/* * 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. * *

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.

* *

An instance of this class must 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.

* *

Note: this class is incomplete right now. It will be pretty much * modeled after javax.xml.transform.TransformerFactory in terms of its * factory support.

* *

State: In progress!!

*/ 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 DTMManager. * This static method creates a new factory instance * This method uses the following ordered lookup procedure to determine * the DTMManager implementation class to * load: * * * Once an application has obtained a reference to a * DTMManager 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 DocumentFragment 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 DTMIterator based on an XPath * UnionExpr. * * @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 DTMIterator. */ public abstract DTMIterator createDTMIterator(Object xpathCompiler, int pos); /** * Create a new DTMIterator based on an XPath * UnionExpr. * * @param xpathString Must be a valid string expressing a * UnionExpr. * * @param presolver An object that can resolve prefixes to namespace URLs. * * @return The newly created DTMIterator. */ public abstract DTMIterator createDTMIterator(String xpathString, PrefixResolver presolver); /** * Create a new DTMIterator based only on a whatToShow * and a DTMFilter. The traversal semantics are defined as the * descendant access. *

* 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 NodeFilter for the set of possible * SHOW_ values.These flags can be combined using * OR. * @param filter The NodeFilter to be used with this * DTMFilter, or null to indicate no filter. * @param entityReferenceExpansion The value of this flag determines * whether entity reference nodes are expanded. * * @return The newly created DTMIterator. */ public abstract DTMIterator createDTMIterator(int whatToShow, DTMFilter filter, boolean entityReferenceExpansion); /** * Create a new DTMIterator that holds exactly one node. * * @param node The node handle that the DTMIterator will iterate to. * * @return The newly created DTMIterator. */ 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; /** * %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; } }