Java example source code file (DTMManagerDefault.java)

This example Java source code file (DTMManagerDefault.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

dom, dom2dtm, domsource, dtm, dtmdefaultbase, dtmiterator, dtmmanagerdefault, exception, expandednametable, ident_dtm_node_bits, incrementalsaxsource_filter, node, parser, runtimeexception, sax, sax2dtm, xml, xmlreader

The DTMManagerDefault.java Java example source code

/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/*
 * 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 com.sun.org.apache.xalan.internal.utils.FactoryImpl;
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.
 * 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];
    }
    catch(java.lang.ArrayIndexOutOfBoundsException e)
    {
      if(nodeHandle==DTM.NULL)
                                return null;            // Accept as a special case.
      else
                                throw e;                // Programming error; want to know about it.
    }
  }

  /**
   * Given a DTM, find the ID number in the DTM tables which addresses
   * the start of the document. If overflow addressing is in use, other
   * DTM IDs may also be assigned to this DTM.
   *
   * @param dtm The DTM which (hopefully) contains this node.
   *
   * @return The DTM ID (as the high bits of a NodeHandle, not as our
   * internal index), or -1 if the DTM doesn't belong to this manager.
   */
  synchronized public int getDTMIdentity(DTM dtm)
  {
        // Shortcut using DTMDefaultBase's extension hooks
        // %REVIEW% Should the lookup be part of the basic DTM API?
        if(dtm instanceof DTMDefaultBase)
        {
                DTMDefaultBase dtmdb=(DTMDefaultBase)dtm;
                if(dtmdb.getManager()==this)
                        return dtmdb.getDTMIDs().elementAt(0);
                else
                        return -1;
        }

    int n = m_dtms.length;

    for (int i = 0; i < n; i++)
    {
      DTM tdtm = m_dtms[i];

      if (tdtm == dtm && m_dtm_offsets[i]==0)
        return i << IDENT_DTM_NODE_BITS;
    }

    return -1;
  }

  /**
   * Release the DTMManager's reference(s) to a DTM, making it unmanaged.
   * This is typically done as part of returning the DTM to the heap after
   * we're done with it.
   *
   * @param dtm the DTM to be released.
   *
   * @param shouldHardDelete If false, this call is a suggestion rather than an
   * order, and we may not actually release the DTM. This is intended to
   * support intelligent caching of documents... which is not implemented
   * in this version of the DTM manager.
   *
   * @return true if the DTM was released, false if shouldHardDelete was set
   * and we decided not to.
   */
  synchronized public boolean release(DTM dtm, boolean shouldHardDelete)
  {
    if(DEBUG)
    {
      System.out.println("Releasing "+
                         (shouldHardDelete ? "HARD" : "soft")+
                         " dtm="+
                         // Following shouldn't need a nodeHandle, but does...
                         // and doesn't seem to report the intended value
                         dtm.getDocumentBaseURI()
                         );
    }

    if (dtm instanceof SAX2DTM)
    {
      ((SAX2DTM) dtm).clearCoRoutine();
    }

                // Multiple DTM IDs may be assigned to a single DTM.
                // The Right Answer is to ask which (if it supports
                // extension, the DTM will need a list anyway). The
                // Wrong Answer, applied if the DTM can't help us,
                // is to linearly search them all; this may be very
                // painful.
                //
                // %REVIEW% Should the lookup move up into the basic DTM API?
                if(dtm instanceof DTMDefaultBase)
                {
                        com.sun.org.apache.xml.internal.utils.SuballocatedIntVector ids=((DTMDefaultBase)dtm).getDTMIDs();
                        for(int i=ids.size()-1;i>=0;--i)
                                m_dtms[ids.elementAt(i)>>>DTMManager.IDENT_DTM_NODE_BITS]=null;
                }
                else
                {
                        int i = getDTMIdentity(dtm);
                    if (i >= 0)
                        {
                                m_dtms[i >>> DTMManager.IDENT_DTM_NODE_BITS] = null;
                        }
                }

    dtm.documentRelease();
    return true;
  }

  /**
   * Method createDocumentFragment
   *
   *
   * NEEDSDOC (createDocumentFragment) @return
   */
  synchronized public DTM createDocumentFragment()
  {

    try
    {
      DocumentBuilderFactory dbf = FactoryImpl.getDOMFactory(super.useServicesMechnism());
      dbf.setNamespaceAware(true);

      DocumentBuilder db = dbf.newDocumentBuilder();
      Document doc = db.newDocument();
      Node df = doc.createDocumentFragment();

      return getDTM(new DOMSource(df), true, null, false, false);
    }
    catch (Exception e)
    {
      throw new DTMException(e);
    }
  }

  /**
   * NEEDSDOC Method createDTMIterator
   *
   *
   * NEEDSDOC @param whatToShow
   * NEEDSDOC @param filter
   * NEEDSDOC @param entityReferenceExpansion
   *
   * NEEDSDOC (createDTMIterator) @return
   */
  synchronized public DTMIterator createDTMIterator(int whatToShow, DTMFilter filter,
                                       boolean entityReferenceExpansion)
  {

    /** @todo: implement this com.sun.org.apache.xml.internal.dtm.DTMManager abstract method */
    return null;
  }

  /**
   * NEEDSDOC Method createDTMIterator
   *
   *
   * NEEDSDOC @param xpathString
   * NEEDSDOC @param presolver
   *
   * NEEDSDOC (createDTMIterator) @return
   */
  synchronized public DTMIterator createDTMIterator(String xpathString,
                                       PrefixResolver presolver)
  {

    /** @todo: implement this com.sun.org.apache.xml.internal.dtm.DTMManager abstract method */
    return null;
  }

  /**
   * NEEDSDOC Method createDTMIterator
   *
   *
   * NEEDSDOC @param node
   *
   * NEEDSDOC (createDTMIterator) @return
   */
  synchronized public DTMIterator createDTMIterator(int node)
  {

    /** @todo: implement this com.sun.org.apache.xml.internal.dtm.DTMManager abstract method */
    return null;
  }

  /**
   * NEEDSDOC Method createDTMIterator
   *
   *
   * NEEDSDOC @param xpathCompiler
   * NEEDSDOC @param pos
   *
   * NEEDSDOC (createDTMIterator) @return
   */
  synchronized public DTMIterator createDTMIterator(Object xpathCompiler, int pos)
  {

    /** @todo: implement this com.sun.org.apache.xml.internal.dtm.DTMManager abstract method */
    return null;
  }

  /**
   * return the expanded name table.
   *
   * NEEDSDOC @param dtm
   *
   * NEEDSDOC ($objectName$) @return
   */
  public ExpandedNameTable getExpandedNameTable(DTM dtm)
  {
    return m_expandedNameTable;
  }
}