package org.exist.xquery.modules.sort;
import org.exist.EXistException;
import org.exist.dom.NodeProxy;
import org.exist.dom.QName;
import org.exist.indexing.sort.SortIndex;
import org.exist.indexing.sort.SortIndexWorker;
import org.exist.util.LockException;
import org.exist.xquery.*;
import org.exist.xquery.value.*;
public class GetIndex extends BasicFunction {
public final static FunctionSignature signature =
new FunctionSignature(
new QName("index", SortModule.NAMESPACE_URI, SortModule.PREFIX),
"Look up a node in the sort index and return a number (> 0) corresponding to the " +
"position of that node in the ordered set which was created by a previous call to " +
"the sort:create-index function. The function returns the empty sequence if the node " +
"cannot be found in the index.",
new SequenceType[] {
new FunctionParameterSequenceType("id", Type.STRING, Cardinality.EXACTLY_ONE, "The name of the index."),
new FunctionParameterSequenceType("node", Type.NODE, Cardinality.ZERO_OR_ONE, "The node to look up.")
},
new FunctionReturnSequenceType(Type.LONG, Cardinality.ZERO_OR_ONE, "A number > 0 or the empty " +
"sequence if the $node argument was empty or the node could not be found in the index."));
public GetIndex(XQueryContext context) {
super(context, signature);
}
@Override
public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
if (args[1].isEmpty())
return Sequence.EMPTY_SEQUENCE;
String id = args[0].getStringValue();
NodeProxy node = (NodeProxy) args[1].itemAt(0);
SortIndexWorker index = (SortIndexWorker)
context.getBroker().getIndexController().getWorkerByIndexId(SortIndex.ID);
long pos = 0;
try {
pos = index.getIndex(id, node);
} catch (EXistException e) {
throw new XPathException(this, e.getMessage(), e);
} catch (LockException e) {
throw new XPathException(this, "Caught lock error while searching index. Giving up.", e);
}
return pos < 0 ? Sequence.EMPTY_SEQUENCE : new IntegerValue(pos, Type.LONG);
}
}