net.sf.saxon.option.xom.XOMNodeWrapper Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of Saxon-HE Show documentation
Show all versions of Saxon-HE Show documentation
The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2022 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.option.xom;
import net.sf.saxon.Configuration;
import net.sf.saxon.om.*;
import net.sf.saxon.pattern.AnyNodeTest;
import net.sf.saxon.pattern.NodeTest;
import net.sf.saxon.str.StringView;
import net.sf.saxon.str.UnicodeString;
import net.sf.saxon.tree.iter.AxisIterator;
import net.sf.saxon.tree.iter.EmptyIterator;
import net.sf.saxon.tree.util.Navigator;
import net.sf.saxon.tree.util.SteppingNavigator;
import net.sf.saxon.tree.util.SteppingNode;
import net.sf.saxon.tree.wrapper.AbstractNodeWrapper;
import net.sf.saxon.tree.wrapper.SiblingCountingNode;
import net.sf.saxon.type.Type;
import net.sf.saxon.value.StringValue;
import nu.xom.*;
import java.util.ArrayList;
import java.util.List;
/**
* A node in the XML parse tree representing an XML element, character content,
* or attribute.
* This is the implementation of the NodeInfo interface used as a wrapper for
* XOM nodes.
*
* @author Michael H. Kay
* @author Wolfgang Hoschek (ported net.sf.saxon.jdom to XOM)
*/
public class XOMNodeWrapper extends AbstractNodeWrapper implements SiblingCountingNode, SteppingNode {
protected Node node;
protected short nodeKind;
private XOMNodeWrapper parent; // null means unknown
protected XOMDocumentWrapper docWrapper;
//represents the index position in it's parent child nodes
protected int index; // -1 means unknown
private NamespaceMap inScopeNamespaces = null;
/**
* This constructor is protected: nodes should be created using the wrap
* factory method on the XOMDocumentWrapper class
*
* @param node The XOM node to be wrapped
* @param parent The XOMNodeWrapper that wraps the parent of this node
* @param index Position of this node among its siblings
*/
XOMNodeWrapper(Node node, XOMNodeWrapper parent, int index) {
short kind;
if (node instanceof Element) {
kind = Type.ELEMENT;
} else if (node instanceof Text) {
kind = Type.TEXT;
} else if (node instanceof Attribute) {
kind = Type.ATTRIBUTE;
} else if (node instanceof Comment) {
kind = Type.COMMENT;
} else if (node instanceof ProcessingInstruction) {
kind = Type.PROCESSING_INSTRUCTION;
} else if (node instanceof Document) {
kind = Type.DOCUMENT;
} else {
throwIllegalNode(node); // moved out of fast path to enable better inlining
return; // keep compiler happy
}
nodeKind = kind;
this.node = node;
this.parent = parent;
this.index = index;
}
/**
* Factory method to wrap a XOM node with a wrapper that implements the
* Saxon NodeInfo interface.
*
* @param node The XOM node
* @param docWrapper The wrapper for the Document containing this node
* @return The new wrapper for the supplied node
*/
protected final XOMNodeWrapper makeWrapper(Node node, XOMDocumentWrapper docWrapper) {
return makeWrapper(node, docWrapper, null, -1);
}
/**
* Factory method to wrap a XOM node with a wrapper that implements the
* Saxon NodeInfo interface.
*
* @param node The XOM node
* @param docWrapper The wrapper for the Document containing this node
* @param parent The wrapper for the parent of the XOM node
* @param index The position of this node relative to its siblings
* @return The new wrapper for the supplied node
*/
protected final XOMNodeWrapper makeWrapper(Node node, XOMDocumentWrapper docWrapper,
XOMNodeWrapper parent, int index) {
if (node == docWrapper.node) {
return docWrapper;
}
XOMNodeWrapper wrapper = new XOMNodeWrapper(node, parent, index);
wrapper.docWrapper = docWrapper;
wrapper.treeInfo = docWrapper;
return wrapper;
}
private static void throwIllegalNode(/*@Nullable*/ Node node) {
String str = node == null ?
