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