/**
* The constructor is protected, to ensure that instances can only be created using the
* compileQuery() methods of StaticQueryContext
*
* @param exp an expression to be wrapped as an XQueryExpression
* @param exec the executable
* @param mainModule the static context of the main module
* @param config the configuration
* @throws XPathException if an error occurs
*/
protected XQueryExpression(
Expression exp, Executable exec, QueryModule mainModule, Configuration config)
throws XPathException {
stackFrameMap = config.makeSlotManager();
executable = exec;
exp.setContainer(this);
try {
ExpressionVisitor visitor = ExpressionVisitor.make(mainModule);
visitor.setExecutable(exec);
exp = visitor.simplify(exp);
exp.checkForUpdatingSubexpressions();
exp = visitor.typeCheck(exp, mainModule.getUserQueryContext().getRequiredContextItemType());
// ExpressionPresenter presenter = new ExpressionPresenter(config,
// ExpressionPresenter.defaultDestination(config, new
// FileOutputStream("c:/projects/montreal/before50.xml")));
// exp.explain(presenter);
// presenter.close();
exp = exp.optimize(visitor, Type.ITEM_TYPE);
} catch (XPathException err) {
// err.printStackTrace();
mainModule.reportFatalError(err);
throw err;
}
ExpressionTool.allocateSlots(exp, 0, stackFrameMap);
expression = exp;
executable.setConfiguration(config);
executable.setDefaultCollationName(mainModule.getDefaultCollationName());
executable.setCollationTable(mainModule.getUserQueryContext().getAllCollations());
staticContext = mainModule;
isUpdating = exp.isUpdatingExpression();
}
/**
* Get the path map for the query expression
*
* @return the path map (which is constructed if this has not already been done)
*/
public PathMap getPathMap() {
if (pathMap == null) {
pathMap = new PathMap(expression);
}
HashMap map = executable.getCompiledGlobalVariables();
if (map != null) {
Iterator iter = map.values().iterator();
while (iter.hasNext()) {
GlobalVariable var = (GlobalVariable) iter.next();
Expression select = var.getSelectExpression();
select.addToPathMap(pathMap, null);
}
}
return pathMap;
}
/**
* Run an updating query, writing back eligible updated node to persistent storage.
*
* <p>A node is eligible to be written back to disk if it is present in the document pool, which
* generally means that it was originally read using the doc() or collection() function.
*
* <p>On completion of this method it is generally unsafe to rely on the contents or relationships
* of NodeInfo objects that were obtained before the updating query was run. Such objects may or
* may not reflect the results of the update operations. This is especially true in the case of
* nodes that are part of a subtree that has been deleted (detached from its parent). Instead, the
* new updated tree should be accessed by navigation from the root nodes returned by this method.
*
* <p>If one or more eligible updated nodes cannot be written back to disk, perhaps because the
* URI identifies a non-updatable location, then an exception is thrown. In this case it is
* undefined
*
* @param dynamicEnv the dynamic context for query execution
* @throws XPathException if evaluation of the update query fails, or it this is not an updating
* query
*/
public void runUpdate(DynamicQueryContext dynamicEnv, UpdateAgent agent) throws XPathException {
if (!isUpdating) {
throw new XPathException("Calling runUpdate() on a non-updating query");
}
Configuration config = executable.getConfiguration();
Controller controller = newController();
initializeController(dynamicEnv, controller);
XPathContextMajor context = initialContext(dynamicEnv, controller);
try {
PendingUpdateList pul = config.newPendingUpdateList();
context.openStackFrame(stackFrameMap);
expression.evaluatePendingUpdates(context, pul);
pul.apply(context, staticContext.getRevalidationMode());
for (Iterator iter = pul.getAffectedTrees().iterator(); iter.hasNext(); ) {
NodeInfo node = (NodeInfo) iter.next();
agent.update(node, controller);
}
} catch (XPathException e) {
if (!e.hasBeenReported()) {
try {
controller.getErrorListener().fatalError(e);
} catch (TransformerException e2) {
// ignore secondary error
}
}
throw e;
}
}
/**
* Ask whether this query uses the context item
*
* @return true if the context item is referenced either in the query body or in the initializer
* of any global variable
*/
public boolean usesContextItem() {
if ((expression.getDependencies() & StaticProperty.DEPENDS_ON_FOCUS) != 0) {
return true;
}
HashMap map = executable.getCompiledGlobalVariables();
if (map != null) {
Iterator iter = map.values().iterator();
while (iter.hasNext()) {
GlobalVariable var = (GlobalVariable) iter.next();
Expression select = var.getSelectExpression();
if (select != null && (select.getDependencies() & StaticProperty.DEPENDS_ON_FOCUS) != 0) {
return true;
}
}
}
return false;
}
/**
* Run the query, sending the results directly to a JAXP Result object. This way of executing the
* query is most efficient in the case of queries that produce a single document (or parentless
* element) as their output, because it avoids constructing the result tree in memory: instead, it
* is piped straight to the serializer.
*
* @param env the dynamic query context
* @param result the destination for the results of the query. The query is effectively wrapped in
* a document{} constructor, so that the items in the result are concatenated to form a single
* document; this is then written to the requested Result destination, which may be (for
* example) a DOMResult, a SAXResult, or a StreamResult
* @param outputProperties Supplies serialization properties, in JAXP format, if the result is to
* be serialized. This parameter can be defaulted to null.
