/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.query.xquery.saxon;
import java.io.IOException;
import java.io.InputStream;
import java.sql.SQLXML;
import java.util.Map;
import javax.xml.stream.XMLStreamException;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.stax.StAXSource;
import net.sf.saxon.Configuration;
import net.sf.saxon.event.FilterFactory;
import net.sf.saxon.event.ProxyReceiver;
import net.sf.saxon.event.Receiver;
import net.sf.saxon.evpull.PullEventSource;
import net.sf.saxon.evpull.StaxToEventBridge;
import net.sf.saxon.lib.AugmentedSource;
import net.sf.saxon.om.DocumentInfo;
import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.query.DynamicQueryContext;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.HexBinaryValue;
import nu.xom.Builder;
import nu.xom.DocType;
import nu.xom.Element;
import nu.xom.Node;
import nu.xom.Nodes;
import nu.xom.ParsingException;
import nux.xom.xquery.StreamingPathFilter;
import nux.xom.xquery.StreamingTransform;
import org.teiid.core.types.BinaryType;
import org.teiid.query.function.source.XMLSystemFunctions;
import org.teiid.query.xquery.saxon.SaxonXQueryExpression.RowProcessor;
import org.teiid.runtime.client.Messages;
import org.teiid.runtime.client.TeiidClientException;
/**
* Used to isolate the xom/nux dependency and to better isolate the saxon processing logic.
*/
public class XQueryEvaluator {
private static Nodes NONE = new Nodes();
private static InputStream FAKE_IS = new InputStream() {
@Override
public int read() throws IOException {
return 0;
}
};
public static SaxonXQueryExpression.Result evaluateXQuery(final SaxonXQueryExpression xquery, Object context, Map<String, Object> parameterValues, final RowProcessor processor) throws Exception {
DynamicQueryContext dynamicContext = new DynamicQueryContext(xquery.config);
SaxonXQueryExpression.Result result = new SaxonXQueryExpression.Result();
try {
try {
for (Map.Entry<String, Object> entry : parameterValues.entrySet()) {
Object value = entry.getValue();
if(value instanceof SQLXML) {
value = XMLSystemFunctions.convertToSource(value);
result.sources.add((Source)value);
value = wrapStax((Source)value, xquery.getConfig());
} else if (value instanceof java.util.Date) {
value = XMLSystemFunctions.convertToAtomicValue(value);
} else if (value instanceof BinaryType) {
value = new HexBinaryValue(((BinaryType)value).getBytesDirect());
}
dynamicContext.setParameter(entry.getKey(), value);
}
} catch (TransformerException e) {
throw new TeiidClientException(e);
}
if (context != null) {
Source source = XMLSystemFunctions.convertToSource(context);
result.sources.add(source);
source = wrapStax(source, xquery.getConfig());
if (xquery.contextRoot != null) {
//create our own filter as this logic is not provided in the free saxon
AugmentedSource sourceInput = AugmentedSource.makeAugmentedSource(source);
sourceInput.addFilter(new FilterFactory() {
@Override
public ProxyReceiver makeFilter(Receiver arg0) {
return new PathMapFilter(xquery.contextRoot, arg0);
}
});
source = sourceInput;
//use streamable processing instead
if (xquery.streamingPath != null && processor != null) {
final StreamingTransform myTransform = new StreamingTransform() {
public Nodes transform(Element elem) {
processor.processRow(XQueryEvaluator.wrap(elem, xquery.config));
return NONE;
}
};
Builder builder = new Builder(new SaxonReader(xquery.config, sourceInput), false,
new StreamingPathFilter(xquery.streamingPath, xquery.namespaceMap).createNodeFactory(null, myTransform));
try {
//the builder is hard wired to parse the source, but the api will throw an exception if the stream is null
builder.build(FAKE_IS);
return result;
} catch (ParsingException e) {
throw new TeiidClientException(e, Messages.gs(Messages.TEIID.TEIID30151));
}
}
}
DocumentInfo doc;
try {
doc = xquery.config.buildDocument(source);
} catch (XPathException e) {
throw new TeiidClientException(e, Messages.gs(Messages.TEIID.TEIID30151));
}
dynamicContext.setContextItem(doc);
}
try {
result.iter = xquery.xQuery.iterator(dynamicContext);
return result;
} catch (TransformerException e) {
throw new TeiidClientException(e, Messages.gs(Messages.TEIID.TEIID30152));
}
} finally {
if (result.iter == null) {
result.close();
}
}
}
private static Source wrapStax(Source value, Configuration config) throws Exception {
if (value instanceof StAXSource) {
//saxon doesn't like staxsources
StaxToEventBridge sb = new StaxToEventBridge();
sb.setPipelineConfiguration(config.makePipelineConfiguration());
StAXSource staxSource = (StAXSource)value;
if (staxSource.getXMLEventReader() != null) {
try {
sb.setXMLStreamReader(new XMLEventStreamReader(staxSource.getXMLEventReader()));
} catch (XMLStreamException e) {
//should not happen as the StAXSource already peeked
throw new TeiidClientException(e);
}
} else {
sb.setXMLStreamReader(staxSource.getXMLStreamReader());
}
value = new PullEventSource(sb);
}
return value;
}
/**
* Converts a xom node into something readable by Saxon
* @param node
* @param config
* @return
*/
static NodeInfo wrap(Node node, Configuration config) {
if (node == null)
throw new IllegalArgumentException("node must not be null"); //$NON-NLS-1$
if (node instanceof DocType)
throw new IllegalArgumentException("DocType can't be queried by XQuery/XPath"); //$NON-NLS-1$
Node root = node;
while (root.getParent() != null) {
root = root.getParent();
}
DocumentWrapper docWrapper = new DocumentWrapper(root, root.getBaseURI(), config);
return docWrapper.wrap(node);
}
}