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SirixDB is a hybrid on-disk and in-memory document oriented, versioned database system. It has a lightweight buffer manager, stores everything in a huge persistent and durable tree and allows efficient reconstruction of every revision. Furthermore, SirixDB implements change tracking, diffing and supports time travel queries.
/**
* Copyright (c) 2011, University of Konstanz, Distributed Systems Group All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted
* provided that the following conditions are met: * Redistributions of source code must retain the
* above copyright notice, this list of conditions and the following disclaimer. * Redistributions
* in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* * Neither the name of the University of Konstanz nor the names of its contributors may be used to
* endorse or promote products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package io.sirix.service.xml.shredder;
import io.sirix.access.DatabaseConfiguration;
import io.sirix.access.Databases;
import io.sirix.access.ResourceConfiguration;
import io.sirix.api.xml.XmlNodeTrx;
import io.sirix.api.xml.XmlResourceSession;
import io.sirix.exception.SirixException;
import io.sirix.exception.SirixIOException;
import io.sirix.node.xml.ElementNode;
import io.sirix.service.InsertPosition;
import io.sirix.service.ShredderCommit;
import io.sirix.settings.Constants;
import io.sirix.utils.LogWrapper;
import io.brackit.query.atomic.QNm;
import org.slf4j.LoggerFactory;
import javax.xml.namespace.QName;
import javax.xml.stream.*;
import javax.xml.stream.events.*;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Iterator;
import java.util.Queue;
import java.util.concurrent.Callable;
import static java.util.Objects.requireNonNull;
/**
* This class appends a given {@link XMLStreamReader} to a {@link XmlNodeTrx} . The content of the
* stream is added as a subtree. Based on an enum which identifies the point of insertion, the
* subtree is either added as first child or as right sibling.
*
* @author Marc Kramis, Seabix
* @author Sebastian Graf, University of Konstanz
* @author Johannes Lichtenberger, University of Konstanz
*
*/
public final class XmlShredder extends AbstractShredder implements Callable {
/** {@link LogWrapper} reference. */
private static final LogWrapper LOGWRAPPER = new LogWrapper(LoggerFactory.getLogger(XmlShredder.class));
/** {@link XmlNodeTrx}. */
private final XmlNodeTrx wtx;
/** {@link XMLEventReader}. */
private final XMLEventReader reader;
/** Determines if changes are going to be commit right after shredding. */
private final ShredderCommit commit;
/** Insertion position. */
private final InsertPosition insert;
/** Determines if comments should be included. */
private final boolean includeComments;
/** Determines if processing instructions should be included. */
private final boolean includePIs;
/**
* Builder to build an {@link XmlShredder} instance.
*/
public static class Builder {
/** {@link XmlNodeTrx} implementation. */
private final XmlNodeTrx wtx;
/** {@link XMLEventReader} implementation. */
private final XMLEventReader reader;
/** Insertion position. */
private final InsertPosition insert;
/** Determines if comments should be included. */
private boolean includeComments = true;
/** Determines if processing instructions should be included. */
private boolean includePIs = true;
/**
* Determines if after shredding the transaction should be immediately commited.
*/
private ShredderCommit commit = ShredderCommit.NOCOMMIT;
/**
* Constructor.
*
* @param wtx {@link XmlNodeTrx} implementation
* @param reader {@link XMLEventReader} implementation
* @param insert insertion position
*/
public Builder(final XmlNodeTrx wtx, final XMLEventReader reader, final InsertPosition insert) {
this.wtx = requireNonNull(wtx);
this.reader = requireNonNull(reader);
this.insert = requireNonNull(insert);
}
/**
* Include comments or not (default: yes).
*
* @param include include comments
* @return this builder instance
*/
public Builder includeComments(final boolean include) {
includeComments = include;
return this;
}
/**
* Include processing instructions or not (default: yes).
*
* @param include processing instructions
* @return this builder instance
*/
public Builder includePIs(final boolean include) {
includePIs = include;
return this;
}
/**
* Commit afterwards.
*
* @return this builder instance
*/
public Builder commitAfterwards() {
commit = ShredderCommit.COMMIT;
return this;
}
/**
* Build an instance.
*
* @return {@link XmlShredder} instance
*/
public XmlShredder build() {
return new XmlShredder(this);
}
}
/**
* Private constructor.
*
* @param builder builder reference
*/
private XmlShredder(final Builder builder) {
super(builder.wtx, builder.insert);
wtx = builder.wtx;
reader = builder.reader;
insert = builder.insert;
includeComments = builder.includeComments;
includePIs = builder.includePIs;
commit = builder.commit;
}
/**
* Invoking the shredder.
*
* @throws SirixException if any kind of sirix exception which has occured
* @return revision of file
*/
@Override
public Long call() {
final long revision = wtx.getRevisionNumber();
insertNewContent();
commit.commit(wtx);
return revision;
}
/**
* Insert new content based on a StAX parser {@link XMLStreamReader}.
