package net.sf.saxon.tree;
import net.sf.saxon.event.Builder;
import net.sf.saxon.event.LocationProvider;
import net.sf.saxon.event.PipelineConfiguration;
import net.sf.saxon.event.ReceiverOptions;
import net.sf.saxon.om.AttributeCollectionImpl;
import net.sf.saxon.om.DocumentInfo;
import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.Configuration;
import java.util.ArrayList;
/**
* The TreeBuilder class is responsible for taking a stream of Receiver events and constructing
* a Document tree using the linked tree implementation.
* @author Michael H. Kay
*/
public class TreeBuilder extends Builder
{
// private static AttributeCollectionImpl emptyAttributeCollection =
// new AttributeCollectionImpl((Configuration)null);
private ParentNodeImpl currentNode;
private boolean contentStarted = false; // provides a minimal check on correct sequence of calls
private NodeFactory nodeFactory;
private int[] size = new int[100]; // stack of number of children for each open node
private int depth = 0;
private ArrayList<NodeImpl[]> arrays = new ArrayList<NodeImpl[]>(20); // reusable arrays for creating nodes
private int elementNameCode;
private int elementTypeCode;
private int pendingLocationId;
private AttributeCollectionImpl attributes;
private int[] namespaces;
private int namespacesUsed;
private boolean allocateSequenceNumbers = true;
private int nextNodeNumber = 1;
private static final int[] EMPTY_ARRAY_OF_INT = new int[0];
/**
* create a Builder and initialise variables
*/
public TreeBuilder() {
nodeFactory = new DefaultNodeFactory();
// System.err.println("new TreeBuilder " + this);
}
/**
* Get the current root node. This will normally be a document node, but if the root of the tree
* is an element node, it can be an element.
* @return the root of the tree that is currently being built, or that has been most recently built
* using this builder
*/
public NodeInfo getCurrentRoot() {
NodeInfo physicalRoot = currentRoot;
if (physicalRoot instanceof DocumentImpl && ((DocumentImpl)physicalRoot).isImaginary()) {
return ((DocumentImpl)physicalRoot).getDocumentElement();
} else {
return physicalRoot;
}
}
public void reset() {
super.reset();
currentNode = null;
nodeFactory = null;
depth = 0;
allocateSequenceNumbers = true;
nextNodeNumber = 1;
}
/**
* Set whether the builder should allocate sequence numbers to elements as they are added to the
* tree. This is normally done, because it provides a quick way of comparing document order. But
* nodes added using XQuery update are not sequence-numbered.
* @param allocate true if sequence numbers are to be allocated
*/
public void setAllocateSequenceNumbers(boolean allocate) {
allocateSequenceNumbers = allocate;
}
/**
* Set the Node Factory to use. If none is specified, the Builder uses its own.
* @param factory the node factory to be used. This allows custom objects to be used to represent
* the elements in the tree.
*/
public void setNodeFactory(NodeFactory factory) {
nodeFactory = factory;
}
/**
* Open the stream of Receiver events
*/
public void open () throws XPathException {
started = true;
depth = 0;
size[depth] = 0;
super.open();
}
/**
* Start of a document node.
* This event is ignored: we simply add the contained elements to the current document
*/
public void startDocument(int properties) throws XPathException {
DocumentImpl doc = new DocumentImpl();
currentRoot = doc;
doc.setSystemId(getSystemId());
doc.setBaseURI(getBaseURI());
doc.setConfiguration(config);
currentNode = doc;
depth = 0;
size[depth] = 0;
doc.sequence = 0;
if (lineNumbering) {
doc.setLineNumbering();
}
contentStarted = true;
}
/**
* Notify the end of the document
*/
public void endDocument() throws XPathException {
// System.err.println("End document depth=" + depth);
currentNode.compact(size[depth]);
}
/**
* Close the stream of Receiver events
*/
public void close () throws XPathException {
// System.err.println("TreeBuilder: " + this + " End document");
if (currentNode==null) {
return; // can be called twice on an error path
}
currentNode.compact(size[depth]);
currentNode = null;
// we're not going to use this Builder again so give the garbage collector
// something to play with
arrays = null;
super.close();
nodeFactory = null;
}
/**
* Notify the start of an element
*/
public void startElement (int nameCode, int typeCode, int locationId, int properties) throws XPathException {
// System.err.println("TreeBuilder: " + this + " Start element depth=" + depth);
if (currentNode == null) {
startDocument(0);
((DocumentImpl)currentRoot).setImaginary(true);
}
elementNameCode = nameCode;
elementTypeCode = typeCode;
pendingLocationId = locationId;
namespacesUsed = 0;
attributes = null;
contentStarted = false;
}
public void namespace (int namespaceCode, int properties) {
if (contentStarted) {
throw new IllegalStateException("namespace() called after startContent()");
}
if (namespaces==null) {
namespaces = new int[5];
}
if (namespacesUsed == namespaces.length) {
int[] ns2 = new int[namespaces.length * 2];
System.arraycopy(namespaces, 0, ns2, 0, namespacesUsed);
namespaces = ns2;
}
namespaces[namespacesUsed++] = namespaceCode;
}
public void attribute(int nameCode, int typeCode, CharSequence value, int locationId, int properties)
throws XPathException {
properties &= ~ReceiverOptions.DISABLE_ESCAPING;
if (contentStarted) {
throw new IllegalStateException("attribute() called after startContent()");
}
if (attributes==null) {
attributes = new AttributeCollectionImpl(config);
}
attributes.addAttribute(nameCode, typeCode, value.toString(), locationId, properties);
}
public void startContent() throws XPathException {
// System.err.println("TreeBuilder: " + this + " startContent()");
if (contentStarted) {
throw new IllegalStateException("startContent() called more than once");
}
contentStarted = true;
if (attributes == null) {
attributes = AttributeCollectionImpl.EMPTY_ATTRIBUTE_COLLECTION;
} else {
attributes.compact();
}
int[] nslist = namespaces;
if (nslist == null || namespacesUsed == 0) {
nslist = EMPTY_ARRAY_OF_INT;
}
ElementImpl elem = nodeFactory.makeElementNode(
currentNode, elementNameCode, elementTypeCode,
attributes, nslist, namespacesUsed,
pipe,
pendingLocationId, (allocateSequenceNumbers ? nextNodeNumber++ : -1));
namespacesUsed = 0;
attributes = null;
// the initial array used for pointing to children will be discarded when the exact number
// of children in known. Therefore, it can be reused. So we allocate an initial array from
// a pool of reusable arrays. A nesting depth of >20 is so rare that we don't bother.
