/**
* Process one item in the population
*
* @param index the index of items
* @param item the item from the population to be processed
* @param c2 the XPath evaluation context
* @throws XPathException
*/
protected void processItem(HashMap<ComparisonKey, List<Item>> index, Item item, XPathContext c2)
throws XPathException {
SequenceIterator keys = keyExpression.iterate(c2);
boolean firstKey = true;
while (true) {
AtomicValue key = (AtomicValue) keys.next();
if (key == null) {
break;
}
ComparisonKey comparisonKey = comparer.getComparisonKey(key);
List<Item> g = index.get(comparisonKey);
if (g == null) {
List<Item> newGroup = new ArrayList<Item>(20);
newGroup.add(item);
groups.add(newGroup);
groupKeys.add(key);
index.put(comparisonKey, newGroup);
} else {
if (firstKey) {
g.add(item);
} else {
// if this is not the first key value for this item, we
// check whether the item is already in this group before
// adding it again. If it is in this group, then we know
// it will be at the end.
if (g.get(g.size() - 1) != item) {
g.add(item);
}
}
}
firstKey = false;
}
}
/** Evaluate the function in a boolean context */
public boolean effectiveBooleanValue(XPathContext c) throws XPathException {
SequenceIterator iter = argument[0].iterate(c);
boolean result;
if ((iter.getProperties() & SequenceIterator.LOOKAHEAD) != 0) {
result = !((LookaheadIterator) iter).hasNext();
} else {
result = iter.next() == null;
}
iter.close();
return result;
}
/**
* Show a query producing a sequence as its result and returning the sequence to the Java
* application in the form of an iterator. For each item in the result, its string value is
* output.
*/
public static void exampleToSequence() throws XPathException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery("for $i in 1 to 10 return ($i * $i)");
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
final SequenceIterator iter = exp.iterator(dynamicContext);
while (true) {
Item item = iter.next();
if (item == null) {
break;
}
System.out.println(item.getStringValue());
}
}
/**
* Build the grouping table forming groups of items with equal keys. This form of grouping allows
* a member of the population to be present in zero or more groups, one for each value of the
* grouping key.
*/
private void buildIndexedGroups() throws XPathException {
HashMap index = new HashMap(40);
XPathContext c2 = keyContext.newMinorContext();
c2.setCurrentIterator(population);
while (true) {
Item item = population.next();
if (item == null) {
break;
}
processItem(index, item, c2);
}
}
/**
* Returns <tt>true</tt> if the iteration has more elements. (In other words, returns
* <tt>true</tt> if <tt>next</tt> would return an element rather than throwing an exception.)
*
* @return <tt>true</tt> if the iterator has more elements.
* @throws SaxonApiUncheckedException if a dynamic error occurs during XPath evaluation that is
* detected at this point.
*/
public boolean hasNext() throws SaxonApiUncheckedException {
switch (state) {
case ON_ITEM:
return true;
case FINISHED:
return false;
case BEFORE_ITEM:
try {
next = XdmItem.wrapItem(base.next());
if (next == null) {
state = FINISHED;
return false;
} else {
state = ON_ITEM;
return true;
}
} catch (XPathException err) {
throw new SaxonApiUncheckedException(err);
}
default:
throw new IllegalStateException();
}
}
/**
* Convert an XPath value to an object in this object model. If the supplied value can be
* converted to an object in this model, of the specified class, then the conversion should be
* done and the resulting object returned. If the value cannot be converted, the method should
* return null. Note that the supplied class might be a List, in which case the method should
* inspect the contents of the Value to see whether they belong to this object model.
*
* @throws XPathException if the target class is explicitly associated with this object model, but
* the supplied value cannot be converted to the appropriate class
*/
public Object convertXPathValueToObject(Value value, Class target, XPathContext context)
throws XPathException {
// We accept the object if (a) the target class is Node, Node[], or NodeList,
// or (b) the supplied object is a node, or sequence of nodes, that wrap DOM nodes,
// provided that the target class is Object or a collection class
boolean requireDOM =
(Node.class.isAssignableFrom(target)
|| (target == NodeList.class)
|| (target.isArray() && Node.class.isAssignableFrom(target.getComponentType())));
// Note: we allow the declared type of the method argument to be a subclass of Node. If the
// actual
// node supplied is the wrong kind of node, this will result in a Java exception.
