soot.util.queue.BDDReader.jedd Maven / Gradle / Ivy
/* Soot - a J*va Optimization Framework
* Copyright (C) 2003 Ondrej Lhotak
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
package soot.util.queue;
/** Similar to ChunkedQueue, but implemented using BDDs. A BDDQueue represents
* a sequence of BDDs. Each reader points to some BDD in the sequence, and
* can read the current BDD and ones that come after it in sequence. If at
* any point, a BDD in the sequence no longer has a reader pointing to it,
* it is unioned into the preceding BDD (if any) and removed from the sequence.
* Only BDDs that have not been read by all the readers
* are kept. A reader can only read the BDDs added to the queue
* after the reader was created.
* @author Ondrej Lhotak
*/
public class BDDReader implements Cloneable {
BDDChunk chunk;
BDDQueue q;
BDDReader( BDDQueue q ) {
this.q = q;
chunk = q.newChunk();
}
public <> next() {
<> ret;
do {
ret = chunk.bdd;
chunk = chunk.next;
if( chunk == null ) chunk = q.newChunk();
} while( ret == 0B && chunk.next != null );
return ret;
}
public boolean hasNext() {
while( chunk.bdd == 0B && chunk.next != null ) chunk = chunk.next;
return chunk.bdd != 0B;
}
private BDDReader( BDDQueue q, BDDChunk chunk ) {
this.q = q;
this.chunk = chunk;
}
public Object clone() {
return new BDDReader(q, chunk);
}
}