"NULL" :
node.getClass() + " instance " + node;
throw new IllegalArgumentException("Bad node type in XOM! " + str);
}
/**
* Get the configuration
*/
@Override
public Configuration getConfiguration() {
return docWrapper.getConfiguration();
}
/**
* Get the underlying XOM node, to implement the VirtualNode interface
*/
@Override
public Node getUnderlyingNode() {
return node;
}
/**
* Get the name pool for this node
*
* @return the NamePool
*/
@Override
public NamePool getNamePool() {
return docWrapper.getNamePool();
}
/**
* Return the type of node.
*
* @return one of the values Node.ELEMENT, Node.TEXT, Node.ATTRIBUTE, etc.
*/
@Override
public int getNodeKind() {
return nodeKind;
}
/**
* Get the typed value.
*
* @return the typed value. If requireSingleton is set to true, the result
* will always be an AtomicValue. In other cases it may be a Value
* representing a sequence whose items are atomic values.
* @since 8.5
*/
@Override
public AtomicSequence atomize() {
switch (getNodeKind()) {
case Type.COMMENT:
case Type.PROCESSING_INSTRUCTION:
return new StringValue(getUnicodeStringValue());
default:
return StringValue.makeUntypedAtomic(getUnicodeStringValue());
}
}
/**
* Determine whether this is the same node as another node.
* Note: a.isSameNode(b) if and only if generateId(a)==generateId(b)
*
* @return true if this Node object and the supplied Node object represent
* the same node in the tree.
*/
public boolean equals(Object other) {
// In XOM equality means identity
return other instanceof XOMNodeWrapper && node == ((XOMNodeWrapper) other).node;
}
/**
* The hashCode() method obeys the contract for hashCode(): that is, if two objects are equal
* (represent the same node) then they must have the same hashCode()
*
* @since 8.7 Previously, the effect of the equals() and hashCode() methods was not defined. Callers
* should therefore be aware that third party implementations of the NodeInfo interface may
* not implement the correct semantics.
*/
public int hashCode() {
return node.hashCode();
}
/**
* Get the System ID for the node.
*
* @return the System Identifier of the entity in the source document
* containing the node, or null if not known. Note this is not the
* same as the base URI: the base URI can be modified by xml:base,
* but the system ID cannot.
*/
@Override
public String getSystemId() {
return docWrapper.getBaseURI();
}
/**
* Get the Base URI for the node, that is, the URI used for resolving a
* relative URI contained in the node.
*/
@Override
public String getBaseURI() {
return node.getBaseURI();
}
/**
* Determine the relative position of this node and another node, in
* document order. The other node will always be in the same document.
*
* @param other The other node, whose position is to be compared with this
* node
* @return -1 if this node precedes the other node, +1 if it follows the
* other node, or 0 if they are the same node. (In this case,
* isSameNode() will always return true, and the two nodes will
* produce the same result for generateId())
*/
@Override
public int compareOrder(NodeInfo other) {
if (other instanceof XOMNodeWrapper) {
return compareOrderFast(node, ((XOMNodeWrapper) other).node);
} else {
// it must be a namespace node
return -other.compareOrder(this);
}
}
private static int compareOrderFast(Node first, Node second) {
/*
* Unfortunately we do not have a sequence number for each node at hand;
* this would allow to turn the comparison into a simple sequence number
* subtraction. Walking the entire tree and batch-generating sequence
* numbers on the fly is no good option either. However, this rewritten
* implementation turns out to be more than fast enough.
*/
// assert first != null && second != null
// assert first and second MUST NOT be namespace nodes
if (first == second) {
return 0;
}
ParentNode firstParent = first.getParent();
ParentNode secondParent = second.getParent();
if (firstParent == null) {
if (secondParent != null) {
return -1; // first node is the root
}
// both nodes are parentless, use arbitrary but fixed order:
return first.hashCode() - second.hashCode();
}
if (secondParent == null) {
return +1; // second node is the root
}
// do they have the same parent (common case)?
if (firstParent == secondParent) {
int i1 = firstParent.indexOf(first);
int i2 = firstParent.indexOf(second);
// note that attributes and namespaces are not children
// of their own parent (i = -1).
