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An OSGi bundle for Saxon-HE
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 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.functions;
import net.sf.saxon.Controller;
import net.sf.saxon.expr.*;
import net.sf.saxon.expr.parser.ExpressionTool;
import net.sf.saxon.expr.parser.ExpressionVisitor;
import net.sf.saxon.expr.parser.Optimizer;
import net.sf.saxon.expr.parser.PathMap;
import net.sf.saxon.expr.sort.DocumentOrderIterator;
import net.sf.saxon.expr.sort.LocalOrderComparer;
import net.sf.saxon.om.*;
import net.sf.saxon.pattern.AnyNodeTest;
import net.sf.saxon.trans.KeyDefinitionSet;
import net.sf.saxon.trans.KeyManager;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.tree.iter.EmptyIterator;
import net.sf.saxon.type.Type;
import net.sf.saxon.value.AtomicValue;
import net.sf.saxon.value.Cardinality;
import net.sf.saxon.value.StringValue;
public class Idref extends SystemFunctionCall implements Callable {
private KeyDefinitionSet idRefKey;
/**
* Simplify: add a second implicit argument, the context document
* @param visitor an expression visitor
*/
/*@NotNull*/
public Expression simplify(ExpressionVisitor visitor) throws XPathException {
Idref f = (Idref)super.simplify(visitor);
f.addContextDocumentArgument(1, "idref");
return f;
}
/**
* Type-check the expression. This also calls preEvaluate() to evaluate the function
* if all the arguments are constant; functions that do not require this behavior
* can override the preEvaluate method.
*/
/*@NotNull*/
public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException {
Expression e = super.typeCheck(visitor, contextItemType);
idRefKey = visitor.getExecutable().getKeyManager().getKeyDefinitionSet(
StandardNames.getStructuredQName(StandardNames.XS_IDREFS));
return e;
}
public void checkArguments(/*@NotNull*/ ExpressionVisitor visitor) throws XPathException {
super.checkArguments(visitor);
Optimizer opt = visitor.getConfiguration().obtainOptimizer();
argument[0] = ExpressionTool.unsorted(opt, argument[0], false);
}
/**
* Get the static properties of this expression (other than its type). The result is
* bit-signficant. These properties are used for optimizations. In general, if
* property bit is set, it is true, but if it is unset, the value is unknown.
*/
public int computeSpecialProperties() {
int prop = StaticProperty.ORDERED_NODESET |
StaticProperty.SINGLE_DOCUMENT_NODESET |
StaticProperty.NON_CREATIVE;
if ((getNumberOfArguments() == 1) ||
(argument[1].getSpecialProperties() & StaticProperty.CONTEXT_DOCUMENT_NODESET) != 0) {
prop |= StaticProperty.CONTEXT_DOCUMENT_NODESET;
}
return prop;
}
/**
* preEvaluate: this method suppresses compile-time evaluation by doing nothing
* @param visitor an expression visitor
*/
public Expression preEvaluate(ExpressionVisitor visitor) {
return this;
}
/**
* Copy an expression. This makes a deep copy.
*
* @return the copy of the original expression
*/
/*@NotNull*/
public Expression copy() {
Idref i2 = (Idref)super.copy();
i2.idRefKey = idRefKey;
return i2;
}
/**
* Add a representation of a doc() call or similar function to a PathMap.
* This is a convenience method called by the addToPathMap() methods for doc(), document(), collection()
* and similar functions. These all create a new root expression in the path map.
*
* @param pathMap the PathMap to which the expression should be added
* @param pathMapNodeSet
* @return the pathMapNode representing the focus established by this expression, in the case where this
* expression is the first operand of a path expression or filter expression
*/
public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet) {
argument[0].addToPathMap(pathMap, pathMapNodeSet);
PathMap.PathMapNodeSet target = argument[1].addToPathMap(pathMap, pathMapNodeSet);
// indicate that the function navigates to all nodes in the document
target = target.createArc(AxisInfo.DESCENDANT, AnyNodeTest.getInstance());
return target;
}
/**
* Enumerate the results of the expression
*/
/*@NotNull*/
public SequenceIterator iterate(XPathContext context) throws XPathException {
Controller controller = context.getController();
assert controller != null;
NodeInfo arg2 = (NodeInfo)argument[1].evaluateItem(context);
assert arg2 != null;
arg2 = arg2.getRoot();
if (arg2.getNodeKind() != Type.DOCUMENT) {
dynamicError("In the idref() function," +
" the tree being searched must be one whose root is a document node", "FODC0001", context);
return EmptyIterator.emptyIterator();
}
DocumentInfo doc = (DocumentInfo)arg2;
// If the argument is a singleton, we evaluate the function
// directly; otherwise we recurse to evaluate it once for each Item
// in the sequence.
Expression expression = argument[0];
if (Cardinality.allowsMany(expression.getCardinality())) {
SequenceIterator keys = argument[0].iterate(context);
return getIdrefMultiple(doc, keys, context);
} else {
AtomicValue keyValue = (AtomicValue)argument[0].evaluateItem(context);
if (keyValue == null) {
return EmptyIterator.emptyIterator();
}
KeyManager keyManager = controller.getKeyManager();
return keyManager.selectByKey(idRefKey, doc, keyValue, context);
}
}
/**
* Get the result when multiple idref values are supplied. Note this is also called from
* compiled XQuery code.
* @param doc the document to be searched
* @param keys the idref values supplied
* @param context the dynamic execution context
* @return iterator over the result of the function
* @throws XPathException if a dynamic error occurs
*/
public static SequenceIterator getIdrefMultiple(DocumentInfo doc, SequenceIterator keys, XPathContext context)
throws XPathException {
IdrefMappingFunction map = new IdrefMappingFunction();
map.document = doc;
map.keyContext = context;
map.keyManager = context.getController().getKeyManager();
map.keySet = map.keyManager.getKeyDefinitionSet(StandardNames.getStructuredQName(StandardNames.XS_IDREFS));
SequenceIterator allValues = new MappingIterator(keys, map);
return new DocumentOrderIterator(allValues, LocalOrderComparer.getInstance());
}
/**
* Evaluate the expression
*
*
*
* @param context the dynamic evaluation context
* @param arguments the values of the arguments, supplied as SequenceIterators
* @return the result of the evaluation, in the form of a SequenceIterator
* @throws net.sf.saxon.trans.XPathException
* if a dynamic error occurs during the evaluation of the expression
*/
public Sequence call(XPathContext context, Sequence[] arguments) throws XPathException {
NodeInfo start = (arguments.length == 1 ? getContextNode(context) : (NodeInfo)arguments[1].head());
NodeInfo arg2 = start.getRoot();
if (arg2.getNodeKind() != Type.DOCUMENT) {
dynamicError("In the idref() function," +
" the tree being searched must be one whose root is a document node", "FODC0001", context);
return null;
}
DocumentInfo doc = (DocumentInfo)arg2;
return SequenceTool.toLazySequence(getIdrefMultiple(doc, arguments[0].iterate(), context));
}
private static class IdrefMappingFunction implements MappingFunction {
public DocumentInfo document;
public XPathContext keyContext;
public KeyManager keyManager;
public KeyDefinitionSet keySet;
/**
* Implement the MappingFunction interface
*/
public SequenceIterator map(StringValue item) throws XPathException {
KeyManager keyManager = keyContext.getController().getKeyManager();
return keyManager.selectByKey(keySet, document, item, keyContext);
}
}
}