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Diffstat (limited to 'src/com/sun/org/apache/xml/internal/utils/NamespaceSupport2.java')
| -rw-r--r-- | src/com/sun/org/apache/xml/internal/utils/NamespaceSupport2.java | 751 |
1 files changed, 0 insertions, 751 deletions
diff --git a/src/com/sun/org/apache/xml/internal/utils/NamespaceSupport2.java b/src/com/sun/org/apache/xml/internal/utils/NamespaceSupport2.java deleted file mode 100644 index 80a8161..0000000 --- a/src/com/sun/org/apache/xml/internal/utils/NamespaceSupport2.java +++ /dev/null @@ -1,751 +0,0 @@ -/* - * 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: NamespaceSupport2.java,v 1.3 2005/09/28 13:49:20 pvedula Exp $ - */ -package com.sun.org.apache.xml.internal.utils; - -import java.util.EmptyStackException; -import java.util.Enumeration; -import java.util.Hashtable; -import java.util.Vector; - -/** - * Encapsulate Namespace tracking logic for use by SAX drivers. - * - * <p>This class is an attempt to rewrite the SAX NamespaceSupport - * "helper" class for improved efficiency. It can be used to track the - * namespace declarations currently in scope, providing lookup - * routines to map prefixes to URIs and vice versa.</p> - * - * <p>ISSUE: For testing purposes, I've extended NamespaceSupport even - * though I'm completely reasserting all behaviors and fields. - * Wasteful.... But SAX did not put an interface under that object and - * we seem to have written that SAX class into our APIs... and I don't - * want to argue with it right now. </p> - * - * @see org.xml.sax.helpers.NamespaceSupport - * */ -public class NamespaceSupport2 - extends org.xml.sax.helpers.NamespaceSupport -{ - //////////////////////////////////////////////////////////////////// - // Internal state. - //////////////////////////////////////////////////////////////////// - - private Context2 currentContext; // Current point on the double-linked stack - - - //////////////////////////////////////////////////////////////////// - // Constants. - //////////////////////////////////////////////////////////////////// - - - /** - * The XML Namespace as a constant. - * - * <p>This is the Namespace URI that is automatically mapped - * to the "xml" prefix.</p> - */ - public final static String XMLNS = - "http://www.w3.org/XML/1998/namespace"; - - - //////////////////////////////////////////////////////////////////// - // Constructor. - //////////////////////////////////////////////////////////////////// - - - /** - * Create a new Namespace support object. - */ - public NamespaceSupport2 () - { - reset(); - } - - - //////////////////////////////////////////////////////////////////// - // Context management. - //////////////////////////////////////////////////////////////////// - - - /** - * Reset this Namespace support object for reuse. - * - * <p>It is necessary to invoke this method before reusing the - * Namespace support object for a new session.</p> - */ - public void reset () - { - // Discarding the whole stack doesn't save us a lot versus - // creating a new NamespaceSupport. Do we care, or should we - // change this to just reset the root context? - currentContext = new Context2(null); - currentContext.declarePrefix("xml", XMLNS); - } - - - /** - * Start a new Namespace context. - * - * <p>Normally, you should push a new context at the beginning - * of each XML element: the new context will automatically inherit - * the declarations of its parent context, but it will also keep - * track of which declarations were made within this context.</p> - * - * <p>The Namespace support object always starts with a base context - * already in force: in this context, only the "xml" prefix is - * declared.</p> - * - * @see #popContext - */ - public void pushContext () - { - // JJK: Context has a parent pointer. - // That means we don't need a stack to pop. - // We may want to retain for reuse, but that can be done via - // a child pointer. - - Context2 parentContext=currentContext; - currentContext = parentContext.getChild(); - if (currentContext == null){ - currentContext = new Context2(parentContext); - } - else{ - // JJK: This will wipe out any leftover data - // if we're reusing a previously allocated Context. - currentContext.setParent(parentContext); - } - } - - - /** - * Revert to the previous Namespace context. - * - * <p>Normally, you should pop the context at the end of each - * XML element. After popping the context, all Namespace prefix - * mappings that were previously in force are restored.