drill-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From jaltekruse <...@git.apache.org>
Subject [GitHub] drill pull request: Drill 3878: XML support in Apache Drill
Date Thu, 07 Apr 2016 16:43:12 GMT
Github user jaltekruse commented on a diff in the pull request:

    --- Diff: contrib/storage-xml/src/main/java/org/apache/drill/exec/store/easy/xml/XMLRecordReader.java
    @@ -0,0 +1,95 @@
    + * 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.drill.exec.store.easy.xml;
    +import com.fasterxml.jackson.annotation.JsonInclude;
    +import com.fasterxml.jackson.databind.JsonNode;
    +import com.fasterxml.jackson.databind.ObjectMapper;
    +import org.apache.drill.common.exceptions.ExecutionSetupException;
    +import org.apache.drill.common.exceptions.UserException;
    +import org.apache.drill.common.expression.SchemaPath;
    +import org.apache.drill.exec.exception.OutOfMemoryException;
    +import org.apache.drill.exec.ops.FragmentContext;
    +import org.apache.drill.exec.ops.OperatorContext;
    +import org.apache.drill.exec.physical.impl.OutputMutator;
    +import org.apache.drill.exec.store.dfs.DrillFileSystem;
    +import org.apache.drill.exec.store.easy.json.JSONRecordReader;
    +import org.apache.hadoop.fs.FSDataInputStream;
    +import org.apache.hadoop.fs.Path;
    +import org.xml.sax.SAXException;
    +import javax.xml.parsers.ParserConfigurationException;
    +import javax.xml.parsers.SAXParser;
    +import javax.xml.parsers.SAXParserFactory;
    +import java.io.IOException;
    +import java.util.List;
    +public class XMLRecordReader extends JSONRecordReader {
    +    private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(XMLRecordReader.class);
    +    private XMLSaxParser handler;
    +    private SAXParser xmlParser;
    +    private JsonNode node;
    +    public XMLRecordReader(FragmentContext fragmentContext, String inputPath, DrillFileSystem
fileSystem, List<SchemaPath> columns, XMLFormatPlugin.XMLFormatConfig xmlConfig) throws
OutOfMemoryException {
    +        super(fragmentContext, inputPath, fileSystem, columns);
    +        try {
    +            FSDataInputStream fsStream = fileSystem.open(new Path(inputPath));
    +            SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
    +            xmlParser = saxParserFactory.newSAXParser();
    +            handler = new XMLSaxParser();
    +            handler.setRemoveNameSpace(!xmlConfig.getKeepPrefix());
    +            xmlParser.parse(fsStream.getWrappedStream(), handler);
    +            ObjectMapper mapper = new ObjectMapper();
    +            node = mapper.valueToTree(handler.getVal());
    --- End diff --
    Considering that Drill can be used to read very large JSON files, and presumably users
would expect to process similarly sized XML files, it probably makes sense to have this transformation
happen in a streaming fashion rather than loading the whole file into memory and transforming

If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.

View raw message