- /*
- * Copyright 1999-2004 The Apache Software Foundation.
- *
- * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- /*
- * $Id: SAX2RTFDTM.java,v 1.9 2004/02/17 04:07:37 minchau Exp $
- */
- package com.sun.org.apache.xml.internal.dtm.ref.sax2dtm;
-
- import javax.xml.transform.Source;
-
- import com.sun.org.apache.xml.internal.dtm.DTM;
- import com.sun.org.apache.xml.internal.dtm.DTMManager;
- import com.sun.org.apache.xml.internal.dtm.DTMWSFilter;
- import com.sun.org.apache.xml.internal.utils.IntStack;
- import com.sun.org.apache.xml.internal.utils.IntVector;
- import com.sun.org.apache.xml.internal.utils.StringVector;
- import com.sun.org.apache.xml.internal.utils.XMLStringFactory;
-
- import org.xml.sax.SAXException;
-
- /**
- * This is a subclass of SAX2DTM which has been modified to meet the needs of
- * Result Tree Frameworks (RTFs). The differences are:
- *
- * 1) Multiple XML trees may be appended to the single DTM. This means
- * that the root node of each document is _not_ node 0. Some code has
- * had to be deoptimized to support this mode of operation, and an
- * explicit mechanism for obtaining the Node Handle of the root node
- * has been provided.
- *
- * 2) A stack of these documents is maintained, allowing us to "tail-prune" the
- * most recently added trees off the end of the DTM as stylesheet elements
- * (and thus variable contexts) are exited.
- *
- * PLEASE NOTE that this class may be _heavily_ dependent upon the
- * internals of the SAX2DTM superclass, and must be maintained in
- * parallel with that code. Arguably, they should be conditionals
- * within a single class... but they have deen separated for
- * performance reasons. (In fact, one could even argue about which is
- * the superclass and which is the subclass; the current arrangement
- * is as much about preserving stability of existing code during
- * development as anything else.)
- *
- * %REVIEW% In fact, since the differences are so minor, I think it
- * may be possible/practical to fold them back into the base
- * SAX2DTM. Consider that as a future code-size optimization.
- * */
- public class SAX2RTFDTM extends SAX2DTM
- {
- /** Set true to monitor SAX events and similar diagnostic info. */
- private static final boolean DEBUG = false;
-
- /** Most recently started Document, or null if the DTM is empty. */
- private int m_currentDocumentNode=NULL;
-
- /** Tail-pruning mark: Number of nodes in use */
- IntStack mark_size=new IntStack();
- /** Tail-pruning mark: Number of data items in use */
- IntStack mark_data_size=new IntStack();
- /** Tail-pruning mark: Number of size-of-data fields in use */
- IntStack mark_char_size=new IntStack();
- /** Tail-pruning mark: Number of dataOrQName slots in use */
- IntStack mark_doq_size=new IntStack();
- /** Tail-pruning mark: Number of namespace declaration sets in use
- * %REVIEW% I don't think number of NS sets is ever different from number
- * of NS elements. We can probabably reduce these to a single stack and save
- * some storage.
- * */
- IntStack mark_nsdeclset_size=new IntStack();
- /** Tail-pruning mark: Number of naespace declaration elements in use
- * %REVIEW% I don't think number of NS sets is ever different from number
- * of NS elements. We can probabably reduce these to a single stack and save
- * some storage.
- */
- IntStack mark_nsdeclelem_size=new IntStack();
-
- /**
- * Tail-pruning mark: initial number of nodes in use
- */
- int m_emptyNodeCount;
-
- /**
- * Tail-pruning mark: initial number of namespace declaration sets
- */
- int m_emptyNSDeclSetCount;
-
- /**
- * Tail-pruning mark: initial number of namespace declaration elements
- */
- int m_emptyNSDeclSetElemsCount;
-
- /**
- * Tail-pruning mark: initial number of data items in use
- */
- int m_emptyDataCount;
-
- /**
- * Tail-pruning mark: initial number of characters in use
- */
- int m_emptyCharsCount;
-
- /**
- * Tail-pruning mark: default initial number of dataOrQName slots in use
- */
- int m_emptyDataQNCount;
-
- public SAX2RTFDTM(DTMManager mgr, Source source, int dtmIdentity,
- DTMWSFilter whiteSpaceFilter,
- XMLStringFactory xstringfactory,
- boolean doIndexing)
- {
- super(mgr, source, dtmIdentity, whiteSpaceFilter,
- xstringfactory, doIndexing);
-
- // NEVER track source locators for RTFs; they aren't meaningful. I think.
