--- /dev/null
+/*
+ * Copyright (c) 2020 PANTHEON.tech, s.r.o. 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.streams.listeners;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.time.OffsetDateTime;
+import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+import java.util.Optional;
+import javax.xml.XMLConstants;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpression;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+import org.eclipse.jdt.annotation.NonNull;
+import org.opendaylight.yangtools.concepts.Immutable;
+import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
+import org.w3c.dom.Document;
+
+abstract class EventFormatter<T> implements Immutable {
+ private static final XPathFactory XPF = XPathFactory.newInstance();
+
+ // FIXME: NETCONF-369: XPath operates without namespace context, therefore we need an namespace-unaware builder.
+ // Once it is fixed we can use UntrustedXML instead.
+ private static final @NonNull DocumentBuilderFactory DBF;
+
+ static {
+ final DocumentBuilderFactory f = DocumentBuilderFactory.newInstance();
+ f.setCoalescing(true);
+ f.setExpandEntityReferences(false);
+ f.setIgnoringElementContentWhitespace(true);
+ f.setIgnoringComments(true);
+ f.setXIncludeAware(false);
+ try {
+ f.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
+ f.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
+ f.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
+ f.setFeature("http://xml.org/sax/features/external-general-entities", false);
+ f.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
+ } catch (final ParserConfigurationException e) {
+ throw new ExceptionInInitializerError(e);
+ }
+ DBF = f;
+ }
+
+ private final XPathExpression filter;
+
+ EventFormatter() {
+ this.filter = null;
+ }
+
+ EventFormatter(final String xpathFilter) throws XPathExpressionException {
+ final XPath xpath;
+ synchronized (XPF) {
+ xpath = XPF.newXPath();
+ }
+ // FIXME: NETCONF-369: we need to bind the namespace context here and for that we need the SchemaContext
+ filter = xpath.compile(xpathFilter);
+ }
+
+ final Optional<String> eventData(final EffectiveModelContext schemaContext, final T input, final Instant now,
+ final boolean leafNodesOnly, final boolean skipData)
+ throws Exception {
+ if (!filterMatches(schemaContext, input, now)) {
+ return Optional.empty();
+ }
+ return Optional.of(createText(schemaContext, input, now, leafNodesOnly, skipData));
+ }
+
+ /**
+ * Export the provided input into the provided document so we can verify whether a filter matches the content.
+ *
+ * @param doc the document to fill
+ * @param schemaContext context to use for the export
+ * @param input data to export
+ * @throws IOException if any IOException occurs during export to the document
+ */
+ abstract void fillDocument(Document doc, EffectiveModelContext schemaContext, T input) throws IOException;
+
+ /**
+ * Format the input data into string representation of the data provided.
+ *
+ * @param schemaContext context to use for the export
+ * @param input input data
+ * @param now time the event happened
+ * @param leafNodesOnly option to include only leaves in the result
+ * @param skipData option to skip data in the result, only paths would be included
+ * @return String representation of the formatted data
+ * @throws Exception if the underlying formatters fail to export the data to the requested format
+ */
+ abstract String createText(EffectiveModelContext schemaContext, T input, Instant now, boolean leafNodesOnly,
+ boolean skipData) throws Exception;
+
+ private boolean filterMatches(final EffectiveModelContext schemaContext, final T input, final Instant now)
+ throws IOException {
+ if (filter == null) {
+ return true;
+ }
+
+ final Document doc;
+ try {
+ doc = DBF.newDocumentBuilder().newDocument();
+ } catch (final ParserConfigurationException e) {
+ throw new IOException("Failed to create a new document", e);
+ }
+ fillDocument(doc, schemaContext, input);
+
+ final Boolean eval;
+ try {
+ eval = (Boolean) filter.evaluate(doc, XPathConstants.BOOLEAN);
+ } catch (final XPathExpressionException e) {
+ throw new IllegalStateException("Failed to evaluate expression " + filter, e);
+ }
+
+ return eval;
+ }
+
+ /**
+ * Formats data specified by RFC3339.
+ *
+ * @param now time stamp
+ * @return Data specified by RFC3339.
+ */
+ static String toRFC3339(final Instant now) {
+ return DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(OffsetDateTime.ofInstant(now, ZoneId.systemDefault()));
+ }
+}
Code Review / netconf.git / blobdiff