while (depth >= arrays.size()) {
arrays.add(new NodeImpl[20]);
}
elem.useChildrenArray(arrays.get(depth));
currentNode.addChild(elem, size[depth]++);
if (depth >= size.length - 1) {
int[] newsize = new int[size.length * 2];
System.arraycopy(size, 0, newsize, 0, size.length);
size = newsize;
}
size[++depth] = 0;
namespacesUsed = 0;
if (currentNode instanceof DocumentInfo) {
((DocumentImpl)currentNode).setDocumentElement(elem);
}
currentNode = elem;
}
/**
* Notify the end of an element
*/
public void endElement () throws XPathException {
// System.err.println("End element depth=" + depth);
if (!contentStarted) {
throw new IllegalStateException("missing call on startContent()");
}
currentNode.compact(size[depth]);
depth--;
currentNode = (ParentNodeImpl)currentNode.getParent();
}
/**
* Notify a text node. Adjacent text nodes must have already been merged
*/
public void characters (CharSequence chars, int locationId, int properties) throws XPathException {
// System.err.println("Characters: " + chars.toString() + " depth=" + depth);
if (!contentStarted) {
throw new IllegalStateException("missing call on startContent()");
}
if (chars.length()>0) {
// we rely on adjacent chunks of text having already been merged
//TextImpl n = new TextImpl(currentNode, bufferStart, length);
TextImpl n = new TextImpl(currentNode, chars.toString());
currentNode.addChild(n, size[depth]++);
}
}
/**
* Notify a processing instruction
*/
public void processingInstruction (String name, CharSequence remainder, int locationId, int properties) {
if (!contentStarted) {
throw new IllegalStateException("missing call on startContent()");
}
int nameCode = namePool.allocate("", "", name);
ProcInstImpl pi = new ProcInstImpl(nameCode, remainder.toString());
currentNode.addChild(pi, size[depth]++);
LocationProvider locator = pipe.getLocationProvider();
if (locator!=null) {
pi.setLocation(locator.getSystemId(locationId),
locator.getLineNumber(locationId));
}
}
/**
* Notify a comment
*/
public void comment (CharSequence chars, int locationId, int properties) throws XPathException {
if (!contentStarted) {
throw new IllegalStateException("missing call on startContent()");
}
CommentImpl comment = new CommentImpl(chars.toString());
currentNode.addChild(comment, size[depth]++);
}
/**
* graftElement() allows an element node to be transferred from one tree to another.
* This is a dangerous internal interface which is used only to contruct a stylesheet
* tree from a stylesheet using the "literal result element as stylesheet" syntax.
* The supplied element is grafted onto the current element as its only child.
* @param element the element to be grafted in as a new child.
*/
public void graftElement(ElementImpl element) throws XPathException {
currentNode.addChild(element, size[depth]++);
}
/**
* Set an unparsed entity URI for the document
*/
public void setUnparsedEntity(String name, String uri, String publicId) {
((DocumentImpl)currentRoot).setUnparsedEntity(name, uri, publicId);
}
//////////////////////////////////////////////////////////////////////////////
// Inner class DefaultNodeFactory. This creates the nodes in the tree.
// It can be overridden, e.g. when building the stylesheet tree
//////////////////////////////////////////////////////////////////////////////
private static class DefaultNodeFactory implements NodeFactory {
public ElementImpl makeElementNode(
NodeInfo parent,
int nameCode,
int typeCode,
AttributeCollectionImpl attlist,
int[] namespaces,
int namespacesUsed,
PipelineConfiguration pipe,
int locationId,
int sequenceNumber)
{
ElementImpl e = new ElementImpl();
if (namespacesUsed > 0) {
e.setNamespaceDeclarations(namespaces, namespacesUsed);
}
e.initialise(nameCode, typeCode, attlist, parent, sequenceNumber);
LocationProvider locator = pipe.getLocationProvider();
if (locator!=null) {
String baseURI = locator.getSystemId(locationId);
int lineNumber = locator.getLineNumber(locationId);
int columnNumber = locator.getColumnNumber(locationId);
e.setLocation(baseURI, lineNumber, columnNumber);
}
return e;
}
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//