- // (If we did track them, we'd need to tail-prune these too.)
- //com.sun.org.apache.xalan.internal.processor.TransformerFactoryImpl.m_source_location;
- m_useSourceLocationProperty=false;
- m_sourceSystemId = (m_useSourceLocationProperty) ? new StringVector()
- : null;
- m_sourceLine = (m_useSourceLocationProperty) ? new IntVector() : null;
- m_sourceColumn = (m_useSourceLocationProperty) ? new IntVector() : null;
-
- // Record initial sizes of fields that are pushed and restored
- // for RTF tail-pruning. More entries can be popped than pushed, so
- // we need this to mark the primordial state of the DTM.
- m_emptyNodeCount = m_size;
- m_emptyNSDeclSetCount = (m_namespaceDeclSets == null)
- ? 0 : m_namespaceDeclSets.size();
- m_emptyNSDeclSetElemsCount = (m_namespaceDeclSetElements == null)
- ? 0 : m_namespaceDeclSetElements.size();
- m_emptyDataCount = m_data.size();
- m_emptyCharsCount = m_chars.size();
- m_emptyDataQNCount = m_dataOrQName.size();
- }
-
- /**
- * Given a DTM, find the owning document node. In the case of
- * SAX2RTFDTM, which may contain multiple documents, this returns
- * the <b>most recently started</b> document, or null if the DTM is
- * empty or no document is currently under construction.
- *
- * %REVIEW% Should we continue to report the most recent after
- * construction has ended? I think not, given that it may have been
- * tail-pruned.
- *
- * @param nodeHandle the id of the node.
- * @return int Node handle of Document node, or null if this DTM does not
- * contain an "active" document.
- * */
- public int getDocument()
- {
- return makeNodeHandle(m_currentDocumentNode);
- }
-
- /**
- * Given a node handle, find the owning document node, using DTM semantics
- * (Document owns itself) rather than DOM semantics (Document has no owner).
- *
- * (I'm counting on the fact that getOwnerDocument() is implemented on top
- * of this call, in the superclass, to avoid having to rewrite that one.
- * Be careful if that code changes!)
- *
- * @param nodeHandle the id of the node.
- * @return int Node handle of owning document
- */
- public int getDocumentRoot(int nodeHandle)
- {
- for (int id=makeNodeIdentity(nodeHandle); id!=NULL; id=_parent(id)) {
- if (_type(id)==DTM.DOCUMENT_NODE) {
- return makeNodeHandle(id);
- }
- }
-
- return DTM.NULL; // Safety net; should never happen
- }
-
- /**
- * Given a node identifier, find the owning document node. Unlike the DOM,
- * this considers the owningDocument of a Document to be itself. Note that
- * in shared DTMs this may not be zero.
- *
- * @param nodeIdentifier the id of the starting node.
- * @return int Node identifier of the root of this DTM tree
- */
- protected int _documentRoot(int nodeIdentifier)
- {
- if(nodeIdentifier==NULL) return NULL;
-
- for (int parent=_parent(nodeIdentifier);
- parent!=NULL;
- nodeIdentifier=parent,parent=_parent(nodeIdentifier))
- ;
-
- return nodeIdentifier;
- }
-
- /**
- * Receive notification of the beginning of a new RTF document.
- *
- * %REVIEW% Y'know, this isn't all that much of a deoptimization. We
- * might want to consider folding the start/endDocument changes back
- * into the main SAX2DTM so we don't have to expose so many fields
- * (even as Protected) and carry the additional code.
- *
- * @throws SAXException Any SAX exception, possibly
- * wrapping another exception.
- * @see org.xml.sax.ContentHandler#startDocument
- * */
- public void startDocument() throws SAXException
- {
- // Re-initialize the tree append process
- m_endDocumentOccured = false;
- m_prefixMappings = new java.util.Vector();
- m_contextIndexes = new IntStack();
- m_parents = new IntStack();
-
- m_currentDocumentNode=m_size;
- super.startDocument();
- }
-
- /**
- * Receive notification of the end of the document.
- *
- * %REVIEW% Y'know, this isn't all that much of a deoptimization. We
- * might want to consider folding the start/endDocument changes back
- * into the main SAX2DTM so we don't have to expose so many fields
- * (even as Protected).
