/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2007 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.dom;
import org.exist.numbering.NodeId;
import org.exist.storage.DBBroker;
import org.exist.xquery.Constants;
import org.exist.xquery.Expression;
import org.exist.xquery.XPathException;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import java.util.Iterator;
/**
* Collection of static methods operating on node sets.
*
* @author wolf
*/
public class NodeSetHelper {
/**
* For two given sets of potential parent and child nodes, find those nodes
* from the child set that actually have parents in the parent set, i.e. the
* parent-child relationship is true.
*
* The method returns either the matching descendant or ancestor nodes,
* depending on the mode constant.
*
* If mode is {@link NodeSet#DESCENDANT}, the returned node set will contain all
* child nodes found in this node set for each parent node. If mode is
* {@link NodeSet#ANCESTOR}, the returned set will contain those parent nodes, for
* which children have been found.
*
* @param dl
* a node set containing potential child nodes
* @param al
* a node set containing potential parent nodes
* @param mode
* selection mode
* @param contextId
* used to track context nodes when evaluating predicate
* expressions. If contextId != {@link Expression#NO_CONTEXT_ID},
* the current context will be added to each result of the
* selection.
*/
public static NodeSet selectParentChild(NodeSet dl, NodeSet al, int mode,
int contextId) {
ExtArrayNodeSet result = new ExtArrayNodeSet();
DocumentImpl lastDoc = null;
switch (mode) {
case NodeSet.DESCENDANT:
for (Iterator i = dl.iterator(); i.hasNext();) {
int sizeHint = Constants.NO_SIZE_HINT;
NodeProxy child = (NodeProxy) i.next();
if (lastDoc == null || child.getDocument() != lastDoc) {
lastDoc = child.getDocument();
sizeHint = dl.getSizeHint(lastDoc);
}
NodeProxy parent = al.parentWithChild(child, true, false,
NodeProxy.UNKNOWN_NODE_LEVEL);
if (parent != null) {
if (Expression.NO_CONTEXT_ID != contextId)
child.deepCopyContext(parent, contextId);
else
child.copyContext(parent);
result.add(child, sizeHint);
}
}
break;
case NodeSet.ANCESTOR:
for (Iterator i = dl.iterator(); i.hasNext();) {
int sizeHint = Constants.NO_SIZE_HINT;
NodeProxy child = (NodeProxy) i.next();
if (lastDoc == null || child.getDocument() != lastDoc) {
lastDoc = child.getDocument();
sizeHint = al.getSizeHint(lastDoc);
}
NodeProxy parent = al.parentWithChild(child, true, false,
NodeProxy.UNKNOWN_NODE_LEVEL);
if (parent != null) {
if (Expression.NO_CONTEXT_ID != contextId)
parent.deepCopyContext(child, contextId);
else
parent.copyContext(child);
parent.addMatches(child);
result.add(parent, sizeHint);
}
}
break;
default:
throw new IllegalArgumentException("Bad 'mode' argument");
}
result.sort();
return result;
}
/**
* For two given sets of potential ancestor and descendant nodes, find those
* nodes from the descendant set that actually have ancestors in the
* ancestor set, i.e. the ancestor-descendant relationship is true.
*
* The method returns either the matching descendant or ancestor nodes,
* depending on the mode constant.
*
* If mode is {@link NodeSet#DESCENDANT}, the returned node set will contain all
* descendant nodes found in this node set for each ancestor. If mode is
* {@link NodeSet#ANCESTOR}, the returned set will contain those ancestor nodes,
* for which descendants have been found.
*
* @param dl
* a node set containing potential descendant nodes
* @param al
* a node set containing potential ancestor nodes
* @param mode
* selection mode
* @param includeSelf
* if true, check if the ancestor node itself is contained in the
* set of descendant nodes (descendant-or-self axis)
* @param contextId
* used to track context nodes when evaluating predicate
* expressions. If contextId != {@link Expression#NO_CONTEXT_ID},
* the current context will be added to each result of the
* selection.
