cps-service/src/main/java/org/onap/cps/utils/YangUtils.java

   1 /*
   2  *  ============LICENSE_START=======================================================
   3  *  Copyright (C) 2020-2022 Nordix Foundation
   4  *  Modifications Copyright (C) 2021 Bell Canada.
   5  *  Modifications Copyright (C) 2021 Pantheon.tech
   6  *  ================================================================================
   7  *  Licensed under the Apache License, Version 2.0 (the "License");
   8  *  you may not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *
  11  *        http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  *  Unless required by applicable law or agreed to in writing, software
  14  *  distributed under the License is distributed on an "AS IS" BASIS,
  15  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  *  See the License for the specific language governing permissions and
  17  *  limitations under the License.
  18  *
  19  *  SPDX-License-Identifier: Apache-2.0
  20  *  ============LICENSE_END=========================================================
  21  */
  22
  23 package org.onap.cps.utils;
  24
  25 import com.google.gson.JsonSyntaxException;
  26 import com.google.gson.stream.JsonReader;
  27 import java.io.IOException;
  28 import java.io.StringReader;
  29 import java.util.ArrayList;
  30 import java.util.Arrays;
  31 import java.util.Collection;
  32 import java.util.Collections;
  33 import java.util.List;
  34 import java.util.Optional;
  35 import java.util.stream.Collectors;
  36 import lombok.AccessLevel;
  37 import lombok.NoArgsConstructor;
  38 import lombok.extern.slf4j.Slf4j;
  39 import org.onap.cps.spi.exceptions.DataValidationException;
  40 import org.opendaylight.yangtools.yang.common.QName;
  41 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  42 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  43 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  44 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
  45 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  46 import org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream;
  47 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
  48 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
  49 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
  50 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
  51 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  52 import org.opendaylight.yangtools.yang.model.api.EffectiveStatementInference;
  53 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  54 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier;
  55 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack;
  56
  57 @Slf4j
  58 @NoArgsConstructor(access = AccessLevel.PRIVATE)
  59 public class YangUtils {
  60
  61     private static final String XPATH_DELIMITER_REGEX = "\\/";
  62     private static final String XPATH_NODE_KEY_ATTRIBUTES_REGEX = "\\[.*?\\]";
  63
  64     /**
  65      * Parses jsonData into NormalizedNode according to given schema context.
  66      *
  67      * @param jsonData      json data as string
  68      * @param schemaContext schema context describing associated data model
  69      * @return the NormalizedNode object
  70      */
  71     public static NormalizedNode parseJsonData(final String jsonData, final SchemaContext schemaContext) {
  72         return parseJsonData(jsonData, schemaContext, Optional.empty());
  73     }
  74
  75     /**
  76      * Parses jsonData into NormalizedNode according to given schema context.
  77      *
  78      * @param jsonData        json data fragment as string
  79      * @param schemaContext   schema context describing associated data model
  80      * @param parentNodeXpath the xpath referencing the parent node current data fragment belong to
  81      * @return the NormalizedNode object
  82      */
  83     public static NormalizedNode parseJsonData(final String jsonData, final SchemaContext schemaContext,
  84         final String parentNodeXpath) {
  85         final Collection<QName> dataSchemaNodeIdentifiers =
  86                 getDataSchemaNodeIdentifiersByXpath(parentNodeXpath, schemaContext);
  87         return parseJsonData(jsonData, schemaContext, Optional.of(dataSchemaNodeIdentifiers));
  88     }
  89
  90     private static NormalizedNode parseJsonData(final String jsonData, final SchemaContext schemaContext,
  91         final Optional<Collection<QName>> dataSchemaNodeIdentifiers) {
  92         final JSONCodecFactory jsonCodecFactory = JSONCodecFactorySupplier.DRAFT_LHOTKA_NETMOD_YANG_JSON_02
  93             .getShared((EffectiveModelContext) schemaContext);
  94         final NormalizedNodeResult normalizedNodeResult = new NormalizedNodeResult();
  95         final NormalizedNodeStreamWriter normalizedNodeStreamWriter = ImmutableNormalizedNodeStreamWriter
  96             .from(normalizedNodeResult);
  97         final JsonReader jsonReader = new JsonReader(new StringReader(jsonData));
  98         final JsonParserStream jsonParserStream;
  99
 100         if (dataSchemaNodeIdentifiers.isPresent()) {
 101             final EffectiveModelContext effectiveModelContext = ((EffectiveModelContext) schemaContext);
 102             final EffectiveStatementInference effectiveStatementInference =
 103                     SchemaInferenceStack.of(effectiveModelContext,
 104                     SchemaNodeIdentifier.Absolute.of(dataSchemaNodeIdentifiers.get())).toInference();
 105             jsonParserStream =
 106                     JsonParserStream.create(normalizedNodeStreamWriter, jsonCodecFactory, effectiveStatementInference);
 107         } else {
 108             jsonParserStream = JsonParserStream.create(normalizedNodeStreamWriter, jsonCodecFactory);
 109         }
 110
 111         try {
 112             jsonParserStream.parse(jsonReader);
 113             jsonParserStream.close();
 114         } catch (final JsonSyntaxException exception) {
 115             throw new DataValidationException(
 116                 "Failed to parse json data: " + jsonData, exception.getMessage(), exception);
 117         } catch (final IOException | IllegalStateException illegalStateException) {
 118             throw new DataValidationException(
 119                 "Failed to parse json data. Unsupported xpath or json data:" + jsonData, illegalStateException
 120                 .getMessage(), illegalStateException);
 121         }
 122         return normalizedNodeResult.getResult();
 123     }
 124
 125     /**
 126      * Create an xpath form a Yang Tools NodeIdentifier (i.e. PathArgument).
