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 * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package org.openjdk.bench.javax.xml;

import org.openjdk.jmh.annotations.Benchmark;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.Node;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import java.io.ByteArrayInputStream;

import java.io.IOException;

public class DOM extends AbstractXMLMicro {

    @Benchmark

    public Document testBuild() throws Exception {

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

        byte[] bytes = getFileBytesFromResource(doc);

        InputSource source = new InputSource();

        ByteArrayInputStream bais = new ByteArrayInputStream(bytes);

        source.setByteStream(bais);

        return buildDocument(dbf, source);

    }

    @Benchmark

    public Document testModify() throws Exception {

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

        byte[] bytes = getFileBytesFromResource(doc);

        ByteArrayInputStream bais = new ByteArrayInputStream(bytes);

        InputSource source = new InputSource(bais);

        Document doc1 = buildDocument(dbf, source);

        modifyElementRecursive(doc1.getDocumentElement());

        return doc1;

    }

    @Benchmark

    public Document testWalk() throws Exception {

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

        byte[] bytes = getFileBytesFromResource(doc);

        ByteArrayInputStream bais = new ByteArrayInputStream(bytes);

        InputSource source = new InputSource(bais);

        Document doc1 = buildDocument(dbf, source);

        walkElementRecursive(doc1.getDocumentElement());

        return doc1;

    }

    private Document buildDocument(DocumentBuilderFactory dbf, InputSource source)

            throws ParserConfigurationException, SAXException, IOException {

        dbf.setValidating(false);

        dbf.setNamespaceAware(true);

        DocumentBuilder docBuilder = dbf.newDocumentBuilder();

        return docBuilder.parse(source);

    }

    // TODO Fix so it isn't recursive?

    private static void walkElementRecursive(Element element) {

        // loop through children

        if (element.hasChildNodes()) {

            Node child = element.getFirstChild();

            while (child != null) {

                // handle child by type

                int type = child.getNodeType();

                if (type == Node.ELEMENT_NODE) {

                    walkElementRecursive((Element) child);

                }

                child = child.getNextSibling();

            }

        }

    }

    // TODO Fix so it isn't recursive?

    private void modifyElementRecursive(Element element) {

        // check for children present

        if (element.hasChildNodes()) {

            // loop through child nodes

            boolean content = false;

            // Should not be null since we already have made a .hasChildNodes()

            // check.

            Node child = element.getFirstChild();

            do {

                // Handle child by node type.

                if (child.getNodeType() == Node.TEXT_NODE) {

                    String trimmed = child.getNodeValue().trim();

                    if (trimmed.length() == 0) {

                        // delete child if nothing but whitespace

                        element.removeChild(child);

                    } else {

                        // make sure we have the parent element information

                        content = true;

                        Document doc = element.getOwnerDocument();

                        String uri = element.getNamespaceURI();

                        String prefix = element.getPrefix();

                        content = true;

                        // Create a "text" element matching parent namespace.

                        Element text = (uri == null) ? doc.createElement("text") : doc.createElementNS(uri, prefix

                                + ":text");

                        // wrap the trimmed content with new element

                        text.appendChild(doc.createTextNode(trimmed));

                        element.replaceChild(text, child);

                    }

                } else if (child.getNodeType() == Node.ELEMENT_NODE) {

                    modifyElementRecursive((Element) child);

                }

            } while ((child = child.getNextSibling()) != null);

            // check if we've seen any non-whitespace content for element

            if (content) {

                String prefix = element.getPrefix();

                String uri = element.getNamespaceURI();

                // add attribute flagging content found

                if (prefix == null || prefix.length() == 0) {

                    element.setAttribute("text", "true");

                } else {

                    element.setAttributeNS(uri, prefix + ":text", "true");

                }

            }

        }

    }

}