*
*/
public static NodeSet selectAncestorDescendant(NodeSet dl, NodeSet al,
int mode, boolean includeSelf, int contextId) {
ExtArrayNodeSet result = new ExtArrayNodeSet();
DocumentImpl lastDoc = null;
switch (mode) {
case NodeSet.DESCENDANT:
for (Iterator i = dl.iterator(); i.hasNext();) {
int sizeHint = Constants.NO_SIZE_HINT;
NodeProxy descendant = (NodeProxy) i.next();
// get a size hint for every new document encountered
if (lastDoc == null || descendant.getDocument() != lastDoc) {
lastDoc = descendant.getDocument();
sizeHint = dl.getSizeHint(lastDoc);
}
NodeProxy ancestor = al.parentWithChild(descendant.getDocument(),
descendant.getNodeId(),
false, includeSelf);
if (ancestor != null) {
if (Expression.NO_CONTEXT_ID != contextId)
descendant.addContextNode(contextId, ancestor);
else
descendant.copyContext(ancestor);
result.add(descendant, sizeHint);
}
}
break;
case NodeSet.ANCESTOR:
for (Iterator i = dl.iterator(); i.hasNext();) {
int sizeHint = Constants.NO_SIZE_HINT;
NodeProxy descendant = (NodeProxy) i.next();
// get a size hint for every new document encountered
if (lastDoc == null || descendant.getDocument() != lastDoc) {
lastDoc = descendant.getDocument();
sizeHint = al.getSizeHint(lastDoc);
}
NodeProxy ancestor = al.parentWithChild(descendant.getDocument(),
descendant.getNodeId(), false, includeSelf);
if (ancestor != null) {
if (Expression.NO_CONTEXT_ID != contextId)
ancestor.addContextNode(contextId, descendant);
else
ancestor.copyContext(descendant);
result.add(ancestor, sizeHint);
}
}
break;
default:
throw new IllegalArgumentException("Bad 'mode' argument");
}
return result;
}
/**
* For two sets of potential ancestor and descendant nodes, return all the
* real ancestors having a descendant in the descendant set.
*
* @param al
* node set containing potential ancestors
* @param dl
* node set containing potential descendants
* @param includeSelf
* if true, check if the ancestor node itself is contained in
* this node set (ancestor-or-self axis)
* @param contextId
* used to track context nodes when evaluating predicate
* expressions. If contextId != {@link Expression#NO_CONTEXT_ID},
* the current context will be added to each result of the of the
* selection.
*/
public static NodeSet selectAncestors(NodeSet al, NodeSet dl,
boolean includeSelf, int contextId) {
NodeSet result = new NewArrayNodeSet();
for (Iterator i = dl.iterator(); i.hasNext();) {
NodeProxy descendant = (NodeProxy) i.next();
NodeSet ancestors = ancestorsForChild(al, descendant, false, includeSelf);
for (Iterator j = ancestors.iterator(); j.hasNext();) {
NodeProxy ancestor = (NodeProxy) j.next();
if (ancestor != null) {
NodeProxy temp = result.get(ancestor);
if (temp == null) {
if (Expression.IGNORE_CONTEXT != contextId) {
if (Expression.NO_CONTEXT_ID != contextId)
ancestor.addContextNode(contextId, descendant);
else
ancestor.copyContext(descendant);
}
ancestor.addMatches(descendant);
result.add(ancestor);
} else if (Expression.NO_CONTEXT_ID != contextId) {
temp.addContextNode(contextId, descendant);
}
}
}
}
return result;
}
/**
* Return all nodes contained in the node set that are ancestors of the node
* p.
*/
private static NodeSet ancestorsForChild(NodeSet ancestors,
NodeProxy child, boolean directParent, boolean includeSelf) {
NodeSet result = new NewArrayNodeSet(5);
NodeId nodeId = child.getNodeId();
NodeProxy temp = ancestors.get(child.getDocument(), nodeId);
if (includeSelf && temp != null)
result.add(temp);
while (nodeId != null && nodeId != NodeId.DOCUMENT_NODE) {
nodeId = nodeId.getParentId();
temp = ancestors.get(child.getDocument(), nodeId);
if (temp != null)
result.add(temp);
else if (directParent)
return result;
}
return result;
}
/**
* Select all nodes from the passed set of potential siblings, which are
* preceding siblings of the nodes in the other set.
*
* @param candidates
* the node set to check
* @param references
* a node set containing potential siblings
* @param contextId
* used to track context nodes when evaluating predicate
* expressions. If contextId != {@link Expression#NO_CONTEXT_ID},
* the current context will be added to each result of the of the
* selection.
