restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/restconf/utils/parser/ParserFieldsParameter.java

   1 /*
   2  * Copyright (c) 2016 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
   9 package org.opendaylight.restconf.utils.parser;
  10
  11 import java.util.ArrayList;
  12 import java.util.HashSet;
  13 import java.util.List;
  14 import java.util.Set;
  15 import javax.annotation.Nonnull;
  16 import javax.annotation.Nullable;
  17 import org.opendaylight.restconf.common.context.InstanceIdentifierContext;
  18 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  19 import org.opendaylight.restconf.common.errors.RestconfError.ErrorTag;
  20 import org.opendaylight.restconf.common.errors.RestconfError.ErrorType;
  21 import org.opendaylight.restconf.utils.parser.builder.ParserBuilderConstants.Deserializer;
  22 import org.opendaylight.yangtools.yang.common.QName;
  23 import org.opendaylight.yangtools.yang.common.QNameModule;
  24 import org.opendaylight.yangtools.yang.data.util.DataSchemaContextNode;
  25 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
  26 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  27
  28 public class ParserFieldsParameter {
  29     private static final char COLON = ':';
  30     private static final char SEMICOLON = ';';
  31     private static final char SLASH = '/';
  32     private static final char STARTING_PARENTHESIS = '(';
  33     private static final char CLOSING_PARENTHESIS = ')';
  34
  35     /**
  36      * Parse fields parameter and return complete list of child nodes organized into levels.
  37      * @param identifier identifier context created from request URI
  38      * @param input input value of fields parameter
  39      * @return {@link List}
  40      */
  41     @Nonnull
  42     public static List<Set<QName>> parseFieldsParameter(@Nonnull final InstanceIdentifierContext<?> identifier,
  43                                                         @Nonnull final String input) {
  44         final List<Set<QName>> parsed = new ArrayList<>();
  45         final SchemaContext context = identifier.getSchemaContext();
  46         final QNameModule startQNameModule = identifier.getSchemaNode().getQName().getModule();
  47         final DataSchemaContextNode<?> startNode = DataSchemaContextNode.fromDataSchemaNode(
  48                 (DataSchemaNode) identifier.getSchemaNode());
  49
  50         if (startNode == null) {
  51             throw new RestconfDocumentedException(
  52                     "Start node missing in " + input, ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
  53         }
  54
  55         parseInput(input, startQNameModule, startNode, parsed, context);
  56         return parsed;
  57     }
  58
  59     /**
  60      * Parse input value of fields parameter and create list of sets. Each set represents one level of child nodes.
  61      * @param input input value of fields parameter
  62      * @param startQNameModule starting qname module
  63      * @param startNode starting node
  64      * @param parsed list of results
  65      * @param context schema context
  66      */
  67     private static void parseInput(@Nonnull final String input,
  68                                    @Nonnull final QNameModule startQNameModule,
  69                                    @Nonnull final DataSchemaContextNode<?> startNode,
  70                                    @Nonnull final List<Set<QName>> parsed,
  71                                    @Nonnull final SchemaContext context) {
  72         int currentPosition = 0;
  73         int startPosition = 0;
  74         DataSchemaContextNode<?> currentNode = startNode;
  75         QNameModule currentQNameModule = startQNameModule;
  76
  77         Set<QName> currentLevel = new HashSet<>();
  78         parsed.add(currentLevel);
  79
  80         while (currentPosition < input.length()) {
  81             final char currentChar = input.charAt(currentPosition);
  82
  83             if (Deserializer.IDENTIFIER.matches(currentChar) || currentChar == '/') {
  84                 if (currentChar == SLASH) {
  85                     // add parsed identifier to results for current level
  86                     currentNode = addChildToResult(
  87                             currentNode,
  88                             input.substring(startPosition, currentPosition), currentQNameModule, currentLevel);
  89                     // go one level down
  90                     currentLevel = new HashSet<>();
  91                     parsed.add(currentLevel);
  92
  93                     currentPosition++;
  94                     startPosition = currentPosition;
  95                 } else {
  96                     currentPosition++;
  97                 }
  98
  99                 continue;
 100             }
 101
 102             switch (currentChar) {
 103                 case COLON :
 104                     // new namespace and revision found
 105                     currentQNameModule = context.findModuleByName(
 106                             input.substring(startPosition, currentPosition), null).getQNameModule();
 107                     currentPosition++;
 108                     break;
 109                 case STARTING_PARENTHESIS:
 110                     // add current child to parsed results for current level
 111                     final DataSchemaContextNode<?> child = addChildToResult(
 112                             currentNode,
 113                             input.substring(startPosition, currentPosition), currentQNameModule, currentLevel);
 114                     // call with child node as new start node for one level down
 115                     int closingParenthesis = currentPosition
 116                             + findClosingParenthesis(input.substring(currentPosition + 1));
 117                     parseInput(
 118                             input.substring(currentPosition + 1, closingParenthesis),
 119                             currentQNameModule,
 120                             child,
 121                             parsed,
 122                             context);
 123
 124                     // closing parenthesis must be at the end of input or separator and one more character is expected
 125                     currentPosition = closingParenthesis + 1;
 126                     if (currentPosition != input.length()) {
 127                         if (currentPosition + 1 < input.length()) {
 128                             if (input.charAt(currentPosition) == SEMICOLON) {
 129                                 currentPosition++;
 130                             } else {
 131                                 throw new RestconfDocumentedException(
 132                                         "Missing semicolon character after "
 133                                                 + child.getIdentifier().getNodeType().getLocalName()
 134                                                 + " child nodes",
 135                                         ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 136                             }
 137                         } else {
 138                             throw new RestconfDocumentedException(
 139                                     "Unexpected character '"
 140                                             + input.charAt(currentPosition)
 141                                             + "' found in fields parameter value",
 142                                     ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 143                         }
 144                     }
 145
 146                     break;
 147                 case SEMICOLON:
 148                     // complete identifier found
 149                     addChildToResult(
 150                             currentNode,
 151                             input.substring(startPosition, currentPosition), currentQNameModule, currentLevel);
 152                     currentPosition++;
 153                     break;
 154                 default:
 155                     throw new RestconfDocumentedException(
 156                             "Unexpected character '" + currentChar + "' found in fields parameter value",
 157                             ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 158             }
 159
 160             startPosition = currentPosition;
 161         }
 162
 163         // parse input to end
 164         if (startPosition < input.length()) {
 165             addChildToResult(currentNode, input.substring(startPosition), currentQNameModule, currentLevel);
 166         }
 167     }
 168
 169     /**
 170      * Add parsed child of current node to result for current level.
