restconf/restconf-nb-rfc8040/src/main/java/org/opendaylight/restconf/nb/rfc8040/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.nb.rfc8040.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.nb.rfc8040.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 final 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     private ParserFieldsParameter() {
  36
  37     }
  38
  39     /**
  40      * Parse fields parameter and return complete list of child nodes organized into levels.
  41      * @param identifier identifier context created from request URI
  42      * @param input input value of fields parameter
  43      * @return {@link List}
  44      */
  45     @Nonnull
  46     public static List<Set<QName>> parseFieldsParameter(@Nonnull final InstanceIdentifierContext<?> identifier,
  47                                                         @Nonnull final String input) {
  48         final List<Set<QName>> parsed = new ArrayList<>();
  49         final SchemaContext context = identifier.getSchemaContext();
  50         final QNameModule startQNameModule = identifier.getSchemaNode().getQName().getModule();
  51         final DataSchemaContextNode<?> startNode = DataSchemaContextNode.fromDataSchemaNode(
  52                 (DataSchemaNode) identifier.getSchemaNode());
  53
  54         if (startNode == null) {
  55             throw new RestconfDocumentedException(
  56                     "Start node missing in " + input, ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
  57         }
  58
  59         parseInput(input, startQNameModule, startNode, parsed, context);
  60         return parsed;
  61     }
  62
  63     /**
  64      * Parse input value of fields parameter and create list of sets. Each set represents one level of child nodes.
  65      * @param input input value of fields parameter
  66      * @param startQNameModule starting qname module
  67      * @param startNode starting node
  68      * @param parsed list of results
  69      * @param context schema context
  70      */
  71     private static void parseInput(@Nonnull final String input,
  72                                    @Nonnull final QNameModule startQNameModule,
  73                                    @Nonnull final DataSchemaContextNode<?> startNode,
  74                                    @Nonnull final List<Set<QName>> parsed,
  75                                    @Nonnull final SchemaContext context) {
  76         int currentPosition = 0;
  77         int startPosition = 0;
  78         DataSchemaContextNode<?> currentNode = startNode;
  79         QNameModule currentQNameModule = startQNameModule;
  80
  81         Set<QName> currentLevel = new HashSet<>();
  82         parsed.add(currentLevel);
  83
  84         while (currentPosition < input.length()) {
  85             final char currentChar = input.charAt(currentPosition);
  86
  87             if (Deserializer.IDENTIFIER.matches(currentChar) || currentChar == '/') {
  88                 if (currentChar == SLASH) {
  89                     // add parsed identifier to results for current level
  90                     currentNode = addChildToResult(
  91                             currentNode,
  92                             input.substring(startPosition, currentPosition), currentQNameModule, currentLevel);
  93                     // go one level down
  94                     currentLevel = new HashSet<>();
  95                     parsed.add(currentLevel);
  96
  97                     currentPosition++;
  98                     startPosition = currentPosition;
  99                 } else {
 100                     currentPosition++;
 101                 }
 102
 103                 continue;
 104             }
 105
 106             switch (currentChar) {
 107                 case COLON :
 108                     // new namespace and revision found
 109                     currentQNameModule = context.findModules(
 110                             input.substring(startPosition, currentPosition)).iterator().next().getQNameModule();
 111                     currentPosition++;
 112                     break;
 113                 case STARTING_PARENTHESIS:
 114                     // add current child to parsed results for current level
 115                     final DataSchemaContextNode<?> child = addChildToResult(
 116                             currentNode,
 117                             input.substring(startPosition, currentPosition), currentQNameModule, currentLevel);
 118                     // call with child node as new start node for one level down
 119                     final int closingParenthesis = currentPosition
 120                             + findClosingParenthesis(input.substring(currentPosition + 1));
 121                     parseInput(
 122                             input.substring(currentPosition + 1, closingParenthesis),
 123                             currentQNameModule,
 124                             child,
 125                             parsed,
 126                             context);
 127
 128                     // closing parenthesis must be at the end of input or separator and one more character is expected
 129                     currentPosition = closingParenthesis + 1;
 130                     if (currentPosition != input.length()) {
 131                         if (currentPosition + 1 < input.length()) {
 132                             if (input.charAt(currentPosition) == SEMICOLON) {
 133                                 currentPosition++;
 134                             } else {
 135                                 throw new RestconfDocumentedException(
 136                                         "Missing semicolon character after "
 137                                                 + child.getIdentifier().getNodeType().getLocalName()
 138                                                 + " child nodes",
 139                                         ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 140                             }
 141                         } else {
 142                             throw new RestconfDocumentedException(
 143                                     "Unexpected character '"
 144                                             + input.charAt(currentPosition)
 145                                             + "' found in fields parameter value",
 146                                     ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 147                         }
 148                     }
 149
 150                     break;
 151                 case SEMICOLON:
 152                     // complete identifier found
 153                     addChildToResult(
 154                             currentNode,
 155                             input.substring(startPosition, currentPosition), currentQNameModule, currentLevel);
 156                     currentPosition++;
 157                     break;
 158                 default:
 159                     throw new RestconfDocumentedException(
 160                             "Unexpected character '" + currentChar + "' found in fields parameter value",
 161                             ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 162             }
 163
 164             startPosition = currentPosition;
 165         }
 166
 167         // parse input to end
 168         if (startPosition < input.length()) {
 169             addChildToResult(currentNode, input.substring(startPosition), currentQNameModule, currentLevel);
 170         }
 171     }
 172
 173     /**
 174      * Add parsed child of current node to result for current level.
