restconf/restconf-nb/src/main/java/org/opendaylight/restconf/server/mdsal/streams/dtcl/DataTreeCandidateSerializer.java

   1 /*
   2  * Copyright (c) 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.restconf.server.mdsal.streams.dtcl;
   9
  10 import static com.google.common.base.Verify.verifyNotNull;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import com.google.common.base.VerifyException;
  14 import java.util.ArrayDeque;
  15 import java.util.ArrayList;
  16 import java.util.Collection;
  17 import java.util.Comparator;
  18 import java.util.Deque;
  19 import org.eclipse.jdt.annotation.NonNull;
  20 import org.eclipse.jdt.annotation.Nullable;
  21 import org.opendaylight.restconf.server.spi.TextParameters;
  22 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.remote.rev140114.data.changed.notification.DataChangeEvent;
  23 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.remote.rev140114.data.changed.notification.DataChangeEvent.Operation;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.remote.rev140114.data.changed.notification.data.change.event.Data;
  25 import org.opendaylight.yangtools.yang.common.QName;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  28 import org.opendaylight.yangtools.yang.data.api.schema.ChoiceNode;
  29 import org.opendaylight.yangtools.yang.data.api.schema.LeafNode;
  30 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  32 import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
  33 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  34 import org.opendaylight.yangtools.yang.data.spi.node.ImmutableNodes;
  35 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidate;
  36 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidateNode;
  37 import org.opendaylight.yangtools.yang.data.util.DataSchemaContext;
  38 import org.opendaylight.yangtools.yang.data.util.DataSchemaContextTree;
  39 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  40 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack;
  41 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack.Inference;
  42 import org.slf4j.Logger;
  43 import org.slf4j.LoggerFactory;
  44
  45 abstract class DataTreeCandidateSerializer<T extends Exception> {
  46     private static final Logger LOG = LoggerFactory.getLogger(DataTreeCandidateSerializer.class);
  47     static final @NonNull QName PATH_QNAME = QName.create(DataChangeEvent.QNAME, "path").intern();
  48     static final @NonNull NodeIdentifier PATH_NID = NodeIdentifier.create(PATH_QNAME);
  49     static final @NonNull QName OPERATION_QNAME = QName.create(DataChangeEvent.QNAME, "operation").intern();
  50     static final @NonNull NodeIdentifier OPERATION_NID = NodeIdentifier.create(OPERATION_QNAME);
  51     static final @NonNull String DATA_NAME = Data.QNAME.getLocalName();
  52
  53     private final EffectiveModelContext context;
  54
  55     DataTreeCandidateSerializer(final EffectiveModelContext context) {
  56         this.context = requireNonNull(context);
  57     }
  58
  59     final boolean serialize(final DataTreeCandidate candidate, final TextParameters params) throws T {
  60         final var skipData = params.skipData();
  61         final var changedLeafNodesOnly = params.changedLeafNodesOnly();
  62         if (changedLeafNodesOnly || params.leafNodesOnly()) {
  63             return serializeLeafNodesOnly(mutableRootPath(candidate), candidate.getRootNode(), skipData,
  64                 changedLeafNodesOnly);
  65         }
  66         if (params.childNodesOnly()) {
  67             return serializeChildNodesOnly(mutableRootPath(candidate), candidate.getRootNode(), skipData);
  68         }
  69
  70         serializeData(candidate.getRootPath().getPathArguments(), candidate.getRootNode(), skipData);
  71         return true;
  72     }
  73
  74     private static Deque<PathArgument> mutableRootPath(final DataTreeCandidate candidate) {
  75         final var ret = new ArrayDeque<PathArgument>();
  76         ret.addAll(candidate.getRootPath().getPathArguments());
  77         return ret;
  78     }
  79
  80     final boolean serializeLeafNodesOnly(final Deque<PathArgument> path, final DataTreeCandidateNode candidate,
  81             final boolean skipData, final boolean changedLeafNodesOnly) throws T {
  82         final var node = switch (candidate.modificationType()) {
  83             case SUBTREE_MODIFIED, APPEARED -> candidate.getDataAfter();
  84             case DELETE, DISAPPEARED -> candidate.getDataBefore();
  85             case WRITE -> changedLeafNodesOnly && isNotUpdate(candidate) ? null : candidate.getDataAfter();
  86             case UNMODIFIED -> {
  87                 // no reason to do anything with an unmodified node
  88                 LOG.debug("DataTreeCandidate for a notification is unmodified, not serializing leaves. Candidate: {}",
  89                         candidate);
  90                 yield null;
  91             }
  92         };
  93
  94         if (node == null) {
  95             return false;
  96         }
  97         if (node instanceof LeafNode || node instanceof LeafSetNode) {
  98             serializeData(path, candidate, skipData);
  99             return true;
 100         }
 101
 102         // Retain a modicum of sanity here: children may come from different namespaces. Report children from the same
 103         // namespace first, holding others back. Once that is done, sort the remaining children by their PathArgument
 104         // and report them in that order.