// attribute (if any) comes before child
if (i1 != -1) {
return (i2 != -1) ? i1 - i2 : +1;
}
if (i2 != -1) {
return -1;
}
// assert: i1 == -1 && i2 == -1
// i.e. both nodes are attributes
Element elem = (Element) firstParent;
for (int i = elem.getAttributeCount(); --i >= 0; ) {
Attribute attr = elem.getAttribute(i);
if (attr == second) {
return -1;
}
if (attr == first) {
return +1;
}
}
throw new IllegalStateException("should be unreachable");
}
// find the depths of both nodes in the tree
int depth1 = 0;
int depth2 = 0;
Node p1 = first;
Node p2 = second;
while (p1 != null) {
depth1++;
p1 = p1.getParent();
if (p1 == second) {
return +1;
}
}
while (p2 != null) {
depth2++;
p2 = p2.getParent();
if (p2 == first) {
return -1;
}
}
// move up one branch of the tree so we have two nodes on the same level
p1 = first;
while (depth1 > depth2) {
p1 = p1.getParent();
depth1--;
}
p2 = second;
while (depth2 > depth1) {
p2 = p2.getParent();
depth2--;
}
// now move up both branches in sync until we find a common parent
while (true) {
firstParent = p1.getParent();
secondParent = p2.getParent();
if (firstParent == null || secondParent == null) {
// both nodes are documentless, use arbitrary but fixed order
// based on their root elements
return p1.hashCode() - p2.hashCode();
// throw new NullPointerException("XOM tree compare - internal error");
}
if (firstParent == secondParent) {
return firstParent.indexOf(p1) - firstParent.indexOf(p2);
}
p1 = firstParent;
p2 = secondParent;
}
}
/**
* Return the string value of the node. The interpretation of this depends
* on the type of node. For an element it is the accumulated character
* content of the element, including descendant elements.
*
* @return the string value of the node
*/
@Override
public UnicodeString getUnicodeStringValue() {
return StringView.tidy(node.getValue());
}
/**
* Get the local part of the name of this node. This is the name after the
* ":" if any.
*
* @return the local part of the name. For an unnamed node, returns "".
*/
@Override
public String getLocalPart() {
switch (nodeKind) {
case Type.ELEMENT:
return ((Element) node).getLocalName();
case Type.ATTRIBUTE:
return ((Attribute) node).getLocalName();
case Type.PROCESSING_INSTRUCTION:
return ((ProcessingInstruction) node).getTarget();
default:
return "";
}
}
/**
* Get the prefix of the name of the node. This is defined only for elements and attributes.
* If the node has no prefix, or for other kinds of node, return a zero-length string.
*
* @return The prefix of the name of the node.
*/
@Override
public String getPrefix() {
switch (nodeKind) {
case Type.ELEMENT:
return ((Element) node).getNamespacePrefix();
case Type.ATTRIBUTE:
return ((Attribute) node).getNamespacePrefix();
default:
return "";
}
}
/**
* Get the URI part of the name of this node. This is the URI corresponding
* to the prefix, or the URI of the default namespace if appropriate.
*
* @return The URI of the namespace of this node. For an unnamed node, or
* for a node with an empty prefix, return an empty string.
*/
@Override
public String getURI() {
switch (nodeKind) {
case Type.ELEMENT:
return ((Element) node).getNamespaceURI();
case Type.ATTRIBUTE:
return ((Attribute) node).getNamespaceURI();
default:
return "";
}
}
/**
* Get the display name of this node. For elements and attributes this is
* [prefix:]localname. For unnamed nodes, it is an empty string.
*
* @return The display name of this node. For a node with no name, return an
* empty string.
