/*

 * Copyright (c) 2001, 2010, 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 java.io;

/**

 * Utility methods for packing/unpacking primitive values in/out of byte arrays

 * using big-endian byte ordering.

 */

class Bits {

    /*

     * Methods for unpacking primitive values from byte arrays starting at

     * given offsets.

     */

    static boolean getBoolean(byte[] b, int off) {

        return b[off] != 0;

    }

    static char getChar(byte[] b, int off) {

        return (char) ((b[off + 1] & 0xFF) +

                       (b[off] << 8));

    }

    static short getShort(byte[] b, int off) {

        return (short) ((b[off + 1] & 0xFF) +

                        (b[off] << 8));

    }

    static int getInt(byte[] b, int off) {

        return ((b[off + 3] & 0xFF)      ) +

               ((b[off + 2] & 0xFF) <<  8) +

               ((b[off + 1] & 0xFF) << 16) +

               ((b[off    ]       ) << 24);

    }

    static float getFloat(byte[] b, int off) {

        return Float.intBitsToFloat(getInt(b, off));

    }

    static long getLong(byte[] b, int off) {

        return ((b[off + 7] & 0xFFL)      ) +

               ((b[off + 6] & 0xFFL) <<  8) +

               ((b[off + 5] & 0xFFL) << 16) +

               ((b[off + 4] & 0xFFL) << 24) +

               ((b[off + 3] & 0xFFL) << 32) +

               ((b[off + 2] & 0xFFL) << 40) +

               ((b[off + 1] & 0xFFL) << 48) +

               (((long) b[off])      << 56);

    }

    static double getDouble(byte[] b, int off) {

        return Double.longBitsToDouble(getLong(b, off));

    }

    /*

     * Methods for packing primitive values into byte arrays starting at given

     * offsets.

     */

    static void putBoolean(byte[] b, int off, boolean val) {

        b[off] = (byte) (val ? 1 : 0);

    }

    static void putChar(byte[] b, int off, char val) {

        b[off + 1] = (byte) (val      );

        b[off    ] = (byte) (val >>> 8);

    }

    static void putShort(byte[] b, int off, short val) {

        b[off + 1] = (byte) (val      );

        b[off    ] = (byte) (val >>> 8);

    }

    static void putInt(byte[] b, int off, int val) {

        b[off + 3] = (byte) (val       );

        b[off + 2] = (byte) (val >>>  8);

        b[off + 1] = (byte) (val >>> 16);

        b[off    ] = (byte) (val >>> 24);

    }

    static void putFloat(byte[] b, int off, float val) {

        putInt(b, off,  Float.floatToIntBits(val));

    }

    static void putLong(byte[] b, int off, long val) {

        b[off + 7] = (byte) (val       );

        b[off + 6] = (byte) (val >>>  8);

        b[off + 5] = (byte) (val >>> 16);

        b[off + 4] = (byte) (val >>> 24);

        b[off + 3] = (byte) (val >>> 32);

        b[off + 2] = (byte) (val >>> 40);

        b[off + 1] = (byte) (val >>> 48);

        b[off    ] = (byte) (val >>> 56);

    }

    static void putDouble(byte[] b, int off, double val) {

        putLong(b, off, Double.doubleToLongBits(val));

    }

}