cps-ri/src/main/java/org/onap/cps/spi/impl/CpsDataPersistenceServiceImpl.java

   1 /*
   2  *  ============LICENSE_START=======================================================
   3  *  Copyright (C) 2021-2022 Nordix Foundation
   4  *  Modifications Copyright (C) 2021 Pantheon.tech
   5  *  Modifications Copyright (C) 2020-2022 Bell Canada.
   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.spi.impl;
  24
  25 import static org.onap.cps.spi.FetchDescendantsOption.INCLUDE_ALL_DESCENDANTS;
  26
  27 import com.google.common.collect.ImmutableSet;
  28 import com.google.common.collect.ImmutableSet.Builder;
  29 import java.util.ArrayList;
  30 import java.util.Collection;
  31 import java.util.Collections;
  32 import java.util.HashMap;
  33 import java.util.HashSet;
  34 import java.util.List;
  35 import java.util.Map;
  36 import java.util.Set;
  37 import java.util.regex.Matcher;
  38 import java.util.regex.Pattern;
  39 import java.util.stream.Collectors;
  40 import javax.transaction.Transactional;
  41 import lombok.RequiredArgsConstructor;
  42 import lombok.extern.slf4j.Slf4j;
  43 import org.hibernate.StaleStateException;
  44 import org.onap.cps.cpspath.parser.CpsPathQuery;
  45 import org.onap.cps.cpspath.parser.CpsPathUtil;
  46 import org.onap.cps.cpspath.parser.PathParsingException;
  47 import org.onap.cps.spi.CpsDataPersistenceService;
  48 import org.onap.cps.spi.FetchDescendantsOption;
  49 import org.onap.cps.spi.entities.AnchorEntity;
  50 import org.onap.cps.spi.entities.DataspaceEntity;
  51 import org.onap.cps.spi.entities.FragmentEntity;
  52 import org.onap.cps.spi.entities.SchemaSetEntity;
  53 import org.onap.cps.spi.entities.YangResourceEntity;
  54 import org.onap.cps.spi.exceptions.AlreadyDefinedException;
  55 import org.onap.cps.spi.exceptions.ConcurrencyException;
  56 import org.onap.cps.spi.exceptions.CpsAdminException;
  57 import org.onap.cps.spi.exceptions.CpsPathException;
  58 import org.onap.cps.spi.exceptions.DataNodeNotFoundException;
  59 import org.onap.cps.spi.model.DataNode;
  60 import org.onap.cps.spi.model.DataNodeBuilder;
  61 import org.onap.cps.spi.repository.AnchorRepository;
  62 import org.onap.cps.spi.repository.DataspaceRepository;
  63 import org.onap.cps.spi.repository.FragmentRepository;
  64 import org.onap.cps.spi.utils.SessionManager;
  65 import org.onap.cps.utils.JsonObjectMapper;
  66 import org.onap.cps.yang.YangTextSchemaSourceSetBuilder;
  67 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  68 import org.springframework.dao.DataIntegrityViolationException;
  69 import org.springframework.stereotype.Service;
  70
  71 @Service
  72 @Slf4j
  73 @RequiredArgsConstructor
  74 public class CpsDataPersistenceServiceImpl implements CpsDataPersistenceService {
  75
  76     private final DataspaceRepository dataspaceRepository;
  77
  78     private final AnchorRepository anchorRepository;
  79
  80     private final FragmentRepository fragmentRepository;
  81
  82     private final JsonObjectMapper jsonObjectMapper;
  83
  84     private final SessionManager sessionManager;
  85
  86     private static final String REG_EX_FOR_OPTIONAL_LIST_INDEX = "(\\[@[\\s\\S]+?]){0,1})";