 127      *
 128      * @param nodeIdentifier the NodeIdentifier
 129      * @return an xpath
 130      */
 131     public static String buildXpath(final YangInstanceIdentifier.PathArgument nodeIdentifier) {
 132         final StringBuilder xpathBuilder = new StringBuilder();
 133         xpathBuilder.append("/").append(nodeIdentifier.getNodeType().getLocalName());
 134
 135         if (nodeIdentifier instanceof YangInstanceIdentifier.NodeIdentifierWithPredicates) {
 136             xpathBuilder.append(getKeyAttributesStatement(
 137                 (YangInstanceIdentifier.NodeIdentifierWithPredicates) nodeIdentifier));
 138         }
 139         return xpathBuilder.toString();
 140     }
 141
 142
 143     private static String getKeyAttributesStatement(
 144         final YangInstanceIdentifier.NodeIdentifierWithPredicates nodeIdentifier) {
 145         final List<String> keyAttributes = nodeIdentifier.entrySet().stream().map(
 146             entry -> {
 147                 final String name = entry.getKey().getLocalName();
 148                 final String value = String.valueOf(entry.getValue()).replace("'", "\\'");
 149                 return String.format("@%s='%s'", name, value);
 150             }
 151         ).collect(Collectors.toList());
 152
 153         if (keyAttributes.isEmpty()) {
 154             return "";
 155         } else {
 156             Collections.sort(keyAttributes);
 157             return "[" + String.join(" and ", keyAttributes) + "]";
 158         }
 159     }
 160
 161     private static Collection<QName> getDataSchemaNodeIdentifiersByXpath(final String parentNodeXpath,
 162                                                                       final SchemaContext schemaContext) {
 163         final String[] xpathNodeIdSequence = xpathToNodeIdSequence(parentNodeXpath);
 164         return findDataSchemaNodeIdentifiersByXpathNodeIdSequence(xpathNodeIdSequence, schemaContext.getChildNodes(),
 165                 new ArrayList<>());
 166     }
 167
 168     private static String[] xpathToNodeIdSequence(final String xpath) {
 169         final String[] xpathNodeIdSequence = Arrays.stream(xpath
 170                         .replaceAll(XPATH_NODE_KEY_ATTRIBUTES_REGEX, "")
 171                         .split(XPATH_DELIMITER_REGEX))
 172                 .filter(identifier -> !identifier.isEmpty())
 173                 .toArray(String[]::new);
 174         if (xpathNodeIdSequence.length < 1) {
 175             throw new DataValidationException("Invalid xpath.", "Xpath contains no node identifiers.");
 176         }
 177         return xpathNodeIdSequence;
 178     }
 179
 180     private static Collection<QName> findDataSchemaNodeIdentifiersByXpathNodeIdSequence(
 181             final String[] xpathNodeIdSequence,
 182             final Collection<? extends DataSchemaNode> dataSchemaNodes,
 183             final Collection<QName> dataSchemaNodeIdentifiers) {
 184         final String currentXpathNodeId = xpathNodeIdSequence[0];
 185         final DataSchemaNode currentDataSchemaNode = dataSchemaNodes.stream()
 186             .filter(dataSchemaNode -> currentXpathNodeId.equals(dataSchemaNode.getQName().getLocalName()))
 187             .findFirst().orElseThrow(() -> schemaNodeNotFoundException(currentXpathNodeId));
 188         dataSchemaNodeIdentifiers.add(currentDataSchemaNode.getQName());
 189         if (xpathNodeIdSequence.length <= 1) {
 190             return dataSchemaNodeIdentifiers;
 191         }
 192         if (currentDataSchemaNode instanceof DataNodeContainer) {
 193             return findDataSchemaNodeIdentifiersByXpathNodeIdSequence(
 194                 getNextLevelXpathNodeIdSequence(xpathNodeIdSequence),
 195                     ((DataNodeContainer) currentDataSchemaNode).getChildNodes(),
 196                     dataSchemaNodeIdentifiers);
 197         }
 198         throw schemaNodeNotFoundException(xpathNodeIdSequence[1]);
 199     }
 200
 201     private static String[] getNextLevelXpathNodeIdSequence(final String[] xpathNodeIdSequence) {
 202         final String[] nextXpathNodeIdSequence = new String[xpathNodeIdSequence.length - 1];
 203         System.arraycopy(xpathNodeIdSequence, 1, nextXpathNodeIdSequence, 0, nextXpathNodeIdSequence.length);
 204         return nextXpathNodeIdSequence;
 205     }
 206
 207     private static DataValidationException schemaNodeNotFoundException(final String schemaNodeIdentifier) {
 208         return new DataValidationException("Invalid xpath.",
 209             String.format("No schema node was found for xpath identifier '%s'.", schemaNodeIdentifier));
 210     }
 211 }