*/
@Override
public String getDisplayName() {
switch (nodeKind) {
case Type.ELEMENT:
return ((Element) node).getQualifiedName();
case Type.ATTRIBUTE:
return ((Attribute) node).getQualifiedName();
case Type.PROCESSING_INSTRUCTION:
return ((ProcessingInstruction) node).getTarget();
default:
return "";
}
}
/**
* Get the NodeInfo object representing the parent of this node
*/
@Override
public XOMNodeWrapper getParent() {
if (parent == null) {
ParentNode p = node.getParent();
if (p != null) {
parent = makeWrapper(p, docWrapper);
}
}
return parent;
}
@Override
public XOMNodeWrapper getNextSibling() {
ParentNode parenti = node.getParent();
if (parenti == null) {
return null;
}
int count = parenti.getChildCount();
if (index != -1) {
if ((index + 1) < count) {
return makeWrapper(parenti.getChild(index + 1), docWrapper, parent, index + 1);
} else {
return null;
}
}
index = parenti.indexOf(node);
if (index + 1 < count) {
return makeWrapper(parenti.getChild(index + 1), docWrapper, parent, index + 1);
}
return null;
}
@Override
public XOMNodeWrapper getPreviousSibling() {
ParentNode parenti = node.getParent();
if (parenti == null) {
return null;
}
if (index != -1) {
if ((index - 1) > 0) {
return makeWrapper(parenti.getChild(index - 1), docWrapper, parent, index - 1);
} else {
return null;
}
}
index = parenti.indexOf(node);
if (index - 1 > 0) {
return makeWrapper(parenti.getChild(index - 1), docWrapper, parent, index - 1);
}
return null;
}
@Override
public XOMNodeWrapper getFirstChild() {
if (node.getChildCount() > 0) {
for (int i = 0; i < node.getChildCount(); i++) {
Node n = node.getChild(i);
if (!(n instanceof DocType)) {
return makeWrapper(n, docWrapper, this, 0);
}
}
}
return null;
}
@Override
public SteppingNode getSuccessorElement(SteppingNode anchor, String uri, String local) {
Node stop = anchor == null ? null : ((XOMNodeWrapper)anchor).node;
Node next = node;
do {
next = getSuccessorNode(next, stop);
} while (next != null &&
!(next instanceof Element &&
(uri == null || uri.equals(((Element) next).getNamespaceURI())) &&
(local == null || local.equals(((Element) next).getLocalName()))));
if (next == null) {
return null;
} else {
return makeWrapper(next, docWrapper);
}
}
/**
* Get the following node in an iteration of descendants
*
* @param start the start node
* @param anchor the node marking the root of the subtree within which navigation takes place (may be null)
* @return the next node in document order after the start node, excluding attributes and namespaces
*/
private static Node getSuccessorNode(Node start, Node anchor) {
if (start.getChildCount() > 0) {
return start.getChild(0);
}
if (start == anchor) {
return null;
}
Node p = start;
while (true) {
ParentNode q = p.getParent();
if (q == null) {
return null;
}
int i = q.indexOf(p) + 1;
if (i < q.getChildCount()) {
return q.getChild(i);
}
if (q == anchor) {
return null;
}
p = q;
}
}
/**
* Get the index position of this node among its siblings (starting from 0)
*/
@Override
public int getSiblingPosition() {
// This method is used only to support generate-id()
if (index != -1) {
return index;
}
switch (nodeKind) {
case Type.ATTRIBUTE: {
Attribute att = (Attribute) node;
Element p = (Element) att.getParent();
if (p == null) {
return 0;
}
for (int i = p.getAttributeCount(); --i >= 0; ) {
if (p.getAttribute(i) == att) {
index = i;
return i;
}
}
throw new IllegalStateException("XOM node not linked to parent node");
}
default: {
ParentNode p = node.getParent();
int i = p == null ? 0 : p.indexOf(node);
if (i == -1) {
throw new IllegalStateException("XOM node not linked to parent node");
}
index = i;
return index;
}
}
}
@Override
protected AxisIterator iterateAttributes(NodeTest nodeTest) {
return new Navigator.AxisFilter(
new AttributeAxisIterator(this, nodeTest),
nodeTest);
}
@Override
protected AxisIterator iterateChildren(NodeTest nodeTest) {
if (hasChildNodes()) {
return new Navigator.AxisFilter(
new ChildAxisIterator(this, true, true, nodeTest),
nodeTest);
} else {
return EmptyIterator.ofNodes();
}
}
@Override
protected AxisIterator iterateSiblings(NodeTest nodeTest, boolean forwards) {
return new Navigator.AxisFilter(
new ChildAxisIterator(this, false, forwards, nodeTest),
nodeTest);
}
@Override
protected AxisIterator iterateDescendants(NodeTest nodeTest, boolean includeSelf) {
if (includeSelf) {
return new SteppingNavigator.DescendantAxisIterator(
this, true, nodeTest);
} else {
if (hasChildNodes()) {
return new SteppingNavigator.DescendantAxisIterator(
this, false, nodeTest);
} else {
return EmptyIterator.ofNodes();
}
}
}
/**
* Get the string value of a given attribute of this node
*
* @param uri the namespace URI of the attribute name. Supply the empty string for an attribute
* that is in no namespace
* @param local the local part of the attribute name.