boolean allowDOM =
(target == Object.class
|| target.isAssignableFrom(ArrayList.class)
|| target.isAssignableFrom(HashSet.class)
|| (target.isArray() && target.getComponentType() == Object.class));
if (!(requireDOM || allowDOM)) {
return null;
}
List nodes = new ArrayList(20);
SequenceIterator iter = value.iterate(context);
while (true) {
Item item = iter.next();
if (item == null) {
break;
}
if (item instanceof VirtualNode) {
Object o = ((VirtualNode) item).getUnderlyingNode();
if (o instanceof Node) {
nodes.add(o);
} else {
if (requireDOM) {
DynamicError err =
new DynamicError(
"Extension function required class "
+ target.getName()
+ "; supplied value of class "
+ item.getClass().getName()
+ " could not be converted");
throw err;
}
;
}
} else if (requireDOM) {
if (item instanceof NodeInfo) {
nodes.add(NodeOverNodeInfo.wrap((NodeInfo) item));
} else {
DynamicError err =
new DynamicError(
"Extension function required class "
+ target.getName()
+ "; supplied value of class "
+ item.getClass().getName()
+ " could not be converted");
throw err;
}
} else {
return null; // DOM Nodes are not actually required; let someone else try the conversion
}
}
if (nodes.size() == 0 && !requireDOM) {
return null; // empty sequence supplied - try a different mapping
}
if (Node.class.isAssignableFrom(target)) {
if (nodes.size() != 1) {
DynamicError err =
new DynamicError(
"Extension function requires a single DOM Node"
+ "; supplied value contains "
+ nodes.size()
+ " nodes");
throw err;
}
return nodes.get(0);
// could fail if the node is of the wrong kind
} else if (target == NodeList.class) {
return new DOMNodeList(nodes);
} else if (target.isArray() && target.getComponentType() == Node.class) {
Node[] array = new Node[nodes.size()];
nodes.toArray(array);
return array;
} else if (target.isAssignableFrom(ArrayList.class)) {
return nodes;
} else if (target.isAssignableFrom(HashSet.class)) {
return new HashSet(nodes);
} else {
// after all this work, give up
return null;
}
}
/*@NotNull*/
public SequenceIterator getAnother() throws XPathException {
XPathContext c2 = keyContext.newMinorContext();
return new GroupByIterator(population.getAnother(), keyExpression, c2, collator);
}
private void runAdjacent() throws SaxonApiException {
TreeWriter treeWriter = null;
String last = null;
boolean open = false;
int count = 0;
while (source.moreDocuments()) {
count++;
source.read();
}
source.resetReader();
DocumentSequenceIterator xsi = new DocumentSequenceIterator(); // See below
xsi.setLast(count);
int pos = 0;
while (source.moreDocuments()) {
XdmNode node = source.read();
pos++;
Item item = null;
try {
XPathCompiler xcomp = runtime.getProcessor().newXPathCompiler();
xcomp.setBaseURI(step.getNode().getBaseURI());
for (String prefix : groupAdjacent.getNamespaceBindings().keySet()) {
xcomp.declareNamespace(prefix, groupAdjacent.getNamespaceBindings().get(prefix));
}
XPathExecutable xexec = xcomp.compile(groupAdjacent.getString());
// From Michael Kay: http://markmail.org/message/vkb2vaq2miylgndu
//
// Underneath the s9api XPathExecutable is a net.sf.saxon.sxpath.XPathExpression.
XPathExpression xexpr = xexec.getUnderlyingExpression();
// Call createDynamicContext() on this to get an XPathDynamicContext object;
XPathDynamicContext xdc = xexpr.createDynamicContext(node.getUnderlyingNode());
// call getXPathContextObject() on that to get the underlying XPathContext.
XPathContext xc = xdc.getXPathContextObject();
// Then call XPathContext.setCurrentIterator()
// to supply a SequenceIterator whose current() and position() methods return
// the context item and position respectively. If there's any risk that the
// expression will call the last() method, then it's simplest to make your
// iterator's getProperties() return LAST_POSITION_FINDER, and implement the
// LastPositionFinder interface, in which case last() will be implemented by
// calling the iterator's getLastPosition() method. (Otherwise last() is
// implemented by calling getAnother() to clone the iterator and calling next()
// on the clone until the end of the sequence is reached).
xsi.setPosition(pos);
xsi.setItem(node.getUnderlyingNode());
xc.setCurrentIterator(xsi);
// Then evaluate the expression by calling iterate() on the
// net.sf.saxon.sxpath.XPathExpression object.
