| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 468653 2006-10-28 07:07:05Z minchau $ |
| */ |
| package org.apache.xml.dtm.ref.sax2dtm; |
| |
| import javax.xml.transform.Source; |
| |
| import org.apache.xml.dtm.DTM; |
| import org.apache.xml.dtm.DTMManager; |
| import org.apache.xml.dtm.DTMWSFilter; |
| import org.apache.xml.utils.IntStack; |
| import org.apache.xml.utils.IntVector; |
| import org.apache.xml.utils.StringVector; |
| import org.apache.xml.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.) |
| //org.apache.xalan.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. |
| * |
| * @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; |
| } |
| } |