</p> - * - * <p>You must not attempt to declare additional Namespace - * prefixes after popping a context, unless you push another - * context first.</p> - * - * @see #pushContext - */ - public void popContext () - { - Context2 parentContext=currentContext.getParent(); - if(parentContext==null) - throw new EmptyStackException(); - else - currentContext = parentContext; - } - - - - //////////////////////////////////////////////////////////////////// - // Operations within a context. - //////////////////////////////////////////////////////////////////// - - - /** - * Declare a Namespace prefix. - * - * <p>This method declares a prefix in the current Namespace - * context; the prefix will remain in force until this context - * is popped, unless it is shadowed in a descendant context.</p> - * - * <p>To declare a default Namespace, use the empty string. The - * prefix must not be "xml" or "xmlns".</p> - * - * <p>Note that you must <em>not</em> declare a prefix after - * you've pushed and popped another Namespace.</p> - * - * <p>Note that there is an asymmetry in this library: while {@link - * #getPrefix getPrefix} will not return the default "" prefix, - * even if you have declared one; to check for a default prefix, - * you have to look it up explicitly using {@link #getURI getURI}. - * This asymmetry exists to make it easier to look up prefixes - * for attribute names, where the default prefix is not allowed.</p> - * - * @param prefix The prefix to declare, or null for the empty - * string. - * @param uri The Namespace URI to associate with the prefix. - * @return true if the prefix was legal, false otherwise - * @see #processName - * @see #getURI - * @see #getPrefix - */ - public boolean declarePrefix (String prefix, String uri) - { - if (prefix.equals("xml") || prefix.equals("xmlns")) { - return false; - } else { - currentContext.declarePrefix(prefix, uri); - return true; - } - } - - - /** - * Process a raw XML 1.0 name. - * - * <p>This method processes a raw XML 1.0 name in the current - * context by removing the prefix and looking it up among the - * prefixes currently declared. The return value will be the - * array supplied by the caller, filled in as follows:</p> - * - * <dl> - * <dt>parts[0]</dt> - * <dd>The Namespace URI, or an empty string if none is - * in use.</dd> - * <dt>parts[1]</dt> - * <dd>The local name (without prefix).</dd> - * <dt>parts[2]</dt> - * <dd>The original raw name.</dd> - * </dl> - * - * <p>All of the strings in the array will be internalized. If - * the raw name has a prefix that has not been declared, then - * the return value will be null.</p> - * - * <p>Note that attribute names are processed differently than - * element names: an unprefixed element name will received the - * default Namespace (if any), while an unprefixed element name - * will not.</p> - * - * @param qName The raw XML 1.0 name to be processed. - * @param parts A string array supplied by the caller, capable of - * holding at least three members. - * @param isAttribute A flag indicating whether this is an - * attribute name (true) or an element name (false). - * @return The supplied array holding three internalized strings - * representing the Namespace URI (or empty string), the - * local name, and the raw XML 1.0 name; or null if there - * is an undeclared prefix. - * @see #declarePrefix - * @see java.lang.String#intern */ - public String [] processName (String qName, String[] parts, - boolean isAttribute) - { - String[] name=currentContext.processName(qName, isAttribute); - if(name==null) - return null; - - // JJK: This recopying is required because processName may return - // a cached result. I Don't Like It. ***** - System.arraycopy(name,0,parts,0,3); - return parts; - } - - - /** - * Look up a prefix and get the currently-mapped Namespace URI. - * - * <p>This method looks up the prefix in the current context. - * Use the empty string ("") for the default Namespace.