* @return the attribute value if it exists, or null if it does not exist. Always returns null
* if this node is not an element.
* @since 9.4
*/
@Override
public String getAttributeValue(/*@NotNull*/ String uri, /*@NotNull*/ String local) {
if (nodeKind == Type.ELEMENT) {
Attribute att = ((Element) node).getAttribute(local, uri);
if (att != null) {
return att.getValue();
}
}
return null;
}
/**
* Get the root node of the tree containing this node
*
* @return the NodeInfo representing the top-level ancestor of this node.
* This will not necessarily be a document node
*/
@Override
public NodeInfo getRoot() {
return docWrapper;
}
/**
* Determine whether the node has any children.
* Note: the result is equivalent to
* getEnumeration(Axis.CHILD, AnyNodeTest.getInstance()).hasNext()
*/
@Override
public boolean hasChildNodes() {
return node.getChildCount() > 0;
}
/**
* Get a character string that uniquely identifies this node. Note:
* a.isSameNode(b) if and only if generateId(a)==generateId(b)
*
* @param buffer a buffer to contain a string that uniquely identifies this node, across all documents
*/
@Override
public void generateId(StringBuilder buffer) {
Navigator.appendSequentialKey(this, buffer, true);
//buffer.append(Navigator.getSequentialKey(this));
}
/**
* Get all namespace undeclarations and undeclarations defined on this element.
*
* @param buffer If this is non-null, and the result array fits in this buffer, then the result
* may overwrite the contents of this array, to avoid the cost of allocating a new array on the heap.
* @return An array of integers representing the namespace declarations and undeclarations present on
* this element. For a node other than an element, return null. Otherwise, the returned array is a
* sequence of namespace codes, whose meaning may be interpreted by reference to the name pool. The
* top half word of each namespace code represents the prefix, the bottom half represents the URI.
* If the bottom half is zero, then this is a namespace undeclaration rather than a declaration.
* The XML namespace is never included in the list. If the supplied array is larger than required,
* then the first unused entry will be set to -1.
* For a node other than an element, the method returns null.
*/
@Override
public NamespaceBinding[] getDeclaredNamespaces(NamespaceBinding[] buffer) {
if (node instanceof Element) {
Element elem = (Element) node;
int size = elem.getNamespaceDeclarationCount();
if (size == 0) {
return NamespaceBinding.EMPTY_ARRAY;
}
List list = new ArrayList<>(size);
for (int i = 0, j = 0; i < size; i++) {
String prefix = elem.getNamespacePrefix(i);
String uri = elem.getNamespaceURI(prefix);
if (prefix.isEmpty() && uri.isEmpty()) {
// include the default namespace undeclaration xmlns="" only if needed
ParentNode parent = node.getParent();
if (parent instanceof Element && !((Element)parent).getNamespaceURI("").isEmpty()) {
list.add(new NamespaceBinding(prefix, uri));
}
} else {
list.add(new NamespaceBinding(prefix, uri));
}
}
return list.toArray(NamespaceBinding.EMPTY_ARRAY);
} else {
return null;
}
}
/**
* Get all the namespace bindings that are in-scope for this element.
* For an element return all the prefix-to-uri bindings that are in scope. This may include
* a binding to the default namespace (represented by a prefix of ""). It will never include
* "undeclarations" - that is, the namespace URI will never be empty; the effect of an undeclaration
* is to remove a binding from the in-scope namespaces, not to add anything.
* For a node other than an element, returns null.
*
* @return the in-scope namespaces for an element, or null for any other kind of node.