* @throws XPathException if the query fails.
*/
public void run(DynamicQueryContext env, Result result, Properties outputProperties)
throws XPathException {
if (isUpdating) {
throw new XPathException("Cannot call run() on an updating query");
}
Controller controller = newController();
initializeController(env, controller);
if (allowDocumentProjection) {
controller.setUseDocumentProjection(getPathMap());
}
Properties actualProperties = validateOutputProperties(controller, outputProperties);
controller.defineGlobalParameters();
XPathContextMajor context = initialContext(env, controller);
// In tracing/debugging mode, evaluate all the global variables first
TraceListener tracer = controller.getTraceListener();
if (tracer != null) {
controller.preEvaluateGlobals(context);
tracer.open();
}
context.openStackFrame(stackFrameMap);
boolean mustClose =
(result instanceof StreamResult && ((StreamResult) result).getOutputStream() == null);
context.changeOutputDestination(
actualProperties, result, true, Configuration.XQUERY, Validation.PRESERVE, null);
context.getReceiver().open();
// Run the query
try {
expression.process(context);
} catch (XPathException err) {
controller.reportFatalError(err);
throw err;
}
if (tracer != null) {
tracer.close();
}
context.getReceiver().close();
if (mustClose) {
OutputStream os = ((StreamResult) result).getOutputStream();
if (os != null) {
try {
os.close();
} catch (java.io.IOException err) {
throw new XPathException(err);
}
}
}
}
/**
* Diagnostic method: display a representation of the compiled query on the selected output
* stream.
*
* @param out an ExpressionPresenter to which the XML representation of the compiled query will be
* sent
*/
public void explain(ExpressionPresenter out) {
out.startElement("query");
staticContext.getExecutable().getKeyManager().explainKeys(out);
staticContext.getExecutable().explainGlobalVariables(out);
staticContext.explainGlobalFunctions(out);
out.startElement("body");
expression.explain(out);
out.endElement();
out.endElement();
out.close();
}
/**
* Get an iterator over the results of the expression. This returns results without any conversion
* of the returned items to "native" Java classes. The iterator will deliver a sequence of Item
* objects, each item being either a NodeInfo (representing a node) or an AtomicValue
* (representing an atomic value).
*
* <p>
*
* <p>To get the results of the query in the form of an XML document in which each item is wrapped
* by an element indicating its type, use:
*
* <p>
*
* <p><code>QueryResult.wrap(iterator(env))</code>
*
* <p>
*
* <p>To serialize the results to a file, use the QueryResult.serialize() method.
*
* @param env Provides the dynamic query evaluation context
* @return an iterator over the results of the query. The class SequenceIterator is modeled on the
* standard Java Iterator class, but has extra functionality and can throw exceptions when
* errors occur.
* @throws XPathException if a dynamic error occurs in evaluating the query. Some dynamic errors
* will not be reported by this method, but will only be reported when the individual items of
* the result are accessed using the returned iterator.
*/
public SequenceIterator iterator(DynamicQueryContext env) throws XPathException {
if (isUpdating) {
throw new XPathException("Cannot call iterator() on an updating query");
}
Controller controller = newController();
initializeController(env, controller);
try {
Item contextItem = env.getContextItem();
// Bindery bindery = controller.getBindery();
// bindery.openStackFrame();
controller.defineGlobalParameters();
XPathContextMajor context = controller.newXPathContext();
if (contextItem != null) {
if (!staticContext
.getUserQueryContext()
.getRequiredContextItemType()
.matchesItem(contextItem, false, env.getConfiguration())) {
throw new XPathException(
"The supplied context item does not match the required context item type");
}
UnfailingIterator single = SingletonIterator.makeIterator(contextItem);
single.next();
context.setCurrentIterator(single);
controller.setInitialContextItem(contextItem);
}
// In tracing/debugging mode, evaluate all the global variables first
if (controller.getTraceListener() != null) {
controller.preEvaluateGlobals(context);
}
context.openStackFrame(stackFrameMap);
SequenceIterator iterator = expression.iterate(context);
return new ErrorReportingIterator(iterator, controller.getErrorListener());
} catch (XPathException err) {
TransformerException terr = err;
while (terr.getException() instanceof TransformerException) {
terr = (TransformerException) terr.getException();
}
XPathException de = XPathException.makeXPathException(terr);
controller.reportFatalError(de);
throw de;
}
}
/**
* Run the query returning the results as an EventIterator
*
* @param controller The Controller used to run the query
* @param dynamicEnv the XQuery dynamic context for evaluating the query
* @return an EventIterator representing the results of the query as a sequence of events
*/
public EventIterator iterateEvents(Controller controller, DynamicQueryContext dynamicEnv)
throws XPathException {
if (isUpdating) {
throw new XPathException("Cannot call iterateEvents() on an updating query");
}
initializeController(dynamicEnv, controller);
XPathContextMajor context = initialContext(dynamicEnv, controller);
// In tracing/debugging mode, evaluate all the global variables first
if (controller.getTraceListener() != null) {
controller.preEvaluateGlobals(context);
}
context.openStackFrame(stackFrameMap);
final Configuration config = executable.getConfiguration();
EventIterator ei = expression.iterateEvents(context);
// ei = new TracingEventIterator(EventStackIterator.flatten(ei));
return new ComplexContentProcessor(config, ei);
}