/*
* Copyright (c) 2005, The Regents of the University of California, through
* Lawrence Berkeley National Laboratory (subject to receipt of any required
* approvals from the U.S. Dept. of Energy). All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* (1) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* (2) Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* (3) Neither the name of the University of California, Lawrence Berkeley
* National Laboratory, U.S. Dept. of Energy nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* You are under no obligation whatsoever to provide any bug fixes, patches, or
* upgrades to the features, functionality or performance of the source code
* ("Enhancements") to anyone; however, if you choose to make your Enhancements
* available either publicly, or directly to Lawrence Berkeley National
* Laboratory, without imposing a separate written license agreement for such
* Enhancements, then you hereby grant the following license: a non-exclusive,
* royalty-free perpetual license to install, use, modify, prepare derivative
* works, incorporate into other computer software, distribute, and sublicense
* such enhancements or derivative works thereof, in binary and source code
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*/
package nux.xom.binary;
import nu.xom.Attribute;
import nu.xom.Element;
/**
* EXPERIMENTAL; Not part of published API; Subject to change or removal without
* notice. Wishing Java had "friends" to make select internal classes visible
* across package boundaries...
* <p>
* Small fast utility for efficient construction of elements and attributes.
* Implemented via a LRU cache of the most recent elements and attributes.
* <p>
* Avoids repeated XML reverification in XOM Element and Attribute constructor
* on cache hit, plus avoids generating new String objects by quasi "interning"
* localName and prefix, which in turn reduces memory consumption. Has overhead
* close to zero on cache miss.
* <p>
* This implementation is not thread-safe.
* <p>
* This class would become obsolete if the XOM Element and Attribute classes
* would have an internal LRU cache of QNames.
*
* @author whoschek.AT.lbl.DOT.gov
* @author $Author: hoschek3 $
* @version $Revision: 1.7 $, $Date: 2006/01/02 01:08:51 $
*/
public final class NodeBuilder {
private final LRUHashMap2 elements;
private final LRUHashMap2 attributes;
/** Constructs a new instance. */
public NodeBuilder() {
this(512);
}
/** Constructs a new instance that can hold at most maxSize entries. */
private NodeBuilder(int maxSize) {
this.elements = new LRUHashMap2(maxSize);
this.attributes = new LRUHashMap2(maxSize);
}
/**
* Contructs and returns a new element for the given qualified name and
* namespace URI.
*
* @param qname
* the qualified name of the element (must not be null)
* @param uri
* the namespace URI of the element
* @return a new element
*/
public Element createElement(String qname, String uri) {
if (uri == null) uri = "";
Element elem = (Element) elements.get(qname, uri);
if (elem == null) {
elem = new Element(qname, uri);
elements.put(qname, uri, elem);
}
return new Element(elem); // copy constructor is fast
}
/**
* Contructs and returns a new attribute for the given qualified name and
* namespace URI.
*
* @param qname
* the qualified name of the attribute (must not be null)
* @param uri
* the namespace URI of the attribute
* @param value
* the attribute value (must not be null)
* @param type
* the attribute type (must not be null)
* @return a new attribute
*/
public Attribute createAttribute(String qname, String uri, String value, Attribute.Type type) {
if (uri == null) uri = "";
if ("xml:id".equals(qname)) {
type = Attribute.Type.ID; // avoids exception in Attribute.setType()
}
Attribute attr = (Attribute) attributes.get(qname, uri);
if (attr == null) {
attr = new Attribute(qname, uri, value, type);
attributes.put(qname, uri, attr);
return new Attribute(attr); // copy constructor is fast
}
attr = new Attribute(attr); // copy constructor is fast
if (attr.getType() != type) attr.setType(type);
attr.setValue(value);
return attr;
}
}