- /*
- * 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: DTMManager.java,v 1.18 2004/02/23 10:29:36 aruny Exp $
- */
- package com.sun.org.apache.xml.internal.dtm;
-
- 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.XMLStringFactory;
-
- /**
- * A DTMManager instance can be used to create DTM and
- * DTMIterator objects, and manage the DTM objects in the system.
- *
- * <p>The system property that determines which Factory implementation
- * to create is named "com.sun.org.apache.xml.internal.utils.DTMFactory". This
- * property names a concrete subclass of the DTMFactory abstract
- * class. If the property is not defined, a platform default is be used.</p>
- *
- * <p>An instance of this class <emph>must</emph> be safe to use across
- * thread instances. It is expected that a client will create a single instance
- * of a DTMManager to use across multiple threads. This will allow sharing
- * of DTMs across multiple processes.</p>
- *
- * <p>Note: this class is incomplete right now. It will be pretty much
- * modeled after javax.xml.transform.TransformerFactory in terms of its
- * factory support.</p>
- *
- * <p>State: In progress!!</p>
- */
- public abstract class DTMManager
- {
-
- /** The default property name to load the manager. */
- private static final String defaultPropName =
- "com.sun.org.apache.xml.internal.dtm.DTMManager";
-
- /** The default class name to use as the manager. */
- private static String defaultClassName =
- "com.sun.org.apache.xml.internal.dtm.ref.DTMManagerDefault";
-
- /**
- * Factory for creating XMLString objects.
- * %TBD% Make this set by the caller.
- */
- protected XMLStringFactory m_xsf = null;
-
- /**
- * Default constructor is protected on purpose.
- */
- protected DTMManager(){}
-
- /**
- * Get the XMLStringFactory used for the DTMs.
- *
- *
- * @return a valid XMLStringFactory object, or null if it hasn't been set yet.
- */
- public XMLStringFactory getXMLStringFactory()
- {
- return m_xsf;
- }
-
- /**
- * Set the XMLStringFactory used for the DTMs.
- *
- *
- * @param xsf a valid XMLStringFactory object, should not be null.
- */
- public void setXMLStringFactory(XMLStringFactory xsf)
- {
- m_xsf = xsf;
- }
-
- /**
- * Obtain a new instance of a <code>DTMManager</code>.
- * This static method creates a new factory instance
- * This method uses the following ordered lookup procedure to determine
- * the <code>DTMManager</code> implementation class to
- * load:
- * <ul>
- * <li>
- * Use the <code>com.sun.org.apache.xml.internal.dtm.DTMManager</code> system
- * property.
- * </li>
- * <li>
- * Use the JAVA_HOME(the parent directory where jdk is
- * installed)/lib/xalan.properties for a property file that contains the
- * name of the implementation class keyed on the same value as the
- * system property defined above.
- * </li>
- * <li>
- * Use the Services API (as detailed in the JAR specification), if
- * available, to determine the classname. The Services API will look
- * for a classname in the file
- * <code>META-INF/services/com.sun.org.apache.xml.internal.dtm.DTMManager</code>
- * in jars available to the runtime.
- * </li>
- * <li>
- * Use the default <code>DTMManager</code> classname, which is
- * <code>com.sun.org.apache.xml.internal.dtm.ref.DTMManagerDefault</code>.
- * </li>
- * </ul>
- *
- * Once an application has obtained a reference to a <code>
- * DTMManager</code> it can use the factory to configure
- * and obtain parser instances.
- *
- * @return new DTMManager instance, never null.
- *
- * @throws DTMConfigurationException
- * if the implementation is not available or cannot be instantiated.
