/*

 * Copyright (c) 2001, 2011, 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

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

 * questions.

 */

package jdk.internal.reflect;

/** It is necessary to use a "bootstrap" UTF-8 encoder for encoding

    constant pool entries because the character set converters rely on

    Class.newInstance(). */

class UTF8 {

    // This encoder is not quite correct.  It does not handle surrogate pairs.

    static byte[] encode(String str) {

        int len = str.length();

        byte[] res = new byte[utf8Length(str)];

        int utf8Idx = 0;

        try {

            for (int i = 0; i < len; i++) {

                int c = str.charAt(i) & 0xFFFF;

                if (c >= 0x0001 && c <= 0x007F) {

                    res[utf8Idx++] = (byte) c;

                } else if (c == 0x0000 ||

                           (c >= 0x0080 && c <= 0x07FF)) {

                    res[utf8Idx++] = (byte) (0xC0 + (c >> 6));

                    res[utf8Idx++] = (byte) (0x80 + (c & 0x3F));

                } else {

                    res[utf8Idx++] = (byte) (0xE0 + (c >> 12));

                    res[utf8Idx++] = (byte) (0x80 + ((c >> 6) & 0x3F));

                    res[utf8Idx++] = (byte) (0x80 + (c & 0x3F));

                }

            }

        } catch (ArrayIndexOutOfBoundsException e) {

            throw new InternalError

                ("Bug in sun.reflect bootstrap UTF-8 encoder", e);

        }

        return res;

    }

    private static int utf8Length(String str) {

        int len = str.length();

        int utf8Len = 0;

        for (int i = 0; i < len; i++) {

            int c = str.charAt(i) & 0xFFFF;

            if (c >= 0x0001 && c <= 0x007F) {

                utf8Len += 1;

            } else if (c == 0x0000 ||

                       (c >= 0x0080 && c <= 0x07FF)) {

                utf8Len += 2;

            } else {

                utf8Len += 3;

            }

        }

        return utf8Len;

    }

}