SequenceIterator results = xexpr.iterate(xdc);
item = results.next();
if (item == null) {
throw new XProcException(
step.getNode(), "The group-adjacent expression returned nothing.");
}
if (results.next() != null) {
throw new XProcException(
step.getNode(), "Didn't expect group-adjacent to return a sequence!");
}
} catch (XPathException xe) {
throw new XProcException(xe);
}
//
// Good luck!
//
// FIXME: Compute effective boolean value in a more robust way
String cur = item.getStringValue();
if (last != null) {
if (last.equals(cur)) {
treeWriter.addSubtree(node);
} else {
if (open) {
open = false;
treeWriter.addEndElement();
treeWriter.endDocument();
result.write(treeWriter.getResult());
}
}
}
if (last == null || !last.equals(cur)) {
last = cur;
open = true;
treeWriter = new TreeWriter(runtime);
treeWriter.startDocument(step.getNode().getBaseURI());
treeWriter.addStartElement(wrapper);
treeWriter.startContent();
treeWriter.addSubtree(node);
}
}
if (open) {
open = false;
treeWriter.addEndElement();
treeWriter.endDocument();
result.write(treeWriter.getResult());
}
}
private static List<String> sequenceToList(Sequence seq) throws XPathException {
List<String> list = new ArrayList<String>();
for (SequenceIterator<?> i = seq.iterate(); i.next() != null; )
list.add(i.current().getStringValue());
return list;
}
private List<?> processRow()
throws ExpressionEvaluationException, BlockedException, TeiidComponentException,
TeiidProcessingException {
List<Object> tuple = new ArrayList<Object>(projectedColumns.size());
for (XMLColumn proColumn : projectedColumns) {
if (proColumn.isOrdinal()) {
if (rowCount > Integer.MAX_VALUE) {
throw new TeiidRuntimeException(
new TeiidProcessingException(
QueryPlugin.Event.TEIID31174, QueryPlugin.Util.gs(QueryPlugin.Event.TEIID31174)));
}
tuple.add((int) rowCount);
} else {
try {
XPathExpression path = proColumn.getPathExpression();
XPathDynamicContext dynamicContext = path.createDynamicContext(item);
SequenceIterator pathIter = path.iterate(dynamicContext);
Item colItem = pathIter.next();
if (colItem == null) {
if (proColumn.getDefaultExpression() != null) {
tuple.add(
getEvaluator(Collections.emptyMap())
.evaluate(proColumn.getDefaultExpression(), null));
} else {
tuple.add(null);
}
continue;
}
if (proColumn.getSymbol().getType() == DataTypeManager.DefaultDataClasses.XML) {
XMLType value =
table
.getXQueryExpression()
.createXMLType(
pathIter.getAnother(), this.getBufferManager(), false, getContext());
tuple.add(value);
continue;
}
Item next = pathIter.next();
if (next != null) {
if (proColumn.getSymbol().getType().isArray()) {
ArrayList<Object> vals = new ArrayList<Object>();
vals.add(
getValue(
proColumn.getSymbol().getType().getComponentType(),
colItem,
this.table.getXQueryExpression().getConfig(),
getContext()));
vals.add(
getValue(
proColumn.getSymbol().getType().getComponentType(),
next,
this.table.getXQueryExpression().getConfig(),
getContext()));
while ((next = pathIter.next()) != null) {
vals.add(
getValue(
proColumn.getSymbol().getType().getComponentType(),
next,
this.table.getXQueryExpression().getConfig(),
getContext()));
}
Object value =
new ArrayImpl(
vals.toArray(
(Object[])
Array.newInstance(
proColumn.getSymbol().getType().getComponentType(),
vals.size())));
tuple.add(value);
continue;
}
throw new TeiidProcessingException(
QueryPlugin.Event.TEIID30171,
QueryPlugin.Util.gs(QueryPlugin.Event.TEIID30171, proColumn.getName()));
}
Object value =
getValue(
proColumn.getSymbol().getType(),
colItem,
this.table.getXQueryExpression().getConfig(),
getContext());
tuple.add(value);
} catch (XPathException e) {
throw new TeiidProcessingException(
QueryPlugin.Event.TEIID30172,
e,
QueryPlugin.Util.gs(QueryPlugin.Event.TEIID30172, proColumn.getName()));
}
}
}
item = null;
return tuple;
}
