/*
The MIT License (MIT)
Copyright (c) 2016 Pierre Lindenbaum
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
History:
* 2014 creation
*/
package com.github.lindenb.jvarkit.util;
import htsjdk.samtools.util.AbstractIterator;
import htsjdk.samtools.util.CloseableIterator;
import htsjdk.samtools.util.CloserUtil;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;
public class EqualRangeIterator<T>
extends AbstractIterator<List<T>>
implements CloseableIterator<List<T>>
{
private Iterator<T> delegate;
private final Comparator<T> comparator;
private Optional<T> lastPeek = Optional.empty();
public EqualRangeIterator(
final Iterator<T> delegate,
final Comparator<T> comparator)
{
this.delegate = delegate;
this.comparator = comparator;
}
@Override
protected List<T> advance() {
if(this.delegate==null) throw new IllegalStateException("iterator closed");
final List<T> buffer=new ArrayList<>();
if(lastPeek.isPresent()) {
buffer.add(lastPeek.get());
lastPeek = Optional.empty();
}
while(this.delegate.hasNext()) {
final T curr = this.delegate.next();
if(buffer.isEmpty()) {
buffer.add(curr);
}
else
{
final int d= this.comparator.compare(buffer.get(0), curr);
if(d==0 ) {
buffer.add(curr);
}
else if(d < 0) {
this.lastPeek = Optional.of(curr);
break;
}
else {
throw new IllegalStateException("got "+curr +" after "+ buffer.get(0));
}
}
}
return buffer.isEmpty()?null:buffer;
}
@Override
public void close() {
CloserUtil.close(this.delegate);
this.delegate = null;
}
}