  87     private static final Pattern REG_EX_PATTERN_FOR_LIST_ELEMENT_KEY_PREDICATE =
  88             Pattern.compile("\\[(\\@([^\\/]{0,9999}))\\]$");
  89
  90     @Override
  91     @Transactional
  92     public void addChildDataNode(final String dataspaceName, final String anchorName, final String parentNodeXpath,
  93                                  final DataNode newChildDataNode) {
  94         addChildDataNodes(dataspaceName, anchorName, parentNodeXpath, Collections.singleton(newChildDataNode));
  95     }
  96
  97     @Override
  98     @Transactional
  99     public void addListElements(final String dataspaceName, final String anchorName, final String parentNodeXpath,
 100                                 final Collection<DataNode> newListElements) {
 101         addChildDataNodes(dataspaceName, anchorName, parentNodeXpath, newListElements);
 102     }
 103
 104     private void addChildDataNodes(final String dataspaceName, final String anchorName, final String parentNodeXpath,
 105                                    final Collection<DataNode> newChildren) {
 106         final FragmentEntity parentFragmentEntity = getFragmentByXpath(dataspaceName, anchorName, parentNodeXpath);
 107         try {
 108             final List<FragmentEntity> fragmentEntities = new ArrayList<>();
 109             newChildren.forEach(newChildAsDataNode -> {
 110                 final FragmentEntity newChildAsFragmentEntity = convertToFragmentWithAllDescendants(
 111                     parentFragmentEntity.getDataspace(),
 112                     parentFragmentEntity.getAnchor(),
 113                     newChildAsDataNode);
 114                 newChildAsFragmentEntity.setParentId(parentFragmentEntity.getId());
 115                 fragmentEntities.add(newChildAsFragmentEntity);
 116             });
 117             fragmentRepository.saveAll(fragmentEntities);
 118         } catch (final DataIntegrityViolationException exception) {
 119             final List<String> conflictXpaths = newChildren.stream()
 120                     .map(DataNode::getXpath)
 121                     .collect(Collectors.toList());
 122             throw AlreadyDefinedException.forDataNodes(conflictXpaths, anchorName, exception);
 123         }
 124     }
 125
 126     @Override
 127     public void storeDataNode(final String dataspaceName, final String anchorName, final DataNode dataNode) {
 128         final DataspaceEntity dataspaceEntity = dataspaceRepository.getByName(dataspaceName);
 129         final AnchorEntity anchorEntity = anchorRepository.getByDataspaceAndName(dataspaceEntity, anchorName);
 130         final FragmentEntity fragmentEntity = convertToFragmentWithAllDescendants(dataspaceEntity, anchorEntity,
 131                 dataNode);
 132         try {
 133             fragmentRepository.save(fragmentEntity);
 134         } catch (final DataIntegrityViolationException exception) {
 135             throw AlreadyDefinedException.forDataNode(dataNode.getXpath(), anchorName, exception);
 136         }
 137     }
 138
 139     /**
 140      * Convert DataNode object into Fragment and places the result in the fragments placeholder. Performs same action
 141      * for all DataNode children recursively.
