/*
 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package java.nio;

import java.util.Comparator;
import java.util.Spliterator;
import java.util.function.IntConsumer;

/**
 * A Spliterator.OfInt for sources that traverse and split elements
 * maintained in a CharBuffer.
 *
 * @implNote
 * The implementation is based on the code for the Array-based spliterators.
 */
class CharBufferSpliterator implements Spliterator.OfInt {
 private final CharBuffer buffer;
 private int index; // current index, modified on advance/split
 private final int limit;

 CharBufferSpliterator(CharBuffer buffer) {
 this(buffer, buffer.position(), buffer.limit());
 }

 CharBufferSpliterator(CharBuffer buffer, int origin, int limit) {
 assert origin <= limit;
 this.buffer = buffer;
 this.index = (origin <= limit) ? origin : limit;
 this.limit = limit;
 }

 @Override
 public OfInt trySplit() {
 int lo = index, mid = (lo + limit) >>> 1;
 return (lo >= mid)
 ? null
 : new CharBufferSpliterator(buffer, lo, index = mid);
 }

 @Override
 public void forEachRemaining(IntConsumer action) {
 if (action == null)
 throw new NullPointerException();
 CharBuffer cb = buffer;
 int i = index;
 int hi = limit;
 index = hi;
 while (i < hi) {
 action.accept(cb.getUnchecked(i++));
 }
 }

 @Override
 public boolean tryAdvance(IntConsumer action) {
 if (action == null)
 throw new NullPointerException();
 if (index >= 0 && index < limit) {
 action.accept(buffer.getUnchecked(index++));
 return true;
 }
 return false;
 }

 @Override
 public long estimateSize() {
 return (long)(limit - index);
 }

 @Override
 public int characteristics() {
 return Buffer.SPLITERATOR_CHARACTERISTICS;
 }
}