*/
public static NodeSet selectPrecedingSiblings(NodeSet candidates,
NodeSet references, int contextId) {
if (references.isEmpty() || candidates.isEmpty())
return NodeSet.EMPTY_SET;
NodeSet result = new ExtArrayNodeSet();
NodeSetIterator iReferences = references.iterator();
NodeSetIterator iCandidates = candidates.iterator();
NodeProxy reference = (NodeProxy) iReferences.next();
NodeProxy candidate = (NodeProxy) iCandidates.next();
NodeProxy firstCandidate = null;
while (true) {
// first, try to find nodes belonging to the same doc
if (reference.getDocument().getDocId() < candidate.getDocument()
.getDocId()) {
firstCandidate = null;
if (iReferences.hasNext())
reference = (NodeProxy) iReferences.next();
else
break;
} else if (reference.getDocument().getDocId() > candidate
.getDocument().getDocId()) {
firstCandidate = null;
if (iCandidates.hasNext())
candidate = (NodeProxy) iCandidates.next();
else
break;
} else {
// same document: check if the nodes have the same parent
int cmp = candidate.getNodeId().getParentId().compareTo(reference.getNodeId().getParentId());
if (cmp > 0 && candidate.getNodeId().getTreeLevel() <= reference.getNodeId().getTreeLevel()) {
// wrong parent: proceed
firstCandidate = null;
if (iReferences.hasNext())
reference = (NodeProxy) iReferences.next();
else
break;
} else if (cmp < 0 || (cmp > 0 && candidate.getNodeId().getTreeLevel() >= reference.getNodeId().getTreeLevel())) {
//Why did I have to invert the test ? ----------------------------^^^^^
// wrong parent: proceed
firstCandidate = null;
if (iCandidates.hasNext())
candidate = (NodeProxy) iCandidates.next();
else
break;
} else {
if (firstCandidate == null)
firstCandidate = candidate;
// found two nodes with the same parent
// now, compare the ids: a node is a following sibling
// if its id is greater than the id of the other node
cmp = candidate.getNodeId().compareTo(reference.getNodeId());
if (cmp < 0) {
// found a preceding sibling
NodeProxy t = result.get(candidate);
if (t == null) {
if (Expression.IGNORE_CONTEXT != contextId) {
if (Expression.NO_CONTEXT_ID == contextId) {
candidate.copyContext(reference);
} else {
candidate.addContextNode(contextId,
reference);
}
}
result.add(candidate);
} else if (contextId > Expression.NO_CONTEXT_ID){
t.addContextNode(contextId, reference);
}
if (iCandidates.hasNext())
candidate = (NodeProxy) iCandidates.next();
else
break;
} else if (cmp > 0) {
// found a following sibling
if (iCandidates.hasNext())
// TODO : break ?
candidate = (NodeProxy) iCandidates.next();
else
break;
// equal nodes: proceed with next node
} else {
if (iReferences.hasNext()) {
reference = (NodeProxy) iReferences.next();
iCandidates.setPosition(firstCandidate);
candidate = (NodeProxy) iCandidates.next();
} else
break;
}
}
}
}
return result;
}
/**
* Select all nodes from the passed set of potential siblings, which are
* following siblings of the nodes in the other set.
*
* @param candidates
* the node set to check
* @param references
* a node set containing potential siblings
* @param contextId
* used to track context nodes when evaluating predicate
* expressions. If contextId != {@link Expression#NO_CONTEXT_ID},
* the current context will be added to each result of the of the
* selection.
*/
public static NodeSet selectFollowingSiblings(NodeSet candidates,
NodeSet references, int contextId) {
if (references.isEmpty() || candidates.isEmpty())
return NodeSet.EMPTY_SET;
NodeSet result = new ExtArrayNodeSet();
NodeSetIterator iReferences = references.iterator();
NodeSetIterator iCandidates = candidates.iterator();
NodeProxy reference = (NodeProxy) iReferences.next();
NodeProxy candidate = (NodeProxy) iCandidates.next();
NodeProxy firstCandidate = null;
// TODO : review : don't care about preceding siblings
while (true) {
// first, try to find nodes belonging to the same doc
if (reference.getDocument().getDocId() < candidate.getDocument()
.getDocId()) {
firstCandidate = null;
if (iReferences.hasNext())
reference = (NodeProxy) iReferences.next();
else
break;
} else if (reference.getDocument().getDocId() > candidate
.getDocument().getDocId()) {
firstCandidate = null;
if (iCandidates.hasNext())
candidate = (NodeProxy) iCandidates.next();
else
break;
} else {
// same document: check if the nodes have the same parent
int cmp = candidate.getNodeId().getParentId().compareTo(reference.getNodeId().getParentId());
if (cmp > 0 && candidate.getNodeId().getTreeLevel() <= reference.getNodeId().getTreeLevel()) {
//Do not proceed to the next "parent" if the candidate is a descendant
// wrong parent: proceed
firstCandidate = null;
if (iReferences.hasNext())
reference = (NodeProxy) iReferences.next();
else
break;
} else if (cmp < 0 || (cmp > 0 && candidate.getNodeId().getTreeLevel() >= reference.getNodeId().getTreeLevel())) {
//Why did I have to invert the test ? ----------------------------^^^^^
// wrong parent: proceed
firstCandidate = null;
if (iCandidates.hasNext())
candidate = (NodeProxy) iCandidates.next();
else
break;
} else {
if (firstCandidate == null)
firstCandidate = candidate;
cmp = candidate.getNodeId().compareTo(reference.getNodeId());
// found two nodes with the same parent
// now, compare the ids: a node is a following sibling
// if its id is greater than the id of the other node
if (cmp < 0) {
// found a preceding sibling
if (iCandidates.hasNext())
candidate = (NodeProxy) iCandidates.next();
else
break;
} else if (cmp > 0) {
// found a following sibling
NodeProxy t = result.get(candidate);
if (t == null) {
if (Expression.IGNORE_CONTEXT != contextId) {
if (Expression.NO_CONTEXT_ID == contextId) {
candidate.copyContext(reference);
} else {
candidate.addContextNode(contextId,
reference);
}
}
result.add(candidate);
} else {
t.addContextNode(contextId, reference);
}
result.add(candidate);
if (iCandidates.hasNext())
candidate = (NodeProxy) iCandidates.next();
else if (iReferences.hasNext()) {
reference = (NodeProxy) iReferences.next();
iCandidates.setPosition(firstCandidate);
candidate = (NodeProxy) iCandidates.next();
}
else
break;
// equal nodes: proceed with next node
} else {
if (iCandidates.hasNext())
candidate = (NodeProxy) iCandidates.next();
else
break;
}
}
}
}
return result;
}
/**
* TODO: doesn't work!!!