 142      *
 143      * @param dataspaceEntity       dataspace
 144      * @param anchorEntity          anchorEntity
 145      * @param dataNodeToBeConverted dataNode
 146      * @return a Fragment built from current DataNode
 147      */
 148     private FragmentEntity convertToFragmentWithAllDescendants(final DataspaceEntity dataspaceEntity,
 149                              final AnchorEntity anchorEntity, final DataNode dataNodeToBeConverted) {
 150         final FragmentEntity parentFragment = toFragmentEntity(dataspaceEntity, anchorEntity, dataNodeToBeConverted);
 151         final Builder<FragmentEntity> childFragmentsImmutableSetBuilder = ImmutableSet.builder();
 152         for (final DataNode childDataNode : dataNodeToBeConverted.getChildDataNodes()) {
 153             final FragmentEntity childFragment =
 154                     convertToFragmentWithAllDescendants(parentFragment.getDataspace(), parentFragment.getAnchor(),
 155                             childDataNode);
 156             childFragmentsImmutableSetBuilder.add(childFragment);
 157         }
 158         parentFragment.setChildFragments(childFragmentsImmutableSetBuilder.build());
 159         return parentFragment;
 160     }
 161
 162     private FragmentEntity toFragmentEntity(final DataspaceEntity dataspaceEntity,
 163                                             final AnchorEntity anchorEntity, final DataNode dataNode) {
 164         return FragmentEntity.builder()
 165                 .dataspace(dataspaceEntity)
 166                 .anchor(anchorEntity)
 167                 .xpath(dataNode.getXpath())
 168                 .attributes(jsonObjectMapper.asJsonString(dataNode.getLeaves()))
 169                 .build();
 170     }
 171
 172     @Override
 173     public DataNode getDataNode(final String dataspaceName, final String anchorName, final String xpath,
 174                                 final FetchDescendantsOption fetchDescendantsOption) {
 175         final FragmentEntity fragmentEntity = getFragmentByXpath(dataspaceName, anchorName, xpath);
 176         return toDataNode(fragmentEntity, fetchDescendantsOption);
 177     }
 178
 179     private FragmentEntity getFragmentByXpath(final String dataspaceName, final String anchorName,
 180                                               final String xpath) {
 181         final DataspaceEntity dataspaceEntity = dataspaceRepository.getByName(dataspaceName);
 182         final AnchorEntity anchorEntity = anchorRepository.getByDataspaceAndName(dataspaceEntity, anchorName);
 183         if (isRootXpath(xpath)) {
 184             return fragmentRepository.findFirstRootByDataspaceAndAnchor(dataspaceEntity, anchorEntity);
 185         } else {
 186             final String normalizedXpath;
 187             try {
 188                 normalizedXpath = CpsPathUtil.getNormalizedXpath(xpath);
 189             } catch (final PathParsingException e) {
 190                 throw new CpsPathException(e.getMessage());
 191             }
 192             return fragmentRepository.getByDataspaceAndAnchorAndXpath(dataspaceEntity, anchorEntity,
 193                     normalizedXpath);
 194         }
 195     }
 196
 197     @Override
 198     public List<DataNode> queryDataNodes(final String dataspaceName, final String anchorName, final String cpsPath,
 199                                          final FetchDescendantsOption fetchDescendantsOption) {
 200         final DataspaceEntity dataspaceEntity = dataspaceRepository.getByName(dataspaceName);
 201         final AnchorEntity anchorEntity = anchorRepository.getByDataspaceAndName(dataspaceEntity, anchorName);
 202         final CpsPathQuery cpsPathQuery;
 203         try {
 204             cpsPathQuery = CpsPathUtil.getCpsPathQuery(cpsPath);
 205         } catch (final PathParsingException e) {
 206             throw new CpsPathException(e.getMessage());
 207         }
 208         List<FragmentEntity> fragmentEntities =
 209                 fragmentRepository.findByAnchorAndCpsPath(anchorEntity.getId(), cpsPathQuery);
 210         if (cpsPathQuery.hasAncestorAxis()) {
 211             final Set<String> ancestorXpaths = processAncestorXpath(fragmentEntities, cpsPathQuery);
 212             fragmentEntities = ancestorXpaths.isEmpty() ? Collections.emptyList()