*
* @throws SirixException if something went wrong while inserting
*/
private void insertNewContent() {
try {
boolean firstElement = true;
int level = 0;
QName rootElement = null;
boolean endElemReached = false;
final StringBuilder sBuilder = new StringBuilder();
long insertedRootNodeKey = -1;
// Iterate over all nodes.
while (reader.hasNext() && !endElemReached) {
final XMLEvent event = reader.nextEvent();
switch (event.getEventType()) {
case XMLStreamConstants.START_ELEMENT:
level++;
addNewElement(event.asStartElement());
if (firstElement) {
firstElement = false;
insertedRootNodeKey = wtx.getNodeKey();
rootElement = event.asStartElement().getName();
}
break;
case XMLStreamConstants.END_ELEMENT:
level--;
if (level == 0 && rootElement != null && rootElement.equals(event.asEndElement().getName())) {
endElemReached = true;
}
final QName name = event.asEndElement().getName();
processEndTag(new QNm(name.getNamespaceURI(), name.getPrefix(), name.getLocalPart()));
break;
case XMLStreamConstants.CHARACTERS:
if (reader.peek().getEventType() == XMLStreamConstants.CHARACTERS) {
sBuilder.append(event.asCharacters().getData().trim());
} else {
sBuilder.append(event.asCharacters().getData().trim());
processText(sBuilder.toString());
sBuilder.setLength(0);
}
break;
case XMLStreamConstants.COMMENT:
if (includeComments) {
processComment(((Comment) event).getText());
}
break;
case XMLStreamConstants.PROCESSING_INSTRUCTION:
if (includePIs) {
final ProcessingInstruction pi = (ProcessingInstruction) event;
processPI(pi.getData(), pi.getTarget());
}
break;
default:
// Node kind not known.
}
}
wtx.moveTo(insertedRootNodeKey);
} catch (final XMLStreamException e) {
throw new SirixIOException(e);
}
}
/**
* Add a new element node.
*
* @param event the current event from the StAX parser
* @throws SirixException if adding {@link ElementNode} fails
*/
private void addNewElement(final StartElement event) throws SirixException {
assert event != null;
final QName qName = event.getName();
final QNm name = new QNm(qName.getNamespaceURI(), qName.getPrefix(), qName.getLocalPart());
processStartTag(name);
// Parse namespaces.
for (final Iterator it = event.getNamespaces(); it.hasNext();) {
final Namespace namespace = (Namespace) it.next();
wtx.insertNamespace(new QNm(namespace.getNamespaceURI(), namespace.getPrefix(), ""));
wtx.moveToParent();
}
// Parse attributes.
for (final Iterator it = event.getAttributes(); it.hasNext();) {
final Attribute attribute = (Attribute) it.next();
final QName attName = attribute.getName();
wtx.insertAttribute(new QNm(attName.getNamespaceURI(), attName.getPrefix(), attName.getLocalPart()),
attribute.getValue());
wtx.moveToParent();
}
}
/**
* Main method.
*
* @param args input and output files
* @throws XMLStreamException if the XML stream isn't valid
* @throws IOException if an I/O error occurs
* @throws SirixException if a Sirix error occurs
*/
public static void main(final String... args) throws SirixException, IOException, XMLStreamException {
if (args.length != 2 && args.length != 3) {
throw new IllegalArgumentException("Usage: XMLShredder XMLFile Database [true/false] (shredder comment|PI)");
}
LOGWRAPPER.info("Shredding '" + args[0] + "' to '" + args[1] + "' ... ");
final long time = System.nanoTime();
final Path target = Paths.get(args[1]);
final DatabaseConfiguration config = new DatabaseConfiguration(target);
Databases.removeDatabase(target);
Databases.createXmlDatabase(config);
try (final var db = Databases.openXmlDatabase(target)) {
db.createResource(new ResourceConfiguration.Builder("shredded").build());
try (final XmlResourceSession resMgr = db.beginResourceSession("shredded");
final XmlNodeTrx wtx = resMgr.beginNodeTrx();
final FileInputStream fis = new FileInputStream(Paths.get(args[0]).toFile())) {
final XMLEventReader reader = createFileReader(fis);
final boolean includeCoPI = args.length == 3 && Boolean.parseBoolean(args[2]);
final XmlShredder shredder =
new XmlShredder.Builder(wtx, reader, InsertPosition.AS_FIRST_CHILD).commitAfterwards()
.includeComments(includeCoPI)
.includePIs(includeCoPI)
.build();
shredder.call();
}
}
LOGWRAPPER.info(" done [" + (System.nanoTime() - time) / 1000000 + " ms].");
}
/**
* Create a new {@link XMLEventReader} instance on a file.
*
* @param fis the file input stream
* @return an {@link XMLEventReader}
* @throws SirixException if creating the xml event reader fails.
*/
public static XMLEventReader createFileReader(final FileInputStream fis) {
requireNonNull(fis);
final XMLInputFactory factory = XMLInputFactory.newInstance();
setProperties(factory);
try {
return factory.createXMLEventReader(fis);
} catch (XMLStreamException e) {
throw new SirixException(e.getMessage(), e);
}
}
private static void setProperties(final XMLInputFactory factory) {
factory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
factory.setProperty(XMLInputFactory.IS_REPLACING_ENTITY_REFERENCES, true);
}
/**
* Create a new {@link XMLEventReader} instance on a string.
*
* @param xmlString the XML file as a string to parse
* @return an {@link XMLEventReader}
* @throws SirixException if creating the xml event reader fails.
*/
public static XMLEventReader createStringReader(final String xmlString) {
requireNonNull(xmlString);
final XMLInputFactory factory = XMLInputFactory.newInstance();
setProperties(factory);
try {
final InputStream in = new ByteArrayInputStream(xmlString.getBytes(Constants.DEFAULT_ENCODING));
return factory.createXMLEventReader(in);
} catch (XMLStreamException e) {
throw new SirixException(e.getMessage(), e);
}
}
/**
* Create a new StAX reader based on a List of {@link XMLEvent}s.
*
* @param events {@link XMLEvent}s
* @return an {@link XMLEventReader}
* @throws IOException if I/O operation fails
* @throws XMLStreamException if any parsing error occurs
*/
public static XMLEventReader createQueueReader(final Queue events) throws IOException, XMLStreamException {
return new QueueEventReader(requireNonNull(events));
}
}
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