier(), node.getDataAfter().get());
 149                         break;
 150                     default:
 151                         throw new IllegalArgumentException("Unsupported modification " + node.getModificationType());
 152                 }
 153             }
 154             exitNode(cursor);
 155             return getParent();
 156         }
 157
 158         protected abstract @Nullable AbstractNodeIterator getParent();
 159
 160         protected abstract void exitNode(DataTreeModificationCursor cursor);
 161     }
 162
 163     private static final class RootNonExitingIterator extends AbstractNodeIterator {
 164
 165         protected RootNonExitingIterator(@Nonnull final Iterator<DataTreeCandidateNode> iterator) {
 166             super(iterator);
 167         }
 168
 169         @Override
 170         protected void exitNode(final DataTreeModificationCursor cursor) {
 171             // Intentional noop.
 172         }
 173
 174         @Override
 175         protected AbstractNodeIterator getParent() {
 176             return null;
 177         }
 178     }
 179
 180     private static final class ExitingNodeIterator extends AbstractNodeIterator {
 181
 182         private final AbstractNodeIterator parent;
 183
 184         ExitingNodeIterator(@Nullable final AbstractNodeIterator parent,
 185                 @Nonnull final Iterator<DataTreeCandidateNode> iterator) {
 186             super(iterator);
 187             this.parent = parent;
 188         }
 189
 190         @Override
 191         protected AbstractNodeIterator getParent() {
 192             return parent;
 193         }
 194
 195         @Override
 196         protected void exitNode(final DataTreeModificationCursor cursor) {
 197             cursor.exit();
 198         }
 199     }
 200 }