jkesselm 01/08/03 11:38:15
Modified: java/src/org/apache/xml/utils NamespaceSupport2.java
Log:
More efficient prefixes-for-specific-URI. This may wind up being
redone yet again if/when the underlying storage representation
changes.
Revision Changes Path
1.3 +74 -23
xml-xalan/java/src/org/apache/xml/utils/NamespaceSupport2.java
Index: NamespaceSupport2.java
===================================================================
RCS file:
/home/cvs/xml-xalan/java/src/org/apache/xml/utils/NamespaceSupport2.java,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -r1.2 -r1.3
--- NamespaceSupport2.java 2001/08/03 17:30:04 1.2
+++ NamespaceSupport2.java 2001/08/03 18:38:14 1.3
@@ -293,7 +293,7 @@
// JJK: This recopying is required because processName may return
// a cached result. I Don't Like It. *****
- System.arrayCopy(name,0,parts,0,3);
+ System.arraycopy(name,0,parts,0,3);
return parts;
}
@@ -343,19 +343,16 @@
* want all of the prefixes, use the [EMAIL PROTECTED] #getPrefixes}
* method instead.</p>
*
- * <p><strong>Note:</strong> this will never return the empty (default)
prefix;
- * to check for a default prefix, use the [EMAIL PROTECTED] #getURI
getURI}
- * method with an argument of "".</p>
+ * <p><strong>Note:</strong> this will never return the empty
+ * (default) prefix; to check for a default prefix, use the [EMAIL
PROTECTED]
+ * #getURI getURI} method with an argument of "".</p>
*
* @param uri The Namespace URI.
- * @param isAttribute true if this prefix is for an attribute
- * (and the default Namespace is not allowed).
* @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
- */
+ * @see #getURI */
public String getPrefix (String uri)
{
return currentContext.getPrefix(uri);
@@ -371,29 +368,83 @@
* which one you get, use the [EMAIL PROTECTED] #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 [EMAIL PROTECTED] #getURI getURI} method with an
- * argument of "".</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 [EMAIL PROTECTED] #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
- */
+ * @see #getURI */
public Enumeration getPrefixes (String uri)
{
- Vector prefixes = new Vector();
- Enumeration allPrefixes = getPrefixes();
- while (allPrefixes.hasMoreElements()) {
- String prefix = (String)allPrefixes.nextElement();
- if (uri.equals(getURI(prefix))) {
- prefixes.addElement(prefix);
- }
- }
- return prefixes.elements();
+ // 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.
+
+// Vector prefixes = new Vector();
+// Enumeration allPrefixes = getPrefixes();
+// while (allPrefixes.hasMoreElements()) {
+// String prefix = (String)allPrefixes.nextElement();
+// if (uri.equals(getURI(prefix))) {
+// prefixes.addElement(prefix);
+// }
+// }
+// return prefixes.elements();
+
+ // Anonymous implementation of Enumeration filter, wrapped
+ // aroung the get-all-prefixes version of the operation.
+ return new Enumeration()
+ {
+ private Enumeration allPrefixes;
+ private String uri;
+ private String lookahead=null;
+
+ // Kluge: Since one can't do a constructor on an
+ // anonymous class (as far as I know)...
+ Enumeration setup(String uri, Enumeration allPrefixes)
+ {
+ this.uri=uri;
+ this.allPrefixes=allPrefixes;
+ return this;
+ }
+
+ public boolean hasMoreElements()
+ {
+ if(lookahead!=null)
+ return true;
+
+ while(allPrefixes.hasMoreElements())
+ {
+ String prefix=(String)allPrefixes.nextElement();
+ if(uri.equals(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();
+ }
+ }.setup(uri,getPrefixes());
}
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