*/
@Override
public NamespaceMap getAllNamespaces() {
if (getNodeKind() == Type.ELEMENT) {
if (inScopeNamespaces != null) {
return inScopeNamespaces;
} else {
NodeInfo parent = getParent();
NamespaceMap nsMap = parent != null && parent.getNodeKind() == Type.ELEMENT
? parent.getAllNamespaces()
: NamespaceMap.emptyMap();
Element elem = (Element) node;
int size = elem.getNamespaceDeclarationCount();
for (int i = 0; i < size; i++) {
String prefix = elem.getNamespacePrefix(i);
String uri = elem.getNamespaceURI(prefix);
nsMap = nsMap.bind(prefix, uri);
}
return inScopeNamespaces = nsMap;
}
} else {
// not an element node
return null;
}
}
/**
* Determine whether this node has the is-id property
*
* @return true if the node is an ID
*/
@Override
public boolean isId() {
return getNodeKind() == Type.ATTRIBUTE && ((Attribute) node).getType() == Attribute.Type.ID;
}
/**
* Determine whether this node has the is-idref property
*
* @return true if the node is an IDREF or IDREFS element or attribute
*/
@Override
public boolean isIdref() {
return getNodeKind() == Type.ATTRIBUTE && (
((Attribute) node).getType() == Attribute.Type.IDREF ||
((Attribute) node).getType() == Attribute.Type.IDREFS);
}
///////////////////////////////////////////////////////////////////////////////
// Axis enumeration classes
///////////////////////////////////////////////////////////////////////////////
/**
* Handles the attribute axis in a rather direct manner.
*/
private final class AttributeAxisIterator implements AxisIterator {
private final XOMNodeWrapper start;
private int cursor;
private final NodeTest nodeTest;
AttributeAxisIterator(XOMNodeWrapper start, NodeTest test) {
// use lazy instead of eager materialization (performance)
this.start = start;
if (test == AnyNodeTest.getInstance()) {
test = null;
}
nodeTest = test;
cursor = 0;
}
@Override
public NodeInfo next() {
NodeInfo curr;
do { // until we find a match
curr = advance();
} while (curr != null && nodeTest != null && !nodeTest.test(curr));
return curr;
}
private NodeInfo advance() {
Element elem = (Element) start.node;
if (cursor == elem.getAttributeCount()) {
return null;
}
NodeInfo curr = makeWrapper(elem.getAttribute(cursor), docWrapper, start, cursor);
cursor++;
return curr;
}
} // end of class AttributeAxisIterator
/**
* The class ChildAxisIterator handles not only the child axis, but also the
* following-sibling and preceding-sibling axes. It can also iterate the
* children of the start node in reverse order, something that is needed to
* support the preceding and preceding-or-ancestor axes (the latter being
* used by xsl:number)
*/
private final class ChildAxisIterator implements AxisIterator {
private final XOMNodeWrapper commonParent;
private int ix;
private final boolean forwards; // iterate in document order (not reverse order)
private final ParentNode par;
private int cursor;
private final NodeTest nodeTest;
private ChildAxisIterator(XOMNodeWrapper start, boolean downwards, boolean forwards, NodeTest test) {
this.forwards = forwards;
if (test == AnyNodeTest.getInstance()) {
test = null;
}
nodeTest = test;
commonParent = downwards ? start : start.getParent();
par = (ParentNode) commonParent.node;
if (downwards) {
ix = forwards ? 0 : par.getChildCount();
} else {
// find the start node among the list of siblings
ix = par.indexOf(start.node);
if (forwards) {
ix++;
}
}
cursor = ix;
if (!downwards && !forwards) {
ix--;
}
}
@Override
public NodeInfo next() {
NodeInfo curr;
do { // until we find a match
curr = advance();
} while (curr != null && nodeTest != null && !nodeTest.test(curr));
return curr;
}
private NodeInfo advance() {
Node nextChild;
do {
if (forwards) {
if (cursor == par.getChildCount()) {
return null;
}
nextChild = par.getChild(cursor++);
} else { // backwards
if (cursor == 0) {
return null;
}
nextChild = par.getChild(--cursor);
}
} while (nextChild instanceof DocType);
// DocType is not an XPath node; can occur for /child::node()
NodeInfo curr = makeWrapper(nextChild, docWrapper, commonParent, ix);
ix += forwards ? 1 : -1;
return curr;
}
}
}