 105         final var myNamespace = node.name().getNodeType().getModule();
 106         final var heldBack = new ArrayList<DataTreeCandidateNode>();
 107         boolean ret = false;
 108         for (var childNode : candidate.childNodes()) {
 109             final var childName = childNode.name();
 110             if (myNamespace.equals(childName.getNodeType().getModule())) {
 111                 ret |= serializeChild(path, childNode, skipData, changedLeafNodesOnly);
 112             } else {
 113                 heldBack.add(childNode);
 114             }
 115         }
 116         if (!heldBack.isEmpty()) {
 117             // This is not exactly nice, as we really should be using schema definition order, but we do not have it
 118             // available here, so we fall back to the next best thing.
 119             heldBack.sort(Comparator.comparing(DataTreeCandidateNode::name));
 120             for (var childNode : heldBack) {
 121                 ret |= serializeChild(path, childNode, skipData, changedLeafNodesOnly);
 122             }
 123         }
 124         return ret;
 125     }
 126
 127     private boolean serializeChild(final Deque<PathArgument> path, final DataTreeCandidateNode childNode,
 128             final boolean skipData, final boolean changedLeafNodesOnly) throws T {
 129         final boolean ret;
 130         path.add(childNode.name());
 131         ret = serializeLeafNodesOnly(path, childNode, skipData, changedLeafNodesOnly);
 132         path.removeLast();
 133         return ret;
 134     }
 135
 136     private boolean serializeChildNodesOnly(final Deque<PathArgument> path, final DataTreeCandidateNode current,
 137             final boolean skipData) throws T {
 138         return switch (current.modificationType()) {
 139             case APPEARED, WRITE -> serializeChildNodesOnlyTerminal(path, current, skipData, current.getDataAfter());
 140             case DISAPPEARED, DELETE -> serializeChildNodesOnlyTerminal(path, current, skipData,
 141                 current.getDataBefore());
 142             case SUBTREE_MODIFIED -> serializeChildNodesOnlyChildren(path, current, skipData);
 143             case UNMODIFIED -> false;
 144         };
 145     }
 146
 147     private boolean serializeChildNodesOnlyTerminal(final Deque<PathArgument> path, final DataTreeCandidateNode current,
 148             final boolean skipData, final NormalizedNode data) throws T {
 149         if (data instanceof ChoiceNode || data instanceof LeafSetNode || data instanceof MapNode) {
 150             return serializeChildNodesOnlyChildren(path, current, skipData);
 151         }
 152
 153         final var updated = !isNotUpdate(current);
 154         if (updated) {
 155             serializeData(path, current, skipData);
 156         }
 157         return updated;
 158     }
 159
 160     private boolean serializeChildNodesOnlyChildren(final Deque<PathArgument> path, final DataTreeCandidateNode current,
 161             final boolean skipData) throws T {
 162         var updated = false;
 163         for (var child : current.childNodes()) {
 164             path.add(child.name());
 165             updated |= serializeChildNodesOnly(path, child, skipData);
 166             path.removeLast();
 167         }
 168         return updated;
 169     }
 170
 171     private void serializeData(final Collection<PathArgument> dataPath, final DataTreeCandidateNode candidate,
 172             final boolean skipData) throws T {
 173         var stack = SchemaInferenceStack.of(context);
 174         DataSchemaContext current = DataSchemaContextTree.from(context).getRoot();
 175         for (var arg : dataPath) {
 176             final var next = current instanceof DataSchemaContext.Composite composite ? composite.enterChild(stack, arg)
 177                 : null;
 178             current = verifyNotNull(next,  "Failed to resolve %s: cannot find %s in %s", dataPath, arg, current);
 179         }
 180
 181         // Exit to parent if needed
 182         if (!stack.isEmpty()) {
 183             stack.exit();
 184         }
 185
 186         serializeData(stack.toInference(), dataPath, candidate, skipData);
 187     }
 188
 189     abstract void serializeData(Inference parent, Collection<PathArgument> dataPath, DataTreeCandidateNode candidate,
 190         boolean skipData) throws T;
 191
 192     private static boolean isNotUpdate(final DataTreeCandidateNode node) {
 193         final var before = node.dataBefore();
 194         final var after = node.dataAfter();
 195
 196         return before != null && after != null && before.body().equals(after.body());
 197     }
 198
 199     static final @Nullable NormalizedNode getDataAfter(final DataTreeCandidateNode candidate) {
 200         final var data = candidate.dataAfter();
 201         if (data instanceof MapEntryNode mapEntry) {
 202             return ImmutableNodes.newSystemMapBuilder()
 203                 .withNodeIdentifier(new NodeIdentifier(data.name().getNodeType()))
 204                 .withChild(mapEntry)
 205                 .build();
 206         }
 207         return data;
 208     }
 209
 210     static final @NonNull String modificationTypeToOperation(final DataTreeCandidateNode candidate) {
 211         final var operation = switch (candidate.modificationType()) {
 212             case APPEARED, SUBTREE_MODIFIED, WRITE -> candidate.dataBefore() != null ? Operation.Updated
 213                 : Operation.Created;
 214             case DELETE, DISAPPEARED -> Operation.Deleted;
 215             case UNMODIFIED -> {
 216                 throw new VerifyException("DataTreeCandidate for a notification is unmodified. Candidate: "
 217                     + candidate);
 218             }
 219         };
 220         return operation.getName();
 221     }
 222 }