2 * Copyright (c) 2020 PANTHEON.tech, s.r.o. and others. All rights reserved.
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
8 package org.opendaylight.mdsal.dom.spi.query;
10 import static com.google.common.base.Preconditions.checkArgument;
11 import static java.util.Objects.requireNonNull;
13 import java.util.AbstractMap.SimpleImmutableEntry;
14 import java.util.ArrayDeque;
15 import java.util.ArrayList;
16 import java.util.Iterator;
17 import java.util.List;
18 import java.util.Map.Entry;
19 import java.util.Optional;
20 import org.eclipse.jdt.annotation.NonNullByDefault;
21 import org.opendaylight.mdsal.dom.api.query.DOMQuery;
22 import org.opendaylight.mdsal.dom.api.query.DOMQueryPredicate;
23 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
26 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
27 import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
28 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
29 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodes;
32 final class LazyDOMQueryResultIterator implements Iterator<Entry<YangInstanceIdentifier, NormalizedNode<?, ?>>> {
34 private final ArrayDeque<NormalizedNode<?, ?>> currentData = new ArrayDeque<>();
35 // Absolute path from root of current data item
36 private final ArrayDeque<PathArgument> currentPath;
37 // Steps remaining in the select part of the query
38 private final ArrayDeque<PathArgument> selectSteps;
39 // The query which needs to be executed
40 private final DOMQuery query;
42 // FIXME: MDSAL-610: this needs to be eliminated
43 private final Iterator<Entry<YangInstanceIdentifier, NormalizedNode<?, ?>>> iter;
45 LazyDOMQueryResultIterator(final DOMQuery query, final NormalizedNode<?, ?> queryRoot) {
46 this.query = requireNonNull(query);
47 currentPath = new ArrayDeque<>(query.getRoot().getPathArguments());
48 selectSteps = new ArrayDeque<>(query.getSelect().getPathArguments());
49 currentData.push(queryRoot);
51 // FIXME: MDSAL-610: this is a recursive algo, filling provided list. Turn it around into a state mutator.
52 final List<Entry<YangInstanceIdentifier, NormalizedNode<?,?>>> result = new ArrayList<>();
54 this.iter = result.iterator();
60 public boolean hasNext() {
61 return iter.hasNext();
65 public Entry<YangInstanceIdentifier, NormalizedNode<?, ?>> next() {
69 private void evalPath(final List<Entry<YangInstanceIdentifier, NormalizedNode<?,?>>> result) {
70 final NormalizedNode<?, ?> data = currentData.pop();
71 final PathArgument next = selectSteps.poll();
73 if (matches(data, query)) {
74 result.add(new SimpleImmutableEntry<>(YangInstanceIdentifier.create(currentPath), data));
79 if (data instanceof MapNode && next instanceof NodeIdentifier) {
80 checkArgument(data.getIdentifier().equals(next), "Unexpected step %s", next);
81 for (MapEntryNode child : ((MapNode) data).getValue()) {
82 evalChild(result, child);
85 NormalizedNodes.getDirectChild(data, next).ifPresent(child -> evalChild(result, child));
87 selectSteps.push(next);
90 private void evalChild(final List<Entry<YangInstanceIdentifier, NormalizedNode<?,?>>> result,
91 final NormalizedNode<?, ?> child) {
92 currentPath.addLast(child.getIdentifier());
93 currentData.push(child);
95 currentPath.removeLast();
98 static boolean matches(final NormalizedNode<?, ?> data, final DOMQuery query) {
99 for (DOMQueryPredicate pred : query.getPredicates()) {
100 // Okay, now we need to deal with predicates, but do it in a smart fashion, so we do not end up iterating
101 // all over the place. Typically we will be matching just a leaf.
102 final YangInstanceIdentifier path = pred.getPath();
103 final Optional<NormalizedNode<?, ?>> node;
104 if (path.coerceParent().isEmpty()) {
105 node = NormalizedNodes.getDirectChild(data, path.getLastPathArgument());
107 node = NormalizedNodes.findNode(data, path);
110 if (!pred.test(node.orElse(null))) {