 213                     : fragmentRepository.findAllByAnchorAndXpathIn(anchorEntity, ancestorXpaths);
 214         }
 215         return fragmentEntities.stream()
 216                 .map(fragmentEntity -> toDataNode(fragmentEntity, fetchDescendantsOption))
 217                 .collect(Collectors.toUnmodifiableList());
 218     }
 219
 220     @Override
 221     public String startSession() {
 222         return sessionManager.startSession();
 223     }
 224
 225     @Override
 226     public void closeSession(final String sessionId) {
 227         sessionManager.closeSession(sessionId, SessionManager.WITH_COMMIT);
 228     }
 229
 230     @Override
 231     public void lockAnchor(final String sessionId, final String dataspaceName,
 232                            final String anchorName, final Long timeoutInMilliseconds) {
 233         sessionManager.lockAnchor(sessionId, dataspaceName, anchorName, timeoutInMilliseconds);
 234     }
 235
 236     private static Set<String> processAncestorXpath(final List<FragmentEntity> fragmentEntities,
 237                                                     final CpsPathQuery cpsPathQuery) {
 238         final Set<String> ancestorXpath = new HashSet<>();
 239         final Pattern pattern =
 240                 Pattern.compile("([\\s\\S]*\\/" + Pattern.quote(cpsPathQuery.getAncestorSchemaNodeIdentifier())
 241                         + REG_EX_FOR_OPTIONAL_LIST_INDEX + "\\/[\\s\\S]*");
 242         for (final FragmentEntity fragmentEntity : fragmentEntities) {
 243             final Matcher matcher = pattern.matcher(fragmentEntity.getXpath());
 244             if (matcher.matches()) {
 245                 ancestorXpath.add(matcher.group(1));
 246             }
 247         }
 248         return ancestorXpath;
 249     }
 250
 251     private DataNode toDataNode(final FragmentEntity fragmentEntity,
 252                                 final FetchDescendantsOption fetchDescendantsOption) {
 253         final List<DataNode> childDataNodes = getChildDataNodes(fragmentEntity, fetchDescendantsOption);
 254         Map<String, Object> leaves = new HashMap<>();
 255         if (fragmentEntity.getAttributes() != null) {
 256             leaves = jsonObjectMapper.convertJsonString(fragmentEntity.getAttributes(), Map.class);
 257         }
 258         return new DataNodeBuilder()
 259                 .withModuleNamePrefix(getFirstModuleName(fragmentEntity))
 260                 .withXpath(fragmentEntity.getXpath())
 261                 .withLeaves(leaves)
 262                 .withChildDataNodes(childDataNodes).build();
 263     }
 264
 265     private String getFirstModuleName(final FragmentEntity fragmentEntity) {
 266         final SchemaSetEntity schemaSetEntity = fragmentEntity.getAnchor().getSchemaSet();
 267         final Map<String, String> yangResourceNameToContent =
 268                 schemaSetEntity.getYangResources().stream().collect(
 269                         Collectors.toMap(YangResourceEntity::getFileName, YangResourceEntity::getContent));
 270         final SchemaContext schemaContext = YangTextSchemaSourceSetBuilder.of(yangResourceNameToContent)
 271                 .getSchemaContext();
 272         return schemaContext.getModules().iterator().next().getName();
 273     }
 274
 275     private List<DataNode> getChildDataNodes(final FragmentEntity fragmentEntity,
 276                                              final FetchDescendantsOption fetchDescendantsOption) {
 277         if (fetchDescendantsOption == INCLUDE_ALL_DESCENDANTS) {
 278             return fragmentEntity.getChildFragments().stream()
 279                     .map(childFragmentEntity -> toDataNode(childFragmentEntity, fetchDescendantsOption))
 280                     .collect(Collectors.toUnmodifiableList());
 281         }
 282         return Collections.emptyList();
 283     }
 284
 285     @Override
 286     public void updateDataLeaves(final String dataspaceName, final String anchorName, final String xpath,
 287                                  final Map<String, Object> leaves) {
 288         final FragmentEntity fragmentEntity = getFragmentByXpath(dataspaceName, anchorName, xpath);
 289         fragmentEntity.setAttributes(jsonObjectMapper.asJsonString(leaves));
 290         fragmentRepository.save(fragmentEntity);
 291     }
 292
 293     @Override
