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The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2022 Saxonica Limited
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.s9api;
import net.sf.saxon.Configuration;
import net.sf.saxon.event.PipelineConfiguration;
import net.sf.saxon.query.XQueryExpression;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.transpile.CSharpModifiers;
/**
* An XQueryExecutable represents the compiled form of a query.
* To execute the query, it must first be loaded to form an {@link net.sf.saxon.s9api.XQueryEvaluator}.
* An XQueryExecutable is immutable, and therefore thread-safe.
* It is simplest to load a new XQueryEvaluator each time the query is to be run.
* However, the XQueryEvaluator is serially reusable within a single thread.
* An XQueryExecutable is created by using one of the compile methods on the
* {@link net.sf.saxon.s9api.XQueryCompiler} class.
*
* @since 9.0
*/
@CSharpModifiers(code = {"internal"})
public class XQueryExecutable {
Processor processor;
XQueryExpression exp;
protected XQueryExecutable(Processor processor, XQueryExpression exp) {
this.processor = processor;
this.exp = exp;
}
/**
* Load the stylesheet to prepare it for execution.
*
* @return An XsltTransformer. The returned XsltTransformer can be used to set up the
* dynamic context for stylesheet evaluation, and to run the stylesheet.
*/
public XQueryEvaluator load() {
return new XQueryEvaluator(processor, exp);
}
/**
* Get the ItemType of the items in the result of the query, as determined by static analysis. This
* is the most precise ItemType that the processor is able to determine from static examination of the
* query; the actual items in the query result are guaranteed to belong to this ItemType or to a subtype
* of this ItemType.
*
* @return the statically-determined ItemType of the result of the query
* @since 9.1
*/
public ItemType getResultItemType() {
net.sf.saxon.type.ItemType it = exp.getExpression().getItemType();
return new ConstructedItemType(it, processor.getUnderlyingConfiguration());
}
/**
* Get the statically-determined cardinality of the result of the query. This is the most precise cardinality
* that the processor is able to determine from static examination of the query.
*
* @return the statically-determined cardinality of the result of the query
* @since 9.1
*/
/*@NotNull*/
public OccurrenceIndicator getResultCardinality() {
int card = exp.getExpression().getCardinality();
return OccurrenceIndicator.getOccurrenceIndicator(card);
}
/**
* Ask whether the query is an updating query: that is, whether it returns a Pending Update List
* rather than a Value. Note that queries using the XUpdate copy-modify syntax are not considered
* to be updating queries.
*
* @return true if the query is an updating query, false if not
* @since 9.1
*/
public boolean isUpdateQuery() {
return exp.isUpdateQuery();
}
/**
* Produce a diagnostic representation of the compiled query, in XML form.
* The detailed form of this representation is not stable (or even documented).
*
* @param destination the destination for the XML document containing the diagnostic representation
* of the compiled stylesheet
* @throws SaxonApiException if an error is detected
* @since 9.6
*/
public void explain(Destination destination) throws SaxonApiException {
Configuration config = processor.getUnderlyingConfiguration();
try {
PipelineConfiguration pipe = config.makePipelineConfiguration();
exp.explain(new ExpressionPresenter(config, destination.getReceiver(pipe, config.obtainDefaultSerializationProperties())));
} catch (XPathException e) {
throw new SaxonApiException(e);
}
}
/**
* Get the underlying implementation object representing the compiled stylesheet. This provides
* an escape hatch into lower-level APIs. The object returned by this method may change from release
* to release.
*
* @return the underlying implementation of the compiled stylesheet
*/
public XQueryExpression getUnderlyingCompiledQuery() {
return exp;
}
}