- */
- public static DTMManager newInstance(XMLStringFactory xsf)
- throws DTMConfigurationException
- {
- DTMManager factoryImpl = null;
- try
- {
- factoryImpl = (DTMManager) ObjectFactory
- .createObject(defaultPropName, defaultClassName);
- }
- catch (ObjectFactory.ConfigurationError e)
- {
- throw new DTMConfigurationException(XMLMessages.createXMLMessage(
- XMLErrorResources.ER_NO_DEFAULT_IMPL, null), e.getException());
- //"No default implementation found");
- }
-
- if (factoryImpl == null)
- {
- throw new DTMConfigurationException(XMLMessages.createXMLMessage(
- XMLErrorResources.ER_NO_DEFAULT_IMPL, null));
- //"No default implementation found");
- }
-
- factoryImpl.setXMLStringFactory(xsf);
-
- return factoryImpl;
- }
-
- /**
- * 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.
- *
- * (More parameters may eventually need to be added for error handling
- * and entity resolution, and to better control selection of implementations.)
- *
- * @param source the specification of the source object, which may be null,
- * in which case it is assumed that node construction will take
- * by some other means.
- * @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.
- */
- public abstract DTM getDTM(javax.xml.transform.Source source,
- boolean unique, DTMWSFilter whiteSpaceFilter,
- boolean incremental, boolean doIndexing);
-
- /**
- * Get the instance of DTM that "owns" a node handle.
- *
- * @param nodeHandle the nodeHandle.
- *
- * @return a non-null DTM reference.
- */
- public abstract DTM getDTM(int nodeHandle);
-
- /**
- * Given a W3C DOM node, try and return a DTM handle.
- * Note: calling this may be non-optimal.
- *
- * @param node Non-null reference to a DOM node.
- *
- * @return a valid DTM handle.
- */
- public abstract int getDTMHandleFromNode(org.w3c.dom.Node node);
-
- /**
- * Creates a DTM representing an empty <code>DocumentFragment</code> object.
- * @return a non-null DTM reference.
- */
- public abstract DTM createDocumentFragment();
-
- /**
- * Release a DTM either to a lru pool, or completely remove reference.
- * DTMs without system IDs are always hard deleted.
- * State: experimental.
- *
- * @param dtm The DTM to be released.
- * @param shouldHardDelete True if the DTM should be removed no matter what.
- * @return true if the DTM was removed, false if it was put back in a lru pool.
- */
- public abstract boolean release(DTM dtm, boolean shouldHardDelete);
-
- /**
- * Create a new <code>DTMIterator</code> based on an XPath
- * <a href="http://www.w3.org/TR/xpath#NT-LocationPath>LocationPath</a> or
- * a <a href="http://www.w3.org/TR/xpath#NT-UnionExpr">UnionExpr</a>.
- *
- * @param xpathCompiler ??? Somehow we need to pass in a subpart of the
- * expression. I hate to do this with strings, since the larger expression
- * has already been parsed.
- *
- * @param pos The position in the expression.
- * @return The newly created <code>DTMIterator</code>.
- */
- public abstract DTMIterator createDTMIterator(Object xpathCompiler,
- int pos);
-
- /**
- * Create a new <code>DTMIterator</code> based on an XPath
- * <a href="http://www.w3.org/TR/xpath#NT-LocationPath>LocationPath</a> or
- * a <a href="http://www.w3.org/TR/xpath#NT-UnionExpr">UnionExpr</a>.
- *
- * @param xpathString Must be a valid string expressing a
- * <a href="http://www.w3.org/TR/xpath#NT-LocationPath>LocationPath</a> or
- * a <a href="http://www.w3.org/TR/xpath#NT-UnionExpr">UnionExpr</a>.
- *
- * @param presolver An object that can resolve prefixes to namespace URLs.
- *
- * @return The newly created <code>DTMIterator</code>.
- */
- public abstract DTMIterator createDTMIterator(String xpathString,
- PrefixResolver presolver);
-
- /**
- * Create a new <code>DTMIterator</code> based only on a whatToShow
- * and a DTMFilter. The traversal semantics are defined as the
- * descendant access.
- * <p>
- * Note that DTMIterators may not be an exact match to DOM
- * NodeIterators. They are initialized and used in much the same way
- * as a NodeIterator, but their response to document mutation is not
- * currently defined.