 171      * @param currentNode current node
 172      * @param identifier parsed identifier of child node
 173      * @param currentQNameModule current namespace and revision in {@link QNameModule}
 174      * @param level current nodes level
 175      * @return {@link DataSchemaContextNode}
 176      */
 177     @Nonnull
 178     private static DataSchemaContextNode<?> addChildToResult(
 179             @Nonnull final DataSchemaContextNode<?> currentNode,
 180             @Nonnull final String identifier,
 181             @Nonnull final QNameModule currentQNameModule,
 182             @Nonnull final Set<QName> level) {
 183         final QName childQName = QName.create(
 184                 currentQNameModule.getNamespace().toString(),
 185                 identifier,
 186                 currentQNameModule.getRevision());
 187
 188         // resolve parent node
 189         final DataSchemaContextNode<?> parentNode = resolveMixinNode(
 190                 currentNode, level, currentNode.getIdentifier().getNodeType());
 191         if (parentNode == null) {
 192             throw new RestconfDocumentedException(
 193                     "Not-mixin node missing in " + currentNode.getIdentifier().getNodeType().getLocalName(),
 194                     ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 195         }
 196
 197         // resolve child node
 198         final DataSchemaContextNode<?> childNode = resolveMixinNode(
 199                 parentNode.getChild(childQName), level, childQName);
 200         if (childNode == null) {
 201             throw new RestconfDocumentedException(
 202                     "Child " + identifier + " node missing in "
 203                             + currentNode.getIdentifier().getNodeType().getLocalName(),
 204                     ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 205         }
 206
 207         // add final childNode node to level nodes
 208         level.add(childNode.getIdentifier().getNodeType());
 209         return childNode;
 210     }
 211
 212     /**
 213      * Resolve mixin node by searching for inner nodes until not mixin node or null is found.
 214      * All nodes expect of not mixin node are added to current level nodes.
 215      * @param node initial mixin or not-mixin node
 216      * @param level current nodes level
 217      * @param qualifiedName qname of initial node
 218      * @return {@link DataSchemaContextNode}
 219      */
 220     @Nullable
 221     private static DataSchemaContextNode<?> resolveMixinNode(@Nullable final DataSchemaContextNode<?> node,
 222                                                              @Nonnull final Set<QName> level,
 223                                                              @Nonnull final QName qualifiedName) {
 224         DataSchemaContextNode<?> currentNode = node;
 225         while (currentNode != null && currentNode.isMixin()) {
 226             level.add(qualifiedName);
 227             currentNode = currentNode.getChild(qualifiedName);
 228         }
 229
 230         return currentNode;
 231     }
 232
 233     /**
 234      * Find position of matching parenthesis increased by one, but at most equals to input size.
 235      * @param input input where to find for closing parenthesis
 236      * @return int position of closing parenthesis increased by one
 237      */
 238     private static int findClosingParenthesis(@Nonnull final String input) {
 239         int position = 0;
 240         int count = 1;
 241
 242         while (position < input.length()) {
 243             final char currentChar = input.charAt(position);
 244
 245             if (currentChar == STARTING_PARENTHESIS) {
 246                 count++;
 247             }
 248
 249             if (currentChar == CLOSING_PARENTHESIS) {
 250                 count--;
 251             }
 252
 253             if (count == 0) {
 254                 break;
 255             }
 256
 257             position++;
 258         }
 259
 260         // closing parenthesis was not found
 261         if (position >= input.length()) {
 262             throw new RestconfDocumentedException("Missing closing parenthesis in fields parameter",
 263                     ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 264         }
 265
 266         return ++position;
 267     }
 268 }