 294     public void updateDataNodeAndDescendants(final String dataspaceName, final String anchorName,
 295                                              final DataNode dataNode) {
 296         final FragmentEntity fragmentEntity = getFragmentByXpath(dataspaceName, anchorName, dataNode.getXpath());
 297         updateFragmentEntityAndDescendantsWithDataNode(fragmentEntity, dataNode);
 298         try {
 299             fragmentRepository.save(fragmentEntity);
 300         } catch (final StaleStateException staleStateException) {
 301             throw new ConcurrencyException("Concurrent Transactions",
 302                     String.format("dataspace :'%s', Anchor : '%s' and xpath: '%s' is updated by another transaction.",
 303                             dataspaceName, anchorName, dataNode.getXpath()),
 304                     staleStateException);
 305         }
 306     }
 307
 308     @Override
 309     public void updateDataNodesAndDescendants(final String dataspaceName,
 310                                               final String anchorName,
 311                                               final List<DataNode> dataNodes) {
 312         final Map<DataNode, FragmentEntity> dataNodeFragmentEntityMap = dataNodes.stream()
 313             .collect(Collectors.toMap(
 314                 dataNode -> dataNode, dataNode -> getFragmentByXpath(dataspaceName, anchorName, dataNode.getXpath())));
 315         dataNodeFragmentEntityMap.forEach(
 316             (dataNode, fragmentEntity) -> updateFragmentEntityAndDescendantsWithDataNode(fragmentEntity, dataNode));
 317         try {
 318             fragmentRepository.saveAll(dataNodeFragmentEntityMap.values());
 319         } catch (final StaleStateException staleStateException) {
 320             throw new ConcurrencyException("Concurrent Transactions",
 321                 String.format("A data node in dataspace :'%s' with Anchor : '%s' is updated by another transaction.",
 322                     dataspaceName, anchorName),
 323                 staleStateException);
 324         }
 325     }
 326
 327     private void updateFragmentEntityAndDescendantsWithDataNode(final FragmentEntity existingFragmentEntity,
 328                                                                 final DataNode newDataNode) {
 329
 330         existingFragmentEntity.setAttributes(jsonObjectMapper.asJsonString(newDataNode.getLeaves()));
 331
 332         final Map<String, FragmentEntity> existingChildrenByXpath = existingFragmentEntity.getChildFragments().stream()
 333                 .collect(Collectors.toMap(FragmentEntity::getXpath, childFragmentEntity -> childFragmentEntity));
 334
 335         final Collection<FragmentEntity> updatedChildFragments = new HashSet<>();
 336
 337         for (final DataNode newDataNodeChild : newDataNode.getChildDataNodes()) {
 338             final FragmentEntity childFragment;
 339             if (isNewDataNode(newDataNodeChild, existingChildrenByXpath)) {
 340                 childFragment = convertToFragmentWithAllDescendants(
 341                         existingFragmentEntity.getDataspace(), existingFragmentEntity.getAnchor(), newDataNodeChild);
 342             } else {
 343                 childFragment = existingChildrenByXpath.get(newDataNodeChild.getXpath());
 344                 updateFragmentEntityAndDescendantsWithDataNode(childFragment, newDataNodeChild);
 345             }
 346             updatedChildFragments.add(childFragment);
 347         }
 348
 349         existingFragmentEntity.getChildFragments().clear();
 350         existingFragmentEntity.getChildFragments().addAll(updatedChildFragments);
 351     }
 352
 353     @Override
 354     @Transactional
 355     public void replaceListContent(final String dataspaceName, final String anchorName, final String parentNodeXpath,
 356                                    final Collection<DataNode> newListElements) {
 357         final FragmentEntity parentEntity = getFragmentByXpath(dataspaceName, anchorName, parentNodeXpath);
 358         final String listElementXpathPrefix = getListElementXpathPrefix(newListElements);
 359         final Map<String, FragmentEntity> existingListElementFragmentEntitiesByXPath =
 360                 extractListElementFragmentEntitiesByXPath(parentEntity.getChildFragments(), listElementXpathPrefix);