</p> - * - * @param prefix The prefix to look up. - * @return The associated Namespace URI, or null if the prefix - * is undeclared in this context. - * @see #getPrefix - * @see #getPrefixes - */ - public String getURI (String prefix) - { - return currentContext.getURI(prefix); - } - - - /** - * Return an enumeration of all prefixes currently declared. - * - * <p><strong>Note:</strong> if there is a default prefix, it will not be - * returned in this enumeration; check for the default prefix - * using the {@link #getURI getURI} with an argument of "".</p> - * - * @return An enumeration of all prefixes declared in the - * current context except for the empty (default) - * prefix. - * @see #getDeclaredPrefixes - * @see #getURI - */ - public Enumeration getPrefixes () - { - return currentContext.getPrefixes(); - } - - - /** - * Return one of the prefixes mapped to a Namespace URI. - * - * <p>If more than one prefix is currently mapped to the same - * URI, this method will make an arbitrary selection; if you - * want all of the prefixes, use the {@link #getPrefixes} - * method instead.</p> - * - * <p><strong>Note:</strong> this will never return the empty - * (default) prefix; to check for a default prefix, use the {@link - * #getURI getURI} method with an argument of "".</p> - * - * @param uri The Namespace URI. - * @return One of the prefixes currently mapped to the URI supplied, - * or null if none is mapped or if the URI is assigned to - * the default Namespace. - * @see #getPrefixes(java.lang.String) - * @see #getURI */ - public String getPrefix (String uri) - { - return currentContext.getPrefix(uri); - } - - - /** - * Return an enumeration of all prefixes currently declared for a URI. - * - * <p>This method returns prefixes mapped to a specific Namespace - * URI. The xml: prefix will be included. If you want only one - * prefix that's mapped to the Namespace URI, and you don't care - * which one you get, use the {@link #getPrefix getPrefix} - * method instead.</p> - * - * <p><strong>Note:</strong> the empty (default) prefix is - * <em>never</em> included in this enumeration; to check for the - * presence of a default Namespace, use the {@link #getURI getURI} - * method with an argument of "".</p> - * - * @param uri The Namespace URI. - * @return An enumeration of all prefixes declared in the - * current context. - * @see #getPrefix - * @see #getDeclaredPrefixes - * @see #getURI */ - public Enumeration getPrefixes (String uri) - { - // JJK: The old code involved creating a vector, filling it - // with all the matching prefixes, and then getting its - // elements enumerator. Wastes storage, wastes cycles if we - // don't actually need them all. Better to either implement - // a specific enumerator for these prefixes... or a filter - // around the all-prefixes enumerator, which comes out to - // roughly the same thing. - // - // **** Currently a filter. That may not be most efficient - // when I'm done restructuring storage! - return new PrefixForUriEnumerator(this,uri,getPrefixes()); - } - - - /** - * Return an enumeration of all prefixes declared in this context. - * - * <p>The empty (default) prefix will be included in this - * enumeration; note that this behaviour differs from that of - * {@link #getPrefix} and {@link #getPrefixes}.</p> - * - * @return An enumeration of all prefixes declared in this - * context. - * @see #getPrefixes - * @see #getURI - */ - public Enumeration getDeclaredPrefixes () - { - return currentContext.getDeclaredPrefixes(); - } - - - -} - -//////////////////////////////////////////////////////////////////// -// Local classes. -// These were _internal_ classes... but in fact they don't have to be, -// and may be more efficient if they aren't. -//////////////////////////////////////////////////////////////////// - -/** - * Implementation of Enumeration filter, wrapped - * aroung the get-all-prefixes version of the operation. This is NOT - * necessarily the most efficient approach; finding the URI and then asking - * what prefixes apply to it might make much more sense. - */ -class PrefixForUriEnumerator implements Enumeration -{ - private Enumeration allPrefixes; - private String uri; - private String lookahead=null; - private NamespaceSupport2 nsup; - - // Kluge: Since one can't do a constructor on an - // anonymous class (as far as I know)... - PrefixForUriEnumerator(NamespaceSupport2 nsup,String uri, Enumeration allPrefixes) - { - this.nsup=nsup; - this.uri=uri; - this.allPrefixes=allPrefixes; - } - - public boolean hasMoreElements() - { - if(lookahead!