/*

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 * THIS FILE WAS MODIFIED BY SUN MICROSYSTEMS, INC.

 */

package com.sun.xml.internal.fastinfoset.util;

public class CharArray implements CharSequence {

    public char[] ch;

    public int start;

    public int length;

    protected int _hash;

    protected CharArray() {

    }

    public CharArray(char[] _ch, int _start, int _length, boolean copy) {

        set(_ch, _start, _length, copy);

    }

    public final void set(char[] _ch, int _start, int _length, boolean copy) {

        if (copy) {

            ch = new char[_length];

            start = 0;

            length = _length;

            System.arraycopy(_ch, _start, ch, 0, _length);

        } else {

            ch = _ch;

            start = _start;

            length = _length;

        }

        _hash = 0;

    }

    public final void cloneArray() {

        char[] _ch = new char[length];

        System.arraycopy(ch, start, _ch, 0, length);

        ch = _ch;

        start = 0;

    }

    public String toString() {

        return new String(ch, start, length);

    }

    public int hashCode() {

        if (_hash == 0) {

            // Same hash code algorithm as used for String

            // s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]

            for (int i = start; i < start + length; i++) {

                _hash = 31*_hash + ch[i];

            }

        }

        return _hash;

    }

    public static final int hashCode(char[] ch, int start, int length) {

        // Same hash code algorithm as used for String

        // s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]

        int hash = 0;

        for (int i = start; i < start + length; i++) {

            hash = 31*hash + ch[i];

        }

        return hash;

    }

    public final boolean equalsCharArray(CharArray cha) {

        if (this == cha) {

            return true;

        }

        if (length == cha.length) {

            int n = length;

            int i = start;

            int j = cha.start;

            while (n-- != 0) {

                if (ch[i++] != cha.ch[j++])

                    return false;

            }

            return true;

        }

        return false;

    }

    public final boolean equalsCharArray(char[] ch, int start, int length) {

        if (this.length == length) {

            int n = this.length;

            int i = this.start;

            int j = start;

            while (n-- != 0) {

                if (this.ch[i++] != ch[j++])

                    return false;

            }

            return true;

        }

        return false;

    }

    public boolean equals(Object obj) {

        if (this == obj) {

            return true;

        }

        if (obj instanceof CharArray) {

            CharArray cha = (CharArray)obj;

            if (length == cha.length) {

                int n = length;

                int i = start;

                int j = cha.start;

                while (n-- != 0) {

                    if (ch[i++] != cha.ch[j++])

                        return false;

                }

                return true;

            }

        }

        return false;

    }

    // CharSequence interface

    public final int length() {

        return length;

    }

    public final char charAt(int index) {

        return ch[start + index];

    }

    public final CharSequence subSequence(int start, int end) {

        return new CharArray(ch, this.start + start, end - start, false);

    }

}