 361         deleteListElements(parentEntity.getChildFragments(), existingListElementFragmentEntitiesByXPath);
 362         final Set<FragmentEntity> updatedChildFragmentEntities = new HashSet<>();
 363         for (final DataNode newListElement : newListElements) {
 364             final FragmentEntity existingListElementEntity =
 365                     existingListElementFragmentEntitiesByXPath.get(newListElement.getXpath());
 366             final FragmentEntity entityToBeAdded = getFragmentForReplacement(parentEntity, newListElement,
 367                     existingListElementEntity);
 368
 369             updatedChildFragmentEntities.add(entityToBeAdded);
 370         }
 371         parentEntity.getChildFragments().addAll(updatedChildFragmentEntities);
 372         fragmentRepository.save(parentEntity);
 373     }
 374
 375     @Override
 376     @Transactional
 377     public void deleteDataNodes(final String dataspaceName, final String anchorName) {
 378         final DataspaceEntity dataspaceEntity = dataspaceRepository.getByName(dataspaceName);
 379         anchorRepository.findByDataspaceAndName(dataspaceEntity, anchorName)
 380                 .ifPresent(
 381                         anchorEntity -> fragmentRepository.deleteByAnchorIn(Set.of(anchorEntity)));
 382     }
 383
 384     @Override
 385     @Transactional
 386     public void deleteListDataNode(final String dataspaceName, final String anchorName,
 387                                    final String targetXpath) {
 388         deleteDataNode(dataspaceName, anchorName, targetXpath, true);
 389     }
 390
 391     @Override
 392     @Transactional
 393     public void deleteDataNode(final String dataspaceName, final String anchorName, final String targetXpath) {
 394         deleteDataNode(dataspaceName, anchorName, targetXpath, false);
 395     }
 396
 397     private void deleteDataNode(final String dataspaceName, final String anchorName, final String targetXpath,
 398                                 final boolean onlySupportListNodeDeletion) {
 399         final String parentNodeXpath;
 400         FragmentEntity parentFragmentEntity = null;
 401         boolean targetDeleted = false;
 402         if (isRootXpath(targetXpath)) {
 403             deleteDataNodes(dataspaceName, anchorName);
 404             targetDeleted = true;
 405         } else {
 406             if (isRootContainerNodeXpath(targetXpath)) {
 407                 parentNodeXpath = targetXpath;
 408             } else {
 409                 parentNodeXpath = targetXpath.substring(0, targetXpath.lastIndexOf('/'));
 410             }
 411             parentFragmentEntity = getFragmentByXpath(dataspaceName, anchorName, parentNodeXpath);
 412             final String lastXpathElement = targetXpath.substring(targetXpath.lastIndexOf('/'));
 413             final boolean isListElement = REG_EX_PATTERN_FOR_LIST_ELEMENT_KEY_PREDICATE
 414                     .matcher(lastXpathElement).find();
 415             if (isListElement) {
 416                 targetDeleted = deleteDataNode(parentFragmentEntity, targetXpath);
 417             } else {
 418                 targetDeleted = deleteAllListElements(parentFragmentEntity, targetXpath);
 419                 final boolean tryToDeleteDataNode = !targetDeleted && !onlySupportListNodeDeletion;
 420                 if (tryToDeleteDataNode) {
 421                     targetDeleted = deleteDataNode(parentFragmentEntity, targetXpath);
 422                 }
 423             }
 424         }
 425         if (!targetDeleted) {
 426             final String additionalInformation = onlySupportListNodeDeletion
 427                     ? "The target is probably not a List." : "";
 428             throw new DataNodeNotFoundException(parentFragmentEntity.getDataspace().getName(),
 429                     parentFragmentEntity.getAnchor().getName(), targetXpath, additionalInformation);
 430         }
 431     }
 432
 433     private boolean deleteDataNode(final FragmentEntity parentFragmentEntity, final String targetXpath) {
 434         final String normalizedTargetXpath = CpsPathUtil.getNormalizedXpath(targetXpath);
 435         if (parentFragmentEntity.getXpath().equals(normalizedTargetXpath)) {
 436             fragmentRepository.delete(parentFragmentEntity);