=null) - return true; - - while(allPrefixes.hasMoreElements()) - { - String prefix=(String)allPrefixes.nextElement(); - if(uri.equals(nsup.getURI(prefix))) - { - lookahead=prefix; - return true; - } - } - return false; - } - - public Object nextElement() - { - if(hasMoreElements()) - { - String tmp=lookahead; - lookahead=null; - return tmp; - } - else - throw new java.util.NoSuchElementException(); - } -} - -/** - * Internal class for a single Namespace context. - * - * <p>This module caches and reuses Namespace contexts, so the number allocated - * will be equal to the element depth of the document, not to the total - * number of elements (i.e. 5-10 rather than tens of thousands).</p> - */ -final class Context2 { - - //////////////////////////////////////////////////////////////// - // Manefest Constants - //////////////////////////////////////////////////////////////// - - /** - * An empty enumeration. - */ - private final static Enumeration EMPTY_ENUMERATION = - new Vector().elements(); - - //////////////////////////////////////////////////////////////// - // Protected state. - //////////////////////////////////////////////////////////////// - - Hashtable prefixTable; - Hashtable uriTable; - Hashtable elementNameTable; - Hashtable attributeNameTable; - String defaultNS = null; - - //////////////////////////////////////////////////////////////// - // Internal state. - //////////////////////////////////////////////////////////////// - - private Vector declarations = null; - private boolean tablesDirty = false; - private Context2 parent = null; - private Context2 child = null; - - /** - * Create a new Namespace context. - */ - Context2 (Context2 parent) - { - if(parent==null) - { - prefixTable = new Hashtable(); - uriTable = new Hashtable(); - elementNameTable=null; - attributeNameTable=null; - } - else - setParent(parent); - } - - - /** - * @returns The child Namespace context object, or null if this - * is the last currently on the chain. - */ - Context2 getChild() - { - return child; - } - - /** - * @returns The parent Namespace context object, or null if this - * is the root. - */ - Context2 getParent() - { - return parent; - } - - /** - * (Re)set the parent of this Namespace context. - * This is separate from the c'tor because it's re-applied - * when a Context2 is reused by push-after-pop. - * - * @param parent The parent Namespace context object. - */ - void setParent (Context2 parent) - { - this.parent = parent; - parent.child = this; // JJK: Doubly-linked - declarations = null; - prefixTable = parent.prefixTable; - uriTable = parent.uriTable; - elementNameTable = parent.elementNameTable; - attributeNameTable = parent.attributeNameTable; - defaultNS = parent.defaultNS; - tablesDirty = false; - } - - - /** - * Declare a Namespace prefix for this context. - * - * @param prefix The prefix to declare. - * @param uri The associated Namespace URI. - * @see org.xml.sax.helpers.NamespaceSupport2#declarePrefix - */ - void declarePrefix (String prefix, String uri) - { - // Lazy processing... - if (!tablesDirty) { - copyTables(); - } - if (declarations == null) { - declarations = new Vector(); - } - - prefix = prefix.intern(); - uri = uri.intern(); - if ("".equals(prefix)) { - if ("".equals(uri)) { - defaultNS = null; - } else { - defaultNS = uri; - } - } else { - prefixTable.put(prefix, uri); - uriTable.put(uri, prefix); // may wipe out another prefix - } - declarations.addElement(prefix); - } - - - /** - * Process a raw XML 1.0 name in this context. - * - * @param qName The raw XML 1.0 name. - * @param isAttribute true if this is an attribute name. - * @return An array of three strings containing the - * URI part (or empty string), the local part, - * and the raw name, all internalized, or null - * if there is an undeclared prefix. - * @see org.xml.sax.helpers.NamespaceSupport2#processName - */ - String [] processName (String qName, boolean isAttribute) - { - String name[]; - Hashtable table; - - // Select