dtmmanagerdefault.java

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/*
 * 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: DTMManagerDefault.java,v 1.2.4.1 2005/09/15 08:15:02 suresh_emailid Exp $
 */
package com.sun.org.apache.xml.internal.dtm.ref;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXSource;
import javax.xml.transform.stream.StreamSource;

import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.dtm.DTMException;
import com.sun.org.apache.xml.internal.dtm.DTMFilter;
import com.sun.org.apache.xml.internal.dtm.DTMIterator;
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.dtm.ref.dom2dtm.DOM2DTM;
import com.sun.org.apache.xml.internal.dtm.ref.sax2dtm.SAX2DTM;
import com.sun.org.apache.xml.internal.dtm.ref.sax2dtm.SAX2RTFDTM;
import com.sun.org.apache.xml.internal.res.XMLErrorResources;
import com.sun.org.apache.xml.internal.res.XMLMessages;
import com.sun.org.apache.xml.internal.utils.PrefixResolver;
import com.sun.org.apache.xml.internal.utils.SystemIDResolver;
import com.sun.org.apache.xml.internal.utils.XMLReaderManager;
import com.sun.org.apache.xml.internal.utils.XMLStringFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;

import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

/**
 * The default implementation for the DTMManager.
 *
 * %REVIEW% There is currently a reentrancy issue, since the finalizer
 * for XRTreeFrag (which runs in the GC thread) wants to call
 * DTMManager.release(), and may do so at the same time that the main
 * transformation thread is accessing the manager. Our current solution is
 * to make most of the manager's methods <code>synchronized</code>.
 * Early tests suggest that doing so is not causing a significant
 * performance hit in Xalan. However, it should be noted that there
 * is a possible alternative solution: rewrite release() so it merely
 * posts a request for release onto a threadsafe queue, and explicitly
 * process that queue on an infrequent basis during main-thread
 * activity (eg, when getDTM() is invoked). The downside of that solution
 * would be a greater delay before the DTM's storage is actually released
 * for reuse.
 * */
public class DTMManagerDefault extends DTMManager
{
  //static final boolean JKESS_XNI_EXPERIMENT=true;

  /** Set this to true if you want a dump of the DTM after creation. */
  private static final boolean DUMPTREE = false;

  /** Set this to true if you want a basic diagnostics. */
  private static final boolean DEBUG = false;

  /**
   * Map from DTM identifier numbers to DTM objects that this manager manages.
   * One DTM may have several prefix numbers, if extended node indexing
   * is in use; in that case, m_dtm_offsets[] will used to control which
   * prefix maps to which section of the DTM.
   * 
   * This array grows as necessary; see addDTM().
   * 
   * This array grows as necessary; see addDTM(). Growth is uncommon... but
   * access needs to be blindingly fast since it's used in node addressing.
   */
  protected DTM m_dtms[] = new DTM[256];
	
  /** Map from DTM identifier numbers to offsets. For small DTMs with a 
   * single identifier, this will always be 0. In overflow addressing, where
   * additional identifiers are allocated to access nodes beyond the range of
   * a single Node Handle, this table is used to map the handle's node field
   * into the actual node identifier.
   * 
   * This array grows as necessary; see addDTM().
   * 
   * This array grows as necessary; see addDTM(). Growth is uncommon... but
   * access needs to be blindingly fast since it's used in node addressing.
   * (And at the moment, that includes accessing it from DTMDefaultBase,
   * which is why this is not Protected or Private.)
   */
  int m_dtm_offsets[] = new int[256];

  /**
   * The cache for XMLReader objects to be used if the user did not
   * supply an XMLReader for a SAXSource or supplied a StreamSource.
   */
  protected XMLReaderManager m_readerManager = null;
  
  /**
   * The default implementation of ContentHandler, DTDHandler and ErrorHandler.
   */
  protected DefaultHandler m_defaultHandler = new DefaultHandler();

  /**
   * Add a DTM to the DTM table. This convenience call adds it as the 
   * "base DTM ID", with offset 0. The other version of addDTM should 
   * be used if you want to add "extended" DTM IDs with nonzero offsets.
   *
   * @param dtm Should be a valid reference to a DTM.
   * @param id Integer DTM ID to be bound to this DTM
   */
  synchronized public void addDTM(DTM dtm, int id) {	addDTM(dtm,id,0); }

	
  /**
   * Add a DTM to the DTM table.
   *
   * @param dtm Should be a valid reference to a DTM.
   * @param id Integer DTM ID to be bound to this DTM.
   * @param offset Integer addressing offset. The internal DTM Node ID is
   * obtained by adding this offset to the node-number field of the 
   * public DTM Handle. For the first DTM ID accessing each DTM, this is 0;
   * for overflow addressing it will be a multiple of 1<<IDENT_DTM_NODE_BITS.
   */
  synchronized public void addDTM(DTM dtm, int id, int offset)
  {
		if(id>=IDENT_MAX_DTMS)
		{
			// TODO: %REVIEW% Not really the right error message.
	    throw new DTMException(XMLMessages.createXMLMessage(XMLErrorResources.ER_NO_DTMIDS_AVAIL, null)); //"No more DTM IDs are available!");			 
		}
		