- *
- * @param whatToShow This flag specifies which node types may appear in
- * the logical view of the tree presented by the iterator. See the
- * description of <code>NodeFilter</code> for the set of possible
- * <code>SHOW_</code> values.These flags can be combined using
- * <code>OR</code>.
- * @param filter The <code>NodeFilter</code> to be used with this
- * <code>DTMFilter</code>, or <code>null</code> to indicate no filter.
- * @param entityReferenceExpansion The value of this flag determines
- * whether entity reference nodes are expanded.
- *
- * @return The newly created <code>DTMIterator</code>.
- */
- public abstract DTMIterator createDTMIterator(int whatToShow,
- DTMFilter filter, boolean entityReferenceExpansion);
-
- /**
- * Create a new <code>DTMIterator</code> that holds exactly one node.
- *
- * @param node The node handle that the DTMIterator will iterate to.
- *
- * @return The newly created <code>DTMIterator</code>.
- */
- public abstract DTMIterator createDTMIterator(int node);
-
- /* Flag indicating whether an incremental transform is desired */
- public static boolean m_incremental = false;
-
- /**
- * Set a flag indicating whether an incremental transform is desired
- * @param incremental boolean to use to set m_incremental.
- *
- */
- public synchronized static boolean getIncremental()
- {
- return m_incremental;
- }
-
- /**
- * Set a flag indicating whether an incremental transform is desired
- * @param incremental boolean to use to set m_incremental.
- *
- */
- public synchronized static void setIncremental(boolean incremental)
- {
- m_incremental = incremental;
- }
-
-
-
- // -------------------- private methods --------------------
-
- /**
- * Temp debug code - this will be removed after we test everything
- */
- private static boolean debug;
-
- static
- {
- try
- {
- debug = System.getProperty("dtm.debug") != null;
- }
- catch (SecurityException ex){}
- }
-
- /** This value, set at compile time, controls how many bits of the
- * DTM node identifier numbers are used to identify a node within a
- * document, and thus sets the maximum number of nodes per
- * document. The remaining bits are used to identify the DTM
- * document which contains this node.
- *
- * If you change IDENT_DTM_NODE_BITS, be sure to rebuild _ALL_ the
- * files which use it... including the IDKey testcases.
- *
- * (FuncGenerateKey currently uses the node identifier directly and
- * thus is affected when this changes. The IDKEY results will still be
- * _correct_ (presuming no other breakage), but simple equality
- * comparison against the previous "golden" files will probably
- * complain.)
- * */
- public static final int IDENT_DTM_NODE_BITS = 16;
-
-
- /** When this bitmask is ANDed with a DTM node handle number, the result
- * is the low bits of the node's index number within that DTM. To obtain
- * the high bits, add the DTM ID portion's offset as assigned in the DTM
- * Manager.
- */
- public static final int IDENT_NODE_DEFAULT = (1<<IDENT_DTM_NODE_BITS)-1;
-
-
- /** When this bitmask is ANDed with a DTM node handle number, the result
- * is the DTM's document identity number.
- */
- public static final int IDENT_DTM_DEFAULT = ~IDENT_NODE_DEFAULT;
-
- /** This is the maximum number of DTMs available. The highest DTM is
- * one less than this.
- */
- public static final int IDENT_MAX_DTMS = (IDENT_DTM_DEFAULT >>> IDENT_DTM_NODE_BITS) + 1;
-
-
- /**
- * %TBD% Doc
- *
- * NEEDSDOC @param dtm
- *
- * NEEDSDOC ($objectName$) @return
- */
- public abstract int getDTMIdentity(DTM dtm);
-
- /**
- * %TBD% Doc
- *
- * NEEDSDOC ($objectName$) @return
- */
- public int getDTMIdentityMask()
- {
- return IDENT_DTM_DEFAULT;
- }
-
- /**
- * %TBD% Doc
- *
- * NEEDSDOC ($objectName$) @return
- */
- public int getNodeIdentityMask()
- {
- return IDENT_NODE_DEFAULT;
- }
-
- }