the appropriate table. - if (isAttribute) { - if(elementNameTable==null) - elementNameTable=new Hashtable(); - table = elementNameTable; - } else { - if(attributeNameTable==null) - attributeNameTable=new Hashtable(); - table = attributeNameTable; - } - - // Start by looking in the cache, and - // return immediately if the name - // is already known in this content - name = (String[])table.get(qName); - if (name != null) { - return name; - } - - // We haven't seen this name in this - // context before. - name = new String[3]; - int index = qName.indexOf(':'); - - - // No prefix. - if (index == -1) { - if (isAttribute || defaultNS == null) { - name[0] = ""; - } else { - name[0] = defaultNS; - } - name[1] = qName.intern(); - name[2] = name[1]; - } - - // Prefix - else { - String prefix = qName.substring(0, index); - String local = qName.substring(index+1); - String uri; - if ("".equals(prefix)) { - uri = defaultNS; - } else { - uri = (String)prefixTable.get(prefix); - } - if (uri == null) { - return null; - } - name[0] = uri; - name[1] = local.intern(); - name[2] = qName.intern(); - } - - // Save in the cache for future use. - table.put(name[2], name); - tablesDirty = true; - return name; - } - - - /** - * Look up the URI associated with a prefix in this context. - * - * @param prefix The prefix to look up. - * @return The associated Namespace URI, or null if none is - * declared. - * @see org.xml.sax.helpers.NamespaceSupport2#getURI - */ - String getURI (String prefix) - { - if ("".equals(prefix)) { - return defaultNS; - } else if (prefixTable == null) { - return null; - } else { - return (String)prefixTable.get(prefix); - } - } - - - /** - * Look up one of the prefixes associated with a URI in this context. - * - * <p>Since many prefixes may be mapped to the same URI, - * the return value may be unreliable.</p> - * - * @param uri The URI to look up. - * @return The associated prefix, or null if none is declared. - * @see org.xml.sax.helpers.NamespaceSupport2#getPrefix - */ - String getPrefix (String uri) - { - if (uriTable == null) { - return null; - } else { - return (String)uriTable.get(uri); - } - } - - - /** - * Return an enumeration of prefixes declared in this context. - * - * @return An enumeration of prefixes (possibly empty). - * @see org.xml.sax.helpers.NamespaceSupport2#getDeclaredPrefixes - */ - Enumeration getDeclaredPrefixes () - { - if (declarations == null) { - return EMPTY_ENUMERATION; - } else { - return declarations.elements(); - } - } - - - /** - * Return an enumeration of all prefixes currently in force. - * - * <p>The default prefix, if in force, is <em>not</em> - * returned, and will have to be checked for separately.</p> - * - * @return An enumeration of prefixes (never empty). - * @see org.xml.sax.helpers.NamespaceSupport2#getPrefixes - */ - Enumeration getPrefixes () - { - if (prefixTable == null) { - return EMPTY_ENUMERATION; - } else { - return prefixTable.keys(); - } - } - - //////////////////////////////////////////////////////////////// - // Internal methods. - //////////////////////////////////////////////////////////////// - - /** - * Copy on write for the internal tables in this context. - * - * <p>This class is optimized for the normal case where most - * elements do not contain Namespace declarations. In that case, - * the Context2 will share data structures with its parent. - * New tables are obtained only when new declarations are issued, - * so they can be popped off the stack.</p> - * - * <p> JJK: **** Alternative: each Context2 might declare - * _only_ its local bindings, and delegate upward if not found.</p> - */ - private void copyTables () - { - // Start by copying our parent's bindings - prefixTable = (Hashtable)prefixTable.clone(); - uriTable = (Hashtable)uriTable.clone(); - - // Replace the caches with empty ones, rather than - // trying to determine which bindings should be flushed. - // As far as I can tell, these caches are never actually - // used in Xalan... More efficient to remove the whole - // cache system? **** - if(elementNameTable!=null) - elementNameTable=new Hashtable(); - if(attributeNameTable!=null) - attributeNameTable=new Hashtable(); - tablesDirty = true; - } - -} - - -// end of NamespaceSupport2.java |