		// We used to just allocate the array size to IDENT_MAX_DTMS.
		// But we expect to increase that to 16 bits, and I'm not willing
		// to allocate that much space unless needed. We could use one of our
		// handy-dandy Fast*Vectors, but this will do for now.
		// %REVIEW%
		int oldlen=m_dtms.length;
		if(oldlen<=id)
		{
			// Various growth strategies are possible. I think we don't want 
			// to over-allocate excessively, and I'm willing to reallocate
			// more often to get that. See also Fast*Vector classes.
			//
			// %REVIEW% Should throw a more diagnostic error if we go over the max...
			int newlen=Math.min((id+256),IDENT_MAX_DTMS);

			DTM new_m_dtms[] = new DTM[newlen];
			System.arraycopy(m_dtms,0,new_m_dtms,0,oldlen);
			m_dtms=new_m_dtms;
			int new_m_dtm_offsets[] = new int[newlen];
			System.arraycopy(m_dtm_offsets,0,new_m_dtm_offsets,0,oldlen);
			m_dtm_offsets=new_m_dtm_offsets;
		}
		
    m_dtms[id] = dtm;
		m_dtm_offsets[id]=offset;
    dtm.documentRegistration();
		// The DTM should have been told who its manager was when we created it.
		// Do we need to allow for adopting DTMs _not_ created by this manager?
  }

  /**
   * Get the first free DTM ID available. %OPT% Linear search is inefficient!
   */
  synchronized public int getFirstFreeDTMID()
  {
    int n = m_dtms.length;
    for (int i = 1; i < n; i++)
    {
      if(null == m_dtms[i])
      {
        return i;
      }
    }
		return n; // count on addDTM() to throw exception if out of range
  }

  /**
   * The default table for exandedNameID lookups.
   */
  private ExpandedNameTable m_expandedNameTable =
    new ExpandedNameTable();

  /**
   * Constructor DTMManagerDefault
   *
   */
  public DTMManagerDefault(){}


  /**
   * Get an instance of a DTM, loaded with the content from the
   * specified source.  If the unique flag is true, a new instance will
   * always be returned.  Otherwise it is up to the DTMManager to return a
   * new instance or an instance that it already created and may be being used
   * by someone else.
   * 
   * A bit of magic in this implementation: If the source is null, unique is true,
   * and incremental and doIndexing are both false, we return an instance of
   * SAX2RTFDTM, which see.
   * 
   * (I think more parameters will need to be added for error handling, and entity
   * resolution, and more explicit control of the RTF situation).
   *
   * @param source the specification of the source object.
   * @param unique true if the returned DTM must be unique, probably because it
   * is going to be mutated.
   * @param whiteSpaceFilter Enables filtering of whitespace nodes, and may
   *                         be null.
   * @param incremental true if the DTM should be built incrementally, if
   *                    possible.
   * @param doIndexing true if the caller considers it worth it to use
   *                   indexing schemes.
   *
   * @return a non-null DTM reference.
   */
  synchronized public DTM getDTM(Source source, boolean unique,
                                 DTMWSFilter whiteSpaceFilter,
                                 boolean incremental, boolean doIndexing)
  {

    if(DEBUG && null != source)
      System.out.println("Starting "+
                         (unique ? "UNIQUE" : "shared")+
                         " source: "+source.getSystemId()
                         );

    XMLStringFactory xstringFactory = m_xsf;
    int dtmPos = getFirstFreeDTMID();
    int documentID = dtmPos << IDENT_DTM_NODE_BITS;

    if ((null != source) && source instanceof DOMSource)
    {
      DOM2DTM dtm = new DOM2DTM(this, (DOMSource) source, documentID,
                                whiteSpaceFilter, xstringFactory, doIndexing);

      addDTM(dtm, dtmPos, 0);

      //      if (DUMPTREE)
      //      {
      //        dtm.dumpDTM();
      //      }

      return dtm;
    }
    else
    {
      boolean isSAXSource = (null != source)
        ? (source instanceof SAXSource) : true;
      boolean isStreamSource = (null != source)
        ? (source instanceof StreamSource) : false;

      if (isSAXSource || isStreamSource) {
        XMLReader reader = null;
        SAX2DTM dtm;

        try {
          InputSource xmlSource;

          if (null == source) {
            xmlSource = null;
          } else {
            reader = getXMLReader(source);
            xmlSource = SAXSource.sourceToInputSource(source);