*/
public static NodeSet selectPreceding(NodeSet references, NodeSet candidates)
throws XPathException {
if (candidates.isEmpty() || references.isEmpty())
return NodeSet.EMPTY_SET;
NodeSet result = new NewArrayNodeSet();
for (Iterator iReferences = references.iterator(); iReferences
.hasNext();) {
NodeProxy reference = (NodeProxy) iReferences.next();
for (Iterator iCandidates = candidates.iterator(); iCandidates
.hasNext();) {
NodeProxy candidate = (NodeProxy) iCandidates.next();
if (candidate.before(reference, true)) {
// TODO : add transverse context
candidate.addContextNode(Expression.NO_CONTEXT_ID,
reference);
result.add(candidate);
}
}
}
return result;
}
/**
* TODO: doesn't work!!!
*/
public static NodeSet selectFollowing(NodeSet references, NodeSet candidates)
throws XPathException {
if (candidates.isEmpty() || references.isEmpty())
return NodeSet.EMPTY_SET;
NodeSet result = new ExtArrayNodeSet();
for (Iterator iReferences = references.iterator(); iReferences
.hasNext();) {
NodeProxy reference = (NodeProxy) iReferences.next();
for (Iterator iCandidates = candidates.iterator(); iCandidates
.hasNext();) {
NodeProxy candidate = (NodeProxy) iCandidates.next();
if (candidate.after(reference, true)) {
// TODO : add transverse context
candidate.addContextNode(Expression.NO_CONTEXT_ID,
reference);
result.add(candidate);
}
}
}
return result;
}
public static NodeSet directSelectAttributes(DBBroker broker, NodeSet candidates,
org.exist.xquery.NodeTest test, int contextId) {
if (candidates.isEmpty())
return NodeSet.EMPTY_SET;
NodeSet result = new ExtArrayNodeSet();
for (Iterator iCandidates = candidates.iterator(); iCandidates
.hasNext();) {
NodeProxy candidate = (NodeProxy) iCandidates.next();
result.addAll(candidate.directSelectAttribute(broker, test, contextId));
}
return result;
}
public final static void copyChildren(Document new_doc, Node node,
Node new_node) {
NodeList children = node.getChildNodes();
Node new_child;
for (int i = 0; i < children.getLength(); i++) {
Node child = children.item(i);
if (child == null)
continue;
switch (child.getNodeType()) {
case Node.ELEMENT_NODE: {
new_child = copyNode(new_doc, child);
new_node.appendChild(new_child);
break;
}
case Node.ATTRIBUTE_NODE: {
new_child = copyNode(new_doc, child);
((Element) new_node).setAttributeNode((Attr) new_child);
break;
}
case Node.TEXT_NODE: {
new_child = copyNode(new_doc, child);
new_node.appendChild(new_child);
break;
}
// TODO : error for any other one -pb
}
}
}
public final static Node copyNode(Document new_doc, Node node) {
Node new_node;
switch (node.getNodeType()) {
case Node.ELEMENT_NODE:
new_node = new_doc.createElementNS(node.getNamespaceURI(), node
.getNodeName());
copyChildren(new_doc, node, new_node);
return new_node;
case Node.TEXT_NODE:
new_node = new_doc.createTextNode(((Text) node).getData());
return new_node;
case Node.ATTRIBUTE_NODE:
new_node = new_doc.createAttributeNS(node.getNamespaceURI(), node
.getNodeName());
((Attr) new_node).setValue(((Attr) node).getValue());
return new_node;
default:
// TODO : error ? -pb
return null;
}
}
}