- *
- * @throws SAXException Any SAX exception, possibly
- * wrapping another exception.
- * @see org.xml.sax.ContentHandler#endDocument
- * */
- public void endDocument() throws SAXException
- {
- charactersFlush();
-
- m_nextsib.setElementAt(NULL,m_currentDocumentNode);
-
- if (m_firstch.elementAt(m_currentDocumentNode) == NOTPROCESSED)
- m_firstch.setElementAt(NULL,m_currentDocumentNode);
-
- if (DTM.NULL != m_previous)
- m_nextsib.setElementAt(DTM.NULL,m_previous);
-
- m_parents = null;
- m_prefixMappings = null;
- m_contextIndexes = null;
-
- m_currentDocumentNode= NULL; // no longer open
- m_endDocumentOccured = true;
- }
-
-
- /** "Tail-pruning" support for RTFs.
- *
- * This function pushes information about the current size of the
- * DTM's data structures onto a stack, for use by popRewindMark()
- * (which see).
- *
- * %REVIEW% I have no idea how to rewind m_elemIndexes. However,
- * RTFs will not be indexed, so I can simply panic if that case
- * arises. Hey, it works...
- * */
- public void pushRewindMark()
- {
- if(m_indexing || m_elemIndexes!=null)
- throw new java.lang.NullPointerException("Coding error; Don't try to mark/rewind an indexed DTM");
-
- // Values from DTMDefaultBase
- // %REVIEW% Can the namespace stack sizes ever differ? If not, save space!
- mark_size.push(m_size);
- mark_nsdeclset_size.push((m_namespaceDeclSets==null)
- ? 0
- : m_namespaceDeclSets.size());
- mark_nsdeclelem_size.push((m_namespaceDeclSetElements==null)
- ? 0
- : m_namespaceDeclSetElements.size());
-
- // Values from SAX2DTM
- mark_data_size.push(m_data.size());
- mark_char_size.push(m_chars.size());
- mark_doq_size.push(m_dataOrQName.size());
- }
-
- /** "Tail-pruning" support for RTFs.
- *
- * This function pops the information previously saved by
- * pushRewindMark (which see) and uses it to discard all nodes added
- * to the DTM after that time. We expect that this will allow us to
- * reuse storage more effectively.
- *
- * This is _not_ intended to be called while a document is still being
- * constructed -- only between endDocument and the next startDocument
- *
- * %REVIEW% WARNING: This is the first use of some of the truncation
- * methods. If Xalan blows up after this is called, that's a likely
- * place to check.
- *
- * %REVIEW% Our original design for DTMs permitted them to share
- * string pools. If there any risk that this might be happening, we
- * can _not_ rewind and recover the string storage. One solution
- * might to assert that DTMs used for RTFs Must Not take advantage
- * of that feature, but this seems excessively fragile. Another, much
- * less attractive, would be to just let them leak... Nah.
- *
- * @return true if and only if the pop completely emptied the
- * RTF. That response is used when determining how to unspool
- * RTF-started-while-RTF-open situations.
- * */
- public boolean popRewindMark()
- {
- boolean top=mark_size.empty();
-
- m_size=top ? m_emptyNodeCount : mark_size.pop();
- m_exptype.setSize(m_size);
- m_firstch.setSize(m_size);
- m_nextsib.setSize(m_size);
- m_prevsib.setSize(m_size);
- m_parent.setSize(m_size);
-
- m_elemIndexes=null;
-
- int ds= top ? m_emptyNSDeclSetCount : mark_nsdeclset_size.pop();
- if (m_namespaceDeclSets!=null) {
- m_namespaceDeclSets.setSize(ds);
- }
-
- int ds1= top ? m_emptyNSDeclSetElemsCount : mark_nsdeclelem_size.pop();
- if (m_namespaceDeclSetElements!=null) {
- m_namespaceDeclSetElements.setSize(ds1);
- }
-
- // Values from SAX2DTM - m_data always has a reserved entry
- m_data.setSize(top ? m_emptyDataCount : mark_data_size.pop());
- m_chars.setLength(top ? m_emptyCharsCount : mark_char_size.pop());
- m_dataOrQName.setSize(top ? m_emptyDataQNCount : mark_doq_size.pop());
-
- // Return true iff DTM now empty
- return m_size==0;
- }
-
- /** @return true if a DTM tree is currently under construction.
- * */
- public boolean isTreeIncomplete()
- {
- return !m_endDocumentOccured;
- }
- }