--- /dev/null
+/*
+ * Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.restconf.nb.rfc8040.utils.parser;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import org.eclipse.jdt.annotation.NonNull;
+import org.opendaylight.restconf.common.context.InstanceIdentifierContext;
+import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
+import org.opendaylight.restconf.nb.rfc8040.FieldsParam;
+import org.opendaylight.restconf.nb.rfc8040.FieldsParam.NodeSelector;
+import org.opendaylight.yangtools.yang.common.ErrorTag;
+import org.opendaylight.yangtools.yang.common.ErrorType;
+import org.opendaylight.yangtools.yang.common.QName;
+import org.opendaylight.yangtools.yang.common.QNameModule;
+import org.opendaylight.yangtools.yang.data.util.DataSchemaContextNode;
+import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
+import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
+
+/**
+ * Utilities used for parsing of fields query parameter content.
+ *
+ * @param <T> type of identifier
+ */
+public abstract class AbstractFieldsTranslator<T> {
+ AbstractFieldsTranslator() {
+ // Hidden on purpose
+ }
+
+ /**
+ * Parse fields parameter and return complete list of child nodes organized into levels.
+ *
+ * @param identifier identifier context created from request URI
+ * @param input input value of fields parameter
+ * @return {@link List} of levels; each level contains {@link Set} of identifiers of type {@link T}
+ */
+ protected final @NonNull List<Set<T>> parseFields(final @NonNull InstanceIdentifierContext<?> identifier,
+ final @NonNull FieldsParam input) {
+ final DataSchemaContextNode<?> startNode = DataSchemaContextNode.fromDataSchemaNode(
+ (DataSchemaNode) identifier.getSchemaNode());
+
+ if (startNode == null) {
+ throw new RestconfDocumentedException(
+ "Start node missing in " + input, ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
+ }
+
+ final List<Set<T>> parsed = new ArrayList<>();
+ processSelectors(parsed, identifier.getSchemaContext(), identifier.getSchemaNode().getQName().getModule(),
+ startNode, input.nodeSelectors());
+ return parsed;
+ }
+
+ /**
+ * Add parsed child of current node to result for current level.
+ *
+ * @param currentNode current node
+ * @param childQName parsed identifier of child node
+ * @param level current nodes level
+ * @return {@link DataSchemaContextNode}
+ */
+ protected abstract @NonNull DataSchemaContextNode<?> addChildToResult(@NonNull DataSchemaContextNode<?> currentNode,
+ @NonNull QName childQName, @NonNull Set<T> level);
+
+ private void processSelectors(final List<Set<T>> parsed, final EffectiveModelContext context,
+ final QNameModule startNamespace, final DataSchemaContextNode<?> startNode,
+ final List<NodeSelector> selectors) {
+ final Set<T> startLevel = new HashSet<>();
+ parsed.add(startLevel);
+
+ for (var selector : selectors) {
+ var node = startNode;
+ var namespace = startNamespace;
+ var level = startLevel;
+
+
+ // Note: path is guaranteed to have at least one step
+ final var it = selector.path().iterator();
+ while (true) {
+ // FIXME: The layout of this loop is rather weird, which is due to how prepareQNameLevel() operates. We
+ // need to call it only when we know there is another identifier coming, otherwise we would end
+ // up with empty levels sneaking into the mix.
+ //
+ // Dealing with that weirdness requires understanding what the expected end results are and a
+ // larger rewrite of the algorithms involved.
+ final var step = it.next();
+ final var module = step.module();
+ if (module != null) {
+ // FIXME: this is not defensive enough, as we can fail to find the module
+ namespace = context.findModules(module).iterator().next().getQNameModule();
+ }
+
+ // add parsed identifier to results for current level
+ node = addChildToResult(node, step.identifier().bindTo(namespace), level);
+ if (!it.hasNext()) {
+ break;
+ }
+
+ // go one level down
+ level = prepareQNameLevel(parsed, level);
+ }
+
+ final var subs = selector.subSelectors();
+ if (!subs.isEmpty()) {
+ processSelectors(parsed, context, namespace, node, subs);
+ }
+ }
+ }
+
+ /**
+ * Preparation of the identifiers level that is used as storage for parsed identifiers. If the current level exist
+ * at the index that doesn't equal to the last index of already parsed identifiers, a new level of identifiers
+ * is allocated and pushed to input parsed identifiers.
+ *
+ * @param parsedIdentifiers Already parsed list of identifiers grouped to multiple levels.
+ * @param currentLevel Current level of identifiers (set).
+ * @return Existing or new level of identifiers.
+ */
+ private Set<T> prepareQNameLevel(final List<Set<T>> parsedIdentifiers, final Set<T> currentLevel) {
+ final Optional<Set<T>> existingLevel = parsedIdentifiers.stream()
+ .filter(qNameSet -> qNameSet.equals(currentLevel))
+ .findAny();
+ if (existingLevel.isPresent()) {
+ final int index = parsedIdentifiers.indexOf(existingLevel.get());
+ if (index == parsedIdentifiers.size() - 1) {
+ final Set<T> nextLevel = new HashSet<>();
+ parsedIdentifiers.add(nextLevel);
+ return nextLevel;
+ }
+
+ return parsedIdentifiers.get(index + 1);
+ }
+
+ final Set<T> nextLevel = new HashSet<>();
+ parsedIdentifiers.add(nextLevel);
+ return nextLevel;
+ }
+}
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Code Review / netconf.git / blobdiff