 437             return true;
 438         }
 439         if (parentFragmentEntity.getChildFragments()
 440                 .removeIf(fragment -> fragment.getXpath().equals(normalizedTargetXpath))) {
 441             fragmentRepository.save(parentFragmentEntity);
 442             return true;
 443         }
 444         return false;
 445     }
 446
 447     private boolean deleteAllListElements(final FragmentEntity parentFragmentEntity, final String listXpath) {
 448         final String normalizedListXpath = CpsPathUtil.getNormalizedXpath(listXpath);
 449         final String deleteTargetXpathPrefix = normalizedListXpath + "[";
 450         if (parentFragmentEntity.getChildFragments()
 451                 .removeIf(fragment -> fragment.getXpath().startsWith(deleteTargetXpathPrefix))) {
 452             fragmentRepository.save(parentFragmentEntity);
 453             return true;
 454         }
 455         return false;
 456     }
 457
 458     private static void deleteListElements(
 459             final Collection<FragmentEntity> fragmentEntities,
 460             final Map<String, FragmentEntity> existingListElementFragmentEntitiesByXPath) {
 461         fragmentEntities.removeAll(existingListElementFragmentEntitiesByXPath.values());
 462     }
 463
 464     private static String getListElementXpathPrefix(final Collection<DataNode> newListElements) {
 465         if (newListElements.isEmpty()) {
 466             throw new CpsAdminException("Invalid list replacement",
 467                     "Cannot replace list elements with empty collection");
 468         }
 469         final String firstChildNodeXpath = newListElements.iterator().next().getXpath();
 470         return firstChildNodeXpath.substring(0, firstChildNodeXpath.lastIndexOf('[') + 1);
 471     }
 472
 473     private FragmentEntity getFragmentForReplacement(final FragmentEntity parentEntity,
 474                                                      final DataNode newListElement,
 475                                                      final FragmentEntity existingListElementEntity) {
 476         if (existingListElementEntity == null) {
 477             return convertToFragmentWithAllDescendants(
 478                     parentEntity.getDataspace(), parentEntity.getAnchor(), newListElement);
 479         }
 480         if (newListElement.getChildDataNodes().isEmpty()) {
 481             copyAttributesFromNewListElement(existingListElementEntity, newListElement);
 482             existingListElementEntity.getChildFragments().clear();
 483         } else {
 484             updateFragmentEntityAndDescendantsWithDataNode(existingListElementEntity, newListElement);
 485         }
 486         return existingListElementEntity;
 487     }
 488
 489     private static boolean isNewDataNode(final DataNode replacementDataNode,
 490                                          final Map<String, FragmentEntity> existingListElementsByXpath) {
 491         return !existingListElementsByXpath.containsKey(replacementDataNode.getXpath());
 492     }
 493
 494     private static boolean isRootContainerNodeXpath(final String xpath) {
 495         return 0 == xpath.lastIndexOf('/');
 496     }
 497
 498     private void copyAttributesFromNewListElement(final FragmentEntity existingListElementEntity,
 499                                                   final DataNode newListElement) {
 500         final FragmentEntity replacementFragmentEntity =
 501                 FragmentEntity.builder().attributes(jsonObjectMapper.asJsonString(
 502                         newListElement.getLeaves())).build();
 503         existingListElementEntity.setAttributes(replacementFragmentEntity.getAttributes());
 504     }
 505
 506     private static Map<String, FragmentEntity> extractListElementFragmentEntitiesByXPath(
 507             final Set<FragmentEntity> childEntities, final String listElementXpathPrefix) {
 508         return childEntities.stream()
 509                 .filter(fragmentEntity -> fragmentEntity.getXpath().startsWith(listElementXpathPrefix))
 510                 .collect(Collectors.toMap(FragmentEntity::getXpath, fragmentEntity -> fragmentEntity));
 511     }
 512
 513     private static boolean isRootXpath(final String xpath) {
 514         return "/".equals(xpath) || "".equals(xpath);
 515     }
 516 }