/*

 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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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;

    }

}