 175      * @param currentNode current node
 176      * @param identifier parsed identifier of child node
 177      * @param currentQNameModule current namespace and revision in {@link QNameModule}
 178      * @param level current nodes level
 179      * @return {@link DataSchemaContextNode}
 180      */
 181     @Nonnull
 182     private static DataSchemaContextNode<?> addChildToResult(
 183             @Nonnull final DataSchemaContextNode<?> currentNode,
 184             @Nonnull final String identifier,
 185             @Nonnull final QNameModule currentQNameModule,
 186             @Nonnull final Set<QName> level) {
 187         final QName childQName = QName.create(currentQNameModule, identifier);
 188
 189         // resolve parent node
 190         final DataSchemaContextNode<?> parentNode = resolveMixinNode(
 191                 currentNode, level, currentNode.getIdentifier().getNodeType());
 192         if (parentNode == null) {
 193             throw new RestconfDocumentedException(
 194                     "Not-mixin node missing in " + currentNode.getIdentifier().getNodeType().getLocalName(),
 195                     ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 196         }
 197
 198         // resolve child node
 199         final DataSchemaContextNode<?> childNode = resolveMixinNode(
 200                 parentNode.getChild(childQName), level, childQName);
 201         if (childNode == null) {
 202             throw new RestconfDocumentedException(
 203                     "Child " + identifier + " node missing in "
 204                             + currentNode.getIdentifier().getNodeType().getLocalName(),
 205                     ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 206         }
 207
 208         // add final childNode node to level nodes
 209         level.add(childNode.getIdentifier().getNodeType());
 210         return childNode;
 211     }
 212
 213     /**
 214      * Resolve mixin node by searching for inner nodes until not mixin node or null is found.
 215      * All nodes expect of not mixin node are added to current level nodes.
 216      * @param node initial mixin or not-mixin node
 217      * @param level current nodes level
 218      * @param qualifiedName qname of initial node
 219      * @return {@link DataSchemaContextNode}
 220      */
 221     @Nullable
 222     private static DataSchemaContextNode<?> resolveMixinNode(@Nullable final DataSchemaContextNode<?> node,
 223                                                              @Nonnull final Set<QName> level,
 224                                                              @Nonnull final QName qualifiedName) {
 225         DataSchemaContextNode<?> currentNode = node;
 226         while (currentNode != null && currentNode.isMixin()) {
 227             level.add(qualifiedName);
 228             currentNode = currentNode.getChild(qualifiedName);
 229         }
 230
 231         return currentNode;
 232     }
 233
 234     /**
 235      * Find position of matching parenthesis increased by one, but at most equals to input size.
 236      * @param input input where to find for closing parenthesis
 237      * @return int position of closing parenthesis increased by one
 238      */
 239     private static int findClosingParenthesis(@Nonnull final String input) {
 240         int position = 0;
 241         int count = 1;
 242
 243         while (position < input.length()) {
 244             final char currentChar = input.charAt(position);
 245
 246             if (currentChar == STARTING_PARENTHESIS) {
 247                 count++;
 248             }
 249
 250             if (currentChar == CLOSING_PARENTHESIS) {
 251                 count--;
 252             }
 253
 254             if (count == 0) {
 255                 break;
 256             }
 257
 258             position++;
 259         }
 260
 261         // closing parenthesis was not found
 262         if (position >= input.length()) {
 263             throw new RestconfDocumentedException("Missing closing parenthesis in fields parameter",
 264                     ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 265         }
 266
 267         return ++position;
 268     }
 269 }