            String urlOfSource = xmlSource.getSystemId();

            if (null != urlOfSource) {
              try {
                urlOfSource = SystemIDResolver.getAbsoluteURI(urlOfSource);
              } catch (Exception e) {
                // %REVIEW% Is there a better way to send a warning?
                System.err.println("Can not absolutize URL: " + urlOfSource);
              }

              xmlSource.setSystemId(urlOfSource);
            }
          }

          if (source==null && unique && !incremental && !doIndexing) {
            // Special case to support RTF construction into shared DTM.
            // It should actually still work for other uses,
            // but may be slightly deoptimized relative to the base
            // to allow it to deal with carrying multiple documents.
            //
            // %REVIEW% This is a sloppy way to request this mode;
            // we need to consider architectural improvements.
            dtm = new SAX2RTFDTM(this, source, documentID, whiteSpaceFilter,
                                 xstringFactory, doIndexing);
          }
          /**************************************************************
          // EXPERIMENTAL 3/22/02
          else if(JKESS_XNI_EXPERIMENT && m_incremental) {        	
            dtm = new XNI2DTM(this, source, documentID, whiteSpaceFilter,
                              xstringFactory, doIndexing);
          }
          **************************************************************/
          // Create the basic SAX2DTM.
          else {
            dtm = new SAX2DTM(this, source, documentID, whiteSpaceFilter,
                              xstringFactory, doIndexing);
          }

          // Go ahead and add the DTM to the lookup table.  This needs to be
          // done before any parsing occurs. Note offset 0, since we've just
          // created a new DTM.
          addDTM(dtm, dtmPos, 0);


          boolean haveXercesParser =
                     (null != reader)
                     && (reader.getClass()
                               .getName()
                               .equals("com.sun.org.apache.xerces.internal.parsers.SAXParser") );
        
          if (haveXercesParser) {
            incremental = true;  // No matter what.  %REVIEW%
          }
        
          // If the reader is null, but they still requested an incremental
          // build, then we still want to set up the IncrementalSAXSource stuff.
          if (m_incremental && incremental
               /* || ((null == reader) && incremental) */) {
            IncrementalSAXSource coParser=null;

            if (haveXercesParser) {
              // IncrementalSAXSource_Xerces to avoid threading.
              try {
                coParser =(IncrementalSAXSource)
                  Class.forName("com.sun.org.apache.xml.internal.dtm.ref.IncrementalSAXSource_Xerces").newInstance();  
              }  catch( Exception ex ) {
                ex.printStackTrace();
                coParser=null;
              }
            }

            if (coParser==null ) {
              // Create a IncrementalSAXSource to run on the secondary thread.
              if (null == reader) {
                coParser = new IncrementalSAXSource_Filter();
              } else {
                IncrementalSAXSource_Filter filter =
                         new IncrementalSAXSource_Filter();
                filter.setXMLReader(reader);
                coParser=filter;
              }
            }

			
            /**************************************************************
            // EXPERIMENTAL 3/22/02
            if (JKESS_XNI_EXPERIMENT && m_incremental &&
                  dtm instanceof XNI2DTM && 
                  coParser instanceof IncrementalSAXSource_Xerces) {
                com.sun.org.apache.xerces.internal.xni.parser.XMLPullParserConfiguration xpc=
                      ((IncrementalSAXSource_Xerces)coParser)
                                           .getXNIParserConfiguration();
              if (xpc!=null) {
                // Bypass SAX; listen to the XNI stream
                ((XNI2DTM)dtm).setIncrementalXNISource(xpc);
              } else {
                  // Listen to the SAX stream (will fail, diagnostically...)
                dtm.setIncrementalSAXSource(coParser);
              }
            } else
            ***************************************************************/
          
            // Have the DTM set itself up as IncrementalSAXSource's listener.
            dtm.setIncrementalSAXSource(coParser);

            if (null == xmlSource) {

              // Then the user will construct it themselves.
              return dtm;
            }

            if (null == reader.getErrorHandler()) {
              reader.setErrorHandler(dtm);
            }
            reader.setDTDHandler(dtm);

            try {
              // Launch parsing coroutine.  Launches a second thread,
              // if we're using IncrementalSAXSource.filter().

              coParser.startParse(xmlSource);
            } catch (RuntimeException re) {

              dtm.clearCoRoutine();

              throw re;
            } catch (Exception e) {

              dtm.clearCoRoutine();

              throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(e);
            }
          } else {
            if (null == reader) {

              // Then the user will construct it themselves.
              return dtm;
            }

            // not incremental
            reader.setContentHandler(dtm);
            reader.setDTDHandler(dtm);
            if (null == reader.getErrorHandler()) {
              reader.setErrorHandler(dtm);
            }

            try {