mattyb149 commented on a change in pull request #4785: URL: https://github.com/apache/nifi/pull/4785#discussion_r565395864
########## File path: nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/windowsevent/WindowsEventLogRecordReader.java ########## @@ -0,0 +1,626 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.nifi.windowsevent; + +import org.apache.nifi.logging.ComponentLog; +import org.apache.nifi.schema.inference.TimeValueInference; +import org.apache.nifi.serialization.MalformedRecordException; +import org.apache.nifi.serialization.RecordReader; +import org.apache.nifi.serialization.SimpleRecordSchema; +import org.apache.nifi.serialization.record.DataType; +import org.apache.nifi.serialization.record.MapRecord; +import org.apache.nifi.serialization.record.Record; +import org.apache.nifi.serialization.record.RecordField; +import org.apache.nifi.serialization.record.RecordFieldType; +import org.apache.nifi.serialization.record.RecordSchema; +import org.apache.nifi.serialization.record.type.ArrayDataType; +import org.apache.nifi.serialization.record.type.MapDataType; +import org.apache.nifi.serialization.record.type.RecordDataType; +import org.apache.nifi.serialization.record.util.DataTypeUtils; +import org.apache.nifi.stream.io.NonCloseableInputStream; +import org.apache.nifi.util.StringUtils; +import org.apache.nifi.xml.inference.XmlSchemaInference; + +import javax.xml.stream.XMLEventReader; +import javax.xml.stream.XMLInputFactory; +import javax.xml.stream.XMLStreamException; +import javax.xml.stream.events.Attribute; +import javax.xml.stream.events.Characters; +import javax.xml.stream.events.StartElement; +import javax.xml.stream.events.XMLEvent; +import java.io.FilterInputStream; +import java.io.IOException; +import java.io.InputStream; +import java.text.DateFormat; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashMap; +import java.util.Iterator; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.function.Supplier; + +public class WindowsEventLogRecordReader implements RecordReader { + + private final ComponentLog logger; + private final RecordSchema schema; + private boolean isArray = false; + private XMLEventReader xmlEventReader; + + private StartElement currentRecordStartTag; + // Utility used to infer <Data> tag data types + private final XmlSchemaInference xmlSchemaInference; + + private final Supplier<DateFormat> LAZY_DATE_FORMAT; + private final Supplier<DateFormat> LAZY_TIME_FORMAT; + private final Supplier<DateFormat> LAZY_TIMESTAMP_FORMAT; + + + public WindowsEventLogRecordReader(InputStream in, final String dateFormat, final String timeFormat, final String timestampFormat, ComponentLog logger) + throws IOException, MalformedRecordException { + + this.logger = logger; + + final DateFormat df = dateFormat == null ? null : DataTypeUtils.getDateFormat(dateFormat); + final DateFormat tf = timeFormat == null ? null : DataTypeUtils.getDateFormat(timeFormat); + final DateFormat tsf = timestampFormat == null ? null : DataTypeUtils.getDateFormat(timestampFormat); + + LAZY_DATE_FORMAT = () -> df; + LAZY_TIME_FORMAT = () -> tf; + LAZY_TIMESTAMP_FORMAT = () -> tsf; + + FilterInputStream inputStream; + try { + final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance(); + // Avoid XXE Vulnerabilities + xmlInputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, false); + xmlInputFactory.setProperty("javax.xml.stream.isSupportingExternalEntities", false); + + inputStream = new NonCloseableInputStream(in); + inputStream.mark(Integer.MAX_VALUE); + xmlEventReader = xmlInputFactory.createXMLEventReader(inputStream); + xmlSchemaInference = new XmlSchemaInference(new TimeValueInference(dateFormat, timeFormat, timestampFormat)); + + // Do a streaming pass through the input looking for <Data> tags, then reset the input + schema = determineSchema(); + + // Restart the XML event stream and advance to the first Event tag + inputStream.reset(); + xmlEventReader = xmlInputFactory.createXMLEventReader(inputStream); + if (isArray) { + skipToNextStartTag(); + } + setNextRecordStartTag(); + } catch (XMLStreamException e) { + throw new MalformedRecordException("Could not parse XML", e); + } + } + + @Override + public Record nextRecord(final boolean coerceTypes, final boolean dropUnknownFields) throws IOException, MalformedRecordException { + if (currentRecordStartTag == null) { + return null; + } + try { + final Record record = parseRecord(currentRecordStartTag, this.schema, coerceTypes, dropUnknownFields); + setNextRecordStartTag(); + if (record != null) { + return record; + } else { + return new MapRecord(this.schema, Collections.emptyMap()); + } + } catch (XMLStreamException e) { + throw new MalformedRecordException("Could not parse XML", e); + } + } + + @Override + public RecordSchema getSchema() throws MalformedRecordException { + return schema; + } + + @Override + public void close() throws IOException { + try { + xmlEventReader.close(); + } catch (XMLStreamException e) { + logger.error("Unable to close XMLEventReader"); + } + } + + private RecordSchema determineSchema() throws XMLStreamException { + + setNextRecordStartTag(); + if (currentRecordStartTag == null) { + throw new XMLStreamException("No root tag found, must be one of <Events> or <Event>"); + } + + if (currentRecordStartTag.getName().getLocalPart().equals("Events")) { + isArray = true; + setNextRecordStartTag(); + } + + // If there was an <Events></Events> tag pair with no Events in it, use the default schema + if (currentRecordStartTag == null) { + return generateFullSchema(new SimpleRecordSchema(Collections.emptyList())); + } + + List<RecordField> dataFields = new ArrayList<>(); + List<String> dataFieldNames = new ArrayList<>(); + while (currentRecordStartTag != null) { + if (!currentRecordStartTag.getName().getLocalPart().equals("Event")) { + // Unknown and invalid tag + throw new XMLStreamException("Expecting <Event> tag but found unknown/invalid tag " + currentRecordStartTag.getName().getLocalPart()); + } + + setNextRecordStartTag(); + // At an Event tag, skip the event log type tag (System, e.g.), go into EventData tag then add all the Data tags to the partial schema + while (currentRecordStartTag != null && !currentRecordStartTag.getName().getLocalPart().equals("EventData")) { + skipElement(); + setNextRecordStartTag(); + } + + if (currentRecordStartTag == null) { + throw new XMLStreamException("Expecting <EventData> tag but found none"); + } + + setNextRecordStartTag(); + if (currentRecordStartTag == null) { + // There was an <EventData></EventData> tag but no Data/Binary tags, so this record has been fully processed + continue; + } + + String eventDataElementName = currentRecordStartTag.getName().getLocalPart(); + while ("Data" .equals(eventDataElementName)) { + // Save reference to Data start element so we can continue to get the value/content + StartElement dataElement = currentRecordStartTag; + String content = getContent(); + + // Create field for the data point using attribute "Name" + String dataFieldName; + final Iterator<?> iterator = dataElement.getAttributes(); + if (!iterator.hasNext()) { + // If no Name attribute is provided, the Name is the content of the Data tag and there should be a following Binary tag + dataFieldName = content; + setNextRecordStartTag(); + eventDataElementName = currentRecordStartTag.getName().getLocalPart(); + if (!"Binary" .equals(eventDataElementName)) { + throw new XMLStreamException("Expecting <Binary> tag containing data for element: " + dataFieldName); + } + content = getContent(); + + } else { + final Attribute attribute = (Attribute) iterator.next(); + final String attributeName = attribute.getName().getLocalPart(); + if (!"Name" .equals(attributeName)) { + throw new XMLStreamException("Expecting 'Name' attribute, actual: " + attributeName); + } + dataFieldName = attribute.getValue(); + } + // Skip this if it has been processed in a previous record + if (!dataFieldNames.contains(dataFieldName)) { + final DataType dataElementDataType = xmlSchemaInference.inferTextualDataType(content); + RecordField newRecordField = new RecordField(dataFieldName, dataElementDataType, true); + dataFields.add(newRecordField); + dataFieldNames.add(dataFieldName); + } + + // Advance to next data point (or end of EventData) + setNextRecordStartTag(); + eventDataElementName = currentRecordStartTag == null ? null : currentRecordStartTag.getName().getLocalPart(); + } + } + + return generateFullSchema(new SimpleRecordSchema(dataFields)); + } + + private void skipElement() throws XMLStreamException { + while (xmlEventReader.hasNext()) { + final XMLEvent xmlEvent = xmlEventReader.nextEvent(); + + if (xmlEvent.isStartElement()) { + skipElement(); + } + if (xmlEvent.isEndElement()) { + return; + } + } + } + + private void skipToNextStartTag() throws XMLStreamException { + while (xmlEventReader.hasNext()) { + final XMLEvent xmlEvent = xmlEventReader.nextEvent(); + if (xmlEvent.isStartElement()) { + return; + } + } + } + + private void setNextRecordStartTag() throws XMLStreamException { + while (xmlEventReader.hasNext()) { + final XMLEvent xmlEvent = xmlEventReader.nextEvent(); + if (xmlEvent.isStartElement()) { + currentRecordStartTag = xmlEvent.asStartElement(); + return; + } + } + currentRecordStartTag = null; + } + + private RecordSchema generateFullSchema(final RecordSchema dataElementsSchema) { + final SimpleRecordSchema rootSchema; + + // Generate the full (input) schema even if the output schema is flattened + List<RecordField> systemProviderFields = new ArrayList<>(); + systemProviderFields.add(new RecordField("Guid", RecordFieldType.STRING.getDataType(), false)); Review comment: Yes I should be able to do all of the RecordFields except the Data tags statically ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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